Platelets induce alterations of chemotactic and adhesive properties of endothelial cells mediated through an interleukin-1-dependent mechanism. Implications for atherogenesis

Abstract Platelets and alterations of chemotactic and adhesive properties of endothelium play an important role in the pathophysiology of atherosclerosis. We investigated the effect of platelets on secretion of monocyte chemotactic protein-1 (MCP-1) and on surface expression of intercellular adhesion molecule-1 (ICAM-1) of cultured endothelium. Pretreatment of cultured monolayers of endothelial cells with α-thrombin-activated platelets significantly enhanced secretion of MCP-1 and ICAM-1 surface expression ( P v β 3 ) on the luminal aspect of endothelial monolayers and promoted α v β 3 -mediated platelet/endothelium adhesion that could be inhibited by the antiadhesive peptides GRGDSP and c(RGDfV). We conclude that activated platelets induce significant changes in chemotactic (secretion of MCP-1) and adhesive (surface expression of ICAM-1 and α v β 3 ) properties of cultured endothelium. These findings imply a potential pathophysiological mechanism of platelets in an early stage of atherogenesis.