CHYLOMICRONS INDUCE E-SELECTIN AND VCAM-1 EXPRESSION IN ENDOTHELIAL-CELLS

An increased adherence of leukocytes to the vascular endothelium appea rs to be a crucial event in the development of atherosclerosis. The ro le of endothelial cell adhesion molecules is gaining increasingly inte rest in this context. Several studies show an influence of lipoprotein s, especially low-density-lipoproteins on adhesion molecule stimulatio n. The aim of our study was to analyze the atherogenic potential of po stprandially elevated serum triglyceride levels by investigating the i mpact of postprandial lipoproteins (chylomicrons (CH, isolated 4h afte r a standard oral lipid load)) on the expression of E-selectin (endoth elial leukocyte adhesion molecule-1, ELAM-1) and VCAM-1 (vascular cell adhesion molecule-1). In addition we used chylomicrons that had been incubated with lipoprotein lipase (50U/ml) for 3h (CH-LPL). The endoto xin lipopolysaccharide (LPS) served as positive control for adhesion m olecule stimulation. Human umbilical vein endothelial cells (HUVEC) we re incubated with the samples for 4h and expression of E-Selectin and VCAM-1 was determined by ELISA. The expression of E-selectin was induc ed by LPS (530+/-64% compared to the basal activity (=100%)) and by CH (342+/-94%); CH-LPL had no effect on E-Selectin expression. VCAM-1 ex pression was stimulated by LPS (395+/-221%) and similarly by CH-LPL (3 22+/-136%) but considerably stronger by CH (1245+/-324).