Figure 1.
Summary of the impact of FXR on lipid metabolism. FXR activation by bile acids induces the expression of sterol regulatory element–binding protein-1c (SREBP1c) in mice and peroxisome proliferator–activated receptor-α (PPARα) in humans, which both will modulate triglyceride (TG) production. However, the increase of apoC-II, VLDL receptor, and syndecan 1 gene expression together with the repression of apoC-III will increase LPL activity and therefore triglyceride clearance. FXR also represses apoAI expression and therefore HDL levels but also enhances the remodeling of HDL particles by induction of phospholipid transfer protein (PLTP) and perhaps cholesteryl ester transfer protein (CETP) expression. Used with permission from Claudel et al. (10).