Table 1.
Functions of Hepatic FXR (hFXR) and Intestinal FXR (iFXR)
| hFXR | iFXR | |
|---|---|---|
| Hepatic bile acid synthesis | SHP-dependent reduction in CYP7A1 | Reduction via FGF15/19-FGFR4-CYP7A1 axis |
| Bile acid transporters | ↑ Export (BSEP) | ↑ Export (OSTα/β) |
| ↓ Import (NTCP) | ↓ Import (ASBT) | |
| Lipid metabolism | ↑ Lipolysis | ↑ Ceramide synthesis |
| ↓ Lipogenesis | Promotes adipose tissue browning | |
| Glucose homeostasis | ↑ Glucose tolerance and insulin sensitivity | Controversial — both activation and inhibition may ↑ glucose tolerance and insulin sensitivity and ↓ hepatic gluconeogenesis |