The formation of foam cells from macrophages in the arterial wall is characterized by dramatic changes in lipid metabolism, including increased expression of scavenger receptors and the uptake of oxidized low-density lipoprotein (oxLDL). We demonstrate here that the nuclear receptor PPARγ is induced in human monocytes following exposure to oxLDL and is expressed at high levels in the foam cells of atherosclerotic lesions. Ligand activation of the PPARγ:RXRα heteredimer in myelomonocytic cell lines induces changes characteristic of monocytic differentiation and promotes uptake of oxLDL through transcriptional induction of the scavenger receptor CD36. These results reveal a novel signaling pathway controlling differentiation and lipid metabolism in monocytic cells, and suggest that endogenous PPARγ ligands may be important regulators of gene expression during atherogenesis.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)