title: Viral-mediated inhibition of antioxidant enzymes contributes to the pathogenesis of severe respiratory syncytial virus bronchiolitis.
abstract: BACKGROUND
  Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in children, for which no specific treatment or vaccine is currently available. We have previously shown that RSV induces reactive oxygen species in cultured cells and oxidative injury in the lungs of experimentally infected mice. The mechanism(s) of RSV-induced oxidative stress in vivo is not known.
  
  
  OBJECTIVE
  To measure changes of lung antioxidant enzymes expression/activity and activation of NF-E2-related factor 2 (Nrf2), a transcription factor that regulates detoxifying and antioxidant enzyme gene expression, in mice and in infants with naturally acquired RSV infection.
  
  
  METHODS
  Superoxide dismutase 1 (SOD 1), SOD 2, SOD 3, catalase, glutathione peroxidase, and glutathione S-transferase, as well as Nrf2 expression, were measured in murine bronchoalveolar lavage, cell extracts of conductive airways, and/or in human nasopharyngeal secretions by Western blot and two-dimensional gel electrophoresis. Antioxidant enzyme activity and markers of oxidative cell injury were measured in either murine bronchoalveolar lavage or nasopharyngeal secretions by colorimetric/immunoassays.
  
  
  RESULTS
  RSV infection induced a significant decrease in the expression and/or activity of SOD, catalase, glutathione S-transferase, and glutathione peroxidase in murine lungs and in the airways of children with severe bronchiolitis. Markers of oxidative damage correlated with severity of clinical illness in RSV-infected infants. Nrf2 expression was also significantly reduced in the lungs of viral-infected mice.
  
  
  CONCLUSIONS
  RSV infection induces significant down-regulation of the airway antioxidant system in vivo, likely resulting in lung oxidative damage. Modulation of oxidative stress may pave the way toward important advances in the therapeutic approach of RSV-induced acute lung disease.
authors.affiliation: Department of Pediatrics, The University of Texas Medical Branch at Galveston, Galveston, TX 77555-0366, USA.
authors.forename: Yashoda M
authors.initials: YM
authors.lastname: Hosakote
authors.forename: Paul D
authors.initials: PD
authors.lastname: Jantzi
authors.forename: Dana L
authors.initials: DL
authors.lastname: Esham
authors.forename: Heidi
authors.initials: H
authors.lastname: Spratt
authors.forename: Alexander
authors.initials: A
authors.lastname: Kurosky
authors.forename: Antonella
authors.initials: A
authors.lastname: Casola
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Garofalo
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D001988:Bronchiolitis / Q000209:etiology / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid; D002374:Catalase / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D018384:Oxidative Stress; D018357:Respiratory Syncytial Virus Infections / Q000150:complications / Q000378:metabolism*; D012136:Respiratory Syncytial Viruses / Q000378:metabolism; D012720:Severity of Illness Index; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase