Effect of lead exposure and accumulation on copper homeostasis in cultured C6 rat glioma cells.
Effect of lead exposure and accumulation on copper homeostasis in cultured C6 rat glioma cells.
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DOI：
10.1006/taap.1999.8657
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发表时间：
1999-07
影响因子：
3.8
通讯作者：
Y. Qian;G. Mikeska;E. D. Harris;G. Bratton;E. Tiffany‐Castiglioni
中科院分区：
文献类型：
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作者：
Y. Qian;G. Mikeska;E. D. Harris;G. Bratton;E. Tiffany‐Castiglioni
C6大鼠神经胶质瘤细胞类似于培养中的大鼠星形胶质细胞，这两种细胞类型都从培养基中在细胞内积累铅（Pb）。因此，C6细胞是脑铅积累的模型。在这项研究中，对氯汞苯甲酸盐（PCMB）暴露后，10 μ M醋酸铅诱导的细胞内铅积累的增加表明巯基在铅滞留的作用。硝苯地平对铅积累的刺激表明铅通过一种新的途径进入这些细胞，1 μ M铅暴露7天后，大部分细胞内铅与细胞质中的高分子量组分有关。铅暴露增加了三种蛋白质的丰度，具有以下特征的二维凝胶：81 kDa的pI为5.6，81 kDa的pI为4。9和71 kDa，pI为5.6。其他五种蛋白质的水平下降，其大小范围为37-41 kDa，pI为6.0-6.8。暴露C6细胞内积累铜（Cu），和铅暴露后的Cu积累的动力学分析表明，与67 Cu的增加的吸收和减少流出的Cu。铅暴露的细胞也表现出增加铜结合膜，这是一致的增加铜的吸收。这些数据表明，细胞内的铅与C6细胞中的高分子量蛋白质相互作用，暴露也改变了铜的膜转运特性。
C6 rat glioma cells resemble rat astroglia in culture in that both cell types accumulate lead (Pb) intracellularly from the medium. As such, C6 cells are a model for Pb accumulation by the brain. In this study, an increase in intracellular Pb accumulation induced by p-chloromercuribenzoate (PCMB) after exposure to 10 microM Pb acetate suggests a role for sulfhydryl groups in Pb retention. Stimulation of Pb accumulation by nifedipine suggests the entry of Pb into these cells by a novel path. Most of the intracellular Pb from exposure for 7 days to 1 microM Pb was associated with high-molecular weight components in cytosol. Pb exposure increased the abundance of three proteins with the following characteristics on two-dimensional gels: 81 kDa with pI of 5.6, 81 kDa with pI of 4. 9, and 71 kDa with pI of 5.6. The levels of five other proteins, ranging in size from 37-41 kDa with pIs of 6.0-6.8 declined. Exposed C6 cells accumulated copper (Cu) intracellularly, and Cu accumulation after Pb exposure was shown by kinetic analysis with 67Cu to result from an increased uptake and a decreased efflux for Cu. Pb-exposed cells also showed increased Cu binding to membranes, which is consistent with the increase of Cu uptake. These data indicate that intracellular Pb interacts with high molecular weight proteins in C6 cells, and exposure also alters membrane transport properties for copper.