title: Delivery of AAV2/9-microdystrophin genes incorporating helix 1 of the coiled-coil motif in the C-terminal domain of dystrophin improves muscle pathology and restores the level of α1-syntrophin and α-dystrobrevin in skeletal muscles of mdx mice.
abstract: Duchenne muscular dystrophy is a severe X-linked inherited muscle wasting disorder caused by mutations in the dystrophin gene. Adeno-associated virus (AAV) vectors have been extensively used to deliver genes efficiently for dystrophin expression in skeletal muscles. To overcome limited packaging capacity of AAV vectors (<5 kb), truncated recombinant microdystrophin genes with deletions of most of rod and carboxyl-terminal (CT) domains of dystrophin have been developed. We have previously shown the efficiency of mRNA sequence-optimized microdystrophin (ΔR4-23/ΔCT, called MD1) with deletion of spectrin-like repeat domain 4 to 23 and CT domain in ameliorating the pathology of dystrophic mdx mice. However, the CT domain of dystrophin is thought to recruit part of the dystrophin-associated protein complex, which acts as a mediator of signaling between extracellular matrix and cytoskeleton in muscle fibers. In this study, we extended the ΔR4-23/ΔCT microdystrophin by incorporating helix 1 of the coiled-coil motif in the CT domain of dystrophin (MD2), which contains the α1-syntrophin and α-dystrobrevin binding sites. Intramuscular injection of AAV2/9 expressing CT domain-extended microdystrophin showed efficient dystrophin expression in tibialis anterior muscles of mdx mice. The presence of the CT domain of dystrophin in MD2 increased the recruitment of α1-syntrophin and α-dystrobrevin at the sarcolemma and significantly improved the muscle resistance to lengthening contraction-induced muscle damage in the mdx mice compared with MD1. These results suggest that the incorporation of helix 1 of the coiled-coil motif in the CT domain of dystrophin to the microdystrophins will substantially improve their efficiency in restoring muscle function in patients with Duchenne muscular dystrophy.
authors: SWAN Institute of Biomedical and Life Sciences, School of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom.
authors: Taeyoung
authors: T
authors: Koo
authors: Alberto
authors: A
authors: Malerba
authors: Takis
authors: T
authors: Athanasopoulos
authors: Capucine
authors: C
authors: Trollet
authors: Luisa
authors: L
authors: Boldrin
authors: Arnaud
authors: A
authors: Ferry
authors: Linda
authors: L
authors: Popplewell
authors: Helen
authors: H
authors: Foster
authors: Keith
authors: K
authors: Foster
authors: George
authors: G
authors: Dickson
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D000229:Dependovirus / Q000235:genetics*; D016189:Dystrophin / Q000235:genetics* / Q000378:metabolism; D049029:Dystrophin-Associated Proteins / Q000378:metabolism*; D015316:Genetic Therapy; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D018101:Mice, Inbred mdx; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009137:Muscular Dystrophy, Animal / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics / Q000473:pathology / Q000628:therapy*
chemical_list: D002135:Calcium-Binding Proteins; D016189:Dystrophin; D049029:Dystrophin-Associated Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; C098885:dystrobrevin; C091825:syntrophin alpha1