The farnesoid X receptor modulates hepatic carbohydrate metabolism during the fasting-refeeding transition

J Biol Chem. 2005 Aug 19;280(33):29971-9. doi: 10.1074/jbc.M501931200. Epub 2005 May 16.

Abstract

The liver plays a central role in the control of blood glucose homeostasis by maintaining a balance between glucose production and utilization. The farnesoid X receptor (FXR) is a bile acid-activated nuclear receptor. Hepatic FXR expression is regulated by glucose and insulin. Here we identify a role for FXR in the control of hepatic carbohydrate metabolism. When submitted to a controlled fasting-refeeding schedule, FXR(-/-) mice displayed an accelerated response to high carbohydrate refeeding with an accelerated induction of glycolytic and lipogenic genes and a more pronounced repression of gluconeogenic genes. Plasma insulin and glucose levels were lower in FXR(-/-) mice upon refeeding the high-carbohydrate diet. These alterations were paralleled by decreased hepatic glycogen content. Hepatic insulin sensitivity was unchanged in FXR(-/-) mice. Treatment of isolated primary hepatocytes with a synthetic FXR agonist attenuated glucose-induced mRNA expression as well as promoter activity of L-type pyruvate kinase, acetyl-CoA carboxylase 1, and Spot14. Moreover, activated FXR interfered negatively with the carbohydrate response elements regions. These results identify a novel role for FXR as a modulator of hepatic carbohydrate metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbohydrate Metabolism*
  • DNA-Binding Proteins / physiology*
  • Fasting / physiology*
  • Female
  • Gene Expression Profiling
  • Gluconeogenesis
  • Glycolysis
  • Hepatocytes / metabolism
  • Lipids / biosynthesis
  • Liver / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Promoter Regions, Genetic
  • Receptors, Cytoplasmic and Nuclear
  • Signal Transduction
  • Transcription Factors / genetics
  • Transcription Factors / physiology*

Substances

  • DNA-Binding Proteins
  • Lipids
  • Receptors, Cytoplasmic and Nuclear
  • Transcription Factors
  • farnesoid X-activated receptor