Project 3: Molecular Mechanisms

有机磷农药(Op)是全世界和华盛顿应用最广泛的农药之一。 州政府。在成年人中，OP通过抑制酶的能力被认为是神经毒物， 乙酰胆碱酯酶(AChE)。在发育中的生物体中，OP是否诱导发育仍不清楚 神经毒性是乙酰胆碱酯酶抑制的结果。来自儿童队列研究的更多报告表明怀孕 接触杀虫剂是公共卫生问题。当前的风险评估和管理策略可能不会 使用乙酰胆碱酯酶抑制作为调节锚是最佳的。本项目将考察这一关系 在乙酰胆碱酯酶抑制和神经毒性之间的深度，跨越出生前和出生后的发育生命阶段。这个 我们建议的总体假设是，农药暴露通过以下方式改变啮齿动物的神经发育和行为 在关键时期干扰控制中枢神经系统增殖、分化和凋亡的细胞通路 “敏感性窗口”，并且这些机制独立于AChE抑制。在体外使用 对于出生前和出生后发育阶段的神经发育阶段特定模型，我们建议评估 OP诱导的氧化应激的作用及其对这些重要的细胞通路的影响 中枢神经系统发育的基础。具体目的是：(L)研究有机磷农药对轴突生长的直接影响， 神经发育阶段特异性体外模型(人干细胞、小鼠)中神经元的增殖和活性 神经元前体细胞和啮齿动物海马神经元)；(2)阐明OP诱导氧化的影响 应激和对神经发生的影响；(3)研究发育阶段特定的OP对增殖和 分化基因表达途径；(4)探讨OP对神经胶质细胞-神经元通讯的影响。 这些拟议的实验将对OP诱导的机制提供重要的新见解 神经毒性和乙酰胆碱酯酶抑制在出生前后神经发育中的作用。密切合作 随着生物统计、建模和风险表征设施的核心，这些研究的结果将是 集成并转化为开发与风险评估相关的生物学和基于路径的模型 不同的发育时期和不同物种。

Organophosphates pesticides (OP) are among the most widely applied pesticides worldwide and in Washington state. In adults, OPs are recognized to act as neurotoxicants through their ability to inhibit the enzyme, acetylcholinesterase (AChE). In the developing organism it is still unknown whether OP-induced developmental neurotoxicity is a consequence of AChE inhibition. Increased reports from child cohort studies suggest gestational exposures to pesticides are of public health concern. Current risk assessment and management strategies may not be optimal with the use of AChE inhibition as a regulatory anchor. This project will examine the relationship between AChE inhibition and neurotoxicity in depth, across pre- and postnatal developmental life stages. The overall hypothesis of our proposal is that pesticide exposure alters neurodevelopment and behavior in rodents by interfering with cellular pathways controlling proliferation, differentiation and apoptosis in the CNS during critical "windows of susceptibility" and that these mechanisms are independent of AChE inhibition. Using in vitro neurodevelopmental-stage specific models for both pre and postnatal developmental periods, we propose to assess the role of OP-induced oxidative stress and its consequential impact on these important cellular pathways, which underlie CNS development. The specific aims are: (l)to investigate the direct effects of OPs on neurite outgrowth, neuronal proliferation and viability in neurodevelopment-stage specific in vitro models (human stem cells, mouse neuronal precursor cells, and rodent hippocampal neurons);(2)to elucidate the impacts of OP-induced oxidative stress and effects on neurogenesis; (3)to examine developmental stage specific OP impacts on proliferation and differentiation gene expression pathways; and(4) to investigate OP effects on glial-neuronal communication. These proposed experiments will provide significant new insight into the mechanisms of OP-induced neurotoxicity and the role of AChE inhibition during pre- and post-natal neurodevelopment. Working closely with the Biostatistics, Modeling and Risk Characterization Facility Core, results from these studies will be integrated and translated into developing biological and pathway based models relevant for risk assessment across developmental periods and across species.