KLF15- and glucocorticoid-dependent transcriptional responses in mouse muscle.. Mus musculus

Excessive or sustained glucocorticoid (GC) exposure causes muscle wasting. Paradoxically, moderate or transient GC exposure elicits ergogenic effects, evidenced by their widespread use as doping agents by endurance athletes and poorly understood efficacy in Duchenne muscular dystrophy (DMD), a genetic muscle wasting disease. While mechanisms underlying GC-mediated muscle wasting are well defined, the molecular basis for the latter remains unknown. In this arm of our studies, Wild-type (WT) and Klf15-/- (KO) mice were given the potent GC receptor agonist dexamethasone (dex) and quadriceps tissue was subjected to transcript expression profiling by cDNA microarrays. Overall design: Total RNA was isolated from the quadriceps of KLF15 WT and KO mice 8 hours after treatment with dexamethasone or vehicle (4 animals per group) and hybridized to single-color Agilent 4x44K arrays to determine transcriptional responses to glucocorticoids and their dependence on KLF15 expression.