Single-cell genetic analysis of the pathogenic role of neuronal genomic instability in environmental toxicant exposure

环境毒物暴露中神经元基因组不稳定性致病作用的单细胞遗传学分析

基本信息

批准号：
10057617
负责人：
Xiaohong Lu
金额：
$ 21.9万
依托单位：
LOUISIANA STATE UNIV HSC SHREVEPORT
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：
2020-09-22 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10057617
关键词：
ATM Signaling Pathway ATM activation Accounting Adult Aging Air Pollutants Antiparkinson Agents Attenuated Base Excision Repairs Brain Brain Diseases Caffeine Cells Coffee Color Consumption DNA DNA Damage DNA Repair DNA analysis Development Disease Environment Environmental Risk Factor Exposure to Fluorescence Frameshift Mutation Frequencies Genetic Genome Stability Genomic Instability Goals Human Human Genome Huntington Disease Lead Length Link Literature Mediating Membrane Metals Methods Microsatellite Instability Mitochondrial DNA Modeling Mosaic Viruses Mosaicism Mutation Nerve Degeneration Neurodegenerative Disorders Neurons Nuclear Organic solvent product Oxidative Stress Paraquat Parkinson Disease Pathogenesis Pathogenicity Pathologic Pathology Pathway interactions Pesticides Pharmacology Play Proteins Recombinant adeno-associated virus (rAAV)Reporter Reporting Research Resolution Risk Role Rotenone Site Somatic Cell Somatic Mutation Stroke Toxic Environmental Substances Toxicant exposure Transgenic Organisms Visualization age related alpha synuclein ataxia telangiectasia mutated protein base cell type dopaminergic neuron druggable target epidemiology study gene environment interaction gene repair genetic analysis genetic variant in vivo knock-down mouse model novel oxidative DNA damage ratiometric repaired response sensor synucleinopathy targeted treatment temporal measurement tool vector

项目摘要

Project Summary/Abstract The majority of all Parkinson’s disease (PD) cases have no identifiable inheritance and occur in a sporadic form. Epidemiologic studies have found an increased risk of PD associated with exposure to environmental, while the reduced risk of PD associated with coffee consumption. The recent single-neuron sequencing studies offer direct evidence there is an age-dependent increase of somatic brain mutations, suggesting adult terminally differentiated neurons can acquire somatic mutations, possibly precipitated by environmental factors. Given the plethora of correlational evidence describing pathological conditions in which levels of DNA damage/response and mutations were identified, the most critical question is the extent to which the significance of such DNA instability has relevance for the pathogenesis of neurodegeneration. One clue comes from a protective environmental factor of PD, caffeine. Its antiparkinsonian effects have been attributed to the potent inhibition of the Ataxia-Telangiectasia Mutated (ATM) pathway. ATM is the key orchestrator of oxidative stress and DNA damage response (DDR). Robust DDR has been closely connected to multiple neurodegenerative disorders. We hypothesize that the exposure to PD associated environmental toxicants compromises genomic stability to abnormally activate the DNA damage response (converging on ATM activation), which plays a central pathogenic role to lead to the final demise of neurodegeneration. Attenuating abnormally activated ATM signaling is neuroprotective. Employing our newly developed Mosaicism with Repeat Frameshift (MORF) strategy, we demonstrated the instability of a hypermutable repeat sequence (accounting for 3% of human genome) could be harnessed for sparse and stochastic visualize neurodegeneration and genomic instability in aging, stroke, and neurodegeneration. In aim 1, we will develop an AAV mediated quantitative ratiometric sensor of genomic instability that integrates the varying lengths of mononucleotide repeats, incompatible LoxP sites, and membrane-tethered multi-color fluorescence proteins. We will use both AAV and transgenic MORF strategy to track single-neuron with DNA instability after environmental toxicant exposure to determine the pathologic consequence. In aim 2, we will determine if the genetic reduction of DNA damage response in somatic cells with DNA instability can rescue DA neuron degeneration. Our project will develop a novel genetic sensor and actuator to study somatic brain mosaicism. The results will reveal the pathogenic significance of environment-driven neuronal genomic instability and the crucial role of the DDR pathway, thus transforming the current paradigm of the pathogenic role of environmental toxicant exposure in sporadic PD. 1

项目概要/摘要大多数帕金森病 (PD) 病例没有可识别的遗传性，并且呈散发性。流行病学研究发现，帕金森病的风险增加与暴露于环境有关，而最近的单神经元测序研究提供了直接的证据。有证据表明，体细胞脑突变呈年龄依赖性增加，这表明成人晚期分化的神经元可以获得体细胞突变，这可能是由环境因素引起的。大量相关证据描述了 DNA 损伤/反应水平的病理状况并确定了突变，最关键的问题是这种 DNA 的重要性在多大程度上不稳定性与神经退行性变的发病机制有关，其中一条线索来自于保护性。 PD 的环境因素咖啡因的抗帕金森病作用归因于其有效的抑制作用。共济失调毛细血管扩张突变 (ATM) 通路是氧化应激和 DNA 的关键协调者。损伤反应（DDR）与多种神经退行性疾病密切相关。我们发现暴露于与帕金森病相关的环境毒物会损害基因组稳定性异常激活 DNA 损伤反应（收敛于 ATM 激活），该反应起着核心作用导致神经退行性病变最终消亡的致病作用。采用我们新开发的重复移码镶嵌 (MORF) 策略，我们证明了超可变重复序列（占人类基因组的 3%）的不稳定性利用稀疏和随机的可视化神经退行性变和衰老、中风和基因组不稳定性在目标 1 中，我们将开发一种 AAV 介导的基因组定量比率传感器。整合了不同长度的单核苷酸重复、不兼容的 LoxP 位点的不稳定性，以及我们将使用 AAV 和转基因 MORF 策略来构建膜束缚的多色荧光蛋白。追踪环境毒物暴露后 DNA 不稳定的单神经元以确定病理学在目标 2 中，我们将确定体细胞中 DNA 损伤反应的遗传减少是否与 DNA 不稳定性可以挽救 DA 神经元退化。我们的项目将开发一种遗传新型传感器和执行器。研究体脑嵌合现象的结果将揭示环境驱动的致病意义。神经元基因组的不稳定性和 DDR 通路的关键作用，从而改变了当前的范式环境毒物暴露在散发性帕金森病中的致病作用。 1