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

描述（由申请人提供）：环境农药暴露与帕金森病（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，暴露于杀虫剂百草枯（PQ）和马乃布（MB）会增加PD的风险，但其潜在机制尚不清楚。线粒体氧化应激似乎是PD的环境原因的核心，抗氧化剂谷胱甘肽（GSH）的研究支持了这一点。然而，最近的数据表明，过氧化氧还蛋白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激酶-1 （ASK1）的激活激活细胞死亡机制。该研究旨在研究Trx2/Prx3系统是黑质中一个重要的线粒体抗氧化系统的假设，该系统被mb增强的PQ毒性破坏。为了实现这一目标，将使用体外和体内模型两个特定目标。在Aim 1中，多巴胺能SH-SY5Y细胞将被PQ、MB或联合处理，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目标和基于质谱的蛋白质组学分析。为了检查mb介导的作用，将测量醛脱氢酶活性和细胞内铜积累。在Aim 2中，将使用遗传小鼠模型（Prx3过表达小鼠）来研究PQ + MB在体内的特异性线粒体氧化还原效应。丰度和区室氧化还原效应将通过基于质谱的蛋白质组学和基于发现的代谢组学分析来测量。这项研究将为将来将结果转化为人类研究奠定基础，在人类研究中，可以获得来自暴露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. PUBLIC HEALTH RELEVANCE: Pesticide exposure is believed to contribute to the development of Parkinson's disease, which affects 1% of the worldwide population. We believe that effects occur due to a combination of pesticides, which together disrupt key redox systems of mitochondria in affected nerve cells. This project is designed to test this hypothesis.