VEGF overexpression via adeno-associated virus gene transfer promotes skeletal muscle regeneration and enhances muscle function in mdx mice

Vascular endothelial growth factor (VEGF) is a major regulator of physiological and pathological angiogenesis. Recently it was reported that the delivery of VEGF using recombinant adenoassociated virus (rAAV) vectors reduces muscle damage and promotes muscle regeneration in different experimental models of muscle necrosis. We demonstrate that intramuscular administration of rAAVVEGF improved pathophysiology of the mdx mouse, a model of Duchenne muscular dystrophy (DMD). One month after injection, rAAV-VEGF-treated muscles showed augmented expression of VEGF and immunolocalization of its receptor, VEGFR-2. VEGFtreated mdx mice showed increased forelimb strength and strength normalized to weight. Treatment reduced necrotic fibers area and increased regenerating fibers area with an augmented number of myogenin- positive satellite cells and myonuclei, and of developmental myosin heavy chain-positive fibers. Only the regenerating area showed increased capillary density. This study provides novel evidence of a VEGF beneficial effect in mdx mice that is exerted mainly by a proregenerative and angiogenic effect. It opens new therapeutic prospectives in DMD and other types of muscular disorders.—Messina, S., Mazzeo, A., Bitto, A., Aguennouz, M., Migliorato, A., De Pasquale, M. G., Minutoli, L., Altavilla, D., Zentilin, L., Giacca, M., Squadrito, F., Vita, G. VEGF overexpression via adeno-associated virus gene transfer promotes skeletal muscle regeneration and enhances muscle function in mdx mice