HORMONAL ACTIVITY OF CHLORINATED HYDROCARBONS FROM NEW YORK HARBOR SEDIMENTS

纽约港沉积物中氯化烃的激素活性

• 批准号: 6587635
• 负责人: AVROM J. CAPLAN
• 金额: $ 8.37万
• 依托单位: MOUNT SINAI SCHOOL OF MEDICINE OF CUNY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-15 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6587635
• 关键词: chlordane; chlorohydrocarbon; dichlorodiphenyltrichloroethane; environmental contamination; environmental toxicology; estradiol; gene expression; halobiphenyl /halotriphenyl compound; hazardous substances; hormone regulation /control mechanism; membrane transport proteins; soil pollution; water environment; yeasts

DESCRIPTION (Taken from application) Certain chlorinated hydrocarbon compounds (OCs), including PCBs, DDT, and chlordane, have been reported to exert estrogenic action. This project will assess a newly identified cellular and molecular mechanism of estrogenicity of organochlorines found in sediments in the lower Hudson River. Our hypothesis, which is based on studies of similar compounds in cancer cell lines and in aquatic organisms, is that a mechanism of estrogenic action of organochlorines is inhibition of MDR efflux pumps in cell membranes. We hypothesize that inhibition of the MDR pump by organochlorines increases intracellular accumulation of endogenous hormones (estradiol), with resultant adverse effects on endocrine function and development that are associated with elevated estrogen exposures. This is a novel pathway through which OCs may act as hormone mimics. In the previous project period, we observed a range of estrogenic and progestagenic responses with individual OC compounds (DDT, chlordane, PCBs, PAHs) and mixtures that mimic Hudson River sediment extracts, in tumor cell lines (Ishikawa, Var1, MCF7, T47D) as well as in the hER-yeast assay. In the next period, we propose to employ the hER yeast assay to assess the effect on the MDR pump of OCs found in the Hudson River watershed. By taking advantage of the presence of the homologous Pdr5 transporter in yeast plasma membranes, we will be able to characterize the effects of gene deletion/overexpression of membrane pumps on hormonal activity. Hormone binding and the ?-gal reporter assays (optimized in the previous project period) will be used to measure resulting estrogenic activity. Then, the capacity of chlorinated hydrocarbons to suppress the efflux of estrogenic compounds will be compared by spectroscopically monitoring the rate of efflux of rhodamine 6G (a well known pump substrate and fluorescent probe) as a function of OC concentration. In addition to xenobiotics, the molecular chaperone Hsp 90 (whose expression levels are very sensitive to the presence of xenobiotics) may regulate pump activity. We will examine the effects of changing the intracellular concentration of Hsp90, by overexpression under stress (chemical and thermal), inhibition (using the chemical geldanamycin) and gene modification.

描述（摘自申请） 某些氯化烃化合物 (OC)，包括 PCB、DDT 和 据报道，氯丹具有雌激素作用。该项目将 评估新发现的雌激素细胞和分子机制 哈德逊河下游沉积物中发现的有机氯。我们的假设， 这是基于对癌细胞系中类似化合物的研究 水生生物，是有机氯的雌激素作用机制 抑制细胞膜中的 MDR 外排泵。我们假设 有机氯抑制 MDR 泵会增加细胞内 内源性激素（雌二醇）的积累，从而产生不良反应 对内分泌功能和发育的影响与相关 雌激素暴露升高。这是 OC 可以通过的一种新途径 充当激素模拟物。在之前的项目期间，我们观察到了一系列 个别 OC 化合物（DDT、 氯丹、多氯联苯、多环芳烃）以及模仿哈德逊河沉积物提取物的混合物， 在肿瘤细胞系（Ishikawa、Var1、MCF7、T47D）以及 hER 酵母中 化验。在下一阶段，我们建议采用 hER 酵母检测来评估 哈德逊河流域发现的 OC 对 MDR 泵的影响。经过 利用酵母中同源 Pdr5 转运蛋白的存在 质膜，我们将能够表征基因的影响 膜泵的缺失/过度表达对激素活性的影响。激素 结合和 ?-gal 报告基因检测（在之前的项目中进行了优化） 期）将用于测量由此产生的雌激素活性。然后， 氯化烃抑制雌激素外流的能力 将通过光谱监测流出速率来比较化合物 罗丹明 6G（一种众所周知的泵底物和荧光探针）作为 OC 浓度的函数。除了异生素外，分子 分子伴侣 Hsp 90（其表达水平对存在非常敏感） 外源物质）可以调节泵活性。我们将检查以下效果 通过过表达来改变 Hsp90 的细胞内浓度 应激（化学和热）、抑制（使用化学格尔德霉素） 和基因修饰。