Regulation of skeletal muscle lipolysis and oxidative metabolism by the co-lipase CGI-58

J Lipid Res. 2012 May;53(5):839-848. doi: 10.1194/jlr.M019182. Epub 2012 Feb 29.

Abstract

We investigated here the specific role of CGI-58 in the regulation of energy metabolism in skeletal muscle. We first examined CGI-58 protein expression in various muscle types in mice, and next modulated CGI-58 expression during overexpression and knockdown studies in human primary myotubes and evaluated the consequences on oxidative metabolism. We observed a preferential expression of CGI-58 in oxidative muscles in mice consistent with triacylglycerol hydrolase activity. We next showed by pulse-chase that CGI-58 overexpression increased by more than 2-fold the rate of triacylglycerol (TAG) hydrolysis, as well as TAG-derived fatty acid (FA) release and oxidation. Oppositely, CGI-58 silencing reduced TAG hydrolysis and TAG-derived FA release and oxidation (-77%, P < 0.001), whereas it increased glucose oxidation and glycogen synthesis. Interestingly, modulations of CGI-58 expression and FA release are reflected by changes in pyruvate dehydrogenase kinase 4 gene expression. This regulation involves the activation of the peroxisome proliferator activating receptor-δ (PPARδ) by lipolysis products. Altogether, these data reveal that CGI-58 plays a limiting role in the control of oxidative metabolism by modulating FA availability and the expression of PPARδ-target genes, and highlight an important metabolic function of CGI-58 in skeletal muscle.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 1-Acylglycerol-3-Phosphate O-Acyltransferase / deficiency
  • 1-Acylglycerol-3-Phosphate O-Acyltransferase / genetics
  • 1-Acylglycerol-3-Phosphate O-Acyltransferase / metabolism*
  • Adolescent
  • Animals
  • Cells, Cultured
  • Energy Metabolism*
  • Fatty Acids / metabolism
  • Gene Expression Regulation, Enzymologic
  • Gene Knockdown Techniques
  • Glucose / metabolism
  • Humans
  • Hydrolases / metabolism
  • Lipase / metabolism*
  • Lipolysis*
  • Mice
  • Mitochondria / metabolism
  • Muscle Fibers, Skeletal / cytology
  • Muscle Fibers, Skeletal / metabolism
  • Muscle, Skeletal / enzymology
  • Muscle, Skeletal / metabolism*
  • Oxidation-Reduction
  • PPAR delta / metabolism
  • Triglycerides / metabolism
  • Young Adult

Substances

  • Fatty Acids
  • PPAR delta
  • Triglycerides
  • 1-Acylglycerol-3-Phosphate O-Acyltransferase
  • ABHD5 protein, human
  • Hydrolases
  • Lipase
  • Glucose