Role of PPARα and LXRs in macrophage cholesterol trafficking
PPARα and LXR activation stimulates the post-lysosomal mobilization of cholesterol by regulating NPC1 and NPC2 expression. This leads to an enrichment of cholesterol in the plasma membrane and a redistribution of cholesterol in the outer cell-surface domains, where it is more available for efflux through the ABCA1 pathway. As a consequence, PPARα and LXR activation decreases the availability of cholesterol for ACAT1 and thus the cellular amount of CEs.