Proteomic Analysis of Oxidative Stress-Responsive Proteins in Human Pneumocytes: Insight into the Regulation of DJ-1 Expression
Proteomic Analysis of Oxidative Stress-Responsive Proteins in Human Pneumocytes: Insight into the Regulation of DJ-1 Expression
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DOI：
10.1021/pr800295j
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发表时间：
2008-11-01
影响因子：
4.4
通讯作者：
Merali, Salim
中科院分区：
文献类型：
--
作者：
Duan, Xunbao;Kelsen, Steven G.;Merali, Salim
氧化损伤被认为在肺气肿和肺癌等肺部疾病的发病机制中起重要作用。我们研究了一个经典的活性氧，过氧化氢，对过氧化氢反应蛋白（HPRP）在人肺细胞的影响，使用比较二维凝胶电泳（2DE）和肽质量指纹图谱。暴露于H2 O2（1 mM，24 h）后，4种HPRP相关蛋白（DJ-1、过氧化物酶[Prxs] I和IV以及甘油醛-3-磷酸脱氢酶[GAPDH]）发生变化。H2 O2暴露增加了DJ-1（pI分别为5.8和6.2）、Prx I和IV以及GAPDH的酸性（氧化）形式，降低了碱性（还原）形式。对DJ-1的机制研究表明，还原形式的缓慢恢复被环己酰胺阻断，表明恢复是由于新的蛋白质合成。总DJ-1的表达减少，增加浓度的过氧化氢。相比之下，香烟烟雾提取物（CSE）形式的更复杂的氧化剂混合物剂量依赖性地增加DJ-1表达并产生新的DJ-1同种型（p/5.6）。此外，与不吸烟者相比，DJ-1在慢性吸烟者的肺部表达更高，这一结果类似于CSE在培养细胞中的作用。这些数据表明，在人肺细胞中，DJ-1作为抗氧化剂发挥作用，但没有酶系统将氧化形式转化为还原形式。香烟烟雾上调DJ-1可能是一种保护肺免受氧化应激相关损伤的代偿机制。
Oxidative injury is believed to play an important role in the pathogenesis of lung diseases such as emphysema and lung cancer. We examined the effects of a classic reactive oxygen species, H2O2, on the hydrogen peroxide response proteins (HPRP) in human pneumocytes using comparative two-dimensional gel electrophoresis (2DE) and peptide mass fingerprinting. Four HPRP-associated proteins (DJ-1, peroxiredoxins [Prxs] I and IV and glyceraldehyde-3-phosphate dehydrogenase [GAPDH]) were changed upon exposure to H2O2 (1 mM for 24 h). H2O2 exposure increased the acid (oxidized) form and decreased the basic (reduced) form of DJ-1 (pI 5.8 and 6.2, respectively), Prx I and IV and GAPDH. Mechanistic studies on DJ-1 indicated that the slow recovery of the reduced form was blocked by cyclohexamide, suggesting that the recovery was due to new protein synthesis. Total DJ-1 expression was decreased by increasing concentrations of H2O2. In contrast, a more complex mix of oxidants in the form of cigarette smoke extract (CSE) dose-dependently increased DJ-1 expression and produced a novel DJ-1 isoform (p/5.6). Moreover, DJ-1 expression was higher in the lungs of chronic cigarette smokers compared with nonsmokers, a result which resembled the effects of CSE in cultured cells. These data indicate that in human pneumocytes, DJ-1 functions as an antioxidant but that no enzymatic system converts the oxidized to the reduced form. Up-regulation of DJ-1 by cigarette smoke may be a compensatory mechanism that protects the lung from oxidative stress-related injury.