Molecular Toxicology in Human Kidney Cells

人肾细胞的分子毒理学

• 批准号: 7009799
• 负责人: LAWRENCE H. LASH
• 金额: $ 1.36万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-15 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7009799
• 关键词: Molecular; Toxicology; Human; Kidney; Cells

DESCRIPTION (provided by applicant): A diverse array of environmental and occupational chemicals are nephrotoxicants. It is important to study the interaction of these chemicals because humans are generally exposed to more than one chemical at a time. As a model for these interactions, this proposal will study the effects of two environmental chemicals, trichloroethylene (TRI) and inorganic mercury (Hg), that both have the kidneys as a primary target organ. TRI is carcinogenic in both laboratory animals and in humans while Hg is acutely cytotoxic. Both chemicals also interact with glutathione (GSH). The nephrotoxicity and nephrocarcinogenicity of TRI is attributed to its bioactivation by GSH conjugation and subsequent processing to the penultimate toxic metabolite S-(1 ,2-dichlorovinyl)-L-cysteine (DCVC), which is metabolized by the cysteine conjugate beta-lyase or flavin-containing monooxygenase, to form reactive species. In contrast, the role of GSH in the handling and nephrotoxicity of Hg is more complex, with GSH having both a protective and an intoxifying role. This proposal will study the interactions between TRI, its metabolite DCVC, and Hg in confluent primary cultures of human proximal tubular (hPT) cells and rat PT (rPT) cells under identical incubation conditions. Four hypotheses will be tested: 1) Pre-exposure of hPT and rPT cells to low, subtoxic concentrations of Hg enhances the bioactivation of both TRI and DCVC by enhancement of expression and activity of enzymes involved in TRI and/or DCVC metabolism; 2) pre-exposure of hPT and rPT cells to low, subtoxic concentrations of Hg enhances cytotoxicity of both TRI and DCVC as a consequence of increases in TRI and/or DCVC bioactivation; 3) pre-exposure of hPT and rPT cells to low- to moderately-toxic concentrations of TRI or DCVC enhances Hg-induced cytotoxicity by depletion of GSH; 4) modulation of cytotoxicity of one chemical in hPT and rPT cells by pre-exposure to another chemical is associated with changes in expression of cytokines, growth factors, and/or heat shock proteins. Results from these studies will provide information on the mechanism of interaction of two important environmental toxicants in a model of human and rat kidney cells and will allow us to determine factors that contribute to species differences in susceptibility.

描述（由申请人提供）：多种环境和职业化学品都是肾毒物。研究这些化学物质的相互作用非常重要，因为人类通常一次接触不止一种化学物质。作为这些相互作用的模型，该提案将研究两种环境化学物质三氯乙烯（TRI）和无机汞（Hg）的影响，这两种化学物质都以肾脏为主要靶器官。 TRI 对实验动物和人类都有致癌作用，而汞则具有急性细胞毒性。这两种化学物质还与谷胱甘肽 (GSH) 相互作用。 TRI 的肾毒性和肾致癌性归因于其通过 GSH 结合和随后加工成倒数第二个有毒代谢物 S-(1,2-二氯乙烯基)-L-半胱氨酸 (DCVC) 的生物活性，该代谢物由半胱氨酸结合物 β-裂合酶或含有黄素的单加氧酶，形成活性物质。相比之下，GSH 在汞的处理和肾毒性中的作用更为复杂，GSH 具有保护作用和中毒作用。该提案将研究在相同孵育条件下人近端肾小管 (hPT) 细胞和大鼠 PT (rPT) 细胞汇合原代培养物中 TRI、其代谢物 DCVC 和 Hg 之间的相互作用。将测试四个假设： 1) hPT 和 rPT 细胞预先暴露于低、亚毒浓度的汞，通过增强参与 TRI 和/或 DCVC 代谢的酶的表达和活性，增强 TRI 和 DCVC 的生物活化； 2) hPT和rPT细胞预先暴露于低、亚毒性浓度的汞，由于TRI和/或DCVC生物活性增加，因此增强了TRI和DCVC的细胞毒性； 3) 将 hPT 和 rPT 细胞预先暴露于低至中等毒性浓度的 TRI 或 DCVC，通过消耗 GSH 来增强汞诱导的细胞毒性； 4)通过预先暴露于另一种化学物质来调节hPT和rPT细胞中一种化学物质的细胞毒性与细胞因子、生长因子和/或热休克蛋白表达的变化相关。这些研究的结果将提供有关人类和大鼠肾细胞模型中两种重要环境毒物相互作用机制的信息，并使我们能够确定导致物种易感性差异的因素。