Effects Of Exercise On The Accociation Of HDAC5 With MEF2 In Skeletal Muscle Of Different Genotypic Mice Of AMPK

Alghough it is well established that exercise increases the binding of MEF2A to its cis-element on the GLUT4 promoter and GLUT4 expression, little is known about the intracellular signaling pathways involved in eliciting this response. The role of AMPKa 2 in regulating the exercise induced MEF2A nucleus translocation, MEF2A binding to the Glut4 promoter, and Glut4 expression was investigated in the present study. This was investigated in muscles from AMPKα2 over-expression (OE) mice, AMPKα2 knockout (KO) mice and corresponding wild-type (WT) mice that had undertaken a 28-days program of treadmill training.1) AMPKα-Thr172 phosphorylation by western blot.2) Total and nuclear MEF2A by western bolt.3) Bound MEF2A at the GLUT4 MEF2 cis-element by CHIP.4) GLUT4 expression by Real Time-PCR and Western blot. Over-expression of the AMPKα2 isofurm heightened the training-induced increase in nuclear MEF2A content, MEF2A binding to the Glut4 promoter and GLUT4 expression, and that the training-induced increases of Glut4 promoter-bound MFF2A and GLUT4 expression were normal inα2-KO muscles despite the reduced AMPK signaling, nuclear MEF2 content, suggest that AMPKa 2 is involved, though not indispensable, in regulating training-induced MEF2A binding to the Glut4 promoter and GLUT4 expression in skeletal muscle.