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Keywords:

  • selenium;
  • glutathione peroxidase;
  • redox regulation;
  • NF-κB;
  • IκB

Abstract

Treatment of mammalian cells with hydrogen peroxide induces the nuclear translocation of the transcription factor NF-κ and its binding to κ DNA sequences present in the promoter region of numerous genes. The role of selenium in NF-κ activation was analyzed in human T47D cells overexpressing the seleno-dependent detoxifiant enzyme glutathione peroxidase. Following exposure to H2O2, these cells showed a seleno-dependent decreased accumulation of intracellular ROS and NF-κ activation. This phenomenon was correlated with an inhibition of the nuclear translocation of NF-κ (p50 subunit) and with an absence of Iκα degradation. We also report that the half-life of Iκα in untreated cells was increased two-fold by the overexpression of active glutathione peroxidase. These results suggest that selenium is a key element that through its modulation of glutathione peroxidase activity can inhibit NF-κ activation and can up-regulate Iκα normal half life.