title: Skeletal muscle regeneration in mice is stimulated by local overexpression of V1a-vasopressin receptor.
abstract: Skeletal muscle has a remarkable capacity to regenerate after mechanical or pathological injury. We show that the V1a receptor (V1aR) for vasopressin, a potent myogenic-promoting factor that stimulates differentiation and hypertrophy in vitro, is expressed in mouse skeletal muscle and modulated during regeneration after experimental injury. We used gene delivery by electroporation to overexpress the myc-tagged vasopressin V1aR in specific muscles, thus sensitizing them to circulating vasopressin. The correct localization on the surface of the fibers of the recombinant product was demonstrated by confocal immunofluorescence directed against the myc tag. V1aR overexpression dramatically enhanced regeneration. When compared with mock-transfected controls, V1aR overexpressing muscles exhibited significantly accelerated activation of satellite cells and increased expression of differentiation markers. Downstream of V1aR activation, calcineurin was strongly up-regulated and stimulated the expression of IL-4, a potent mediator of myogenic cell fusion. The central role of calcineurin in mediating V1aR-dependent myogenesis was also demonstrated by using its specific inhibitor, cyclosporine A. This study identifies skeletal muscle as a physiological target of hormones of the vasopressin family and reveals a novel in vivo role for vasopressin-dependent pathways. These findings unveil several steps, along a complex signaling pathway, that may be exploited as potential targets for the therapy of diseases characterized by altered muscle homeostasis and regeneration.
authors.affiliation: Department of Anatomical, Histological, Forensic, and Orthopaedic Sciences, Sapienza University of Rome, Rome, Italy.
authors.forename: Angelica
authors.initials: A
authors.lastname: Toschi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Severi
authors.forename: Dario
authors.initials: D
authors.lastname: Coletti
authors.forename: Angela
authors.initials: A
authors.lastname: Catizone
authors.forename: Antonio
authors.initials: A
authors.lastname: Musarò
authors.forename: Mario
authors.initials: M
authors.lastname: Molinaro
authors.forename: Clara
authors.initials: C
authors.lastname: Nervi
authors.forename: Sergio
authors.initials: S
authors.lastname: Adamo
authors.forename: Bianca Maria
authors.initials: BM
authors.lastname: Scicchitano
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D015415:Biomarkers / Q000378:metabolism; D019703:Calcineurin / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D003893:Desmin / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017483:Receptors, Vasopressin / Q000235:genetics / Q000378:metabolism*; D012038:Regeneration / Q000187:drug effects / Q000502:physiology*; D032496:Satellite Cells, Skeletal Muscle / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection
chemical_list: D015415:Biomarkers; D003893:Desmin; D012333:RNA, Messenger; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin; D015847:Interleukin-4; D019703:Calcineurin