PPARγ coactivator-1α contributes to exercise-induced regulation of intramuscular lipid droplet programming in mice and humans.

Journal Article

Intramuscular accumulation of triacylglycerol, in the form of lipid droplets (LD), has gained widespread attention as a hallmark of metabolic disease and insulin resistance. Paradoxically, LDs also amass in muscles of highly trained endurance athletes who are exquisitely insulin sensitive. Understanding the molecular mechanisms that mediate the expansion and appropriate metabolic control of LDs in the context of habitual physical activity could lead to new therapeutic opportunities. Herein, we show that acute exercise elicits robust upregulation of a broad program of genes involved in regulating LD assembly, morphology, localization, and mobilization. Prominent among these was perilipin-5, a scaffolding protein that affects the spatial and metabolic interactions between LD and their surrounding mitochondrial reticulum. Studies in transgenic mice and primary human skeletal myocytes established a key role for the exercise-responsive transcriptional coactivator PGC-1α in coordinating intramuscular LD programming with mitochondrial remodeling. Moreover, translational studies comparing physically active versus inactive humans identified a remarkably strong association between expression of intramuscular LD genes and enhanced insulin action in exercise-trained subjects. These results reveal an intimate molecular connection between intramuscular LD biology and mitochondrial metabolism that could prove relevant to the etiology and treatment of insulin resistance and other disorders of lipid imbalance.

Full Text

Duke Authors

Cited Authors

  • Koves, TR; Sparks, LM; Kovalik, JP; Mosedale, M; Arumugam, R; DeBalsi, KL; Everingham, K; Thorne, L; Phielix, E; Meex, RC; Kien, CL; Hesselink, MKC; Schrauwen, P; Muoio, DM

Published Date

  • February 2013

Published In

Volume / Issue

  • 54 / 2

Start / End Page

  • 522 - 534

PubMed ID

  • 23175776

Electronic International Standard Serial Number (EISSN)

  • 1539-7262

Digital Object Identifier (DOI)

  • 10.1194/jlr.P028910

Language

  • eng

Conference Location

  • United States