Altered transport and epigenomic changes in maneb-potentiated neurotoxicity

摘要 反复接触环境因素，如杀虫剂和金属，会改变基因表达。 模式，潜在地导致对未来有毒侮辱的敏感性增加。90%以上的 帕金森病(PD)病例被认为是特发性的，流行病学表明与 帕金森氏症中的杀虫剂。具体地说，暴露于除草剂百草枯(PQ)和杀菌剂曼尼布(MB)是 与患帕金森病风险增加75%-80%相关。此外，基因表达的表观基因组变化是 推测在帕金森病等神经退行性疾病中起作用。我之前的NIEHS资助的研究(F32 ES019821)证明，亚甲基蓝对PQ神经毒性的增强作用不仅仅是由于氧化作用增强 胁迫，但这是一个复杂的机制，涉及硫醇的MB修饰和PQ的氧化。附加基因 表达数据显示，与PQ相比，MB显著改变了更多基因的表达。亚甲基 诱导了4种不同的氨基酸转运蛋白和2种金属转运蛋白。特别感兴趣的是，丙氨酸，丝氨酸，半胱氨酸- 首选转运蛋白-1(ASCT-1(SLc1a4))和质子偶联二价金属离子转运蛋白(LSH(SLc11a1)) 与对照组相比，MB和PQ+MB的诱导作用增加了2倍以上。关于这一点的工作假设 K99/R00职业发展奖建议是长期接触甲基溴会增强PQ中介作用 修饰氨基酸增加摄取PQ引起的多巴胺能神经元退行性变 转运蛋白表达，金属介导的氧化应激和表观基因组的变化。要做到这一点，4 将使用由体外和体内模型组成的特定AIMS(2个指导，2个独立)。具体而言 AIM 1(K99指导期)，体外和体内模型将被用来确定是否增强 PQ的神经毒性是由于MB介导的ASCT-1和LSH的诱导。特定目标2(K99指导阶段) 将研究与多巴胺代谢相关的基因甲基化是否与MB- 增强了PQ的神经毒性。在特定目标3(R00独立阶段)中提出的研究将探索 长期接触农药引起组蛋白H3甲基化和乙酰化的改变。最后，具体 AIM 4(R00独立期)将研究长时间对DNA甲基组的整体改变 长期接触杀虫剂。这个项目是为了进一步发展我的研究计划，并实现战略 NIEHS的目标是通过表观基因组学研究将环境影响与疾病联系起来 培养下一代环境科学家。拟议的研究将达到这些目标，并 促进了我独立研究事业的发展。

Abstract Repeated exposure to environmental agents, such as pesticides and metals, can alter gene expression patterns, potentially resulting in enhanced susceptibility to future toxic insults. With greater than 90% of Parkinson's disease (PD) cases considered idiopathic, epidemiology has indicated the involvement of pesticides in PD. Specifically, exposures to the herbicide paraquat (PQ) and the fungicide maneb (MB) are associated with a 75-80% increased risk of PD. Additionally, epigenomic changes in gene expression are postulated to play a role in neurodegenerative disorders like PD. My previous NIEHS funded research (F32 ES019821) demonstrated that MB-potentiation of PQ neurotoxicity was not simply due to enhanced oxidative stress, but a complex mechanism involving thiol-modification by MB and oxidation by PQ. Additional gene expression data show that MB significantly altered the expression of more genes compared to PQ. MB induced 4 different amino acid transporters and 2 metal transporters. Of particular interest, Ala-, Ser-, Cys- preferring transporter-1 (ASCT-1 (Slc1a4)) and proton coupled, divalent metal ion transporter (LSH (Slc11a1)) were induced greater than 2-fold by MB and PQ+MB compared to control. The working hypothesis for this K99/R00 Career Development Award proposal is that long-term exposure to MB potentiates PQ-mediated neurodegeneration of dopaminergic neurons caused by increased uptake of PQ due to modified amino acid transporter expression, metal-mediated oxidative stress and changes in the epigenome. To accomplish this, 4 specific aims (2 mentored, 2 independent) consisting of in vitro and in vivo models will be used. In Specific Aim 1 (K99 mentored phase), both in vitro and in vivo models will be employed to determine if potentiation of PQ neurotoxicity is due to MB-mediated induction of ASCT-1 and LSH. Specific Aim 2 (K99 mentored phase) will study if methylation of genes associated with dopamine metabolism is mechanistically involved in MB- potentiated PQ neurotoxicity. Research proposed in Specific Aim 3 (R00 independent phase) will explore alterations in histone H3 methylation and acetylation caused by long term pesticide exposure. Lastly, Specific Aim 4 (R00 independent phase) will investigate global alterations in the DNA methylome in response to long term pesticide exposure. This project is designed to further develop my research program and fulfill strategic goals of the NIEHS by connecting environmental influences to disease through the study of epigenomics and to train the next generation of environmental scientists. The proposed research will meet these goals and foster the development of my independent research career.