Search

Despite investment of billions of research dollars, neurodegenerative diseases have been largely resistant to therapeutics development because of incomplete understanding of molecular basis of disease, paucity of disease proximal targets, [...]

ObjectiveIn utero SMA treatment could improve survival and neurologic outcomes. We investigated the attitudes of patients and parents with SMA regarding prenatal diagnosis, fetal therapies, and clinical trials.MethodsA multidisciplinary team designed a questionnaire that Cure SMA electronically distributed to parents and patients (>18 years old) affected by SMA. Multivariable ordinal logistic regression was used to analyze associations between respondent characteristics and attitudes.ResultsOf 114 respondents (60% of whom were patients), only 2 were prenatally diagnosed. However, 91% supported prenatal testing and 81% felt there had been a delay in their diagnosis. Overall, 55% would enroll in a phase I trial for fetal antisense oligonucleotide (ASO) while 79% would choose an established fetal ASO/small molecule therapy. Overall, 61% would enroll in fetal gene therapy trials and 87% would choose fetal gene therapies. Patients were less likely to enroll in a fetal gene therapy trial than parents enrolling a child (OR 0.31, p

Twin girls born at 30 weeks' gestation with spinal muscular atrophy (SMA) received onsasemnogene‐abeparvovec (OA) at 3.5 weeks of life. They had no treatment‐related adverse events, normal acquisition of motor milestones, and normal neurological examination at 19 months. Genotyping revealed 0 copies of SMN1 and a single, hybrid SMN2 gene containing the positive genetic modifier c.835‐44A>G. This was associated with full‐length SMN2 blood mRNA expression levels similar to a 2 copy SMA infant. The observed favorable outcomes are likely due to the genetic modifier combined with early drug administration enabled by prematurity. [ABSTRACT FROM AUTHOR]

Notch signaling is a highly conserved intercellular pathway with tightly regulated and pleiotropic roles in normal tissue development and homeostasis. Dysregulated Notch signaling has also been implicated in human disease, including multiple forms of cancer, and represents an emerging therapeutic target. Successful development of such therapeutics requires a detailed understanding of potential on-target toxicities. Here, we identify autosomal dominant mutations of the canonical Notch ligand Jagged1 (or JAG1) as a cause of peripheral nerve disease in 2 unrelated families with the hereditary axonal neuropathy Charcot-Marie-Tooth disease type 2 (CMT2). Affected individuals in both families exhibited severe vocal fold paresis, a rare feature of peripheral nerve disease that can be life- threatening. Our studies of mutant protein posttranslational modification and localization indicated that the mutations (p.Ser577Arg, p.Ser650Pro) impair protein glycosylation and reduce JAG1 cell surface expression. Mice harboring heterozygous CMT2-associated mutations exhibited mild peripheral neuropathy, and homozygous expression resulted in embryonic lethality by midgestation. Together, our findings highlight a critical role for JAG1 in maintaining peripheral nerve integrity, particularly in the recurrent laryngeal nerve, and provide a basis for the evaluation of peripheral neuropathy as part of the clinical development of Notch pathway-modulating therapeutics., Introduction The Notch pathway is a highly conserved cell-cell signaling mechanism that functions in virtually all tissues to regulate multiple aspects of cell fate and homeostasis. Dysregulation of Notch signaling [...]

BACKGROUND. Spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein. New SMN-enhancing therapeutics are associated with variable clinical benefits. Limited knowledge of baseline and drug-induced SMN levels in disease-relevant tissues hinders efforts to optimize these treatments. METHODS. SMN mRNA and protein levels were quantified in human tissues isolated during expedited autopsies. RESULTS. SMN protein expression varied broadly among prenatal control spinal cord samples, but was restricted at relatively low levels in controls and SMA patients after 3 months of life. A 2.3-fold perinatal decrease in median SMN protein levels was not paralleled by comparable changes in SMN mRNA. In tissues isolated from nusinersen-treated SMA patients, antisense oligonucleotide (ASO) concentration and full-length (exon 7 including) SMN2 (SMN2-FL) mRNA level increases were highest in lumbar and thoracic spinal cord. An increased number of cells showed SMN immunolabeling in spinal cord of treated patients, but was not associated with an increase in whole-tissue SMN protein levels. CONCLUSIONS. A normally occurring perinatal decrease in whole-tissue SMN protein levels supports efforts to initiate SMN-inducing therapies as soon after birth as possible. Limited ASO distribution to rostral spinal and brain regions in some patients likely limits clinical response of motor units in these regions for those patients. These results have important implications for optimizing treatment of SMA patients and warrant further investigations to enhance bioavailability of intrathecally administered ASOs. FUNDING. SMA Foundation, SMART, NIH (R01-NS096770, R01-NS062869), Ionis Pharmaceuticals, and PTC Therapeutics. Biogen provided support for absolute real-time RT-PCR., Introduction The neuromuscular disease spinal muscular atrophy (SMA), affecting approximately 1 in 10,000 individuals, is the most common inherited cause of infant death (1). The most frequent and severe type [...]

#MeToo in academia The #MeToo movement has taken on sexual harassment in the workplace and served to inform the world that these unacceptable and illegal acts have become commonplace, including [...]

The motor neuron disease spinal muscular atrophy (SMA) is caused by recessive, loss-of-function mutations of the survival motor neuron 1 gene (SMN1). Alone, such mutations are embryonically lethal, but SMA patients retain a paralog gene, SMN2, that undergoes alternative pre-mRNA splicing, producing low levels of SMN protein. By mechanisms that are not well understood, reduced expression of the ubiquitously expressed SMN protein causes an early-onset motor neuron disease that often results in infantile or childhood mortality. Recently, striking clinical improvements have resulted from two novel treatment strategies to increase SMN protein by (a) modulating the splicing of existing SMN2 pre-mRNAs using antisense oligonucleotides, and (b) transducing motor neurons with self-complementary adeno-associated virus 9 (scAAV9) expressing exogenous SMN1 cDNA. We review the recently published clinical trial results and discuss the differing administration, tissue targeting, and potential toxicities of these two therapies. We also focus on the challenges that remain, emphasizing the many clinical and biologic questions that remain open. Answers to these questions will enable further optimization of these remarkable SMA treatments as well as provide insights that may well be useful in application of these therapeutic platforms to other diseases., In the century following its original description in 1891 (1), the degenerative neuromuscular disorder spinal muscular atrophy (SMA) was considered one of the most hopeless of maladies. A shift in [...]

A recent demonstration by Van Alstyne and colleagues (1) of long-term toxicity following short-term successful treatment of an animal model of spinal muscular atrophy (SMA) by gene transfer-mediated overexpression of [...]

The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by mutation of the telomeric survival motor neuron 1 (SMN1) gene with retention of the centromeric SMN2 gene. We [...]

The microtubule motor cytoplasmic dynein and its activator dynactin drive vesicular transport and mitotic spindle organization. Dynactin is ubiquitously expressed in eukaryotes, but a G59S mutation in the [p150.sup.Glued] subunit of dynactin results in the specific degeneration of motor neurons. This mutation in the conserved cytoskeleton-associated protein, glycine-rich (CAP-Gly) domain lowers the affinity of [p150.sup.Glued] for microtubules and EB1. Cell lines from patients are morphologically normal but show delayed recovery after nocodazole treatment, consistent with a subtle disruption of dynein/dynactin function. The G59S mutation disrupts the folding of the CAP-Gly domain, resulting in aggregation of the [p150.sup.Glued] protein both in vitro and in viva, which is accompanied by an increase in cell death in a motor neuron cell line. Overexpression of the chaperone Hsp70 inhibits aggregate formation and prevents cell death. These data support a model in which a point mutation in [p150.sup.Glued] causes both loss of dynein/dynactin function and gain of toxic function, which together lead to motor neuron cell death.

Abstract Background The motor neuron degenerative disease spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality and is caused by mutations in the survival of motor neurons (SMN) gene that reduce the expression levels of the SMN protein. A major goal of current therapeutic approaches is to increase SMN levels in SMA patients. The purpose of this study was to develop a reliable assay to measure SMN protein levels from peripheral blood samples. Methods We developed a novel cell immunoassay to quantitatively measure SMN levels from peripheral blood mononuclear cells (PBMCs) using a single anti-SMN antibody. Results SMN levels determined by the cell immunoassay are comparable to levels determined by Western blot, but in contrast, the immunoassay does not involve cell lysis, requires a small amount of patient material, and can be done on a large number of samples simultaneously. SMN levels from PBMCs are not influenced by cell type heterogeneity. Conclusion SMN levels measured from total PBMCs provide an important snapshot of SMN protein expression, which should be a useful aid in SMA diagnosis, and a surrogate marker of efficacy of treatment in SMA clinical trials.