Slowing proteotoxic neurodegeneration by boosting mitochondrial bioenergetics and recruiting a novel class of chaperones

通过增强线粒体生物能和招募一类新型伴侣来减缓蛋白毒性神经变性

• 批准号: 10485489
• 负责人: Antoni Barrientos
• 金额: --
• 依托单位: MIAMI VA HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10485489
• 关键词: Acceleration; Address; Age; Aging; Autophagocytosis; Binding; Bioenergetics; Biogenesis; Biosynthetic Proteins; Brain; Cell Death; Cells; Cessation of life; Complex; Cytoprotection; Data; Deposition; Deterioration; Disease; Disease Outcome; Disease Progression; Enzymes; Etiology; Family; Fibroblasts; General Population; Genetic; Glutamate-ammonia-ligase adenylyltransferase; Goals; Grant; Housekeeping; Human; Huntington Disease; Huntington gene; Length; Maintenance; Metabolic; Metabolism; Mission; Mitochondria; Modeling; Molecular; Molecular Chaperones; Molecular Target; Nerve Degeneration; Neurons; Niacinamide; Nicotinamidase; Nicotinic Acids; Parkinson Disease; Pathway interactions; Patients; Physical Performance; Proteins; Reporting; Research; Role; Sirtuins; Stimulation of Cell Proliferation; Stress; Structure; Structure-Activity Relationship; System; Testing; Therapeutic Intervention; Toxic effect; Translations; United States Department of Veterans Affairs; Veterans; Yeast Model System; Yeasts; age related; age related neurodegeneration; alpha synuclein; cognitive performance; efficacy study; enzyme pathway; fly; healthspan; in vivo; induced pluripotent stem cell; interdisciplinary approach; misfolded protein; mouse model; neuron loss; neuroprotection; nicotinamide phosphoribosyltransferase; nicotinamide-beta-riboside; nicotinate; nicotinate mononucleotide; novel; novel therapeutic intervention; overexpression; polyglutamine; postmitotic; preclinical efficacy; prevent; protein misfolding; proteostasis; proteotoxicity; recruit; resistance mechanism; stem cell differentiation; synucleinopathy; tool; yeast protein

One of the major challenges for the U.S. Department of Veterans Affairs is to extend the health-span of the veterans and their families as their physical and/or cognitive performance capabilities decline with age. Human neurodegenerative protein misfolding disorders or proteinopathies, are associated with abnormal protein depositions in brain neurons. They include polyglutamine (polyQ) disorders such as Huntington's disease and α-synucleinopathies such as Parkinson's disease. Disclosing the basic molecular and metabolic alterations that occur during aging of post-mitotic cells such as neurons, under proteotoxic stress is crucial for understanding the etiology of neuro-proteinopathies. Metabolic and mitochondrial alterations are hallmarks of aging and neurodegeneration. Over the last decade, we and others have shown that enhancement of mitogenesis or overexpression of NMNAT/NMA1, an enzyme in the Nicotinic acid/Nicotinamide Salvage NAD+ biosynthetic pathway, act as powerful suppressor of proteotoxicities in yeast, fly and mouse models. Through screens in yeast models we identified three additional enzymes of the NAD+ biosynthetic salvage pathway with a role in proteostasis: NADS/Qns1, NaPTRase/Npt1 and NDase/Pnc1. Our observations suggest the existence of an evolutionarily conserved strategy of `repurposing' (or `moonlighting') housekeeping enzymes under stress conditions. Under proteotoxic stress, the four proteins are recruited as molecular chaperones with holdase and foldase activities. In yeast cells, the NAD+ salvage proteins act by preventing misfolding and, together with the Hsp90 chaperone, promoting the refolding of extended polyQ domains or α-synuclein. Their catalytic function is not required for their chaperone role. Preliminary studies in human neuronal models of HD have shown that the human proteins conserve similar “moonlighting” functions and the capacity to protect against proteotoxic stress. We now propose to address the fundamental problem of the intricate interaction between metabolic and cellular protein homeostasis pathways in human neurons. Some of our studies will continue exploiting the yeast model to perform structure-function relationship studies to disclose the domains involved in the chaperone function of the four yeast proteins. We will also continue using yeast models of HD to screen for suppressors among the Nicotinamide Riboside Salvage NAD+ biosynthetic pathway enzymes. An essential component of our studies is the translation of the results previously obtained in yeast to HD patient-derived neurons and HD mouse models. Two neuronal culture systems will be used to test different aspects of disease progression: HD patient-derived induced pluripotent stem cells (iPSCs) differentiated into neurons and HD patient-derived neurons through direct conversion of fibroblasts. A mouse model expressing full-length huntingtin will be used for pre-clinical efficacy studies in vivo. We hypothesize that mitochondrial biogenesis- and NAD+ -biosynthetic-protein pathways act additively to promote energetic stability and maintain proteostasis, respectively, and in this way, protect HD neurons against death. Identifying and characterizing independent yet synergistic pathways of neuroprotection will reveal the complex network for neuroprotection and the intricate relationship between metabolism and neurodegeneration. The proposed research may lead to novel therapeutic approaches to modulate these pathways to counteract cellular toxicities and extend health-span. Finally, the ability to control stress-resistance mechanisms such as those against proteotoxic stress may provide molecular targets and tools to treat the Veterans and the general population to enhance their physical and cognitive performance and postpone their progressive deterioration with age.

美国退伍军人事务部面临的主要挑战之一是延长退伍军人的健康寿命 退伍军人及其家人的身体和/或认知能力下降 人类神经退行性蛋白质错误折叠疾病或蛋白质病与年龄有关。 大脑神经元中的异常蛋白质沉积包括多聚谷氨酰胺 (polyQ) 疾病，例如 亨廷顿病和 α-突触核蛋白病，例如帕金森病。 有丝分裂后细胞（例如神经元）老化过程中发生的分子和代谢变化，在 蛋白毒性应激对于理解神经蛋白病的病因至关重要。 代谢和线粒体改变是衰老和神经退行性疾病的标志。 过去十年，我们和其他人已经证明，有丝分裂的增强或过度表达 NMNAT/NMA1 是烟酸/烟酰胺补救 NAD+ 生物合成途径中的一种酶，可发挥作用 通过酵母筛选，作为酵母、果蝇和小鼠模型中蛋白质毒性的强大抑制剂。 在模型中，我们确定了 NAD+ 生物合成补救途径的另外三种酶，它们在 蛋白质稳态：NADS/Qns1、NaPTRase/Npt1 和 NDase/Pnc1 的存在。 “重新利用”（或“兼职”）管家酶的进化保守策略 在蛋白质毒性应激下，四种蛋白质被招募为分子。 在酵母细胞中，NAD+ 补救蛋白具有保持酶和折叠酶活性。 防止错误折叠，并与 Hsp90 伴侣一起促进延伸的重折叠 PolyQ 结构域或 α-突触核蛋白。它们的催化功能并不是其伴侣作用所必需的。 HD 人类神经模型的初步研究表明，人类蛋白质保存 类似的“兼职”功能和抵御蛋白毒性应激的能力。 我们现在建议解决各个领域之间错综复杂的相互作用的根本问题。 我们的一些研究将研究人类神经元的代谢和细胞蛋白质稳态途径。 继续利用酵母模型进行结构-功能关系研究以揭示 涉及四种酵母蛋白的伴侣功能的结构域我们还将继续使用酵母。 HD 模型用于筛选烟酰胺核苷 Salvage NAD+ 生物合成中的抑制剂 我们研究的一个重要组成部分是先前结果的翻译。 在酵母、HD 患者来源的神经元和 HD 小鼠模型中获得的两种神经元培养系统。 将用于测试疾病进展的不同方面：HD患者来源的诱导多能 干细胞 (iPSC) 通过直接分化为神经元和 HD 患者来源的神经元 表达全长亨廷顿蛋白的小鼠模型将用于临床前研究。 我们进行了线粒体生物发生和 NAD+ 生物合成蛋白的体内功效研究。 途径分别起到促进能量稳定性和维持蛋白质稳态的作用，并且 这样，可以保护 HD 神经元免遭死亡。 识别和表征独立但协同的神经保护途径将 揭示神经保护的复杂网络以及新陈代谢和 拟议的研究可能会带来新的调节治疗方法。 这些途径可以抵消细胞毒性并延长健康寿命。最后，控制能力。 抗应激机制，例如对抗蛋白毒性应激的机制可能提供分子靶标 以及治疗退伍军人和普通大众的工具，以增强他们的身体和认知能力 并延缓其随着年龄的增长而逐渐恶化。