Exercise and PGC-1?-independent synchronization of type I muscle metabolism and vasculature by ERR?.

ABSTRACT: How type I skeletal muscle inherently maintains high oxidative and vascular capacity in the absence of exercise is unclear. We show that nuclear receptor ERR? is highly expressed in type I muscle and, when transgenically expressed in anaerobic type II muscles (ERRGO mice), dually induces metabolic and vascular transformation in the absence of exercise. ERRGO mice show increased expression of genes promoting fat metabolism, mitochondrial respiration, and type I fiber specification. Muscles in ERRGO mice also display an activated angiogenic program marked by myofibrillar induction and secretion of proangiogenic factors, neovascularization, and a 100% increase in running endurance. Surprisingly, the induction of type I muscle properties by ERR? does not involve PGC-1?. Instead, ERR? genetically activates the energy sensor AMPK in mediating the metabovascular changes in ERRGO mice. Therefore, ERR? represents a previously unrecognized determinant that specifies intrinsic vascular and oxidative metabolic features that distinguish type I from type II muscle.

SUBMITTER: Narkar VA 

PROVIDER: S-EPMC3084588 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature