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

摘要 这项提议的总体目标是阐明增加异种生物毒性的硫醇氧化还原机制， 改变轴突生长，促进神经退行性变。硫醇氧化还原蛋白质组是适应性界面 在基因组和曝光组之间，提供了一种感知、避免和防御氧化剂和 其他毒物。细胞内硫醇氧化还原系统的破坏，例如硫醇氧化还原蛋白质组，是 氧化应激，导致与年龄有关的疾病，包括神经退化。增强型活性氧 物种(ROS)在各种条件下的产生与线粒体功能障碍有关。因此，遗传因素 或者，导致基础压力水平增加的疾病过程可能会导致更多的 某些人群暴露在环境中。我们的初步数据显示，唐氏综合症患者 综合征(DS)可能对外源物质的毒性作用敏感，因为它们的基础应激水平增加。 DS是最常见的遗传形式的智力残疾，认知表型可能有很大的差异。 这种可变性不能完全用遗传学来解释。此外，由于淀粉样蛋白的三倍 前体蛋白基因(APP)，所有DS患者都会发生阿尔茨海默病样病理。根据初步数据 和已发表的报告，假设环境暴露会影响认知表型 由于细胞应激和细胞内基础水平的增强，硫醇氧化还原信号和控制中断所致的可变性 线粒体功能障碍。因为内质网和氧化应激是 神经变性，这项提议将研究氧化还原信号在MB对干细胞的影响中的作用 来自DS患者，这些暴露如何影响轴突生长，以及认知功能如何改变 在DS的转基因小鼠模型中。在具体目标1中，我们将阐明增强MB的机制 DS的毒性。具体地说，我们将研究氧化应激、内质网应激和线粒体 功能障碍在亚甲基蓝介导的DS毒性中起作用。在具体目标2中，我们将利用iPS细胞来源的神经 DS患者和整倍体对照的祖细胞和成熟神经元以评估疾病和毒物- 使用高含量成像技术调节轴突生长的变化。干预措施也将是 用来研究氧化应激和内质网应激对轴突生长的影响。中的更改 神经元硫醇氧化还原蛋白质组也将使用同位素编码亲和标签(ICAT)氧化还原来确定 蛋白质组学。最后，在特定的目标3中，将使用DS的体内小鼠模型DP(16)1Yey/，来确定 DS和MB暴露对认知功能的影响这一目标也将成为甲基溴中介的特征 海马神经退行性变，并阐明海马区氧化还原敏感通路的改变 这会通过ICAT氧化还原蛋白质组学损害学习和记忆。成功完成这些目标将提供 内质网应激、细胞氧化还原状态和硫醇氧化还原蛋白质组在内质网应激中的作用 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.