Abstract
Macrophage uptake of oxidized low-density lipoprotein (oxLDL) is thought to play a central role in foam cell formation and the pathogenesis of atherosclerosis. We demonstrate here that oxLDL activates PPARgamma-dependent transcription through a novel signaling pathway involving scavenger receptor-mediated particle uptake. Moreover, we identify two of the major oxidized lipid components of oxLDL, 9-HODE and 13-HODE, as endogenous activators and ligands of PPARgamma. Our data suggest that the biologic effects of oxLDL are coordinated by two sets of receptors, one on the cell surface, which binds and internalizes the particle, and one in the nucleus, which is transcriptionally activated by its component lipids. These results suggest that PPARgamma may be a key regulator of foam cell gene expression.
MeSH Terms
Animals
CD36 Antigens/analysis,genetics
Cell Differentiation
Cells, Cultured
Dimerization
Fatty Acids, Unsaturated/pharmacology
Humans
Ligands
Linoleic Acids/metabolism,pharmacology
Linoleic Acids, Conjugated
Lipopolysaccharide Receptors/analysis
Lipoproteins, LDL/metabolism,pharmacology
Macrophages/metabolism
Membrane Proteins
Monocytes/cytology,metabolism
Oxidation-Reduction
Prostaglandin D2/analogs & derivatives,pharmacology
Receptors, Cytoplasmic and Nuclear/chemistry,genetics,metabolism
Receptors, Immunologic/genetics
Receptors, Lipoprotein
Receptors, Retinoic Acid/chemistry,metabolism
Receptors, Scavenger
Recombinant Fusion Proteins
Retinoid X Receptors
Scavenger Receptors, Class B
Signal Transduction/physiology
Transcription Factors/chemistry,genetics,metabolism
Transcriptional Activation/physiology
Chemicals
15-deoxy-delta(12,14)-prostaglandin J2
CD36 Antigens
Fatty Acids, Unsaturated
Ligands
Linoleic Acids
Linoleic Acids, Conjugated
Lipopolysaccharide Receptors
Lipoproteins, LDL
Membrane Proteins
Receptors, Cytoplasmic and Nuclear
Receptors, Immunologic
Receptors, Lipoprotein
Receptors, Retinoic Acid
Receptors, Scavenger
Recombinant Fusion Proteins
Retinoid X Receptors
Scarb1 protein, mouse
Scavenger Receptors, Class B
Transcription Factors
oxidized low density lipoprotein
9-hydroxy-10,12-octadecadienoic acid
13-hydroxy-9,11-octadecadienoic acid
Prostaglandin D2
Authors & Affiliations
5 authors, click to expand affiliations / ORCID
Nagy L
The Salk Institute of Biological Studies, Howard Hughes Medical Institute, La Jolla, California 92037, USA.
Tontonoz P
Alvarez J G
Chen H
Evans R M