IMP2 Increases Mouse Skeletal Muscle Mass and Voluntary Activity by Enhancing Autocrine Insulin-Like Growth Factor 2 Production and Optimizing Muscle Metabolism.

ABSTRACT: Insulin-like growth factor 2 (IGF2) mRNA binding protein 2 (IMP2) was selectively deleted from adult mouse muscle; two phenotypes were observed: decreased accrual of skeletal muscle mass after weaning and reduced wheel-running activity but normal forced treadmill performance. Reduced wheel running occurs when mice are fed a high-fat diet but is normalized when mice consume standard chow. The two phenotypes are due to altered output from different IMP2 client mRNAs. The reduced fiber size of IMP2-deficient muscle is attributable, in part, to diminished autocrine Igf2 production; basal tyrosine phosphorylation of the insulin and IGF1 receptors is diminished, and Akt1 activation is selectively reduced. Gsk3α is disinhibited, and S536-phosphorylated ε subunit of eukaryotic initiation factor 2B

SUBMITTER: Regue L 

PROVIDER: S-EPMC6425142 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature