title: Nuclear Thioredoxin-1 Overexpression Attenuates Alcohol-Mediated Nrf2 Signaling and Lung Fibrosis.
abstract: Alcohol abuse, which impairs antioxidant defenses and promotes acute lung injury, increases Nrf2 nuclear translocation but nevertheless inhibits its activation of the antioxidant response element (ARE). Thioredoxin-1 (Trx1) is required for optimal Nrf2 binding and activation of the ARE, and we hypothesized that its inhibition contributes to impaired Nrf2-ARE signaling in the alcoholic lung.
  
  
  
  Lung tissue and primary lung fibroblasts (PLFs) were isolated from C57/BL6 wild-type (WT) and transgenic mice overexpressing the human Trx1 gene with a nuclear localizing sequence (NLS-Tg); some mice consumed alcohol in water prior to lung tissue and PLF isolation; in some mice, acute lung injury was induced with intratracheal bleomycin. In other experiments, PLFs were isolated from WT and NLS-Tg mice and then exposed to alcohol. Finally, PLF isolated from WT mice were transfected with Trx1 expression vector containing either a cytosolic localized sequence (NES) or a nuclear localized sequence (NLS) prior to alcohol exposure.
  
  
  
  Alcohol treatment in vivo or in vitro decreased Trx1 expression, and bleomycin-treated alcohol-fed mice had fibrotic disrepair in their lungs. In parallel, whereas alcohol exposure in vitro increased TGFβ1 expression and decreased Nrf2-ARE activity in PLF from WT mice, these effects were not observed in PLF from NLS-Tg mice. Finally, selective overexpression of Trx1 in the nucleus but not in the cytosol preserved Nrf2-ARE activity during alcohol exposure.
  
  
  
  Although alcohol-induced redox stress actually promotes Nrf2 nuclear translocation, the coincident suppression of Trx1 impairs Nrf2-ARE activity within the nuclear compartment. Nuclear overexpression of Trx1 restored Nrf2-ARE activity and attenuated alcohol-induced TGFβ1 expression and alcohol-induced exaggerate response to bleomycin-induced acute lung injury.
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.
authors.forename: Viranuj
authors.initials: V
authors.lastname: Sueblinvong
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Mills
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.|McKelvey Lung Transplant Center, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: David C
authors.initials: DC
authors.lastname: Neujahr
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Go
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.
authors.forename: Dean P
authors.initials: DP
authors.lastname: Jones
authors.affiliation: Division of Pulmonary, Allergy & Critical Care, Department of Medicine, Atlanta, Georgia.|Atlanta VAMC, Decatur, Georgia.
authors.forename: David M
authors.initials: DM
authors.lastname: Guidot
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D000431:Ethanol / Q000008:administration & dosage*; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051267:NF-E2-Related Factor 2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011658:Pulmonary Fibrosis / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013879:Thioredoxins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; C491203:TXN protein, human; D000431:Ethanol; D013879:Thioredoxins
keywords: Alcohol; Bleomycin; Lung Fibroblasts; TGFβ1; Thioredoxin-1