Expression of intercellular adhesion molecule-1 in human coronary endothelial and smooth muscle cells after stimulation with tumor necrosis factor-alpha

Background The intercellular adhesion molecule-1 (ICAM-1) is one of several human cell adhesion molecules that play a critical role in the early stage s of postangioplasty restenosis, In this study, the in-vitro expression of ICAM-1 in human coronary endothelial cells and human coronary smooth muscle cells (SMC) after stimulation with tumor necrosis factor-alpha (TNF-alpha) was investigated. Methods and results SMC were isolated from the media of normal human corona ry arteries (n = 26) up to 10 h post mortem (HCMSMC) and from human atheros clerotic coronary arteries (HCPSMC) that were extracted by thrombendarterec tomy (n = 25), Endothelial cells of human coronary arteries (HCAEC) were pu rchased from Clonetics (Cell System, Remagen, Germany), and endothelial cel ls from human umbilical cord veins (HUVEC) were isolated after vaginal deli very. For investigations of the effect of TNF-alpha (2.5, 5, 10, and 20 ng/ ml) on the proliferative activity of HUVEC, HCAEC, HCPSMC, and HCMSMC, seru m-free media was used. After 24 h cell number and cell size distribution we re measured in a cell analyzer system, The proliferation of HCPSMC and HCMS MC was increased by TNF-alpha; however, significant differences compared wi th controls were not reached. The proliferation of HUVEC and HCAEC was sign ificantly reduced by TNF-alpha. For investigations of the effect of TNF-alp ha (2.5, 5, 10, and 20 ng/ml) on the surface expression of ICAM-1, monoclon al anti-ICAM-1 antibodies (84H10) were used. The expression of ICAM-1 was a nalyzed using an immunofluorescence microscope. For flow cytometry analysis , 5 x 10(3) cells (100% gated) were analyzed using a fluorescence-activated cell sorter. In control cultures with no stimulation, the expression of IC AM-1 was positive in HCAEC, HCPSMC, HCMSMC, and HUVEC. TNF-alpha stimulated the expression of ICAM-1 in a time- and dose-dependent manner. After maxim al stimulation with TNF-alpha (20 ng/ml for 24 h), the expression of ICAM-1 was stronger in HCMSMC than in HCPSMC. Conclusions These results suggest that the cytokine TNF-alpha regulates the expression of ICAM-1 in both human coronary endothelial cells and SMC, and could therefore play an important role in the pathophysiology of inflammat ory and immune processes in restenosis after angioplasty. Coronary Artery D is 9:737-745 (C) 1998 Lippincott Williams & Wilkins.