The induction of human CL-P1 expression in hypoxia/reoxygenation culture condition and rat CL-P1 after ischemic/reperfusion treatment.

ABSTRACT

BACKGROUND: Oxidative stress-induced endothelial dysfunction and oxidized low-density lipoprotein (LDL) might play a key role in the pathogenesis of atherosclerosis. We recently identified a vascular endothelial scavenger receptor, collectin placenta 1 (CL-P1), which acts as a receptor for oxidized LDL as well as for microbes. METHODS: We demonstrate how hypoxic and oxidative stress induced CL-P1 expression and compared their effects with the expression of lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1), an endothelial scavenger receptor expressed by oxidative stress. RESULTS: Hypoxia/reoxygenation induced CL-P1 mRNA and protein expression in human umbilical vein endothelial cells (HUVECs). The expression of LOX-1 mRNA in these cells peaked slightly at 24 h, while the expression of CL-P1 had an onset at 72 h and was sustained for 120 h after reoxygenation. Furthermore, the exposure of rat carotid artery endothelium to ischemia/reperfusion increased the maximal CL-P1 mRNA expression at 72 h and expression of its protein peaked at 7 days after this treatment. We demonstrate that CL-P1 up-regulation is induced in vitro and in vivo by oxidative stress. GENERAL SIGNIFICANCE: The inducible expression of CL-P1 by oxidative stress might play a crucial role in endothelial dysfunction or chronic activation leading to the pathogenesis of atherosclerosis.