[Effect of lysophosphatidylcholine on endothelial cell surface expression of adhesion molecules]

Extensive monocyte recruitment is an early phenomenon associated with the development of atherosclerotic lesion, in which adhesion molecules expressed by endothelial cell play an active role. In this study we examined the effects of Lysophosphatidylcholine(Lyso-PC), a major phospholipid component of atherogenic lipoproteins, on the expression of adhesion molecules for monocytes, such as intercellular adhesion molecule-1(I-CAM-1), endothelial-leukocyte adhesion molecule-1(E-selectin) and vascular cell adhesion molecule-1(VCAM-1), in cultured human umbilical vein endothelial cells(HUVECs). After treating HUVECs with different concentration Lyso-PC at different times, the expression of adhesion molecules on the surface of HUVECs induced by Lyso-PC were analyzed using flow cytometry. The results showed that compared with control group, the surface expression of ICAM-1 and VCAM-1 was increased on HUVECs treated with Lyso-PC. ICAM-1 and VCAM-1 expression was maximally induced 1 h after stimulated with 50 micrograms/mg Lyso-PC, compared to basal values. At the 3 h after stimulation, ICAM-1 dropped to basal level while VCAM-1 dropped below to basal level. The effects of Lyso-PC on E-selection expression were negligible with in 3 h. However, at the 3 h of treatment with 50 micrograms/ml, the E-selectin expression on HUVECs began to be up-regulated significantly. We conclude that in addition to its monocyte chemoatractant activity, Lyso-PC can selectively induce ICAM-1 and VCAM-1 expression on the surface of HUVECs. Lyso-PC may play an important role in monocyte recruitment into athersclerotic lesions.