Mechanism of Peroxiredoxin 3 in a Model of Pesticide-Mediated Neurodegeneration

描述(申请人提供)：环境农药暴露与帕金森氏病(PD)的发生有关，帕金森病是美国最常见的神经退行性运动障碍。流行病学调查表明，接触杀虫剂百草枯(PQ)和曼尼布(MB)会增加帕金森病的风险，但其潜在机制尚不清楚。线粒体氧化应激似乎是帕金森病的环境原因的中心，这一点得到了抗氧化剂谷胱甘肽(GSH)的研究的支持。然而，最近的数据表明，过氧化还蛋白3(Prx3)是一种由抗氧化剂硫氧还蛋白-2(Trx2)支持的过氧化物酶，在线粒体过氧化代谢中起着主导作用。Trx2的氧化通过线粒体通透性转变和凋亡信号调节蛋白-1(ASK1)的激活来激活细胞死亡机制。这项研究旨在探讨Trx2/Prx3系统是黑质线粒体重要的抗氧化剂系统的假说，该系统被MB增强的PQ毒性破坏。为了实现这一目标，将使用两个特定的目标，包括体外和体内模型。在目标1中，多巴胺能SH-SY5Y细胞将被PQ、MB或两者联合处理，以评估应激反应、Trx2/Prx3氧化的增强和细胞死亡途径的激活。这项研究将涉及线粒体的特定机制靶点和基于质谱学的蛋白质组学分析。为了检测MB介导的效应，将测量乙醛脱氢酶活性和细胞内铜积累。在目的2中，将使用遗传小鼠模型(Prx3过表达小鼠)来研究PQ+MB在体内对线粒体氧化还原的特异性影响。丰度和隔室氧化还原效应将通过基于质谱学的蛋白质组学和基于发现的代谢组学分析来衡量。这项研究将为将来将结果转化为人体研究提供基础，在人体研究中，可以获得接触过的农场工人的档案样本。最后，这些研究将促进对Trx2/Prx3系统在农药介导的神经变性中的机制作用的理解。

DESCRIPTION (provided by applicant): Environmental pesticide exposure is connected to the occurrence of Parkinson's disease (PD), the most common neurodegenerative movement disorder in America. Epidemiological investigations indicate exposure to the pesticides paraquat (PQ) and maneb (MB) increase the risk of PD, but the underlying mechanisms are unknown. Mitochondrial oxidative stress appears to be central to environmental causes of PD, which is supported by research on the antioxidant glutathione (GSH). However, recent data show that peroxiredoxin 3 (Prx3), a peroxidase supported by the antioxidant thioredoxin-2 (Trx2), has a predominant role in mitochondrial peroxide metabolism. Oxidation of Trx2 activates cell death mechanisms through the mitochondrial permeability transition and activation of apoptosis signal regulating kinase-1 (ASK1). The proposed research is designed to investigate the hypothesis that the Trx2/Prx3 system is an important mitochondrial antioxidant system in the substatntia nigra that is disrupted by MB-potentiated PQ toxicity. To accomplish this, two specific aims consisting of in vitro and in vivo models will be used. In Aim 1, dopaminergic SH-SY5Y cells will be treated with PQ, MB or in combination to evaluate stress responses, potentiation of Trx2/Prx3 oxidation and activation of cell death pathways. This research will involve specific mechanistic targets of mitochondria and mass spectrometry-based proteomic analyses. To examine MB-mediated effects, aldehyde dehydrogenase activity and intracellular copper accumulation will be measured. In Aim 2, a genetic mouse model (Prx3 over- expressing mouse) will be used to study specific mitochondrial redox effects of PQ + MB in vivo. Abundance and compartmental redox effects will be measured by mass spectrometry-based proteomics and discovery- based metabolomic analyses. This research will provide a foundation for future translation of results into human studies, where archival samples from exposed farm workers are available. Lastly, these studies will advance the understanding of the mechanistic role of the Trx2/Prx3 system in pesticide-mediated neurodegeneration.