Exon Skipping Therapy Using Phosphorodiamidate Morpholino Oligomers in the mdx52 Mouse Model of Duchenne Muscular Dystrophy

2017 ◽  
pp. 123-141 ◽  
Author(s):  
Shouta Miyatake ◽  
Yoshitaka Mizobe ◽  
Hotake Takizawa ◽  
Yuko Hara ◽  
Toshifumi Yokota ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Exon Skipping ◽  
Phosphorodiamidate Morpholino Oligomers

WED 237 Phosphorodiamidate morpholino oligomers for treatment of duchenne muscular dystrophy

2018 ◽  
Vol 89 (10) ◽  
pp. A34.2-A34
Author(s):  
Maresh Kate ◽  
Tiet May ◽  
Guglieri Michela ◽  
Domingos Joana ◽  
Straub Volker ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Western Blot ◽  
Clinical Studies ◽  
Novel Mutation ◽  
Cumulative Risk ◽  
Exon Skipping ◽  
Dystrophin Expression ◽  
Polymerase Chain ◽  
Phosphorodiamidate Morpholino Oligomers

Exon skipping is a novel, mutation-specific approach to treating patients with Duchenne muscular dystrophy (DMD). Phosphorodiamidate morpholino oligomers are nucleic acid analogues that selectively redirect pre-mRNA splicing to enable production of internally truncated dystrophin.In exon 51 skipping (eteplirsen; n=36) and exon 53 skipping (golodirsen; n=25) clinical studies, internally shortened dystrophin mRNA was observed in all treated patients (per reverse transcription polymerase chain reaction). Eteplirsen increased dystrophin expression 15.5-fold, 11.6-fold, and 2.4-fold vs untreated controls (percent dystrophin-positive fibres, Western blot, and immunohistochemistry intensity, respectively; all, p≤0.007) in a 180 week study, and 2.8-fold (Western blot; p=0.008) in a 48 week study. Golodirsen increased dystrophin expression 10.7-fold (Western blot) over baseline following 48 weeks of treatment. Over 4 years, versus comparable external controls, eteplirsen slowed ambulatory decline (6 min walk test difference, 165 m; p=0.001) and cumulative risk of losing ambulation (83% vs 17%). In 2 clinical studies that included non-ambulatory patients, eteplirsen slowed pulmonary decline versus natural history data (assessed by spirometry).Eteplirsen and golodirsen demonstrated clinical and biochemical effects in patients with DMD; ongoing studies of these compounds are further characterising their effects in various patient populations.

scholarly journals Cyclic Peptides to Improve Delivery and Exon Skipping of Antisense Oligonucleotides in a Mouse Model for Duchenne Muscular Dystrophy

2018 ◽  
Vol 26 (1) ◽  
pp. 132-147 ◽  
Author(s):  
Silvana M.G. Jirka ◽  
Peter A.C. ’t Hoen ◽  
Valeriano Diaz Parillas ◽  
Christa L. Tanganyika-de Winter ◽  
Ruurd C. Verheul ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Mouse Model ◽  
Antisense Oligonucleotides ◽  
Cyclic Peptides ◽  
Exon Skipping

scholarly journals Single Exon Skipping Can Address a Multi-Exon Duplication in the Dystrophin Gene

2020 ◽  
Vol 21 (12) ◽  
pp. 4511 ◽  
Author(s):  
Kane Greer ◽  
Russell Johnsen ◽  
Yoram Nevo ◽  
Yakov Fellig ◽  
Susan Fletcher ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Duchenne Muscular Dystrophy Patient ◽  
Exon Duplication ◽  
Dmd Gene ◽  
Muscle Wasting Disease ◽  
Phosphorodiamidate Morpholino Oligomers

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disease typically caused by protein-truncating mutations that preclude synthesis of a functional dystrophin. Exonic deletions are the most common type of DMD lesion, however, whole exon duplications account for between 10–15% of all reported mutations. Here, we describe in vitro evaluation of antisense oligonucleotide-induced splice switching strategies to re-frame the transcript disrupted by a multi-exon duplication within the DMD gene. Phosphorodiamidate morpholino oligomers and phosphorodiamidate morpholino oligomers coupled to a cell penetrating peptide were evaluated in a Duchenne muscular dystrophy patient cell strain carrying an exon 14–17 duplication. Two strategies were employed; the conventional approach was to remove both copies of exon 17 in addition to exon 18, and the second strategy was to remove only the first copy of exon 17. Both approaches result in a larger than normal but in-frame DMD transcript, but surprisingly, the removal of only the first exon 17 appeared to be more efficient in restoring dystrophin, as determined using western blotting. The emergence of a normal sized DMD mRNA transcript that was not apparent in untreated samples may have arisen from back splicing and could also account for some of the dystrophin protein being produced.

scholarly journals Evaluating the potential of novel genetic approaches for the treatment of Duchenne muscular dystrophy

2021 ◽  
Author(s):  
Vratko Himič ◽  
Kay E. Davies
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Structural Integrity ◽  
Viral Vector ◽  
Exon Skipping ◽  
Dystrophin Gene ◽  
Pharmacological Treatments ◽  
Genetic Sequencing ◽  
Reading Frame ◽  
Target Effects

AbstractDuchenne muscular dystrophy (DMD) is an X-linked progressive muscle-wasting disorder that is caused by a lack of functional dystrophin, a cytoplasmic protein necessary for the structural integrity of muscle. As variants in the dystrophin gene lead to a disruption of the reading frame, pharmacological treatments have only limited efficacy; there is currently no effective therapy and consequently, a significant unmet clinical need for DMD. Recently, novel genetic approaches have shown real promise in treating DMD, with advancements in the efficacy and tropism of exon skipping and surrogate gene therapy. CRISPR-Cas9 has the potential to be a ‘one-hit’ curative treatment in the coming decade. The current limitations of gene editing, such as off-target effects and immunogenicity, are in fact partly constraints of the delivery method itself, and thus research focus has shifted to improving the viral vector. In order to halt the loss of ambulation, early diagnosis and treatment will be pivotal. In an era where genetic sequencing is increasingly utilised in the clinic, genetic therapies will play a progressively central role in DMD therapy. This review delineates the relative merits of cutting-edge genetic approaches, as well as the challenges that still need to be overcome before they become clinically viable.

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