Kinetics of platelet P-selectin mobilization: Concurrent surface expression and release induced by thrombin or PMA, and inhibition by the NO Donor SNAP
1998 (English)In: Cell Communication & Adhesion, ISSN 1541-9061, E-ISSN 1543-5180, Vol. 6, no 4, 289-300 p.Article in journal (Refereed) Published
Activated platelets and endothelium surface express the cell adhesion molecule P-selectin (CD62P), which plays an important role in mediating interactions with leukocytes. Increased levels of a functional soluble form of P-selectin (sP-selectin) have been reported in several pathological states but it is not clear whether this circulating sP-selectin originates from platelets and/or endothelial cells. Here we describe the concurrent kinetics of intracellular storage, surface expression and release of platelet P-selectin induced by thrombin or the protein kinase C activator PMA. Platelet activation with submaximal concentrations of thrombin (0.1 U/ml) resulted in a rapid decrease of intracellular P-selectin. This decrease of intracellular P-selectin concurred with a gradual increase of surface expression and an initial increase of sP-selectin. Our results indicate that intracellular stores of P-selectin were only partly mobilized upon activation with submaximal concentrations of thrombin. A high concentration of thrombin (1.0 U/ml) induced a rapid and nearly total decrease of intracellular stores and a more pronounced, but transient, increase of surface expression. The release of P-selectin was fast and occurred during the initial activation phase. The NO donor SNAP inhibited both surface expression and release of platelet P-selectin in a similar manner. PMA (0.1–1.01 µM) mediated a more slow, gradual and sustained surface expression and release of P-selectin than thrombin. Thus, surface expression and release of platelet P-selectin show different kinetics depending on the mode of activation.
Place, publisher, year, edition, pages
1998. Vol. 6, no 4, 289-300 p.
P-selectin mobilization, kinetics, human platelets, thrombin, phorbol ester, nitric oxide
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-79742DOI: 10.3109/15419069809010788OAI: oai:DiVA.org:liu-79742DiVA: diva2:544113