The pivotal role of a novel free fatty acid receptor GPR164 in the intestinal barrier function

Abstract

GPR164 is a novel free fatty acid receptor, activated by both short-chain fatty acids and medium-chain fatty acids, and expressed throughout the gastrointestinal tract. Although GPR164 is reported to be involved in the release of gut hormones, the physiological functions of this receptor in the maintenance of intestinal homeostasis remain unclear. In this study, we explored the role of GPR164 in regulating intestinal barrier function using mice lacking Gpr164 gene (Gpr164-/-). A loss-of-function mutation in GPR164 promoted cell proliferation and disrupted the intestinal barrier function in both Caco-2 cell line and mice. Genome-wide RNA-seq analysis revealed that GPR164 deletion caused aberrant wnt/{beta}-catenin signaling, and the intraperitoneal injection of wnt/{beta}-catenin inhibitor ameliorated a series of abnormalities of Gpr164-/- mice. Gpr164-/- mice also exhibited gut microbial dysbiosis and severe inflammation, indicating that deletion of Gpr164 causes similar pathologies observed in patients with inflammation bowel disease (IBD). Thus, our findings uncover the pivotal role of GPR164 in the maintenance of intestinal barrier function, providing an attractive clinical target for IBD.