Investigating the Lysosome and Plasma Membrane Systems in Protecting Cells Against Age-induced Amino Acid Toxicity

研究溶酶体和质膜系统保护细胞免受年龄诱导的氨基酸毒性的作用

• 批准号: 10680314
• 负责人: Kevin Chui
• 金额: $ 3.86万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10680314
• 关键词: Acidity; Affect; Age; Aging; Alzheimer' s Disease; Alzheimer' s disease model; Amino Acid Transporter; Amino Acids; Amyloid beta-Protein; Area; Biological Assay; Biological Availability; Calcium ion; Catabolism; Cell Aging; Cell Survival; Cell membrane; Cell physiology; Cells; Cellular Metabolic Process; Collaborations; Cysteine; Cytoplasm; Cytoprotection; Development; Disease; Down-Regulation; Drug Targeting; Endocytosis; Endoplasmic Reticulum; Event; Functional disorder; Genes; Goals; Growth; Haploidy; Healthcare; Homeostasis; Human; Incidence; Individual; Inductively Coupled Plasma Mass Spectrometry; Iron; Link; Longevity; Lysosomes; Malignant Neoplasms; Measures; Mediating; Membrane Transport Proteins; Metabolism; Microscopy; Mitochondria; Multivesicular Body; Nature; Nutrient; Organelles; Oxidative Phosphorylation; Parkinson Disease; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Pilot Projects; Play; Process; Proteins; Proteome; Reactive Oxygen Species; Regulation; Research; Role; Saccharomyces cerevisiae; Saccharomycetales; Science; Signal Transduction; Site; Structure; Supplementation; System; Telomere Shortening; Testing; Toxic effect; Vacuole; Western Blotting; Yeast Model System; Yeasts; abeta toxicity; age related; cell age; cell growth; deletion library; effective therapy; experimental study; innovation; lipid metabolism; lysosome membrane; macromolecule; mitochondrial dysfunction; mutant; novel; response; tool; trafficking; uptake; vacuolar H+-ATPase

Project Summary The incidence of age-related diseases such as Alzheimer’s disease and Parkinson’s disease continues to increase as human lifespan continues to increase. Advancements in science and healthcare have resulted in effective therapies for many diseases but treatments for these debilitating diseases remain elusive. Many studies on aging focus on the dysfunction of basic cellular processes, or the hallmarks of aging. These include mitochondrial dysfunction, abnormal nutrient signaling, telomere shortening, amongst many others. We recently found that lysosomal (vacuole in yeast) deacidification is an early event in aging and precedes mitochondrial dysfunction. Vacuole deacidification results in a loss of amino acid compartmentalization, particularly cysteine, and this results in mitochondrial dysfunction. Amino acid restriction or supplementation with iron rescued mitochondrial function. These previous findings demonstrate the importance of the vacuole in amino acid homeostasis and aging. It should be noted that vacuole deacidification is a gradual process in aging and there are likely systems that collaborate with the vacuole in maintaining cellular homeostasis. Thus, we performed a screen to determine what genes are conditionally essential upon vacuole deacidification. We uncovered genes involved in the ESCRT/MVB pathway as essential under these conditions. Furthermore, we also found several genes involved in endocytosis to be conditionally essential too. The ESCRT pathway is a cellular trafficking pathway that allows for the remodeling of the plasma membrane (PM) proteome, especially nutrient transporters. When transporters are endocytosed, the ESCRT pathway recognizes ubiquitylated transporters and directs them to the vacuole for degradation. The known function of the ESCRT pathway in conjunction with the vacuole’s role in amino acid compartmentalization raises the idea that these two systems collaborate in maintaining cellular amino acid homeostasis during the aging process. This is supported by our pilot study showing that amino acid transporters (AATs) are indeed endocytosed upon vacuole deacidification. By using the budding yeast Saccharomyces cerevisiae, we will determine how amino acid uptake and metabolite pools are affected under conditions of vacuole deacidification. Furthermore, we will elucidate the signal that originates from dysfunctional vacuoles that triggers AAT endocytosis and turnover. Finally, we will test the hypothesis that Aβ inhibits ESCRT- mediated turnover of AATs and inhibits cell growth by causing amino acid toxicity. Aging remains an active field of research but how the ESCRT pathway cooperates with the vacuole in the context of aging is understudied. Furthermore, how Aβ expression affects cellular amino acid homeostasis is understudied. The goal of this proposal is to elucidate a novel mechanism for cellular aging and increase our understanding of the pathogenesis of Alzheimer’s disease.

项目概要 阿尔茨海默病和帕金森病等与年龄相关的疾病的发病率持续上升 随着人类寿命的不断延长，科学和医疗保健的进步导致了。 对许多疾病有有效的治疗方法，但对这些使人衰弱的疾病的治疗方法仍然难以捉摸。 关于衰老的研究重点是基本细胞过程的功能障碍，或衰老的特征，其中包括。 线粒体功能障碍、营养信号异常、端粒缩短等。 发现溶酶体（酵母中的液泡）脱酸是衰老的早期事件，并且先于线粒体 液泡脱酸导致氨基酸区室化的丧失，特别是半胱氨酸， 这会导致线粒体功能障碍，或者通过补充铁来挽救。 这些先前的发现证明了液泡在氨基酸中的重要性。 应该指出的是，真空脱酸是一个渐进的老化过程。 可能是与液泡协作维持细胞稳态的系统。 筛选以确定真空脱酸时条件必需的基因。 此外，我们还发现了一些在这些条件下参与 ESCRT/MVB 途径的重要因素。 参与内吞作用的基因也是有条件必需的。ESCRT 途径是一种细胞运输。 允许质膜（PM）蛋白质组重塑的途径，特别是营养转运蛋白。 当转运蛋白被内吞时，ESCRT 途径会识别泛素化转运蛋白并指导它们 已知的 ESRT 通路功能与真空的作用相结合。 氨基酸区室化提出了这样的想法：这两个系统协同维持细胞 我们的初步研究表明氨基酸在衰老过程中保持稳态。 通过使用芽殖酵母，转运蛋白（AAT）确实在真空脱酸后被内吞。 酿酒酵母，我们将确定氨基酸摄取和代谢物池在以下情况下如何受到影响 此外，我们将阐明源自功能失调的信号。 最后，我们将检验 Aβ 抑制 ESCRT- 的假设。 介导 AAT 的周转并通过引起氨基酸毒性抑制细胞生长仍然是一个活跃的领域。 但在衰老背景下 ESCRT 通路如何与真空配合的研究还不够。 此外，Aβ 表达如何影响细胞氨基酸稳态尚未得到充分研究。 提案旨在阐明细胞衰老的新机制并增加我们对其发病机制的了解 阿尔茨海默病。