TGR5-Mediated Bile Acid Sensing Controls Glucose Homeostasis

Institut de Génétique et Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, 67404 Illkirch, France.
Cell metabolism (Impact Factor: 16.75). 10/2009; 10(3):167-77. DOI: 10.1016/j.cmet.2009.08.001
Source: PubMed

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.

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