Altered Hippocampal Neurogenesis and Cognition via Maneb-mediated Changes in the Thiol Redox Proteome.

摘要 该提案的总体目标是阐明增加异生物质毒性的硫醇氧化还原机制， 改变神经突的生长并增强神经变性。巯基氧化还原蛋白质组是自适应界面 在基因组和染色体组之间，提供一种检测、避免和防御氧化剂的方法， 其他毒物。细胞巯基氧化还原系统（例如巯基氧化还原蛋白质组）的破坏是细胞巯基氧化还原系统的关键特征。 氧化应激，导致与年龄有关的疾病，包括神经变性。活性氧增强 在各种条件下，活性氧物种（ROS）的产生与线粒体功能障碍有关。因此，遗传因素 或疾病过程，导致增加的基础水平的压力，可能会导致增加的易感性， 某些人群暴露于环境中。我们的初步数据表明患有唐氏症的人 综合征（DS）可能是敏感的外源性物质的毒性作用，由于其增强的基础水平的压力。 DS是最常见的遗传形式的智力残疾和认知表型可以高度可变。 这种变异性不能完全用遗传学来解释。此外，由于淀粉样蛋白的三倍化， 前体蛋白基因（APP），所有DS患者发展阿尔茨海默病样病理。根据初步数据 和已发表的报告中，假设环境暴露有助于认知表型 通过破坏巯基氧化还原信号传导和控制的可变性，由于细胞应激的基础水平提高， 线粒体功能障碍因为ER和氧化应激是 神经退行性变，这项建议将调查的作用，氧化还原信号的影响，MB对干细胞 这些暴露如何影响神经突生长，以及认知功能如何改变 在DS转基因小鼠模型中。在具体目标1中，我们将阐明增强MB的机制 DS中的毒性。具体而言，我们将研究氧化应激，内质网应激和线粒体的作用， 功能障碍在MB介导的DS毒性中起作用。在具体目标2中，我们将利用iPS细胞衍生的神经 从DS患者和整倍体对照的祖细胞和成熟神经元来评估疾病和毒物， 介导的神经突生长的变化，使用高内容成像技术。干预措施也将 研究氧化应激和内质网应激对神经突生长的影响。的改变 神经元巯基氧化还原蛋白质组也将使用同位素编码的亲和标签（ICAT）氧化还原 蛋白质组学最后，在特定目标3中，将使用DS的体内小鼠模型Dp（16）1 Yey/+来确定 DS和MB暴露对认知功能的影响。这一目标也将表征MB介导的 海马神经变性，并阐明海马中改变的氧化还原敏感途径 通过ICAT氧化还原蛋白质组学损害学习和记忆。成功实现这些目标将为 对ER应激、细胞氧化还原状态和巯基氧化还原蛋白质组在 认知和神经退化

Abstract The overall goal of this proposal is to elucidate the thiol redox mechanisms that increase xenobiotic toxicity, alter neurite outgrowth, and enhance neurodegeneration. The thiol redox proteome is the adaptive interface between the genome and exposome, providing a means to sense, avoid, and defend against oxidants and other toxicants. Disruption of cellular thiol redox systems, e.g. thiol redox proteome, is a key feature of oxidative stress, contributing to age-related diseases, including neurodegeneration. Enhanced reactive oxygen species (ROS) production in a variety of conditions is linked to mitochondrial dysfunction. Thus, genetic factors or disease processes that cause increased basal levels of stress may result in increased susceptibility of certain populations to environmental exposures. Our preliminary data indicate that individuals with Down syndrome (DS) may be sensitive to the toxic effects of xenobiotics due to their enhanced basal levels of stress. DS is the most common genetic form intellectual disability and the cognitive phenotype can be highly variable. This variability cannot be completely explained by genetics. Additionally, due to a triplication of the amyloid precursor protein gene (APP), all DS patients develop Alzheimer's-like pathology. Based upon preliminary data and published reports, it is hypothesized that environmental exposures contribute to cognitive phenotype variability via disrupted thiol redox signaling and control due to enhanced basal levels of cellular stress and mitochondrial dysfunction. Because ER and oxidative stress are fundamental mechanisms of neurodegeneration, this proposal will investigate the role of redox signaling in the effects of MB on stem cells derived from DS patients, how these exposures affect neurite outgrowth, and how cognitive function is altered in a transgenic mouse model of DS. In Specific Aim 1, we will elucidate the mechanisms of enhanced MB toxicity in DS. Specifically, we will study the roles that oxidative stress, ER stress and mitochondrial dysfunction play in MB-mediated toxicity in DS. In Specific Aim 2, we will utilize iPS cell-derived neural progenitor cells and mature neurons from DS patients and euploid controls to evaluate disease- and toxicant- mediated changes in neurite outgrowth using high-content imaging techniques. Interventions will also be employed to investigate the impact of oxidative stress and ER stress on neurite outgrowth. Alterations in neuronal thiol redox proteome will also be determined using isotope-coded affinity tag (ICAT) redox proteomics. Lastly, in Specific Aim 3 an in vivo mouse model of DS, Dp(16)1Yey/+, will be used to determine the influence of DS and MB exposure on cognitive function. This aim will also characterize MB-mediated neurodegeneration of the hippocampus, and elucidates redox sensitive pathways altered in the hippocampus that impair learning and memory via ICAT redox proteomics. Successful completion of these aims will provide a mechanistic understanding of the role of ER stress, cellular redox status, and the thiol redox proteome in cognition and neurodegeneration.