Molecular analysis of toxicant mediated teratogenesis

毒物介导的致畸的分子分析

• 批准号: 6577208
• 负责人: ORNELLA Ida SELMIN
• 金额: $ 14.22万
• 依托单位: UNIVERSITY OF ARIZONA
• 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/6577208
• 关键词: arsenic; biomarker; chick embryo; embryo /fetus toxicology; environmental contamination; environmental exposure; environmental toxicology; gene environment interaction; gene expression; growth /development; hazardous substances; laboratory rat; metal metabolism; teratogens; toxin metabolism; trichloroethylene; water supply

The overall goal of this research project is to assess whether specific developmental toxicants (e.g. trichloroethylene (TCE) and (As) arsenic) perturb one or more developmental pathways leading to morphologic alterations resulting in specific birth defects. Our main objective is to investigate is to investigate the molecular pathways altered by TCE that cause cardiac malformations in rat embryos. Our hypothesis is that analysis of markers at the molecular level will provide a sensitive index of environmental exposure. When these markers are chosen by empirical observation of altered expression, they are likely to indicate specific developmental pathways that are perturbed by toxicant exposure. As markers, these molecules can by used for promoter analysis and continued investigations into more proximally affected molecules in the tissue. Molecules critical to normal development can eventually be tested by genetic manipulation as a direct source of defects. Furthermore, we shall examine the similarities and differences of a separate potential teratogen (As versus TCE) in the developing embryos. Preliminary data indicate that several markers of exposure to TCE and As are perturbed in both heart and lungs during development. The PCR-Select subtractive hybridization technique that has been successfully used in our laboratory for TCE will also be used to isolate markers for As exposure. We propose to carry out the following specific aims: 1. Identify the distribution and timing of gene expression for four specific clones that were selected by screens for differential expression after exposure to teratogenic doses of TCE. The hypothesis is that miss-expressed molecules during developmentally significant patterns play a functional role in producing in producing heart defects. 2. Evaluate the sensitivity of altered marked expression in embryos exposed to varying levels of toxicants in maternal drinking water. Our objective is to determine minimum exposure levels that result in altered gene expression and use the most sensitive markers for risk assessment. 3. Clone the promoter region of the markers identified in aim 1. Identification of shared motifs would enable identification of molecules more proximal to the teratogenic activity of TCE. 4. Test the potential relationship between TCE exposure and the NMDA (N-Methyl-D-Aspartate) glutamate receptor and/or NFATc pathways as a mechanism of TCE teratogenicity. The hypothesis is that TCE-mediated heart defects may be caused by alterations in Ca++ flux involved with both molecules. 5. Identify and characterize markers of As exposure in developing embryos.

该研究项目的总体目标是评估特定的发育毒物（例如三氯乙烯（TCE）和（As）砷）是否会扰乱一种或多种发育途径，从而导致形态改变，从而导致特定的出生缺陷。我们的主要目的是研究 TCE 改变导致大鼠胚胎心脏畸形的分子途径。我们的假设是，分子水平上的标记分析将提供环境暴露的敏感指数。当通过对表达改变的经验观察来选择这些标记时，它们很可能表明受有毒物质暴露干扰的特定发育途径。作为标记，这些分子可用于启动子分析并继续研究组织中更接近受影响的分子。对正常发育至关重要的分子最终可以通过基因操作作为缺陷的直接来源进行测试。此外，我们将检查发育中胚胎中单独的潜在致畸剂（As 与 TCE）的异同。初步数据表明，在发育过程中，心脏和肺中暴露于 TCE 和 As 的几种标志物都会受到干扰。我们实验室已成功用于 TCE 的 PCR-Select 消减杂交技术也将用于分离砷暴露标记。我们建议实现以下具体目标： 1. 确定四个特定克隆的基因表达分布和时间安排，这些克隆是通过暴露于致畸剂量的 TCE 后进行差异表达筛选而选择的。该假设是，在发育重要模式中错误表达的分子在产生心脏缺陷中发挥功能性作用。 2. 评估暴露于母体饮用水中不同浓度有毒物质的胚胎中显着表达改变的敏感性。我们的目标是确定导致基因表达改变的最低暴露水平，并使用最敏感的标记物进行风险评估。 3. 克隆目标 1 中鉴定的标记的启动子区域。共享基序的鉴定将能够鉴定更接近 TCE 致畸活性的分子。 4. 测试 TCE 暴露与 NMDA（N-甲基-D-天冬氨酸）谷氨酸受体和/或 NFATc 途径之间的潜在关系作为 TCE 致畸性的机制。假设 TCE 介导的心脏缺陷可能是由与这两种分子相关的 Ca++ 通量的变化引起的。 5. 识别和表征发育中胚胎中砷暴露的标记。