LEAD-INDUCED GENE ACTIVATION

描述(改编自《调查者摘要》)：接触铅， 尤其是儿童的问题，是美国人主要关注的问题。然而，决定因素 对铅的细胞毒性作用的敏感性尚不清楚。的主要目标是 本项目旨在阐明铅抵抗的细胞机制。我们 建议用大鼠C6胶质瘤细胞作为星形胶质细胞的模型， 似乎可以保护神经元免受铅中毒的细胞。二十 已分离出抗铅C6亚系，并鉴定了三个亚系 至于对其他金属的交叉抗性，其中一种已经被证明 在细胞-细胞杂交中表现出对野生型细胞的显性。这是我们的 关于铅的运输和封存是关键决定因素的假设 以及耐铅变种会有遗传变化 导致参与这些功能的蛋白质上调。这个 具体目标是：1)鉴定耐铅变异的C6细胞 对其他金属的交叉抗性，铅的运输和外流，以及优势 具有抗铅表型。2)铅相关基因(CDNAs) 抗性将通过两种策略来隔离，一种基于差异 一是展示，二是表达克隆。所有cdna的序列 被分析。新的cDNAs将被用作探针来确定其 野生型和耐铅C6细胞的表达水平。3)小说 蛋白质将在大肠杆菌中表达，针对这些蛋白质的抗体将 与世隔绝。为了深入了解这些蛋白质的功能，这些 抗体将用于研究组织分布和亚细胞 本地化。这些蛋白质与铅结合的能力也将是 确定，因为很可能发现的一个或多个新的蛋白质将发挥作用 在铅封存或运输中的作用。这项工作将有助于识别 那些在铅中毒中起作用并可能导致洞察 个体易感性，增加我们对铅毒理学和 可能会揭示新的暴露标志物，并提出新的治疗策略。一个 我们的发现还带来了其他好处，即抗铅电池 通常对其他一些金属具有交叉抗性，因此描述了 抗药性应该会产生关于沙门氏菌毒理学的有趣信息 其他金属也是如此。

DESCRIPTION (Adapted from the Investigator's Abstract): Exposure to lead, especially of children, is of major concern in the US. Yet, determinants of sensitivity to the cytotoxic action of lead are unknown. The main goal of this project is to delineate cellular mechanisms of lead resistance. We propose to use rat C6 glioma cells as a model for astroglial cells, the cells that appear to protect neurons from lead toxicity. Twenty lead-resistant C6 sublines have been isolated, three have been characterized as to cross-resistance to other metals, and one has been demonstrated to show dominance to wild type cells in cell-cell hybrids. It is our hypothesis that transport and sequestration of lead are crucial determinants in lead toxicity and that lead-resistant variants will have genetic changes leading to up-regulation of proteins involved in these functions. The Specific Aims are: 1) To characterize lead-resistant variant C6 cells as to cross-resistance to other metals, lead transport and efflux, and dominance of the lead-resistant phenotype. 2) Genes (cDNA's) involved in lead resistance will be isolated by 2 strategies, one based on Differential Display and the second by expression cloning. Sequences of all cDNA's will be analyzed. Novel cDNA's will be used as probes to determine their expression levels in wild type and lead-resistant C6 cells. 3) Novel proteins will be expressed in E. coli, and antibodies to these proteins will be isolated. To gain insight into the function of these proteins, these antibodies will be used to study tissue distribution and sub-cellular localization. The abilities of these proteins to bind lead will also be determined, as it is likely that one or more novel proteins found will play a role in lead sequestration or transport. This work will help identify those proteins that play a role in lead toxicity and may lead to insight on individual susceptibility, increase our understanding of lead toxicology and may reveal new exposure markers and suggest new therapeutic strategies. An additional benefit results from our finding that lead-resistant cells are often cross-resistant to some other metals, so delineating the mechanisms of resistance should yield interesting information about the toxicology of other metals as well.