Centre for Free Radical Research, and Gravida National Research Centre for Groth and Development, Department of Pathology, University of Otago Christchurch, Christchurch, New Zealand.
FASEB J. 2013 Aug;27(8):3315-22. doi: 10.1096/fj.13-227298. Epub 2013 Apr 19.
Peroxiredoxin 2 (Prx2) is an abundant thiol protein in erythrocytes. It is oxidized readily on exposure to hydrogen peroxide (H2O2) and provides antioxidant protection by cycling between its reduced and disulfide-bonded forms. To test whether Prx2 oxidation could occur in pathological situations where neutrophils are activated, we exposed human erythrocytes to stimulated neutrophils and measured Prx2 oxidation by immunoblotting of nonreducing gels. With phorbol myristate acetate, lipopolysaccharide or Staphylococcus aureus Prx2 dimer increased from <5% to up to 100% depending on neutrophil number and incubation time. Studies with inhibitors and myeloperoxidase-deficient neutrophils showed that H2O2 generated by the neutrophil NADPH oxidase was responsible. Prx2 oxidation was detected at erythrocyte:neutrophil ratios found in blood and reversed over time as the oxidative burst subsided. Acidotic conditions also increased erythrocyte Prx2 oxidation. In a mouse model of endotoxemia induced by lipopolysaccharide, oxidized Prx2 increased transiently from <1 to 15%, then reverted to baseline by 24 h. No increase was seen in mice lacking NADPH oxidase activity. These results indicate that erythrocyte Prx2 scavenges H2O2 produced during inflammation. Oxidized erythrocyte Prx2 could be a sensitive real-time marker of systemic neutrophil activation and an early indicator of inflammation and oxidative stress.
过氧化物酶 2（Prx2）是红细胞中丰富的含硫蛋白。它在暴露于过氧化氢（H2O2）时很容易被氧化，并通过还原和二硫键结合形式之间的循环提供抗氧化保护。为了测试 Prx2 氧化是否可能发生在中性粒细胞被激活的病理情况下，我们将人红细胞暴露于刺激的中性粒细胞中，并通过非还原凝胶的免疫印迹测量 Prx2 氧化。用佛波醇肉豆蔻酸酯、脂多糖或金黄色葡萄球菌，Prx2 二聚体从<5%增加到高达 100%，具体取决于中性粒细胞数量和孵育时间。用抑制剂和髓过氧化物酶缺陷中性粒细胞进行的研究表明，中性粒细胞 NADPH 氧化酶产生的 H2O2 是负责的。在血液中发现的红细胞：中性粒细胞比例下检测到 Prx2 氧化，并随着氧化爆发的消退随时间逆转。酸性条件也会增加红细胞 Prx2 的氧化。在脂多糖诱导的内毒素血症的小鼠模型中，氧化的 Prx2 从<1 短暂增加到 15%，然后在 24 小时内恢复到基线。在缺乏 NADPH 氧化酶活性的小鼠中未见增加。这些结果表明，红细胞 Prx2 清除炎症期间产生的 H2O2。氧化的红细胞 Prx2 可能是全身中性粒细胞激活的敏感实时标志物，也是炎症和氧化应激的早期指标。
