[HTML][HTML] Nutrient-sensing nuclear receptors PPARα and FXR control liver energy balance

GA Preidis, KH Kim, DD Moore - The Journal of clinical …, 2017 - Am Soc Clin Investig
The Journal of clinical investigation, 2017Am Soc Clin Investig
The nuclear receptors PPARα (encoded by NR1C1) and farnesoid X receptor (FXR,
encoded by NR1H4) are activated in the liver in the fasted and fed state, respectively.
PPARα activation induces fatty acid oxidation, while FXR controls bile acid homeostasis, but
both nuclear receptors also regulate numerous other metabolic pathways relevant to liver
energy balance. Here we review evidence that they function coordinately to control key
nutrient pathways, including fatty acid oxidation and gluconeogenesis in the fasted state and …
The nuclear receptors PPARα (encoded by NR1C1) and farnesoid X receptor (FXR, encoded by NR1H4) are activated in the liver in the fasted and fed state, respectively. PPARα activation induces fatty acid oxidation, while FXR controls bile acid homeostasis, but both nuclear receptors also regulate numerous other metabolic pathways relevant to liver energy balance. Here we review evidence that they function coordinately to control key nutrient pathways, including fatty acid oxidation and gluconeogenesis in the fasted state and lipogenesis and glycolysis in the fed state. We have also recently reported that these receptors have mutually antagonistic impacts on autophagy, which is induced by PPARα but suppressed by FXR. Secretion of multiple blood proteins is a major drain on liver energy and nutrient resources, and we present preliminary evidence that the liver secretome may be directly suppressed by PPARα, but induced by FXR. Finally, previous studies demonstrated a striking deficiency in bile acid levels in malnourished mice that is consistent with results in malnourished children. We present evidence that hepatic targets of PPARα and FXR are dysregulated in chronic undernutrition. We conclude that PPARα and FXR function coordinately to integrate liver energy balance.
The Journal of Clinical Investigation