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: 6578813
• 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: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6578813
• 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（摘自应用程序） 某些氯代烃化合物，包括多氯联苯、滴滴涕和 据报道，氯丹具有雌激素作用。该项目将 评估一种新发现的雌激素样作用的细胞和分子机制， 在哈德逊河下游的沉积物中发现的有机氯。我们的假设， 该研究是基于对癌细胞系中类似化合物的研究， 水生生物，是一种机制，雌激素作用的有机氯 是抑制细胞膜中的MDR外排泵。我们假设 有机氯对MDR泵的抑制增加了细胞内 内源性激素（雌二醇）蓄积，导致不良反应 对内分泌功能和发育的影响， 雌激素水平升高这是一个新的途径，通过它，业主立案法团可以 就像激素模拟物一样。在上一个项目期间，我们观察到一系列 雌激素和孕激素对单独OC化合物的反应（DDT， 叶绿素、多氯联苯、多环芳烃）和模拟哈德逊河沉积物提取物的混合物， 在肿瘤细胞系（石川、Var 1、MCF 7、T47 D）以及hER-酵母中 比色法在下一阶段，我们建议采用hER酵母测定法来评估 在哈德逊河流域发现的有机碳对MDR泵的影响。通过 利用酵母中同源Pdr 5转运蛋白的存在 质膜，我们将能够描述基因的影响， 膜泵的缺失/过表达对激素活性的影响。激素 约束力和？gal报告基因检测（在之前的项目中优化 周期）将用于测量产生的雌激素活性。然后 氯代烃抑制雌激素外排的能力 将通过光谱监测流出率来比较化合物 的罗丹明6 G（一种众所周知的泵基板和荧光探针）作为 OC浓度的函数。除了外源性物质， 伴侣蛋白Hsp 90（其表达水平对Hsp 90的存在非常敏感， 外源性物质）可以调节泵活性。我们将研究 改变细胞内Hsp 90的浓度，通过过表达， 强制降解（化学和热），抑制（使用化学格尔德霉素） 和基因改造。