[New oxidized LDL receptors and their functions in atherogenesis].
Oxidized low density lipoprotein (Ox-LDL) appears to play key roles in atherosclerotic progression and plaque rupture. Biological effects of Ox-LDL on vascular cells may, at least in part, be mediated by cell surface receptors for Ox-LDL. Lectin-like oxidized LDL receptor (LOX)-1 and scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX) are type II and I membrane glycoprtoeins, respectively, both of which can act as cell-surface endocytosis receptors for atherogenic oxidized LDL (Ox-LDL). LOX-1 expression can dynamically be induced by proinflammatory stimuli, and is detectable in cultured macrophages and activated vascular smooth muscle cells (VSMC), in addition to endothelial cells. LOX-1-dependent uptake of Ox-LDL induced apoptosis of cultured VSMC. In vivo, endothelial cells that cover early atherosclerotic lesions, and intimal macrophages and VSMC in advanced atherosclerotic plaques dominantly express LOX-1. LOX-1 expressed on the cellsurface can be cleaved, in part, and released as soluble molecules, suggesting the diagnostic significance of plasma soluble LOX-1 levels. SR-PSOX appeared to be identical to CXCL16, a novel membrane-anchored chemokine directed to CXCR6-positive lymphocytes, suggesting another role of SR-PSOX as T-cell chemoattractant. In contrast to LOX-1 expressed by a variety of cell types. SR-PSOX expression appeared relatively confined to macrophages in atherogenesis. Taken together, LOX-1 and SR-PSOX may play important roles in atherogenesis and athrosclerotic plaque rupture.
Kume
Noriaki
N
Department of Geriatric Medicine, Graduate School of Medicine, Kyoto University.
D017209:Apoptosis; D001161:Arteriosclerosis / Q000209:etiology* / Q000473:pathology; D000075743:Chemokine CXCL16; D019743:Chemokines, CXC; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D008565:Membrane Proteins; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D011971:Receptors, Immunologic / Q000502:physiology*; D011973:Receptors, LDL / Q000502:physiology*; D051131:Receptors, Oxidized LDL; D051116:Receptors, Scavenger; D051127:Scavenger Receptors, Class E
C423727:CXCL16 protein, human; D000075743:Chemokine CXCL16; D019743:Chemokines, CXC; D008565:Membrane Proteins; C495137:OLR1 protein, human; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D051131:Receptors, Oxidized LDL; D051116:Receptors, Scavenger; D051127:Scavenger Receptors, Class E