title: Relationship between p38 mitogen-activated protein kinase and small GTPase Rac for the activation of NADPH oxidase in bovine neutrophils.
abstract: Superoxide production by NADPH oxidase is essential for bactericidal properties of neutrophils. However, molecular mechanisms underlying the activation of this enzyme remain largely unknown. Here, using bovine neutrophils we examined the role of p38 mitogen-activated protein kinase (p38 MAPK) in the signaling pathways of the NADPH oxidase activation. Superoxide production was induced by stimulation with serum-opsonized zymosan (OZ) and attenuated by p38 MAPK inhibitor, SB203580. OZ stimulation induced the translocation of p47(phox) and Rac to the plasma membrane and SB203580 completely blocked the translocation of Rac, but only partially blocked that of p47(phox). Furthermore, SB203580 abolished the OZ-elicited activation of Rac, which was assessed by detecting the GTP-bound form of this protein. Phosphatidylinositol 3-kinase (PI3K) inhibitors, wortmannin and LY294002, blocked not only p38 MAPK activation but also Rac activation. However, SB203580 showed no effect on the PI3K activity. These results suggested that PI3K/p38 MAPK/Rac pathway was present in the activation of NADPH oxidase in bovine neutrophils.
authors.affiliation: Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Yamamori
authors.forename: Osamu
authors.initials: O
authors.lastname: Inanami
authors.forename: Hideki
authors.initials: H
authors.lastname: Sumimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaki
authors.forename: Hajime
authors.initials: H
authors.lastname: Nagahata
authors.forename: Mikinori
authors.initials: M
authors.lastname: Kuwabara
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002867:Chromones / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005982:Glutathione Transferase / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D007150:Immunohistochemistry; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D019255:NADPH Oxidases / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000494:pharmacology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D013997:Time Factors; D000077191:Wortmannin; D015054:Zymosan / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases; D020744:rac GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D000730:Androstadienes; D002867:Chromones; D004791:Enzyme Inhibitors; D007093:Imidazoles; D009025:Morpholines; D010750:Phosphoproteins; D011725:Pyridines; D011993:Recombinant Fusion Proteins; D013481:Superoxides; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D015054:Zymosan; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D005982:Glutathione Transferase; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020744:rac GTP-Binding Proteins; C093642:SB 203580; D000077191:Wortmannin