Abstract
BACKGROUND: Only scarce information is available on the long-term outcome and the natural course of children with infantile spinal muscular atrophy with respiratory distress type 1 (SMARD1) due to mutations in the IGHMBP2 gene.
OBJECTIVE: To describe the natural disease course, to systematically quantify the residual capacities of children with SMARD1 who survive on permanent mechanical respiration, and to identify markers predicting the disease outcome at the time of manifestation.
METHODS: We conducted a longitudinal study of 11 infantile SMARD1 patients over a mean observational period of 7.8 (SD 3.2) years. Disease-specific features were continuously assessed by using a semiquantitative scoring system. Additionally, we analyzed the residual enzymatic activity of 6 IGHMBP2 mutants in our patients.
RESULTS: After an initial rapid decline of the clinical score until the age of 2 years, residual capabilities reached a plateau or even improved. The overall clinical outcome was markedly heterogeneous, but clinical scores at the age of 3 months showed a positive linear correlation with the clinical outcome at 1 year and at 4 years of age. If expressed in an in vitro recombinant system, mutations of patients with more favorable outcomes retained residual enzymatic activity.
CONCLUSIONS: Despite their severe disabilities and symptoms, most SMARD1 patients are well integrated into their home environment and two thirds of them are able to attend kindergarten or school. This information will help to counsel parents at the time of disease manifestation.

Abstract
Motor neurons typically have very long axons, and fine-tuning axonal transport is crucial for their survival. The obstruction of axonal transport is gaining attention as a cause of neuronal dysfunction in a variety of neurodegenerative motor neuron diseases. Depletions in dynein and dynactin-1, motor molecules regulating axonal trafficking, disrupt axonal transport in flies, and mutations in their genes cause motor neuron degeneration in humans and rodents. Axonal transport defects are among the early molecular events leading to neurodegeneration in mouse models of amyotrophic lateral sclerosis (ALS). Gene expression profiles indicate that dynactin-1 mRNA is downregulated in degenerating spinal motor neurons of autopsied patients with sporadic ALS. Dynactin-1 mRNA is also reduced in the affected neurons of a mouse model of spinal and bulbar muscular atrophy, a motor neuron disease caused by triplet CAG repeat expansion in the gene encoding the androgen receptor. Pathogenic androgen receptor proteins also inhibit kinesin-1 microtubule-binding activity and disrupt anterograde axonal transport by activating c-Jun N-terminal kinase. Disruption of axonal transport also underlies the pathogenesis of spinal muscular atrophy and hereditary spastic paraplegias. These observations suggest that the impairment of axonal transport is a key event in the pathological processes of motor neuron degeneration and an important target of therapy development for motor neuron diseases.

Abstract
INTRODUCTION: Proximal spinal muscular atrophy (SMA) is a common autosomal recessively inherited neuromuscular disorder. It is caused by homozygous absence of the survival motor neuron 1 (SMN1) gene. SMN2, which modulates the severity of the disease, represents a major target for therapy. The aim of this study was to investigate whether SMN2 expression can be increased by caffeic acid, chlorogenic acid and curcumin, which are designed by modifications of the carboxylic acid class of histone deacetylase (HDAC) inhibitors.
MATERIAL AND METHODS: Using quantitative real-time PCR, we analysed the levels of full-length SMN2 and ?7SMN2 mRNA. We performed LDH cytotoxicity assay to analyse whether SMN2 activating concentrations of caffeic acid, chlorogenic acid and curcumin were cytotoxic to fibroblasts.
RESULTS: We found that caffeic acid and curcumin were more efficient than chlorogenic acid and increased full-length SMN2 mRNA levels 1.5 and 1.7-fold, respectively. ?7SMN2 mRNA levels were measured to investigate alternative splicing of exon 7. We also found that cytotoxicity was not observed at SMN2 activating concentrations.
CONCLUSIONS: Our data suggest that carboxylic acid derivatives including phenolic structure and symmetry could be a good candidate for SMA treatment.

Abstract
Spinal muscular atrophy (SMA) is a leading genetic cause of infantile death. Loss of a gene called Survival Motor Neuron 1 (SMN1) and, as a result, reduced levels of the Survival Motor Neuron (SMN) protein leads to SMA development. SMA is characterized by the loss of functional motor neurons in the spinal cord. However, accumulating evidence suggests the contribution of other organs to the composite SMA phenotype and disease progression. A growing number of congenital heart defects have been identified in severe SMA patients. Consistent with the clinical cases, we have recently identified developmental and functional heart defects in two SMA mouse models, occurring at embryonic stage in a severe SMA model and shortly after birth in a less severe model (SMN?7). Our goal was to examine the late stage cardiac abnormalities in untreated SMN?7 mice and to determine whether gene replacement therapy restores cardiac structure/function in rescued SMN?7 model. To reveal the extent of the cardiac structural/functional repair in the rescued mice, we analyzed the heart of untreated and treated SMN?7 model using self-complementary Adeno-associated virus (serotype 9) expressing the full-length SMN cDNA. We examined the characteristics of the heart failure such as remodeling, fibrosis, oxidative stress, and vascular integrity in both groups. Our results clearly indicate that fibrosis, oxidative stress activation, vascular remodeling, and a significant decrease in the number of capillaries exist in the SMA heart. The cardiac structural defects were improved drastically in the rescued animals, however, the level of impairment was still significant compared to the age-matched wildtype littermates. Furthermore, functional analysis by in vivo cardiac magnetic resonance imaging (MRI) revealed that the heart of the treated SMA mice still exhibits functional defects. In conclusion, cardiac abnormalities are only partially rescued in post-birth treated SMA animals and these abnormalities may contribute to the premature death of vector-treated SMA animals with seemingly rescued motor function but an average life span of less than 70days as reported in several studies.

Abstract
A 15 year old boy with SMA type II underwent spinal fusion and suffered a mitochondrial Reye-like catabolic crisis 4 days postop with hypoketotic hypoglycemia, lactic acidaemia, hyperammonemia and liver failure, with 90% coagulative necrosis and diffuse macro- and microvesicular steatosis, requiring orthotopic liver transplantation. This crisis responded in part to mitochondrial therapy and anabolic rescue. He made a dramatic sustained neurological recovery, though his post-transplant liver biopsies revealed micro- and macrosteatosis. We hypothesize that a combination of surgical stress-catecholamine induced lipolysis, prolonged general anaesthesia with propofol and sevoflurane, and perioperative fasting on a background of decreased ?-oxidation were potential risk factors for the mitochondrial decompensation.

Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disorder that is characterized by progressive loss of motor neuron function. It is caused by the homozygous loss of the SMN1 (survival of motor neuron 1) gene and a decrease in full-length SMN protein. SMN2 is a nearly identical homolog of SMN1 that, due to alternative splicing, expresses predominantly truncated SMN protein. SMN2 represents an enticing therapeutic target. Increasing expression of full-length SMN from the SMN2 gene might represent a treatment for SMA. We describe a newly designed cell-based reporter assay that faithfully and reproducibly measures full-length SMN expression from the SMN2 gene. This reporter can detect increases of SMN protein by an array of compounds previously shown to regulate SMN2 expression and by the overexpression of proteins that modulate SMN2 splicing. It also can be used to evaluate changes at both the transcriptional and splicing level. This assay can be a valuable tool for the identification of novel compounds that increase SMN2 protein levels and the optimization of compounds already known to modulate SMN2 expression. We present here preliminary data from a high-throughput screen using this assay to identify novel compounds that increase expression of SMN2.

Abstract
Background and purpose:? Spinal muscular atrophy (SMA) is a progressive neuromuscular disease. Since disease severity is related to the amount of survival motor neuron (SMN) protein, up-regulated functional SMN protein levels from the SMN2 gene is considered a major SMA drug-discovery strategy. In this study, we explore triptolide, a diterpene triepoxide purified from Tripterygium wilfordiiHook. F., as a new target increasing SMN protein. Experimental approach:? The effects and mechanisms of triptolide on the production of SMA protein were determined by cell-based assays using motor neuronal cell line NSC34 and skin fibroblasts from SMA patients. Wild-type (Smn(+/+) SMN2(-/-) , C57BL/6) and SMA-like (Smn(-/- ) SMN2) mice received triptolide (0.01 or 0.1 mg kg(-1)day(-1) ) by intraperitoneal injection to examine the survival rate and the level of change in SMN protein in neurons and muscle tissue. Key results:? In NSC34 cells and human SMA fibroblasts, triptolide at picromolar concentration significantly increased SMN protein expression and SMN complex component (Gemin2 and Gemin3) amounts. In human SMA fibroblasts, triptolide increased SMN-containing nuclear gems and the ratio of full length transcripts (FL-SMN2) to transcripts lacking exon 7 (SMN2?7). Furthermore, in SMA-like mice, triptolide significantly increased SMN protein levels of brain, spinal cord and gastrocnemius muscle. Furthermore, triptolide treatment increased survival and reduced weight loss in SMA-like mice. Conclusions and implications:? Triptolide enhances SMN protein production by promoting SMN2 activation, exon 7 inclusion and increasing nuclear gems, and extends survival in SMA mice, which suggests triptolide might be a potential target for SMA therapy.

PMID: 22215052 [PubMed - in process]

Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease, which is the leading genetic cause of mortality in children. To date no effective treatment exists for SMA. The genetic basis for SMA has been well documented as a mutation in the gene for survival of motor neuron (SMN). Because there is an understanding of which gene needs to be replaced (SMN) and where it needs to be replaced (spinal motor systems), SMA is an ideal target for gene replacement via gene therapy. While a variety of animal models for SMA exist, they are either too fulminant to realistically test most gene delivery strategies, or too mild to provide a robust read out of the therapeutic effect. The field, therefore, requires a robust model with a slower symptomatic progression. A conditional knockout of SMN in neuronal cell types, giving a phenotype of functional motor defects, weight loss and reduced life expectancy partially satisfies this need (Frugier, Tiziano et al. 2000). This Cre/LoxP mediated neuron specific model presents an attractive alternative. In the present manuscript, we characterize the functional motor deficits of the model. We observed a decline in locomotor ability, as assessed by open field testing. The finer functions of motor skills such as righting reflex and grip strength were also observed to degenerate in the SMA mice. The decline in motor function that we observed here correlates with the anatomical decline in motor neurons and motor axons presented in the literature (Ferri, Melki et al. 2004). This work adds to our understanding and knowledge base of this Cre/LoxP model and provides a basis from which functional recovery, following interventions can be assessed.

Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease that affects alpha motoneurons in the spinal cord caused by homozygous deletion or specific mutations in the survival motoneuron-1 (SMN1) gene. Cell migration is critical at many stages of nervous system development; to investigate the role of SMN in cell migration, U87MG astroglioma cells were transduced with shSMN lentivectors and about 60% reduction in SMN expression was achieved. In a monolayer wound-healing assay, U87MG SMN-depleted cells exhibit reduced cell migration. In these cells, RhoA was activated and phosphorylated levels of myosin regulatory light chain (MLC), a substrate of the Rho kinase (ROCK), were found increased. The decrease in cell motility was related to activation of RhoA/Rho kinase (ROCK) signaling pathway as treatment with the ROCK inhibitor Y-27632 abrogated both the motility defects and MLC phosphorylation in SMN-depleted cells. As cell migration is regulated by continuous remodeling of the actin cytoskeleton, the actin distribution was studied in SMN-depleted cells. A shift from filamentous to monomeric (globular) actin, involving the disappearance of stress fibers, was observed. In addition, profilin I, an actin-sequestering protein showed an increased expression in SMN-depleted cells. SMN is known to physically interact with profilin, reducing its actin-sequestering activity. The present results suggest that in SMN-depleted cells, the increase in profilin I expression and the reduction in SMN inhibitory action on profilin could lead to reduced filamentous actin polymerization, thus decreasing cell motility. We propose that the alterations reported here in migratory activity in SMN-depleted cells, related to abnormal activation of RhoA/ROCK pathway and increased profilin I expression could have a role in developing nervous system by impairing normal neuron and glial cell migration and thus contributing to disease pathogenesis in SMA.

Abstract
Spinal muscular atrophy, a hereditary degenerative disorder of lower motor neurons associated with progressive muscle weakness and atrophy, is the most common genetic cause of infant mortality. It is caused by decreased levels of the "survival of motor neuron" (SMN) protein. Its inheritance pattern is autosomal recessive, resulting from mutations involving the SMN1 gene on chromosome 5q13. However, unlike many other autosomal recessive diseases, the SMN gene involves a unique structure (an inverted duplication) that presents potential therapeutic targets. Although no effective treatment for spinal muscular atrophy exists, the field of translational research in spinal muscular atrophy is active, and clinical trials are ongoing. Advances in the multidisciplinary supportive care of children with spinal muscular atrophy also offer hope for improved life expectancy and quality of life.

Abstract
Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder characterized by ?-motor neuron loss in the spinal cord anterior horn. SMA results from deletion or mutation of the Survival Motor Neuron 1 gene (SMN1) and retention of SMN2. A single nucleotide difference between SMN1 and SMN2 results in exclusion of exon 7 from the majority of SMN2 transcripts, leading to decreased SMN protein levels and development of SMA. A series of splice enhancers and silencers regulate incorporation of SMN2 exon 7; these splice motifs can be blocked with antisense oligomers (ASOs) to alter SMN2 transcript splicing. We have evaluated a morpholino oligomer against ISS-N1 (HSMN2Ex7D(-10,-29)), and delivered this morpholino (MO) to postnatal day 0 (P0) SMA pups (Smn -/-, SMN2+/+, SMN7 +/+) by intracerebroventricular (ICV) injection. Survival was increased markedly from 15 days to over 100 days. Delayed CNS MO injection has moderate efficacy, and delayed peripheral injection has mild survival advantage, suggesting that early CNS ASO administration is essential for SMA therapy consideration. ICV treatment increased full-length SMN2 transcript as well as SMN protein in neural tissue, but only minimally in peripheral tissue. Interval analysis shows a decrease in alternative splice modification over time. We suggest that CNS increases of SMN will have a major impact on SMA, and an early increase of SMN level results in correction of motor phenotypes. Last, the early introduction by intrathecal delivery of morpholino oligomers is a potential treatment for SMA patients.

Abstract
Spinal Muscular Atrophy (SMA), an autosomal recessive neuromuscular disorder, is the leading genetic cause of infant mortality. SMA is caused by the homozygous loss of Survival Motor Neuron-1 (SMN1). SMA, however, is not due to complete absence of SMN, rather a low level of functional full-length SMN is produced by a nearly identical copy gene called SMN2. Despite SMN's ubiquitous expression, motor neurons are preferentially affected by low SMN levels. Recently gene replacement strategies have shown tremendous promise in animal models of SMA. In this study, we used self-complementary Adeno Associated Virus (scAAV) expressing full-length SMN cDNA to compare two different routes of viral delivery in a severe SMA mouse model. This was accomplished by injecting scAAV9-SMN vector intravenously (IV) or intracerebroventricularly (ICV) into SMA mice. Both routes of delivery resulted in a significant increase in lifespan and weight compared to untreated mice with a subpopulation of mice surviving more than 200days. However, the ICV injected mice gained significantly more weight than their IV treated counterparts. Likewise, survival analysis showed that ICV treated mice displayed fewer early deaths than IV treated animals. Collectively, this report demonstrates that route of delivery is a crucial component of gene therapy treatment for SMA.

Abstract
BACKGROUND: Spinal muscular atrophy (SMA) is caused by degeneration of anterior horn cells of the spinal cord, which leads to progressive muscle weakness. Children with SMA type I will never be able to sit without support and usually die by the age of two years. There are no known efficacious drug treatments that influence the course of the disease. This is an update of a review first published in 2009.
OBJECTIVES: To evaluate whether drug treatment is able to slow or arrest the disease progression of SMA type I, and to assess if such therapy can be given safely. Drug treatment for SMA types II and III is the topic of a separate updated Cochrane review.
SEARCH METHODS: We searched the Cochrane Neuromuscular Disease Group Specialized Register (8 March 2011), CENTRAL (The Cochrane Library 2011, Issue 1), MEDLINE (January 1991 to February 2011), EMBASE (January 1991 to February 2011) and ISI Web of Knowledge (January 1991 to 8 March 2011). We searched the Clinical Trials Registry of the U.S. National Institute of Health (www.ClinicalTrials.gov) (8 March 2011) to identify additional trials that had not yet been published.
SELECTION CRITERIA: We sought all randomised or quasi-randomised trials that examined the efficacy of drug treatment for SMA type I. Participants had to fulfil the clinical criteria and have a deletion or mutation of the SMN1 gene (5q11.2-13.2) confirmed by genetic analysis.The primary outcome measure was time from birth until death or full time ventilation. Secondary outcome measures were development of rolling, sitting or standing within one year after the onset of treatment, and adverse events attributable to treatment during the trial period.
DATA COLLECTION AND ANALYSIS: Two authors (RW and AV) independently reviewed and extracted data from all potentially relevant trials. For included studies, pooled relative risks and standardised mean differences were to be calculated to assess treatment efficacy.
MAIN RESULTS: One small randomised controlled study comparing riluzole treatment to placebo for 10 SMA type 1 children was identified and included in the original review. No further trials were identified for the update in 2011. Regarding the primary outcome measure, three of seven children treated with riluzole were still alive at the ages of 30, 48 and 64 months, whereas all three children in the placebo group died; but the difference was not statistically significant. Regarding the secondary outcome measures, none of the children in the riluzole or placebo group developed the ability to roll, sit or stand, and no adverse effects were observed. For several reasons the overall quality of the study was low, mainly because the study was too small to detect an effect and because of baseline differences. Follow-up of the 10 included children was complete.
AUTHORS' CONCLUSIONS: No drug treatment for SMA type I has been proven to have significant efficacy.

Abstract
Motor neuron diseases (MND) such as amyotrophic lateral sclerosis and spinal muscular atrophy are devastating, progressive and ultimately fatal diseases for which there are no effective treatments. Recent evidence from systematic studies of animal models and human patients suggests that the neuromuscular junction (NMJ) is an important early target in MND, demonstrating functional and structural abnormalities in advance of pathological changes occurring in the motor neuron cell body. The ability to study pathological changes occurring at the NMJ in humans is therefore likely to be important for furthering our understanding of disease pathogenesis, and also for designing and testing new therapeutics. However, there are many practical and technical reasons why it is not possible to visualise or record from NMJs in pre- and early-symptomatic MND patients in vivo. Other approaches are therefore required. The development of stem cell technologies has opened up the possibility of creating human NMJs in vitro, using pluripotent cells generated from healthy individuals and patients with MND. This review covers historical attempts to develop mature and functional NMJs in vitro, using co-cultures of muscle and nerve from animals, and discusses how recent developments in the generation and specification of human induced pluripotent stem cells provides an opportunity to build on these previous successes to recapitulate human neuromuscular connectivity in vitro.

Abstract
Bench to bedside progress has been widely anticipated for a growing number of neurodegenerative disorders. Of these, spinal muscular atrophy (SMA) is perhaps the best poised to capitalize on advances in targeted therapeutics development over the next few years. Several laboratories have achieved compelling success in SMA animal models using sophisticated methods for targeted delivery, repair, or increased expression of the survival motor neuron protein, SMN. The clinical community is actively collaborating to identify, develop, and validate outcome measures and biomarkers in parallel with laboratory efforts. Innovative trial design and synergistic approaches to maximize proactive care in conjunction with treatment with one or more of the promising pharmacologic and biologic therapies currently in the pipeline will maximize our chances to achieve meaningful outcomes for patients. This review highlights recent promising scientific and clinical advances bringing us ever closer to effective treatment(s) for our patients with SMA.

Abstract
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease of motor neurons that causes progressive muscle weakness, paralysis, and premature death. No effective therapy is available. Research in the motor neuron field continues to grow, and recent breakthroughs have demonstrated the possibility of completely achieving rescue in animal models of spinal muscular atrophy, a genetic motor neuron disease. With adeno-associated virus (AAV) vectors, gene transfer can be achieved with systemic non-invasive injection and minimal toxicity. In the context of this success, we review gene therapy approaches for ALS, considering what has been done and the possible future directions for effective application of the latest generation of vectors for clinical translation. We focus on recent developments in the areas of RNA/antisense-mediated silencing of specific ALS causative genes like superoxide dismutase-1 and other molecular pathogenetic targets, as well as the administration of neuroprotective factors with viral vectors. We argue that gene therapy offers new opportunities to open the path for clinical progress in treating ALS.

Abstract
We report prototype development and testing of a new mobile-phone-based brain-muscle-computer interface for severely paralyzed persons, based on previous results from our group showing that humans may actively create specified power levels in two separate frequency bands of a single surface electromyography (sEMG) signal. EMG activity on the surface of a single face muscle site (auricularis superior) is recorded with a standard electrode. This analog electrical signal is imported into an Android-based mobile phone and digitized via an internal A/D converter. The digital signal is split, and then simultaneously filtered with two band-pass filters to extract total power within two separate frequency bands. The user-modulated power in each frequency band serves as two separate control channels for machine control. After signal processing, the Android phone sends commands to external devices via a Bluetooth interface. Users are trained to use the device via visually based operant conditioning, with simple cursor-to-target activities on the phone screen. The mobile-phone prototype interface is formally evaluated on a single advanced Spinal Muscle Atrophy subject, who has successfully used the interface in his home in evaluation trials and for remote control of a television. Development of this new device will not only guide future interface design for community use, but will also serve as an information technology bridge for in situ data collection to quantify human sEMG manipulation abilities for a relevant population.

Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive disorder affecting the expression or function of survival motor neuron protein (SMN) due to the homozygous deletion or rare point mutations in the survival motor neuron gene 1 (SMN1). The human genome includes a second nearly identical gene called SMN2 that is retained in SMA. SMN2 transcripts undergo alternative splicing with reduced levels of SMN. Up-regulation of SMN2 expression, modification of its splicing, or inhibition of proteolysis of the truncated protein derived from SMN2 have been discussed as potential therapeutic strategies for SMA. In this manuscript, we detail the discovery of a series of arylpiperidines as novel modulators of SMN protein. Systematic hit-to-lead efforts significantly improved potency and efficacy of the series in the primary and orthogonal assays. Structure-property relationships including microsomal stability, cell permeability, and in vivo pharmacokinetics (PK) studies were also investigated. We anticipate that a lead candidate chosen from this series may serve as a useful probe for exploring the therapeutic benefits of SMN protein up-regulation in SMA animal models and a starting point for clinical development.

Abstract
Although advances in understanding of the pathogenesis of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) have suggested attractive treatment strategies, delivery of agents to motor neurons embedded within the spinal cord is problematic. We have designed a strategy based on the specificity of botulinum toxin, to direct entry of viral vectors carrying candidate therapeutic genes into motor neurons. We have engineered and expressed fusion proteins consisting of the binding domain of botulinum toxin type A fused to streptavidin (SAv). This fusion protein will direct biotinylated viral vectors carrying therapeutic genes into motor nerve terminals where they can enter the acidified endosomal compartments, be released and undergo retrograde transport, to deliver the genes to motor neurons. Both ends of the fusion proteins are shown to be functionally intact. The binding domain end binds to mammalian nerve terminals at neuromuscular junctions, ganglioside GT1b (a target of botulinum toxin), and a variety of neuronal cells including primary chick embryo motor neurons, N2A neuroblastoma cells, NG108-15 cells, but not to NG CR72 cells, which lack complex gangliosides. The streptavidin end binds to biotin, and to a biotinylated Alexa 488 fluorescent tag. Further studies are in progress to evaluate the delivery of genes to motor neurons in vivo, by the use of biotinylated viral vectors.

Abstract
BACKGROUND: Multiple lines of evidence have suggested that valproic acid (VPA) might benefit patients with spinal muscular atrophy (SMA). The SMA CARNIVAL TRIAL was a two part prospective trial to evaluate oral VPA and L-carnitine in SMA children. Part 1 targeted non-ambulatory children ages 2-8 in a 12 month cross over design. We report here Part 2, a twelve month prospective, open-label trial of VPA and L-carnitine in ambulatory SMA children.
METHODS: This study involved 33 genetically proven type 3 SMA subjects ages 3-17 years. Subjects underwent two baseline assessments over 4-6 weeks and then were placed on VPA and L-carnitine for 12 months. Assessments were performed at baseline, 3, 6 and 12 months. Primary outcomes included safety, adverse events and the change at 6 and 12 months in motor function assessed using the Modified Hammersmith Functional Motor Scale Extend (MHFMS-Extend), timed motor tests and fine motor modules. Secondary outcomes included changes in ulnar compound muscle action potential amplitudes (CMAP), handheld dynamometry, pulmonary function, and Pediatric Quality of Life Inventory scores.
RESULTS: Twenty-eight subjects completed the study. VPA and carnitine were generally well tolerated. Although adverse events occurred in 85% of subjects, they were usually mild and transient. Weight gain of 20% above body weight occurred in 17% of subjects. There was no significant change in any primary outcome at six or 12 months. Some pulmonary function measures showed improvement at one year as expected with normal growth. CMAP significantly improved suggesting a modest biologic effect not clinically meaningful.
CONCLUSIONS: This study, coupled with the CARNIVAL Part 1 study, indicate that VPA is not effective in improving strength or function in SMA children. The outcomes used in this study are feasible and reliable, and can be employed in future trials in SMA. TRIAL REGSITRATION: Clinicaltrials.gov NCT00227266.

Abstract
Life-sustaining treatment is sometimes withdrawn or withheld from critically ill newborn infants with poor prognosis. Guidelines relating to such decisions place emphasis on the best interests of the infant. However, in practice, parental views and parental interests are often taken into consideration. In this paper I draw on the example of newborn infants with severe muscle weakness (for example spinal muscular atrophy). I provide two arguments that parental interests should be given some weight in decisions about treatment, and that they should be given somewhat more weight in decisions about newborns than for older children. Firstly, the interests of the infant and of parents intersect, and are hard to separate. Parents' views about treatment may be relevant to an assessment of the infant's interests, and they may also affect those interests. Secondly, the interests of the infant in her future are relatively reduced by her developmental immaturity. In some situations parents' welfare interests outweigh those of the infant. However, I argue that this would not justify treatment limitation except in the setting of severe impairment.

Abstract
Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder that causes degeneration of ?-motor neurons. Frequently, muscle weakness is very severe causing affected infants to die before reaching two years of age, but mild forms of the disease can be characterized by relatively static muscle weakness for many years. SMA is caused by recessive mutations of the SMN1 gene, but all patients retain at least one copy of SMN2, a similar gene capable of producing low levels of full-length SMN protein. No treatments currently exist for SMA patients, but the identification of therapeutic targets and the development of suitable animal models for preclinical testing have resulted in increased drug development efforts in the past ten years. Here, we review the current status of many of these programs, including those designed to activate SMN2 gene expression, modulate splicing of SMN2 preRNAs, stabilize SMN protein, replace SMN1, provide neuroprotective support, and transplant neural cells.

Abstract
Spinal Muscular Atrophy, an autosomal recessive neuromuscular disorder, is the leading genetic cause of infant mortality. SMA is caused by the homozygous loss of Survival Motor Neuron-1 (SMN1). In humans, a nearly identical copy gene is present, SMN2. SMN2 is retained in all SMA patients, and encodes the same protein as SMN1. However, SMN1 and SMN2 differ by a silent C to T transition at the 5' end of exon 7, causing alternative splicing of SMN2 transcripts and low levels of full-length SMN. SMA is monogenic and therefore well suited for gene replacement strategies. Recently, self-complementary AAV vectors have been used to deliver the SMN cDNA to an animal model of disease, the SMN?7 mouse. In this study we examine a severe model of SMA to determine whether gene replacement is viable in a model in which disease development begins in utero. Utilizing two delivery paradigms, intracerebroventricular injections and intravenous injections, we delivered scAAV9-SMN and demonstrated a 2-4 fold increase in survival, in addition to improving many of the phenotypic parameters of the model. This represents the longest extension in survival for this severe model for any therapeutic intervention and suggests that post-symptomatic treatment of SMA may lead to significant improvement of disease severity.

Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss of survival motor neuron-1 (SMN1). A nearly identical copy gene, SMN2, is present in all SMA patients. Although the SMN2 coding sequence has the potential to produce full-length SMN, nearly 90% of SMN2-derived transcripts are alternatively spliced and encode a truncated protein. SMN2, however, is an excellent therapeutic target. Previously, we developed antisense-based oligonucleotides (bifunctional RNAs) that specifically recruit SR/SR-like splicing factors and target a negative regulator of SMN2 exon-7 inclusion within intron-6. As a means to optimize the antisense sequence of the bifunctional RNAs, we chose to target a potent intronic repressor downstream of SMN2 exon 7, called intronic splicing silencer N1 (ISS-N1). We developed RNAs that specifically target ISS-N1 and concurrently recruit the modular SR proteins SF2/ASF or hTra2?1. RNAs were directly injected in the brains of SMA mice. Bifunctional RNA injections were able to elicit robust induction of SMN protein in the brain and spinal column of neonatal SMA mice. Importantly, hTra2?1-ISS-N1 and SF2/ASF-ISS-N1 bifunctional RNAs significantly extended lifespan and increased weight in the SMN?7 mice. This technology has direct implications for SMA therapy and provides similar therapeutic strategies for other diseases caused by aberrant splicing.

Abstract
Activity-induced weakness was reported in multifocal motor neuropathy (MMN) and chronic inflammatory demyelinating polyneuropathy (CIDP). This was attributed to activity-dependent conduction block (CB) arising in demyelinated axons. It is not known if activity-induced weakness is common, nor if it is specific for MMN and CIDP. We, therefore, carried out an investigation by questionnaire in 64 MMN patients, 52 CIDP patients, 48 progressive spinal muscular atrophy (PSMA) patients, and 30 normal subjects. Subjects were asked if they experienced an increase in weakness when performing 10 common tasks. The percentage of tasks causing activity-induced weakness was higher in the patient groups than in the normal subjects (p < 0.001). The risk of activity-induced weakness exceeding that in normal subjects was sixfold higher for each patient group when adjusted for sex, age, and a fatigue score. With further adjustment for scores of weakness and axon loss, no significant differences were found between the patient groups. In conclusion, activity-induced weakness is frequently reported in MMN and CIDP. It is, however, not specific for these neuropathies as PSMA patients reported it to the same extent.

Abstract
The aim of this study was to demonstrate demographics of 39 consecutive Spinal Muscular Atrophy (SMA) type 1 patients diagnosed genetically in a tertiary center between June 2006 and June 2009. There was history of consanguineous marriage in 27 (69%) patients. The average patient lifespan was 251 days (30-726 days). The average patient age at diagnosis was 129 days (33-297 days). A statistically significant correlation was found between the age at diagnosis and the lifespan (p?=?0.00). No significant correlation was found between the time spent in intensive care and the lifespan (p?=?0.43). Routine physical therapy was found to have no significant impact on the lifespan average (p?=?0.17). The cause of death in all of our patients was respiratory issues. Genetic counseling was given to 35 families. A second child with SMA was born in three out of the 14 families who declined prenatal diagnosis. Conclusion: A national program is needed in Turkey for SMA prevention and creation of expert teams for the management of these patients.

Abstract
Invertebrate genetic models with their tractable neuromuscular systems are effective vehicles for the study of human nerve and muscle disorders. This is exemplified by insights made into spinal muscular atrophy (SMA) using the fruit fly Drosophila melanogaster and the nematode worm Caenorhabditis elegans. For speed and economy, these invertebrates offer convenient, whole-organism platforms for genetic screening as well as RNA interference (RNAi) and chemical library screens, permitting the rapid testing of hypotheses related to disease mechanisms and the exploration of new therapeutic routes and drug candidates. Here, we discuss recent developments encompassing synaptic physiology, RNA processing, and screening of compound and genome-scale RNAi libraries, showcasing the importance of invertebrate SMA models. Editor's suggested further reading in BioEssays: SMN and Gemins: 'We are family" ... or are we? Abstract.

Abstract
In the June issue of Experimental Neurology, Nizzardo and colleagues demonstrate that the beta-lactam antibiotic ceftriaxone is neuroprotective in a mouse model of spinal muscular atrophy. Here I review their main findings and the relevance to previous and future work on motor neuron disorders and for developing therapeutic strategies.

Abstract
Despite the protective role that blood brain barrier plays in shielding the brain, it limits the access to the central nervous system (CNS) which most often results in failure of potential therapeutics designed for neurodegenerative disorders (1,2). Neurodegenerative diseases such as Spinal Muscular Atrophy (SMA), in which the lower motor neurons are affected, can benefit greatly from introducing the therapeutic agents into the CNS. The purpose of this video is to demonstrate two different injection paradigms to deliver therapeutic materials into neonatal mice soon after birth. One of these methods is injecting directly into cerebral lateral ventricles (Intracerebroventricular) which results in delivery of materials into the CNS through the cerebrospinal fluid (3,4). The second method is a temporal vein injection (intravenous) that can introduce different therapeutics into the circulatory system, leading to systemic delivery including the CNS (5). Widespread transduction of the CNS is achievable if an appropriate viral vector and viral serotype is utilized. Visualization and utilization of the temporal vein for injection is feasible up to postnatal day 6. However, if the delivered material is intended to reach the CNS, these injections should take place while the blood brain barrier is more permeable due to its immature status, preferably prior to postnatal day 2. The fully developed blood brain barrier greatly limits the effectiveness of intravenous delivery. Both delivery systems are simple and effective once the surgical aptitude is achieved. They do not require any extensive surgical devices and can be performed by a single person. However, these techniques are not without challenges. The small size of postnatal day 2 pups and the subsequent small target areas can make the injections difficult to perform and initially challenging to replicate.

Abstract
Induced pluripotent stem (iPS) cell technology has enormous potential to advance medical therapy by personalizing regenerative medicine and creating novel human disease models for research and therapeutic testing. Before this technology is broadly used in the clinic, we must realistically evaluate its disease modeling and therapeutic potential. Recent advances including the use of iPS cells to successfully model spinal muscular atrophy in vitro, as well as new techniques in generating iPS cells with recombinant proteins have accelerated the prospects of iPS cells for clinical use in regenerative therapy. This review explores the development and limitations of iPS cell technology, presents a critical comparison of iPS cells and embryonic stem cells, and discusses potential clinical applications and future research directions.

Abstract
Spinal muscular atrophy (SMA) is a motor neuron disease and the leading genetic cause of infant mortality; it results from loss-of-function mutations in the survival motor neuron 1 (SMN1) gene. Humans have a paralogue, SMN2, whose exon 7 is predominantly skipped, but the limited amount of functional, full-length SMN protein expressed from SMN2 cannot fully compensate for a lack of SMN1. SMN is important for the biogenesis of spliceosomal small nuclear ribonucleoprotein particles, but downstream splicing targets involved in pathogenesis remain elusive. There is no effective SMA treatment, but SMN restoration in spinal cord motor neurons is thought to be necessary and sufficient. Non-central nervous system (CNS) pathologies, including cardiovascular defects, were recently reported in severe SMA mouse models and patients, reflecting autonomic dysfunction or direct effects in cardiac tissues. Here we compared systemic versus CNS restoration of SMN in a severe mouse model. We used an antisense oligonucleotide (ASO), ASO-10-27, that effectively corrects SMN2 splicing and restores SMN expression in motor neurons after intracerebroventricular injection. Systemic administration of ASO-10-27 to neonates robustly rescued severe SMA mice, much more effectively than intracerebroventricular administration; subcutaneous injections extended the median lifespan by 25 fold. Furthermore, neonatal SMA mice had decreased hepatic Igfals expression, leading to a pronounced reduction in circulating insulin-like growth factor 1 (IGF1), and ASO-10-27 treatment restored IGF1 to normal levels. These results suggest that the liver is important in SMA pathogenesis, underscoring the importance of SMN in peripheral tissues, and demonstrate the efficacy of a promising drug candidate.

Abstract
Spinal muscular atrophy (SMA), a motoneuron disease caused by a deficiency of the Survival of Motor Neuron (SMN) protein, is characterized by motoneuron loss and muscle weakness. It remains unclear whether widespread loss of neuromuscular junctions (NMJs) is involved in SMA pathogenesis. We undertook a systematic examination of NMJ innervation patterns in >20 muscles in the SMN?7 SMA mouse model. We found that severe denervation (<50% fully innervated endplates) occurs selectively in many vulnerable axial muscles and several appendicular muscles at the disease end stage. Since these vulnerable muscles were located throughout the body, and were comprised of varying muscle fiber types, it is unlikely that muscle location or fiber type determines susceptibility to denervation. Furthermore, we found a similar extent of neurofilament accumulation at NMJs in both vulnerable and resistant muscles before the onset of denervation, suggesting that neurofilament accumulation does not predict subsequent NMJ denervation. Since vulnerable muscles were initially innervated, but later denervated, loss of innervation in SMA may be attributed to defects in synapse maintenance. Finally, we found that denervation was amendable by trichostatin A (TSA) treatment, which increased innervation in clinically-relevant muscles in TSA-treated SMN?7 mice. Our findings suggest that neuromuscular denervation in vulnerable muscles is a widespread pathology in SMA, and can serve as a preparation for elucidating the biological basis of synapse loss, and for evaluating therapeutic efficacy.

Abstract
The development of effective therapies for neuromuscular disorders such as Duchenne muscular dystrophy (DMD) is hampered by considerable challenges: skeletal muscle is the most abundant tissue in the body, and many neuromuscular disorders are multisystemic conditions. However, despite these barriers there has recently been substantial progress in the search for novel treatments. In particular, the use of antisense oligonucleotides, which are designed to target RNA and modulate pre-mRNA splicing to restore functional protein isoforms or directly inhibit the toxic effects of pathogenic RNAs, offers great promise and these approaches are now being tested in the clinic. Here, we review recent advances in the development of such antisense oligonucleotides and other promising novel approaches, including the induction of readthrough nonsense mutations.

Abstract
Antisense oligomers initially showed promise as compounds to modify gene expression, primarily through RNaseH induced degradation of the target transcript. Expansion of the field has led to new chemistries capable of invoking different mechanisms, including suppression of protein synthesis by translational blockade and gene silencing using short interfering RNAs. It is now apparent that the majority of the eukaryotic genome is transcribed and non-protein coding RNAs have been implicated in the regulation of gene expression at many levels. This review considers potential therapeutic applications of antisense oligomers to modify gene expression, primarily by interfering with the process of exon recognition and intron removal during gene transcript splicing. While suppression of gene expression will be necessary to address some conditions, it is likely that antisense oligomer splice modification will have extensive clinical application. Pre-mRNA splicing is a tightly co-ordinated, multifactorial process that can be disrupted by antisense oligomers in a highly specific manner to suppress aberrant splicing, remove exons to by-pass nonsense or frame-shifting mutations or influence exon selection to alter spliceoform ratios. Manipulation of splicing patterns has been applied to a diverse range of conditions, including b-thalassemia, Duchenne muscular dystrophy, spinal muscular atrophy and certain cancers. Alternative exon usage has been identified as a major mechanism for generating diversity from a limited repertoire of genes in higher eukaryotes. Considering that the majority of all human primary gene transcripts are reportedly alternatively spliced, intervention at the level of pre-mRNA processing is likely to become increasingly significant in the fight against genetic and acquired disorders.

Abstract
Several types of motorneuron diseases are linked to neurotoxic mutant proteins. These acquire aberrant conformations (misfolding) that trigger deleterious downstream events responsible for neuronal dysfunction and degeneration. The pharmacological removal of misfolded proteins might thus be useful in these diseases. We utilized a peculiar motorneuronal disease model, spinobulbar muscular atrophy (SBMA), in which the neurotoxicity of the protein involved, the mutant androgen receptor (ARpolyQ), can be modulated by its ligand testosterone (T). 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) has already been proven to exert beneficial action in SBMA. Here we demonstrated that 17-AAG exerts its pro-degradative activity on mutant ARpolyQ without impacting on proteasome functions. 17-AAG removes ARpolyQ misfolded species and aggregates by activating the autophagic system. We next analyzed the 17-AAG effects on two proteins (SOD1 and TDP-43) involved in related motorneuronal diseases, such as amyotrophic lateral sclerosis (ALS). In these models 17-AAG was unable to counteract protein aggregation.

Abstract
The relationships between the Expanded Hammersmith Functional Motor Scale (HFMSE) and genotype and motor and respiratory outcomes were examined in patients with spinal muscular atrophy types II and III (n = 70). The correlation between the HFMSE and Gross Motor Function Measure was r = 0.98. Correlations between HFMSE and forced vital capacity (percentage of predicted normal) (n = 56) and a functional rating (n = 57) were r = 0.87 and r = 0.92, respectively. Correlations with strength were as follows: knee extension, r = 0.74 (n = 60); elbow flexion, r = 0.77 (n = 61); and knee flexion, r = 0.74 (n = 58). The HFMSE differentiated patients by SMN2 copy number (P = .0007); bi-level positive airway pressure use, <8 versus ?8 hours/day (P < .0001); ambulatory status (P < .0001); and spinal muscular atrophy type (P < .0001). The HFMSE demonstrates significant associations with established measures of function, strength, and genotype, and discriminates patients based on function, diagnostic category, and bi-level positive airway pressure need. Time of administration averaged 12 minutes. The HFMSE is a valid, time-efficient outcome measure for clinical trials in spinal muscular atrophy types II and III.

Abstract
ABSTRACT: Five years after their initial derivation from mouse somatic cells, induced pluripotent stem (iPS) cells are an important tool for the study of neurological diseases. By offering an unlimited source of patient-specific disease-relevant neuronal and glial cells, iPS cell-based disease models hold enormous promise for identification of disease mechanisms, discovery of molecular targets and development of phenotypic screens for drug discovery. The present review focuses on the recent advancements in modeling neurological disorders, including the demonstration of disease-specific phenotypes in iPS cell-derived neurons generated from patients with spinal muscular atrophy, familial dysautonomia, Rett syndrome, schizophrenia and Parkinson disease. The ability of this approach to detect treatment effects from known therapeutic compounds has also been demonstrated, providing proof of principle for the use of iPS cell-derived cells in drug discovery.

Abstract
OBJECTIVE: To identify the prevalence and risk factors of feeding and swallowing problems in patients with type II and type III spinal muscular atrophy (SMA). STUDY DESIGN: Cross-sectional data from 108 genetically confirmed patients with SMA (age range, 3-45 years; 60 with type II and 48 with type III) were analyzed. The questionnaire survey included demographic data, current motor function and respiratory status, feeding and swallowing difficulties, and consequences. The risk factors were analyzed via logistic regression. RESULTS: The 3 most common feeding and swallowing difficulties in patients with type II and III SMA were choking (30.6%), difficulty conveying food to the mouth (20.4%), and difficulty chewing (20.4%). Current motor function status was an independent risk factor for feeding and swallowing difficulties (sitters vs walkers: OR, 7.59; 95% CI, 1.22-47.46). All 4 nonsitters (ie, patients with type II SMA who had lost their sitting ability) had feeding and swallowing difficulties. Patients with feeding and swallowing difficulties had significantly higher rates of underweight and aspiration pneumonia than those without these problems. CONCLUSION: Patients with type II and III SMA have a high prevalence of risk factors for feeding and swallowing difficulties, suggesting that an individualized treatment plan should depend on current motor function status.

Abstract
Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder that is the leading genetic cause of infantile death. SMA is caused by homozygous deletion or mutation of the survival of motor neuron 1 gene (SMN1). The SMN2 gene is nearly identical to SMN1, however is alternatively spliced. The close relationship to SMN1 results in SMN2 being a very power genetic modifier of SMA disease severity and a target for therapies. We sought to identify the regulatory role individual HDAC proteins use to control expression of full length protein from the SMN2 genes. We used quantitative PCR to determine the effects shRNA silencing of individual HDACs on the steady state levels of a SMN2-luciferase reporter transcripts. We determined that reduction of individual HDAC proteins was sufficient to increase SMN protein levels in a transgenic reporter system. Knockdown of class I HDAC proteins preferentially activated the reporter by increased promoter transcription. Silencing of class II HDAC proteins maintained transcriptional activity; however silencing of HDAC 5 and 6 also appeared to enhance inclusion of an alternatively spliced exon. This work highlights HDAC proteins 2 and 6 as excellent investigative targets. These data are important to the basic understanding of SMN expression regulation and the refinements of current therapeutic compounds as well as the development of novel SMA therapeutics.

Abstract
The derivation of pluripotent stem cells from somatic tissues has provided researchers with a source of patient-specific stem cells. The potential applications of this technology are truly momentous, and include cellular modeling of disease processes, drug discovery, and cell-based therapy. Here, we review the use of induced pluripotent stem cells (iPSCs) to study CNS disease. Since the iPSC field is still in its infancy, we also discuss some of the challenges that will need to be overcome before the potential of this technology to study and to treat neurological and psychiatric disorders can be fully harnessed.

Abstract
Motor neuron degeneration leading to muscle atrophy and death is a pathological hallmark of disorders, such as amyotrophic lateral sclerosis or spinal muscular atrophy. No effective treatment is available for these devastating diseases. At present, cell-based therapies targeting motor neuron replacement, support, or as a vehicle for the delivery of neuroprotective molecules are being investigated. Although many challenges and questions remain, the beneficial effects observed following transplantation therapy in animal models of motor neuron disease has sparked hope and a number of clinical trials. Here, we provide a comprehensive review of cell-based therapeutics for motor neuron disorders, with a particular emphasis on amyotrophic lateral sclerosis.

Abstract
Over the past 20 years, stem cell technologies have become an increasingly attractive option to investigate and treat neurodegenerative diseases. In the current review, we discuss the process of extending basic stem cell research into translational therapies for patients suffering from neurodegenerative diseases. We begin with a discussion of the burden of these diseases on society, emphasizing the need for increased attention toward advancing stem cell therapies. We then explain the various types of stem cells utilized in neurodegenerative disease research, and outline important issues to consider in the transition of stem cell therapy from bench to bedside. Finally, we detail the current progress regarding the applications of stem cell therapies to specific neurodegenerative diseases, focusing on Parkinson disease, Huntington disease, Alzheimer disease, amyotrophic lateral sclerosis, and spinal muscular atrophy. With a greater understanding of the capacity of stem cell technologies, there is growing public hope that stem cell therapies will continue to progress into realistic and efficacious treatments for neurodegenerative diseases. Ann Neurol 2011;70: 353-361.

Abstract
PURPOSE: The purpose of this study is to determine the use of orthopaedic and assistive devices for Spinal muscular atrophy (SMA) patients, following a survey of 194 patients.
METHOD: The use of wheelchairs, corsets and orthoses was evaluated in 194 SMA patients whose mean age was 12.6 (SD 7.2, 0.7-41.1). There were 14 patients with SMA type Ib (age range 1.7-36.9), 133 with type II (age range 0.7-37.7), 42 with type IIIa (age range 3.2-41.1) and 5 with type IIIb (age range 8.0-20.0).
RESULTS: One hundred and sixteen patients (60%) had powered and 29 patients (15%) manual wheelchairs. Nineteen patients (10%) used long leg orthoses. Ten patients (5%) used swivel walkers and 26 (13%) had standing frames. Twenty-six patients (13%) received lower leg orthoses because of foot deformities. Eight patients (4%) used night splints for the lower limbs. One hundred and fifteen patients (59%) were fitted with corsets because of progressive scoliosis.
CONCLUSION: This is the first study about the provision of orthopaedic and assistive devices in a large group of SMA patients. Following the results of this survey we can optimise the strategy of providing orthoses and assistive devices for SMA patients and better adapt them to the patient's individual needs.

Abstract
Autosomal recessive proximal spinal muscular atrophy is caused by deletions in the survival of motor neuron (SMN1) gene, while autoimmune myasthenia gravis is an acquired disorder. An association between these two diseases has not been reported. Our patient with intermediate spinal muscular atrophy (SMA type II) did not need alimentary or respiratory aid until age 51 when he suddenly developed bulbar weakness and respiratory insufficiency. Seropositive myasthenia gravis was confirmed and the corresponding symptoms resolved on treatment.

PURPOSE OF REVIEW: The aim is to review the most relevant findings published during the last year concerning clinical, genetic, pathogenic, and therapeutic advances in motor neuron disease, neuropathies, and neuromuscular junction disorders. RECENT FINDINGS: Studies on animal and cell models have improved the understanding of how mutated survival motor neuron protein in spinal muscular atrophy governs the pathogenetic processes. New phenotypes of SOD1 mutations have been described. Moreover, animal models enhanced the insight into the pathogenetic background of sporadic and familial amyotrophic lateral sclerosis. Novel treatment options for motor neuron disease have been described in humans and animal models. Considerable progress has been achieved also in elucidating the genetic background of many forms of inherited neuropathies and high clinical and genetic heterogeneity has been demonstrated. Mutations in MuSK and GFTP1 have been shown to cause new types of congenital myasthenic syndromes. A third type of autoantibodies (Lrp4) has been detected to cause myasthenia gravis. SUMMARY: Advances in the clinical and genetic characterization of motor neuron diseases, neuropathies, and neuromuscular transmission defects have important implications on the fundamental understanding, diagnosis, and management of these disorders. Identification of crucial steps of the pathogenetic process may provide the basis for the development of novel therapeutic strategies.

Adeno-associated virus type 9 (AAV9) is a powerful tool for delivering genes throughout the central nervous system (CNS) following intravenous injection. Preclinical results in pediatric models of spinal muscular atrophy (SMA) and lysosomal storage disorders provide a compelling case for advancing AAV9 to the clinic. An important translational step is to demonstrate efficient CNS targeting in large animals at various ages. In the present study, we tested systemically injected AAV9 in cynomolgus macaques, administered at birth through 3 years of age for targeting CNS and peripheral tissues. We show that AAV9 was efficient at crossing the blood-brain barrier (BBB) at all time points investigated. Transgene expression was detected primarily in glial cells throughout the brain, dorsal root ganglia neurons and motor neurons within the spinal cord, providing confidence for translation to SMA patients. Systemic injection also efficiently targeted skeletal muscle and peripheral organs. To specifically target the CNS, we explored AAV9 delivery to cerebrospinal fluid (CSF). CSF injection efficiently targeted motor neurons, and restricted gene expression to the CNS, providing an alternate delivery route and potentially lower manufacturing requirements for older, larger patients. Our findings support the use of AAV9 for gene transfer to the CNS for disorders in pediatric populations.

Spinal muscular atrophy (SMA) is a common neuromuscular disorder in humans. In fact, it is the most frequently inherited cause of infant mortality, being the result of mutations in the survival of motor neuron 1 (SMN1) gene that reduce levels of SMN protein. Restoring levels of SMN protein in individuals with SMA is perceived to be a viable therapeutic option, but the efficacy of such a strategy once symptoms are apparent has not been determined. We have generated mice harboring an inducible Smn rescue allele and used them in a model of SMA to investigate the effects of turning on SMN expression at different time points during the course of the disease. Restoring SMN protein even after disease onset was sufficient to reverse neuromuscular pathology and effect robust rescue of the SMA phenotype. Importantly, our findings also indicated that there was a therapeutic window of opportunity from P4 through P8 defined by the extent of neuromuscular synapse pathology and the ability of motor neurons to respond to SMN induction, following which restoration of the protein to the organism failed to produce therapeutic benefit. Nevertheless, our results suggest that even in severe SMA, timely reinstatement of the SMN protein may halt the progression of the disease and serve as an effective postsymptomatic treatment.

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease that is characterized by the loss of motor neurons, resulting in progressive muscle atrophy. It is caused by the loss of functional survival motor neuron (SMN) protein due to mutations or deletion in the SMN1 gene. A potential treatment strategy for SMA is to upregulate levels of SMN protein. Several agents that activate STAT5 in human and mouse cell lines enhance SMN expression from the SMN2 gene and can compensate, at least in part, for the loss of production of a functional protein from SMN1. Here, we have shown that prolactin (PRL) increases SMN levels via activation of the STAT5 pathway. PRL increased SMN mRNA and protein levels in cultured human and mouse neuronal cells. Administration of STAT5-specific siRNA blocked the effects of PRL, indicating that the PRL-induced transcriptional upregulation of the SMN-encoding gene was mediated by activation of STAT5. Furthermore, systemic administration of PRL to WT mice induced SMN expression in the brain and spinal cord. Critically, PRL treatment increased SMN levels, improved motor function, and enhanced survival in a mouse model of severe SMA. Our results confirm earlier work suggesting STAT5 pathway activators as potential therapeutic compounds for the treatment of SMA and identify PRL as one such promising agent.

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease that predominantly affects motor neurons, resulting in progressive muscular atrophy and weakness. SMA arises due to insufficient survival motor neuron (SMN) protein levels as a result of homozygous disruption of the SMN1 gene. SMN upregulation is a promising and potent treatment strategy for this currently incurable condition. In this issue of the JCI, two independent research groups report novel observations in mouse models of severe SMA that provide hope that this approach will afford meaningful benefit to individuals with SMA.

Stem cell-derived motor neurons (MNs) are increasingly utilized for modeling disease in vitro and for developing cellular replacement strategies for spinal cord injury and diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Human embryonic stem cell (hESC) differentiation into MNs, which involves retinoic acid (RA) and activation of the sonic hedgehog (SHH) pathway is inefficient and requires up to 60 days to develop MNs with electrophysiological properties. This prolonged differentiation process has hampered the use of hESCs, in particular for high-throughput screening. We evaluated the MN gene expression profile of RA/SHH-differentiated hESCs to identify rate-limiting factors involved in MN development. Based on this analysis, we developed an adenoviral gene delivery system encoding for MN inducing transcription factors: neurogenin 2 (Ngn2), islet-1 (Isl-1), and LIM/homeobox protein 3 (Lhx3). Strikingly, delivery of these factors induced functional MNs with mature electrophysiological properties, 11-days after gene delivery, with >60-70% efficiency from hESCs and human induced pluripotent stem cells (hiPSCs). This directed programming approach significantly reduces the time required to generate electrophysiologically-active MNs by approximately 30 days in comparison to conventional differentiation techniques. Our results further exemplify the potential to use transcriptional coding for rapid and efficient production of defined cell types from hESCs and hiPSCs.

Any structural brain lesion can provoke epilepsy, although onset and progression of seizures as well as response to antiepileptic drug (AED) treatment remain difficult to predict in each patient. Tremendous work has focused on the development of new AED compounds with the intention to treat seizures. However, these efforts have not yet discovered a "magic bullet" that cures epilepsy in every patient or modifies disease progression. With the "methylation hypothesis" we propose that epigenetic mechanisms play a pivotal role in epileptogenesis in patients with structural lesions. "Epigenetics" is defined as information that is heritable during cell division other than the DNA sequence itself, that is, DNA methylation or histone tail modifications, which can produce lasting alterations in chromatin structure and gene expression. They are increasingly recognized as fundamental regulatory processes in central nervous system development, synaptic plasticity, and memory, and also play a role in neurologic disorders such as schizophrenia and spinal muscular atrophy. The methylation hypothesis suggests that seizures by themselves can induce epigenetic chromatin modifications, thereby aggravating the epileptogenic condition. The impact of the methylation hypothesis for new-onset epilepsy will be discussed. Unravelling of epigenetic pathomechanisms will also open new strategies to identify molecular targets for pharmacologic treatment in epilepsies.

STUDY DESIGN.: Retrospective analysis of patients with spinal muscular atrophy (SMA) treated with growing rod (GR) instrumentation for scoliosis. OBJECTIVE.: To evaluate structural effectiveness, complications, and length of hospital stay associated with GRs for scoliosis in SMA and to compare values with those of infantile and juvenile idiopathic scoliosis (IIS/JIS). SUMMARY OF BACKGROUND DATA.: Most studies evaluate GR effectiveness in all patients. We specifically examined SMA and IIS/JIS. METHODS.: We searched a multicenter database and found 15 patients with SMA and scoliosis treated with GRs for 54 ± 33 months. Radiographic measurements, complications, and hospital stay durations were compared with those of 80 GR patients with IIS/JIS observed for 43 ± 31 months. Measures of rib collapse, including T6:T10 mean rib-vertebral angle and T6:T12 thoracic width, were compared. Student t test was used to compare SMA and IIS/JIS values (significance level, P = 0.05). RESULTS.: Primary radiographic measurements in patients with SMA improved from preoperative to latest follow-up as follows: curve, 89° ± 19° to 55° ± 17°; pelvic obliquity, 31° ± 14° to 11° ± 10°; space-available-for-lung ratio, 0.86 ± 0.15 to 0.94 ± 0.21; and T1-S1 length grew 8.7 ± 3.2 cm. Rib collapse continued despite GR treatment in SMA but not in IIS/JIS. Hospital stays were longer for SMA than for IIS/JIS for lengthening procedures (P = 0.01) and trended to be longer for initial surgery (P = 0.08) and final fusion (P = 0.06). Patients with SMA and IIS/JIS experienced, respectively, 0.5 and 1.1 major complications per patient (P = 0.02). CONCLUSION:: GRs improve trunk height and the space-available-for-lung ratio while controlling curve and pelvic obliquity in young patients with SMA with severe scoliosis, but they do not halt rib collapse. For patients with SMA, hospital stays were longer than those for patients with IIS/JIS, whereas the rate of major complications was lower.

Spinal muscular atrophy (SMA) is a progressive pediatric neuromuscular disease. Because disease severity is related to survival motor neuron (SMN) protein levels, increasing SMN production from the SMN2 gene has been a major SMA drug-discovery strategy. Cell-based assays using neuronal cell lines and cells from SMA patients have identified compounds that can increase SMN protein expression. Our experience of using such an assay signaled potential risks to be avoided through the use of appropriate secondary assays. In addition to the 'SMN2' approach, compensating for decreased SMN protein or neuroprotection are also potential SMA drug-discovery strategies. SMA clinical trials are now a reality; however, trial design in a slowly progressing rare disease such as SMA will present an interesting future challenge.

Spinal muscular atrophy (SMA), which is caused by inactivating mutations in the survival motor neuron 1 (SMN1) gene, is characterized by loss of lower motor neurons in the spinal cord. The gene encoding SMN is very highly conserved in evolution, allowing the disease to be modeled in a range of species. The similarities in anatomy and physiology to the human neuromuscular system, coupled with the ease of genetic manipulation, make the mouse the most suitable model for exploring the basic pathogenesis of motor neuron loss and for testing potential treatments. Therapies that increase SMN levels, either through direct viral delivery or by enhancing full-length SMN protein expression from the SMN1 paralog, SMN2, are approaching the translational stage of development. It is therefore timely to consider the role of mouse models in addressing aspects of disease pathogenesis that are most relevant to SMA therapy. Here, we review evidence suggesting that the apparent selective vulnerability of motor neurons to SMN deficiency is relative rather than absolute, signifying that therapies will need to be delivered systemically. We also consider evidence from mouse models suggesting that SMN has its predominant action on the neuromuscular system in early postnatal life, during a discrete phase of development. Data from these experiments suggest that the timing of therapy to increase SMN levels might be crucial. The extent to which SMN is required for the maintenance of motor neurons in later life and whether augmenting its levels could treat degenerative motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), requires further exploration.

Introduction: The test-retest reliability of the Modified Hammersmith Functional Motor Scale (MHFMS) in children with spinal muscular atrophy (SMA) ?30 months of age was assessed. The age at which typically developing children (TD) achieve maximum MHFMS scores was also studied. Methods: Twenty-two children with SMA type II [mean age (SD) = 20 (5) months, range 9-30 months) were tested twice using the MHFMS. Twenty-five TD children [mean age (SD) = 18 (7) months, range 9-30 months) were tested once. Results: The average difference between MHFMS scores for SMA children was 0.18 [first assessment: mean (SD) = 12.8 (9.8); second assessment: mean (SD) = 13.0 (8.8)]. Reliability was excellent (ICC(1,3) = 0.96, SEM 1.86). TD participants had MHFMS scores ranging from 36 to 40 [mean (SD) = 39.2 (1.2)] and achieved maximum test scores at 12 months of age. Discussion: MHFMS scores in young children with SMA type II showed excellent test-retest stability. This suggests that the MHFMS can be used reliably in this younger population for clinical trials and follow-up. Muscle Nerve, 2011.

The motor neuron disease spinal muscular atrophy (SMA) results from mutations that lead to low levels of the ubiquitously expressed protein survival of motor neuron (SMN). An ever-increasing collection of data suggests that therapeutics that elevate SMN may be effective in treating SMA. We executed an image-based screen of annotated chemical libraries and discovered several classes of compounds that were able to increase cellular SMN. Among the most important was the RTK-PI3K-AKT-GSK-3 signaling cascade. Chemical inhibitors of glycogen synthase kinase 3 (GSK-3) and short hairpin RNAs (shRNAs) directed against this target elevated SMN levels primarily by stabilizing the protein. It was particularly notable that GSK-3 chemical inhibitors were also effective in motor neurons, not only in elevating SMN levels, but also in blocking the death that was produced when SMN was acutely reduced by an SMN-specific shRNA. Thus, we have established a screen capable of detecting drug-like compounds that correct the main phenotypic change underlying SMA.

There are widely discrepant views on the respiratory management of infants with spinal muscular atrophy (SMA) type I. Typically, management is palliative.

Spinal muscular atrophy (SMA), a neurodegenerative disease, is the second most common genetic disorder and the leading genetic cause of infantile death. SMA arises from the loss of Survival Motor Neuron-1 (SMN1), leading to degeneration of lower motor neurons and, consequently, the atrophy of voluntary muscles. A duplicated copy gene called SMN2 exists in humans. SMN2 is unable to fully compensate for the loss of SMN1 because it produces very low levels of functional SMN protein due to an alternative splicing event. A C/T transition in SMN2 exon 7 results in a transcript lacking exon 7 and, therefore, creates a truncated SMN protein that cannot fully compensate for the loss of SMN1. However, SMN2 is an ideal target for therapeutic strategies that redirect this critical splicing event. Previously, we developed the first trans-splicing strategy to increase the full-length mRNA and functional SMN protein from the SMN2 gene. To improve the trans-splicing efficacy, we then developed a single-vector system that expressed a trans-splicing RNA (tsRNA) and an antisense blocking the downstream splice site. This single vector greatly enhanced trans-splicing of SMN2 transcripts in vitro and in vivo. In this report, we have added a neurotrophic factor [insulin-like growth factor (IGF)-1] to this single vector to determine whether neuroprotection and SMN induction provide greater protection in an SMA animal model. Intracerebroventricular injection of the trans-splicing/IGF vector significantly increased SMN protein in brain and spinal cord of SMA?7 mice and lessened the severity of disease in a more severe mouse model as evidenced by an extension of life span and increased body mass.

Upper-extremity movement is limited in individuals with muscular weakness. This paper describes a novel, articulated upper-extremity orthosis, the Wilmington Robotic Exoskeleton (WREX), which helps people overcome this movement deficit.

The purpose of this article was to describe the use of noninvasive inspiratory and expiratory muscle aids to prevent chest wall deformities including pectus excavatum, to prevent respiratory complications of vertebral surgery, to prevent acute and long-term ventilatory insufficiency and failure in children with paralytic disorders who develop these deformities, and to permit the extubation and tracheostomy tube decanulation of "unweanable" patients. Noninvasive airway pressure aids can provide up to continuous ventilator support for patients with little or no vital capacity and can provide for effective cough flows for patients with severely dysfunctional expiratory muscles. An April 2010 consensus of clinicians from 20 centers in 14 countries reported over 1500 spinal muscular atrophy type 1 (SMA1), Duchenne muscular dystrophy (DMD), and amyotrophic lateral sclerosis (ALS) patients who survived using continuous ventilatory support without tracheostomy tubes. Four of the centers routinely extubated unweanable DMD patients so that none of their over 250 such patients has undergone tracheotomy.

Motor neuron diseases (MND) are a group of neurodegenerative disorders which are present in clinical, prognostic and genetic diversity. The most common MND are amyotrophic lateral sclerosis (ALS), proximal spinal muscular atrophy (SMA) and various forms of hereditary and sporadic lower motor neuron syndromes including hereditary motor neuropathies (HMN). Familial and "sporadic" forms of ALS and lower motor neuron syndromes are known. The essential pathogenic findings in MND have emerged from molecular biological examinations of the hereditary forms of MND. In ALS, one consistent neuropathological feature is intraneuronal protein inclusions which arise from TDP-43, FUS, SOD1 or ataxin-2 aggregations. TDP-43, FUS, SOD1 and ataxin-2 are multifunctional DNA/RNA-binding proteins which are involved in transcription regulation. SMA and HMN are associated with different genes whose gene products may also be involved in RNA processing. A disturbance in the regulation of RNA possibly represents an overlapping pathophysiological characteristic in MND. The elucidation of common pathways in the cascade of motor neuron degeneration is an essential point of departure for molecular genetically defined treatment strategies both in ALS and in hereditary and sporadic lower motor neuron syndromes.

The "International Conference on Rare Diseases" took place in Tbilisi, Georgia on September 10-11, 2010. It happened so that it became the first one dedicated to this topic in Southern Caucasus. The conference was organized by the Georgian Foundation for Genetic and Rare Diseases, JSC Traumatologist and Tbilisi State Medical University, namely, Department of Child & Adolescent Medicine. The event enjoyed a substantial backing rendered by the Charity-Humanitarian- Foundation "SOCO", and its director and founder Sandra Elisabeth Roelofs, the First Lady of Georgia, within the framework of the "SOCO" project "Alliance for Rare Diseases". The following institutions and organizations provided valuable organizational and financial support as well: National Center for Disease Control and Public Health; Health & Social Program Agency; Georgian Association of Dermatovenerologists; I. Paghava Scientific Research Institute of Pediatrics. ; The conference was co-chaired by K. Pagava, M. Chkhatarashvili, T. Chigladze. Mrs. Sandra Elisabeth Roelofs, the First Lady of Georgia inaugurated the conference by means of a video address. Minister of labor, health and social Affairs of Georgia A. Urushadze and Rector of the Tbilisi State Medical University Z. Vadachkoria greeted the participants as well. Besides the scholars, healthcare workers and Parent organizations representatives from Georgia, guests from 8 countries (Armenia, Azerbaijan, Bulgaria, Canada, Germany, Netherlands, Poland and Russian Federation) took part in this scientific event. The motto of the conference was "Bridging patients & researchers". Correspondingly the conference was devoted to the diagnostics and treatment of various specific rare diseases as well as the general approaches to various modes of their nationwide management. In all 22 communications were delivered. The participants from various countries shared their respective national as well as international experience in dealing with the issue of the rare diseases, including defining and shaping the national priorities, legislation, data gathering and multi-institutional cooperation: "Alliance for Rare Diseases" (E. Aptsiauri, I. Bulia and N. Manjaparashvili); "Patient's influence on law-making initiatives in Bulgaria" (V. Tomov, Bulgaria); "Rare Diseases - Aspects of Management" (K. Pagava, I. Korinteli, T. Kisileva, N. Uberi, Ts. Parulava, M. Kvezereli-Kopadze, I. Pagava and M. Korinteli, Georgia); "Crossing borders for Rare Diseases" (L. Siderius, Netherlands); "Information and data gathering as a compound component of the help to people with rare illnesses and their families" (S. Karimova, Russian Federation); "Armenian Experience in the field of rare diseases" (A. Matevosyan, Armenia). Presenting authors covered comprehensively various rare diseases and their management, including the following disorders: hemangioma (T. Kutubidze and B. Zenaishvili, Georgia); haemophilia and other coagulopathic diseases (R. Khomasuridze, Georgia); McCune-Albright syndrome (U. Seyidova, Azerbaijan); osteogenesis imperfecta (discussed by F. Fassier from Canada and T. Chigladze, M. Chkhatarashvili, a team of Georgian doctors); phenylketonuria (L. Margvelashvili, Georgia); Cornelia de Lange Syndrome (J. Wierzba and T. Wierzba, Poland); Sjogren's syndrome and associated complications (T. Chachibaia, Tbilisi); spinal muscular atrophy (E. Khmaladze and P. Imnadze, Georgia); ? thalassemia major (Z. Mtvarelidze, M. Kvezereli-Kopadze and A. Kvezereli-Kopadze, Georgia). Some of the participants devoted their presentations to the general issue of the rare diseases in the fields of the medicine that they are active in: dermatology (T. Kituashvili, O. Kvlividze and G. Galdava, Georgia), gastroenterology and abdominal surgery (K. Pachkoria, S. Kemoklidze, Georgia); pediatric rheumatology (M. Ioseliani, M. Lekishvili, Georgia); growth disorders, secondary to the rare diseases like Silver-Russell, Laron and Prader-Willi Syndromes (N. Davituliani, M. Rekhviashvili, R. Morgoshia and D. Metreveli, Georgia). The issues of osteoporosis in orthopaedics (Varto Seeid, Germany) and joints prostheses in cancer pathology (T. Katsitadze and T. Nozadze, Georgia) were also regarded. Various aspects of healthcare system and clinical approaches to the general issue of rare diseases and their management were discussed during the culminative Round Table session (guided by G. Abesadze from Georgia and L. Siderius from the Netherlands). It was considered to be reasonable to carry out in Tbilisi conferences on rare diseases on the regular basis. A hope was fostered that such events would contribute its mite into alleviating the burden of the rare diseases to the humankind, by disseminating the data required for improving the clinical outcome for the millions of patients suffering from the thousands of generally neglected orphan (rare) diseases.

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by mutations in the SMN1 gene. The homologous copy (SMN2) is always present in SMA patients. SMN1 gene transcripts are usually full-length (FL), but exon 7 is spliced out in a high proportion of SMN2 transcripts (delta7) (?7). Advances in drug therapy for SMA have shown that an increase in SMN mRNA and protein levels can be achieved in vitro. We performed a systematic analysis of SMN expression in primary fibroblasts and EBV-transformed lymphoblasts from seven SMA patients with varying clinical severity and different SMN1 genotypes to determine expression differences in two accessible tissues (skin and blood). The basal expression of SMN mRNA FL and ?7 in fibroblasts and lymphoblasts was analyzed by quantitative real-time PCR. The FL-SMN and FL/?7 SMN ratios were higher in control cells than in patients. Furthermore, we investigated the response of these cell lines to hydroxyurea, valproate and phenylbutyrate, drugs previously reported to upregulate SMN2. The response to treatments with these compounds was heterogeneous. We found both intra-patient and inter-patient variability even within haploidentical siblings, suggesting that tissue and individual factors may affect the response to these compounds. To optimize the stratification of patients in clinical trials, in vitro studies should be performed before enrolment so as to define each patient as a responder or non-responder to the compound under investigation.European Journal of Human Genetics advance online publication, 25 May 2011; doi:10.1038/ejhg.2011.89.

With increased use of non-invasive positive pressure ventilation (NIPPV), the prognosis of children with neuromuscular disease (NMD) has improved significantly. However, children with muscle weakness remain at risk for recurrent respiratory infection or atelectasis. We report the case of a young girl with type 1 spinal muscular atrophy (SMA type 1), dependent on NIPPV, whose conventional physiotherapy management became insufficient to clear secretions and the use of high frequency chest wall oscillation (HFCWO) as a rescue therapy. This is the only case report that has shown HFCWO to assist in secretion clearance in a child severely weak with SMA type 1. Improvements were made in self ventilation time following the initiation of HFCWO. We advocate that when faced with severe respiratory infection and compromise in patients with NMD, HFCWO may be used safely in combination with conventional physiotherapy techniques.

Changes in thigh muscle volume over 6 months were assessed using magnetic resonance imaging in 11 subjects aged 6 to 47 years with spinal muscular atrophy (4 type 2 and 7 type 3; 4 ambulatory and 3 nonambulatory). Muscle volume with normal and abnormal signal was measured using blinded, semiautomated analysis of reconstructed data. Volumes at baseline and 6 months were correlated with clinical function at each epoch. There was minimal increase in normal (0.3 ± 1.4 mL/cm) and total (0.1 ± 1.3 mL/cm) muscle. Muscle volume correlated closely with clinical function. Minimal interval change in muscle volume is consistent with the established clinical history of minimal disease progression over intervals shorter than 1 year. Relative constancy of muscle volume estimation and correlation with established functional measures suggest a role for segmental magnetic resonance imaging as a biomarker of treatment effect in future therapeutic trials.

Spinal muscle atrophy (SMA) is a progressive neuromuscular disease predominantly presenting in infancy and early childhood. Scoliosis is the most common spinal deformity in these patients and treatment in SMA patients is controversial. Treatment is usually definitive fusion. The purpose of this study is to evaluate a novel growing rod technique used to treat more involved children with SMA types I and II with scoliosis at an earlier age.

Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder that is caused by loss of the survival motor neuron gene, SMN1. SMA treatment strategies have focused on production of the SMN protein from the almost identical gene, SMN2. Valproic acid (VPA) is a histone deacetylase inhibitor that can increase SMN levels in some SMA cells or SMA patients through activation of SMN2 transcription or splicing correction of SMN2 exon 7. It remains to be clarified what concentration of VPA is required and by what mechanisms the SMN production from SMN2 is elicited. We observed that in two fibroblast cell lines from Japanese SMA patients, more than 1mM of VPA increased SMN2 expression at both the transcript and protein levels. VPA increased not only full-length (FL) transcript level but also exon 7-excluding (?7) transcript level in the cell lines and did not change the ratio of FL/?7, suggesting that SMN2 transcription was mainly activated. We also found that VPA modulated splicing factor expression: VPA increased the expression of splicing factor 2/alternative splicing factor (SF2/ASF) and decreased the expression of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). In conclusion, more than 1mM of VPA activated SMN2 transcription and modulated the expression of splicing factors in our SMA fibroblast cell lines.

Proximal spinal muscular atrophy (SMA) is caused by low levels of the SMN protein, encoded by the Survival Motor Neuron genes (SMN1 and SMN2). Mouse models of SMA can be rescued by increased SMN expression, but the timing of SMN replacement for complete rescue is unknown. Studies in zebrafish predict restoration of SMN function during embryogenesis may be important for axonal pathfinding, while the mouse models and normal human disease progression suggest that post-natal treatment may be sufficient for amelioration of disease. To evaluate the timing for SMN replacement we have generated a stably integrated Cre-inducible SMN mouse in which expression of full length SMN2 occurs after tamoxifen administration. Our temporally inducible SMN transgene is able to express SMN in embryonic, neonatal, and weanling mice and as such can be utilized in severe and mild SMA mouse models to identify the therapeutic window for SMN replacement. © 2011 Wiley-Liss, Inc.

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by loss of motor neurons in the anterior horn of the spinal cord and resultant weakness. The most common form of SMA, accounting for 95% of cases, is autosomal recessive proximal SMA associated with mutations in the survival of motor neurons (SMN1) gene. Relentless progress during the past 15 years in the understanding of the molecular genetics and pathophysiology of SMA has resulted in a unique opportunity for rational, effective therapeutic trials. The goal of SMA therapy is to increase the expression levels of the SMN protein in the correct cells at the right time. With this target in sight, investigators can now effectively screen potential therapies in vitro, test them in accurate, reliable animal models, move promising agents forward to clinical trials, and accurately diagnose patients at an early or presymptomatic stage of disease. A major challenge for the SMA community will be to prioritize and develop the most promising therapies in an efficient, timely, and safe manner with the guidance of the appropriate regulatory agencies. This review will take a historical perspective to highlight important milestones on the road to developing effective therapies for SMA.

ABSTRACT: BACKGROUND: Animal models of human diseases are essential as they allow analysis of the disease process at the cellular level and can advance therapeutics by serving as a tool for drug screening and target validation. Here we report the development of a complete genetic model of spinal muscular atrophy (SMA) in the vertebrate zebrafish to complement existing zebrafish, mouse, and invertebrate models and show its utility for testing compounds that alter SMN2 splicing. Results. The human motoneuron disease SMA is caused by low levels, as opposed to a complete absence, of the survival motor neuron protein (SMN). To generate a true model of SMA in zebrafish, we have generated a transgenic zebrafish expressing the human SMN2 gene (hSMN2), which produces only a low amount of full-length SMN, and crossed this onto the smn-/- background. We show that human SMN2 is spliced in zebrafish as it is in humans and makes low levels of SMN protein. Moreover, we show that an antisense oligonucleotide that enhances correct hSMN2 splicing increases full-length hSMN RNA in this model. When we placed this transgene on the smn mutant background it rescued the neuromuscular presynaptic SV2 defect that occurs in smn mutants and increased their survival. Conclusions. We have generated a transgenic fish carrying the human hSMN2 gene. This gene is spliced in fish as it is in humans and mice suggesting a conserved splicing mechanism in these vertebrates. Moreover, antisense targeting of an intronic splicing silencer site increased the amount of full length SMN generated from this transgene. Having this transgene on the smn mutant fish rescued the presynaptic defect and increased survival. This model of zebrafish SMA has all of the components of human SMA and can thus be used to understand motoneuron dysfunction in SMA, can be used as an vivo test for drugs or antisense approaches that increase full-length SMN, and can be developed for drug screening.

ABSTRACT: BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disorder that affects the motoneurons of the spinal anterior horn, resulting in hypotonia and muscle weakness. The disease is caused by deletion or mutation in the telomeric copy of SMN gene (SMN1) and clinical severity is in part determined by the copy number of the centromeric copy of the SMN gene (SMN2). The SMN2 mRNA lacks exon 7, resulting in a production of lower amounts of the full-length SMN protein. Knowledge of the molecular mechanism of diseases has led to the discovery of drugs capable of increasing SMN protein level through activation of SMN2 gene. One of these drugs is the valproic acid (VPA), a histone deacetylase inhibitor. METHODS: Twenty-two patients with type II and III SMA, aged between 2 and 18 years, were treated with VPA and were evaluated five times during a one-year period using the Manual Muscle Test (Medical Research Council scale-MRC), the Hammersmith Functional Motor Scale, and the Barthel Index. RESULTS: After 12 months of therapy, the patients did not gain muscle strength. The group of children with SMA type II presented a significant gain in HFMS scores during the treatment. This improvement was not observed in the group of type III patients. The analysis of the HFMS scores during the treatment period in the groups of patients younger and older than 6 years of age did not show any significant result. There was an improvement of the daily activities at the end of the VPA treatment period. Conclusion Treatment of SMA patients with VPA may be a potential alternative to alleviate the progression of the disease. TrialRegistrationcurrent control trials NCT01033331.

The mutations of survival motor neuron (SMN) gene result in spinal muscular atrophy (SMA), a common neurodegenerative disease. Some of the motor neurons undergoing cell death is the predominant characteristic in SMA pathology. However, the viability and sensitivity to stresses of other cell types also need to be determined. In this article, we established HeLa stable cell line with inducible SMN knockdown to study its viability and sensitivity to oxidative stress. SMN knockdown in the HeLa stable cell line was induced by doxycycline. The proliferative and survival rates of SMN knockdown cells with or without hydrogen peroxide (H(2)O(2)) treatment were determined. Our results showed that the proliferative rate of SMN knockdown cells decreased only slightly compared with that of the cells without doxycycline treatment. In contrast, after H(2)O(2) reached certain concentrations, the survival rate of SMN knockdown cells decreased significantly. Our data indicate that SMN knockdown alone is not critical to cell viability. However, when SMN knockdown cells are under stress, such as oxidative stress, their survival rate may significantly decrease. Our results will be helpful to prevent the detrimental effect caused by the cell death of non-motor neurons under stress in SMA patients. In addition, the cell model we established can be used to study the mechanism and screen drugs to prevent the detrimental effects in cases of SMA disease.

Preimplantation genetic diagnosis, PGD, is an established procedure allowing genetic research of the oocyte or embryo before implantation to the uterus. A neurodegenerative disorder known as spinal muscular atrophy (SMA) is the second most common lethal autosomal recessive disease in Caucasians, after cystic fibrosis. There are three clinically different types of the disease, with type I (Werding-Hoffman Disease) being the most severe. Around 98% of clinical cases of SMA are caused by the homozygous absence of a region of exons 7 and 8 of the telomeric copy of the SMN gene (SMN1) on chromosome 5 (5q13.3).

The SMN2 transgenic mouse, Tg(SMN2)89Ahmb, has emerged as the most widely used in spinal muscular atrophy (SMA) research. Here we clone the genomic integration site of the transgene and demonstrate it to be in intron 4 of the metabotropic glutamate receptor 7 (mGluR7) gene. We found that the integration of this transgene significantly reduced both mGluR7 mRNA and protein levels (24% and 9%, respectively). To determine if phenotypes associated with mGluR7 knockout mice were present in Tg(SMN2)89Ahmb containing mice, we subjected mice homozygous for the transgene to open field and seizure susceptibility tests. When compared to wild type FVB/N mice, Tg(SMN2)89Ahmb(tg/tg) mice exhibited significantly longer times in finding a safe wall-adjacent square (+54s if Smn(+/+), +90s if Smn(+/-)) as well as a significantly higher frequency of generalized seizure in response to a subthreshold dose of pentylenetrazol (0.11 vs 0.45). These findings aid in explaining the sudden unexpected death that occurs within SMA mouse colonies that contain a homozygous Tg(SMN2)89Ahmb transgene. This should be taken into account in pre-clinical studies that utilize this transgene, especially in therapy-treated SMA mice that have extended survival.

Spinal muscular atrophy (SMA) is the most common childhood neurodegenerative disease. We report an infant with SMA type 1 and discuss the recent developments in SMA genetics, pathophysiology, and possible treatment options. Because SMA type 1 remains a fatal illness for which there is not yet a cure, the focus of patient care continues to be symptomatic. Thus, the most appropriate aspects of care at present and future are also discussed.

Amyotrophic lateral sclerosis and spinal muscular atrophy are devastating neurodegenerative diseases that lead to the specific loss of motor neurons. Recently, stem cell technologies have been developed for the investigation and treatment of both diseases. Here we discuss the different stem cells currently being studied for mechanistic discovery and therapeutic development, including embryonic, adult and induced pluripotent stem cells. We also present supporting evidence for the utilization of stem cell technology in the treatment of amyotrophic lateral sclerosis and spinal muscular atrophy, and describe key issues that must be considered for the transition of stem cell therapies for motor neuron diseases from bench to bedside. Finally, we discuss the first-in-human Phase I trial currently underway examining the safety and feasibility of intraspinal stem cell injections in amyotrophic lateral sclerosis patients as a foundation for translating stem cell therapies for various neurological diseases.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by mutations in the SMN1 gene that result in a deficiency of SMN protein. One approach to treat SMA is to use antisense oligonucleotides (ASOs) to redirect the splicing of a paralogous gene, SMN2, to boost production of functional SMN. Injection of a 2'-O-2-methoxyethyl-modified ASO (ASO-10-27) into the cerebral lateral ventricles of mice with a severe form of SMA resulted in splice-mediated increases in SMN protein and in the number of motor neurons in the spinal cord, which led to improvements in muscle physiology, motor function and survival. Intrathecal infusion of ASO-10-27 into cynomolgus monkeys delivered putative therapeutic levels of the oligonucleotide to all regions of the spinal cord. These data demonstrate that central nervous system-directed ASO therapy is efficacious and that intrathecal infusion may represent a practical route for delivering this therapeutic in the clinic.

Spinal muscular atrophy is an autosomal recessive neurodegenerative disease and the most common genetic cause of infant mortality. The disease results in motor neuron loss and skeletal muscle atrophy. Spinal muscular atrophy is caused by mutations in the telomeric copy of the survival motor neuron 1 (SMN1) gene, but all patients retain a centromeric copy of the gene, SMN2. In the majority of cases, the disease severity correlates inversely with an increased SMN2 gene copy number. Because spinal muscular atrophy is both a severe and common disorder, a direct carrier testing has been beneficial to many families. The survival motor neuron protein is ubiquitously expressed and performs a role in the assembly of the spliceosome. It is still not understood why mutations in the SMN1 gene only seem to affect motor neurons. Progress has been made by developing therapeutic strategies based on understanding the pathogenesis of the disease. This review attempts to highlight some of the recent advances in the understanding of the disease with a focus on molecular diagnostics.

Spinal Muscular Atrophy (SMA) is a neurodegenerative disease with high impact in the human population, being the leading genetic cause of death in infancy. No cure is currently available for SMA, raising interest in the development of novel therapeutic strategies for this disease. Much of the effort in this sense has been aimed at increasing the SMN2-derived transcript levels, either by improving transcription rate or by reprogramming exon 7 splicing. Herein, we discuss recent findings on the regulation of SMN2 gene expression, focusing on splicing modulation as a therapeutic target. We review the literature regarding splicing factors involved in the regulation of exon 7 splicing in SMN2, and discuss the role played in this process by the RNA binding protein Sam68, a novel crucial regulator of SMN2 splicing.

Proximal spinal muscular atrophy (SMA) is a debilitating neurological disease marked by isolated lower motor neuron death and subsequent atrophy of skeletal muscle. Historically, SMA pathology was thought to be limited to lower motor neurons and the skeletal muscles they control, yet there are several reports describing the coincidence of cardiovascular abnormalities in SMA patients. As new therapies for SMA emerge, it is necessary to determine whether these non-neuromuscular systems need to be targeted. Therefore, we have characterized left ventricular (LV) function of SMA mice (SMN2+/+; SMN?7+/+; Smn-/-) and compared it with that of their unaffected littermates at 7 and 14 days of age. Anatomical and physiological measurements made by electrocardiogram and echocardiography show that affected mouse pups have a dramatic decrease in cardiac function. At 14 days of age, SMA mice have bradycardia and develop a marked dilated cardiomyopathy with a concomitant decrease in contractility. Signs of decreased cardiac function are also apparent as early as 7 days of age in SMA animals. Delivery of a survival motor neuron-1 transgene using a self-complementary adeno-associated virus serotype 9 abolished the symptom of bradycardia and significantly decreased the severity of the heart defect. We conclude that severe SMA animals have compromised cardiac function resulting at least partially from early bradycardia, which is likely attributable to aberrant autonomic signaling. Further cardiographic studies of human SMA patients are needed to clarify the clinical relevance of these findings from this SMA mouse.

Spinal Muscular Atrophy (SMA) is an autosomal recessive neurodegenerative disease that is a result of a deletion or mutation of the SMN1 (Survival Motor Neuron) gene. A duplicated and nearly identical copy, SMN2, serves as a disease modifier as increasing SMN2 copy number decreases the severity of the disease. Currently many therapeutic approaches for SMA are being developed. Therapeutic strategies aim to modulate splicing of SMN2-derived transcripts, increase SMN2 gene expression, increase neuro-protection of motor neurons, stabilize the SMN protein, replace the SMN1 gene and reconstitute the motor neuron population. It is our goal to develop a pig animal model of SMA for the development and testing of therapeutics and evaluation of toxicology. In the development of a SMA pig model, it was important to demonstrate that the human SMN2 gene would splice appropriately as the model would be based on the presence of the human SMN2 transgene. In this manuscript, we show splicing of the human SMN1 and SMN2 mini-genes in porcine cells is consistent with splicing in human cells, and we report the first genetic knockout of a gene responsible for a neurodegenerative disease in a large animal model using gene targeting with single-stranded DNA and somatic cell nuclear transfer.

Spinal muscular atrophy (SMA) is a motoneuron disorder characterized by deletions or specific mutations in the Survival Motor Neuron gene (SMN). SMN is ubiquitously expressed and has a general role in the assembly of small nuclear ribonucleoprotein (snRNP) and pre-mRNA splicing requirements. However, in motoneuron axons SMN deficiency results in inappropriate levels of certain transcripts in the distal axon, suggesting that the specific susceptibility of motoneurons to SMN deficiency is related to a specialized function in these cells. Although mouse models of SMA have been generated and are useful for in vivo and in vitro studies, the limited number of isolated MNs that could be obtained from them makes it difficult to perform biochemical, genetic and pharmacological approaches. We describe here an in vitro model of isolated embryonic mouse motoneurons in which the cellular levels of endogenous Smn are reduced. These cells show neurite degeneration and cell death after several days of Smn knockdown. We found that the over-expression of the anti-apoptotic protein Bcl-x(L) into motoneurons rescues these cells from the phenotypic changes observed. This result demonstrates that Bcl-x(L) signalling could be a possible pharmacological target of SMA therapeutics.

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by a deficiency of functional SMN protein because of mutations in SMN1. A decrease in SMN activity results in motor neuron cell loss in the spinal cord, leading to a weakness of the proximal muscles responsible for crawling, walking, head/neck control and swallowing as well as the involuntary muscles that control breathing and coughing. Thus, patients present with pulmonary manifestations, paralysis and a shortened lifespan. Gene therapy is emerging as a promising therapeutic strategy for SMA given that the molecular basis for this monogenic disorder is well established. Recent advances and findings from preclinical studies in animal models provide optimism that gene therapy might be an effective therapeutic strategy for treating SMA.

Spinal muscular atrophy (SMA) is an inherited motor neuron disease caused by the mutation of the survival motor neuron 1 (SMN1) gene and deficiency of the SMN protein. Severe SMA mice have abnormal motor function and small, immature myofibers early in development suggesting that SMN protein deficiency results in retarded muscle growth. Insulin-like growth factor 1 (IGF-1) stimulates myoblast proliferation, induces myogenic differentiation, and generates myocyte hypertrophy in vitro and in vivo. We hypothesized that increased expression of IGF-1 specifically in skeletal muscle would attenuate disease features of SMA?7 mice. SMA?7 mice overexpressing a local isoform of IGF-1 (mIGF-1) in muscle showed enlarged myofibers and a 40% increase in median survival compared to mIGF-1 negative SMA littermates (median survival = 14 vs. 10 days respectively, log rank p=0.025). Surprisingly, this was not associated with a significant improvement in motor behavior. Treatment of both mIGF-1(NEG) and mIGF-1(POS) SMA mice with the histone deacetylase inhibitor, trichostatin A (TSA), resulted in a further extension of survival and improved motor behavior, but the combination of mIGF-1 and TSA treatment was not synergistic. These results show that increased mIGF-1 expression restricted to muscle can modulate the phenotype of SMA mice indicating that therapeutics targeted to muscle alone should not be discounted as potential disease-modifying therapies in SMA. IGF-1 may warrant further investigation in mild SMA animal models and perhaps SMA patients.

Spinal and bulbar muscular atrophy is a hereditary motor neuron disease caused by trinucleotide repeat expansion in the androgen receptor gene. The disease mechanism probably involves a toxic gain of function in the mutant protein, because other mutations that cause a loss of androgen receptor function result in a different phenotype and the mutant protein is toxic in mouse models. In these models, the toxicity is ligand-dependent and is associated with protein aggregation, as well as altered transcriptional regulation, axonal transport and mitochondrial function. Various therapeutic approaches have shown efficacy in mouse models, including androgen reduction, heat shock protein 90 (HSP90) inhibition and insulin-like growth factor (IGF)-1 overexpression. Clinical trials of androgen-reducing agents have had mixed results, with indications of efficacy but no proof of clinically meaningful benefit to date. These clinical studies have established outcome measures for future trials of other agents that have been beneficial in animal studies.

OBJECTIVE: To characterize the short-term course of spinal muscular atrophy (SMA) in a genetically and clinically well-defined cohort of patients with SMA. DESIGN: A comprehensive multicenter, longitudinal, observational study. SETTING: The Pediatric Neuromuscular Clinical Research Network for SMA, a consortium of clinical investigators at 3 clinical sites. PARTICIPANTS: Sixty-five participants with SMA types 2 and 3, aged 20 months to 45 years, were prospectively evaluated. Intervention  We collected demographic and medical history information and determined the SMN 2 copy number. MAIN OUTCOME MEASURES: Clinical outcomes included measures of motor function (Gross Motor Function Measure and expanded Hammersmith Functional Motor Scale), pulmonary function (forced vital capacity), and muscle strength (myometry). Participants were evaluated every 2 months for the initial 6 months and every 3 months for the subsequent 6 months. We evaluated change over 12 months for all clinical outcomes and examined potential correlates of change over time including age, sex, SMA type, ambulatory status, SMN2 copy number, medication use, and baseline function. RESULTS: There were no significant changes over 12 months in motor function, pulmonary function, and muscle strength measures. There was evidence of motor function gain in ambulatory patients, especially in those children younger than 5 years. Scoliosis surgery during the observation period led to a subsequent decline in motor function. CONCLUSIONS: Our results confirm previous clinical reports suggesting that SMA types 2 and 3 represent chronic phenotypes that have relatively stable clinical courses. We did not detect any measurable clinical disease progression in SMA types 2 and 3 over 12 months, suggesting that clinical trials will have to be designed to measure improvement rather than stabilization of disease progression.

Spinal muscular atrophy (SMA) is a devastating genetic motoneuron disease leading to infant death. No effective therapy is currently available. It has been suggested that ?-lactam antibiotics such as ceftriaxone may offer neuroprotection in motoneuron diseases. Here, we investigate the therapeutic effect of ceftriaxone in a murine model of SMA. Treated animals present a modest, but significant ameliorated neuromuscular phenotype and increased survival, which correlate with protection of neuromuscular units. Whole gene expression profiling in treated mice demonstrates modifications in several genes including that involved in RNA metabolism toward wild-type. The neuroprotective effect seems to be mediated by multiple mechanisms that encompass the increase of the glutamate transporter Glt1, the transcription factor Nrf2, as well as SMN protein. This study provides the first evidence of a potential positive effect of this class of molecules in SMA. Further investigation of analogues with increased and more specific therapeutic effects is warrant in the development of useful therapies for SMA.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT •?Spinal muscular atrophy (SMA) is a neuromuscular disorder of childhood. •?Riluzole is an anti-excitatory agent recommended for the treatment of amyotrophic lateral sclerosis (ALS). •?Riluzole pharmacokinetics are well documented in patients with ALS. WHAT THIS STUDY ADDS •?Riluzole pharmacokinetics have never documented in patients with SMA. •?This study showed that the administration of 50?mg riluzole once a day to patients with SMA leads to total riluzole daily exposure comparable with that obtained after the administration of 50?mg twice a day in healthy volunteers or ALS patients. AIMS The objective of the present study was to assess the pharmacokinetics of riluzole in patients with spinal muscular atrophy (SMA). METHODS Fourteen patients were enrolled in an open-label, nonrandomized and repeat-dose pharmacokinetic study. All participants were assigned to receive 50?mg riluzole orally for 5 days. Riluzole plasma concentrations were determined from samples obtained at day 5. RESULTS The pharmacokinetic analysis demonstrated that a dose of 50?mg once a day was sufficient to obtain a daily total exposure [AUC(0,24?h)?=?2257?ng?ml(-1) ?h] which was comparable with results obtained in adult healthy volunteers or ALS patients in whom a dose of 50?mg twice a day is recommended. The pharmacokinetic simulation demonstrated that the administration of 50?mg twice a day could result in higher concentrations, hence reduced safety margin. CONCLUSION The dose of 50?mg once a day was chosen for the clinical trial evaluating the efficacy of riluzole in SMA patients.

Spinal Muscular Atrophy (SMA) is a neurodegenerative disease that is caused by deletion of the SMN (Survival of Motor Neuron) gene. The SMN protein is essential for cell survival and co-localized with TIA-1/R and G3BP, two characteristic markers of stress granules (SGs). To further study the SMN function in stress granules and in response to stress, we generated stable cell lines with SMN knockdown. Our data indicate that suppression of SMN drastically reduces cellular ability to form stress granules in response to stress treatment. In addition, we show that SMN deficiency sensitizes cells to sodium arsenite and H(2)O(2), two well-known stress inducers, leading to cell death at a much lower concentration of inducers in SMN knockdown cells than in control cells. Interestingly, the cell death is correlated with formation of stress granules, suggesting that involvement of SMN in formation of stress granules may play an important role in cell survival. Furthermore, rescue of SGs formation by overexpression of G3BP can reverse the defective formation of stress granules and results in partial abrogation of cell death against SMN deficiency. We deduce that modulation of stress response may be useful for potential SMN treatment.

Alternative pre-mRNA splicing is a central element of eukaryotic gene expression. Its deregulation can lead to disease and methods to change splice site selection are developed as potential therapies. Spinal muscular atrophy (SMA) is caused by the loss of the survival of motoneuron 1 gene (SMN1). A therapeutic avenue for SMA treatment is to promote exon 7 inclusion of the almost identical survival of motoneuron-2 (SMN2) gene. The splicing factor tra2-beta1 promotes inclusion of this exon and is antagonized by Protein Phosphatase 1 (PP1). To identify new compounds that promote exon 7 inclusion, we synthesized analogs of cantharidin, an inhibitor of PP1 and protein phosphatase 2A. Three classes of compounds emerged from these studies: the first class blocks PP1 and PP2A activity, blocks constitutive splicing in vitro and promotes exon 7 inclusion in vivo. The second class has no measurable effect on PP1 activity but activates PP2A. This class represents the first compounds described with these properties. These compounds cause a dephosphorylation of T33 of tra2-beta1, which promotes exon 7 inclusion. The third class had no detectable effect on phosphatase activity and could promote exon 7 via allosteric effects. Our data show that subtle changes in similar compounds can turn a phosphatase inhibitor into an activator. These chemically related compounds influence alternative splicing by distinct mechanisms.

Lower motor neuron (LMN) degeneration occurs in several diseases that affect patients from neonates to elderly and can either be genetically transmitted or occur sporadically. Among diseases involving LMN degeneration, spinal muscular atrophy (SMA) and spinal bulbar muscular atrophy (Kennedy's disease, SBMA) are pure genetic diseases linked to loss of the SMN gene (SMA) or expansion of a polyglutamine tract in the androgen receptor gene (SBMA) while amyotrophic lateral sclerosis (ALS) can either be of genetic origin or occur sporadically. In this review, our aim is to put forward the hypothesis that muscle fiber atrophy and weakness might not be a simple collateral damage of LMN degeneration, but instead that muscle fibers may be the site of crucial pathogenic events in these diseases. In SMA, the SMN gene was shown to be required for muscle structure and strength as well as for neuromuscular junction formation, and a subset of SMA patients develop myopathic pathology. In SBMA, the occurrence of myopathic histopathology in patients and animal models, along with neuromuscular phenotype of animal models expressing the androgen receptor in muscle only has lead to the proposal that SBMA may indeed be a muscle disease. Lastly, in ALS, at least part of the phenotype might be explained by pathogenic events occuring in skeletal muscle. Apart from its potential pathogenic role, skeletal muscle pathophysiological events might be a target for treatments and/or be a preferential route for targeting motor neurons.

The authors report on 2 young patients who developed drug-resistant idiopathic dystonic camptocormia (bent spine) and were treated successfully by deep brain stimulation (DBS) of the globus pallidus internus (GPi). The first patient, a 26-year-old woman, suffered for 3 years from such severe camptocormia that she became unable to walk and was confined to bed or a wheelchair. The second patient, a 21-year-old man, suffered for 6 months from less severe camptocormia; he was able to walk but only for short distances with a very bent spine, the arms in a parallel position to the legs, and the hands almost approaching the floor to potentially support him in case of a forward fall. Within a few days following DBS, both patients experienced marked clinical improvement. At most recent follow-up (44 months in one case and 42 in the other), the patients' ability to walk upright remained normal. Similar findings have only been reported recently in a few cases of camptocormia secondary to Parkinson disease or tardive dyskinesia. On the basis of the experience of these 2 idiopathic cases and the previously reported cases of secondary camptocormia with a favorable response to GPi DBS, the authors postulate that specific patterns of oscillatory activity in the GPi are vital for the maintenance of erect posture and the adoption of bipedal walking by humans.

This review aimed to characterize the gait disturbances in Parkinson disease (PD) and highlight how a rehabilitation program would affect the care of patients with PD. The typical PD gait is a type of hypokinetic gait characterized by reduced stride length and velocity; shortening of the swing phase; and increase in the stance phase, double-limb support duration, and cadence rate. In the advanced phase of PD, start hesitation, shuffling and festinating gait, propulsion, and freezing of gait (FOG) become remarkable. Notably, in PD, attention may influence gait control, and sensory cueing may improve the stride length. Our study on gait impairment in PD by using a three-dimensional motion analysis system revealed that the stride length and walking speed decreased, but there was no change in cadence. The decreased stride length was due to reduction in the range of movement at the leg and pelvic joints. A 4-week physical rehabilitation program for PD improved the stride length and walking speed;this was achieved by increasing the range of movement of at the leg and pelvic joints. We also assessed the effects of a rehabilitation program for patients with PD who experienced FOG. Although the lower limb function was more impaired in patients with PD and FOG than in those with PD without FOG, the rehabilitation program was effective even for patients with PD and FOG. FOG might be associated with functional impairment of the lower limb as well as dysfunction of the fronto-basal ganglia circuit. We also reported 3 cases of camptocormia (bent spine syndrome) with autonomic dysfunction and rapid eye movement (REM) sleep behavior disorders (RBD) and compared their symptoms with those reported elsewhere. We think that the pedunculopontine nuclear area may control the postural muscle tone and locomotion in PD. On the basis of the results of our rehabilitation programs, we speculate that physical modalities may modify synaptic plasticity by utilizing the cerebellar and/or afferent sensory system. These alternative systems are believed to be functionally intact in patients with PD.

The purpose of this study was to evaluate the safety and efficacy of hydroxyurea (HU) in spinal muscular atrophy (SMA) in a randomized, double-blind, placebo-controlled trial.

Small molecules that increase full-length survivor motor neuron (SMN) gene transcript are promising therapeutic candidates for spinal muscular atrophy (SMA). Hydroxyurea (HU) has recently been shown to increase full-length SMN transcript in cultured lymphocytes from patients with SMA. We investigate the mechanism by which HU enhances full-length SMN2 gene expression in SMA lymphocytes. Nitric oxide (NO) is a major intracellular metabolite of HU. We test whether NO donors can themselves enhance full-length SMN2 expression. Eighteen cell lines (five type I, five type II, six type III SMA, and two non-SMA controls) were treated with or without NO donors for 48 h. SMA cells treated with HU and three NO donors: two long-acting donors, Deta-NONOate and S-nitrosoglutathione, and one short-acting donor, 3-ethyl-3-(ethylaminoethyl)-1-hydroxy-2-oxo-1-triazene, resulted in significant increase in full-length SMN2 mRNA. These effects were abolished by co-treatment with an NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide. One short-acting NO donor, S-nitroso-N-acetyl-DL-penicillamine, failed to show significant effect on full-length SMN2 expression, possibly due to high degree of cytotoxicity. These results were observed using both densitometry and quantitative PCR methods. We conclude that HU enhances SMN2 expression through the release of NO. NO donors may themselves be considered as new therapeutic candidates for SMA.

This article reviews clinical, genetic, and therapeutic advances in spinal muscular atrophies (SMAs), inherited disorders characterized by motor neuron loss and muscle weakness.

OBJECTIVE: We estimated the prevalence of children with life-threatening conditions (LTC) cared for in the military health system (MHS) in response to a Congressional inquiry and to inform program planning. METHODS: We developed a case definition of LTC, using the concept "death trajectory"(1,2) to define our cases. We conducted an unduplicated count of children with LTC in the MHS database during FY 2001/FY 2002 using selected ICD-9 codes based on our case definition. We then surveyed the literature for reported prevalence of LTC among children with similar case definitions. The concept of "death trajectory" describes non-categorical life-threatening conditions of four types: progressive decline to death (e.g., spinal muscular atrophy); intermittent periods of intensive care to maintain quality-of-life (e.g., cystic fibrosis); curative treatment is possible but may fail (e.g., childhood cancers); and severe but non-progressive disability with extreme health vulnerability (e.g., spastic quadriplegia with tracheotomy). RESULTS: There were 3,976 children identified with LTC in a population of 2.6 million children, for a prevalence of 0.15%. Conclusion: A prevalence of 0.15% for children with LTC in the MHS population agrees closely with that derived for similar case definitions by other authors among populations of children in other single-payer health care systems (i.e., United Kingdom). The method used here may apply to similar health care systems with ICD 9 codes in a searchable database.

Reliable outcome measures that reflect the underlying disease process and correlate with motor function in children with SMA are needed for clinical trials. Maximum ulnar compound muscle action potential (CMAP) data were collected at two visits over a 4-6-week period in children with SMA types II and III, 2-17 years of age, at four academic centers. Primary functional outcome measures included the Modified Hammersmith Functional Motor Scale (MHFMS) and MHFMS-Extend. CMAP negative peak amplitude and area showed excellent discrimination between the ambulatory and non-ambulatory SMA cohorts (ROC = 0.88). CMAP had excellent test-retest reliability (ICC = 0.96-0.97, n = 64) and moderate to strong correlation with the MHFMS and MHFMS-Extend (r = 0.61-0.73, n = 68, P < 0.001). Maximum ulnar CMAP amplitude and area is a feasible, valid, and reliable outcome measure for use in pediatric multicenter clinical trials in SMA. CMAP correlates well with motor function and has potential value as a relevant surrogate for disease status.

Neurologists should anticipate and recognize the onset of respiratory failure in patients with neuromuscular diseases. Symptoms vary according to the speed of onset of respiratory muscle weakness. Catastrophic situations usually occur in three clinical scenarios: 1) incorrect management of acute respiratory failure of neuromuscular origin, autonomic dysfunction or during general anaesthesia of patients with neuromuscular diseases ; 2) incorrect prognosis and treatment due to the lack of a correct diagnosis. This situation is more common in ventilated patients with associated muscular weakness, acute neuropathies or motor neuron disease, and 3) inappropriate medical intervention in patients with neuromuscular disease with a definitive diagnosis but longstanding disease (amyotrophic lateral sclerosis, spinal muscular atrophy, myotonic dystrophy and other muscular dystrophies).

The cellular and molecular environment present in the fetus and early newborn provides an excellent opportunity for effective gene transfer. Innate and pre-existing anti-vector immunity may be attenuated or absent and the adaptive immune system predisposed to tolerance towards xenoproteins. Stem cell and progenitor cell populations are abundant, active and accessible. In addition, for treatment of early lethal genetic diseases of the nervous system, the overarching advantage may be that early gene supplementation prevents the onset of irreversible pathological changes. Gene transfer to the fetal mouse nervous system was achieved, albeit inefficiently, as far back as the mid-1980s. Recently, improvements in vector design and production have culminated in near-complete correction of a mouse model of spinal muscular atrophy. In the present article, we review perinatal gene transfer from both a therapeutic and technological perspective.

Spinal muscular atrophy (SMA) is the most common genetic disease leading to infant mortality. This neuromuscular disorder is caused by loss or mutation of the telomeric copy of the "survival of motor neuron" (Smn) gene, termed SMN1. Loss of SMN1 leads to reduced SMN protein levels, inducing degeneration of motor neurons (MN) and progressive muscle weakness and atrophy. To date, SMA remains incurable due to the lack of a method to deliver therapeutically active molecules to the spinal cord. Gene therapy, consisting of reintroducing SMN1 in MNs, is an attractive approach for SMA. Here we used postnatal day 1 systemic injection of scAAV9 vectors carrying a codon-optimized SMN1 sequence and a chimeric intron placed downstream of the strong PGK promoter (SMNopti) to overexpress the human SMN protein in a mouse model of severe SMA. Survival analysis showed that this treatment rescued 100% of the mice, increasing life expectancy from 27 to over 340 days in mice that normally survive about 13 days (median survival of 200 days). The systemic scAAV9 therapy mediated complete correction of motor function, prevented motor neuron death, and rescued the weight loss phenotype close to normal. This study reports the most efficient rescue of SMA mice to date after a single intravenous injection of an optimized SMN-encoding scAAV9, highlighting the considerable potential of this method for treatment of human SMA.

Spinal muscular atrophy (SMA) is a major genetic cause of death in childhood characterized by marked muscle weakness. To investigate mechanisms underlying motor impairment in SMA, we examined the spinal and neuromuscular circuitry governing hindlimb ambulatory behavior in SMA model mice (SMN?7). In the neuromuscular circuitry, we found that nearly all neuromuscular junctions (NMJs) in hindlimb muscles of SMN?7 mice remained fully innervated at the disease end stage and were capable of eliciting muscle contraction, despite a modest reduction in quantal content. In the spinal circuitry, we observed a ?28% loss of synapses onto spinal motoneurons in the lateral column of lumbar segments 3-5, and a significant reduction in proprioceptive sensory neurons, which may contribute to the 50% reduction in vesicular glutamate transporter 1(VGLUT1)-positive synapses onto SMN?7 motoneurons. In addition, there was an increase in the association of activated microglia with SMN?7 motoneurons. Together, our results present a novel concept that synaptic defects occur at multiple levels of the spinal and neuromuscular circuitry in SMN?7 mice, and that proprioceptive spinal synapses could be a potential target for SMA therapy.

We successfully performed transection of the innominate artery in a patient with a neuromuscular disorder through minimally invasive access after confirming the anatomical relationships of the vessel using 3-dimensional multidetector-row computed tomographic angiography. A 16-year-old girl with spinal muscular atrophy type 1 had been on long-term mechanical ventilation with a tracheostomy. She had scoliosis and tracheomalacia. Bronchoscopy showed a flattened and narrow lower trachea and an anterior pulsatile compression by the innominate artery. She underwent transection of the innominate artery to prevent tracheoinnominate artery fistula formation. Based on preoperative 3-dimensional multidetector-row computed tomographic angiography images, the innominate artery was transected through a small transverse curvilinear skin incision just below the suprasternal notch and an oblique partial manubriotomy from the suprasternal notch to the first left intercostal space.

Spinal muscular atrophy (SMA) is the second most common autosomal recessive disease and is a leading cause of infantile death. This disease has a carrier frequency of 1:35, affecting 1/6,000 live births and is the result of a homozygous loss of the survival of motor neuron 1 gene (SMN1). Humans carry a nearly identical copy gene, SMN2, that codes for very low levels of the full-length protein, ?10% when compared to SMN1. This is due to one silent nucleotide transition at the 5' end of exon 7 that disrupts a critical splicing regulatory domain. The underlying protein coding region, however, is unaffected by this and other nucleotide differences between SMN1 and SMN2. SMN2 has, therefore, been envisioned as an outstanding target for therapeutic strategies that 1) increases SMN2 expression, 2) alters the pre-messenger RNA splicing of exon 7 or 3) stabilizes the SMN2-derived protein products. In this review, we summarize numerous therapeutic approaches including nucleic acid-based and drug-oriented therapies that have progressed toward treating SMA.

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate clinical and functional success by all pedicle screw construct in paralytic neuromuscular scoliosis (NMS) with poor pulmonary functions (PFT). SUMMARY OF BACKGROUND: Duchene muscular dystrophy and spinal muscular atrophy are often associated with poor PFT and the development of scoliosis simultaneously. Poor PFT often make surgeons reluctant to operate. METHODS: Eighteen paralytic NMS patients who had preoperative forced vital capacity (FVC) <30% were operated with all pedicle screw construct. Average preoperative, postoperative, and final follow-up Cobb angle, pelvic obliquity, thoracic kyphosis and lumbar lordosis, PFT (FVC% and forced expiratory volume 1%), and preoperative and follow-up functional status were analyzed. Perioperative and postoperative complications were also noted. RESULTS: The average follow-up was 31.6±7.7 months. There was significant improvement in Cobb angle (61.7%) and pelvic obliquity (56.7%), postoperatively (P<0.001). All corrections were maintained at final follow-up. FVC was decreased from 25.2±4.7% preoperatively to 24.2±5.0%, 6 weeks postoperatively (P=0.067); and on follow-up it further decreased to 20.6±3.9% (P<0.0001) (1.8%/y). Forced Expiratory Volume 1 also decreased from 22.7±4.5% preoperatively to 21.8±4.2% postoperatively (P=0.037) and was 19.8±3.8% at final follow-up (P<0.0001) (1.1%/y). However, none of the patients had any respiratory complications postoperatively. Functional status was improved in 6 patients and they were able to sit without support (P=0.027). Eight (44.4%) perioperative complications (5 pulmonary, 1 intraoperative death, and 2 others) were noticed. Postoperatively, 4 patients (23.5%) had complications; coccygodynia, back sore because of screw prominence, impingement of iliac screw, and loosening of the rod from L5 screw. All the patients were satisfied with the treatment. There were no major pulmonary complications requiring admission postoperatively. CONCLUSIONS: Although complications are associated with the treatment of paralytic NMS, a good clinical and function outcome suggests that poor PFT should not be considered as a contraindication of scoliosis surgery.

Spinal muscular atrophy (SMA), an autosomal recessive genetic disorder, is characterized by the selective degeneration of lower motor neurons, leading to muscle atrophy and, in the most severe cases, paralysis and death. Deletions and point mutations cause reduced levels of the widely expressed survival motor neuron (SMN) protein, which has been implicated in a range of cellular processes. The mechanisms underlying disease pathogenesis are unclear and there is no effective treatment. Several animal models have been developed to study SMN function including the nematode, Caenorhabditis elegans, where a large deletion in the gene homologous to SMN, smn-1, results in neuromuscular dysfunction and larval lethality. Although useful, this null mutant, smn-1(ok355), is not well-suited to drug screening. We report the isolation and characterization of smn-1(cb131), a novel allele encoding a substitution in a highly conserved residue of exon 2, resembling a point mutation found in a patient with type IIIb SMA. smn-1(cb131) animals display milder yet similar defects compared to the smn-1 null mutant. Using an automated phenotyping system, mutants were shown to swim slower than wild type animals. This phenotype was used to screen a library of 1,040 chemical compounds for drugs that ameliorate the defect, highlighting six for subsequent testing. 4-aminopyridine, gaboxadol hydrochloride and N-acetylneuraminic acid all showed ability to significantly rescue at least one aspect of smn-1 phenotypic dysfunction. These findings may assist in accelerating the development of drugs for the treatment of SMA.

ABSTRACT: BACKGROUND: Progranulin (PGRN) encoded by the GRN gene, is a secreted glycoprotein growth factor that has been implicated in many physiological and pathophysiological processes. PGRN haploinsufficiency caused by autosomal dominant mutations within the GRN gene leads to progressive neuronal atrophy in the form of frontotemporal lobar degeneration (FTLD). This form of the disease is associated with neuronal inclusions that bear the ubiquitinated TAR DNA Binding Protein-43 (TDP-43) molecular signature (FTLD-U). The neurotrophic properties of PGRN in vitro have recently been reported but the role of PGRN in neurons is not well understood. Here we document the neuronal expression and functions of PGRN in spinal cord motoneuron (MN) maturation and branching in vivo using zebrafish, a well established model of vertebrate embryonic development. RESULTS: Whole-mount in situ hybridization and immunohistochemical analyses of zebrafish embryos revealed that zfPGRN-A is expressed within the peripheral and central nervous systems including the caudal primary (CaP) MNs within the spinal cord. Knockdown of zfPGRN-A mRNA translation mediated by antisense morpholino oligonucleotides disrupted normal CaP MN development resulting in both truncated MNs and inappropriate early branching. Ectopic over-expression of zfPGRN-A mRNA resulted in increased MN branching and rescued the truncation defects brought about by knockdown of zfPGRN-A expression. The ability of PGRN to interact with established MN developmental pathways was tested. PGRN over-expression was found to reverse the truncation defect resulting from knockdown of Survival of motor neuron 1 (smn1). This is involved in small ribonucleoprotein biogenesis RNA processing, mutations of which cause Spinal Muscular Atrophy (SMA) in humans. PGRN did not reverse the MN defects caused by interfering with the neuronal guidance pathway by knockdown of expression of NRP-1, a semaphorin co-receptor. CONCLUSIONS: Expression of PGRN within MNs and the observed phenotypes resulting from mRNA knockdown and over-expression are consistent with a role in the regulation of spinal cord MN development and branching. This study presents the first in vivo demonstration of the neurotrophic properties of PGRN and suggests possible future therapeutic applications in the treatment of neurodegenerative diseases.

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by degeneration and loss of lower motor neurons in the spinal cord and brainstem. Clinically, SMA has been classified into four types, according to the maximum function attained. The disease is caused by deletion or mutation of the telomeric copy of the SMN gene (SMN1), and the clinical severity is in part determined by the copy number of the centromeric SMN gene (SMN2). The SMN2 mRNA lacks exon 7, resulting in reduced production of the full-length SMN protein. Treatment of SMA consists of supportive care, although many drugs have been demonstrated to improve muscle strength and motor function of patients. The development of animal models of SMA has led to better interpretation of the physiopathology of the disease and testing of potential drug targets. Several mechanisms have been targeted in SMA drug trials, including neuroprotection, neurogenesis, energy metabolism improvement, anabolic stimulation and increment of SMN2 transcripts. Gene therapy and cell transplantation have also been tested in murine SMA.

In this review we consider recent work using zebrafish to validate and study the functional consequences of mutations of human genes implicated in a broad range of degenerative and developmental disorders of the brain and spinal cord. Also we present technical considerations for those wishing to study their own genes of interest by taking advantage of this easily manipulated and clinically relevant model organism. Zebrafish permit mutational analyses of genetic function (gain or loss of function) and the rapid validation of human variants as pathological mutations. In particular neural degeneration can be characterized at genetic, cellular, functional and behavioral levels. Zebrafish have been used to knockdown or express mutations in zebrafish homologs of human genes and to directly express human genes bearing mutations related to neurodegenerative disorders such as spinal muscular atrophy, ataxia, hereditary spastic paraplegia, amyotrophic lateral sclerosis (ALS), epilepsy, Huntington's disease, Parkinson's disease, fronto-temporal dementia and Alzheimer's disease. More recently we have been using zebrafish to validate mutations of synaptic genes discovered by large-scale genomic approaches in developmental disorders such as autism, schizophrenia and non-syndromic mental retardation. Advances in zebrafish genetics such as multigenic analyses and chemical genetics now offer a unique potential for disease research. Thus zebrafish hold much promise for advancing the functional genomics of human diseases, the understanding of the genetics and cell biology of degenerative and developmental disorders, and the discovery of therapeutics.

ABSTRACT Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by degeneration of alpha motor neurons. This case report describes an aquatic therapy program and the outcomes for a 3-year-old girl with type III SMA. Motor skills were examined using the 88-item Gross Motor Function Measure (GMFM), the Peabody Developmental Motor Scales (PDMS-2), and the GAITRite system. The child received aquatic therapy twice per week for 45-min sessions, for 14 weeks. The intervention included aquatic activities designed to improve gross motor skills and age-appropriate functional mobility. The GMFM total score improved by 11% following the intervention. The Standing Dimension score improved by 28% and the Walking, Running, and Jumping Dimension score improved by 18%. The gross motor quotient for the PDMS-2 improved from 66 to 74. The child's gait showed improvement in walking velocity, stride length, and single-limb support time as a percentage of the gait cycle. The outcomes of this case report demonstrate the successful improvement of gross motor function and gait in a 3-year-old child with SMA. This study provides clinical information for therapists utilizing aquatic therapy as a modality for children with neuromuscular disorders.

AIM: The aim of this study was to determine the role of parents after extubation of their children affected by Spinal Muscular Atrophy Type 1 (SMA1) in the Pediatric Intensive Care Unit. Currently, children affected by SMA1 are often treated with non-invasive mechanical ventilation and mechanical support of cough. During the first two or three years of life they frequently present severe respiratory failure requiring intubation. Extubation may be at severe risk of failure even because of inadequate care. METHODS: Parents of SMA1 children were offered an early education on the most critical aspects and a training in non-invasive respiratory support after diagnosis. They were asked and allowed to stay as longer as possible with their child after extubation. Quality and quantity of care given by parents during the first 24 hours after extubation were recorded. RESULTS: All parents participated to the success of the weaning procedure: they gave continuous care and all children could be extubated. CONCLUSION: The presence of parents after extubation of SMA1 patients is important for the success of the procedure; otherwise, the presence of a skilled nurse is needed, with a nurse-patient ratio of 1:1.

Background Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by mutations of the SMN1 gene. Based on severity, three forms of SMA are recognised (types I-III). All patients usually have 2-4 copies of a highly homologous gene (SMN2) which produces insufficient levels of functional survival motor neuron (SMN) protein. Recently, evidence has been provided that SMN2 expression can be enhanced in vitro by salbutamol, a β2-adrenergic agonist. This compound has also been shown to improve motor function of SMA patients in two different pilot trials. Aim To evaluate the in vivo molecular efficacy of salbutamol in SMA patients. Methods Twelve type II-III patients took salbutamol orally for 6â??months. SMN2 full length transcript levels were determined in peripheral blood leucocytes by absolute real-time PCR, at baseline and after 3 and 6â??months of treatment. Results A significant and constant increase in SMN2 full length transcript levels was detected; the response was directly proportional to SMN2 gene copy number. Conclusions The data strongly support salbutamol as a candidate for treating SMA, and suggest that SMN2 copy number may predict the molecular response to treatment and may be a useful randomisation parameter in a double blind placebo controlled clinical trial design.

BACKGROUND: Spinal and bulbar muscular atrophy is a hereditary motor neuron disease caused by the expansion of a polyglutamine tract in the androgen receptor. At present there are no treatments for spinal and bulbar muscular atrophy, although leuprorelin suppressed the accumulation of pathogenic androgen receptors in a phase 2 trial. We aimed to assess the efficacy and safety of leuprorelin for spinal and bulbar muscular atrophy. METHODS: The Japan SBMA Interventional Trial for TAP-144-SR (JASMITT) was a 48-week, randomised, double-blind, placebo-controlled trial done at 14 hospitals between August, 2006, and March, 2008. Patients with spinal and bulbar muscular atrophy were randomly assigned (1:1) by minimisation to subcutaneous 11.25 mg leuprorelin or identical placebo every 12 weeks. Patients and investigators were masked to treatment allocation. The primary endpoint was pharyngeal barium residue, which indicates incomplete bolus clearance, measured at week 48 by videofluorography. All patients who were randomly assigned and who were assessed with videofluorography at least once were included in the analyses. This study is registered with the JMACCT clinical trials registry, number JMA-IIA00009, and the UMIN clinical trials registry, number UMIN000000465. FINDINGS: 204 patients were randomly assigned and 199 started treatment: 100 with leuprorelin and 99 with placebo. At week 48, the pharyngeal barium residue after initial swallowing had changed by -5.1% (SD 21.0) in the leuprorelin group and by 0.2% (18.2) in the placebo group (difference between groups -5.3%; 95% CI -10.8 to 0.3; p=0.063). The mean difference in pharyngeal barium residue after piecemeal deglutition at week 48 was -3.2% (-6.4 to 0.0; p=0.049), but there was no significant difference between the groups after covariate adjustment for the baseline data (-4.1 to 1.6; p=0.392). In a predefined subgroup analysis, leuprorelin treatment was associated with a greater reduction in barium residue after initial swallowing than was placebo in patients with a disease duration less than 10 years (difference between groups -9.8, -17.1 to -2.5; p=0.009). There were no significant differences in the number of drug-related adverse events between groups (57 of 100 in the leuprorelin group and 54 of 99 in the placebo group; p=0.727). INTERPRETATION: 48 weeks of treatment with leuprorelin did not show significant effects on swallowing function in patients with spinal and bulbar muscular atrophy, although it was well tolerated. Disease duration might influence the efficacy of leuprorelin and thus further clinical trials with sensitive outcome measures should be done in subpopulations of patients. FUNDING: Large Scale Clinical Trial Network Project, Japan and Takeda Pharmaceuticals.

PURPOSE OF REVIEW: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by mutations in the survival motor neuron (SMN1) gene, affecting approximately 1 in 10 000 live births. Even though a specific therapy for SMA is not currently available, a newborn screening test may allow the child to be enrolled in a clinical trial before irreversible neuronal loss occurs and enable patients to obtain more proactive treatments. Until an effective treatment is found to cure or arrest the progression of the disease, prevention of new cases through carrier detection and prenatal diagnosis becomes extremely important. RECENT FINDINGS: The correlation between the SMA phenotype and the SMN2 copy number and the demonstration that sufficient SMN protein from SMN2 in transgenic mice can ameliorate the disease has made the SMN2 gene an obvious target that is being modulated in current therapeutic trials. Most recent work, utilizing gene therapy, has also shown a rescue of the phenotype in the mouse model. Since SMA children are often asymptomatic at birth, newborn screening is a means which will allow the implementation of the most early intervention to take place, before the irreversible loss of motor neurons. Since there is no effective cure for SMA presently, prevention through the identification of carriers becomes an important alternative and has recently been initiated. SUMMARY: Treatment and prevention of SMA are complementary responses to the scourge presented by SMA. This review first describes the molecular genetics of SMA and then focuses on newborn screening, as a means of ensuring the earliest intervention, and the prevention through population carrier screening.

GM2 gangliosidosis type Sandhoff is caused by a defect of beta-hexosaminidase, an enzyme involved in the catabolism of gangliosides. It has been proposed that substrate reduction therapy using N-butyl-deoxynojirimycin (miglustat) may delay neurological progression, at least in late-onset forms of GM2 gangliosidosis. We report the results of a 3-year treatment with miglustat (100 mg t.i.d) in a patient with chronic Sandhoff disease manifesting with an atypical, spinal muscular atrophy phenotype. The follow-up included serial neurological examinations, blood tests, abdominal ultrasound, and neurophysiologic, cognitive, brain, and muscle MRI studies. We document some minor effects on neurological progression in chronic Sandhoff disease by miglustat treatment, confirming the necessity of phase II therapeutic trials including early-stage patients in order to assess its putative efficacy in chronic Sandhoff disease.

BACKGROUND: Valproic acid (VPA) has demonstrated potential as a therapeutic candidate for spinal muscular atrophy (SMA) in vitro and in vivo. METHODS: Two cohorts of subjects were enrolled in the SMA CARNIVAL TRIAL, a non-ambulatory group of "sitters" (cohort 1) and an ambulatory group of "walkers" (cohort 2). Here, we present results for cohort 1: a multicenter phase II randomized double-blind intention-to-treat protocol in non-ambulatory SMA subjects 2-8 years of age. Sixty-one subjects were randomized 1ratio1 to placebo or treatment for the first six months; all received active treatment the subsequent six months. The primary outcome was change in the modified Hammersmith Functional Motor Scale (MHFMS) score following six months of treatment. Secondary outcomes included safety and adverse event data, and change in MHFMS score for twelve versus six months of active treatment, body composition, quantitative SMN mRNA levels, maximum ulnar CMAP amplitudes, myometry and PFT measures. RESULTS: At 6 months, there was no difference in change from the baseline MHFMS score between treatment and placebo groups (difference = 0.643, 95% CI = -1.22-2.51). Adverse events occurred in >80% of subjects and were more common in the treatment group. Excessive weight gain was the most frequent drug-related adverse event, and increased fat mass was negatively related to change in MHFMS values (p = 0.0409). Post-hoc analysis found that children ages two to three years that received 12 months treatment, when adjusted for baseline weight, had significantly improved MHFMS scores (p = 0.03) compared to those who received placebo the first six months. A linear regression analysis limited to the influence of age demonstrates young age as a significant factor in improved MHFMS scores (p = 0.007). CONCLUSIONS: This study demonstrated no benefit from six months treatment with VPA and L-carnitine in a young non-ambulatory cohort of subjects with SMA. Weight gain, age and treatment duration were significant confounding variables that should be considered in the design of future trials. TRIAL REGISTRY: Clinicaltrials.gov NCT00227266.

Spinal muscular atrophy (SMA), a lethal neurodegenerative disease that occurs in childhood, is caused by the misexpression of the survival of motor neuron (SMN) protein in motor neurons. It is still unclear whether activating motor units in SMA corrects the delay in the postnatal maturation of the motor unit resulting in an enhanced neuroprotection. In the present work, we demonstrate that an adequate NMDA receptor activation in a type 2 SMA mouse model significantly accelerated motor unit postnatal maturation, counteracted apoptosis in the spinal cord, and induced a marked increase of SMN expression resulting from a modification of SMN2 gene transcription pattern. These beneficial effects were dependent on the level of NMDA receptor activation since a treatment with high doses of NMDA led to an acceleration of the motor unit maturation but favored the apoptotic process and decreased SMN expression. In addition, these results suggest that the NMDA-induced acceleration of motor unit postnatal maturation occurred independently of SMN. The NMDA receptor activating treatment strongly extended the life span in two different mouse models of severe SMA. The analysis of the intracellular signaling cascade that lay downstream the activated NMDA receptor revealed an unexpected reactivation of the CaMKII/AKT/CREB (cAMP response element-binding protein) pathway that induced an enhanced SMN expression. Therefore, pharmacological activation of spinal NMDA receptors could constitute a useful strategy for both increasing SMN expression and limiting motor neuron death in SMA spinal cord.

Effective therapies are needed for amyotrophic lateral sclerosis (ALS), a debilitating and fatal motor neuron disease. Cell and animal models of ALS are beginning to reveal possible principles governing the biology of motor neuron-selective vulnerability that implicate mitochondria and the mitochondrial permeability pore (mPTP). Proteins associated with the mPTP are known to be enriched in motor neurons and the genetic deletion of a major regulator of the mPTP has robust effects in ALS transgenic mice, delaying disease onset and extending survival. Thus, the mPTP is a rational, mechanism-based target for the development of drugs designed to treat ALS. Trophos SA has discovered olesoxime (TRO-19622), a small-molecule with a cholesterol-like structure, which has remarkable neuroprotective properties for motor neurons in cell culture and in rodents. Olesoxime appears to act on mitochondria, possibly at the mPTP. Phase I clinical trials of olesoxime have been completed successfully. Olesoxime is well tolerated and achieves levels predicted to be clinically effective when administered orally. It has been granted orphan drug status for the treatment of ALS in the US and for the treatment of spinal muscular atrophy in the EU. Phase II/III clinical trials are in progress in Europe.

Antisense oligonucleotides (ASOs) can be used to alter the splicing of a gene and either restore production of a required protein or eliminate a toxic product. In this issue of Genes & Development, Hua and colleagues (pp. 1634-1644) show that ASOs directed against an intron splice silencer (ISS) in the survival motor neuron 2 (SMN2) gene alter the amount of full-length SMN transcript in the nervous system, restoring SMN to levels that could correct spinal muscular atrophy (SMA).

OBJECTIVE: To report on recent genetic and molecular discoveries and on future prospects for the treatment of spinal muscular atrophy (SMA), thereby helping healthcare professionals to make a quick diagnosis and provide appropriate and timely therapeutic support. SOURCES: Information was collected from scientific articles published in the last 2 decades, retrieved from the databases SciELO, PubMed, and MEDLINE. SUMMARY OF THE FINDINGS: SMA is a neurodegenerative disorder with autosomal recessive genetic heredity. It is caused by a homozygous deletion of the survival motor neuron (SMN1) gene. This genetic alteration results in reduced levels of the SMN protein, leading to degeneration of alpha motor neurons of the spinal cord and resulting in muscle weakness and progressive symmetrical proximal paralysis. It is known that basic nutritional and respiratory care and physiotherapy can be important to delaying disease progression and prolonging patients' lives. Several drugs are being tested, some new, others, such as valproic acid, already known; paralysis can be halted, but not reversed. CONCLUSIONS: SMA is a difficult to diagnose disorder, because it is little known, and treatment is uncertain. Pharmacological treatments and supportive therapies are not yet able to recover motor neurons or muscle cells that have already been lost, but are aimed at delaying disease progression and improving patients' residual muscle function, as well as offering better quality of life and life expectancy.

Proximal spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. Traditionally SMA has been described as a motor neuron disease, however there is a growing body of evidence that arrhythmia and/or cardiomyopathy may present in SMA patients at an increased frequency. Here, we ask whether SMA model mice possess such phenotypes. We find SMA mice suffer from severe bradyarrhythmia characterized by progressive heart block and impaired ventricular depolarization. Echocardiography further confirms functional cardiac deficits in SMA mice. Additional investigations show evidence of both sympathetic innervation defects and cardiomyopathy at late stages of disease. Based upon these data we propose a model in which decreased sympathetic innervation causes autonomic imbalance. Such imbalance would be characterized by a relative increase in the level of vagal tone controlling heart rate, which is consistent with bradyarrhythmia and progressive heart block. Finally, treatment with the histone deacetylase inhibitor Trichostatin A, a drug known to benefit phenotypes of SMA model mice, produces prolonged maturation of the SMA heartbeat and an increase in cardiac size. Treated mice maintain measures of motor function throughout extended survival though they ultimately reach death endpoints in association with a progression of bradyarrhythmia. These data represent the novel identification of cardiac arrhythmia as an early and progressive feature of murine SMA while providing several new, quantitative indices of mouse health. Together with clinical cases that report similar symptoms, this reveals a new area of investigation that will be important to address as we move SMA therapeutics towards clinical success.

Spinal muscular atrophy (SMA) is a common and often fatal neurodegenerative disease that primarily afflicts infants and young children. SMA is caused by abnormally low levels of the survival motor neuron (SMN) protein resulting from a combination of recessively inherited mutations in the SMN1 gene and the presence of an almost identical but partially functional copy gene, SMN2. Absence of the uniquely human SMN2 gene in SMA patients has never been reported because the SMN protein is indispensable for cell survival. Modeling SMA in animals therefore poses a challenge. This review describes the different strategies used to overcome this hurdle and model SMA in mice. We highlight new and emerging insights regarding SMA gained by studying the mice and illustrate how the animals serve as important tools to understand and eventually treat the human disease.

Motor neurons are large, highly polarised cells with very long axons and a requirement for precise spatial and temporal gene expression. Neurodegenerative disorders characterised by selective motor neuron vulnerability include various forms of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). A rapid expansion in knowledge on the pathophysiology of motor neuron degeneration has occurred in recent years, largely through the identification of genes leading to familial forms of ALS and SMA. The major emerging theme is that motor neuron degeneration can result from mutation in genes that encode factors important for ribonucleoprotein biogenesis and RNA processing, including splicing regulation, transcript stabilisation, translational repression and localisation of mRNA. Complete understanding of how these pathways interact and elucidation of specialised mechanisms for mRNA targeting and processing in motor neurons are likely to produce new targets for therapy in ALS and related disorders.

Proximal spinal muscular atrophy (SMA) is a debilitating neurological disease marked by isolated lower motor neuron death and subsequent atrophy of skeletal muscle. Historically, SMA pathology was thought to be limited to lower motor neurons and the skeletal muscles they control, yet there are several reports describing the coincidence of cardiovascular abnormalities in SMA patients. As new therapies for SMA emerge, it is necessary to determine whether these non-neuromuscular systems need to be targeted. Therefore, we have characterized left ventricular (LV) function of SMA mice (SMN2+/+; SMNDelta7+/+; Smn-/-) and compared it to that of their unaffected littermates at 7 and 14 days of age. Anatomical and physiological measurements made by electrocardiogram (ECG) and echocardiography show that affected mouse pups have a dramatic decrease in cardiac function. At 14 days of age, SMA mice have bradycardia and develop a marked dilated cardiomyopathy with a concomitant decrease in contractility. Signs of decreased cardiac function are also apparent as early as 7 days of age in SMA animals. Delivery of an SMN1 transgene using a self-complementary adeno-associated virus serotype 9 abolished the symptom of bradycardia and significantly decreased the severity of the heart defect. We conclude that severe SMA animals have compromised cardiac function resulting at least partially from early bradycardia, which is likely attributable to aberrant autonomic signaling. Further cardiographic studies of human SMA patients are needed to clarify the clinical relevance of these findings from this SMA mouse.

Increasing survival of motor neuron 2, centromeric (SMN2) exon 7 inclusion to express more full-length SMN protein in motor neurons is a promising approach to treat spinal muscular atrophy (SMA), a genetic neurodegenerative disease. Previously, we identified a potent 2'-O-(2-methoxyethyl) (MOE) phosphorothioate-modified antisense oligonucleotide (ASO) that blocks an SMN2 intronic splicing silencer element and efficiently promotes exon 7 inclusion in transgenic mouse peripheral tissues after systemic administration. Here we address its efficacy in the spinal cord-a prerequisite for disease treatment-and its ability to rescue a mild SMA mouse model that develops tail and ear necrosis, resembling the distal tissue necrosis reported in some SMA infants. Using a micro-osmotic pump, we directly infused the ASO into a lateral cerebral ventricle in adult mice expressing a human SMN2 transgene; the ASO gave a robust and long-lasting increase in SMN2 exon 7 inclusion measured at both the mRNA and protein levels in spinal cord motor neurons. A single embryonic or neonatal intracerebroventricular ASO injection strikingly rescued the tail and ear necrosis in SMA mice. We conclude that this MOE ASO is a promising drug candidate for SMA therapy, and, more generally, that ASOs can be used to efficiently redirect alternative splicing of target genes in the CNS.

Human embryonic stem cells provide a useful source of material for studying basic human development and various disease states. However, ethical issues concerning their procurement limit their acceptance and possible clinical applicability. Recent advances in stem cell technology have provided an alternative source of pluripotent stem cells that does not require the use of an embryo. This review addresses the generation of induced pluripotent stem cells from skin fibroblasts taken from various patient populations, with a specific focus on the pediatric disorder spinal muscular atrophy. These patient-derived cells may help researchers devise more appropriate therapies through a greater understanding of the molecular mechanisms that underlie neuron dysfunction and death in a variety of diseases. Furthermore, they provide an ideal platform for small-molecule screening and subsequent drug development.

Spinal muscular atrophy (SMA) is a common autosomal-recessive neuromuscular disorder caused by mutations in the survival motor neuron (SMN1) gene, affecting approximately 1 in 10,000 live births. The disease is characterized by progressive symmetric muscle weakness resulting from the degeneration and loss of anterior horn cells in the spinal cord and brainstem nuclei. The management of SMA involves supportive and preventive strategies. New treatments based on increasing the expression of full-length SMN protein levels from the SMN2 gene are being investigated and may be dependent on early detection of the disorder, before the irreversible loss of motor neurons. This article focuses on the prevention of SMA through population carrier screening and newborn screening as a means of ensuring early intervention for SMA.

Proximal spinal muscular atrophy (SMA) is the predominant form of motor neuron disease in children and young adults. In contrast to other neurodegenerative disorders, SMA is a genetically homozygous autosomal recessive disease that is caused by deficiency of the survival motor neuron (SMN) protein. This homogeneity should in principle facilitate therapy development. Previous therapy approaches have focused on upregulation of SMN expression from a second SMN (SMN2) gene that gives rise to low amounts of functional SMN protein. Drug development to target disease-specific mechanisms at cellular and physiological levels is in its early stages, as the pathophysiological processes that underlie the main disease symptoms are still not fully understood. Mouse models have helped to make conceptual progress in the disease mechanism, but their suitability in the search for therapeutic agents remains to be validated-an issue that is ubiquitous to the translational therapeutic research of other neurodegenerative diseases. Human induced pluripotent stem cell technology for generation of large numbers of human motor neurons could help to fill this gap and advance the power of drug screening. In parallel, advances in oligonucleotide technologies for engineering SMN2 pre-mRNA splicing are approaching their first clinical trials, whose success depends on improved technologies for drug delivery to motor neurons. If this obstacle can be overcome, this could boost therapy development, not only for SMA but also for other neurodegenerative disorders.

Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder caused by mutations in the survival motor neuron (SMN1) gene, affecting approximately 1 in 10,000 live births. The homozygous absence of SMN1 exon 7 has been observed in the majority of patients and is being utilized as a reliable and sensitive SMA diagnostic test. Treatment and prevention of SMA are complementary responses to the challenges presented by SMA. Even though a specific therapy for SMA is not currently available, a newborn screening test may allow the child to be enrolled in a clinical trial before irreversible neuronal loss occurs and enable patients to obtain more proactive treatments. Until an effective treatment is found to cure or arrest the progression of the disease, prevention of new cases through accurate diagnosis and carrier and prenatal diagnosis is of the utmost importance. The goal of population-based SMA carrier screening is to identify couples at risk for having a child with SMA, thus allowing carriers to make informed reproductive choices. During this study we performed two pilot projects addressing the clinical applicability of testing in the newborn period and carrier screening in the general population. We have demonstrated that an effective technology does exist for newborn screening of SMA. We also provide an estimate of the carrier frequency among individuals who accepted carrier screening, and report on patient's knowledge and attitudes toward SMA testing. (c) 2010 Wiley-Liss, Inc.

Valproate is commonly used as an anti-convulsant and mood stabilizer, but its long-term side-effects can include bone loss. As a histone deacetylase (HDAC) inhibitor, valproate has also been considered for treatment of spinal muscular atrophy (SMA). Using iTRAQ labeling technology, followed by two-dimensional liquid chromatography and mass spectrometry analysis, a quantitative comparison of the proteome of an SMA cell line, with and without valproate treatment, was performed. The most striking change was a reduction in collagens I and VI, while over 1,000 other proteins remained unchanged. The collagen I alpha-chain precursor was also reduced by more than 50% suggesting that valproate affects collagen I synthesis. The collagen-binding glycoprotein, osteonectin (SPARC, BM-40) was one of the few other proteins that were significantly reduced by valproate treatment. Collagen I is the main protein component of bone matrix and osteonectin has a major role in bone development, so the results suggest a possible molecular mechanism for bone loss following long-term exposure to valproate. SMA patients may already suffer bone weakness as a result of SMN1 gene deletion, so further bone loss would be undesirable.

Background Spinal muscular atrophy (SMA) is caused by the homozygous deletion of the survival motor neuron (SMN)1 gene. The nearly identical SMN2 gene produces small amounts of full-length mRNA and functional SMN protein, due to a point mutation in a critical splicing site. Increasing SMN protein production by histone deacetylase inhibiting drugs such as valproic acid (VPA) is an experimental treatment strategy for SMA. Objective To investigate whether an SMN-specific ELISA could detect changes in SMN protein expression in peripheral blood mononuclear cells (PBMCs) after treatment with VPA. Methods The authors developed a sensitive SMN-specific ELISA. Six patients with SMA types 2 and 3 participated in the study. Recombinant SMN calibration curves were used to calculate SMN protein levels in PBMCs before and after 4 months of VPA treatment. Results The SMN ELISA was able to detect small differences in SMN protein concentrations, and differences in SMN protein levels in Epstein-Barr virus immortalised lymphocyte cell lines from SMA type 1 and 2 patients, carriers and healthy individuals (p<0.05). The mean SMN protein level in PBMCs from SMA patients was 22% (SD 15%) of the value in a healthy control. VPA treatment resulted in significantly increased SMN protein levels in five out of six SMA patients compared with baseline values (p<0.05), but did not restore SMN levels to normal values. Conclusions SMN protein quantification by this SMN ELISA is a useful additional tool for evaluating the effects of experimental treatment in SMA.

Spinal muscular atrophy is one of the most common genetic causes of death in childhood, and there is currently no effective treatment. The disease is caused by mutations in the survival motor neuron gene. Gene therapy aimed at restoring the protein encoded by this gene is a rational therapeutic approach to ameliorate the disease phenotype. We previously reported that intramuscular delivery of a lentiviral vector expressing survival motor neuron increased the life expectancy of transgenic mice with spinal muscular atrophy. The marginal efficacy of this therapeutic approach, however, prompted us to explore different strategies for gene therapy delivery to motor neurons to achieve a more clinically relevant effect. Here, we report that a single injection of self-complementary adeno-associated virus serotype 9 expressing green fluorescent protein or of a codon-optimized version of the survival motor neuron protein into the facial vein 1 day after birth in mice carrying a defective survival motor neuron gene led to widespread gene transfer. Furthermore, this gene therapy resulted in a substantial extension of life span in these animals. These data demonstrate a significant increase in survival in a mouse model of spinal muscular atrophy and provide evidence for effective therapy.

PTEN (phosphatase and tensin homolog), a negative regulator of the target of rapamycin (mTOR) pathway, is widely involved in regulation of protein synthesis. Here we show that the PTEN protein is enriched in cell bodies and axon terminals of purified motor neurons. We explored the role of the PTEN pathway by manipulating PTEN expression in healthy and diseased motor neurons. PTEN depletion led to an increase in growth cones size, promotion of axonal elongation and increased survival of these cells. These changes were associated with alterations of downstream signalling pathways for local protein synthesis as revealed by an increase in pAKT and p70S6. Most notably, this treatment also restores ss-actin protein levels in axonal growth cones of SMN deficient motor neurons. Furthermore, we report here that a single injection of adeno-associated virus serotype 6 (AAV6) expressing siPTEN into hind limb muscles at postnatal day 1 in SMNDelta7 mice leads to significant PTEN depletion and robust improvement in motor neuron survival. Taken together these data indicate that PTEN mediated regulation of protein synthesis in motor neurons could represent a target for therapy in spinal muscular atrophy.

Recent analyses of complete genomes have revealed that alternative splicing became more prevalent and important during eukaryotic evolution. Alternative splicing augments the protein repertoire-particularly that of the human genome-and plays an important role in the development and function of differentiated cell types. However, splicing is also extremely vulnerable, and defects in the proper recognition of splicing signals can give rise to a variety of diseases. In this review, we discuss splicing correction therapies, by using the inherited disease Spinal Muscular Atrophy (SMA) as an example. This lethal early childhood disorder is caused by deletions or other severe mutations of SMN1, a gene coding for the essential survival of motoneurons protein. A second gene copy present in humans and few non-human primates, SMN2, can only partly compensate for the defect because of a single nucleotide change in exon 7 that causes this exon to be skipped in the majority of mRNAs. Thus SMN2 is a prime therapeutic target for SMA. In recent years, several strategies based on small molecule drugs, antisense oligonucleotides or in vivo expressed RNAs have been developed that allow a correction of SMN2 splicing. For some of these, a therapeutic benefit has been demonstrated in mouse models for SMA. This means that clinical trials of such splicing therapies for SMA may become possible in the near future.

Proximal spinal muscular atrophy (SMA) is a neuromuscular disease caused by low levels of the survival motor neuron (SMN) protein. The reduced SMN levels are due to loss of the survival motor neuron-1 (SMN1) gene. Humans carry a nearly identical SMN2 gene that generates a truncated protein, due to a C to T nucleotide alteration in exon 7 that leads to inefficient RNA splicing of exon 7. This exclusion of SMN exon 7 is central to the onset of the SMA disease, however, this offers a unique therapeutic intervention in which corrective splicing of the SMN2 gene would restore SMN function. Exon 7 splicing is regulated by a number of exonic and intronic splicing regulatory sequences and trans-factors that bind them. A better understanding of the way SMN pre-mRNA is spliced has lead to the development of targeted therapies aimed at correcting SMN2 splicing. As therapeutics targeted toward correction of SMN2 splicing continue to be developed available SMA mouse models can be utilized in validating their potential in disease treatment.

Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is a calcium-permeable nonselective cation channel of unknown biological function. TRPV4 mutation was first identified in brachyolmia, and then in a spectrum of autosomal-dominant skeletal dysplasias, which includes Kozlowski type of spondylometaphyseal dysplasia, metatropic dysplasia, Maroteaux type of spondyloepiphyseal dysplasia and parastremmatic dysplasia. Recently, TRPV4 mutation has also been identified in a spectrum of neuromuscular diseases that includes congenital distal spinal muscular atrophy (SMA), scapuloperoneal SMA, and hereditary motor and sensory neuropathy type IIC. These diverse spectrums of diseases compose a novel channelopathy, TRPV4-pathy, which could further include polygenic traits such as serum sodium concentration and a chronic obstructive pulmonary disease. In this review, we clarified the TRPV4 mutation spectrum, and discussed the phenotypic complexity of TRPV4-pathy and its pathogenic mechanisms. TRPV4-pathy may extend further to other monogenic and polygenic diseases.Journal of Human Genetics advance online publication, 27 May 2010; doi:10.1038/jhg.2010.37.

Abstract: The goal of this study was to create a new model of motor neuron (MN) loss. We mimicked the cellular deficit and loss of function by damaging the sciatic nerve with an injection of the toxic lectin Ricinus communis agglutinin I (RCA I or ricin). Since the sciatic nerve supplies movement to most of the lower limb, damaging this motor system models lower limb paralysis and the deficits that occur in diseases like amyotrophic lateral sclerosis (ALS) and infantile progressive spinal muscular atrophy (SMA). We used motor, sensory-motor, locomotor and reflex-based tests to demonstrate loss of function after ricin injection. Loss of function was also demonstrated by decreased retrograde transport, and supported by measurements of muscle wasting. Histochemical and molecular methods were used to characterize sciatic nerve damage in axons and cell bodies, including apoptotic cell death in MNs. This battery of tests documents the extent of the ricin-induced damage and provides a baseline that can be used to judge the efficacy of MN treatment strategies in preclinical studies.

OBJECTIVE: To measure muscle strength in patients with spinal muscular atrophy using a handheld dynamometer as an objective tool to evaluate the progression of disease and the outcome of therapeutic trials. DESIGN: Maximum voluntary isometric contraction was measured in a group of 24 patients aged 5-38 years with types II and III spinal muscular atrophy. Four muscle groups were examined. Data were grouped according to age and sex. Comparison was made between spinal muscular atrophy types; ambulatory vs non-ambulatory, and survival motor neuron (SMN)2 copies. The results were compared with those of a healthy reference population. RESULTS: Muscle strength was much lower in patients with spinal muscular atrophy than in the healthy population. The walkers group yielded higher values than patients who were non-walkers. Knee extensors were the weakest muscles in both groups, regardless of the ability to walk. The greatest differences were found between ambulatory and non-ambulatory patients. Non-walkers type III patients showed lower values, similar to those for type II patients. Patients with 3 and 4 SMN2 copies showed higher strength with respect to those with 2 SMN2 copies, although not statistically significant. CONCLUSION: The handheld dynamometer is a valid tool for measuring muscle strength in patients with spinal muscular atrophy. It can be used to measure disease progression and to evaluate changes in therapeutic trials.

Spinal and bulbar muscular atrophy (SBMA) is an hereditary, adult-onset, lower motor neuron disease caused by an aberrant elongation of a trinucleotide CAG repeat, which encodes the polyglutamine tract, in the first exon of the androgen receptor (AR) gene. The main symptoms are slowly progressive muscle weakness and atrophy of bulbar, facial and limb muscles. The cardinal histopathological findings of SBMA are an extensive loss of lower motor neurons in the anterior horn of the spinal cord as well as in brainstem motor nuclei and intranuclear accumulations of mutant AR protein in the residual motor neurons. Androgen deprivation therapy rescues neuronal dysfunction in animal models of SBMA, suggesting that the molecular basis for motor neuron degeneration in this disorder is testosterone-dependent nuclear accumulation of the mutant AR. Suppression of disease progression by leuprorelin acetate has also been demonstrated in a phase 2 clinical trial. In addition, the clarification of pathophysiology leads to appearance of candidate drugs to treat this devastating disease: heat shock protein (HSP) inducer, Hsp90 inhibitor, and histone deacetylase inhibitor. Advances in basic and clinical research on SBMA are now paving the way for clinical application of pathogenesis-targeting therapeutics.

Spinal Muscular Atrophy (SMA) is an autosomal recessive neurodegenerative disorder and a leading genetic cause of infantile mortality. SMA is caused by mutation or deletion of Survival Motor Neuron-1 (SMN1). The clinical features of the disease are caused by specific degeneration of alpha-motor neurons in the spinal cord, leading to muscle weakness, atrophy, and in the majority of cases to premature death. A highly homologous copy gene (SMN2) is retained in almost all SMA patients but fails to generate adequate levels of SMN protein due to its defective splicing pattern. The severity of the SMA phenotype is inversely correlated with SMN2 copy number and the level of full-length SMN protein produced by SMN2 (approximately 10-15% compared to SMN1). The natural history of SMA has been altered over the past several decades, primarily through supportive care measures, but an effective treatment does not presently exist. However, the common genetic etiology and recent progress in preclinical models suggest that SMA is well-suited for the development of therapeutic regimens. We summarize recent advances in translational research that hold promise for the progression towards clinical trials.

INTRODUCTION: Fractures are a common problem for patients with spinal muscular atrophy (SMA). PATIENTS: A total of 131 patients with proximal SMA with an average age of 13.2 +/- 9.2 years (0.7-65.6) were evaluated retrospectively. In 60 patients 94 different fractures were observed. The group consisted of 11 patients with type Ib, 81 with type II, 33 with type IIIa, 4 with IIIb and 2 with type IV. 38 of 81 SMA II patients and 17 of 33 SMA IIIa patients had suffered fractures at an average age of 8.3 +/- 5.3 years (0.0-25.1) (SMA II) and 9.3 +/- 6.0 years (0.0-22.1) (SMA IIIa). RESULTS: The most frequent fractures were of the femur (50), usually distal, of the lower leg and ankle (15), and upper arm (9). The distribution of fractures was different in SMA II and SMA IIIa. Most of the fractures could be treated conservatively. Only two femoral shaft fractures, one upper arm and a lower arm fracture were treated surgically by osteosynthesis. CONCLUSION: Competent fracture treatment is an important part of the orthopaedic care of SMA patients.

Spinal muscular atrophy (SMA) is an autosomal recessive disorder that affects motor neurons. It is caused by mutations in the survival motor neuron gene 1 (SMN1). The SMN2 gene, which is the highly homologous SMN1 copy that is present in all patients, is unable to prevent the disease. SMA patients can be classified into four groups based on age at onset and acquired milestones (type I or severe acute disease, with onset before 6 months; type II, before 18 months; type III, after 18 months and type IV, in adult life). The human developmental period is believed to play an essential role in SMA pathogenesis. However, the neuropathologic study of SMA comes largely from postnatal necropsy samples, which describe the end-stage of the disease. With the exception of severe congenital SMA (or Type 0 SMA), type I patients tend to present a short but variable presymptomatic period after birth. Our main interest lies in studying SMA during human development so as to gain insight into the mechanism of the disease in the prenatal-presymptomatic stage. In fetuses of 12-15 weeks' gestational age we systematically studied histology, cell death and gene expression in spinal cord and muscle, the key tissues involved in the disease. Furthermore, ultrasound parameters were investigated at these stages. These studies may help to delineate an early intervention in SMA, in particular during the potential therapeutic window.

The literature has described different indications for pelvic fixation in neuromuscular scoliosis. We retrospectively evaluated changes in pelvic obliquity for a minimum of two years among three groups: group I (initial pelvic obliquity >15 degrees; with pelvic fixation), group II (initial pelvic obliquity >15 degrees; without pelvic fixation), and group III (initial pelvic obliquity <15 degrees; without pelvic fixation). We used iliac screws for pelvic fixation in group I. There was significant postoperative improvement (p < 0.0001) in Cobb's angle and pelvic obliquity. There was no significant loss of correction in Cobb's angle, thoracic kyphosis, and lumbar lordosis among all three groups; however, group II showed significant correction loss in pelvic obliquity compared to groups I and III at final follow-up (p < 0.0001). Our results indicate that patients who have pelvic obliquity >15 degrees require pelvic fixation to maintain the correction and balance over time while obliquity <15 degrees does not require pelvic fixation.

Neuromuscular diseases (NMD), including Spinal Muscular Atrophy (SMA) and Duchenne Muscular Dystrophy (DMD), result in progressive muscular weakness that often leaves patients functionally dependent on caregivers for many activities of daily living (ADL) such as eating, bathing, grooming (touching the face and head), reaching (grabbing for objects), and dressing. In severe cases, patients are unable to perform even the simplest of activities from exploring their 3D space to touching their own face. The ability to move and initiate age appropriate tasks, such as playing and exploration, are considered to be of vital importance to both their physical and cognitive development. Therefore, to improve quality of life and reduce dependence on caregivers in children and young adults with NMD, we designed, built and evaluated an assistive, active orthosis to support arm function. The goal of this project is the development and evaluation of a mechanical arm orthosis to both encourage and assist functional arm movement while providing the user a sense of independence and control over one's own body.

Currently, there is no cure for the treatment of spinal muscular atrophy (SMA). Based on the available clinical and molecular findings, different therapeutic strategies were tested in vitro and in vivo and clinical trials are ongoing. The main therapeutic direction is focused on the enhancement of SMN expression by increasing the full-length (fl) SMN2 transcript levels, preventing the SMN exon 7 from skipping or from protein stabilizing. In addition, the action of neurotrophic, neuroprotective or anabolic agents is tested and stem cell and gene therapy approaches are in a promising development.

BACKGROUND: Spinal Muscular Atrophy (SMA) is an autosomal recessive disease that leads to specific loss of motor neurons. It is caused by deletions or mutations of the survival of motor neuron 1 gene (SMN1). The remaining copy of the gene, SMN2, generates only low levels of the SMN protein due to a mutation in SMN2 exon 7 that leads to exon skipping. METHODOLOGY/PRINCIPAL FINDINGS: To correct SMN2 splicing, we use Adenovirus type 5-derived vectors to express SMN2-antisense U7 snRNA oligonucleotides targeting the SMN intron 7/exon 8 junction. Infection of SMA type I-derived patient fibroblasts with these vectors resulted in increased levels of exon 7 inclusion, upregulating the expression of SMN to similar levels as in non-SMA control cells. CONCLUSIONS/SIGNIFICANCE: These results show that Adenovirus type 5-derived vectors delivering U7 antisense oligonucleotides can efficiently restore full-length SMN protein and suggest that the viral vector-mediated oligonucleotide application may be a suitable therapeutic approach to counteract SMA.

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by a deficiency of survival motor neuron (SMN) due to mutations in the SMN1 gene. In this study, an adeno-associated virus (AAV) vector expressing human SMN (AAV8-hSMN) was injected at birth into the CNS of mice modeling SMA. Western blot analysis showed that these injections resulted in widespread expression of SMN throughout the spinal cord, and this translated into robust improvement in skeletal muscle physiology, including increased myofiber size and improved neuromuscular junction architecture. Treated mice also displayed substantial improvements on behavioral tests of muscle strength, coordination, and locomotion, indicating that the neuromuscular junction was functional. Treatment with AAV8-hSMN increased the median life span of mice with SMA-like disease to 50 days compared with 15 days for untreated controls. Moreover, injecting mice with SMA-like disease with a human SMN-expressing self-complementary AAV vector - a vector that leads to earlier onset of gene expression compared with standard AAV vectors - led to improved efficacy of gene therapy, including a substantial extension in median survival to 157 days. These data indicate that CNS-directed, AAV-mediated SMN augmentation is highly efficacious in addressing both neuronal and muscular pathologies in a severe mouse model of SMA.

OBJECTIVE: To study conditions of living, participation and diagnostic perceptions in a national population of adult persons with spinal muscular atrophy type 2 (SMA 2). METHODS: A mixed method design combining cross-sectional survey data with personal narratives was chosen. Twenty-nine of 37 patients with SMA 2 aged >or=18 years participated in a semi-structured questionnaire survey and three were selected for in-depth journalistic interviews. Socioeconomic data, activities and personal significance of problems were calculated. Journalistic stories were analysed for constructs of personal diagnostic qualities. RESULTS: Everyone was actively directing their life despite being heavily dependent. Deterioration of physical abilities was a major concern for women. Seventy-six per cent were single, but stated their quality of life as fine. Narratives of living with SMA 2 were associated with positive characteristics, as opposed to the medical diagnostic wording. CONCLUSION: Female coping needs more research. Narrative method complements medical knowledge.

Spinal muscular atrophy, characterized by selective loss of lower motor neurons, is an incurable genetic neurological disease leading to infant mortality. We previously showed that primary neural stem cells derived from spinal cord can ameliorate the spinal muscular atrophy phenotype in mice, but this primary source has limited translational value. Here, we illustrate that pluripotent stem cells from embryonic stem cells show the same potential therapeutic effects as those derived from spinal cord and offer great promise as an unlimited source of neural stem cells for transplantation. We found that embryonic stem cell-derived neural stem cells can differentiate into motor neurons in vitro and in vivo. In addition, following their intrathecal transplantation into spinal muscular atrophy mice, the neural stem cells, like those derived from spinal cord, survived and migrated to appropriate areas, ameliorated behavioural endpoints and lifespan, and exhibited neuroprotective capability. Neural stem cells obtained using a drug-selectable embryonic stem cell line yielded the greatest improvements. As with cells originating from primary tissue, the embryonic stem cell-derived neural stem cells integrated appropriately into the parenchyma, expressing neuron- and motor neuron-specific markers. Our results suggest translational potential for the use of pluripotent cells in neural stem cell-mediated therapies and highlight potential safety improvements and benefits of drug selection for neuroepithelial cells.

OBJECTIVE: To discuss the diagnosis of spinal muscular atrophy in a child conceived using donor gametes. DESIGN: None. SETTING: None. PATIENT(S): Offspring of gamete donors. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): None. RESULT(S): A child conceived using gametes from anonymous sperm and ova donors was diagnosed with spinal muscular atrophy type 1. CONCLUSION(S): Gamete donor facilities are not required to perform extensive genetic testing on their donors; however, the well-being of the children conceived through assisted reproductive technologies should be a primary objective of reproductive medicine. The risk for specific medical problems in donor offspring can be significantly reduced by incorporating carrier screening for common, severe disorders such as spinal muscular atrophy into donor screening practices. Future efforts should focus on communicating the limitations of genetic screening to donor gamete recipients and educating them about their reproductive options.

Proximal spinal muscular atrophy (SMA) is a leading genetic cause of infant death. Patients with SMA lose alpha-motor neurons in the ventral horn of the spinal cord which leads to skeletal muscle weakness and atrophy. SMA is the result of reduction in Survival Motor Neuron (SMN) expression. Transgenic mouse models of SMA have been generated and are extremely useful in understanding the mechanisms of motor neuron degeneration in SMA and in developing new therapeutic candidates for SMA patients. Several research groups have reported varying average lifespans of SMNDelta7 SMA mice (SMN2(+/+);SMNDelta7(+/+);mSmn(-/-)), the most commonly used mouse model for preclinical therapeutic candidate testing. One environmental factor that varied between research groups was maternal diet. In this study, we compared the effects of two different commercially available rodent chows (PicoLab20 Mouse diet and Harlan-Teklad 22/5 diet) on the survival and motor phenotype of the SMNDelta7 mouse model of SMA. Specifically, the PicoLab20 diet significantly extends the average lifespan of the SMNDelta7 SMA mice by approximately 25% and improved the motor phenotype as compared to the Harlan diet. These findings indicate that maternal diet alone can have considerable impact on the SMA phenotype.

OBJECTIVE:: To evaluate the reliability and validity of the PedsQL 3.0 Neuromuscular Module (NMM) in assessing health-related quality of life in the Duchenne muscular dystrophy (DMD) population for use as a secondary outcome measure in phase III clinical trials. BACKGROUND:: DMD is the most common genetic form of muscular dystrophy in childhood. Clinical trials are underway to evaluate modalities of treatment. The NMM was developed based on interviews of patients with DMD and spinal muscular atrophy. To determine the PedsQL reliability and validity, we administered the NMM to patients with DMD and their caregivers. DESIGN/METHODS:: Boys 8 to 18 years old with DMD were recruited from a neuromuscular disease clinic. At baseline, the child and caregiver completed the NMM and the PedsQL 4.0 Generic Core Scales (GC). The NMM was repeated 2 to 6 weeks later. Reliability was assessed using Cronbach's coefficient alpha (internal consistency) and intraclass correlation (ICC) (test-retest consistency). Construct validity was assessed by comparing baseline child and caregiver NMM total scores with the GC Total Score, forced vital capacity, cardiac ejection fraction, and ambulatory status. RESULTS:: Forty-four children and their caregivers completed the study. Internal consistency reliability of the total scale score of the NMM was demonstrated (Child alpha = 0.85; Caregiver alpha = 0.87). Test-retest reliability of the NMM was also demonstrated (Child ICC = 0.75, P = 0.001; Caregiver ICC = 0.85, P < 0.001). Validity of the total scale score of the NMM when compared with the GC Total Scale Score was supported (Child r (41) = 0.63, P < 0.001; Caregiver r (42) = 0.64, P < 0.001). Validity of the NMM compared with forced vital capacity was also supported (Child r (38) = 0.35, P = 0.032; Caregiver r (39) = 0.41, P = 0.01). The NMM parent-proxy-report and child self-report "About My Child's Neuromuscular Disease" scale was significantly related to wheelchair use (P < 0.008 and 0.016, respectively); the GC "Child Self-Report "Physical Health" scale was also significantly related to wheelchair use (P < 0.001). We were unable to conduct any analysis with ejection fraction because of the small number of children across all categories. CONCLUSIONS:: The PedsQL NMM is a reliable measure of disease-specific health-related quality of life in the DMD population and may be used as an outcome measure in clinical trials.

Retrograde transport of viral vectors in the rodent spinal cord provides a powerful means to administer a therapeutic transgene from the innervated musculature. With the aim of scaling up this approach to non-human primates, we have injected recombinant adeno-associated vectors (rAAV) serotype 6 expressing enhanced green fluorescent protein (eGFP) into the gastrocnemius muscle of African green monkeys to determine whether this results in efficient transgene delivery to lumbar motor neurons. Cells expressing eGFP were observed across more than 1 cm of the spinal cord 4 weeks after intramuscular injection, reaching more than half of motor neurons in some cross-sections. Furthermore, quantitative PCR on the spinal cord tissue confirmed that eGFP expression within motor neurons was due to bona fide retrograde transport of the vector genome from the muscle. Although infiltrations of macrophages and lymphocytes were observed in the rAAV2/6-injected muscle, there was no detectable immune response within the transduced region of the spinal cord. These findings imply that retrograde delivery of rAAV serotype 6 in a primate species constitutes a non-invasive and robust approach to transduce motor neurons, a crucial target cell population in neurodegenerative disorders, such as amyotrophic lateral sclerosis and spinal muscular atrophy.

Neurodegenerative disorders (NDs) such as Huntington's disease, Alzheimer's disease, Parkinson disease, amyotrophic lateral sclerosis, spinal muscular atrophy, Friedreich's ataxia, and others are multi-factorial illnesses, in which many pathways (still poorly understood) act serially and in parallel to give a determined pathologic phenotype. Thus, presently there are no effective cures for these diseases. Some phenotypic as well as mechanistic features, common to the most of NDs, can be linked to epigenetic defects, that can lead to alteration of acetylation homeostasis and impairment of the histone acetyltransferase (HAT): histone deacetylase (HDAC) balance. Here we survey most of the recent applications of HDAC inhibitors in the cited NDs, and we make the point of our (up to now) knowledge about the involvement of singular HDAC/SIRT isoform in NDs and other CNS pathologies.

BACKGROUND: Scoliosis is a frequent complication of pediatric neuromuscular disease (NMD). Scoliosis surgery in children with NMD is thought to carry greater morbidity and mortality. OBJECTIVES: To study demographics, comorbidities, outcomes, and hospitalization expenditures among children with NMD undergoing scoliosis surgery. DESIGN: Using the Kids Inpatient Database, a large all-payer US database of hospital discharges among children and adults younger than 20 years, we studied children undergoing scoliosis surgery between January 1, 1997, and December 31, 2003. Continuous variables were compared by t test, and categorical variables were compared by Pearson product moment correlation chi(2) test. SETTING: National database of pediatric hospital discharges. PATIENTS: Children with and without NMD. MAIN OUTCOME MEASURES: Demographics, hospital length of stay, and in-hospital mortality associated with scoliosis surgery. RESULTS: Of 17 780 reported hospitalizations owing to scoliosis surgery, 437 children (2.5%) had NMD. Compared with children undergoing scoliosis surgery for other indications, children with NMD were more likely to be younger (12.4 vs 14.2 years), male (73.5% vs 38.3%), and insured by Medicaid (35.6% vs 20.3%). Comorbidities that were more common among children with NMD included pulmonary complications (lung disease not classified, pulmonary collapse, pulmonary insufficiency, chronic respiratory failure, and ventilator requirement) and cardiovascular complications (cardiomyopathy, hypotension, and tachycardia). Scoliosis surgery in children with NMD was associated with increased hospital length of stay (10.3 vs 7.7 days) and hospitalization expenditures ($80 251 vs $62 154), and higher in-hospital mortality (1.6% vs 0.2%). CONCLUSION: Children with NMD have increased hospital length of stay and higher in-hospital mortality associated with scoliosis surgery, highlighting the need for further study of measures that could reduce complications and improve outcomes in this population.

Spinal muscular atrophy (SMA) is caused by homozygous survival of motor neurons 1 (SMN1) gene deletions, leaving a duplicate gene, SMN2, as the sole source of SMN protein. However, most of the mRNA produced from SMN2 pre-mRNA is exon 7-skipped ( approximately 80%), resulting in a highly unstable and almost undetectable protein (SMNDelta7). We show that this splicing defect creates a potent degradation signal (degron; SMNDelta7-DEG) at SMNDelta7's C-terminal 15 amino acids. The S270A mutation inactivates SMNDelta7-DEG, generating a stable SMNDelta7 that rescues viability of SMN-deleted cells. These findings explain a key aspect of the SMA disease mechanism, and suggest new treatment approaches based on interference with SMNDelta7-DEG activity.

Spinal muscular atrophy (SMA), the most common autosomal recessive neurodegenerative disease affecting children, results in impaired motor neuron function. Despite knowledge of the pathogenic role of decreased survival motor neuron (SMN) protein levels, efforts to increase SMN have not resulted in a treatment for patients. We recently demonstrated that self-complementary adeno-associated virus 9 (scAAV9) can infect approximately 60% of motor neurons when injected intravenously into neonatal mice. Here we use scAAV9-mediated postnatal day 1 vascular gene delivery to replace SMN in SMA pups and rescue motor function, neuromuscular physiology and life span. Treatment on postnatal day 5 results in partial correction, whereas postnatal day 10 treatment has little effect, suggesting a developmental period in which scAAV9 therapy has maximal benefit. Notably, we also show extensive scAAV9-mediated motor neuron transduction after injection into a newborn cynomolgus macaque. This demonstration that scAAV9 traverses the blood-brain barrier in a nonhuman primate emphasizes the clinical potential of scAAV9 gene therapy for SMA.

This document, approved by the Rehabilitation Engineering & Assistive Technology Society of North America (RESNA) Board of Directors in March 2007, shares typical clinical applications and provides evidence from the literature supporting the use of power wheelchairs for children.

There is at present no cure or effective therapy for spinal muscular atrophy (SMA), a neurodegenerative disease that is the leading genetic cause of infant mortality. SMA usually results from loss of the SMN1 (survival of motor neuron 1) gene, which leads to selective motor neuron degeneration. SMN2 is nearly identical to SMN1 but has a nucleotide replacement that causes exon 7 skipping, resulting in a truncated, unstable version of the SMA protein. SMN2 is present in all SMA patients, and correcting SMN2 splicing is a promising approach for SMA therapy. We identified a tetracycline-like compound, PTK-SMA1, which stimulates exon 7 splicing and increases SMN protein levels in vitro and in vivo in mice. Unlike previously identified molecules that stimulate SMN production via SMN2 promoter activation or undefined mechanisms, PTK-SMA1 is a unique therapeutic candidate in that it acts by directly stimulating splicing of exon 7. Synthetic small-molecule compounds such as PTK-SMA1 offer an alternative to antisense oligonucleotide therapies that are being developed as therapeutics for a number of disease-associated splicing defects.

A number of missense mutations in the two related small heat shock proteins HspB8 (Hsp22) and HspB1 (Hsp27) have been associated with the inherited motor neuron diseases (MND) distal hereditary motor neuropathy and Charcot-Marie-Tooth disease. HspB8 and HspB1 interact with each other, suggesting that these two etiologic factors may act through a common biochemical mechanism. However, their role in neuron biology and in MND is not understood. In a yeast two-hybrid screen, we identified the DEAD box protein Ddx20 (gemin3, DP103) as interacting partner of HspB8. Using co-immunoprecipitation, chemical cross-linking, and in vivo quantitative fluorescence resonance energy transfer, we confirmed this interaction. We also show that the two disease-associated mutant HspB8 forms have abnormally increased binding to Ddx20. Ddx20 itself binds to the survival-of-motor-neurons protein (SMN protein), and mutations in the SMN1 gene cause spinal muscular atrophy, another MND and one of the most prevalent genetic causes of infant mortality. Thus, these protein interaction data have linked the three etiologic factors HspB8, HspB1, and SMN protein, and mutations in any of their genes cause the various forms of MND. Ddx20 and SMN protein are involved in spliceosome assembly and pre-mRNA processing. RNase treatment affected the interaction of the mutant HspB8 with Ddx20 suggesting RNA involvement in this interaction and a potential role of HspB8 in ribonucleoprotein processing.

Splice-modulation therapy, whereby molecular manipulation of premessenger RNA splicing is engineered to yield genetic correction, is a promising novel therapy for genetic diseases of muscle and nerve-the prototypical example being Duchenne muscular dystrophy. Duchenne muscular dystrophy is the most common childhood genetic disease, affecting one in 3500 newborn boys, causing progressive muscle weakness, heart and respiratory failure and premature death. No cure exists for this disease and a number of promising new molecular therapies are being intensively studied. Duchenne muscular dystrophy arises due to mutations that disrupt the open-reading-frame in the DMD gene leading to the absence of the essential muscle protein dystrophin. Of all novel molecular interventions currently being investigated for Duchenne muscular dystrophy, perhaps the most promising method aiming to restore dystrophin expression to diseased cells is known as 'exon skipping' or splice-modulation, whereby antisense oligonucleotides eliminate the deleterious effects of DMD mutations by modulating dystrophin pre-messenger RNA splicing, such that functional dystrophin protein is produced. Recently this method was shown to be promising and safe in clinical trials both in The Netherlands and the UK. These trials studied direct antisense oligonucleotide injections into single peripheral lower limb muscles, whereas a viable therapy will need antisense oligonucleotides to be delivered systemically

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Trans-splicing-mediated improvement in a severe mouse model of spinal muscular atrophy.

J Neurosci. 2010 Jan 6;30(1):126-30

Authors: Coady TH, Lorson CL

Spinal muscular atrophy is a leading genetic cause of infantile death and occurs in approximately 1/6000 live births. SMA is caused by the loss of Survival Motor Neuron-1 (SMN1), however, all patients retain at least one copy of a nearly identical gene called SMN2. While SMN2 and SMN1 are comprised of identical coding sequences, the majority of SMN2 transcripts are alternatively spliced, encoding a truncated protein that is unstable and nonfunctional. Considerable effort has focused upon modulating the SMN2 alternative splicing event since this would produce more wild-type protein. Recently we reported the development of an optimized trans-splicing system that involved the coexpression of a SMN2 trans-splicing RNA and an antisense RNA that blocks a downstream splice site in SMN2 pre-mRNA. Here, we demonstrate that in vivo delivery of the optimized trans-splicing vector increases an important SMN-dependent activity, snRNP assembly, in disease-relevant tissue in the SMA mouse model. A single injection of the vector into the intracerebral-ventricular space in SMA neonates also lessens the severity of the SMA phenotype in a severe SMA mouse model, extending survival approximately 70%. Collectively, these results provide the first in vivo demonstration that SMN2 trans-splicing leads to a lessening of the severity of the SMA phenotype and provide evidence for the power of this strategy for reprogramming genetic diseases at the pre-mRNA level.

PMID: 20053895 [PubMed - indexed for MEDLINE]

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Treatment and complications in flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy) with posterior-only pedicle screw instrumentation.

Eur Spine J. 2009 Nov 3;

Authors: Modi HN, Suh SW, Hong JY, Cho JW, Park JH, Yang JH

Literature has described treatment of flaccid neuromuscular scoliosis using different instrumentation; however, only one article has been published using posterior-only pedicle screw fixation. Complications using pedicle screws in paralytic neuromuscular scoliosis has not been described before. To present results and complications with posterior-only pedicle screws, a retrospective study was carried out in 27 consecutive patients with flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy), who were operated between 2002 and 2006 using posterior-only pedicle screw instrumentation. Immediate postoperative and final follow-up results were compared using t test for Cobb angle, pelvic obliquity, thoracic kyphosis and lumbar lordosis. Perioperative and postoperative complications were noted from the hospital records of each patient. Complications, not described in literature, were discussed in detail. Average follow-up was 32.2 months. Preoperative, immediate postoperative and final follow-up Cobb angle were 79.8 degrees , 30.2 degrees (63.3% correction, p < 0.0001) and 31.9 degrees , respectively; and pelvic obliquity was 18.3 degrees , 8.9 degrees (52% correction, p < 0.0001) and 8.9 degrees . Postoperative thoracic kyphosis remained unchanged from 27.6 degrees to 19.9 degrees (p = 0.376); while lumbar lordosis improved significantly from +15.6 degrees to -22.4 degrees lordosis (p = 0.0002). Most patients had major to moderate improvement in postoperative functional and ambulatory status compared to the preoperative status. Thirteen (48.1%) perioperative complications were noted with five major complications (four respiratory in the form of hemothorax or respiratory failure that required ventilator support and one death) and eight minor complications (three UTI, two atelectasis, two neurological and one ileus). Postoperatively, we noted complications, such as coccygodynia with subluxation in 7, back sore on the convex side in 4 and dislodging of rod distally in 1 patient making a total of 12 (44.4%) postoperative complications. Of 12 postoperative complications, 6 (50%) required secondary procedure. We conclude that although flaccid neuromuscular scoliosis can be well corrected with posterior-only pedicle screw, there is a high rate of associated complications.

PMID: 19885687 [PubMed - as supplied by publisher]

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Possible JCV granular cell neuronopathy in a patient with HIV infection.

Neurology. 2009 Nov 10;73(19):1598-9

Authors: Tan IL, Brew BJ

PMID: 19901253 [PubMed - indexed for MEDLINE]

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Dysphagia in spinal muscular atrophy type II: more than a bulbar problem?

Neurology. 2009 Nov 24;73(21):1787-91

Authors: van den Engel-Hoek L, Erasmus CE, van Bruggen HW, de Swart BJ, Sie LT, Steenks MH, de Groot IJ

OBJECTIVE: In patients with spinal muscular atrophy (SMA) type II, feeding problems and dysphagia are common, but the underlying mechanisms of these problems are not well defined. This case control study was designed to determine the underlying mechanisms of dysphagia in SMA type II. METHODS: Six children with SMA type II and 6 healthy matched controls between 6.4 and 13.4 years of age were investigated during swallowing liquid and solid food in 2 different postures using surface EMG (sEMG) of the submental muscle group (SMG) and a video fluoroscopic swallow study (VFSS). RESULTS: The VFSS showed postswallow residue of solid food in the vallecula and above the upper esophageal sphincter (UES), which can be responsible for indirect aspiration. Better results in swallowing were achieved in a more forward head position. These findings were supported by the sEMG measurements of the SMG during swallowing. CONCLUSIONS: Dysphagia in spinal muscular atrophy type II is due to a neurologic dysfunction (lower motor neuron problems from the cranial nerves in the brainstem) influencing the muscle force and efficiency of movement of the tongue and the submental muscle group in combination with a biomechanical component (compensatory head posture). The results suggest an integrated treatment with an adapted posture during meals and the advice of drinking water after meals to prevent aspiration pneumonias.

PMID: 19933981 [PubMed - indexed for MEDLINE]

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Treatment and complications in flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy) with posterior-only pedicle screw instrumentation.

Eur Spine J. 2009 Nov 3;

Authors: Modi HN, Suh SW, Hong JY, Cho JW, Park JH, Yang JH

Literature has described treatment of flaccid neuromuscular scoliosis using different instrumentation; however, only one article has been published using posterior-only pedicle screw fixation. Complications using pedicle screws in paralytic neuromuscular scoliosis has not been described before. To present results and complications with posterior-only pedicle screws, a retrospective study was carried out in 27 consecutive patients with flaccid neuromuscular scoliosis (Duchenne muscular dystrophy and spinal muscular atrophy), who were operated between 2002 and 2006 using posterior-only pedicle screw instrumentation. Immediate postoperative and final follow-up results were compared using t test for Cobb angle, pelvic obliquity, thoracic kyphosis and lumbar lordosis. Perioperative and postoperative complications were noted from the hospital records of each patient. Complications, not described in literature, were discussed in detail. Average follow-up was 32.2 months. Preoperative, immediate postoperative and final follow-up Cobb angle were 79.8 degrees , 30.2 degrees (63.3% correction, p < 0.0001) and 31.9 degrees , respectively; and pelvic obliquity was 18.3 degrees , 8.9 degrees (52% correction, p < 0.0001) and 8.9 degrees . Postoperative thoracic kyphosis remained unchanged from 27.6 degrees to 19.9 degrees (p = 0.376); while lumbar lordosis improved significantly from +15.6 degrees to -22.4 degrees lordosis (p = 0.0002). Most patients had major to moderate improvement in postoperative functional and ambulatory status compared to the preoperative status. Thirteen (48.1%) perioperative complications were noted with five major complications (four respiratory in the form of hemothorax or respiratory failure that required ventilator support and one death) and eight minor complications (three UTI, two atelectasis, two neurological and one ileus). Postoperatively, we noted complications, such as coccygodynia with subluxation in 7, back sore on the convex side in 4 and dislodging of rod distally in 1 patient making a total of 12 (44.4%) postoperative complications. Of 12 postoperative complications, 6 (50%) required secondary procedure. We conclude that although flaccid neuromuscular scoliosis can be well corrected with posterior-only pedicle screw, there is a high rate of associated complications.

PMID: 19885687 [PubMed - as supplied by publisher]

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Effects of 2,4-diaminoquinazoline derivatives on SMN expression and phenotype in a mouse model for spinal muscular atrophy.

Hum Mol Genet. 2010 Feb 1;19(3):454-67

Authors: Butchbach ME, Singh J, Thorsteinsdóttir M, Saieva L, Slominski E, Thurmond J, Andrésson T, Zhang J, Edwards JD, Simard LR, Pellizzoni L, Jarecki J, Burghes AH, Gurney ME

Proximal spinal muscular atrophy (SMA), one of the most common genetic causes of infant death, results from the selective loss of motor neurons in the spinal cord. SMA is a consequence of low levels of survival motor neuron (SMN) protein. In humans, the SMN gene is duplicated; SMA results from the loss of SMN1 but SMN2 remains intact. SMA severity is related to the copy number of SMN2. Compounds which increase the expression of SMN2 could, therefore, be potential therapeutics for SMA. Ultrahigh-throughput screening recently identified substituted quinazolines as potent SMN2 inducers. A series of C5-quinazoline derivatives were tested for their ability to increase SMN expression in vivo. Oral administration of three compounds (D152344, D153249 and D156844) to neonatal mice resulted in a dose-dependent increase in Smn promoter activity in the central nervous system. We then examined the effect of these compounds on the progression of disease in SMN lacking exon 7 (SMNDelta7) SMA mice. Oral administration of D156844 significantly increased the mean lifespan of SMNDelta7 SMA mice by approximately 21-30% when given prior to motor neuron loss. In summary, the C5-quinazoline derivative D156844 increases SMN expression in neonatal mouse neural tissues, delays motor neuron loss at PND11 and ameliorates the motor phenotype of SMNDelta7 SMA mice.

PMID: 19897588 [PubMed - in process]

Spinal muscular atrophy: molecular mechanisms.

Curr Mol Med. 2009 Sep;9(7):851-62

Authors: Farrar MA, Johnston HM, Grattan-Smith P, Turner A, Kiernan MC

Spinal muscular atrophy (SMA) is a relatively common autosomal recessive neuromuscular disorder characterised by muscle weakness and atrophy due to degeneration of motor neurons of the spinal cord and cranial motor nuclei. The clinical phenotype incorporates a wide spectrum. No effective treatment is currently available and patients may experience severe physical disability which is often life limiting. The most common type of SMA is caused by homozygous disruption of the survival motor neuron 1 (SMN1) gene by deletion, conversion or mutation and results in insufficient levels of survival motor neuron (SMN) protein in motor neurons. While diagnosis is usually achieved by genetic testing, an illustrative clinical case is described that highlights the molecular and diagnostic complexities. While there is an emerging picture concerning the function of the SMN protein and the molecular pathophysiological mechanisms underpinning the disease, a number of substantial issues remain unresolved. The selective vulnerability of the motor neuron and the site and timing of the primary pathogenesis are not yet determined. Utilising the organisation of the SMN genomic region, recent advances have identified a number of potential therapeutic targets. As such, this review incorporates discussion of the clinical manifestations, molecular genetics, diagnosis, mechanisms of disease pathogenesis and development of novel treatment strategies.

PMID: 19860664 [PubMed - indexed for MEDLINE]

A negatively acting bifunctional RNA increases survival motor neuron both in vitro and in vivo.

Hum Gene Ther. 2008 Nov;19(11):1307-15

Authors: Dickson A, Osman E, Lorson CL

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder and is the leading genetic cause of infant mortality. SMA is caused by the loss of survival motor neuron-1 (SMN1). In humans, a nearly identical copy gene is present called SMN2, but this gene cannot compensate for the loss of SMN1 because of a single silent nucleotide difference in SMN2 exon 7. This single-nucleotide difference attenuates an exonic splice enhancer, resulting in the production of an alternatively spliced isoform lacking exon 7, which is essential for protein function. SMN2, however, is a critical disease modifier and is an outstanding target for therapeutic intervention because all SMA patients retain SMN2 and SMN2 maintains the same coding sequence as SMN1. Therefore, compounds or molecules that increase SMN2 exon 7 inclusion hold great promise for SMA therapeutics. Bifunctional RNAs have been previously used to increase SMN protein levels and derive their name from the presence of two domains: an antisense RNA sequence specific to the target RNA and an untethered RNA segment that serves as a binding platform for splicing factors. This study was designed to develop negatively acting bifunctional RNAs that recruit hnRNPA1 to exon 8 and block the general splicing machinery from the exon 8. By blocking the downstream splice site, this could competitively favor the inclusion of SMN exon 7 and therefore increase full-length SMN production. Here we identify a bifunctional RNA that stimulated full-length SMN expression in a variety of cell-based assays including SMA patient fibroblasts. Importantly, this molecule was also able to induce SMN expression in a previously described mouse model of SMA and demonstrates a novel therapeutic approach for SMA as well as a variety of diseases caused by a defect in splicing.

PMID: 19848583 [PubMed - indexed for MEDLINE]

Related Articles

Inflammation in ALS and SMA: Sorting out the good from the evil.

Neurobiol Dis. 2009 Oct 13;

Authors: Papadimitriou D, Le Verche V, Jacquier A, Ikiz B, Przedborski S, Re DB

Indices of neuroinflammation are found in a variety of diseases of the CNS including amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Over the years, neuroinflammation, in degenerative disorders of the CNS, has evolved from being regarded as an innocent bystander accomplishing its housekeeping function secondary to neurodegeneration to being considered as a bona fide contributor to the disease process and, in some situations, as a putative initiator of the disease. Herein, we will review neuroinflammation in both ALS and SMA not only from the angle of neuropathology but also from the angle of its potential role in the pathogenesis and treatment of these two dreadful paralytic disorders.

PMID: 19833209 [PubMed - as supplied by publisher]

Related Articles

The importance of the SMN genes in the genetics of sporadic ALS.

Amyotroph Lateral Scler. 2009 Oct-Dec;10(5-6):436-40

Authors: Corcia P, Camu W, Praline J, Gordon PH, Vourch P, Andres C

The human genome contains two SMN (survival motor neuron) genes: SMN1, the telomeric gene whose homozygous deletion causes spinal muscular atrophy (SMA), and SMN2, the centromeric version whose copy number modulates the phenotype of SMA. We performed a Medline search and reviewed all of the publications that focus on SMN1 and SMN2 in amyotrophic lateral sclerosis (ALS) to analyse whether these genes also act as risk factors or phenotypic modulators in ALS. While homozygous deletion of SMN1 was not associated in ALS, abnormal SMN1 copy numbers significantly increased the risk of ALS. The role of the SMN2 gene in ALS needs further clarification. The existence of abnormal SMN1 copy numbers in ALS provides additional evidence that gene copy number variants may contribute to neurodegeneration and might open new approaches to treatment.

PMID: 19922137 [PubMed - in process]

[Molecular-targeted therapies for spinal and bulbar muscular atrophy]

Rinsho Shinkeigaku. 2009 Nov;49(11):917-20

Authors: Katsuno M, Banno H, Suzuki K, Adachi H, Tanaka F, Sobue G

Spinal and bulbar muscular atrophy (SBMA) is a polyglutamine-mediated lower motor neuron disease characterized by slowly progressive muscle weakness and atrophy. The cause of this disease is the expansion of a trinucleotide CAG repeat, which encodes the polyglutamine tract, within the first exon of the androgen receptor (AR) gene. SBMA exclusively occurs in adult males, whereas both heterozygous and homozygous females are usually asymptomatic. Testosterone-dependent nuclear accumulation of the pathogenic AR protein has been considered to be a fundamental step of neurodegenerative process, which is followed by several molecular events such as transcriptional dysregulation, axonal transport disruption, and mitochondria dysfunction. Androgen deprivation suppresses the toxicity of the mutant AR in animal models of SBMA, and these insights have been translated to clinic. Animal studies have also suggested that activation of protein quality control systems are potential therapies for SBMA. To optimize "proof of concept", the process for testing candidate therapies in humans, it is of importance to identify responders to each therapy, to initiate interventions in early stages of the disease, and to establish biomarkers which can be used for evaluating the efficacy of treatment.

PMID: 20030248 [PubMed - in process]

Related Articles

Scapuloperoneal spinal muscular atrophy and CMT2C are allelic disorders caused by alterations in TRPV4.

Nat Genet. 2010 Feb;42(2):165-9

Authors: Deng HX, Klein CJ, Yan J, Shi Y, Wu Y, Fecto F, Yau HJ, Yang Y, Zhai H, Siddique N, Hedley-Whyte ET, Delong R, Martina M, Dyck PJ, Siddique T

Scapuloperoneal spinal muscular atrophy (SPSMA) and hereditary motor and sensory neuropathy type IIC (HMSN IIC, also known as HMSN2C or Charcot-Marie-Tooth disease type 2C (CMT2C)) are phenotypically heterogeneous disorders involving topographically distinct nerves and muscles. We originally described a large New England family of French-Canadian origin with SPSMA and an American family of English and Scottish descent with CMT2C. We mapped SPSMA and CMT2C risk loci to 12q24.1-q24.31 with an overlapping region between the two diseases. Further analysis reduced the CMT2C risk locus to a 4-Mb region. Here we report that SPSMA and CMT2C are allelic disorders caused by mutations in the gene encoding the transient receptor potential cation channel, subfamily V, member 4 (TRPV4). Functional analysis revealed that increased calcium channel activity is a distinct property of both SPSMA- and CMT2C-causing mutant proteins. Our findings link mutations in TRPV4 to altered calcium homeostasis and peripheral neuropathies, implying a pathogenic mechanism and possible options for therapy for these disorders.

PMID: 20037587 [PubMed - in process]

Bilateral neurogenic hip arthropathy. A case report.

Neuro Endocrinol Lett. 2009 Dec 30;30(6)

Authors: Kopec K, Kusz D, Cielinski L, Wojciechowski P, Hajduk G

Neurogenic arthropathy is a rare joint disorder, chracterized by rapid progression and marked destruction of articular surfaces (known as Charcot joint) with only mild to moderate pain. Most cases are related to diabetic neuropathy, but they may complicate the course of other neurogenic clinical conditions such as neurosyphilis (tabes dorsalis), syringomyelia, myelomeningocele, Peroneal Muscular Atrophy, spine or peripheral nerve injury, alcoholism and avitaminosis. Loss of superficial sensation and proprioception plays a pivotal role in development of arthropathy because it affects the joint's normal protective reflexes and leads to joint instability, degeneration and destruction. The authors describe an unusual case of bilateral neurogenic hip arthropathy in a 61-year old women who developed this condition in the course of multilevel lumbar spondylosis with spinal and nerve root compression. The patient underwent a successful bilateral hip replacement and remains almost asymptomatic contrary to literature reports that suggest high risk of complications after the operative treatment of Charcot joints.

PMID: 20038935 [PubMed - as supplied by publisher]

SAHA ameliorates the SMA phenotype in two mouse models for spinal muscular atrophy.

Hum Mol Genet. 2010 Jan 22;

Authors: Riessland M, Ackermann B, Förster A, Jakubik M, Hauke J, Garbes L, Fritzsche I, Mende Y, Blümcke I, Hahnen E, Wirth B

Proximal spinal muscular atrophy (SMA) is a common autosomal recessively inherited neuromuscular disorder determined by functional impairment of alpha-motor neurons within the spinal cord. SMA is caused by functional loss of the survival motor neuron gene 1 (SMN1), whereas disease severity is mainly influenced by the number of SMN2 copies. SMN2, which produces only low levels of full-length mRNA/protein, can be modulated by small molecules and drugs, thus offering a unique possibility for SMA therapy. Here, we analysed suberoylanilide hydroxamic acid (SAHA), a FDA-approved histone deacetylase inhibitor, as potential drug in two severe SMA mouse models each carrying two SMN2 transgenes: US-SMA mice with one SMN2 per allele (Smn(-/-);SMN2(tg/tg)) and Taiwanese-SMA mice with two SMN2 per allele (Smn(-/-);SMN2(tg/wt)), both on pure FVB/N background. The US-SMA mice were embryonically lethal with heterozygous males showing significantly reduced fertility. SAHA-treatment of pregnant mothers rescued the embryonic lethality giving rise to SMA offspring. By using a novel breeding strategy for the Taiwanese model (Smn(-/-);SMN2(tg/tg) x Smn(-/+) mice) we obtained 50% SMA offspring that survive approximately 10 days and 50% control carriers in each litter. Treatment with 25 mg/kg/2x/day SAHA increased lifespan of SMA mice by 30%, significantly improved motor function abilities, reduced degeneration of motor neurons within the spinal cord and increased the size of neuromuscular junctions and muscle fibers compared to vehicle-treated SMA mice. SMN RNA and protein levels were significantly elevated in various tissues including spinal cord and muscle. Hence, SAHA, which lessens the progression of SMA, might be suitable for SMA therapy.

PMID: 20097677 [PubMed - as supplied by publisher]

Related Articles

Neuromuscular defects and breathing disorders in a new mouse model of spinal muscular atrophy.

Neurobiol Dis. 2010 Jan 18;

Authors: Michaud M, Arnoux T, Bielli S, Durand E, Rotrou Y, Jablonka S, Robert F, Giraudon-Paoli M, Riessland M, Mattei MG, Andriambeloson E, Wirth B, Sendtner M, Gallego J, Pruss RM, Bordet T

Spinal muscular atrophy (SMA) is caused by insufficient levels of the survival motor neuron (SMN) protein leading to muscle paralysis and respiratory failure. In mouse, introducing the human SMN2 gene partially rescues Smn(-)(/)(-) embryonic lethality. However current models were either too severe or nearly unaffected precluding convenient drug testing for SMA. We report here new SMN2;Smn(-/-) lines carrying one to four copies of the human SMN2 gene. Mice carrying three SMN2 copies exhibited an intermediate phenotype with delayed appearance of motor defects and developmental breathing disorders reminiscent of those found in severe SMA patients. Although normal at birth, at 7 days of age respiratory rate was decreased and apnea frequency was increased in SMA mice in parallel with the appearance of neuromuscular junction defects in the diaphragm. With median survival of 15 days and postnatal onset of neurodegeneration, these mice could be an important tool for evaluating new therapeutics.

PMID: 20085811 [PubMed - as supplied by publisher]

[Molecular-targeted therapy for neurodegenerative diseases]

Rinsho Shinkeigaku. 2009 Nov;49(11):747-9

Authors: Sobue G

Neurodegenerative diseases have been construed as incurable disorders. However, therapeutic development for these diseases is now facing a turning point: analyses of cellular and animal models have provided insights into pathogenesis of neurodegenerative diseases, and have indicated rational therapeutic approaches to them. Therefore, how to realize molecular targeted therapy for neurodegenerative diseases is becoming one of the most challenging issues in the clinical neurology. Primarily, pathophysiological understanding of the disease from basic science is the first step. For the successful clinical trials, effective trial design, sufficient economic and social support, and education are indispensable. The development of androgen deprivation therapy for spinal and bulbar muscular atrophy (SBMA) is a representative study in this field. SBMA is a hereditary neurodegenerative disease caused by expansion of a trinucleotide CAG repeat in the first exon of the androgen receptor (AR) gene. There is increasing evidence that testosterone, the ligand of AR, plays a pivotal role in the neurodegeneration in SBMA. The striking success of androgen deprivation therapy in SBMA mouse models has been translated into phase 2, and then phase 3, clinical trials.

PMID: 20030200 [PubMed - in process]

Identification of multipotent cytotrophoblast cells from human first trimester chorionic villi.

Cloning Stem Cells. 2009 Dec;11(4):535-56

Authors: Spitalieri P, Cortese G, Pietropolli A, Filareto A, Dolci S, Klinger FG, Giardina E, Di Cesare S, Bernardini L, Lauro D, Scaldaferri HL, Citro G, Novelli G, De Felici M, Sangiuolo F

In this article we used immunohistochemistry and FACS analyses to show that cells expressing markers typical of human stem cells such as SSEA4, OCT-4, ALP, and CD117 are present within the cytotrophoblastic tissue of human fetal chorionic villus samples (CVSs). After immunoselection of CV cells for SSEA4, FACS analyses showed an increased number of cells positive for OCT-4 and ALP and a small percentage (around 4%) of side population (SP) cells. In the same cell population, RT-PCR indicated the presence of OCT-4, NANOG, and SOX2 transcripts, also typical of stem cells. Depending on the in vitro conditions, a subset of SSEA4+ cells formed colonies resembling hESCs, with limited self renewal ability. At the same time, these cells were able to differentiate in vitro into derivatives of all three germ layers. When inoculated into immunocompromised mice, SSEA4+ cells did not form teratomas but were able to populate depleted hematopoietic tissues. Moreover, after injection into mouse blastocysts, they were incorporated into the inner cell mass and could be traced into several tissues of the adult chimeric mice. Finally, we show that SSEA4+ cells isolated from fetuses affected by Spinal Muscular Atrophy (SMA) can be genetically corrected with high efficiency in culture by Small Fragment Homologous Recombination (SFHR), a gene targeting approach. Taken together, our results indicate that SSEA4+ cells obtained from human CVSs contain a subpopulation of multipotent cells that we propose to name Human Cytotrophoblastic-derived Multipotent Cells (hCTMCs). These cells may be a safe and convenient source of cells for cell-based therapy, as well as an ideal target for in utero fetal gene therapy.

PMID: 20025524 [PubMed - in process]

Motor neuron disease: systematic reviews of treatment for ALS and SMA.

Br Med Bull. 2009 Dec 15;

Authors: Orrell RW

Introduction There is no curative treatment for the common motor neuron diseases, amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy. Nevertheless, there is an increasing volume of published studies. This review assesses the current evidence for treatment of these conditions. Sources of data Primarily, the systematic reviews of the Cochrane Collaboration, with additional reference to other systematic reviews and online sites. Areas of agreement Riluzole remains the only medication with demonstrated efficacy and regulatory approval for the treatment of ALS. Areas of controversy, growing points and areas timely for developing research The design of clinical trials and the publication of unsatisfactory studies, in both human and animal models, continue to cause confusion in advising on patient management. Improvements in trial design, critical assessment of studies for publication and avoidance of bias towards publication of positive results are needed. A better understanding of pathogenesis should lead to more potent interventions.

PMID: 20015852 [PubMed - as supplied by publisher]

Related Articles

Conservative care of temporomandibular joint disorder in a 35-year-old patient with spinal muscular atrophy type III: a case study.

J Chiropr Med. 2009 Dec;8(4):187-92

Authors: Houle S, Descarreaux M

OBJECTIVE: This article describes the chiropractic clinical management and therapeutic benefits accruing to a patient with temporomandibular joint (TMJ) disorder and spinal muscular atrophy type III. CLINICAL FEATURES: A 35-year-old white man presented at the university chiropractic outpatient clinic with a complaint of masseter muscle pain and mouth-opening restriction. Temporomandibular joint range of motion evaluation revealed restricted opening (11 mm interincisival), and pain was rated by the patient at an intensity of 5 on a pain scale of 0 to 10. INTERVENTION AND OUTCOME: Chiropractic care was provided and included TMJ mobilization, myofascial therapy, trigger point therapy, and light spinal mobilizations of the upper cervical vertebrae. Final evaluation of TMJ range of motion showed active opening of 12 mm with absence of pain and muscle tenderness of the jaw. CONCLUSION: This case suggests that a patient with musculoskeletal disorders related to underlying neurodegenerative pathologies may benefit from chiropractic management adapted to their condition. In the present case, chiropractic treatment of the TMJ represented a viable, low-cost approach with limited adverse effects compared with surgery.

PMID: 19948309 [PubMed - in process]

Related Articles

Subcutaneous administration of TC007 reduces disease severity in an animal model of SMA.

BMC Neurosci. 2009;10:142

Authors: Mattis VB, Fosso MY, Chang CW, Lorson CL

BACKGROUND: Spinal Muscular Atrophy (SMA) is the leading genetic cause of infantile death. It is caused by the loss of functional Survival Motor Neuron 1 (SMN1). There is a nearly identical copy gene, SMN2, but it is unable to rescue from disease due to an alternative splicing event that excises a necessary exon (exon 7) from the majority of SMN2-derived transcripts. While SMNDelta7 protein has severely reduced functionality, the exon 7 sequences may not be specifically required for all activities. Therefore, aminoglycoside antibiotics previously shown to suppress stop codon recognition and promote translation read-through have been examined to increase the length of the SMNDelta7 C-terminus. RESULTS: Here we demonstrate that subcutaneous-administration of a read-through inducing compound (TC007) to an intermediate SMA model (Smn-/-; SMN2+/+; SMNDelta7) had beneficial effects on muscle fiber size and gross motor function. CONCLUSION: Delivery of the read-through inducing compound TC007 reduces the disease-associated phenotype in SMA mice, however, does not significantly extend survival.

PMID: 19948047 [PubMed - indexed for MEDLINE]

Related Articles

Aging and sequelae of poliomyelitis.

Ann Phys Rehabil Med. 2009 Nov 10;

Authors: Laffont I, Julia M, Tiffreau V, Yelnik A, Herisson C, Pelissier J

OBJECTIVE: We estimate that there are about 50,000 persons who survived poliomyelitis in their childhood in France (mean age estimated between 50 and 65 years). After a few decades of stability, 30 to 65% of individuals who had been infected and recovered from polio begin to experience new signs and symptoms. METHOD: Review of the literature on Pubmed with the following keywords "Poliomyelitis" and "Post-Polio Syndrome (PPS)". RESULTS: These new signs and symptoms are characterized by muscular atrophy (decreased muscle mass), muscle weakness and fatigue, muscle and/or joint pain. All these symptoms lead to significant changes in mobility with falls and inability to carry on with daily life activities. There are several intricate causes. The normal aging process and weight gain are regularly blamed. Respiratory disorders and sleep disorders must be looked for: respiratory insufficiency, sleep-related breathing disorders such as sleep apnea, restless legs syndrome. Orthopedics complications are quite common: soft-tissue pathologies of the upper limbs, degenerative pathologies of the large joints or spinal cord, fall-related fractures. Finally, the onset of an authentic PPS is possible. CONCLUSION: The therapeutic care of this late functional deterioration requires regular monitoring check-ups in order to implement preventive measures and appropriate treatment. This therapeutic care must be multidisciplinary as physical rehabilitation; orthotics and technical aids are all essential.

PMID: 19944665 [PubMed - as supplied by publisher]

Society for Neuroscience - 39th Annual Meeting. Part 2 - Novel therapies for neurodegenerative disorders and other CNS diseases.

IDrugs. 2009 Dec;12(12):734-7

Authors: Al-Shamahi A, Kirkham K, Hookes L

The 39th Annual Meeting of the Society for Neuroscience (SFN), held in Chicago, included topics covering new therapeutic developments in the field of neuroscience. This conference report highlights selected presentations on novel neuroprotective and antiparkinsonian agents, and compounds in development for the treatment of dementia, schizophrenia, depression, obesity and spinal muscular atrophy. Investigational drugs discussed include velusetrag and TD-8954 (both from Theravance Inc), SEP-228791 and SEP-226330 (both from Sepracor Inc), ADL-5510 (Adolor Corp), PF-217830 (Pfizer Inc), KB-099520 (Karo Bio AB), tesofensine (NeuroSearch A/S) and TRP6-01 (Theraptosis).

PMID: 19943211 [PubMed - indexed for MEDLINE]

Channelopathies converge on TRPV4.

Nat Genet. 2010 Feb;42(2):98-100

Authors: Nilius B, Owsianik G

Scapuloperoneal spinal muscular atrophy and Charcot-Marie-Tooth disease type 2C are inherited neurodegenerative diseases characterized by sensory defects and muscle weakness. Three new studies demonstrate that they are allelic disorders caused by mutations in the vanilloid transient receptor potential cation-channel gene TRPV4.

PMID: 20104247 [PubMed - in process]

Clinical Neurobiology, Institute of Biomedical and Clinical Science, Peninsula Medical School, St Luke's Campus, Exeter, EX1 2LU, United Kingdom.

Childhood spinal muscular atrophy (SMA) is an autosomal recessive disorder characterised by loss of the alpha motor neurones of the spinal cord. SMA is cause by mutations in the survival motor neuron (SMN) gene. There are two copies of the SMN gene: SMN1 and SMN2. The two genes differ by only 11 nucleotides at the genomic level. One of these is a C to T single nucleotide polymorphism (SNP) at position 6 in exon 7. This change alters an exon splicing enhancer in exon 7, meaning that while SMN1 expresses exclusively full-length protein containing exon 7, SMN2 is predominantly alternatively spliced and expresses a truncated transcript lacking exon 7 (SMN7). As all SMA patients are effectively null for SMN1 but retain at least one copy of SMN2, patients express considerably lower levels of functional SMN protein compared with uneffected individuals. Therefore, SMA is triggered by a fall in the levels of expressed full-length protein, and the levels expressed by the retained SMN2 gene control the severity. As a result, RNA manipulation to suppress the alternative splicing event and thus increase SMN exon 7 inclusion has emerged as an attractive therapeutic approach. In this review we have discussed the current state of bifunctional RNAs as a viable therapy, concentrating on recent advances and overall implications of this research on SMA.

Spinal muscular atrophy is an entity of neurodegenerative disorders at the anterior horn neuron of the spinal cord caused by telomeric survival motor neuron gene abnormality. There is no definitive treatment for spinal muscular atrophy, but recent reports have indicated the efficacy of intravenous injection, but not oral administration, of thyrotropin-releasing hormone (TRH). We treated an 18-year-old male patient with spinal muscular atrophy type III by oral administration of the thyrotropin-releasing hormone analogue, taltireline hydrate. His muscle strength increased significantly after the therapy, and he showed no clinical or laboratory identifiable adverse effects, including thyroid-stimulating hormone suppression that had been observed with intravenous thyrotropin-releasing hormone therapy...

Department of Genetic Epidemiology, Kobe University Graduate School of Medicine, Kobe, Japan.

Spinal muscular atrophy (SMA) is caused by loss of SMN1. A nearly identical gene, SMN2, fails to compensate for the loss of SMN1 because SMN2 produces mainly an exon 7-skipped product. The +6C in SMN1 exon 7 proceeds to include exon 7 into mRNA, while the +6U in SMN2 causes skipping of exon 7. Here, approximately 45kD proteins bound to the SMN exon 7 RNA probe was found, and identified as hnRNP C1/C2. In gel-shift assay, hnRNP C1/C2 had a greater affinity for the RNA probe with +6C than for the RNA probe with +6U. In vitro splicing assay showed that anti-hnRNP C1/C2 antibody hampered splicing of SMN1 exon 7, but did not affect splicing of SMN2 exon 7. In conclusion, we showed the possibility that hnRNP C1/C2 enhanced SMN1 exon 7 splicing specifically.

ABSTRACT: BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive hereditary disorder caused by mutations of the survival motor neuron 1 (SMN1) gene. Recently, high-resolution DNA melting analysis (HRMA) with saturation LC Green dyes has become a powerful post-PCR technique for genotyping or mutation scanning. So far, no studies have applied HRMA to the molecular analysis of SMA. METHODS: The exon 7 and the flanking area of the SMN1 and SMN2 genes of 55 SMA patients and 46 unrelated normal individuals were amplified with asymmetric PCR with unlabeled probe and symmetric PCR without probe, respectively. The saturation LC Green dyes were added to the PCR system. The PCR products were loaded onto the LightScanner system and were melted from 60 to 95 centi-degree slowly. The melting curves were acquired and analyzed by the LightScanner software. RESULTS: Three types of melting curves that correlated with the presumed genotype of SMA patients and controls were clearly separated on the HRMA chromatogram with the unlabeled probe. The 55 SMA patients and 46 non-SMA controls were identified with HRMA with a 100% clinical sensitivity. CONCLUSIONS: The HRMA with saturation LC Green dyes and unlabeled probe appears to be a suitable, alternative method for the diagnosis of SMA, with high sensitivity and specificity.

Splicing therapeutics are defined as the deliberate modification of RNA splicing to achieve therapeutic goals. Various techniques for splicing therapeutics have been described, and most of these involve the use of antisense oligonucleotide-based compounds that target key elements in the pre-mRNA to control splicing in the nucleus. In this review, recent developments in splicing therapeutics for the treatment of two specific diseases are described: correcting the alternative splicing of survival of motor neuron (SMN)2 pre-mRNA to compensate for the defective SMN1 gene in spinal muscular atrophy, and re-engineering the splicing of apolipoprotein B pre-mRNA to lower circulating cholesterol levels.

Spinal muscular atrophy (SMA) is caused by degeneration of anterior horn cells, which leads to progressive muscle weakness. Children with SMA type II do not develop the ability to walk without support and have a shortened life expectancy, whereas children with SMA type III develop the ability to walk and have a normal life expectancy. There are no known efficacious drug treatments that influence the disease course of SMA...

Department of Molecular Microbiology and Immunology.

Spinal muscular atrophy (SMA) is a motor neuron disease caused by the loss of survival motor neuron-1 (SMN1). A nearly identical copy gene, SMN2, is present in all SMA patients, which produces low levels of functional protein...

Centre de Regulació Genòmica, 08003 Barcelona, Spain.

Spinal Muscular atrophy is a prevalent genetic disease caused by mutation of the SMN1 gene, which encodes the SMN protein involved in assembly of small nuclear ribonucleoprotein (snRNP) complexes. A paralog of the gene, SMN2, cannot provide adequate levels of functional SMN because exon 7 is skipped in a significant fraction of the mature transcripts...

Charlotte J. Sumner, MD 600 North Wolfe Street, Meyer 5-119b, Baltimore, MD 21287, USA. csumner1@jhmi.edu.

The motor neuron disease spinal muscular atrophy (SMA) is one of the leading genetic killers of infants worldwide...

Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of lower motor neurons and occasionally bulbar motor neurons leading to progressive limb and trunk paralysis as well as muscular atrophy...