title: Zymosan induces NADPH oxidase activation in human neutrophils by inducing the phosphorylation of p47phox and the activation of Rac2: involvement of protein tyrosine kinases, PI3Kinase, PKC, ERK1/2 and p38MAPkinase.
abstract: Reactive oxygen species (ROS) production by the neutrophil NADPH oxidase plays a key role in host defense against pathogens, such as bacteria and fungi. Zymosan a cell-wall preparation from Saccharomyces cerevisiae is largely used to activate neutrophils in its opsonized form. In this study, we show that non-opsonized zymosan alone induced ROS production by human neutrophils. Zymosan-induced ROS production is higher than the formyl-methionyl-leucyl-phenylalanine (fMLF)- or the phorbol myristate acetate (PMA)-induced ROS production but is lower than the one induced by opsonized zymosan. Most of the zymosan-induced ROS production is intracellular. Interestingly, zymosan induced the phosphorylation of the NADPH oxidase cytosolic component p47phox on several sites which are Ser315, Ser328 and Ser345. Zymosan induced also the activation of the small G-protein Rac2. Phosphorylation of the p47phox as well as Rac2 activation were inhibited by genistein a broad range protein tyrosine kinase inhibitor and by wortmannin a PI3Kinase inhibitor. GF109203X a PKC inhibitor inhibited phosphorylation of p47phox on Ser315 and Ser328. SB203580 and UO126, inhibitors of p38MAPK and ERK1/2-pathway, respectively, inhibited phosphorylation of p47phox on Ser345. Zymosan-induced ROS production was completely inhibited by genistein and wortmannin and partially inhibited by SB203580, UO126 and GF109203X. These results show that zymosan alone is able to activate NADPH oxidase in human neutrophils via the phosphorylation of p47phox and Rac2 activation and that a protein tyrosine kinase, PI3Kinase, p38MAPK, ERK1/2 and PKC are involved in this process. These pathways could be potential pharmacological targets to treat zymosan- and S. cerevisiae-induced inflammation.
authors.affiliation: INSERM, U773, Centre de Recherche Biomédicale Bichat Beaujon CRB3, Paris F-75018, France.
authors.forename: Karama
authors.initials: K
authors.lastname: Makni-Maalej
authors.forename: Mélanie
authors.initials: M
authors.lastname: Chiandotto
authors.forename: Margarita
authors.initials: M
authors.lastname: Hurtado-Nedelec
authors.forename: Samia
authors.initials: S
authors.lastname: Bedouhene
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Gougerot-Pocidalo
authors.forename: Pham My-Chan
authors.initials: PM
authors.lastname: Dang
authors.forename: Jamel
authors.initials: J
authors.lastname: El-Benna
mesh_terms: D004789:Enzyme Activation; D006801:Humans; D066298:In Vitro Techniques; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015054:Zymosan / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D020744:rac GTP-Binding Proteins / Q000378:metabolism*; D000097766:RAC2 GTP-Binding Protein
chemical_list: D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019255:NADPH Oxidases; D019869:Phosphatidylinositol 3-Kinases; D011493:Protein Kinase C; D011505:Protein-Tyrosine Kinases; D017382:Reactive Oxygen Species; D015054:Zymosan; D048051:p38 Mitogen-Activated Protein Kinases; D020744:rac GTP-Binding Proteins; D000097766:RAC2 GTP-Binding Protein; C060505:neutrophil cytosolic factor 1; C535150:MAPK1 protein, human