title: Restriction of calpain3 expression to the skeletal muscle prevents cardiac toxicity and corrects pathology in a murine model of limb-girdle muscular dystrophy.
abstract: BACKGROUND
  Genetic defects in calpain3 (CAPN3) lead to limb-girdle muscular dystrophy type 2A, a disease of the skeletal muscle that affects predominantly the proximal limb muscles. We previously demonstrated the potential of adeno-associated virus-mediated transfer of the CAPN3 gene to correct the pathological signs in a murine model for limb-girdle muscular dystrophy type 2A after intramuscular and locoregional administrations.
  
  
  RESULTS
  Here, we showed that intravenous injection of calpain3-expressing vector in mice can induce mortality in a dose-dependent manner. An anatomopathological investigation revealed large areas of fibrosis in the heart that we related to unregulated proteolytic activity of calpain3. To circumvent this toxicity, we developed new adeno-associated virus vectors with skeletal muscle-restricted expression by using new muscle-specific promoters that include the CAPN3 promoter itself and by introducing a target sequence of the cardiac-specific microRNA-208a in the cassette. Our results show that CAPN3 transgene expression can be successfully suppressed in the cardiac tissue, preventing the cardiac toxicity, whereas expression of the transgene in skeletal muscle reverts the pathological signs of calpain3 deficiency.
  
  
  CONCLUSIONS
  The molecular strategies used in this study may be useful for any gene transfer strategy with potential toxicity in the heart.
authors.affiliation: Généthon, CNRS-UMR8587, Université d'Evry Val d'Essonne, 1 rue de l’Internationale, Evry, France.
authors.forename: Carinne
authors.initials: C
authors.lastname: Roudaut
authors.forename: Florence
authors.initials: F
authors.lastname: Le Roy
authors.forename: Laurence
authors.initials: L
authors.lastname: Suel
authors.forename: Jérôme
authors.initials: J
authors.lastname: Poupiot
authors.forename: Karine
authors.initials: K
authors.lastname: Charton
authors.forename: Marc
authors.initials: M
authors.lastname: Bartoli
authors.forename: Isabelle
authors.initials: I
authors.lastname: Richard
mesh_terms: D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D057809:HEK293 Cells; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009124:Muscle Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000473:pathology*; D049288:Muscular Dystrophies, Limb-Girdle / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*
chemical_list: D009124:Muscle Proteins; D002154:Calpain; C491373:Capn3 protein, mouse
keywords: death, sudden; genetic therapy; microRNAs; muscles