Presenilin 1 Modulates Lysosome Function and Tau Degradation

Presenilin 1 调节溶酶体功能和 Tau 降解

• 批准号: 10368913
• 负责人: Carol Ann Deaton
• 金额: $ 5.1万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10368913
• 关键词: Address; Affect; Age of Onset; Aging; Alzheimer' s Disease; Antibodies; Autophagocytosis; Autophagosome; Axon; BODIPY; Binding; Biology; Catalytic Domain; Cathepsins; Cell membrane; Characteristics; Complex; Data; Defect; Degradation Pathway; Dendrites; Endosomes; Event; Exhibits; Functional disorder; Genes; Health; Immunoblotting; Impairment; Knowledge; Light; Lysosomes; Measures; Mediating; Monitor; Multivesicular Body; Mutate; Mutation; Neurobiology; Neurodegenerative Disorders; Neurons; Pathogenicity; Pepstatins; Peptide Hydrolases; Peptides; Play; Presenile Alzheimer Dementia; Process; Production; Proteins; Proton Pump; Rattus; Recycling; Reporting; Role; Supervision; Synaptosomes; Testing; Vesicle; exosome; extracellular; familial Alzheimer disease; gamma secretase; immunocytochemistry; inhibitor/antagonist; innovation; knock-down; live cell imaging; mutant; optogenetics; overexpression; postsynaptic; presenilin-1; proteostasis; secretase; small hairpin RNA; tau Proteins; tau aggregation; tau expression; tau-1; trafficking; vector

A common feature of Alzheimer’s disease (AD), as well as other older age onset neurodegenerative diseases, is the accumulation of misfolded, abnormally modified proteins. In AD, aggregates of tau are a classical hallmark. A significant contributing factor to the formation of these proteinaceous accumulations is dysfunction of the lysosome-dependent degradative pathways. Interestingly, the majority of autosomal dominant familial AD (FAD) cases are caused by mutations in presenilin 1 (PS1), the catalytic subunit of the  secretase complex, which also likely facilitates lysosomal function. However, the role of PS1 in mediating lysosome biology and the clearance of tau has not been fully delineated. Given previous studies and our preliminary data, the UNDERLYING PREMISE of this proposal is that in neurons PS1 plays a fundamental role in regulating the function of lysosomes and, thus, tau turnover. Lysosomes play a key role in maintaining proteostasis as multiple degradative pathways direct their cargos to the lysosome for degradation/recycling. Alterations in the activity or intracellular localization of lysosomes contribute to the pathogenic processes of these neurodegenerative diseases. Given the importance of lysosome function to neuron health, understanding how PS1 impacts lysosome biology is of high importance. CRITICAL KNOWLEDGE GAPS include: how depletion of PS1 in primary neurons impacts lysosome pH, the effects of PS1 depletion on autophagosome-lysosome and endosome-lysosome fusion, the impact of PS1 depletion on tau turnover and how re-acidification of lysosomes in neurons with PS1 depleted affects the PS1-induced lysosomal fusion defects and deficiencies in tau turnover. Considering these critical knowledge gaps the OVERALL HYPOTHESIS is that depletion of PS1 leads to impairment of lysosome function, localization and fusion events, which negatively impact tau clearance. In the context of this overall hypothesis, the specific aims of this proposal are to test the hypotheses: (1) that PS1 plays a role in the acidification, activity, and localization of lysosomes and other degradative vesicles within different neuronal compartments and (2) that vesicle- mediated processing/clearance and intraneuronal localization of tau is impaired by knockdown of PS1. These studies will be carried out using primary rat cortical neuron cultures. Overall this a transformative project that addresses significant gaps in our scientific knowledge. The proposal is innovative in conceptualizing PS1 as a key regulator of lysosome function and thus a significant contributor to proteostasis in general and tau more specifically. Further, technically it is innovative as we will be using an optogenetically driven proton pump to decrease the pH of lysosomes after PS1 knockdown to determine if maintaining an acidified lysosome is sufficient to restore its function. The IMPACT of these studies will be a significant contribution to our understanding of the role of PS1 in regulating tau biology via lysosomal function, thus informing general perspectives of neurobiological degeneration in aging. .

阿尔茨海默氏病（AD）以及其他年龄较大的神经退行性疾病的共同特征， 是错误折叠的，否则修改的蛋白质的积累。在广告中，tau的骨料是经典 标志。这些蛋白质积累的形成的重要因素是功能障碍 溶酶体依赖性降解途径的。有趣的是，大多数常染色体主导家庭 AD（FAD）病例是由Presenilin 1（PS1）突变引起的，泌尿酶的催化亚基 复合物，这也可能是最爱的溶酶体功能。但是，PS1在介导溶酶体中的作用 生物学和tau的清除尚未完全描述。鉴于先前的研究和我们的初步 数据，该提案的基本前提是，在神经元中，PS1在 调节溶酶体的功能，从而调节TAU周转率。溶酶体在维持 蛋白质症作为多种降解途径，将其货物引导到溶酶体降解/回收。 溶酶体活性或细胞内定位的改变有助于致病过程 这些神经退行性疾病。鉴于溶酶体功能对神经元健康的重要性， 了解PS1如何影响溶酶体生物学非常重要。批判知识差距 包括：原发性神经元中PS1的耗竭如何影响溶酶体pH，PS1部署对 自噬体 - 莱斯体和内体 - 莱斯体融合，PS1部署对TAU周转和 PS1耗尽的神经元中溶酶体的重新循环如何影响PS1诱导的溶酶体融合 TAU周转率的缺陷和缺陷。考虑这些关键知识的整体差距 假设是PS1的耗竭会导致溶酶体功能，定位和融合的损害 事件，对tau的清除产生负面影响。在这个总体假设的背景下，这是特定的目的 建议是测试假设：（1）PS1在酸化，活性和定位中起作用 不同神经元室内的溶酶体和其他降解蔬菜，（2）蔬菜 - pS1的敲低会损害tau的介导的加工/清除率和神经元定位。这些 研究将使用原发性大鼠皮质神经元培养物进行。总的来说，这是一个变革性的项目 解决我们科学知识中的重大差距。该提案在将PS1概念化为一个创新 溶酶体功能的关键调节剂，因此总体上是蛋白质抗体的重要促进者，而tau则更多 此外，从技术上讲，它具有创新性，因为我们将使用光学驱动的质子泵 降低PS1敲低后溶酶体的pH值，以确定维持酸化的溶酶体是否为 足以恢复其功能。这些研究的影响将是对我们的重要贡献 通过溶酶体功能了解PS1在调节Tau生物学中的作用，从而通知一般 衰老中神经生物学变性的观点。 。