A. Vandestolpe et al., FIBRINOGEN BINDING TO ICAM-1 ON EA.HY-926 ENDOTHELIAL-CELLS IS DEPENDENT ON AN INTACT CYTOSKELETON, Thrombosis and haemostasis, 75(1), 1996, pp. 182-189
Fibrinogen is a ligand for Intercellular Adhesion Molecule-1 (ICAM-1),
and enhances monocyte-endothelial cell interaction by coupling Mac-1
on monocytes to ICAM-1 on endothelial cells. We investigated the role
of the cytoskeleton in fibrinogen binding to the human endothelial cel
l line EA.hy 926 using immunofluorescence techniques. In this cell lin
e TNF alpha induced the simultaneous appearance of stress fibers and o
f ICAM-1, which was clustered predominantly on endothelial cell projec
tions. Incubation of TNF alpha-stimulated endothelial cells with fibri
nogen resulted in binding of fibringen to ICAM-1 on these cell project
ions. Disruption of the cytoskeleton by cytocholasin B abolished fibri
nogen binding. Activation of protein kinase C with 12-O-tetradecanoyl
phorbol-13-acetate resulted in simultaneous loss of both stress fibers
and Fibrinogen binding. These results suggest that a connection betwe
en ICAM-1 and the cytoskeleton results in clustering of ICAM-1 on cell
projections, which is required for fibrinogen binding.