Open AccessCoupling of mitochondrial function and skeletal muscle fiber type by a miR‐499/Fnip1/ AMPK circuit
Author(s) -
Liu Jing,
Liang Xijun,
Zhou Danxia,
Lai Ling,
Xiao Liwei,
Liu Lin,
Fu Tingting,
Kong Yan,
Zhou Qian,
Vega Rick B,
Zhu MinSheng,
Kelly Daniel P,
Gao Xiang,
Gan Zhenji
Publication year - 2016
Publication title -
embo molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.923
H-Index - 107
eISSN - 1757-4684
pISSN - 1757-4676
DOI - 10.15252/emmm.201606372
Subject(s) - china , key (lock) , pharmaceutical sciences , chinese academy of sciences , library science , engineering , microbiology and biotechnology , biology , political science , computer science , pharmacology , ecology , law
Upon adaption of skeletal muscle to physiological and pathophysiological stimuli, muscle fiber type and mitochondrial function are coordinately regulated. Recent studies have identified pathways involved in control of contractile proteins of oxidative‐type fibers. However, the mechanism for coupling of mitochondrial function to the muscle contractile machinery during fiber type transition remains unknown. Here, we show that the expression of the genes encoding type I myosins, Myh7 / Myh7b and their intronic miR‐208b/miR‐499, parallels mitochondrial function during fiber type transitions. Using in vivo approaches in mice, we found that miR‐499 drives a PGC ‐1α‐dependent mitochondrial oxidative metabolism program to match shifts in slow‐twitch muscle fiber composition. Mechanistically, miR‐499 directly targets Fnip1 , an AMP ‐activated protein kinase ( AMPK )‐interacting protein that negatively regulates AMPK , a known activator of PGC ‐1α. Inhibition of Fnip1 reactivated AMPK / PGC ‐1α signaling and mitochondrial function in myocytes. Restoration of the expression of miR‐499 in the mdx mouse model of Duchenne muscular dystrophy ( DMD ) reduced the severity of DMD . Thus, we have identified a miR‐499/Fnip1/ AMPK circuit that can serve as a mechanism to couple muscle fiber type and mitochondrial function.