Receptors Involved in the Signaling of Bile Acids
| Receptor | Sites | BA agonist | Functions |
|---|---|---|---|
| FXR | Nuclear receptor, widespread throughout the body, abundant in the liver, intestine, and kidneys | CDCA > DCA > LCA > CA | Regulation of BA synthesis, absorption, and transport |
| Maintenance of metabolic homeostasis | |||
| Modulation of immune system | |||
| TGR5 | Membrane receptor, widespread throughout the body including the intestine, liver, biliary tract, and gallbladder | LCA > DCA > CDCA > CA | Regulation of the intestinal motility and secretion |
| Maintenance of metabolic homeostasis | |||
| Maintenance of intestinal immune homeostasis | |||
| PXR | Nuclear receptor, abundant in the liver and intestine | LCA, only weakly to CDCA, DCA, CA, and conjugated BAs | Detoxication of xenobiotics and LCA |
| Maintenance of intestinal immune homeostasis | |||
| Modulation of BA homeostasis | |||
| VDR | Nuclear receptor, widespread throughout the body, abundant in the intestine | LCA | Detoxication of LCA |
| Modulation of BA synthesis | |||
| Maintenance of bone and calcium homeostasis |
BA, bile acid; FXR, farnesoid X receptor; CDCA, chenodeoxycholic acid; DCA, deoxycholic acid; LCA, lithocholic acid; CA, cholic acid; TGR5, Takeda G protein-coupled receptor 5; PXR, pregnane X receptor; VDR, vitamin D receptor.