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Auger M, Sorroza-Martinez L, Brahiti N, Huppé CA, Faucher-Giguère L, Arbi I, Hervault M, Cheng X, Gaillet B, Couture F, Guay D, Soultan AH. Enhancing peptide and PMO delivery to mouse airway epithelia by chemical conjugation with the amphiphilic peptide S10. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102290. [PMID: 39233851 PMCID: PMC11372590 DOI: 10.1016/j.omtn.2024.102290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 07/26/2024] [Indexed: 09/06/2024]
Abstract
Delivery of antisense oligonucleotides (ASOs) to airway epithelial cells is arduous due to the physiological barriers that protect the lungs and the endosomal entrapment phenomenon, which prevents ASOs from reaching their intracellular targets. Various delivery strategies involving peptide-, lipid-, and polymer-based carriers are being investigated, yet the challenge remains. S10 is a peptide-based delivery agent that enables the intracellular delivery of biomolecules such as GFP, CRISPR-associated nuclease ribonucleoprotein (RNP), base editor RNP, and a fluorescent peptide into lung cells after intranasal or intratracheal administrations to mice, ferrets, and rhesus monkeys. Herein, we demonstrate that covalently attaching S10 to a fluorescently labeled peptide or a functional splice-switching phosphorodiamidate morpholino oligomer improves their intracellular delivery to airway epithelia in mice after a single intranasal instillation. Data reveal a homogeneous delivery from the trachea to the distal region of the lungs, specifically into the cells lining the airway. Quantitative measurements further highlight that conjugation via a disulfide bond through a pegylated (PEG) linker was the most beneficial strategy compared with direct conjugation (without the PEG linker) or conjugation via a permanent thiol-maleimide bond. We believe that S10-based conjugation provides a great strategy to achieve intracellular delivery of peptides and ASOs with therapeutic properties in lungs.
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Affiliation(s)
- Maud Auger
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
- Département de génie chimique, Faculté des Sciences et de Génie, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine, Bureau 3550, Québec, QC G1V 0A6, Canada
| | - Luis Sorroza-Martinez
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
- Département de génie chimique, Faculté des Sciences et de Génie, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine, Bureau 3550, Québec, QC G1V 0A6, Canada
| | - Nadine Brahiti
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
| | - Carole-Ann Huppé
- Centre Collégial de Transfert de Technologie en Biotechnologies TransBIOTech, 201 Rue Monseigneur-Bourget, Lévis, QC G6V 6Z3, Canada
| | | | - Imen Arbi
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
| | - Maxime Hervault
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
| | - Xue Cheng
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
| | - Bruno Gaillet
- Département de génie chimique, Faculté des Sciences et de Génie, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine, Bureau 3550, Québec, QC G1V 0A6, Canada
| | - Frédéric Couture
- Centre Collégial de Transfert de Technologie en Biotechnologies TransBIOTech, 201 Rue Monseigneur-Bourget, Lévis, QC G6V 6Z3, Canada
| | - David Guay
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
- Département de génie chimique, Faculté des Sciences et de Génie, Université Laval, Pavillon Adrien-Pouliot 1065, av. de la Médecine, Bureau 3550, Québec, QC G1V 0A6, Canada
| | - Al-Halifa Soultan
- Feldan Therapeutics, 2666 Boulevard du Parc Technologique Suite 290, Québec, QC G1P 4S6, Canada
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2
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Gushchina LV, Bradley AJ, Vetter TA, Lay JW, Rohan NL, Frair EC, Wein N, Flanigan KM. Persistence of exon 2 skipping and dystrophin expression at 18 months after U7snRNA-mediated therapy in the Dup2 mouse model. Mol Ther Methods Clin Dev 2023; 31:101144. [PMID: 38027058 PMCID: PMC10679948 DOI: 10.1016/j.omtm.2023.101144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a progressive X-linked disease caused by mutations in the DMD gene that prevent the expression of a functional dystrophin protein. Exon duplications represent 6%-11% of mutations, and duplications of exon 2 (Dup2) are the most common (∼11%) of duplication mutations. An exon-skipping strategy for Dup2 mutations presents a large therapeutic window. Skipping one exon copy results in full-length dystrophin expression, whereas skipping of both copies (Del2) activates an internal ribosomal entry site (IRES) in exon 5, inducing the expression of a highly functional truncated dystrophin isoform. We have previously confirmed the therapeutic efficacy of AAV9.U7snRNA-mediated skipping in the Dup2 mouse model and showed the absence of off-target splicing effects and lack of toxicity in mice and nonhuman primates. Here, we report long-term dystrophin expression data following the treatment of 3-month-old Dup2 mice with the scAAV9.U7.ACCA vector. Significant exon 2 skipping and robust dystrophin expression in the muscles and hearts of treated mice persist at 18 months after treatment, along with the partial rescue of muscle function. These data extend our previous findings and show that scAAV9.U7.ACCA provides long-term protection by restoring the disrupted dystrophin reading frame in the context of exon 2 duplications.
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Affiliation(s)
- Liubov V. Gushchina
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Adrienne J. Bradley
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
| | - Tatyana A. Vetter
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Jacob W. Lay
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
| | - Natalie L. Rohan
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
| | - Emma C. Frair
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
| | - Nicolas Wein
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Kevin M. Flanigan
- The Center for Gene Therapy, Nationwide Children’s Hospital and The Ohio State University, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
- Department of Neurology, The Ohio State University, Columbus, OH, USA
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3
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Mashima R, Takada S, Miyamoto Y. RNA-Based Therapeutic Technology. Int J Mol Sci 2023; 24:15230. [PMID: 37894911 PMCID: PMC10607345 DOI: 10.3390/ijms242015230] [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: 09/11/2023] [Revised: 10/09/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
RNA-based therapy has been an expanding area of clinical research since the COVID-19 outbreak. Often, its comparison has been made to DNA-based gene therapy, such as adeno-associated virus- and lentivirus-mediated therapy. These DNA-based therapies show persistent expression, with maximized therapeutic efficacy. However, accumulating data indicate that proper control of gene expression is occasionally required. For example, in cancer immunotherapy, cytokine response syndrome is detrimental for host animals, while excess activation of the immune system induces supraphysiological cytokines. RNA-based therapy seems to be a rather mild therapy, and it has room to fit unmet medical needs, whereas current DNA-based therapy has unclear issues. This review focused on RNA-based therapy for cancer immunotherapy, hematopoietic disorders, and inherited disorders, which have received attention for possible clinical applications.
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Affiliation(s)
- Ryuichi Mashima
- Department of Clinical Laboratory Medicine, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
| | - Shuji Takada
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
| | - Yoshitaka Miyamoto
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
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4
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Stephenson AA, Nicolau S, Vetter TA, Dufresne GP, Frair EC, Sarff JE, Wheeler GL, Kelly BJ, White P, Flanigan KM. CRISPR-Cas9 homology-independent targeted integration of exons 1-19 restores full-length dystrophin in mice. Mol Ther Methods Clin Dev 2023; 30:486-499. [PMID: 37706184 PMCID: PMC10495553 DOI: 10.1016/j.omtm.2023.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 08/15/2023] [Indexed: 09/15/2023]
Abstract
Duchenne muscular dystrophy is an X-linked disorder typically caused by out-of-frame mutations in the DMD gene. Most of these are deletions of one or more exons, which can theoretically be corrected through CRISPR-Cas9-mediated knockin. Homology-independent targeted integration is a mechanism for achieving such a knockin without reliance on homology-directed repair pathways, which are inactive in muscle. We designed a system based on insertion into intron 19 of a DNA fragment containing a pre-spliced mega-exon encoding DMD exons 1-19, along with the MHCK7 promoter, and delivered it via a pair of AAV9 vectors in mice carrying a Dmd exon 2 duplication. Maximal efficiency was achieved using a Cas9:donor adeno-associated virus (AAV) ratio of 1:5, with Cas9 under the control of the SPc5-12 promoter. This approach achieved editing of 1.4% of genomes in the heart, leading to 30% correction at the transcript level and restoration of 11% of normal dystrophin levels. Treatment efficacy was lower in skeletal muscles. Sequencing additionally revealed integration of fragmentary and recombined AAV genomes at the target site. These data provide proof of concept for a gene editing system that could restore full-length dystrophin in individuals carrying mutations upstream of intron 19, accounting for approximately 25% of Duchenne muscular dystrophy patients.
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Affiliation(s)
- Anthony A. Stephenson
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Stefan Nicolau
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Tatyana A. Vetter
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
| | - Gabrielle P. Dufresne
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Emma C. Frair
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Jessica E. Sarff
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Gregory L. Wheeler
- The Institute for Genomic Medicine, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Benjamin J. Kelly
- The Institute for Genomic Medicine, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Peter White
- Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
- The Institute for Genomic Medicine, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Kevin M. Flanigan
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH 43210, USA
- Department of Neurology, The Ohio State University, Columbus, OH 43210, USA
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5
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Chey YCJ, Arudkumar J, Aartsma-Rus A, Adikusuma F, Thomas PQ. CRISPR applications for Duchenne muscular dystrophy: From animal models to potential therapies. WIREs Mech Dis 2023; 15:e1580. [PMID: 35909075 PMCID: PMC10078488 DOI: 10.1002/wsbm.1580] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/28/2022] [Accepted: 06/30/2022] [Indexed: 01/31/2023]
Abstract
CRISPR gene-editing technology creates precise and permanent modifications to DNA. It has significantly advanced our ability to generate animal disease models for use in biomedical research and also has potential to revolutionize the treatment of genetic disorders. Duchenne muscular dystrophy (DMD) is a monogenic muscle-wasting disease that could potentially benefit from the development of CRISPR therapy. It is commonly associated with mutations that disrupt the reading frame of the DMD gene that encodes dystrophin, an essential scaffolding protein that stabilizes striated muscles and protects them from contractile-induced damage. CRISPR enables the rapid generation of various animal models harboring mutations that closely simulates the wide variety of mutations observed in DMD patients. These models provide a platform for the testing of sequence-specific interventions like CRISPR therapy that aim to reframe or skip DMD mutations to restore functional dystrophin expression. This article is categorized under: Congenital Diseases > Genetics/Genomics/Epigenetics.
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Affiliation(s)
- Yu C J Chey
- School of Biomedicine and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Genome Editing Program, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Jayshen Arudkumar
- School of Biomedicine and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Genome Editing Program, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Fatwa Adikusuma
- School of Biomedicine and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Genome Editing Program, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.,CSIRO Synthetic Biology Future Science Platform, Canberra, Australia
| | - Paul Q Thomas
- School of Biomedicine and Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.,Genome Editing Program, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia.,South Australian Genome Editing (SAGE), South Australian Health and Medical Research Institute (SAHMRI), Adelaide, South Australia, Australia
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6
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Dubuisson N, Versele R, Planchon C, Selvais CM, Noel L, Abou-Samra M, Davis-López de Carrizosa MA. Histological Methods to Assess Skeletal Muscle Degeneration and Regeneration in Duchenne Muscular Dystrophy. Int J Mol Sci 2022; 23:16080. [PMID: 36555721 PMCID: PMC9786356 DOI: 10.3390/ijms232416080] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive disease caused by the loss of function of the protein dystrophin. This protein contributes to the stabilisation of striated cells during contraction, as it anchors the cytoskeleton with components of the extracellular matrix through the dystrophin-associated protein complex (DAPC). Moreover, absence of the functional protein affects the expression and function of proteins within the DAPC, leading to molecular events responsible for myofibre damage, muscle weakening, disability and, eventually, premature death. Presently, there is no cure for DMD, but different treatments help manage some of the symptoms. Advances in genetic and exon-skipping therapies are the most promising intervention, the safety and efficiency of which are tested in animal models. In addition to in vivo functional tests, ex vivo molecular evaluation aids assess to what extent the therapy has contributed to the regenerative process. In this regard, the later advances in microscopy and image acquisition systems and the current expansion of antibodies for immunohistological evaluation together with the development of different spectrum fluorescent dyes have made histology a crucial tool. Nevertheless, the complexity of the molecular events that take place in dystrophic muscles, together with the rise of a multitude of markers for each of the phases of the process, makes the histological assessment a challenging task. Therefore, here, we summarise and explain the rationale behind different histological techniques used in the literature to assess degeneration and regeneration in the field of dystrophinopathies, focusing especially on those related to DMD.
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Affiliation(s)
- Nicolas Dubuisson
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
- Neuromuscular Reference Center, Cliniques Universitaires Saint-Luc (CUSL), Avenue Hippocrate 10, 1200 Brussels, Belgium
| | - Romain Versele
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
| | - Chloé Planchon
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
| | - Camille M. Selvais
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
| | - Laurence Noel
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
| | - Michel Abou-Samra
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
| | - María A. Davis-López de Carrizosa
- Endocrinology, Diabetes and Nutrition Unit, Institute of Experimental and Clinical Research, Medical Sector, Université Catholique de Louvain (UCLouvain), Avenue Hippocrate 55, 1200 Brussels, Belgium
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain
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7
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Gushchina LV, Vetter TA, Frair EC, Bradley AJ, Grounds KM, Lay JW, Huang N, Suhaiba A, Schnell FJ, Hanson G, Simmons TR, Wein N, Flanigan KM. Systemic PPMO-mediated dystrophin expression in the Dup2 mouse model of Duchenne muscular dystrophy. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 30:479-492. [PMID: 36420217 PMCID: PMC9678653 DOI: 10.1016/j.omtn.2022.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 10/31/2022] [Indexed: 11/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a devastating muscle-wasting disease that arises due to the loss of dystrophin expression, leading to progressive loss of motor and cardiorespiratory function. Four exon-skipping approaches using antisense phosphorodiamidate morpholino oligomers (PMOs) have been approved by the FDA to restore a DMD open reading frame, resulting in expression of a functional but internally deleted dystrophin protein, but in patients with single-exon duplications, exon skipping has the potential to restore full-length dystrophin expression. Cell-penetrating peptide-conjugated PMOs (PPMOs) have demonstrated enhanced cellular uptake and more efficient dystrophin restoration than unconjugated PMOs. In the present study, we demonstrate widespread PPMO-mediated dystrophin restoration in the Dup2 mouse model of exon 2 duplication, representing the most common single-exon duplication among patients with DMD. In this proof-of-concept study, a single intravenous injection of PPMO targeting the exon 2 splice acceptor site induced 45% to 68% exon 2-skipped Dmd transcripts in Dup2 skeletal muscles 15 days post-injection. Muscle dystrophin restoration peaked at 77% to 87% average dystrophin-positive fibers and 41% to 51% of normal signal intensity by immunofluorescence, and 15.7% to 56.8% of normal by western blotting 15 to 30 days after treatment. These findings indicate that PPMO-mediated exon skipping is a promising therapeutic strategy for muscle dystrophin restoration in the context of exon 2 duplications.
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Affiliation(s)
- Liubov V. Gushchina
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Tatyana A. Vetter
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Emma C. Frair
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Adrienne J. Bradley
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Kelly M. Grounds
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Jacob W. Lay
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Nianyuan Huang
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Aisha Suhaiba
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | | | | | - Tabatha R. Simmons
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
| | - Nicolas Wein
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Kevin M. Flanigan
- The Center for Gene Therapy, Nationwide Children’s Hospital, Columbus, OH, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH, USA
- Department of Neurology, The Ohio State University, Columbus, OH, USA
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8
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Gomez Limia C, Baird M, Schwartz M, Saxena S, Meyer K, Wein N. Emerging Perspectives on Gene Therapy Delivery for Neurodegenerative and Neuromuscular Disorders. J Pers Med 2022; 12:1979. [PMID: 36556200 PMCID: PMC9788053 DOI: 10.3390/jpm12121979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 12/05/2022] Open
Abstract
Neurodegenerative disorders (NDDs), such as Alzheimer's disease (AD) and Parkinson's Disease (PD), are a group of heterogeneous diseases that mainly affect central nervous system (CNS) functions. A subset of NDDs exhibit CNS dysfunction and muscle degeneration, as observed in Gangliosidosis 1 (GM1) and late stages of PD. Neuromuscular disorders (NMDs) are a group of diseases in which patients show primary progressive muscle weaknesses, including Duchenne Muscular Dystrophy (DMD), Pompe disease, and Spinal Muscular Atrophy (SMA). NDDs and NMDs typically have a genetic component, which affects the physiological functioning of critical cellular processes, leading to pathogenesis. Currently, there is no cure or efficient treatment for most of these diseases. More than 200 clinical trials have been completed or are currently underway in order to establish safety, tolerability, and efficacy of promising gene therapy approaches. Thus, gene therapy-based therapeutics, including viral or non-viral delivery, are very appealing for the treatment of NDDs and NMDs. In particular, adeno-associated viral vectors (AAV) are an attractive option for gene therapy for NDDs and NMDs. However, limitations have been identified after systemic delivery, including the suboptimal capacity of these therapies to traverse the blood-brain barrier (BBB), degradation of the particles during the delivery, high reactivity of the patient's immune system during the treatment, and the potential need for redosing. To circumvent these limitations, several preclinical and clinical studies have suggested intrathecal (IT) delivery to target the CNS and peripheral organs via cerebrospinal fluid (CSF). CSF administration can vastly improve the delivery of small molecules and drugs to the brain and spinal cord as compared to systemic delivery. Here, we review AAV biology and vector design elements, different therapeutic routes of administration, and highlight CSF delivery as an attractive route of administration. We discuss the different aspects of neuromuscular and neurodegenerative diseases, such as pathogenesis, the landscape of mutations, and the biological processes associated with the disease. We also describe the hallmarks of NDDs and NMDs as well as discuss current therapeutic approaches and clinical progress in viral and non-viral gene therapy and enzyme replacement strategies for those diseases.
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Affiliation(s)
- Cintia Gomez Limia
- Center for Gene Therapy, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
| | - Megan Baird
- Center for Gene Therapy, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH 43205, USA
| | - Maura Schwartz
- Center for Gene Therapy, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH 43205, USA
| | - Smita Saxena
- Department of Neurology, Inselspital, 3010 Bern, Switzerland
| | - Kathrin Meyer
- Center for Gene Therapy, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH 43205, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA
| | - Nicolas Wein
- Center for Gene Therapy, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
- Biomedical Sciences Graduate Program, The Ohio State University College of Medicine, Columbus, OH 43205, USA
- Department of Pediatrics, The Ohio State University, Columbus, OH 43205, USA
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9
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Wein N, Vetter TA, Vulin A, Simmons TR, Frair EC, Bradley AJ, Gushchina LV, Almeida CF, Huang N, Lesman D, Rajakumar D, Weiss RB, Flanigan KM. Systemic delivery of an AAV9 exon-skipping vector significantly improves or prevents features of Duchenne muscular dystrophy in the Dup2 mouse. Mol Ther Methods Clin Dev 2022; 26:279-293. [PMID: 35949298 PMCID: PMC9356240 DOI: 10.1016/j.omtm.2022.07.005] [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: 03/26/2022] [Accepted: 07/08/2022] [Indexed: 11/17/2022]
Abstract
Duchenne muscular dystrophy (DMD) is typically caused by mutations that disrupt the DMD reading frame, but nonsense mutations in the 5′ part of the gene induce utilization of an internal ribosomal entry site (IRES) in exon 5, driving expression of a highly functional N-truncated dystrophin. We have developed an AAV9 vector expressing U7 small nuclear RNAs targeting DMD exon 2 and have tested it in a mouse containing a duplication of exon 2, in which skipping of both exon 2 copies induces IRES-driven expression, and skipping of one copy leads to wild-type dystrophin expression. One-time intravascular injection either at postnatal days 0–1 or at 2 months results in efficient exon skipping and dystrophin expression, and significant protection from functional and pathologic deficits. Immunofluorescence quantification showed 33%–53% average dystrophin intensity and 55%–79% average dystrophin-positive fibers in mice treated in adulthood, with partial amelioration of DMD pathology and correction of DMD-associated alterations in gene expression. In mice treated neonatally, dystrophin immunofluorescence reached 49%–85% of normal intensity and 76%–99% dystrophin-positive fibers, with near-complete correction of dystrophic pathology, and these beneficial effects persisted for at least 6 months. Our results demonstrate the robustness, durability, and safety of exon 2 skipping using scAAV9.U7snRNA.ACCA, supporting its clinical use.
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Affiliation(s)
- Nicolas Wein
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Tatyana A Vetter
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Adeline Vulin
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Tabatha R Simmons
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Emma C Frair
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Adrienne J Bradley
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Liubov V Gushchina
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Camila F Almeida
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Nianyuan Huang
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Daniel Lesman
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Dhanarajan Rajakumar
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA
| | - Robert B Weiss
- Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Kevin M Flanigan
- Center for Gene Therapy, The Abigail Wexner Research Institute, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA.,Department of Neurology, The Ohio State University, Columbus, OH, USA
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10
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Deng J, Zhang J, Shi K, Liu Z. Drug development progress in duchenne muscular dystrophy. Front Pharmacol 2022; 13:950651. [PMID: 35935842 PMCID: PMC9353054 DOI: 10.3389/fphar.2022.950651] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 06/28/2022] [Indexed: 12/22/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe, progressive, and incurable X-linked disorder caused by mutations in the dystrophin gene. Patients with DMD have an absence of functional dystrophin protein, which results in chronic damage of muscle fibers during contraction, thus leading to deterioration of muscle quality and loss of muscle mass over time. Although there is currently no cure for DMD, improvements in treatment care and management could delay disease progression and improve quality of life, thereby prolonging life expectancy for these patients. Furthermore, active research efforts are ongoing to develop therapeutic strategies that target dystrophin deficiency, such as gene replacement therapies, exon skipping, and readthrough therapy, as well as strategies that target secondary pathology of DMD, such as novel anti-inflammatory compounds, myostatin inhibitors, and cardioprotective compounds. Furthermore, longitudinal modeling approaches have been used to characterize the progression of MRI and functional endpoints for predictive purposes to inform Go/No Go decisions in drug development. This review showcases approved drugs or drug candidates along their development paths and also provides information on primary endpoints and enrollment size of Ph2/3 and Ph3 trials in the DMD space.
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Affiliation(s)
- Jiexin Deng
- School of Nursing and Health, Henan University, Kaifeng, China
- *Correspondence: Jiexin Deng, ; Zhigang Liu,
| | - Junshi Zhang
- Department of Neurology, Huaihe Hospital of Henan University, Kaifeng, China
| | - Keli Shi
- School of Medicine, Henan University, Kaifeng, China
| | - Zhigang Liu
- Department of Orthopedics, First Affiliated Hospital of Henan University, Kaifeng, China
- *Correspondence: Jiexin Deng, ; Zhigang Liu,
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11
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Happi Mbakam C, Lamothe G, Tremblay JP. Therapeutic Strategies for Dystrophin Replacement in Duchenne Muscular Dystrophy. Front Med (Lausanne) 2022; 9:859930. [PMID: 35419381 PMCID: PMC8995704 DOI: 10.3389/fmed.2022.859930] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/01/2022] [Indexed: 12/12/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked hereditary disease characterized by progressive muscle wasting due to modifications in the DMD gene (exon deletions, nonsense mutations, intra-exonic insertions or deletions, exon duplications, splice site defects, and deep intronic mutations) that result in a lack of functional dystrophin expression. Many therapeutic approaches have so far been attempted to induce dystrophin expression and improve the patient phenotype. In this manuscript, we describe the relevant updates for some therapeutic strategies for DMD aiming to restore dystrophin expression. We also present and analyze in vitro and in vivo ongoing experimental approaches to treat the disease.
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Affiliation(s)
- Cedric Happi Mbakam
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Gabriel Lamothe
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
| | - Jacques P Tremblay
- Centre de Recherche du CHU de Québec-Université Laval, Quebec City, QC, Canada.,Department of Molecular Medicine, Faculty of Medicine, Laval University, Quebec City, QC, Canada
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12
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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: 5.0] [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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13
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Wein N, Dunn DM, Waldrop MA, Gushchina LV, Frair EC, Weiss RB, Flanigan KM. Absence of Significant Off-Target Splicing Variation with a U7snRNA Vector Targeting DMD Exon 2 Duplications. Hum Gene Ther 2021; 32:1346-1359. [PMID: 34060935 DOI: 10.1089/hum.2020.315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Exon skipping therapies for Duchenne muscular dystrophy that restore an open reading frame can be induced by the use of noncoding U7 small nuclear RNA (U7snRNA) modified by an antisense exon-targeting sequence delivered by an adeno-associated virus (AAV) vector. We have developed an AAV vector (AAV9.U7-ACCA) containing four U7snRNAs targeting the splice donor and acceptor sites of dystrophin exon 2, resulting in highly efficient exclusion of DMD exon 2. We assessed the specificity of splice variation induced by AAV9.U7-ACCA delivery in the Dmd exon 2 duplication (Dup2) mouse model through an unbiased RNA-seq approach. Treatment-related effects on pre-mRNA splicing were quantified using local splicing variation (LSV) analysis. Filtering the transcriptome for differences in treatment-related splicing resulted in only 16 candidate off-target LSVs. Only a single candidate off-target LSV was found in both skeletal and cardiac muscle tissue and occurred at a known variable cassette exon. In contrast, four LSVs represented significant on-target correction of Dmd exon 2 splicing and transcriptome analysis showed correction of known dystrophin-deficient gene dysregulation. We conclude that the absence of off-target splicing induced by treatment with the U7-ACCA vector supports the continued clinical development of this approach.
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Affiliation(s)
- Nicolas Wein
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Diane M Dunn
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Megan A Waldrop
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Liubov V Gushchina
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Emma C Frair
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Robert B Weiss
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Kevin M Flanigan
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA.,Department of Neurology, The Ohio State University, Columbus, Ohio, USA
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14
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Maino E, Wojtal D, Evagelou SL, Farheen A, Wong TWY, Lindsay K, Scott O, Rizvi SZ, Hyatt E, Rok M, Visuvanathan S, Chiodo A, Schneeweiss M, Ivakine EA, Cohn RD. Targeted genome editing in vivo corrects a Dmd duplication restoring wild-type dystrophin expression. EMBO Mol Med 2021; 13:e13228. [PMID: 33724658 PMCID: PMC8103086 DOI: 10.15252/emmm.202013228] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 02/06/2021] [Accepted: 02/10/2021] [Indexed: 12/26/2022] Open
Abstract
Tandem duplication mutations are increasingly found to be the direct cause of many rare heritable diseases, accounting for up to 10% of cases. Unfortunately, animal models recapitulating such mutations are scarce, limiting our ability to study them and develop genome editing therapies. Here, we describe the generation of a novel duplication mouse model, harboring a multi-exonic tandem duplication in the Dmd gene which recapitulates a human mutation. Duplication correction of this mouse was achieved by implementing a single-guide RNA (sgRNA) CRISPR/Cas9 approach. This strategy precisely removed a duplication mutation in vivo, restored full-length dystrophin expression, and was accompanied by improvements in both histopathological and clinical phenotypes. We conclude that CRISPR/Cas9 represents a powerful tool to accurately model and treat tandem duplication mutations. Our findings will open new avenues of research for exploring the study and therapeutics of duplication disorders.
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Affiliation(s)
- Eleonora Maino
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Daria Wojtal
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Sonia L Evagelou
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Aiman Farheen
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Tatianna W Y Wong
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Kyle Lindsay
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Ori Scott
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
- Department of Pediatricsthe Hospital for Sick ChildrenTorontoONCanada
| | - Samar Z Rizvi
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Elzbieta Hyatt
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Matthew Rok
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
| | - Shagana Visuvanathan
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Amanda Chiodo
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Michelle Schneeweiss
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
| | - Evgueni A Ivakine
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of PhysiologyUniversity of TorontoTorontoONCanada
| | - Ronald D Cohn
- Program in Genetics and Genome Biologythe Hospital for Sick Children Research InstituteTorontoONCanada
- Department of Molecular GeneticsUniversity of TorontoTorontoONCanada
- Institute of Medical ScienceUniversity of TorontoTorontoONCanada
- Department of Pediatricsthe Hospital for Sick ChildrenTorontoONCanada
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15
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Gushchina LV, Frair EC, Rohan N, Bradley AJ, Simmons TR, Chavan HD, Chou HJ, Eggers M, Waldrop MA, Wein N, Flanigan KM. Lack of Toxicity in Nonhuman Primates Receiving Clinically Relevant Doses of an AAV9.U7snRNA Vector Designed to Induce DMD Exon 2 Skipping. Hum Gene Ther 2021; 32:882-894. [PMID: 33406986 PMCID: PMC10112461 DOI: 10.1089/hum.2020.286] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Therapeutic exon skipping as a treatment for Duchenne muscular dystrophy (DMD) has largely concentrated on the delivery of antisense oligomers to treat out-of-frame exon deletions. Here we report on the preclinical development of an adeno-associated virus (AAV)-encapsidated viral vector containing four copies of the noncoding U7 small nuclear RNA (U7snRNA), each targeted to either the splice donor or the splice acceptor sites of DMD exon 2. We have previously shown that delivery of this vector (scAAV9.U7.ACCA) to the Dup2 mouse model results in expression of full-length dystrophin from wild-type DMD mRNA, as well as an internal ribosome entry site (IRES)-driven isoform translated only in the absence of exon 2 (deletion exon 2 [Del2] mRNA). Here we present the data from a rigorous dose escalation toxicity study in nonhuman primates, encompassing two doses (3 × 1013 and 8 × 1013 vg/kg) and two time points (3 and 6 months postinjection). No evidence for significant toxicity was seen by biochemical, histopathologic, or clinical measures, providing evidence for safety that led to initiation of a first-in-human clinical trial.
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Affiliation(s)
- Liubov V Gushchina
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA
| | - Emma C Frair
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA
| | - Natalie Rohan
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA
| | - Adrienne J Bradley
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA
| | - Tabatha R Simmons
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA
| | | | | | | | - Megan A Waldrop
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Nicolas Wein
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Kevin M Flanigan
- The Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA.,Department of Neurology, The Ohio State University, Columbus, Ohio, USA
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16
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Pre-clinical dose-escalation studies establish a therapeutic range for U7snRNA-mediated DMD exon 2 skipping. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 21:325-340. [PMID: 33898631 PMCID: PMC8047432 DOI: 10.1016/j.omtm.2021.03.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 03/18/2021] [Indexed: 01/09/2023]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked progressive disease characterized by loss of dystrophin protein that typically results from truncating mutations in the DMD gene. Current exon-skipping therapies have sought to treat deletion mutations that abolish an open reading frame (ORF) by skipping an adjacent exon, in order to restore an ORF that allows translation of an internally deleted yet partially functional protein, as is seen with many patients with the milder Becker muscular dystrophy (BMD) phenotype. In contrast to that approach, skipping of one copy of a duplicated exon would be expected to result in a full-length transcript and production of a wild-type protein. We have developed an adeno-associated virus (AAV)-based U7snRNA exon-skipping approach directed toward exon 2, duplications of which represent 10% of all DMD duplication mutations. Deletion of exon 2 results in utilization of an exon 5 internal ribosome entry site (IRES) that allows translation beginning in exon 6 of a highly protective dystrophin protein, providing a wide therapeutic window for treatment. Both intramuscular and systemic administration of this vector in the Dup2 mouse model results in robust dystrophin expression and correction of muscle physiologic defects, allowing dose escalation to establish a putative minimal efficacious dose for a human clinical trial.
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17
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Barthélémy I, Calmels N, Weiss RB, Tiret L, Vulin A, Wein N, Peccate C, Drougard C, Beroud C, Deburgrave N, Thibaud JL, Escriou C, Punzón I, Garcia L, Kaplan JC, Flanigan KM, Leturcq F, Blot S. X-linked muscular dystrophy in a Labrador Retriever strain: phenotypic and molecular characterisation. Skelet Muscle 2020; 10:23. [PMID: 32767978 PMCID: PMC7412789 DOI: 10.1186/s13395-020-00239-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 07/09/2020] [Indexed: 12/24/2022] Open
Abstract
Background Canine models of Duchenne muscular dystrophy (DMD) are a valuable tool to evaluate potential therapies because they faithfully reproduce the human disease. Several cases of dystrophinopathies have been described in canines, but the Golden Retriever muscular dystrophy (GRMD) model remains the most used in preclinical studies. Here, we report a new spontaneous dystrophinopathy in a Labrador Retriever strain, named Labrador Retriever muscular dystrophy (LRMD). Methods A colony of LRMD dogs was established from spontaneous cases. Fourteen LRMD dogs were followed-up and compared to the GRMD standard using several functional tests. The disease causing mutation was studied by several molecular techniques and identified using RNA-sequencing. Results The main clinical features of the GRMD disease were found in LRMD dogs; the functional tests provided data roughly overlapping with those measured in GRMD dogs, with similar inter-individual heterogeneity. The LRMD causal mutation was shown to be a 2.2-Mb inversion disrupting the DMD gene within intron 20 and involving the TMEM47 gene. In skeletal muscle, the Dp71 isoform was ectopically expressed, probably as a consequence of the mutation. We found no evidence of polymorphism in either of the two described modifier genes LTBP4 and Jagged1. No differences were found in Pitpna mRNA expression levels that would explain the inter-individual variability. Conclusions This study provides a full comparative description of a new spontaneous canine model of dystrophinopathy, found to be phenotypically equivalent to the GRMD model. We report a novel large DNA mutation within the DMD gene and provide evidence that LRMD is a relevant model to pinpoint additional DMD modifier genes.
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Affiliation(s)
- Inès Barthélémy
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Nadège Calmels
- Laboratoire de biochimie et génétique moléculaire, hôpital Cochin, AP-HP, université Paris Descartes-Sorbonne Paris Cité, Paris, France.,Laboratoire de Diagnostic Génétique-Institut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de Strasbourg, 1 Place de L'Hôpital, 67091, Strasbourg, France
| | - Robert B Weiss
- Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Laurent Tiret
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Adeline Vulin
- SQY Therapeutics, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France
| | - Nicolas Wein
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Cécile Peccate
- SQY Therapeutics, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France.,Sorbonne Universités, UPMC Université Paris 06, INSERM UMRS974, Centre de Recherche en Myologie, Institut de Myologie, G.H. Pitié Salpêtrière, Paris, France
| | - Carole Drougard
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Christophe Beroud
- Aix Marseille Université, INSERM, MMG, Bioinformatics & Genetics, Marseille, France.,APHM, Hôpital Timone Enfants, Laboratoire de Génétique Moléculaire, Marseille, France
| | - Nathalie Deburgrave
- Laboratoire de biochimie et génétique moléculaire, hôpital Cochin, AP-HP, université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Jean-Laurent Thibaud
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Catherine Escriou
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Isabel Punzón
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France
| | - Luis Garcia
- Université de Versailles Saint-Quentin-en-Yvelines, U1179 INSERM, UFR des Sciences de la Santé, Montigny le Bretonneux, France
| | - Jean-Claude Kaplan
- Laboratoire de biochimie et génétique moléculaire, hôpital Cochin, AP-HP, université Paris Descartes-Sorbonne Paris Cité, Paris, France
| | - Kevin M Flanigan
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA.,Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - France Leturcq
- Laboratoire de biochimie et génétique moléculaire, hôpital Cochin, AP-HP, université Paris Descartes-Sorbonne Paris Cité, Paris, France.,Sorbonne Universités, UPMC Université Paris 06, INSERM UMRS974, Centre de Recherche en Myologie, Institut de Myologie, G.H. Pitié Salpêtrière, Paris, France
| | - Stéphane Blot
- U955 - IMRB, Team 10 - Biology of the neuromuscular system, Inserm, UPEC, EFS, Ecole nationale vétérinaire d'Alfort, 94700, Maisons-Alfort, France.
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18
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Greer K, Johnsen R, Nevo Y, Fellig Y, Fletcher S, Wilton SD. Single Exon Skipping Can Address a Multi-Exon Duplication in the Dystrophin Gene. Int J Mol Sci 2020; 21:ijms21124511. [PMID: 32630425 PMCID: PMC7350004 DOI: 10.3390/ijms21124511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 12/13/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe muscle wasting disease typically caused by protein-truncating mutations that preclude synthesis of a functional dystrophin. Exonic deletions are the most common type of DMD lesion, however, whole exon duplications account for between 10–15% of all reported mutations. Here, we describe in vitro evaluation of antisense oligonucleotide-induced splice switching strategies to re-frame the transcript disrupted by a multi-exon duplication within the DMD gene. Phosphorodiamidate morpholino oligomers and phosphorodiamidate morpholino oligomers coupled to a cell penetrating peptide were evaluated in a Duchenne muscular dystrophy patient cell strain carrying an exon 14–17 duplication. Two strategies were employed; the conventional approach was to remove both copies of exon 17 in addition to exon 18, and the second strategy was to remove only the first copy of exon 17. Both approaches result in a larger than normal but in-frame DMD transcript, but surprisingly, the removal of only the first exon 17 appeared to be more efficient in restoring dystrophin, as determined using western blotting. The emergence of a normal sized DMD mRNA transcript that was not apparent in untreated samples may have arisen from back splicing and could also account for some of the dystrophin protein being produced.
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Affiliation(s)
- Kane Greer
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch 6150, Australia
- Perron Institute for Neurological and Translational Science, Perth 6009, Australia
| | - Russell Johnsen
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch 6150, Australia
- Perron Institute for Neurological and Translational Science, Perth 6009, Australia
| | - Yoram Nevo
- Institute of Neurology, Schneider Children's Medical Center of Israel, Tel-Aviv University,Tel-Aviv 62919, Israel
| | - Yakov Fellig
- Pathology Department, Hadassah-Hebrew-University Medical Center, Jerusalem 91120, Israel
| | - Susan Fletcher
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch 6150, Australia
- Perron Institute for Neurological and Translational Science, Perth 6009, Australia
- Centre for Neuromuscular & Neurological Disorders, University of Western Australia, Perth 6009, Australia
| | - Steve D Wilton
- Centre for Molecular Medicine and Innovative Therapeutics, Murdoch University, Murdoch 6150, Australia
- Perron Institute for Neurological and Translational Science, Perth 6009, Australia
- Centre for Neuromuscular & Neurological Disorders, University of Western Australia, Perth 6009, Australia
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19
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Wasala NB, Chen SJ, Duan D. Duchenne muscular dystrophy animal models for high-throughput drug discovery and precision medicine. Expert Opin Drug Discov 2020; 15:443-456. [PMID: 32000537 PMCID: PMC7065965 DOI: 10.1080/17460441.2020.1718100] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 01/15/2020] [Indexed: 02/07/2023]
Abstract
Introduction: Duchenne muscular dystrophy (DMD) is an X-linked handicapping disease due to the loss of an essential muscle protein dystrophin. Dystrophin-null animals have been extensively used to study disease mechanisms and to develop experimental therapeutics. Despite decades of research, however, treatment options for DMD remain very limited.Areas covered: High-throughput high-content screening and precision medicine offer exciting new opportunities. Here, the authors review animal models that are suitable for these studies.Expert opinion: Nonmammalian models (worm, fruit fly, and zebrafish) are particularly attractive for cost-effective large-scale drug screening. Several promising lead compounds have been discovered using these models. Precision medicine for DMD aims at developing mutation-specific therapies such as exon-skipping and genome editing. To meet these needs, models with patient-like mutations have been established in different species. Models that harbor hotspot mutations are very attractive because the drugs developed in these models can bring mutation-specific therapies to a large population of patients. Humanized hDMD mice carry the entire human dystrophin gene in the mouse genome. Reagents developed in the hDMD mouse-based models are directly translatable to human patients.
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Affiliation(s)
- Nalinda B. Wasala
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212
| | - Shi-jie Chen
- Department of Physics, The University of Missouri, Columbia, MO 65211
- Department of Biochemistry, The University of Missouri, Columbia, MO 65211
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65212
- Department of Neurology, School of Medicine, The University of Missouri, Columbia, MO 65212
- Department of Biomedical, Biological & Chemical Engineering, College of Engineering, The University of Missouri, Columbia, MO 65212
- Department of Biomedical Sciences, College of Veterinary Medicine, The University of Missouri, Columbia, MO 65212
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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: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [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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21
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Abstract
The ability to efficiently modify the genome using CRISPR technology has rapidly revolutionized biology and genetics and will soon transform medicine. Duchenne muscular dystrophy (DMD) represents one of the first monogenic disorders that has been investigated with respect to CRISPR-mediated correction of causal genetic mutations. DMD results from mutations in the gene encoding dystrophin, a scaffolding protein that maintains the integrity of striated muscles. Thousands of different dystrophin mutations have been identified in DMD patients, who suffer from a loss of ambulation followed by respiratory insufficiency, heart failure, and death by the third decade of life. Using CRISPR to bypass DMD mutations, dystrophin expression has been efficiently restored in human cells and mouse models of DMD. Here, we review recent progress toward the development of possible CRISPR therapies for DMD and highlight opportunities and potential obstacles in attaining this goal.
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Affiliation(s)
- Yi-Li Min
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Rhonda Bassel-Duby
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Eric N Olson
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, and Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
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22
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Zhang Y, Long C, Bassel-Duby R, Olson EN. Myoediting: Toward Prevention of Muscular Dystrophy by Therapeutic Genome Editing. Physiol Rev 2018; 98:1205-1240. [PMID: 29717930 PMCID: PMC6335101 DOI: 10.1152/physrev.00046.2017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/22/2017] [Accepted: 12/26/2017] [Indexed: 12/22/2022] Open
Abstract
Muscular dystrophies represent a large group of genetic disorders that significantly impair quality of life and often progress to premature death. There is no effective treatment for these debilitating diseases. Most therapies, developed to date, focus on alleviating the symptoms or targeting the secondary effects, while the underlying gene mutation is still present in the human genome. The discovery and application of programmable nucleases for site-specific DNA double-stranded breaks provides a powerful tool for precise genome engineering. In particular, the CRISPR/Cas system has revolutionized the genome editing field and is providing a new path for disease treatment by targeting the disease-causing genetic mutations. In this review, we provide a historical overview of genome-editing technologies, summarize the most recent advances, and discuss potential strategies and challenges for permanently correcting genetic mutations that cause muscular dystrophies.
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Affiliation(s)
- Yu Zhang
- 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
| | - 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
| | - 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
| | - 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
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23
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Wein N, Vulin A, Findlay AR, Gumienny F, Huang N, Wilton SD, Flanigan KM. Efficient Skipping of Single Exon Duplications in DMD Patient-Derived Cell Lines Using an Antisense Oligonucleotide Approach. J Neuromuscul Dis 2018; 4:199-207. [PMID: 28869484 DOI: 10.3233/jnd-170233] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Exon skipping strategies in Duchenne muscular dystrophy (DMD) have largely been directed toward altering splicing of exons flanking out-of-frame deletions, with the goal of restoring an open mRNA reading frame that leads to production of an internally deleted but partially functional dystrophin protein. OBJECTIVE We sought to apply exon skipping to duplication mutations, assuming that the inherently limited efficiency of antisense oligonucleotide-induced exon skipping would more frequently skip a single copy of a duplicated exon, rather than both and result in significant amounts of wild-type DMD mRNA. METHODS We tested this hypothesis in fibroblast cell lines derived from patients with a variety of single or multiple exon duplications that have been modified to allow transdifferentiation into a myogenic lineage. RESULTS Using a variety of 2'O-methyl antisense oligonucleotides, significant skipping was induced for each duplication leading to a wild-type transcript as a major mRNA product. CONCLUSIONS This study provides another proof of concept for the feasibility of therapeutic skipping in patients carrying exon duplications in order to express wild-type, full-length mRNA, although careful evaluation of the skipping efficiency should be performed as some exons are easier to skip than others. Such a personalized strategy is expected to be highly beneficial for this subset of DMD patients, compared to inducing expression of an internally-deleted dystrophin.
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Affiliation(s)
- Nicolas Wein
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Adeline Vulin
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Andrew R Findlay
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Felecia Gumienny
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Nianyuan Huang
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Steve D Wilton
- Perron Institute for Neurological and Translational Science, Center for Comparative Genomics, Murdoch University, Perth, Australia
| | - Kevin M Flanigan
- The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA.,Department of Neurology, The Ohio State University, Columbus, OH, USA
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Niks EH, Aartsma-Rus A. Exon skipping: a first in class strategy for Duchenne muscular dystrophy. Expert Opin Biol Ther 2016; 17:225-236. [PMID: 27936976 DOI: 10.1080/14712598.2017.1271872] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
INTRODUCTION Exon skipping is a therapeutic approach for Duchenne muscular dystrophy (DMD) that has been in development for close to two decades. This approach uses antisense oligonucleotides (AONs) to modulate pre-mRNA splicing of dystrophin transcripts to restore the disrupted DMD reading frame. The approach has moved from in vitro proof of concept studies to the clinical trial phase and marketing authorization applications with regulators. The first AON (eteplirsen) has recently received accelerated approval by the Food and Drug Administration in the US. Areas covered: In this review the authors explain the antisense-mediated exon skipping approach, outline how it needs be tailored for different DMD mutation types and describe the challenges and opportunities for each mutation type. The authors summarize the clinical development of antisense-mediated exon 51 skipping, and discuss methods to improve efficiency. Finally, the authors provide their opinion on current developments and identify topics for future prioritization. Expert opinion: Exon skipping development has been a learning experience for all those involved. Aside from an approved therapy, its development has yielded side benefits including the development of tools for clinical trials and has increased collaboration between academics, patients, industry and regulators.
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Affiliation(s)
- Erik H Niks
- a Department of Neurology , Leiden University Medical Center , Leiden , The Netherlands
| | - Annemieke Aartsma-Rus
- b Department of Human Genetics , Leiden University Medical Center , Leiden , The Netherlands
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