Molecular Genetic Analysis of TORC1 and TORC2 Signaling in Neuronal Maintenance

本补充材料响应NOT-AG-20-034：特别关注的通知：以阿尔茨海默氏症为重点的管理 补充NIH的赠款，而不是集中在阿尔茨海默病。阿尔茨海默病（AD）仍然是一个 尽管进行了密集的研究和制药工作，但仍有迫在眉睫的公共卫生危机。没有有效的治疗方法 目前有一种方法可以阻止疾病的发展。最近几个备受瞩目的临床失败 针对淀粉样斑块和神经纤维缠结的试验，这是AD的病理标志， 博士Alois Alzheimer在世纪前提出的新观点和新方向， 在开发出有效的AD治疗方法之前，应该研究AD的致病机制。 在母基金中，我们建议阐明神经元维持的基本机制 通过雷帕霉素（mTOR）信号传导的机制靶点。我们确定了共翻译质量控制 线粒体外膜相关翻译作为应激下线粒体保护的关键事件， 并表明它受到与帕金森氏症有关的保守PINK 1-mTOR信号通路的调节， 疾病（PD）。在这个过程中，我们发现，这一质量控制途径也涉及到其他 神经退行性疾病环境，包括AD。在这个补充项目中，我们将测试假设， APP的生物发生需要足够的共翻译质量控制活性， 由于老化或代谢应激，可导致蛋白质稳态紊乱，从而导致或引发AD。到 为了增强本项目的疾病相关性，我们建议使用AD小鼠模型和患者来源的细胞 模型来检验这个假设。提出了两个具体目的：目的1：使用AD患者成纤维细胞和 诱导多能干细胞（iPSC）衍生的神经元，以测试共翻译质量控制在 蛋白质稳态目的2：利用5xFAD小鼠模型检测共翻译基因的遗传操作效果 对淀粉样斑块形成和行为的质量控制活性。 预计在本补充项目结束时，我们将获得以下具体证据： 共翻译质量控制在APP生物发生中的参与，建立有缺陷的共- 翻译质量控制可能是AD最早的致病事件之一。这可能深刻地 影响我们对AD发病机制的理解，并刺激新的和合理的治疗策略， 治疗和预防AD以及其他破坏性的神经退行性疾病，其中受损的共- 涉及翻译质量控制。

This supplement responds to NOT-AG-20-034: Notice of Special Interest: Alzheimer's-focused administrative supplements for NIH grants that are not focused on Alzheimer's disease. Alzheimer's disease (AD) remains a looming public health crisis, despite intensive research and pharmaceutical efforts. No effective treatment option is currently available that can halt the disease process. The recent failures of several high-profile clinical trials targeting the amyloid plaques and neurofibrillary tangles, the pathological hallmarks of AD identified by Dr. Alois Alzheimer more than a century ago, suggest that new ideas and new directions in delineating the pathogenic mechanisms of AD should be pursued before effective treatment of the disease can be developed. In the parent grant, we propose to elucidate fundamental mechanisms governing neuronal maintenance by mechanistic target of rapamycin (mTOR) signaling. We identified co-translational quality control of mitochondrial outer membrane-associated translation as a key event in mitochondrial protection under stress, and showed that it is regulated by the conserved PINK1-mTOR signaling pathway implicated in Parkinson's disease (PD). In the process, we found that this quality control pathway is also involved in other neurodegenerative disease settings, including AD. In this Supplement Project, we will test the hypothesis that the biogenesis of APP requires adequate co-translational quality control activity, the insufficient supply of which due to aging or metabolic stress can result in perturbed proteostasis that contributes to or initiates AD. To enhance the disease relevance of this project, we propose to use AD mouse model and patient-derived cellular models to test this hypothesis. Two Specific Aims are proposed: Aim 1: Using AD patient fibroblasts and induced pluripotent stem cell (iPSC)-derived neurons to test the roles of co-translational quality control in proteostasis. Aim 2: Using the 5xFAD mouse model to test the effect of genetic manipulation of co-translational quality control activity on amyloid plaque formation and behavior. It is anticipated that at the end of this Supplement Project, we will have obtained concrete evidence of the involvement of co-translational quality control in the biogenesis of APP, establishing defective co- translational quality control as potentially one of the earliest pathogenic events of AD. This may profoundly impact our understanding of AD pathogenesis and stimulate novel and rational therapeutic strategies for the treatment and prevention of AD as well as other devastating neurodegenerative diseases in which impaired co- translational quality control has been implicated.