Details

Autor(en) / Beteiligte

• de Haan, Judy B.
• Bladier, Cécile
• Griffiths, Peter
• Kelner, Michael
• O'Shea, Ross D.
• Cheung, Nam Sang
• Bronson, R.T.
• Silvestro, Mary J.
• Wild, Steven
• Zheng, Shao Shan
• Beart, Philip M.
• Hertzog, Paul J.
• Kola, Ismail

Titel

Mice with a Homozygous Null Mutation for the Most Abundant Glutathione Peroxidase, Gpx1, Show Increased Susceptibility to the Oxidative Stress-inducing Agents Paraquat and Hydrogen Peroxide

Ist Teil von

• The Journal of biological chemistry, 1998-08, Vol.273 (35), p.22528-22536

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

1998

Quelle

MEDLINE

Beschreibungen/Notizen

• Glutathione peroxidases have been thought to function in cellular antioxidant defense. However, some recent studies on Gpx1 knockout (−/−) mice have failed to show a role for Gpx1 under conditions of oxidative stress such as hyperbaric oxygen and the exposure of eye lenses to high levels of H2O2. These findings have, unexpectedly, raised the issue of the role of Gpx1, especially under conditions of oxidative stress. Here we demonstrate a role for Gpx1 in protection against oxidative stress by showing that Gpx1 (−/−) mice are highly sensitive to the oxidant paraquat. Lethality was already detected within 24 h in mice exposed to paraquat at 10 mg·kg−1 (approximately 17 the LD50of wild-type controls). The effects of paraquat were dose-related. In the 30 mg·kg−1-treated group, 100% of mice died within 5 h, whereas the controls showed no evidence of toxicity. We further demonstrate that paraquat transcriptionally up-regulatesGpx1 in normal cells, reinforcing a role forGpx1 in protection against paraquat toxicity. Finally, we show that cortical neurons from Gpx1 (−/−) mice are more susceptible to H2O2; 30% of neurons fromGpx1 (−/−) mice were killed when exposed to 65 μm H2O2, whereas the wild-type controls were unaffected. These data establish a function for Gpx1 in protection against some oxidative stressors and in protection of neurons against H2O2. Further, they emphasize the need to elucidate the role of Gpx1 in protection against different oxidative stressors and in different disease states and suggest thatGpx1 (−/−) mice may be valuable for studying the role of H2O2 in neurodegenerative disorders.