8-Iso-PGF 2α Induces β 2 -Integrin–Mediated Rapid Adhesion of Human Polymorphonuclear Neutrophils

Abstract

Abstract —F 2 -Isoprostanes are generated from a cyclooxygenase-independent oxidative modification of arachidonic acid. They are present in atherosclerotic plaques and are platelet activators as well as potent vasoconstrictors. Polymorphonuclear neutrophils are major players in ischemia/reperfusion injury and in restenosis after PTCA. The effects of 8-isoprostaglandin (PG) F 2α on very rapid β 2 -integrin–dependent adhesion was evaluated in human neutrophils in vitro by use of purified integrin as ligand. 8-Iso-PGF 2α (1 nmol/L to 20 μmol/L) triggers a dose-dependent, very rapid neutrophil adhesion to human fibrinogen but not to the endothelial ligand intercellular adhesion molecule-1. Pretreatment with anti–β 2 -integrin subtypes showed activation of CD11b/CD18 and CD11c/CD18. Adhesion triggering was completely prevented by pertussis toxin. SQ29,548, a specific antagonist of thromboxane A2 receptor, also dose-dependently prevented 8-iso-PGF 2α –triggered neutrophil adhesion. 8-Iso-PGF 2α did not trigger adhesion in human monocytes and lymphocytes and did not induce neutrophil chemotaxis or activation of the oxygen free-radical–forming enzyme NADPH-oxidase. These data highlight the role of 8-iso-PGF 2α as a specific activator of rapid neutrophil adhesion and suggest its involvement in the pathogenesis of ischemia/reperfusion injury and in restenosis after PTCA. The effect is transduced via activation of the receptor for thromboxane A2.