Skeletal muscle adaptation to fatty acid depends on coordinated actions of the PPARs and PGC1 alpha: implications for metabolic disease.

Journal Article (Review)

Dyslipidemia and intramuscular accumulation of fatty acid metabolites are increasingly recognized as core features of obesity and type 2 diabetes. Emerging evidence suggests that normal physiological adaptations to a heavy lipid load depend on the coordinated actions of broad transcriptional regulators such as the peroxisome proliferator activated receptors (PPARs) and PPAR gamma coactivator 1 alpha (PGC1 alpha). The application of transcriptomics and targeted metabolic profiling tools based on mass spectrometry has led to our finding that lipid-induced insulin resistance is a condition in which upregulation of PPAR-targeted genes and high rates of beta-oxidation are not supported by a commensurate upregulation of tricarboxylic acid (TCA) cycle activity. In contrast, exercise training enhances mitochondrial performance, favoring tighter coupling between beta-oxidation and the TCA cycle, and concomitantly restores insulin sensitivity in animals fed a chronic high-fat diet. The exercise-activated transcriptional coactivator, PGC1 alpha, plays a key role in coordinating metabolic flux through these 2 intersecting metabolic pathways, and its suppression by overfeeding may contribute to diet-induced mitochondrial dysfunction. Our emerging model predicts that muscle insulin resistance arises from a mitochondrial disconnect between beta-oxidation and TCA cycle activity. Understanding of this "disconnect" and its molecular basis may lead to new therapeutic approaches to combatting metabolic disease.

Full Text

Duke Authors

Cited Authors

  • Muoio, DM; Koves, TR

Published Date

  • October 2007

Published In

Volume / Issue

  • 32 / 5

Start / End Page

  • 874 - 883

PubMed ID

  • 18059612

International Standard Serial Number (ISSN)

  • 1715-5312

Digital Object Identifier (DOI)

  • 10.1139/H07-083

Language

  • eng

Conference Location

  • Canada