Posttranscriptional mechanisms involving microRNA-27a and b contribute to fast-specific and glucocorticoid-mediated myostatin expression in skeletal muscle.

ABSTRACT: Expression of the antigrowth factor myostatin (MSTN) differs between fast and slow skeletal muscles and is increased in nearly every form of muscle atrophy, but the contribution of transcriptional vs. posttranscriptional mechanisms to its differing expression in these states has not been defined. We show here that levels of mature MSTN mRNA were sixfold greater in fast vs. slow muscle and were increased twofold in fast muscle in response to dexamethasone (Dex) injection in vivo and in C₂C₁₂ myotubes following Dex treatment in vitro, but that levels of MSTN pre-mRNA, a readout of transcription, only minimally and nonsignificantly differed in these states. Moreover, Dex treatment with or without cotransfection with a glucocorticoid receptor expression construct had only modest effects on mou

SUBMITTER: Allen DL 

PROVIDER: S-EPMC3023185 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature