Tools for analysis of cell adhesion molecules under physiological and pathological conditions

Abstract

Among the selectin family proteins, P-selectin (CD62P) The adhesion of circulating leukocytes to the luminal is localized to the Weibel-Palade bodies of endothelial cells surface of the microvasculature is important for their and granule membranes of platelets. It is exposed on the cell recirculation and inflammatory response. The key surface upon cell activation and is the first point of contact for adhesion molecules for initiating such interactions are leukocytes adhering to activated endothelial cells or to CD44 and selectins. To investigate the roles of these activated platelets in thrombi, where it enables leukocyte molecules in the blood vessels, we reconstituted the rolling, thereby initiating the adhesion cascade. P-selectin is defined fluid flow in the microvasculature under a also found in plasma as its soluble form [11]. This form of microscope, and analyzed the cell dynamics on various P-selectin lacks the cytosolic and transmembrane domains substrates. Using this system, we found that CD44 and is derived both from the secretion of an alternatively functions as a rolling receptor for chondroitin sulfates spliced protein that lacks the transmembrane domain and under physiological flow conditions in addition to a from proteolytic cleavage of the membrane form, and it well-known ligand, hyaluronan. P-selectin also mediated reflects the activation state of endothelial cells and platelets. cell rolling by interacting with a physiological ligand Thus the soluble form of P-selectin could be a marker protein glycoprotein under such conditions. We also developed a that reflects inflammatory disorders, but how much the sensitive enzyme-linked immunosorbent assay system to soluble P-selectin level in plasma increases remains measure P-selectin, and show that P-selectin in the blood unknown. could serve as a sensitive biomarker reflecting lungIn the present study, we addressed the above issues inflammation.concerning cell adhesion molecules under physiological and pathological conditions. To this end, we have developed the