Kinetics of platelet P-selectin mobilization: Concurrent surface expression and release induced by thrombin or PMA, and inhibition by the NO Donor SNAP
| Autor: | Uppugunduri Srinivas, Per A Whiss, Rolf G. G. Andersson |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Blood Platelets
Male P-selectin Endothelium Chemistry Cell adhesion molecule Penicillamine Thrombin Enzyme-Linked Immunosorbent Assay General Medicine Platelet Activation P-Selectin medicine.anatomical_structure Biochemistry Biophysics medicine Humans Tetradecanoylphorbol Acetate Platelet Platelet activation Fluorescent Antibody Technique Indirect Protein kinase C Intracellular medicine.drug |
| Zdroj: | Cell Adhesion and Communication. 6:289-300 |
| ISSN: | 1029-2314 |
| DOI: | 10.3109/15419069809010788 |
| Popis: | 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 (0.1-1.0 microM) 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. |
| Databáze: | OpenAIRE |
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