title: Redox regulation of adenovirus-induced AP-1 activation by overexpression of manganese-containing superoxide dismutase.
abstract: Adenovirus gene therapy is a promising tool in the clinical treatment of many genetic and acquired diseases. However, it has also caused pathogenic effects in organs such as the liver. The redox-sensitive transcription factors AP-1 and NF-kappaB have been implicated in these effects. To study the mechanisms of adenovirus-mediated AP-1 and NF-kappaB activation and the possible involvement of oxidative stress in adenovirus transduction, rats were injected with either replication-defective recombinant adenovirus with DNA containing the cytomegalovirus promoter region only (AdCMV), adenovirus containing human manganese-containing superoxide dismutase (MnSOD) cDNA (AdMnSOD), or vehicle. Compared to vehicle and AdCMV transduction, MnSOD gene transfer yielded a fivefold increase in liver MnSOD activity 7 days postinjection. Gel shift assay showed that AdCMV transduction induced DNA binding activity for AP-1 but not NF-kappaB. MnSOD overexpression abolished this activation. Western blotting analysis of c-Fos and c-Jun suggested that up-regulation of c-fos and c-jun gene expression does not directly contribute to the induction of AP-1 activation. Glutathione/glutathione disulfide ratios were decreased by adenovirus transduction and restored by MnSOD overexpression. The AP-1 binding activity that was induced by AdCMV was decreased by immunoprecipitation of Ref-1 protein. Ref-1 involvement was confirmed by restoration of AP-1 binding activity after the immunoprecipitated Ref-1 protein had been added back. AP-1 DNA binding activity was also elevated in control and AdMnSOD-injected rats after addition of the immunoprecipitated Ref-1 protein. These data indicate that cellular transduction by recombinant adenovirus stimulates AP-1 DNA binding activity. Furthermore, our results suggest that MnSOD overexpression decreases AP-1 DNA binding activity by regulating intracellular redox status, with the possible involvement of Ref-1 in this redox-sensitive pathway.
authors.affiliation: Department of Exercise Science, Free Radical and Radiation Biology Program. Department of Radiation Oncology, The University of Iowa, Iowa City, Iowa 52242, USA.
authors.forename: Hannah J
authors.initials: HJ
authors.lastname: Zhang
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Drake
authors.forename: Linjing
authors.initials: L
authors.lastname: Xu
authors.forename: Jianfang
authors.initials: J
authors.lastname: Hu
authors.forename: Frederick E
authors.initials: FE
authors.lastname: Domann
authors.forename: Larry W
authors.initials: LW
authors.lastname: Oberley
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Kregel
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019757:Carbon-Oxygen Lyases / Q000378:metabolism; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D004268:DNA-Binding Proteins / Q000378:metabolism; D005822:Genetic Vectors; D008099:Liver / Q000378:metabolism; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D011916:Rats, Inbred F344; D011995:Recombination, Genetic; D013482:Superoxide Dismutase / Q000032:analysis / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D018808:Transcription Factor AP-1; D013482:Superoxide Dismutase; D019757:Carbon-Oxygen Lyases; C470319:Apex1 protein, rat; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase