Lysophosphatidylcholine, a component of atherogenic lipoproteins, induces mononuclear leukocyte adhesion molecules in cultured human and rabbit arterial endothelial cells.

Abstract

Accumulation of monocyte-derived foam cells in focal areas of the arterial intima is one of the key events in early atherogene- sis.We have examined the effect of lysophosphatidylcholine (lyso-PC; lysolecithin), a major phospholipid component of atherogenic lipoproteins, on the expression of adhesion mole- cules for monocytes, such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-i (ICAM-1), in cultured human and rabbit arterial endothelial cells.Cul- tured rabbit aortic endothelial cells treated with lyso-PC showed increased mRNA and cell surface expression of VCAM-1 and ICAM-1, which was associated with increased adhesion of monocytes and monocyte-like cells (THP-1, U937).In cultured human iliac artery endothelial cells, lyso- PC similarly induced both VCAM-1 and ICAM-1, whereas in umbilical vein endothelial cells only ICAM-1 was up-regulated.In all endothelial cells examined, the effect of lyso-PC on E-se- lectin (endothelial-leukocyte adhesion molecule-i) expression was negligible, thus differentiating this stimulus from other endothelial activators, such as interleukin 1, tumor necrosis factor, or lipopolysaccharide.We conclude that lyso-PC can selectively induce VCAM-1 and ICAM-1 in arterial endothelial cells and that this action, in addition to its monocyte chemoat- tractant activity, may play an important role in monocyte re- cruitment into atherosclerotic lesions.(J.Clin.Invest.1992. 90:1138-1144.) Key word: atherosclerosis * intercellular adhe- sion molecule-1 * inflammation * oxidized low density lipopro- tein * vascular cell adhesion molecule-1These studies were presented at the 1991 Annual Meeting ofthe Federa- tion of American Societies for Experiment Biology, Atlanta, GA, 21- 25 April 1991 and have appeared in abstract form ( 1991.