Chen De-Ju, Xu Yan-Ming, Zheng Wei, Huang Dong-Yang, Wong Wing-Yan, Tai William Chi-Shing, Cho Yong-Yeon, Lau Andy T Y
Laboratory of Cancer Biology and Epigenetics, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, P. R. China.
The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, Guangdong, P. R. China.
Proteomics. 2015 Sep;15(17):3075-86. doi: 10.1002/pmic.201400489. Epub 2015 Jun 5.
For years, many studies have been conducted to investigate the intracellular response of cells challenged with toxic metal(s), yet, the corresponding secretome responses, especially in human lung cells, are largely unexplored. Here, we provide a secretome analysis of human bronchial epithelial cells (BEAS-2B) treated with cadmium chloride (CdCl2 ), with the aim of identifying secreted proteins in response to Cd toxicity. Proteins from control and spent media were separated by two-dimensional electrophoresis and visualized by silver staining. Differentially-secreted proteins were identified by MALDI-TOF-MS analysis and database searching. We characterized, for the first time, the extracellular proteome changes of BEAS-2B dosed with Cd. Our results unveiled that Cd treatment led to the marked upregulation of molecular chaperones, antioxidant enzymes, enzymes associated with glutathione metabolic process, proteins involved in cellular energy metabolism, as well as tumor-suppressors. Pretreatment of cells with the thiol antioxidant glutathione before Cd treatment effectively abrogated the secretion of these proteins and prevented cell death. Taken together, our results demonstrate that Cd causes oxidative stress-induced cytotoxicity; and the differentially-secreted protein signatures could be considered as targets for potential use as extracellular biomarkers upon Cd exposure.
多年来，已经开展了许多研究来调查受到有毒金属挑战的细胞的细胞内反应，然而，相应的分泌蛋白质组反应，尤其是在人肺细胞中的反应，在很大程度上尚未得到探索。在此，我们对用氯化镉（CdCl₂）处理的人支气管上皮细胞（BEAS-2B）进行了分泌蛋白质组分析，目的是鉴定对镉毒性作出反应而分泌的蛋白质。来自对照和用过的培养基的蛋白质通过二维电泳进行分离，并用银染法进行可视化。通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）分析和数据库搜索来鉴定差异分泌的蛋白质。我们首次对用镉处理的BEAS-2B的细胞外蛋白质组变化进行了表征。我们的结果表明，镉处理导致分子伴侣、抗氧化酶、与谷胱甘肽代谢过程相关的酶、参与细胞能量代谢的蛋白质以及肿瘤抑制因子的显著上调。在用镉处理之前用硫醇抗氧化剂谷胱甘肽对细胞进行预处理有效地消除了这些蛋白质的分泌并防止了细胞死亡。综上所述，我们的结果表明镉会导致氧化应激诱导的细胞毒性；并且差异分泌的蛋白质特征可被视为镉暴露时潜在用作细胞外生物标志物的靶点。
