title: Thiol modulation of TNF alpha and IL-1 induced MnSOD gene expression and activation of NF-kappa B.
abstract: TNF alpha and IL-1 each can activate NF-kappa B and induce gene expression of manganese superoxide dismutase (MnSOD), a mitochondrial matrix enzyme which can provide critical protection against hyperoxic lung injury. The regulation of MnSOD gene expression is not well understood. Since redox status can modulate NF-kappa B and potential kappa B site(s) exist in the MnSOD promoter, the effect of thiols (including NAC, DTT and 2-ME) on TNF alpha and IL-1 induced activation of NF-kappa B and MnSOD gene expression was investigated. Activation of NF-kB and increased MnSOD expression were potentiated by thiol reducing agents. In contrast, thiol oxidizing or alkylating agents inhibited both NF-kappa B activation and elevated MnSOD expression in response to TNF alpha or IL-1. Since protease inhibitors TPCK and TLCK can inhibit NF-kappa activation, we also investigated the effect of these compounds on MnSOD expression and NF-kappa B activation. TPCK and TLCK each inhibited MnSOD gene expression and NF-kappa B activation. Since the MnSOD promoter also contains an AP-1 binding site, the effect of thiols and thiol modifying agents on AP-1 activation was investigated. Thiols had no consistent effect on AP-1 activation. Likewise, some of the thiol modifying compounds inhibited AP-1 activation by TNF alpha or IL-1, whereas others did not. Since diverse agents had similar effects on activation of NF-kappa B and MnSOD gene expression, we have demonstrated that activation of NF-kappa B and MnSOD gene expression are closely associated and that reduced sulfhydryl groups are required for cytokine mediation of both processes.
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D000477:Alkylating Agents / Q000494:pharmacology; D001483:Base Sequence; D004790:Enzyme Induction / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007527:Isoenzymes / Q000096:biosynthesis* / Q000235:genetics; D008175:Lung Neoplasms / Q000473:pathology; D008345:Manganese; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic; D011480:Protease Inhibitors / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000096:biosynthesis* / Q000235:genetics; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000494:pharmacology
chemical_list: D000477:Alkylating Agents; D007375:Interleukin-1; D007527:Isoenzymes; D016328:NF-kappa B; D016877:Oxidants; D011480:Protease Inhibitors; D013438:Sulfhydryl Compounds; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D014107:Tosyllysine Chloromethyl Ketone; D014108:Tosylphenylalanyl Chloromethyl Ketone; D008345:Manganese; D013482:Superoxide Dismutase