Comparative mechanistic study of developmental neurotoxicity of organophosphorus pesticides

有机磷农药发育神经毒性的比较机制研究

基本信息

批准号：
10653649
负责人：
Eva-Maria Schoetz Collins
金额：
$ 39.49万
依托单位：
SWARTHMORE COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10653649
关键词：
Accounting Acetylcholinesterase Acute Affect Amputation Animals Behavior Behavior Disorders Behavioral Benchmarking Bioinformatics Brain Brain Injuries Butyrylcholinesterase Chemicals Chlorpyrifos Cholinesterases Chronic Defect Development Developmental Process Diazinon Dichlorvos Dose Drug Kinetics Dugesia (turbellarian)Environment Event Exposure to Foundations Fresh Water Future Genes Genetic Goals Guidelines Health Hour Human Immunohistochemistry Individual Infant Insecticides Kinetics Knowledge Legal Link Malathion Mammals Molecular Molecular Target Natural regeneration Nervous System Nervous System Physiology Nervous System Trauma Neuroanatomy Outcome Pathway interactions Pesticides Phenotype Planarians Process Regulation Research Sampling Speed System Testing Time Toxic effect Toxicology Translating Translations Work adverse outcome asexual behavioral phenotyping behavioral study cholinergic combinatorial comparative cost developmental neurotoxicity differential expression high throughput screening innovation neurodevelopment neurotoxicity pesticide exposure pesticide interaction pesticide poisoning prenatal screening tool transcriptome transcriptome sequencing transcriptomics undergraduate student

项目摘要

Organophosphorus pesticides (OPs), a large and chemically diverse class, are the most commonly used and economically important insecticides worldwide, accounting for approximately 40% of recently used insecticides in the U.S. While legal OP concentrations are not acutely toxic to humans, studies suggest that chronic prenatal and infant exposures can lead to life-long neurological damage and behavioral disorders. Acute OP poisoning due to inhibition of acetylcholinesterase (AChE) is well-understood. But, despite decades of OP research, it remains debated whether and how subacute OP exposure at regulated levels that do not significantly inhibit AChE damages the developing human brain. Much of this controversy is because connections between target molecules/pathways and adverse health outcomes are largely unknown since organismal screening in mammals that could yield these connections is extremely slow and expensive. Thus, there is a critical need for high- throughput (HT) non-mammalian organismal screening to fill this knowledge gap. Additionally, humans often encounter several OPs simultaneously, due to their ubiquity and frequent use in mixtures. Thus, it is imperative to understand the toxicity mechanisms of different OPs individually and in combinations to unravel possible non- additive toxic effects and to accurately predict toxicity of combinatorial exposure to humans. The overarching goal of this research is to reveal the mechanisms underlying DNT of OPs and OP mixtures, to inform prenatal OP exposure guidelines. The specific objective is to use comparative OP HT screening in planarians to test the hypothesis that phenotypic differences associated with OP DNT are due to interactions with different molecular targets. Findings from the PI’s ongoing R15 using automated behavioral screening in the asexual freshwater planarian Dugesia japonica support this hypothesis. Subchronic exposure to 7 OPs produced different phenotypes that could not be explained by levels of AChE inhibition. Five of these OPs produced robust behavioral defects in regenerating planarians at sublethal concentrations. The proposed work builds upon these results to determine the mode of action of these 5 OPs. The hypothesis will be tested by investigating the developmental periods most vulnerable to OP exposure using a tiered screening approach (Aim 1) and by identifying which molecular pathways within these periods are affected using whole transcriptome RNA sequencing (Aim 2). The proposed project is innovative, because it is the first study that combines state-of-the- art behavioral HT screening, cellular / neuroanatomical studies, and transcriptomics to unravel the mechanisms of DNT of multiple OPs and establish connections between disrupted neurodevelopmental processes and organismal adverse outcomes. This mechanistic understanding will provide a framework to unravel the mechanisms of multi-OP interactions in future studies. Toxicity pathways identified in planarians can be used to guide targeted mechanistic studies in mammalian systems, dramatically speeding up the testing pipeline and allowing for the translation of these results to human health.

有机磷农药（OPS）是一种大型且化学多样的阶级，是最常用的，并且全球经济上重要的杀虫剂，约占最近使用的杀虫剂的40％在美国，虽然法律OP浓度对人类没有急性毒性，但研究表明慢性产前婴儿暴露会导致终身神经损害和行为障碍。急性OP中毒由于抑制乙酰胆碱酯酶（ACHE）是充分理解的。但是，尽管经过数十年的OP研究，仍在争论中是否以及如何在不显着抑制的调节水平下进行亚急性OP暴露疼痛会损害发展中的人脑。这一争议的大部分是因为目标之间的联系自哺乳动物中有机筛查以来，分子/途径和不良健康结果在很大程度上是未知的可能会产生这些连接非常缓慢且昂贵。那是高度的迫切需求吞吐量（HT）非哺乳动物有机筛查以填补这一知识空白。另外，人类经常由于它们的无处不在，并且经常用于混合物，因此很简单地遇到了几种操作。那是当务之急要分别了解不同OP的毒性机制，并结合使用，以揭示可能的非 - 加性毒性作用，并准确预测联合暴露于人类的毒性。总体这项研究的目标是揭示OP和OP混合物的DNT的机制，以告知产前 OP暴露指南。具体的目标是使用平面主义者中的比较操作筛查进行测试与OP DNT相关的表型差异的假设是由于与不同的相互作用分子靶标。使用自动行为筛选，来自PI正在进行的R15的发现 Japonica淡水Planarian Dugesia支持这一假设。亚基疫苗暴露于7个OPS产生不同的无法通过ACHE抑制水平来解释的表型。其中五个行动产生了强大的在浓度下，再生平面的人的行为缺陷。拟议的工作建立在这些基础上确定这5个OPS的作用方式的结果。该假设将通过研究使用分层筛选方法（AIM 1）和通过使用整个转录组RNA确定这些时期内哪些分子途径受到影响测序（AIM 2）。拟议的项目具有创新性，因为这是第一项结合最新的研究艺术行为HT筛查，细胞 /神经解剖学研究和转录组学，以揭示机制多个OP的DNT，并在神经发育过程中建立连接生物体不利结果。这种机械理解将提供一个框架来解开在未来的研究中，多op相互作用的机制。在平面主义者中确定的毒性途径可用于指导哺乳动物系统中的有针对性的机械研究，大大加快了测试管道和允许将这些结果转换为人类健康。