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Aldharee H. Duchenne muscular dystrophy in Saudi Arabia: a review of the current literature. Front Neurol 2024; 15:1392274. [PMID: 39087004 PMCID: PMC11288836 DOI: 10.3389/fneur.2024.1392274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 07/08/2024] [Indexed: 08/02/2024] Open
Abstract
In the past three decades, significant improvements have occurred in the study of Duchenne muscular dystrophy (DMD). DMD is a rare, severe neuromuscular disease that causes death due to cardiovascular and respiratory complications among affected boys. Since the 1980s, ongoing preclinical and clinical studies have been conducted to explore the disease in depth and discover potential therapeutic strategies. In Saudi Arabia, it is unclear whether health services and research efforts are keeping pace with global achievements. Therefore, this review aims to explore the diagnostic and management strategies and research efforts in Saudi Arabia over the past three decades. I searched the PubMed/Medline, Scopus, and Web of Science databases and included all published articles on the epidemiology, genetics, diagnosis, and management of DMD/BMD in this review. The findings suggest a lack of local standardized diagnostic strategies, a poor understanding of epidemiology and common pathogenic variants, and a critical need for preclinical and clinical research. At the time of writing, no such comprehensive review has been published. Challenges, limitations, and future perspectives are also discussed in this article.
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Affiliation(s)
- Hitham Aldharee
- Department of Pathology, College of Medicine, Qassim University, Buraidah, Saudi Arabia
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Gandhi S, Sweeney HL, Hart CC, Han R, Perry CGR. Cardiomyopathy in Duchenne Muscular Dystrophy and the Potential for Mitochondrial Therapeutics to Improve Treatment Response. Cells 2024; 13:1168. [PMID: 39056750 PMCID: PMC11274633 DOI: 10.3390/cells13141168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 07/05/2024] [Accepted: 07/06/2024] [Indexed: 07/28/2024] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease caused by mutations to the dystrophin gene, resulting in deficiency of dystrophin protein, loss of myofiber integrity in skeletal and cardiac muscle, and eventual cell death and replacement with fibrotic tissue. Pathologic cardiac manifestations occur in nearly every DMD patient, with the development of cardiomyopathy-the leading cause of death-inevitable by adulthood. As early cardiac abnormalities are difficult to detect, timely diagnosis and appropriate treatment modalities remain a challenge. There is no cure for DMD; treatment is aimed at delaying disease progression and alleviating symptoms. A comprehensive understanding of the pathophysiological mechanisms is crucial to the development of targeted treatments. While established hypotheses of underlying mechanisms include sarcolemmal weakening, upregulation of pro-inflammatory cytokines, and perturbed ion homeostasis, mitochondrial dysfunction is thought to be a potential key contributor. Several experimental compounds targeting the skeletal muscle pathology of DMD are in development, but the effects of such agents on cardiac function remain unclear. The synergistic integration of small molecule- and gene-target-based drugs with metabolic-, immune-, or ion balance-enhancing compounds into a combinatorial therapy offers potential for treating dystrophin deficiency-induced cardiomyopathy, making it crucial to understand the underlying mechanisms driving the disorder.
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Affiliation(s)
- Shivam Gandhi
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON M3J 1P3, Canada
| | - H. Lee Sweeney
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA; (H.L.S.); (C.C.H.)
- Myology Institute, University of Florida, Gainesville, FL 32610, USA
| | - Cora C. Hart
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA; (H.L.S.); (C.C.H.)
- Myology Institute, University of Florida, Gainesville, FL 32610, USA
| | - Renzhi Han
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | - Christopher G. R. Perry
- School of Kinesiology and Health Science, Muscle Health Research Centre, York University, Toronto, ON M3J 1P3, Canada
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Tang A, Yokota T. Duchenne muscular dystrophy: promising early-stage clinical trials to watch. Expert Opin Investig Drugs 2024; 33:201-217. [PMID: 38291016 DOI: 10.1080/13543784.2024.2313105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 01/28/2024] [Indexed: 02/01/2024]
Abstract
INTRODUCTION Current therapies are unable to cure Duchenne muscular dystrophy (DMD), a severe and common form of muscular dystrophy, and instead aim to delay disease progression. Several treatments currently in phase I trials could increase the number of therapeutic options available to patients. AREAS COVERED This review aims to provide an overview of current treatments undergoing or having recently undergone early-stage trials. Several exon-skipping and gene therapy approaches are currently being investigated at the clinical stage to address an unmet need for DMD treatments. This article also covers Phase I trials from the last 5 years that involve inhibitors, small molecules, a purified synthetic flavanol, a cell-based therapy, and repurposed cardiac or tumor medications. EXPERT OPINION With antisense oligonucleotide (AON) treatments making up the majority of conditionally approved DMD therapies, most of the clinical trials occurring within the last 5 years have also evaluated exon-skipping AONs. The approval of Elevidys, a micro-dystrophin therapy, is reflected in a recent trend toward gene transfer therapies in phase I DMD clinical trials, but their safety and efficacy are being established in this phase of development. Other Phase I clinical-stage approaches are diverse, but have a range in efficacy, safety, and endpoint measures.
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Affiliation(s)
- Annie Tang
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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Fortunato F, Tonelli L, Farnè M, Selvatici R, Ferlini A. DMD deletions underlining mild dystrophinopathies: literature review highlights phenotype-related mutation clusters and provides insights about genetic mechanisms and prognosis. Front Neurol 2024; 14:1288721. [PMID: 38288333 PMCID: PMC10823016 DOI: 10.3389/fneur.2023.1288721] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/27/2023] [Indexed: 01/31/2024] Open
Abstract
DMD gene pathogenic variations cause a spectrum of phenotypes, ranging from severe Duchenne muscular dystrophy, the Becker milder cases, the intermediate or very mild muscle phenotypes invariably characterized by high CK, and the ultrarare fully-asymptomatic cases. Besides these phenotypes, X-linked dilated cardiomyopathy is also caused by DMD mutations. Males carrying DMD deletions with absent or very mild phenotypes have been sparsely described. We performed a horizon scan on public datasets to enroll males with the above phenotypes and carrying DMD deletions to delineate myopathic genotype-phenotype relationships. We inventoried 81 males, who were divided into the following clinical categorization: fully-asymptomatic males aged >43 years (A, N = 22); isolated hyperCKemia (CK, N = 35); and mild weakness (any age) with or without high CK (WCK, N = 24). In all cases, deleted intervals were exons 2 to 55, and no downstream exons were ever involved, apart from an exon 78 deletion in a WCK patient. All deletions were in-frame apart from the known exception to the rule of exon 2 and exon 78. We correlated the mild phenotypes (A and CK) to deleted exons, intronic breakpoints, exon-exon junctions, 3' isoforms rule, and protein epitopes, and we found that some genetic profiles are exclusively/mainly occurring in A/CK phenotypes, suggesting they are compatible with a quasi-normal muscular performance. We discussed diverse pathogenic mechanisms that may contribute to mild dystrophinopathic phenotypes, and we tried to address some "critical" genetic configurations or exon content needed to preserve a semi-functional DMD gene.
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Affiliation(s)
| | | | | | | | - Alessandra Ferlini
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
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Saad FA, Saad JF, Siciliano G, Merlini L, Angelini C. Duchenne Muscular Dystrophy Gene Therapy. Curr Gene Ther 2024; 24:17-28. [PMID: 36411557 DOI: 10.2174/1566523223666221118160932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 09/27/2022] [Accepted: 10/11/2022] [Indexed: 11/23/2022]
Abstract
Duchenne and Becker muscular dystrophies are allelic X-linked recessive neuromuscular diseases affecting both skeletal and cardiac muscles. Therefore, owing to their single X chromosome, the affected boys receive pathogenic gene mutations from their unknowing carrier mothers. Current pharmacological drugs are palliative that address the symptoms of the disease rather than the genetic cause imbedded in the Dystrophin gene DNA sequence. Therefore, alternative therapies like gene drugs that could address the genetic cause of the disease at its root are crucial, which include gene transfer/implantation, exon skipping, and gene editing. Presently, it is possible through genetic reprogramming to engineer AAV vectors to deliver certain therapeutic cargos specifically to muscle or other organs regardless of their serotype. Similarly, it is possible to direct the biogenesis of exosomes to carry gene editing constituents or certain therapeutic cargos to specific tissue or cell type like brain and muscle. While autologous exosomes are immunologically inert, it is possible to camouflage AAV capsids, and lipid nanoparticles to evade the immune system recognition. In this review, we highlight current opportunities for Duchenne muscular dystrophy gene therapy, which has been known thus far as an incurable genetic disease. This article is a part of Gene Therapy of Rare Genetic Diseases thematic issue.
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Affiliation(s)
- Fawzy A Saad
- Department of Biology, Padua University School of Medicine, Via Trieste 75, Padova 35121, Italy
- Department of Gene Therapy, Saad Pharmaceuticals, Tornimäe 7-26, Tallinn, 10145, Estonia
| | - Jasen F Saad
- Department of Gene Therapy, Saad Pharmaceuticals, Tornimäe 7-26, Tallinn, 10145, Estonia
| | - Gabriele Siciliano
- Department of Clinical and Experimental Medicine, Pisa University School of Medicine, Pisa, Italy
| | - Luciano Merlini
- Department of Biomedical and Neuromotor Sciences, Bologna University School of Medicine, 40126 Bologna, Italy
| | - Corrado Angelini
- Department Neurosciences, Padova University School of Medicine, Padova, Italy
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Shiba N, Yang X, Sato M, Kadota S, Suzuki Y, Agata M, Nagamine K, Izumi M, Honda Y, Koganehira T, Kobayashi H, Ichimura H, Chuma S, Nakai J, Tohyama S, Fukuda K, Miyazaki D, Nakamura A, Shiba Y. Efficacy of exon-skipping therapy for DMD cardiomyopathy with mutations in actin binding domain 1. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 34:102060. [PMID: 38028197 PMCID: PMC10654596 DOI: 10.1016/j.omtn.2023.102060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 10/17/2023] [Indexed: 12/01/2023]
Abstract
Exon-skipping therapy is a promising treatment strategy for Duchenne muscular dystrophy (DMD), which is caused by loss-of-function mutations in the DMD gene encoding dystrophin, leading to progressive cardiomyopathy. In-frame deletion of exons 3-9 (Δ3-9), manifesting a very mild clinical phenotype, is a potential targeted reading frame for exon-skipping by targeting actin-binding domain 1 (ABD1); however, the efficacy of this approach for DMD cardiomyopathy remains uncertain. In this study, we compared three isogenic human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) expressing Δ3-9, frameshifting Δ3-7, or intact DMD. RNA sequencing revealed a resemblance in the expression patterns of mechano-transduction-related genes between Δ3-9 and wild-type samples. Furthermore, we observed similar electrophysiological properties between Δ3-9 and wild-type hiPSC-CMs; Δ3-7 hiPSC-CMs showed electrophysiological alterations with accelerated CaMKII activation. Consistently, Δ3-9 hiPSC-CMs expressed substantial internally truncated dystrophin protein, resulting in maintaining F-actin binding and desmin retention. Antisense oligonucleotides targeting exon 8 efficiently induced skipping exons 8-9 to restore functional dystrophin and electrophysiological parameters in Δ3-7 hiPSC-CMs, bringing the cell characteristics closer to those of Δ3-9 hiPSC-CMs. Collectively, exon-skipping targeting ABD1 to convert the reading frame to Δ3-9 may become a promising therapy for DMD cardiomyopathy.
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Affiliation(s)
- Naoko Shiba
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
- Department of Pediatrics, Shinshu University, Matsumoto 390-8621, Japan
| | - Xiao Yang
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Mitsuto Sato
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Shin Kadota
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
- Institute for Biomedical Sciences, Shinshu University, Matsumoto 390-8621, Japan
| | - Yota Suzuki
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Masahiro Agata
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Kohei Nagamine
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Masaki Izumi
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Yusuke Honda
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Tomoya Koganehira
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Hideki Kobayashi
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Hajime Ichimura
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
| | - Shinichiro Chuma
- Department of Regeneration Science and Engineering, Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Junichi Nakai
- Graduate Schools of Dentistry, Tohoku University, Sendai 980-8575, Japan
| | - Shugo Tohyama
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Daigo Miyazaki
- Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto 390-8621, Japan
| | - Akinori Nakamura
- Department of Clinical Research, National Hospital Organization Matsumoto Medical Center, Matsumoto 399-8701, Japan
| | - Yuji Shiba
- Department of Regenerative Science and Medicine, Shinshu University, Matsumoto 390-8621, Japan
- Institute for Biomedical Sciences, Shinshu University, Matsumoto 390-8621, Japan
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Nakamura A, Matsumura T, Ogata K, Mori‐Yoshimura M, Takeshita E, Kimura K, Kawashima T, Tomo Y, Arahata H, Miyazaki D, Takeshima Y, Takahashi T, Ishigaki K, Kuru S, Wakisaka A, Awano H, Funato M, Sato T, Saito Y, Takada H, Sugie K, Kobayashi M, Ozasa S, Fujii T, Maegaki Y, Oi H, Tachimori H, Komaki H. Natural history of Becker muscular dystrophy: a multicenter study of 225 patients. Ann Clin Transl Neurol 2023; 10:2360-2372. [PMID: 37882106 PMCID: PMC10723226 DOI: 10.1002/acn3.51925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 10/02/2023] [Indexed: 10/27/2023] Open
Abstract
OBJECTIVE Becker muscular dystrophy (BMD) is a milder variant of Duchenne muscular dystrophy (DMD), a lethal X-linked muscular disorder. Here, we aim to investigat the clinical involvement of skeletal, respiratory, cardiac, and central nervous systems in patients with BMD, as well as genotype-phenotype relationships. METHODS This nationwide cohort study investigated the clinical manifestations and genotype-phenotype relationships in 225 patients with BMD having in-frame deletion from 22 medical centers. The primary outcome was to elucidate the association of genotype with skeletal muscle, respiratory, cardiac, and central nervous system disorders. Descriptive statistics were used to analyze the data. RESULTS The average age of the subjects was 31.5 (range, 1-81) years. Initial symptoms of BMD were muscular (60%), followed by asymptomatic hypercreatine kinasemia (32.4%) and central nervous system disorders (5.3%). Gait disturbance was observed in 53.8% of patients and the average age at wheelchair introduction was 36.5 years. The ventilator introduction rate was 6.7% at an average age of 36.6 years. More than 30% of patients had an abnormal electrocardiogram and approximately 15% had heart failure symptoms. Cardiac function on echocardiography varied significantly among the patients. The frequencies of seizures and intellectual/developmental disability were 8.0% and 16.9%, respectively. Exon 45-47deletion (del) was the most common (22.6%), followed by exon 45-48del (13.1%). Patients with exon 45-49del patients demonstrated severe skeletal muscle damage. Patients with exon 45-47del and exon 45-55del patients did not require ventilator use. INTERPRETATION The study provides important prognostic information for patients and clinicians to establish therapy plans and to implement preventative medicine.
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Affiliation(s)
- Akinori Nakamura
- Department of NeurologyNHO Matsumoto Medical CenterMatsumotoJapan
| | | | - Katsuhisa Ogata
- Department of NeurologyNHO Higashisaitama National HospitalHasudaJapan
| | - Madoka Mori‐Yoshimura
- Department of NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
| | - Eri Takeshita
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
| | - Koichi Kimura
- Department of Laboratory Medicine/CardiologyThe Institute of Medical Science, The University of TokyoMinato‐kuJapan
| | - Takahiro Kawashima
- Department of Information Medicine, National Center of Neurology and PsychiatryNational Institute of NeuroscienceKodairaJapan
| | - Yui Tomo
- Department of Clinical Data Science, Clinical Research & Education Promotion Division, National Center of Neurology and PsychiatryKodairaJapan
| | - Hajime Arahata
- Department of Neurology, Neuro‐Muscular CenterNHO Omuta National HospitalOmutaJapan
| | - Daigo Miyazaki
- Department of Medicine (Neurology and Rheumatology)Shinshu University School of MedicineMatsumotoJapan
| | - Yasuhiro Takeshima
- Department of PediatricsHyogo Medical University School of MedicineNishinomiyaJapan
| | | | - Keiko Ishigaki
- Department of PediatricsTokyo Women's Medical University School of MedicineShinjuku‐kuJapan
| | - Satoshi Kuru
- Department of NeurologyNHO Suzuka National HospitalSuzukaJapan
| | - Akiko Wakisaka
- Department of PediatricsNHO Iou National HospitalKanazawaJapan
| | - Hiroyuki Awano
- Research Initiative Center, Organization for Research Initiative and PromotionTottori UniversityYonagoJapan
| | - Michinori Funato
- Department of Pediatric NeurologyNHO Nagara Medical CenterNagaraJapan
| | - Tatsuharu Sato
- Department of PediatricsNagasaki University HospitalNagasakiJapan
| | - Yoshiaki Saito
- Department of PediatricsNational Rehabilitation Center for Children with DisabilitiesItabashiJapan
| | - Hiroto Takada
- Department of NeurologyNHO Aomori National HospitalAomoriJapan
| | - Kazuma Sugie
- Department of NeurologyNara Medical University School of MedicineKashiharaJapan
| | - Michio Kobayashi
- Department of NeurologyNHO Akita National HospitalYurihonjoJapan
| | - Shiro Ozasa
- Department of PediatricsKumamoto University HospitalKumamotoJapan
| | - Tatsuya Fujii
- Department of PediatricsShiga Medical Center for ChildrenMoriyamaJapan
| | - Yoshihiro Maegaki
- Division of Child Neurology, Department of Brain and Neurosciences, Faculty of MedicineTottori UniversityYonagoJapan
| | - Hideki Oi
- Department of Clinical Data Science, Clinical Research & Education Promotion Division, National Center of Neurology and PsychiatryKodairaJapan
| | - Hisateru Tachimori
- Department of Information Medicine, National Center of Neurology and PsychiatryNational Institute of NeuroscienceKodairaJapan
- Endowed Course of Health System InnovationKeio University School of MedicineTokyoJapan
| | - Hirofumi Komaki
- Department of Child NeurologyNational Center Hospital, National Center of Neurology and PsychiatryKodairaJapan
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Roberts TC, Wood MJA, Davies KE. Therapeutic approaches for Duchenne muscular dystrophy. Nat Rev Drug Discov 2023; 22:917-934. [PMID: 37652974 DOI: 10.1038/s41573-023-00775-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2023] [Indexed: 09/02/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a monogenic muscle-wasting disorder and a priority candidate for molecular and cellular therapeutics. Although rare, it is the most common inherited myopathy affecting children and so has been the focus of intense research activity. It is caused by mutations that disrupt production of the dystrophin protein, and a plethora of drug development approaches are under way that aim to restore dystrophin function, including exon skipping, stop codon readthrough, gene replacement, cell therapy and gene editing. These efforts have led to the clinical approval of four exon skipping antisense oligonucleotides, one stop codon readthrough drug and one gene therapy product, with other approvals likely soon. Here, we discuss the latest therapeutic strategies that are under development and being deployed to treat DMD. Lessons from these drug development programmes are likely to have a major impact on the DMD field, but also on molecular and cellular medicine more generally. Thus, DMD is a pioneer disease at the forefront of future drug discovery efforts, with these experimental treatments paving the way for therapies using similar mechanisms of action being developed for other genetic diseases.
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Affiliation(s)
- Thomas C Roberts
- Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK.
- Department of Paediatrics, University of Oxford, Oxford, UK.
- MDUK Oxford Neuromuscular Centre, Oxford, UK.
| | - Matthew J A Wood
- Institute of Developmental and Regenerative Medicine, University of Oxford, Oxford, UK
- Department of Paediatrics, University of Oxford, Oxford, UK
- MDUK Oxford Neuromuscular Centre, Oxford, UK
| | - Kay E Davies
- MDUK Oxford Neuromuscular Centre, Oxford, UK.
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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Egorova TV, Polikarpova AV, Vassilieva SG, Dzhenkova MA, Savchenko IM, Velyaev OA, Shmidt AA, Soldatov VO, Pokrovskii MV, Deykin AV, Bardina MV. CRISPR-Cas9 correction in the DMD mouse model is accompanied by upregulation of Dp71f protein. Mol Ther Methods Clin Dev 2023; 30:161-180. [PMID: 37457303 PMCID: PMC10339130 DOI: 10.1016/j.omtm.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a severe hereditary disease caused by a deficiency in the dystrophin protein. The most frequent types of disease-causing mutations in the DMD gene are frameshift deletions of one or more exons. Precision genome editing systems such as CRISPR-Cas9 have shown potential to restore open reading frames in numerous animal studies. Here, we applied an AAV-CRISPR double-cut strategy to correct a mutation in the DMD mouse model with exon 8-34 deletion, encompassing the N-terminal actin-binding domain. We report successful excision of the 100-kb genomic sequence, which includes exons 6 and 7, and partial improvement in cardiorespiratory function. While corrected mRNA was abundant in muscle tissues, only a low level of truncated dystrophin was produced, possibly because of protein instability. Furthermore, CRISPR-Cas9-mediated genome editing upregulated the Dp71f dystrophin isoform on the sarcolemma. Given the previously reported Dp71-associated muscle pathology, our results question the applicability of genome editing strategies for some DMD patients with N-terminal mutations. The safety and efficacy of CRISPR-Cas9 constructs require rigorous investigation in patient-specific animal models.
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Affiliation(s)
- Tatiana V. Egorova
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Marlin Biotech LLC, Sochi 354340, Russia
| | - Anna V. Polikarpova
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Marlin Biotech LLC, Sochi 354340, Russia
| | - Svetlana G. Vassilieva
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Marina A. Dzhenkova
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Irina M. Savchenko
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Oleg A. Velyaev
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Anna A. Shmidt
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
| | - Vladislav O. Soldatov
- Research Institute of Living Systems Pharmacology, Belgorod National Research University, Belgorod 308007, Russia
| | - Mikhail V. Pokrovskii
- Research Institute of Living Systems Pharmacology, Belgorod National Research University, Belgorod 308007, Russia
| | - Alexey V. Deykin
- Marlin Biotech LLC, Sochi 354340, Russia
- Joint Center for Genetic Technologies, Laboratory of Genetic Technologies and Gene Editing for Biomedicine and Veterinary Medicine, Department of Pharmacology and Clinical Pharmacology, Belgorod National Research University, Belgorod 308015, Russia
| | - Maryana V. Bardina
- Laboratory of Modeling and Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
- Marlin Biotech LLC, Sochi 354340, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology Russian Academy of Sciences, Moscow 119334, Russia
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10
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Genome Editing to Abrogate Muscle Atrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1396:157-176. [DOI: 10.1007/978-981-19-5642-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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11
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Wilton-Clark H, Yokota T. Biological and genetic therapies for the treatment of Duchenne muscular dystrophy. Expert Opin Biol Ther 2023; 23:49-59. [PMID: 36409820 DOI: 10.1080/14712598.2022.2150543] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Duchenne muscular dystrophy is a lethal genetic disease which currently has no cure, and poor standard treatment options largely focused on symptom relief. The development of multiple biological and genetic therapies is underway across various stages of clinical progress which could markedly affect how DMD patients are treated in the future. AREAS COVERED The purpose of this review is to provide an introduction to the different therapeutic modalities currently being studied, as well as a brief description of their progress to date and relative advantages and disadvantages for the treatment of DMD. This review discusses exon skipping therapy, microdystrophin therapy, stop codon readthrough therapy, CRISPR-based gene editing, cell-based therapy, and utrophin upregulation. Secondary therapies addressing nonspecific symptoms of DMD were excluded. EXPERT OPINION Despite the vast potential held by gene replacement therapy options such as microdystrophin production and utrophin upregulation, safety risks inherent to the adeno-associated virus delivery vector might hamper the clinical viability of these approaches until further improvements can be made. Of the mutation-specific therapies, exon skipping therapy remains the most extensively validated and explored option, and the cell-based CAP-1002 therapy may prove to be a suitable adjunct therapy filling the urgent need for cardiac-specific therapies.
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Affiliation(s)
- Harry Wilton-Clark
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Toshifumi Yokota
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
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12
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Çerçi B, Uzay IA, Kara MK, Dinçer P. Clinical trials and promising preclinical applications of CRISPR/Cas gene editing. Life Sci 2022; 312:121204. [PMID: 36403643 DOI: 10.1016/j.lfs.2022.121204] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/03/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022]
Abstract
Treatment of genetic disorders by genomic manipulation has been the unreachable goal of researchers for many decades. Although our understanding of the genetic basis of genetic diseases has advanced tremendously in the last few decades, the tools developed for genomic editing were not efficient and practical for their use in the clinical setting until now. The recent advancements in the research of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated protein (Cas) systems offered an easy and efficient way to edit the genome and accelerated the research on their potential use in the treatment of genetic disorders. In this review, we summarize the clinical trials that evaluate the CRISPR/Cas systems for treating different genetic diseases and highlight promising preclinical research on CRISPR/Cas mediated treatment of a great diversity of genetic disorders. Ultimately, we discuss the future of CRISPR/Cas mediated genome editing in genetic diseases.
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Affiliation(s)
- Barış Çerçi
- Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey.
| | - Ihsan Alp Uzay
- Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
| | | | - Pervin Dinçer
- Department of Medical Biology, Faculty of Medicine, Hacettepe University, Ankara 06100, Turkey
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13
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Den Hartog L, Asakura A. Implications of notch signaling in duchenne muscular dystrophy. Front Physiol 2022; 13:984373. [PMID: 36237531 PMCID: PMC9553129 DOI: 10.3389/fphys.2022.984373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
This review focuses upon the implications of the Notch signaling pathway in muscular dystrophies, particularly Duchenne muscular dystrophy (DMD): a pervasive and catastrophic condition concerned with skeletal muscle degeneration. Prior work has defined the pathogenesis of DMD, and several therapeutic approaches have been undertaken in order to regenerate skeletal muscle tissue and ameliorate the phenotype. There is presently no cure for DMD, but a promising avenue for novel therapies is inducing muscle regeneration via satellite cells (muscle stem cells). One specific target using this approach is the Notch signaling pathway. The canonical Notch signaling pathway has been well-characterized and it ultimately governs cell fate decision, cell proliferation, and induction of differentiation. Additionally, inhibition of the Notch signaling pathway has been directly implicated in the deficits seen with muscular dystrophies. Here, we explore the connection between the Notch signaling pathway and DMD, as well as how Notch signaling may be targeted to improve the muscle degeneration seen in muscular dystrophies.
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14
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Passos-Bueno MR, Costa CIS, Zatz M. Dystrophin genetic variants and autism. DISCOVER MENTAL HEALTH 2022; 2:4. [PMID: 37861890 PMCID: PMC10501027 DOI: 10.1007/s44192-022-00008-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/07/2022] [Indexed: 10/21/2023]
Abstract
Loss-of-function variants in the dystrophin gene, a well-known cause of muscular dystrophies, have emerged as a mutational risk mechanism for autism spectrum disorder (ASD), which in turn is a highly prevalent (~ 1%) genetically heterogeneous neurodevelopmental disorder. Although the association of intellectual disability with the dystrophinopathies Duchenne (DMD) and Becker muscular dystrophy (BMD) has been long established, their association with ASD is more recent, and the dystrophin genotype-ASD phenotype correlation is unclear. We therefore present a review of the literature focused on the ASD prevalence among dystrophinopathies, the relevance of the dystrophin isoforms, and most particularly the relevance of the genetic background to the etiology of ASD in these patients. Four families with ASD-DMD/BMD patients are also reported here for the first time. These include a single ASD individual, ASD-discordant and ASD-concordant monozygotic twins, and non-identical ASD triplets. Notably, two unrelated individuals, which were first ascertained because of the ASD phenotype at ages 15 and 5 years respectively, present rare dystrophin variants still poorly characterized, suggesting that some dystrophin variants may compromise the brain more prominently. Whole exome sequencing in these ASD-DMD/BMD individuals together with the literature suggest, although based on preliminary data, a complex and heterogeneous genetic architecture underlying ASD in dystrophinopathies, that include rare variants of large and medium effect. The need for the establishment of a consortia for genomic investigation of ASD-DMD/BMD patients, which may shed light on the genetic architecture of ASD, is discussed.
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Affiliation(s)
- Maria Rita Passos-Bueno
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil.
| | - Claudia Ismania Samogy Costa
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Mayana Zatz
- Departamento de Genética e Biologia Evolutiva, Centro de Estudos do Genoma Humano e Células-Tronco, Instituto de Biociências, Universidade de São Paulo, São Paulo, SP, Brazil
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15
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Antisense and Gene Therapy Options for Duchenne Muscular Dystrophy Arising from Mutations in the N-Terminal Hotspot. Genes (Basel) 2022; 13:genes13020257. [PMID: 35205302 PMCID: PMC8872079 DOI: 10.3390/genes13020257] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 02/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a fatal genetic disease affecting children that is caused by a mutation in the gene encoding for dystrophin. In the absence of functional dystrophin, patients experience progressive muscle deterioration, leaving them wheelchair-bound by age 12 and with few patients surviving beyond their third decade of life as the disease advances and causes cardiac and respiratory difficulties. In recent years, an increasing number of antisense and gene therapies have been studied for the treatment of muscular dystrophy; however, few of these therapies focus on treating mutations arising in the N-terminal encoding region of the dystrophin gene. This review summarizes the current state of development of N-terminal antisense and gene therapies for DMD, mainly focusing on exon-skipping therapy for duplications and deletions, as well as microdystrophin therapy.
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16
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Matsuzaka Y, Hirai Y, Hashido K, Okada T. Therapeutic Application of Extracellular Vesicles-Capsulated Adeno-Associated Virus Vector via nSMase2/Smpd3, Satellite, and Immune Cells in Duchenne Muscular Dystrophy. Int J Mol Sci 2022; 23:ijms23031551. [PMID: 35163475 PMCID: PMC8836108 DOI: 10.3390/ijms23031551] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 02/04/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is caused by loss-of-function mutations in the dystrophin gene on chromosome Xp21. Disruption of the dystrophin–glycoprotein complex (DGC) on the cell membrane causes cytosolic Ca2+ influx, resulting in protease activation, mitochondrial dysfunction, and progressive myofiber degeneration, leading to muscle wasting and fragility. In addition to the function of dystrophin in the structural integrity of myofibers, a novel function of asymmetric cell division in muscular stem cells (satellite cells) has been reported. Therefore, it has been suggested that myofiber instability may not be the only cause of dystrophic degeneration, but rather that the phenotype might be caused by multiple factors, including stem cell and myofiber functions. Furthermore, it has been focused functional regulation of satellite cells by intracellular communication of extracellular vesicles (EVs) in DMD pathology. Recently, a novel molecular mechanism of DMD pathogenesis—circulating RNA molecules—has been revealed through the study of target pathways modulated by the Neutral sphingomyelinase2/Neutral sphingomyelinase3 (nSMase2/Smpd3) protein. In addition, adeno-associated virus (AAV) has been clinically applied for DMD therapy owing to the safety and long-term expression of transduction genes. Furthermore, the EV-capsulated AAV vector (EV-AAV) has been shown to be a useful tool for the intervention of DMD, because of the high efficacy of the transgene and avoidance of neutralizing antibodies. Thus, we review application of AAV and EV-AAV vectors for DMD as novel therapeutic strategy.
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Affiliation(s)
- Yasunari Matsuzaka
- Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan;
- Administrative Section of Radiation Protection, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan;
- Correspondence: (Y.M.); (T.O.); Tel.: +81-3-5449-5372 (Y.M. & T.O.)
| | - Yukihiko Hirai
- Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan;
| | - Kazuo Hashido
- Administrative Section of Radiation Protection, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8551, Japan;
| | - Takashi Okada
- Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo 108-8639, Japan;
- Correspondence: (Y.M.); (T.O.); Tel.: +81-3-5449-5372 (Y.M. & T.O.)
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17
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Salzer‐Sheelo L, Fellner A, Orenstein N, Bazak L, Lev‐El Halabi N, Daue M, Smirin‐Yosef P, Van Hout CV, Fellig Y, Ruhrman‐Shahar N, Staples J, Magal N, Shuldiner AR, Mitchell BD, Nevo Y, Pollin TI, Gonzaga‐Jauregui C, Basel‐Salmon L. Biallelic Truncating Variants in the Muscular A‐Type Lamin‐Interacting Protein (
MLIP
) Gene Cause Myopathy with Hyper‐CKemia. Eur J Neurol 2021; 29:1174-1180. [DOI: 10.1111/ene.15218] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 12/02/2021] [Accepted: 12/10/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Liat Salzer‐Sheelo
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
- Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
| | - Avi Fellner
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
- Department of Neurology Rabin Medical Center Beilinson Hospital Petah Tikva Israel
| | - Naama Orenstein
- Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Pediatric Genetics Clinic Schneider Children’s Medical Center of Israel Petah Tikva Israel
| | - Lily Bazak
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
| | - Noa Lev‐El Halabi
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
| | - Melanie Daue
- Division of Endocrinology Diabetes & Nutrition Department of Medicine University of Maryland School of Medicine Baltimore MD USA
| | - Pola Smirin‐Yosef
- Genomic Bioinformatics Laboratory Department of Molecular Biology Ariel University Israel
- Felsenstein Medical Research Center Rabin Medical Center Petah Tikva Israel
| | | | - Yakov Fellig
- Department of Pathology Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem Israel
| | - Noa Ruhrman‐Shahar
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
| | | | - Nurit Magal
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
| | | | - Braxton D. Mitchell
- Division of Endocrinology Diabetes & Nutrition Department of Medicine University of Maryland School of Medicine Baltimore MD USA
| | - Yoram Nevo
- Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Pediatric Neurology Unit Schneider Children’s Medical Center of Israel Petah Tikva Israel
| | - Toni I. Pollin
- Division of Endocrinology Diabetes & Nutrition Department of Medicine University of Maryland School of Medicine Baltimore MD USA
| | - Claudia Gonzaga‐Jauregui
- Regeneron Genetics Center Tarrytown NY USA
- International Laboratory for Human Genome Research Laboratorio Internacional de Investigación sobre el Genoma Humano Universidad Nacional Autónoma de México Juriquilla Querétaro Mexico
| | - Lina Basel‐Salmon
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital Petah Tikva Israel
- Sackler Faculty of Medicine Tel Aviv University Tel Aviv Israel
- Felsenstein Medical Research Center Rabin Medical Center Petah Tikva Israel
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18
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Maruyama R, Yokota T. Antisense Oligonucleotide Treatment in a Humanized Mouse Model of Duchenne Muscular Dystrophy and Highly Sensitive Detection of Dystrophin Using Western Blotting. Methods Mol Biol 2021; 2224:203-214. [PMID: 33606217 DOI: 10.1007/978-1-0716-1008-4_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating X-linked muscle disorder affecting many children. The disease is caused by the lack of dystrophin production and characterized by muscle wasting. The most common causes of death are respiratory failure and heart failure. Antisense oligonucleotide-mediated exon skipping using a phosphorodiamidate morpholino oligomer (PMO) is a promising therapeutic approach for the treatment of DMD. In preclinical studies, dystrophic mouse models are commonly used for the development of therapeutic oligos. We employ a humanized model carrying the full-length human DMD transgene along with the complete knockout of the mouse Dmd gene. In this model, the effects of human-targeting AOs can be tested without cross-reaction between mouse sequences and human sequences (note that mdx, a conventional dystrophic mouse model, carries a nonsense point mutation in exon 23 and express the full-length mouse Dmd mRNA, which is a significant complicating factor). To determine if dystrophin expression is restored, the Western blotting analysis is commonly performed; however, due to the extremely large protein size of dystrophin (427 kDa), detection and accurate quantification of full-length dystrophin can be a challenge. Here, we present methodologies to systemically inject PMOs into humanized DMD model mice and determine levels of dystrophin restoration via Western blotting. Using a tris-acetate gradient SDS gel and semi-dry transfer with three buffers, including the Concentrated Anode Buffer, Anode Buffer, and Cathode Buffer, less than 1% normal levels of dystrophin expression are easily detectable. This method is fast, easy, and sensitive enough for the detection of dystrophin from both cultured muscle cells and muscle biopsy samples.
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Affiliation(s)
- Rika Maruyama
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Faculty of Medicine and Dentistry, Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada. .,The Friends of Garrett Cumming Research & Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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19
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Mollanoori H, Rahmati Y, Hassani B, Havasi Mehr M, Teimourian S. Promising therapeutic approaches using CRISPR/Cas9 genome editing technology in the treatment of Duchenne muscular dystrophy. Genes Dis 2021; 8:146-156. [PMID: 33997161 PMCID: PMC8099695 DOI: 10.1016/j.gendis.2019.12.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/13/2019] [Accepted: 12/31/2019] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy is an X-linked recessive hereditary monogenic disorder caused by inability to produce dystrophin protein. In most patients, the expression of dystrophin lost due to disrupting mutations in open reading frame. Despite the efforts in a large number of different therapeutic approaches to date, the treatments available for DMD remain mitigative and supportive to improve the symptoms of the disease, rather than to be curative. The advent of CRISPR/Cas9 technology has revolutionized genome editing scope and considered as pioneer in effective genomic engineering. Deletions or excisions of intragenic DNA by CRISPR as well as a similar strategy with exon skipping at the DNA level induced by antisense oligonucleotides, are new and promising approaches in correcting DMD gene, which restore the expression of a truncated but functional dystrophin protein. Also, CRISPR/Cas9 technology can be used to treat DMD by removing duplicated exons, precise correction of causative mutation by HDR-based pathway and inducing the expression of compensatory proteins such as utrophin. In this study, we briefly explained the molecular genetics of DMD and a historical overview of DMD gene therapy. We in particular focused on CRISPR/Cas9-mediated therapeutic approaches that used to treat DMD.
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Affiliation(s)
- Hasan Mollanoori
- Department of Medical Genetics, Iran University of Medical Sciences (IUMS), Tehran, 1449614535, Iran
| | - Yazdan Rahmati
- Department of Medical Genetics, Iran University of Medical Sciences (IUMS), Tehran, 1449614535, Iran
| | - Bita Hassani
- Department of Medical Genetics, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, 1985717443, Iran
| | - Meysam Havasi Mehr
- Department of Physiology, Iran University of Medical Sciences (IUMS), Tehran, 1449614535, Iran
| | - Shahram Teimourian
- Department of Medical Genetics, Iran University of Medical Sciences (IUMS), Tehran, 1449614535, Iran
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20
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Abstract
Duchenne muscular dystrophy is a severe, progressive, muscle-wasting disease that leads to difficulties with movement and, eventually, to the need for assisted ventilation and premature death. The disease is caused by mutations in DMD (encoding dystrophin) that abolish the production of dystrophin in muscle. Muscles without dystrophin are more sensitive to damage, resulting in progressive loss of muscle tissue and function, in addition to cardiomyopathy. Recent studies have greatly deepened our understanding of the primary and secondary pathogenetic mechanisms. Guidelines for the multidisciplinary care for Duchenne muscular dystrophy that address obtaining a genetic diagnosis and managing the various aspects of the disease have been established. In addition, a number of therapies that aim to restore the missing dystrophin protein or address secondary pathology have received regulatory approval and many others are in clinical development.
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Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology and Department of Neurology, School of Medicine; Department of Biomedical Sciences, College of Veterinary Medicine; Department of Biomedical, Biological & Chemical Engineering, College of Engineering, University of Missouri, Columbia, MO, USA
| | - Nathalie Goemans
- Department of Child Neurology, University Hospitals Leuven, Leuven, Belgium
| | | | - Eugenio Mercuri
- Centro Clinico Nemo, Policlinico Gemelli, Rome, Italy
- Peadiatric Neurology, Catholic University, Rome, Italy
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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21
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Sheikh O, Yokota T. Developing DMD therapeutics: a review of the effectiveness of small molecules, stop-codon readthrough, dystrophin gene replacement, and exon-skipping therapies. Expert Opin Investig Drugs 2021; 30:167-176. [PMID: 33393390 DOI: 10.1080/13543784.2021.1868434] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder caused by mutations in the dystrophin (DMD) gene. Most patients die from respiratory failure or cardiomyopathy. There are significant unmet needs for treatments for DMD as the standard of care is principally limited to symptom relief through treatments including steroids. AREAS COVERED This review summarizes safety and efficacy in promising areas of DMD therapeutics - small molecules, stop codon readthrough, gene replacement, and exon skipping - under clinical examination from 2015-2020 as demonstrated in the NIH Clinical Trials and PubMed search engines. EXPERT OPINION Currently, steroids persist as the most accessible medicine for DMD. Stop-codon readthrough, gene replacement, and exon-skipping therapies all aim to restore dystrophin expression. Of these strategies, gene replacement therapy has recently gained momentum while exon-skipping retains great traction. The FDA approval of three exon-skipping antisense oligonucleotides illustrate this regulatory momentum, though the effectiveness and sequence design of eteplirsen remain controversial. Cell-penetrating peptides promise to more efficaciously treat DMD-related cardiomyopathy.The recent success of antisense therapies, however, poses major regulatory challenges. To fully realize the benefits of exon-skipping, including cocktail oligonucleotide-mediated multiple exon-skipping and oligonucleotide drugs for very rare mutations, regulatory challenges need to be addressed in coordination with scientific advances.
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Affiliation(s)
- Omar Sheikh
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta , Edmonton, Canada
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22
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Yavas A, Weij R, van Putten M, Kourkouta E, Beekman C, Puoliväli J, Bragge T, Ahtoniemi T, Knijnenburg J, Hoogenboom ME, Ariyurek Y, Aartsma-Rus A, van Deutekom J, Datson N. Detailed genetic and functional analysis of the hDMDdel52/mdx mouse model. PLoS One 2020; 15:e0244215. [PMID: 33362201 PMCID: PMC7757897 DOI: 10.1371/journal.pone.0244215] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/07/2020] [Indexed: 01/30/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe, progressive neuromuscular disorder caused by reading frame disrupting mutations in the DMD gene leading to absence of functional dystrophin. Antisense oligonucleotide (AON)-mediated exon skipping is a therapeutic approach aimed at restoring the reading frame at the pre-mRNA level, allowing the production of internally truncated partly functional dystrophin proteins. AONs work in a sequence specific manner, which warrants generating humanized mouse models for preclinical tests. To address this, we previously generated the hDMDdel52/mdx mouse model using transcription activator like effector nuclease (TALEN) technology. This model contains mutated murine and human DMD genes, and therefore lacks mouse and human dystrophin resulting in a dystrophic phenotype. It allows preclinical evaluation of AONs inducing the skipping of human DMD exons 51 and 53 and resulting in restoration of dystrophin synthesis. Here, we have further characterized this model genetically and functionally. We discovered that the hDMD and hDMDdel52 transgene is present twice per locus, in a tail-to-tail-orientation. Long-read sequencing revealed a partial deletion of exon 52 (first 25 bp), and a 2.3 kb inversion in intron 51 in both copies. These new findings on the genomic make-up of the hDMD and hDMDdel52 transgene do not affect exon 51 and/or 53 skipping, but do underline the need for extensive genetic analysis of mice generated with genome editing techniques to elucidate additional genetic changes that might have occurred. The hDMDdel52/mdx mice were also evaluated functionally using kinematic gait analysis. This revealed a clear and highly significant difference in overall gait between hDMDdel52/mdx mice and C57BL6/J controls. The motor deficit detected in the model confirms its suitability for preclinical testing of exon skipping AONs for human DMD at both the functional and molecular level.
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Affiliation(s)
- Alper Yavas
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Rudie Weij
- BioMarin Nederland BV, Leiden, The Netherlands
| | - Maaike van Putten
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | - Timo Bragge
- Charles River Discovery Services, Kuopio, Finland
| | | | - Jeroen Knijnenburg
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Yavuz Ariyurek
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
- * E-mail:
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23
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Solberg MH, Shariatzadeh M, Wilson SL. Gene modification strategies using AO‐mediated exon skipping and CRISPR/Cas9 as potential therapies for Duchenne muscular dystrophy patients. ENGINEERING BIOLOGY 2020; 4:37-42. [PMID: 36968157 PMCID: PMC9996716 DOI: 10.1049/enb.2020.0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked genetic disease affecting 1 in 5000 young males worldwide annually. Patients experience muscle weakness and loss of ambulation at an early age, with ∼75% reduced life expectancy. Recently developed genetic editing strategies aim to convert severe DMD phenotypes to a milder disease course. Among these, the antisense oligonucleotide (AO)-mediated exon skipping and the adeno-associated viral-delivered clustered regularly interspaced short palindromic repeat (CRISPR) associated protein 9 (adeno-associated viral (AAV)-delivered CRISPR/Cas9) gene editing have shown promising results in restoring dystrophin protein expression and functionality in skeletal and heart muscle in both animals and human cells in vivo and in vitro. However, therapeutic benefits currently remain unclear. The aim of this review is to compare the potential therapeutic benefits, efficacy, safety, and clinical progress of AO-mediated exon skipping and CRISPR/Cas9 gene-editing strategies. Both techniques have demonstrated therapeutic benefit and long-term efficacy in clinical trials. AAV-delivery of CRISPR/Cas9 may potentially correct disease-causing mutations following a single treatment compared to the required continuous AO/PMO-delivery of exon skipping drugs. The latter has the potential to increase the dystrophin expression in skeletal/heart muscle with sustained effects. However, therapeutic challenges including the need for optimised delivery must be overcome in to advance current clinical data.
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Affiliation(s)
- Marthe Helene Solberg
- National Centre for Sport and Exercise Medicine, School of Sport Exercise and Health Sciences Loughborough University Epinal Way, Loughborough Leicestershire LE11 3TU UK
| | - Maryam Shariatzadeh
- Centre for Biological Engineering, Wolfson School of Mechanical, Electrical and Manufacturing Engineering Loughborough University Epinal Way, Loughborough Leicestershire LE11 3TU UK
| | - Samantha L Wilson
- Centre for Biological Engineering, Wolfson School of Mechanical, Electrical and Manufacturing Engineering Loughborough University Epinal Way, Loughborough Leicestershire LE11 3TU UK
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24
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Sheikh O, Yokota T. Advances in Genetic Characterization and Genotype-Phenotype Correlation of Duchenne and Becker Muscular Dystrophy in the Personalized Medicine Era. J Pers Med 2020; 10:E111. [PMID: 32899151 PMCID: PMC7565713 DOI: 10.3390/jpm10030111] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/30/2020] [Accepted: 09/01/2020] [Indexed: 12/18/2022] Open
Abstract
Currently, Duchenne muscular dystrophy (DMD) and the related condition Becker muscular dystrophy (BMD) can be usually diagnosed using physical examination and genetic testing. While BMD features partially functional dystrophin protein due to in-frame mutations, DMD largely features no dystrophin production because of out-of-frame mutations. However, BMD can feature a range of phenotypes from mild to borderline DMD, indicating a complex genotype-phenotype relationship. Despite two mutational hot spots in dystrophin, mutations can arise across the gene. The use of multiplex ligation amplification (MLPA) can easily assess the copy number of all exons, while next-generation sequencing (NGS) can uncover novel or confirm hard-to-detect mutations. Exon-skipping therapy, which targets specific regions of the dystrophin gene based on a patient's mutation, is an especially prominent example of personalized medicine for DMD. To maximize the benefit of exon-skipping therapies, accurate genetic diagnosis and characterization including genotype-phenotype correlation studies are becoming increasingly important. In this article, we present the recent progress in the collection of mutational data and optimization of exon-skipping therapy for DMD/BMD.
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Affiliation(s)
- Omar Sheikh
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB T6G 2H7, Canada;
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB T6G 2H7, Canada;
- The Friends of Garrett Cumming Research & Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB T6G 2H7, Canada
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Sun C, Shen L, Zhang Z, Xie X. Therapeutic Strategies for Duchenne Muscular Dystrophy: An Update. Genes (Basel) 2020; 11:genes11080837. [PMID: 32717791 PMCID: PMC7463903 DOI: 10.3390/genes11080837] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/14/2020] [Accepted: 07/21/2020] [Indexed: 12/25/2022] Open
Abstract
Neuromuscular disorders encompass a heterogeneous group of conditions that impair the function of muscles, motor neurons, peripheral nerves, and neuromuscular junctions. Being the most common and most severe type of muscular dystrophy, Duchenne muscular dystrophy (DMD), is caused by mutations in the X-linked dystrophin gene. Loss of dystrophin protein leads to recurrent myofiber damage, chronic inflammation, progressive fibrosis, and dysfunction of muscle stem cells. Over the last few years, there has been considerable development of diagnosis and therapeutics for DMD, but current treatments do not cure the disease. Here, we review the current status of DMD pathogenesis and therapy, focusing on mutational spectrum, diagnosis tools, clinical trials, and therapeutic approaches including dystrophin restoration, gene therapy, and myogenic cell transplantation. Furthermore, we present the clinical potential of advanced strategies combining gene editing, cell-based therapy with tissue engineering for the treatment of muscular dystrophy.
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Affiliation(s)
- Chengmei Sun
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Zhejiang University, Haining 314400, China; (C.S.); (L.S.); (Z.Z.)
- Department of Medical Oncology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310009, China
| | - Luoan Shen
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Zhejiang University, Haining 314400, China; (C.S.); (L.S.); (Z.Z.)
| | - Zheng Zhang
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Zhejiang University, Haining 314400, China; (C.S.); (L.S.); (Z.Z.)
| | - Xin Xie
- Zhejiang University-University of Edinburgh Institute, School of Medicine, Zhejiang University, Haining 314400, China; (C.S.); (L.S.); (Z.Z.)
- Department of Medical Oncology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Zhejiang University, Hangzhou 310009, China
- Correspondence: ; Tel.: +86-0571-87572326
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26
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Nguyen Q, Lim KRQ, Yokota T. Genome Editing for the Understanding and Treatment of Inherited Cardiomyopathies. Int J Mol Sci 2020; 21:E733. [PMID: 31979133 PMCID: PMC7036815 DOI: 10.3390/ijms21030733] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 01/16/2020] [Accepted: 01/19/2020] [Indexed: 02/08/2023] Open
Abstract
Cardiomyopathies are diseases of heart muscle, a significant percentage of which are genetic in origin. Cardiomyopathies can be classified as dilated, hypertrophic, restrictive, arrhythmogenic right ventricular or left ventricular non-compaction, although mixed morphologies are possible. A subset of neuromuscular disorders, notably Duchenne and Becker muscular dystrophies, are also characterized by cardiomyopathy aside from skeletal myopathy. The global burden of cardiomyopathies is certainly high, necessitating further research and novel therapies. Genome editing tools, which include zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR) systems have emerged as increasingly important technologies in studying this group of cardiovascular disorders. In this review, we discuss the applications of genome editing in the understanding and treatment of cardiomyopathy. We also describe recent advances in genome editing that may help improve these applications, and some future prospects for genome editing in cardiomyopathy treatment.
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Affiliation(s)
- Quynh Nguyen
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (Q.N.); (K.R.Q.L.)
| | - Kenji Rowel Q. Lim
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (Q.N.); (K.R.Q.L.)
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (Q.N.); (K.R.Q.L.)
- The Friends of Garrett Cumming Research & Muscular Dystrophy Canada, HM Toupin Neurological Science Research Chair, Edmonton, AB T6G2H7, Canada
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Gibbs EM, Barthélémy F, Douine ED, Hardiman NC, Shieh PB, Khanlou N, Crosbie RH, Nelson SF, Miceli MC. Large in-frame 5' deletions in DMD associated with mild Duchenne muscular dystrophy: Two case reports and a review of the literature. Neuromuscul Disord 2019; 29:863-873. [PMID: 31672265 PMCID: PMC7092699 DOI: 10.1016/j.nmd.2019.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 08/28/2019] [Accepted: 09/10/2019] [Indexed: 10/26/2022]
Abstract
Duchenne muscular dystrophy is caused by mutations in the dystrophin-encoding DMD gene. While Duchenne is most commonly caused by large intragenic deletions that cause frameshift and complete loss of dystrophin expression, in-frame deletions in DMD can result in the expression of internally truncated dystrophin proteins and may be associated with a milder phenotype. In this study, we describe two individuals with large in-frame 5' deletions (exon 3-23 and exon 3-28) that remove the majority of the N-terminal region, including part of the actin binding and central rod domains. Both patients had progressive muscle weakness during childhood but are observed to have a relatively mild disease course compared to typical Duchenne. We show that in muscle biopsies from both patients, truncated dystrophin is expressed at the sarcolemma. We have additionally developed a patient-specific fibroblast-derived cell model, which can be inducibly reprogrammed to form myotubes that largely recapitulate biopsy findings for the patient with the exon 3-23 deletion, providing a culture model for future investigation of this unusual case. We discuss these mutations in the context of previously reported 5' in-frame DMD deletions and relevant animal models, and review the spectrum of phenotypes associated with these deletions.
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Affiliation(s)
- Elizabeth M Gibbs
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA; Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA
| | - Florian Barthélémy
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Emilie D Douine
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Natalie C Hardiman
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Perry B Shieh
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 90095, USA
| | - Negar Khanlou
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Rachelle H Crosbie
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095, USA; Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 90095, USA; Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | - Stanley F Nelson
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, 90095, USA
| | - M Carrie Miceli
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA 90095, USA; Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.
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Wells DJ. What is the level of dystrophin expression required for effective therapy of Duchenne muscular dystrophy? J Muscle Res Cell Motil 2019; 40:141-150. [PMID: 31289969 DOI: 10.1007/s10974-019-09535-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/27/2019] [Indexed: 12/21/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a fatal X-linked muscle wasting disease. The disease is due to mutations in the DMD gene that encodes for a large intracellular protein called dystrophin. Dystrophin plays a critical role in linking the internal cytoskeleton of the striated muscle cell with the extracellular matrix as well as having cell signalling functions. In its absence muscle contraction is associated with cycles of damage, repair, inflammation and fibrosis with eventual loss of muscle and replacement with fat. Experiments in animal models of DMD have generated a number of different approaches to the induction of dystrophin including viral vector mediated delivery of a recombinant dystrophin gene, antisense oligonucleotide mediated exon-skipping to restore the open reading frame in the dystrophin mRNA, read-through of premature stop mutations, genome modification using CRISPR-Cas9 or cell based transfer of a functional dystrophin gene. In all cases, it will be important to understand how much dystrophin expression is required for a clinically effective therapy and this review examines the data from humans and animal models to estimate the percentage of endogenous dystrophin that is likely to have significant clinical benefit. While there are a number of important caveats to consider, including the appropriate outcome measures, this review suggests that approximately 20% of endogenous levels uniformly distributed within the skeletal muscles and the heart may be sufficient to largely prevent disease progression.
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Affiliation(s)
- Dominic J Wells
- Neuromuscular Diseases Group, Department of Comparative Biomedical Sciences, Royal Veterinary College, Royal College Street, London, NW1 0TU, UK.
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29
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Tsoumpra MK, Fukumoto S, Matsumoto T, Takeda S, Wood MJA, Aoki Y. Peptide-conjugate antisense based splice-correction for Duchenne muscular dystrophy and other neuromuscular diseases. EBioMedicine 2019; 45:630-645. [PMID: 31257147 PMCID: PMC6642283 DOI: 10.1016/j.ebiom.2019.06.036] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/31/2019] [Accepted: 06/18/2019] [Indexed: 12/14/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked disorder characterized by progressive muscle degeneration, caused by the absence of dystrophin. Exon skipping by antisense oligonucleotides (ASOs) has recently gained recognition as therapeutic approach in DMD. Conjugation of a peptide to the phosphorodiamidate morpholino backbone (PMO) of ASOs generated the peptide-conjugated PMOs (PPMOs) that exhibit a dramatically improved pharmacokinetic profile. When tested in animal models, PPMOs demonstrate effective exon skipping in target muscles and prolonged duration of dystrophin restoration after a treatment regime. Herein we summarize the main pathophysiological features of DMD and the emergence of PPMOs as promising exon skipping agents aiming to rescue defective gene expression in DMD and other neuromuscular diseases. The listed PPMO laboratory findings correspond to latest trends in the field and highlight the obstacles that must be overcome prior to translating the animal-based research into clinical trials tailored to the needs of patients suffering from neuromuscular diseases.
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Key Words
- aso, antisense oligonucleotides
- cns, central nervous system
- cpp, cell penetrating peptide
- dgc, dystrophin glyco-protein complex
- dmd, duchenne muscular dystrophy
- fda, us food and drug administration
- pmo, phosphorodiamidate morpholino
- ppmo, peptide-conjugated pmos
- ps, phosphorothioate
- sma, spinal muscular atrophy
- 2ʹ-ome, 2ʹ-o-methyl
- 2ʹ-moe, 2ʹ-o-methoxyethyl
- 6mwt, 6-minute walk test
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Affiliation(s)
- Maria K Tsoumpra
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Toshio Matsumoto
- Fujii Memorial Institute of Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan
| | | | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan.
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Egorova TV, Zotova ED, Reshetov DA, Polikarpova AV, Vassilieva SG, Vlodavets DV, Gavrilov AA, Ulianov SV, Buchman VL, Deykin AV. CRISPR/Cas9-generated mouse model of Duchenne muscular dystrophy recapitulating a newly identified large 430 kb deletion in the human DMD gene. Dis Model Mech 2019; 12:dmm037655. [PMID: 31028078 PMCID: PMC6505476 DOI: 10.1242/dmm.037655] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/20/2019] [Indexed: 01/10/2023] Open
Abstract
Exon skipping is a promising strategy for Duchenne muscular dystrophy (DMD) disease-modifying therapy. To make this approach safe, ensuring that excluding one or more exons will restore the reading frame and that the resulting protein will retain critical functions of the full-length dystrophin protein is necessary. However, in vivo testing of the consequences of skipping exons that encode the N-terminal actin-binding domain (ABD) has been confounded by the absence of a relevant animal model. We created a mouse model of the disease recapitulating a novel human mutation, a large de novo deletion of exons 8-34 of the DMD gene, found in a Russian DMD patient. This mutation was achieved by deleting exons 8-34 of the X-linked mouse D md gene using CRISPR/Cas9 genome editing, which led to a reading frame shift and the absence of functional dystrophin production. Male mice carrying this deletion display several important signs of muscular dystrophy, including a gradual age-dependent decrease in muscle strength, increased creatine kinase, muscle fibrosis and central nucleation. The degrees of these changes are comparable to those observed in mdx mice, a standard laboratory model of DMD. This new model of DMD will be useful for validating therapies based on skipping exons that encode the N-terminal ABD and for improving our understanding of the role of the N-terminal domain and central rod domain in the biological function of dystrophin. Simultaneous skipping of exons 6 and 7 should restore the gene reading frame and lead to the production of a protein that might retain functionality despite the partial deletion of the ABD.
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Affiliation(s)
- Tatiana V Egorova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
- Marlin Biotech LLC, Moscow, 143026, Russia
| | | | | | - Anna V Polikarpova
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
- Marlin Biotech LLC, Moscow, 143026, Russia
| | - Svetlana G Vassilieva
- Laboratory of Modeling and Gene Therapy of Hereditary Diseases, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
- Marlin Biotech LLC, Moscow, 143026, Russia
| | - Dmitry V Vlodavets
- Veltischev Scientific Research Clinical Paediatric Institute, Moscow, 125412, Russia
| | - Alexey A Gavrilov
- Group of Genome Spatial Organization, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Sergey V Ulianov
- Laboratory of Structural and Functional Organization of Chromosomes, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, 119991, Russia
| | | | - Alexei V Deykin
- Core Facilities, Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
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Maruyama R, Aoki Y, Takeda S, Yokota T. In Vivo Evaluation of Multiple Exon Skipping with Peptide-PMOs in Cardiac and Skeletal Muscles in Dystrophic Dogs. Methods Mol Biol 2019; 1828:365-379. [PMID: 30171554 DOI: 10.1007/978-1-4939-8651-4_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Exon skipping is an emerging approach to treating Duchenne muscular dystrophy (DMD), one of the most common lethal genetic disorders. Exon skipping uses synthetic antisense oligonucleotides (AONs) to splice out frame-disrupting exon(s) of DMD mRNA to restore the reading frame of the gene products and produce truncated yet functional proteins. The FDA conditionally approved the first exon-skipping AON, called eteplirsen (brand name ExonDys51), targeting exon 51 of the DMD gene, in late 2016. Using a cocktail of AONs, multiple exons can be skipped, which can theoretically treat 80-90% of patients with DMD. Although the success of multiple exon skipping in a DMD dog model has made a significant impact on the development of therapeutics for DMD, unmodified AONs such as phosphorodiamidate morpholino oligomers (PMOs) have little efficacy in cardiac muscles. Here, we describe our technique of intravenous injection of a cocktail of peptide-conjugated PMOs (PPMOs) to skip multiple exons, exons 6 and 8, in both skeletal and cardiac muscles in dystrophic dogs and the evaluation of the efficacy and toxicity.
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Affiliation(s)
- Rika Maruyama
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada
| | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Japan.
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada. .,The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Endowed Research Chair, Edmonton, AB, Canada.
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Tips to Design Effective Splice-Switching Antisense Oligonucleotides for Exon Skipping and Exon Inclusion. Methods Mol Biol 2019; 1828:79-90. [PMID: 30171536 DOI: 10.1007/978-1-4939-8651-4_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Antisense-mediated exon skipping and exon inclusion have proven to be powerful tools for treating neuromuscular diseases. The approval of Exondys 51 (eteplirsen) and Spinraza (nusinersen) for the treatment of patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) was the most noteworthy accomplishment in 2016. Exon skipping uses short DNA-like molecules called antisense oligonucleotides (AONs) to correct the disrupted reading frame, allowing the production of functional quasi-dystrophin proteins, and ameliorate the progression of the disease. Exon inclusion for SMA employs an AON targeting an intronic splice silencer site to include an exon which is otherwise spliced out. Recently, these strategies have also been explored in many other genetic disorders, including dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy; MM, limb-girdle muscular dystrophy type 2B; LGMD2B, and distal myopathy with anterior tibial onset; DMAT), laminin α2 chain (merosin)-deficient congenital muscular dystrophy (MDC1A), sarcoglycanopathy (e.g., limb-girdle muscular dystrophy type 2C; LGMD2C), and Fukuyama congenital muscular dystrophy (FCMD). A major challenge in exon skipping and exon inclusion is the difficulty in designing effective AONs. The mechanism of mRNA splicing is highly complex, and the efficacy of AONs is often unpredictable. We will discuss the design of effective AONs for exon skipping and exon inclusion in this chapter.
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Nakamura A. Mutation-Based Therapeutic Strategies for Duchenne Muscular Dystrophy: From Genetic Diagnosis to Therapy. J Pers Med 2019; 9:jpm9010016. [PMID: 30836656 PMCID: PMC6462977 DOI: 10.3390/jpm9010016] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/22/2019] [Accepted: 02/22/2019] [Indexed: 02/06/2023] Open
Abstract
Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked muscle disorders caused by mutations of the DMD gene, which encodes the subsarcolemmal protein dystrophin. In DMD, dystrophin is not expressed due to a disruption in the reading frame of the DMD gene, resulting in a severe phenotype. Becker muscular dystrophy exhibits a milder phenotype, having mutations that maintain the reading frame and allow for the production of truncated dystrophin. To date, various therapeutic approaches for DMD have been extensively developed. However, the pathomechanism is quite complex despite it being a single gene disorder, and dystrophin is expressed not only in a large amount of skeletal muscle but also in cardiac, vascular, intestinal smooth muscle, and nervous system tissue. Thus, the most appropriate therapy would be complementation or restoration of dystrophin expression, such as gene therapy using viral vectors, readthrough therapy, or exon skipping therapy. Among them, exon skipping therapy with antisense oligonucleotides can restore the reading frame and yield the conversion of a severe phenotype to one that is mild. In this paper, I present the significance of molecular diagnosis and the development of mutation-based therapeutic strategies to complement or restore dystrophin expression.
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Affiliation(s)
- Akinori Nakamura
- Department of Neurology, National Hospital Organization, Matsumoto Medical Center, 2-20-30 Murai-machi Minami, Matsumoto 399-8701, Japan.
- Third Department of Medicine, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
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34
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Multiple Exon Skipping in the Duchenne Muscular Dystrophy Hot Spots: Prospects and Challenges. J Pers Med 2018; 8:jpm8040041. [PMID: 30544634 PMCID: PMC6313462 DOI: 10.3390/jpm8040041] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/24/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), a fatal X-linked recessive disorder, is caused mostly by frame-disrupting, out-of-frame deletions in the dystrophin (DMD) gene. Antisense oligonucleotide-mediated exon skipping is a promising therapy for DMD. Exon skipping aims to convert out-of-frame mRNA to in-frame mRNA and induce the production of internally-deleted dystrophin as seen in the less severe Becker muscular dystrophy. Currently, multiple exon skipping has gained special interest as a new therapeutic modality for this approach. Previous retrospective database studies represented a potential therapeutic application of multiple exon skipping. Since then, public DMD databases have become more useful with an increase in patient registration and advances in molecular diagnosis. Here, we provide an update on DMD genotype-phenotype associations using a global DMD database and further provide the rationale for multiple exon skipping development, particularly for exons 45–55 skipping and an emerging therapeutic concept, exons 3–9 skipping. Importantly, this review highlights the potential of multiple exon skipping for enabling the production of functionally-corrected dystrophin and for treating symptomatic patients not only with out-of-frame deletions but also those with in-frame deletions. We will also discuss prospects and challenges in multiple exon skipping therapy, referring to recent progress in antisense chemistry and design, as well as disease models.
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35
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Roovers J, De Jonghe P, Weckhuysen S. The therapeutic potential of RNA regulation in neurological disorders. Expert Opin Ther Targets 2018; 22:1017-1028. [PMID: 30372655 DOI: 10.1080/14728222.2018.1542429] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Gene regulation is the term used to describe the mechanisms by which a cell increases or decreases the amount of a gene product (RNA or protein). In complex organs such as the brain, gene regulation is of the utmost importance; aberrations in the regulation of specific genes can lead to neurological disorders. Understanding these mechanisms can create new strategies for targeting these disorders and progress is being made. Two drugs that function at the RNA level (nusinersen and eteplirsen) have now been approved by the FDA for the treatment of Spinomuscular atrophy and Duchenne muscular dystrophy, respectively; several other compounds for neurological disease are currently being investigated in preclinical studies and clinical trials. Areas covered: We highlight how gene regulation at the level of RNA molecules can be used as a therapeutic strategy to treat neurological disorders. We provide examples of how such an approach is being studied or used and discuss the current hurdles. Expert opinion: Targeting gene expression at the RNA level is a promising strategy to treat genetic neurological disorders. Safe administration, long-term efficacy, and potential side effects, however, still need careful evaluation before RNA therapeutics can be applied on a larger scale.
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Affiliation(s)
- Jolien Roovers
- a Neurogenetics Group , Center for Molecular Neurology, VIB , Antwerp , Belgium.,b Laboratory of Neurogenetics, Institute Born-Bunge , University of Antwerp , Antwerp , Belgium
| | - Peter De Jonghe
- a Neurogenetics Group , Center for Molecular Neurology, VIB , Antwerp , Belgium.,b Laboratory of Neurogenetics, Institute Born-Bunge , University of Antwerp , Antwerp , Belgium.,c Department of Neurology , University Hospital Antwerp , Antwerp , Belgium
| | - Sarah Weckhuysen
- a Neurogenetics Group , Center for Molecular Neurology, VIB , Antwerp , Belgium.,b Laboratory of Neurogenetics, Institute Born-Bunge , University of Antwerp , Antwerp , Belgium.,c Department of Neurology , University Hospital Antwerp , Antwerp , Belgium
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36
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Yuan R, Yi J, Xie Z, Zheng Y, Han M, Hou Y, Wang Z, Yuan Y. Genotype-phenotype correlation in Becker muscular dystrophy in Chinese patients. J Hum Genet 2018; 63:1041-1048. [PMID: 29976999 DOI: 10.1038/s10038-018-0480-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/23/2018] [Accepted: 06/01/2018] [Indexed: 12/26/2022]
Abstract
Large deletions and duplications are the most frequent causative mutations in Becker muscular dystrophy (BMD), but genetic profile varied greatly among reports. We performed a comprehensive molecular investigation in 95 Chinese BMD patients. All patients were divided into three subtypes: normal muscle strength (type 1) in 18 cases, quadriceps myopathy (type 2) in 20 cases, and limb-girdle weakness (type 3) in 57 cases. Nineteen cases (20.0%) had small mutations and 76 cases (80.0%) had major rearrangements, including 67 cases (70.5%) of exonic deletions and 9 cases (9.5%) of exonic duplications. We identified 50 cases (65.8%) of in-frame mutations, and 26 cases (34.2%) of frame-shift mutations. The frequency of deletion in exons 13-19 was 30.6% in type 1 patients, 9.7% in type 2 patients, and 10.4% in type 3 patients. The frequency of deletion in exons 45-55 was 28.6% in type 1 patients, 40.8% in type 2, and 50.0% in type 3 patients. All major rearrangements of DMD gene in type 1 patients were also observed in type 3 patients. Our study suggested that frame-shift mutation was not rare in Chinese BMD patients. Although no difference was observed on the forms of DMD gene mutations among the three types of patients, the mutation in proximal region of DMD gene has higher frequency for patients without weakness. Effect of exon skipping for DMD depends on the size and location of the mutation. Additional studies are required to determine whether exon-skipping strategies in proximal region of DMD gene could yield more functional dystrophin.
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Affiliation(s)
- Ruiyi Yuan
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China.,Haverford Collage, Haverford, PA, 19041, USA
| | - Junfei Yi
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China
| | - Zhiying Xie
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China
| | - Yimeng Zheng
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China
| | - Miao Han
- Department of Neurology, First Hospital, Henan University, Kaifeng Shi, China
| | - Yue Hou
- Department of Neurology, Traditional Medicine Hospital, Guangzhou University, Guangzhou, China
| | - Zhaoxia Wang
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China
| | - Yun Yuan
- Department of Neurology, First Hospital, Peking University, 100034, Beijing, China.
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37
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Abstract
During the past 10 years, antisense oligonucleotide-mediated exon skipping and splice modulation have proven to be powerful tools for correction of mRNA splicing in genetic diseases. In 2016, the US Food and Drug Administration (FDA)-approved Exondys 51 (eteplirsen) and Spinraza (nusinersen), the first exon skipping and exon inclusion drugs, to treat patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), respectively. The exon skipping of DMD mRNA aims to restore the disrupted reading frame using antisense oligonucleotides (AONs), allowing the production of truncated but partly functional dystrophin proteins, and slow down the progression of the disease. This approach has also been explored in several other genetic disorders, including laminin α2 chain-deficient congenital muscular dystrophy, dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy and limb-girdle muscular dystrophy type 2B), sarcoglycanopathy (limb-girdle muscular dystrophy type 2C), and Fukuyama congenital muscular dystrophy. Antisense-mediated exon skipping is also a powerful tool to examine the function of genes and exons. A significant challenge in exon skipping is how to design effective AONs. The mechanism of mRNA splicing is highly complex with many factors involved. The selection of target sites, the length of AONs, the AON chemistry, and the melting temperature versus the RNA strand play important roles. A cocktail of AONs can be employed to skip multiples exons. In this chapter, we discuss the design of effective AONs for exon skipping.
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Aslesh T, Maruyama R, Yokota T. Skipping Multiple Exons to Treat DMD-Promises and Challenges. Biomedicines 2018; 6:E1. [PMID: 29301272 PMCID: PMC5874658 DOI: 10.3390/biomedicines6010001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/19/2017] [Accepted: 12/19/2017] [Indexed: 01/08/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal disorder caused by mutations in the DMD gene. Antisense-mediated exon-skipping is a promising therapeutic strategy that makes use of synthetic nucleic acids to skip frame-disrupting exon(s) and allows for short but functional protein expression by restoring the reading frame. In 2016, the U.S. Food and Drug Administration (FDA) approved eteplirsen, which skips DMD exon 51 and is applicable to approximately 13% of DMD patients. Multiple exon skipping, which is theoretically applicable to 80-90% of DMD patients in total, have been demonstrated in animal models, including dystrophic mice and dogs, using cocktail antisense oligonucleotides (AOs). Although promising, current drug approval systems pose challenges for the use of a cocktail AO. For example, both exons 6 and 8 need to be skipped to restore the reading frame in dystrophic dogs. Therefore, the cocktail of AOs targeting these exons has a combined therapeutic effect and each AO does not have a therapeutic effect by itself. The current drug approval system is not designed to evaluate such circumstances, which are completely different from cocktail drug approaches in other fields. Significant changes are needed in the drug approval process to promote the cocktail AO approach.
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Affiliation(s)
- Tejal Aslesh
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8812-112 St. Edmonton, AB T6G 2H7, Canada.
| | - Rika Maruyama
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8812-112 St. Edmonton, AB T6G 2H7, Canada.
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, 8812-112 St. Edmonton, AB T6G 2H7, Canada.
- The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, 8812-112 St. Edmonton, AB T6G 2H7, Canada.
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39
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Maruyama R, Yokota T. Creation of DMD Muscle Cell Model Using CRISPR-Cas9 Genome Editing to Test the Efficacy of Antisense-Mediated Exon Skipping. Methods Mol Biol 2018; 1828:165-171. [PMID: 30171541 DOI: 10.1007/978-1-4939-8651-4_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating muscle disorder caused by mutations in the DMD gene. Antisense-mediated exon skipping is a promising strategy to treat DMD. The approval of Exondys 51 (eteplirsen) targeting exon 51 was the most noteworthy accomplishment in 2016. To evaluate and optimize the sequence of antisense oligonucleotides (AOs), muscle cell lines with DMD mutations are useful tools. However, there are only several immortalized muscle cell lines with DMD mutations available that can be used to test the efficacy of exon skipping in vitro. In addition, an invasive muscle biopsy is required to obtain muscle cells from patients. Furthermore, many DMD mutations are very rare and it is hard to find a patient with a specific mutation for muscle biopsy in many cases. Here, we describe a novel approach to create an immortalized muscle cell line with a DMD deletion mutation using the human rhabdomyosarcoma (RD) cell line and the CRISPR/Cas9 system that can be used to test the efficacy of exon skipping.
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Affiliation(s)
- Rika Maruyama
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada.
- The Friends of Garrett Cumming Research & Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada.
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40
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An Overview of Recent Advances and Clinical Applications of Exon Skipping and Splice Modulation for Muscular Dystrophy and Various Genetic Diseases. Methods Mol Biol 2018; 1828:31-55. [PMID: 30171533 DOI: 10.1007/978-1-4939-8651-4_2] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Exon skipping is a therapeutic approach that is feasible for various genetic diseases and has been studied and developed for over two decades. This approach uses antisense oligonucleotides (AON) to modify the splicing of pre-mRNA to correct the mutation responsible for a disease, or to suppress a particular gene expression, as in allergic diseases. Antisense-mediated exon skipping is most extensively studied in Duchenne muscular dystrophy (DMD) and has developed from in vitro proof-of-concept studies to clinical trials targeting various single exons such as exon 45 (casimersen), exon 53 (NS-065/NCNP-01, golodirsen), and exon 51 (eteplirsen). Eteplirsen (brand name Exondys 51), is the first approved antisense therapy for DMD in the USA, and provides a treatment option for ~14% of all DMD patients, who are amenable to exon 51 skipping. Eteplirsen is granted accelerated approval and marketing authorization by the US Food and Drug Administration (FDA), on the condition that additional postapproval trials show clinical benefit. Permanent exon skipping achieved at the DNA level using clustered regularly interspaced short palindromic repeats (CRISPR) technology holds promise in current preclinical trials for DMD. In hopes of achieving clinical success parallel to DMD, exon skipping and splice modulation are also being studied in other muscular dystrophies, such as Fukuyama congenital muscular dystrophy (FCMD), dysferlinopathy including limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy (MM), and distal anterior compartment myopathy (DMAT), myotonic dystrophy, and merosin-deficient congenital muscular dystrophy type 1A (MDC1A). This chapter also summarizes the development of antisense-mediated exon skipping therapy in diseases such as Usher syndrome, dystrophic epidermolysis bullosa, fibrodysplasia ossificans progressiva (FOP), and allergic diseases.
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41
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Kyrychenko V, Kyrychenko S, Tiburcy M, Shelton JM, Long C, Schneider JW, Zimmermann WH, Bassel-Duby R, Olson EN. Functional correction of dystrophin actin binding domain mutations by genome editing. JCI Insight 2017; 2:95918. [PMID: 28931764 DOI: 10.1172/jci.insight.95918] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 08/15/2017] [Indexed: 12/26/2022] Open
Abstract
Dystrophin maintains the integrity of striated muscles by linking the actin cytoskeleton with the cell membrane. Duchenne muscular dystrophy (DMD) is caused by mutations in the dystrophin gene (DMD) that result in progressive, debilitating muscle weakness, cardiomyopathy, and a shortened lifespan. Mutations of dystrophin that disrupt the amino-terminal actin-binding domain 1 (ABD-1), encoded by exons 2-8, represent the second-most common cause of DMD. In the present study, we compared three different strategies for CRISPR/Cas9 genome editing to correct mutations in the ABD-1 region of the DMD gene by deleting exons 3-9, 6-9, or 7-11 in human induced pluripotent stem cells (iPSCs) and by assessing the function of iPSC-derived cardiomyocytes. All three exon deletion strategies enabled the expression of truncated dystrophin protein and restoration of cardiomyocyte contractility and calcium transients to varying degrees. We show that deletion of exons 3-9 by genomic editing provides an especially effective means of correcting disease-causing ABD-1 mutations. These findings represent an important step toward eventual correction of common DMD mutations and provide a means of rapidly assessing the expression and function of internally truncated forms of dystrophin-lacking portions of ABD-1.
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Affiliation(s)
- Viktoriia Kyrychenko
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sergii Kyrychenko
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Malte Tiburcy
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - John M Shelton
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chengzu Long
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jay W Schneider
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Wolfram-Hubertus Zimmermann
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Göttingen, Germany
| | - Rhonda Bassel-Duby
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Eric N Olson
- Department of Molecular Biology.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, and.,Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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42
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Moving towards successful exon-skipping therapy for Duchenne muscular dystrophy. J Hum Genet 2017; 62:871-876. [DOI: 10.1038/jhg.2017.57] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/28/2017] [Accepted: 05/01/2017] [Indexed: 01/15/2023]
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43
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Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 2017; 114:4213-4218. [PMID: 28373570 DOI: 10.1073/pnas.1613203114] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising therapeutic options, yet PMOs have shown very little efficacy in cardiac muscle. To increase therapeutic potency in cardiac muscle, we tested a next-generation morpholino: arginine-rich, cell-penetrating peptide-conjugated PMOs (PPMOs) in the canine X-linked muscular dystrophy in Japan (CXMDJ) dog model of DMD. A PPMO cocktail designed to skip dystrophin exons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMDJ dogs. Intravenous injections with PPMOs restored dystrophin expression in the myocardium and cardiac Purkinje fibers, as well as skeletal muscles. Vacuole degeneration of cardiac Purkinje fibers, as seen in DMD patients, was ameliorated in PPMO-treated dogs. Although symptoms and functions in skeletal muscle were not ameliorated by i.v. treatment, electrocardiogram abnormalities (increased Q-amplitude and Q/R ratio) were improved in CXMDJ dogs after intracoronary or i.v. administration. No obvious evidence of toxicity was found in blood tests throughout the monitoring period of one or four systemic treatments with the PPMO cocktail (12 mg/kg/injection). The present study reports the rescue of dystrophin expression and recovery of the conduction system in the heart of dystrophic dogs by PPMO-mediated multiexon skipping. We demonstrate that rescued dystrophin expression in the Purkinje fibers leads to the improvement/prevention of cardiac conduction abnormalities in the dystrophic heart.
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