PPARalpha gene expression is up-regulated by LXR and PXR activators in the small intestine.

LXR, PXR, and PPARalpha are members of a nuclear receptor family which regulate the expression of genes involved in lipid metabolism. Here, we show the administration of T0901317 stimulates PPARalpha gene expression in the small intestine but not in the liver of both normal and FXR-null mice. The administration of LXR specific ligand GW3965, or PXR specific ligand PCN has the same effect, indicating that ligand-dependent activation of LXR and PXR, but not FXR, is responsible for the increased gene expression of PPARalpha in the mouse small intestine.