The Bile Acid Receptor FXR Is a Modulator of Intestinal Innate Immunity

The farnesoid X receptor (FXR) is a bile acid-regulated nuclear receptor expressed in enterohepatic tissues. In this study we investigated whether FXR is expressed by cells of innate immunity and regulates inflammation in animal models of colitis. Acute (7 days) and chronic (8 wk) colitis were induced in wild-type and FXR(-/-) mice by intrarectal administration of trinitrobenzensulfonic acid or by 7-day administration of 5% dextran sulfate in drinking water. The results of this experiment demonstrate that FXR is expressed by and exerts counterregulatory effects on cells of innate immunity. Exposure of LPS-activated macrophages to 6-ethyl chenodeoxycholic acid (6E-CDCA; INT-747) a synthetic FXR ligand, results…