The adhesion molecule P-selectin (CD62P) is of interest because of its role in modulating interactions between blood cells and the endothelium, and also because of the possible use of the soluble form as a plasma predictor of adverse cardiovascular events. Although present on the external cell surface of both activated endothelium and activated platelets, it now seems clear that most, if not all, of the measured plasma P-selectin is of platelet origin. P-selectin is partially responsible for the adhesion of certain leukocytes and platelets to the endothelium. Animal models have also shown the important role of P-selectin in the process of atherogenesis. For example, increased P-selectin expression has been demonstrated on active atherosclerotic plaques; in contrast, fibrotic inactive plaques lack P-selectin expression, and animals lacking P-selectin have a decreased tendency to form atherosclerotic plaques. Increased levels of soluble P-selectin in the plasma have also been demonstrated in a variety of cardiovascular disorders, including coronary artery disease, hypertension and atrial fibrillation, with some relationship to prognosis. The objective of this review is to provide an overview of the current literature on this molecule and thus present a concise view of its potential in dissecting the pathophysiology of atherosclerosis. In doing so we shall focus primarily on human biology but will note a small number of excellent lessons provided by non-human work.
- platelet activation