LOX-1, the receptor for oxidized low-density lipoprotein identified from endothelial cells: implications in endothelial dysfunction and atherosclerosis

Pharmacol Ther. 2002 Jul;95(1):89-100. doi: 10.1016/s0163-7258(02)00236-x.

Abstract

Lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1) was initially identified as the major receptor for oxidized LDL (OxLDL) in endothelial cells. Its inducible expression in macrophages and smooth muscle cell was also observed. LOX-1 is a Type II membrane protein with a typical C-type lectin structure at the extracellular C-terminus. It can be cleaved by an unknown protease at the extracellular juxtamembrane region to release the soluble form of LOX-1. The extracellular domains of LOX-1 are post-translationally modified by N-linked glycosylation. Mutagenesis studies revealed that the lectin domain of LOX-1 is the functional domain that recognizes the LOX-1 ligand. The C-terminal end residues and several conserved positively charged residues spanning the lectin domain are essential for OxLDL binding. LOX-1 activation by OxLDL causes endothelial changes that are characterized by activation of nuclear factor-kappaB through an increased reactive oxygen species, subsequent induction of adhesion molecules, and endothelial apoptosis. In vitro, expression of LOX-1 is induced by many inflammatory cytokines, oxidative stress, hemodynamic stimuli, and OxLDL. In vivo, the expression is enhanced in pro-atherogenic settings including, hypertension, hyperlipidemia, and diabetes, and, indeed, is accumulated in the atherosclerotic and glomerulosclerotic lesions. LOX-1 binds multiple classes of ligands that are implicated in the pathogenesis of atherosclerosis. Besides OxLDL, LOX-1 can recognize apoptotic/aged cells, activated platelets, and bacteria, implying versatile physiological functions. Taken together, all these findings support the possible contribution of LOX-1 to the pathogenesis of vascular disorders, particularly atherosclerosis. Development of antagonists for LOX-1 might be a good therapeutic approach to vascular diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arteriosclerosis / metabolism*
  • Cells, Cultured
  • Endothelium, Vascular / metabolism*
  • Humans
  • Lipoproteins, LDL / metabolism*
  • Molecular Sequence Data
  • Myocytes, Smooth Muscle / metabolism
  • Receptors, LDL / chemistry
  • Receptors, LDL / genetics
  • Receptors, LDL / metabolism*
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • Sequence Alignment

Substances

  • Lipoproteins, LDL
  • OLR1 protein, human
  • Receptors, LDL
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • oxidized low density lipoprotein