TGR5-mediated bile acid sensing controls glucose homeostasis

Cell Metab. 2009 Sep;10(3):167-77. doi: 10.1016/j.cmet.2009.08.001.

Abstract

TGR5 is a G protein-coupled receptor expressed in brown adipose tissue and muscle, where its activation by bile acids triggers an increase in energy expenditure and attenuates diet-induced obesity. Using a combination of pharmacological and genetic gain- and loss-of-function studies in vivo, we show here that TGR5 signaling induces intestinal glucagon-like peptide-1 (GLP-1) release, leading to improved liver and pancreatic function and enhanced glucose tolerance in obese mice. In addition, we show that the induction of GLP-1 release in enteroendocrine cells by 6alpha-ethyl-23(S)-methyl-cholic acid (EMCA, INT-777), a specific TGR5 agonist, is linked to an increase of the intracellular ATP/ADP ratio and a subsequent rise in intracellular calcium mobilization. Altogether, these data show that the TGR5 signaling pathway is critical in regulating intestinal GLP-1 secretion in vivo, and suggest that pharmacological targeting of TGR5 may constitute a promising incretin-based strategy for the treatment of diabesity and associated metabolic disorders.

Publication types

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

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Bile Acids and Salts / metabolism*
  • CHO Cells
  • Calcium / metabolism
  • Cell Line
  • Cholic Acids / chemistry
  • Cholic Acids / pharmacology*
  • Cricetinae
  • Cricetulus
  • Enteroendocrine Cells / metabolism
  • Glucagon-Like Peptide 1 / metabolism
  • Glucose / metabolism*
  • Homeostasis
  • Humans
  • Insulin / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Obese
  • Oxidative Phosphorylation
  • Receptors, G-Protein-Coupled / agonists
  • Receptors, G-Protein-Coupled / deficiency
  • Receptors, G-Protein-Coupled / metabolism*
  • Signal Transduction

Substances

  • 6alpha-ethyl-23(S)-methylcholic acid
  • Bile Acids and Salts
  • Cholic Acids
  • GPBAR1 protein, human
  • Gpbar1 protein, mouse
  • Insulin
  • Receptors, G-Protein-Coupled
  • Glucagon-Like Peptide 1
  • Adenosine Triphosphate
  • Glucose
  • Calcium