title: Selenium and sulforaphane modify the expression of selenoenzymes in the human endothelial cell line EAhy926 and protect cells from oxidative damage.
abstract: OBJECTIVE
  We examined the ability of sulforaphane and selenium to modify the expression of thioredoxin reductase (TR-1) and the glutathione peroxidases (GPX-1 and GPX-4) in EAhy926 cells. The effectiveness of these agents to protect cells against peroxidative damage was also assessed.
  
  
  METHODS
  EAhy926 cells were supplemented with 40 nM of selenite and/or sulforaphane (10 microM) for 72 h and the expression of TR-1, GPX-1, and GPX-4 was assessed. Parallel cultures of selenium- and sulforaphane-treated cells were exposed to tertiary butyl hydroperoxide (t-BuOOH; 0-500 microM) for 20 h, and cell integrity was determined by the percentage of lactate dehydrogenase retained by the cellular layer.
  
  
  RESULTS
  Selenite treatment increased the concentration of TR-1 (1.6 +/- 0.17 fold, P < 0.05), GPX-1 activity (8.2 +/- 1.08 fold, P < 0.001), and GPX-4 activity (3.1 +/- 0.25 fold, P < 0.001). Sulforaphane induced TR-1 expression in selenium-deficient cells (1.83 +/- 0.11 fold, P < 0.001) and selenium-supplemented cells (2.90 +/- 0.17 fold, P < 0.001) but had no inductive effect on GPX-1 or GPX-4. The combination of selenite and sulforaphane produced an increase in TR-1 expression that was significantly greater (P < 0.001) than that achieved when each agent was added alone. Selenium and sulforaphane acted in a synergistic manner to protect cells from damage caused by t-BuOOH. The susceptibility of cells to damage by t-BuOOH increased in this order: control > sulforaphane > selenite > selenite + sulforaphane (P < 0.0001).
  
  
  CONCLUSIONS
  In endothelial cells, sulforaphane increases TR-1 but not GPX-1 and GPX-4 and in doing so confers protection against oxidative damage induced by lipid hydroperoxides. The results highlight the potential important role of TR-1 over the GPXs in protecting endothelial cells from oxidative cell damage. We also suggest that our results indicate a potential beneficial role for sulforaphane in protecting the vascular endothelium from oxidative damage.
authors.affiliation: Clinical Biochemistry, University of Edinburgh, The Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Leigh
authors.initials: L
authors.lastname: Campbell
authors.forename: Forbes
authors.initials: F
authors.lastname: Howie
authors.forename: John R
authors.initials: JR
authors.lastname: Arthur
authors.forename: Fergus
authors.initials: F
authors.lastname: Nicol
authors.forename: Geoff
authors.initials: G
authors.lastname: Beckett
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D015971:Gene Expression Regulation, Enzymologic; D005979:Glutathione Peroxidase / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D017879:Isothiocyanates; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D012643:Selenium / Q000494:pharmacology*; D013454:Sulfoxides; D013861:Thiocyanates / Q000494:pharmacology*; D013880:Thioredoxin-Disulfide Reductase / Q000187:drug effects* / Q000378:metabolism; D000094765:Glutathione Peroxidase GPX1
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D017879:Isothiocyanates; D013454:Sulfoxides; D013861:Thiocyanates; D007770:L-Lactate Dehydrogenase; D005979:Glutathione Peroxidase; D013880:Thioredoxin-Disulfide Reductase; C016766:sulforaphane; D012643:Selenium; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human