Hepatic expression of malonyl-CoA decarboxylase reverses muscle, liver and whole-animal insulin resistance.


Journal Article

Lipid infusion or ingestion of a high-fat diet results in insulin resistance, but the mechanism underlying this phenomenon remains unclear. Here we show that, in rats fed a high-fat diet, whole-animal, muscle and liver insulin resistance is ameliorated following hepatic overexpression of malonyl-coenzyme A (CoA) decarboxylase (MCD), an enzyme that affects lipid partitioning. MCD overexpression decreased circulating free fatty acid (FFA) and liver triglyceride content. In skeletal muscle, levels of triglyceride and long-chain acyl-CoA (LC-CoA)-two candidate mediators of insulin resistance-were either increased or unchanged. Metabolic profiling of 36 acylcarnitine species by tandem mass spectrometry revealed a unique decrease in the concentration of one lipid-derived metabolite, beta-OH-butyrate, in muscle of MCD-overexpressing animals. The best explanation for our findings is that hepatic expression of MCD lowered circulating FFA levels, which led to lowering of muscle beta-OH-butyrate levels and improvement of insulin sensitivity.

Full Text

Duke Authors

Cited Authors

  • An, J; Muoio, DM; Shiota, M; Fujimoto, Y; Cline, GW; Shulman, GI; Koves, TR; Stevens, R; Millington, D; Newgard, CB

Published Date

  • March 2004

Published In

Volume / Issue

  • 10 / 3

Start / End Page

  • 268 - 274

PubMed ID

  • 14770177

Pubmed Central ID

  • 14770177

International Standard Serial Number (ISSN)

  • 1078-8956

Digital Object Identifier (DOI)

  • 10.1038/nm995


  • eng

Conference Location

  • United States