FXR in liver physiology: Multiple faces to regulate liver metabolism

The liver is the central metabolic hub which coordinates nutritional inputs and metabolic outputs. Food intake releases bile acids which can be sensed by the bile acid receptor FXR in the liver and the intestine. Hepatic and intestinal FXR coordinately regulate postprandial nutrient disposal in a network of interacting metabolic nuclear receptors. In this review we summarize and update the classical roles of FXR as a central integrator of the feeding state response, which orchestrates the metabolic processing of carbohydrates, lipids, proteins and bile acids. We also discuss more recent and less well studied FXR effects on amino acid, protein metabolism, autophagic turnover and inflammation. In addition, we summarize the recent understanding of how FXR signaling is affected by posttranslational modifications and by different FXR isoforms. These modifications and variations in FXR signaling might be considered when FXR is targeted pharmaceutically in clinical applications.

Automated summary

The liver serves as a central metabolic hub that coordinates nutritional inputs and metabolic outputs. FXR in the liver and intestine plays a crucial role in regulating postprandial nutrient disposal. Aside from classical roles, FXR also has effects on amino acid, protein metabolism, autophagic turnover, and inflammation, which are less studied. Additionally, understanding of how FXR signaling is affected by posttranslational modifications and different isoforms is important for potential pharmaceutical targeting in clinical applications.