P-Selectin ELISA Kit, Human

On inflammatory and thrombogenic challenges, P-selectin rapidly translocates to the surface of these cells and contributes to the weak adhesion of leukocytes to stimulated endothelial cells and the heterotypic aggregation of activated platelets to leukocytes. A principal leukocyte ligand for P-selectin is P-selectin glycoprotein ligand 1 (PSGL-1), a disulfide bond-linked homodimer, with each subunit having a molecular weight of about 120 kDa. It is expressed on a variety of human leukocytes, including neutrophils, monocytes, certain subsets of T lymphocytes, eosinophils, and basophils. On neutrophils, PSGL-1 localizes to the tips of the microvilli. Several studies of the PSGL-1 knockout mice have demonstrated that PSGL-1 is critically required for neutrophil rolling and migration mediated by P-selectin. PSGL-1 is the best-characterized selectin ligand that has been demonstrated to mediate leukocytes rolling on endothelium and leukocytes recruitment into inflamed tissue in vivo. In addition to its direct role in leukocyte capturing, PSGL-1 also functions as a signal-transducing receptor.² In addition, cross-linking of PSGL-1 by P-selectin also primes leukocytes intracellularly for cytokine and chemoattractant-induced beta2-integrin activation for firm adhesion of leukocytes. Furthermore, P-selectin mediates heterotypic aggregation of activated platelets to cancer cells and adhesion of cancer cells to stimulated endothelial cells.³

P-selectin, released from the cell surface, circulates as a soluble molecule in the plasma. It was shown that soluble P-selectin (sP-selectin) can exert procoagulant activity and it might therefore play an important role in thrombosis and acute coronary events. sP-selectin is often used as a marker of platelet activation.⁴