Peroxiredoxin 6 protecting lung type Ⅱ cell injury on H2O2-induced oxidative stress
Peroxiredoxin 6 (Prdx6) has been shown to be a novel peroxidase enzyme that protects lung injury against oxidative stress in vivo. We tested the hypothesis that Prdx6 could protect lung alveolar epithelial type Ⅱ cell (AEC Ⅱ) injury from H2O2-induced oxidative stress. AEC Ⅱ were isolated from wild-type (WT), Prdx6-/- or Prdx6 overexpressor ( Tg ) mice and treated with H2O2 at doses of 50μM, 100μM, 250μM and 500μM for 24 hours. Nile red staining was used to identify AEC Ⅱ, there were no differences in morphology among WT, Prdx6-/- and Tg Prdx6 mice without H2O2 treatment; upon H2O2 treatment, AEC Ⅱ from Prdx6-/- mice showed the most severe cell damage with loss of lamellar bodies or cellular swelling compared to WT and Tg Prdx6 mice. Tg Prdx6 mice had about 10-fold value of Prdx6 protein in AEC Ⅱ lysis as WT mice. Prdx6 protein levels increased about 2-fold upon treatment with 500μM H2O2 for 24h in both WT and Prdx6 Tg mice. AEC Ⅱ viability was lower and cytotoxicity was more severe in Prdx6-/-mice than WT even at the lowest dose of 50μM H2O2, while AEC Ⅱ from Tg Prdx6 mice were less affected than WT. Annexin V and propidium iodide binding assay were used to evaluate apoptosis. AEC Ⅱ cells from Prdx6-/- mice had the highest increase in apoptotic or necrotic cells compared to these from WT at the same doses of H2O2; while AEC Ⅱ cells from Tg Prdx6 showed less apoptosis than WT. Cell membrane lipid peroxidation with DPPP was detected under fluorescence microscopy or PTI spectrofluorometer. 2 hours of treatment with 500μM H2O2 resulted in a strongest fluorescence signal in AEC Ⅱ from Prdx6-/-mice indicating remarkable cell membrane lipid peroxidation while fluorescence signal in AEC Ⅱ from Tg Prdx6 mice showed slightly increased cell membrane lipid peroxidation.Thus, AEC Ⅱ from Prdx6-/- mice are more susceptible to H2O2-induced oxidative stress, while Prdx6 Tg mice are more resistant. Therefore, Prdx6 functions as an anti-oxidant enzyme in mouse AEC type Ⅱ cell, presumably though its ability to reduce cell membrane lipid hydroperoxides.
peroxiredoxin 6 lung type Ⅱ cell H2O2 cell viability and toxicity apoptosis cell membrane lipid peroxidation (DPPP) oxidative stress.
Yan Wang Yefim Manevich Sheldon I. Feinstein Shelley A. Phelan Ye-Shih Ho Aron B. Fisher
Institute for Environmental Medicine, University of Pennsylvania Medical Center Department of Biology, Fairfield University Institute of Environmental Health Sciences, Wayne State University
国际会议
上海
英文
114-124
2006-11-16（万方平台首次上网日期，不代表论文的发表时间）