title: Inhibition of extracellular signal-regulated kinase 1/2 augments nitric oxide production in lipopolysaccharide-stimulated RAW264.7 macrophage cells.
abstract: The present study was conducted to determine effects of U0126, a specific inhibitor of mitogen-activated kinase kinase 1/2, on production of nitric oxide (NO) in RAW264.7 macrophage cells. U0126 significantly enhanced NO production in lipopolysaccharide (LPS) but not CpG DNA or interferon-gamma-stimulated RAW264.7 cells. In contrast, U0124, a negative control for U0126, did not affect LPS-induced NO production. Further, a series of inhibitors of p38, phosphatidyl-inositol 3-kinase and Janus tyrosine kinase rather caused suppression in LPS-stimulated RAW264.7 cells. U0126 was found to definitely inhibit phosphorylation of extracellular signal-regulated kinase (Erk) 1/2 and augment the levels of inducible type of NO synthase. Antisense oligonucleotides of Erk1/2 also augmented LPS-induced NO production. Inactivation of Erk1/2 by U0126 furthermore inhibited LPS-induced activating protein-1 activation, but not nuclear factor-kappaB activation. The results suggest that Erk1/2 might negatively regulate NO production in LPS-stimulated RAW264.7 cells.
authors.affiliation: Department of Microbiology and Immunology, Aichi Medical University School of Medicine, Nagakute, Aichi 480-1195, Japan. nao777nk@aichi-med-u.ac.jp
authors.forename: Naoki
authors.initials: N
authors.lastname: Koide
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Ito
authors.forename: Mya Mya
authors.initials: MM
authors.lastname: Mu
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Ferdaus
authors.initials: F
authors.lastname: Hassan
authors.forename: Shamima
authors.initials: S
authors.lastname: Islam
authors.forename: Isamu
authors.initials: I
authors.lastname: Mori
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yoshida
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokochi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002070:Butadienes / Q000494:pharmacology; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D004247:DNA / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016899:Interferon-beta / Q000235:genetics; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors*; D048370:MAP Kinase Kinase 2 / Q000037:antagonists & inhibitors*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009570:Nitriles / Q000494:pharmacology; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D002070:Butadienes; C408982:CPG-oligonucleotide; D016207:Cytokines; D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; D009570:Nitriles; D009838:Oligodeoxyribonucleotides; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; C113580:U 0126; D009569:Nitric Oxide; D016899:Interferon-beta; D007371:Interferon-gamma; D004247:DNA; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D048369:MAP Kinase Kinase 1; D048370:MAP Kinase Kinase 2; C482127:Map2k1 protein, mouse; C482129:Map2k2 protein, mouse