title: Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy.
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 skipdystrophinexons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMDJdogs. 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 CXMDJdogs 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.
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Echigoya
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.|Third Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Nagano 390-8621, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Nakamura
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagata
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.|Department of Cardiovascular Internal Medicine, Nagano Red Cross Hospital, Nagano 380-8582, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Urasawa
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7.
authors.forename: Kenji Rowel Q
authors.identifier: 0000-0002-5484-4183
authors.initials: KRQ
authors.lastname: Lim
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7.
authors.forename: Nhu
authors.initials: N
authors.lastname: Trieu
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7.
authors.forename: Dharminder
authors.initials: D
authors.lastname: Panesar
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Kuraoka
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.
authors.forename: Hong M
authors.initials: HM
authors.lastname: Moulton
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Sarepta Therapeutics, Inc., Cambridge, MA 02142.
authors.forename: Patrick
authors.initials: P
authors.lastname: Iversen
authors.affiliation: Sarepta Therapeutics, Inc., Cambridge, MA 02142.
authors.forename: Peter
authors.initials: P
authors.lastname: Sazani
authors.affiliation: Sarepta Therapeutics, Inc., Cambridge, MA 02142.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Kole
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7.
authors.forename: Rika
authors.initials: R
authors.lastname: Maruyama
authors.affiliation: Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC 20010.|Department of Integrative Systems Biology, George Washington University School of Medicine, Washington, DC 20010.
authors.forename: Terry
authors.initials: T
authors.lastname: Partridge
authors.affiliation: Department of Molecular Therapy, National Center of Neurology and Psychiatry, National Institute of Neuroscience, Kodaira, Tokyo 187-8502, Japan; takeda@ncnp.go.jp toshifum@ualberta.ca.
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Takeda
authors.affiliation: Department of Medical Genetics, School of Human Development, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada T6G 2H7; takeda@ncnp.go.jp toshifum@ualberta.ca.|The Friends of Garrett Cumming Research & Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, AB, Canada T6G 2H7.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yokota
mesh_terms: D000818:Animals; D009202:Cardiomyopathies / Q000209:etiology / Q000628:therapy*; D057846:Cell-Penetrating Peptides / Q000494:pharmacology*; D004195:Disease Models, Animal; D004285:Dogs; D016189:Dystrophin / Q000378:metabolism*; D005091:Exons; D005260:Female; D015316:Genetic Therapy; D008297:Male; D060172:Morpholinos / Q000494:pharmacology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009137:Muscular Dystrophy, Animal / Q000150:complications / Q000235:genetics / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000150:complications / Q000235:genetics / Q000628:therapy*
chemical_list: D057846:Cell-Penetrating Peptides; D016189:Dystrophin; D060172:Morpholinos
keywords: Duchenne muscular dystrophy; cardiac Purkinje fibers; dystrophic dog model; exon skipping; peptide-conjugated morpholinos