scholarly journals Development of Multiexon Skipping Antisense Oligonucleotide Therapy for Duchenne Muscular Dystrophy

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yoshitsugu Aoki ◽  
Toshifumi Yokota ◽  
Matthew J. A. Wood
Keyword(s):  
Clinical Trials ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Genetic Disorder ◽  
Premature Death ◽  
Degenerative Disorder ◽  
Antisense Oligonucleotide Therapy ◽  
Treat All ◽  
Dystrophin Protein ◽  
Preclinical Work

Duchenne muscular dystrophy (DMD) is an incurable, X-linked progressive muscle degenerative disorder that results from the absence of dystrophin protein and leads to premature death in affected individuals due to respiratory and/or cardiac failure typically by age of 30. Very recently the exciting prospect of an effective oligonucleotide therapy has emerged which restores dystrophin protein expression to affected tissues in DMD patients with highly promising data from a series of clinical trials. This therapeutic approach is highly mutation specific and thus is personalised. Therefore DMD has emerged as a model genetic disorder for understanding and overcoming of the challenges of developing personalised genetic medicines. One of the greatest weaknesses of the current oligonucleotide approach is that it is a mutation-specific therapy. To address this limitation, we have recently demonstrated that exons 45–55 skipping therapy has the potential to treat clusters of mutations that cause DMD, which could significantly reduce the number of compounds that would need to be developed in order to successfully treat all DMD patients. Here we discuss and review the latest preclinical work in this area as well as a variety of accompanying issues, including efficacy and potential toxicity of antisense oligonucleotides, prior to human clinical trials.

scholarly journals Challenges of Interpreting Dystrophin Content by Western Blot

US Neurology ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 40 ◽  
Author(s):  
Frederick J Schnell ◽  
Diane Frank ◽  
Sue Fletcher ◽  
Russell D Johnsen ◽  
Steve D Wilton ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Data Analysis ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Western Blot ◽  
Becker Muscular Dystrophy ◽  
Human Muscle ◽  
Healthy Human ◽  
Dystrophin Protein ◽  
Western Blot Data

The Duchenne muscular dystrophy community has recently seen the first approved therapy for the restoration of dystrophin, based on its ability to increase levels of dystrophin protein, as determined by western blot. The approval, along with the initiation of clinical trials evaluating other dystrophin-restoring therapies, highlights the importance of accurate dystrophin quantitation. Nonoptimized western blot methods can reflect inaccurate results, especially in the quantitation of low dystrophin levels. A few key changes to standards and data analysis parameters can result in a low level of dystrophin (<0.5% of a healthy biopsy) being inaccurately interpreted as >20% of the levels reported in healthy human muscle. A review of the dystrophin western blot data on Duchenne and Becker muscular dystrophy biopsies is conducted, along with a thorough investigation of methodologies to quantify dystrophin.

scholarly journals Disruption of a key ligand-H-bond network drives dissociative properties in vamorolone for Duchenne muscular dystrophy treatment

2020 ◽  
Vol 117 (39) ◽  
pp. 24285-24293
Author(s):  
Xu Liu ◽  
Yashuo Wang ◽  
Jennifer S. Gutierrez ◽  
Jesse M. Damsker ◽  
Kanneboyina Nagaraju ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Side Effects ◽  
Muscular Dystrophy ◽  
Genetic Disorder ◽  
Premature Death ◽  
Standard Of Care ◽  
Therapeutic Index ◽  
Therapeutic Effects ◽  
Current Standard ◽  
Future Design

Duchenne muscular dystrophy is a genetic disorder that shows chronic and progressive damage to skeletal and cardiac muscle leading to premature death. Antiinflammatory corticosteroids targeting the glucocorticoid receptor (GR) are the current standard of care but drive adverse side effects such as deleterious bone loss. Through subtle modification to a steroidal backbone, a recently developed drug, vamorolone, appears to preserve beneficial efficacy but with significantly reduced side effects. We use combined structural, biophysical, and biochemical approaches to show that loss of a receptor-ligand hydrogen bond drives these remarkable therapeutic effects. Moreover, vamorolone uniformly weakens coactivator associations but not corepressor associations, implicating partial agonism as the main driver of its dissociative properties. Additionally, we identify a critical and evolutionarily conserved intramolecular network connecting the ligand to the coregulator binding surface. Interruption of this allosteric network by vamorolone selectively reduces GR-driven transactivation while leaving transrepression intact. Our results establish a mechanistic understanding of how vamorolone reduces side effects, guiding the future design of partial agonists as selective GR modulators with an improved therapeutic index.

scholarly journals Genotype characterization and delayed loss of ambulation by glucocorticoids in a large cohort of patients with Duchenne muscular dystrophy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shu Zhang ◽  
◽  
Dongdong Qin ◽  
Liwen Wu ◽  
Man Li ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Hazard Ratio ◽  
Large Cohort ◽  
Muscle Disease ◽  
Clinical Progression ◽  
Large Deletions ◽  
The Mean ◽  
Lower Hazard

Abstract Background Duchenne muscular dystrophy (DMD) is the most common genetic muscle disease in human. We aimed to describe the genotype distribution in a large cohort of Chinese DMD patients and their delayed loss of ambulation by glucocorticoid (GC) treatments. This is to facilitate protocol designs and outcome measures for the emerging DMD clinical trials. Results A total of 1163 patients with DMD were recruited and genotyped. Genotype variations were categorized as large deletions, large duplications, and small mutations. Large deletions were further analyzed for those amenable to exon-skipping therapies. Participants aged 5 years or older were grouped into GC-treated and GC-naïve groups. Clinical progression among different genotypes and their responses to GC treatments were measured by age at loss of ambulation (LOA). Among the mutation genotypes, large deletions, large duplications, and small mutations accounted for 68.79%, 7.14%, and 24.07%, respectively. The mean age at diagnosis was 4.59 years; the median ages at LOA for the GC-naïve, prednisone/prednisolone-treated, and deflazacort-treated groups were 10.23, 12.02, and 13.95 years, respectively. The “deletion amenable to skipping exon 44” subgroup and the nonsense-mutation subgroup had older ages at LOA than the “other deletions” subgroup. Subgroups were further analyzed by both genotypes and GC status. All genotypes showed significant beneficial responses to GC treatment. Deletions amenable to skipping exon 44 showed a lower hazard ratio (0.155). The mean age at death was 18.57 years in this DMD group. Conclusion Genotype variation influences clinical progression in certain DMD groups. Beneficial responses to GC treatment were observed among all DMD genotypes. Compared with other genotypes, deletions amenable to skipping exon 44 had a lower hazard ratio, which may indicate a stronger protective effect of GC treatments on this subgroup. These data are valuable for designing future clinical trials, as clinical outcomes may be influenced by the genotypes.

scholarly journals The administration of antisense oligonucleotide golodirsen reduces pathological regeneration in patients with Duchenne muscular dystrophy

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Dominic Scaglioni ◽  
Francesco Catapano ◽  
Matthew Ellis ◽  
Silvia Torelli ◽  
Darren Chambers ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Antisense Oligonucleotide ◽  
De Novo ◽  
Exon Skipping ◽  
Significant Negative Correlation ◽  
Entire Cohort ◽  
Associated Proteins ◽  
Analysis Platform ◽  
Dystrophin Protein

AbstractDuring the last decade, multiple clinical trials for Duchenne muscular dystrophy (DMD) have focused on the induction of dystrophin expression using different strategies. Many of these trials have reported a clear increase in dystrophin protein following treatment. However, the low levels of the induced dystrophin protein have raised questions on its functionality. In our present study, using an unbiased, high-throughput digital image analysis platform, we assessed markers of regeneration and levels of dystrophin associated protein via immunofluorescent analysis of whole muscle sections in 25 DMD boys who received 48-weeks treatment with exon 53 skipping morpholino antisense oligonucleotide (PMO) golodirsen. We demonstrate that the de novo dystrophin induced by exon skipping with PMO golodirsen is capable of conferring a histological benefit in treated patients with an increase in dystrophin associated proteins at the dystrophin positive regions of the sarcolemma in post-treatment biopsies. Although 48 weeks treatment with golodirsen did not result in a significant change in the levels of fetal/developmental myosins for the entire cohort, there was a significant negative correlation between the amount of dystrophin and levels of regeneration observed in different biopsy samples. Our results provide, for the first time, evidence of functionality of induced dystrophin following successful therapeutic intervention in the human.

scholarly journals Autophagy in the heart is enhanced and independent of disease progression in mus musculus dystrophinopathy models

2019 ◽  
Vol 8 ◽  
pp. 204800401987958
Author(s):  
HR Spaulding ◽  
C Ballmann ◽  
JC Quindry ◽  
MB Hudson ◽  
JT Selsby
Keyword(s):  
Skeletal Muscle ◽  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Disease Progression ◽  
Gene Mutations ◽  
Dystrophin Gene ◽  
Mdx Mice ◽  
Dystrophin Deficiency ◽  
Muscle Wasting Disease ◽  
Dystrophin Protein

Background Duchenne muscular dystrophy is a muscle wasting disease caused by dystrophin gene mutations resulting in dysfunctional dystrophin protein. Autophagy, a proteolytic process, is impaired in dystrophic skeletal muscle though little is known about the effect of dystrophin deficiency on autophagy in cardiac muscle. We hypothesized that with disease progression autophagy would become increasingly dysfunctional based upon indirect autophagic markers. Methods Markers of autophagy were measured by western blot in 7-week-old and 17-month-old control (C57) and dystrophic (mdx) hearts. Results Counter to our hypothesis, markers of autophagy were similar between groups. Given these surprising results, two independent experiments were conducted using 14-month-old mdx mice or 10-month-old mdx/Utrn± mice, a more severe model of Duchenne muscular dystrophy. Data from these animals suggest increased autophagosome degradation. Conclusion Together these data suggest that autophagy is not impaired in the dystrophic myocardium as it is in dystrophic skeletal muscle and that disease progression and related injury is independent of autophagic dysfunction.

scholarly journals The Interplay of Mitophagy and Inflammation in Duchenne Muscular Dystrophy

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 648
Author(s):  
Andrea L. Reid ◽  
Matthew S. Alexander
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mitochondrial Dysfunction ◽  
Disease Onset ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Muscle Disease ◽  
Mitochondrial Morphology ◽  
Gene Therapies ◽  
Dystrophin Protein

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease caused by a pathogenic disruption of the DYSTROPHIN gene that results in non-functional dystrophin protein. DMD patients experience loss of ambulation, cardiac arrhythmia, metabolic syndrome, and respiratory failure. At the molecular level, the lack of dystrophin in the muscle results in myofiber death, fibrotic infiltration, and mitochondrial dysfunction. There is no cure for DMD, although dystrophin-replacement gene therapies and exon-skipping approaches are being pursued in clinical trials. Mitochondrial dysfunction is one of the first cellular changes seen in DMD myofibers, occurring prior to muscle disease onset and progresses with disease severity. This is seen by reduced mitochondrial function, abnormal mitochondrial morphology and impaired mitophagy (degradation of damaged mitochondria). Dysfunctional mitochondria release high levels of reactive oxygen species (ROS), which can activate pro-inflammatory pathways such as IL-1β and IL-6. Impaired mitophagy in DMD results in increased inflammation and further aggravates disease pathology, evidenced by increased muscle damage and increased fibrosis. This review will focus on the critical interplay between mitophagy and inflammation in Duchenne muscular dystrophy as a pathological mechanism, as well as describe both candidate and established therapeutic targets that regulate these pathways.

scholarly journals Duchenne Muscular Dystrophy - Family in a Crisis

1970 ◽  
pp. 36-39
Author(s):  
M Robed Amin ◽  
Chowdhury Chironjib Borua ◽  
Kaji Shafiqul Alam ◽  
Fazle Rabbi Chowdhury ◽  
Rabiul Jahan Sarkar ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Case Series ◽  
Dystrophin Gene ◽  
Muscle Disease ◽  
Motor Neuron Diseases ◽  
Muscle Diseases ◽  
Progressive Muscle Weakness ◽  
Recessive Disorders ◽  
Dystrophin Protein

Progressive muscular weakness with deformity leading to crippled states develop due to musculoskeletal and neurological disorders. Sometimes it is difficult to differentiate between primary muscle disease and neurological disease. But there is some classical presentation of muscle diseases which have its own entity and thus can be clinically differentiated from neurological disorder especially spinal cord and motor neuron diseases. Muscular dystrophy is one of those disorder with distinct clinical features. Muscular dystrophy refers to a group of genetic, hereditary muscle diseases that cause progressive muscle weakness. Most types of MD are multi-system disorders with manifestations in body systems including skeletal system, the heart, gastrointestinal and nervous systems, endocrine glands, skin, eyes and other organs. Duchenne muscular dystrophy (DMD), is inherited in an X-linked recessive pattern, meaning that the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes, and is thus considered sex-linked. Males are therefore affected by X-linked recessive disorders much more often than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Duchenne muscular dystrophy and Backers muscular dystrophy are caused by mutations of the gene for the dystrophin protein and lead to an overabundance of the enzyme creatine kinase. The dystrophin gene is the largest gene in humans. In this case series a family with three brothers suffering from Duchenne muscular dystrophy is described and review with literature was done.   doi:10.3329/jom.v10i3.2015 J Medicine 2009; 10 (Supplement 1): 36-39

scholarly journals Increased dystrophin production with golodirsen in patients with Duchenne muscular dystrophy

Neurology ◽  
2020 ◽  
Vol 94 (21) ◽  
pp. e2270-e2282 ◽  
Author(s):  
Diane E. Frank ◽  
Frederick J. Schnell ◽  
Cody Akana ◽  
Saleh H. El-Husayni ◽  
Cody A. Desjardins ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Western Blot ◽  
Exon Skipping ◽  
Study Drug ◽  
Dose Titration ◽  
Open Label ◽  
Double Blind ◽  
Dystrophin Protein ◽  
Muscle Biopsies

ObjectiveTo report safety, pharmacokinetics, exon 53 skipping, and dystrophin expression in golodirsen-treated patients with Duchenne muscular dystrophy (DMD) amenable to exon 53 skipping.MethodsPart 1 was a randomized, double-blind, placebo-controlled, 12-week dose titration of once-weekly golodirsen; part 2 is an ongoing, open-label evaluation. Safety and pharmacokinetics were primary and secondary objectives of part 1. Primary biological outcome measures of part 2 were blinded exon skipping and dystrophin protein production on muscle biopsies (baseline, week 48) evaluated, respectively, using reverse transcription PCR and Western blot and immunohistochemistry.ResultsTwelve patients were randomized to receive golodirsen (n = 8) or placebo (n = 4) in part 1. All from part 1 plus 13 additional patients received 30 mg/kg golodirsen in part 2. Safety findings were consistent with those previously observed in pediatric patients with DMD. Most of the study drug was excreted within 4 hours following administration. A significant increase in exon 53 skipping was associated with ∼16-fold increase over baseline in dystrophin protein expression at week 48, with a mean percent normal dystrophin protein standard of 1.019% (range, 0.09%–4.30%). Sarcolemmal localization of dystrophin was demonstrated by significantly increased dystrophin-positive fibers (week 48, p < 0.001) and a positive correlation (Spearman r = 0.663; p < 0.001) with dystrophin protein change from baseline, measured by Western blot and immunohistochemistry.ConclusionGolodirsen was well-tolerated; muscle biopsies from golodirsen-treated patients showed increased exon 53 skipping, dystrophin production, and correct dystrophin sarcolemmal localization.Clinicaltrials.gov identifierNCT02310906.Classification of evidenceThis study provides Class I evidence that golodirsen is safe and Class IV evidence that it induces exon skipping and novel dystrophin as confirmed by 3 different assays.

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