title: Amplification of IL-1 beta-induced matrix metalloproteinase-9 expression by superoxide in rat glomerular mesangial cells is mediated by increased activities of NF-kappa B and activating protein-1 and involves activation of the mitogen-activated protein kinase pathways.
abstract: The modulation of cell signaling by free radicals is important for the pathogenesis of inflammatory diseases. Recently, we have shown that NO reduces IL-1beta-induced matrix metalloproteinase (MMP-9) expression in glomerular mesangial cells (MC). Here we report that exogenously administrated superoxide, generated by the hypoxanthine/xanthine oxidase system (HXXO) or by the redox cycler 2, 3-dimethoxy-1,4-naphtoquinone, caused a marked amplification of IL-1beta-primed, steady state, MMP-9 mRNA level and an increase in gelatinolytic activity in the conditioned medium. Superoxide generators alone were ineffective. Cytokine-induced steady state mRNA levels of TIMP-1, an endogenous inhibitor of MMP-9, were affected similarly by HXXO. Transient transfection of rat mesangial cells with 0.6 kb of the 5'-flanking region of the rat MMP-9 gene proved a transcriptional regulation of MMP-9 expression by superoxide. HXXO augmented the IL-1beta-triggered nuclear translocation of p65 and c-Jun and, in parallel, increased DNA binding activities of NF-kappaB and AP-1. Mutation of either response element completely prevented MMP-9 promoter activation by IL-1beta. Moreover, specific inhibitors of the classical extracellular signal-regulated kinase (ERK) pathway and p38 mitogen-activated protein kinase (MAPK) cascade, partially reversed the HXXO-mediated effects on MMP-9 mRNA levels, thus demonstrating involvement of ERKs and p38 MAPKs in MMP-9 expression. Furthermore, IL-1beta-triggered phosphorylation of all three MAPKs, including p38-MAPK, c-Jun N-terminal kinase, and ERK, was substantially enhanced by superoxide. Our data identify superoxide as a costimulatory factor amplifying cytokine-induced MMP-9 expression by interfering with the signaling cascades leading to the activation of AP-1 and NF-kappaB.
authors.affiliation: Pharmazentrum Frankfurt, Klinikum der Johann Wolfgang Goethe Universität, Frankfurt am Main, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Eberhardt
authors.forename: A
authors.initials: A
authors.lastname: Huwiler
authors.forename: K F
authors.initials: KF
authors.lastname: Beck
authors.forename: S
authors.initials: S
authors.lastname: Walpen
authors.forename: J
authors.initials: J
authors.lastname: Pfeilschifter
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics / Q000276:immunology; D001692:Biological Transport / Q000276:immunology; D002467:Cell Nucleus / Q000276:immunology / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D005784:Gene Amplification / Q000276:immunology; D005786:Gene Expression Regulation / Q000276:immunology; D005920:Glomerular Mesangium / Q000166:cytology / Q000201:enzymology* / Q000276:immunology* / Q000378:metabolism; D006868:Hydrolysis; D020672:I-kappa B Proteins; D007093:Imidazoles / Q000494:pharmacology; D007375:Interleukin-1 / Q000502:physiology*; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000276:immunology*; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000276:immunology; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism; D051381:Rats; D013481:Superoxides / Q000494:pharmacology*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis / Q000235:genetics; D018808:Transcription Factor AP-1 / Q000378:metabolism / Q000502:physiology*; D051996:Transcription Factor RelA
chemical_list: D000276:Adjuvants, Immunologic; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D020672:I-kappa B Proteins; D007093:Imidazoles; D007375:Interleukin-1; D061965:Matrix Metalloproteinase Inhibitors; D016328:NF-kappa B; C000606206:Nfkbia protein, rat; D011725:Pyridines; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D018808:Transcription Factor AP-1; D051996:Transcription Factor RelA; D013481:Superoxides; D000072000:NF-KappaB Inhibitor alpha; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D020780:Matrix Metalloproteinase 9; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one