C-reactive protein enhances LOX-1 expression in human aortic endothelial cells: relevance of LOX-1 to C-reactive protein-induced endothelial dysfunction

Circ Res. 2004 Oct 29;95(9):877-83. doi: 10.1161/01.RES.0000147309.54227.42. Epub 2004 Oct 7.

Abstract

C-reactive protein (CRP), a characteristic inflammatory marker, is a powerful predictor of cardiovascular events. Recent data suggest that CRP may also promote atherogenesis through inducing endothelial dysfunction. Lectin-like oxidized low-density lipoprotein (oxLDL) receptor-1 (LOX-1) is a newly identified endothelial receptor for oxLDL that plays a pivotal role in oxLDL-induced endothelial dysfunction. Whether CRP may regulate endothelial LOX-1 and induce endothelial dysfunction through this receptor is unknown. In the present study, we studied the in vitro effect of CRP on LOX-1 expression in human aortic endothelial cells (HAECs) and the role of LOX-1 in CRP-induced human monocyte adhesion to endothelium and oxLDL uptake by endothelial cells. Incubation of HAECs with CRP enhanced, in a dose- and time-dependent manner, LOX-1 mRNA and protein levels. Induction of LOX-1 protein was already present at 5 microg/mL CRP and reached a maximum at 25 microg/mL. This effect was reduced by antibodies against CD32/CD64, endothelin-1 (ET-1) and interleukin-6 (IL-6). The extent of stimulation of LOX-1 achieved by CRP was comparable to that elicited by high glucose and IL-6 and remained unchanged in presence of these factors. Finally, CRP increased, through LOX-1, both human monocyte adhesion to endothelial cells and oxLDL uptake by these cells. We conclude that CRP enhances endothelial LOX-1 expression and propose a new mechanism by which CRP may promote endothelial dysfunction, that of inducing LOX-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / pharmacology
  • Aorta / cytology
  • C-Reactive Protein / pharmacology*
  • C-Reactive Protein / physiology
  • Cell Adhesion / drug effects*
  • Cells, Cultured / cytology
  • Cells, Cultured / drug effects
  • E-Selectin / analysis
  • Endothelial Cells / cytology
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / drug effects*
  • Endothelium, Vascular / metabolism
  • Gene Expression Regulation / drug effects
  • Glucose / pharmacology
  • Humans
  • Inflammation / metabolism
  • Intercellular Adhesion Molecule-1 / analysis
  • Interleukin-6 / pharmacology
  • Leukocytes, Mononuclear / drug effects*
  • Lipopolysaccharides / pharmacology
  • Lipoproteins, LDL / metabolism*
  • NF-kappa B / antagonists & inhibitors
  • Nitriles
  • RNA, Messenger / biosynthesis
  • Receptors, LDL / biosynthesis*
  • Receptors, LDL / genetics
  • Receptors, LDL / physiology
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • Sulfones
  • Vascular Cell Adhesion Molecule-1 / analysis

Substances

  • Anti-Infective Agents
  • BAY 11-7085
  • E-Selectin
  • Interleukin-6
  • Lipopolysaccharides
  • Lipoproteins, LDL
  • NF-kappa B
  • Nitriles
  • OLR1 protein, human
  • RNA, Messenger
  • Receptors, LDL
  • Receptors, Oxidized LDL
  • Scavenger Receptors, Class E
  • Sulfones
  • Vascular Cell Adhesion Molecule-1
  • oxidized low density lipoprotein
  • Intercellular Adhesion Molecule-1
  • C-Reactive Protein
  • Glucose