title: Peroxynitrite induces integrin-dependent adhesion of human neutrophils to endothelial cells via activation of the Raf-1/MEK/Erk pathway.
abstract: Accumulating evidence suggests that enhanced peroxynitrite (ONOO-) formation occurs during inflammation. We have studied the impact and the mechanisms of ONOO- action on expression of adhesion molecules on human neutrophils and coronary artery endothelial cells (HCAEC) and binding of neutrophils to HCAEC. Addition of ONOO- (0.1 to 200 5M) to isolated neutrophils resulted in a concentration-dependent down-regulation of L-selectin expression, and up-regulation of CD11b/CD18 expression. ONOO- stimulation of Erk activity was accompanied by activation of Ras, Raf-1 and MEK (mitogen-activated protein kinase kinase), and was sensitive to the MEK inhibitor PD 98059. We have observed a tight association between Erk activation and changes in CD11b/CD18 expression. ONOO- also evoked activation of neutrophil p38 MAPK. Neither ONOO--induced up-regulation of CD11b/CD18 expression nor Erk activation was affected by SB 203580, a selective inhibitor of p38 MAPK. ONOO- by itself had little effect on expression of ICAM-1 and E-selectin on HCAEC, whereas it markedly enhanced attachment of neutrophils to lipopolysaccharide-activated HCAEC only when it was added together with neutrophils. Increases in neutrophil adhesion evoked by ONOO- were blocked by an anti-CD18 monoclonal antibody. These data suggest that ONOO- activates Erk in neutrophils via the Ras/Raf-1/MEK signal transduction pathway, leading to up-regulation of surface expression of CD11b/CD18 and consequently to increased neutrophil adhesion to endothelial cells.
authors: Research Center, Maisonneuve-Rosemont Hospital and Department of Medicine, University of Montréal, Montréal, Québec, Canada H1T 2M4.
authors: C
authors: C
authors: Zouki
authors: S L
authors: SL
authors: Zhang
authors: J S
authors: JS
authors: Chan
authors: J G
authors: JG
authors: Filep
mesh_terms: D018821:CD18 Antigens / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D003331:Coronary Vessels; D019040:E-Selectin / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D019041:L-Selectin / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D016177:Macrophage-1 Antigen / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008954:Models, Biological; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D009566:Nitrates / Q000494:pharmacology*; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism*; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D018821:CD18 Antigens; D019040:E-Selectin; D005419:Flavonoids; D016023:Integrins; D008070:Lipopolysaccharides; D016177:Macrophage-1 Antigen; D009566:Nitrates; D018799:Intercellular Adhesion Molecule-1; D019041:L-Selectin; C039642:peroxynitric acid; D019908:Proto-Oncogene Proteins c-raf; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one