Selective neuronal autophagy in phosphorylated tau degradation and Alzheimer's disease

选择性神经元自噬在磷酸化 tau 降解和阿尔茨海默病中的作用

• 批准号: 10675192
• 负责人: Zachary Mark Augur
• 金额: $ 4.17万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10675192
• 关键词: Adaptor Signaling Protein; Address; Affect; Aging; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease pathology; Alzheimer' s disease patient; Amino Acids; Amyloid beta-Protein; Autophagocytosis; BAG3 gene; BCL1 Oncogene; Biological Assay; Bortezomib; Brain; CRISPR/Cas technology; Clinical; Compensation; Data; Dementia; Exposure to; Genetic; Homeostasis; Human; Impaired cognition; Individual; Induced pluripotent stem cell derived neurons; Knock-out; Late Onset Alzheimer Disease; Mass Spectrum Analysis; Measures; Mediating; Memory; Modality; Molecular; Molecular Chaperones; Nerve Degeneration; Neurofibrillary Tangles; Neurons; Physiologic pulse; Physiological; Play; Predisposition; Proteasome Inhibitor; Proteins; Proteomics; Protocols documentation; Regulation; Reporter; Risk; Role; Senile Plaques; Stable Isotope Labeling; System; TBK1 gene; Ubiquitin; Western Blotting; Work; cohort; excitatory neuron; extracellular; hyperphosphorylated tau; interest; knock-down; multi-electrode arrays; multicatalytic endopeptidase complex; neuropathology; neurotoxic; new therapeutic target; novel therapeutics; protein activation; protein aggregation; protein degradation; proteostasis; religious order study; response; small hairpin RNA; targeted treatment; tau Proteins; tau aggregation; tau-1

Project Summary/Abstract: Alzheimer’s disease (AD) pathology is defined by aberrant protein aggregation of extracellular amyloid- beta plaques and intracellular hyperphosphorylated tau tangles within the brain, resulting in progressive cognitive decline. However, a plethora of amyloid-beta targeting therapies have yielded limited clinical benefit, lending credence to the significance of tau aggregation in AD. Specifically, the protein degradation network, which includes the autophagy-lysosomal system (autophagy) and the ubiquitin-proteasome system (UPS), is frequently cited as deficient in AD, and may therefore affect neurodegeneration and intracellular tau protein clearance within the brain. To investigate the mechanisms of selective protein degradation in neuronal proteostasis and AD I will use an induced pluripotent stem cell (iPSC)-derived neuronal system (iNs). Specifically, our lab has generated over 50 human iN lines from the Religious Order Study and Rush Memory and Aging Project (ROSMAP) cohorts which represent the full clinical and neuropathological spectrum of late onset AD. Across these genetically diverse iNs, we previously assayed basal autophagic flux and UPS capacity. Additionally, proteomic analysis and western blotting of these same iNs revealed strong associations between phosphorylated tau species and proteins relevant in selective autophagy of protein aggregates (aggrephagy). Of particular interest is the ubiquitin-dependent aggrephagy adaptor protein, optineurin (OPTN), which displays the most significant negative correlation with aggregated phospho-tau forms relevant in our AD neurons. BCL-2-associated athanogene 3 (BAG3) is another relevant aggrephagy chaperone protein that has previously been associated with tau homeostasis within excitatory neurons and shows a strong compensatory relationship upon UPS inhibition in our human neuronal system. Therefore, I hypothesize that AD derived neurons have a diminished capacity for protein degradation activation following exposure to AD relevant neurotoxic proteins and genetic modulation of autophagy, which results in an accumulation of phospho-tau and a reduction in neuronal activity. To address this hypothesis, I have two aims: 1) To determine the influence of OPTN regulation on neuronal tau proteostasis and neuronal function. To this end I will expose both AD and non-AD iNs to brain extract containing neurotoxic proteins and measure several forms of tau and neuronal firing. 2) To investigate the role of BAG3- mediated chaperone-assisted selective autophagy in modulating protein degradation compensation in human neurons. Here, I will modulate BAG3 expression in both AD and non-AD iNs and expose these iNs to AD brain extract containing neurotoxic proteins. I then will measure tau accumulation, neuronal firing, and protein turnover. Taken together, the findings of this proposal will not only further the understanding of tau protein degradation via aggrephagy but will define the molecular mechanisms governing OPTN and BAG3 regulation and function in neurons and may lead to novel therapeutic modalities.

项目摘要/摘要： 阿尔茨海默氏病（AD）病理是通过细胞外淀粉样蛋白异常聚集来定义的 β斑块和细胞内的高磷酸化tau缠结在大脑内，导致进行性认知 衰退。但是，大量淀粉样β靶向疗法的临床益处有限，贷款 对tau汇总在AD中的重要性的信誉。具体而言，蛋白质降解网络，该网络 包括自噬溶质体系统（自噬）和泛素 - 蛋白酶体系统（UPS），通常是 被引用为AD不足，因此可能影响神经退行性变性和细胞内TAU蛋白清除率 大脑。研究神经元蛋白抑制剂中选择性蛋白质降解的机制，AD I将 使用诱导的多能干细胞（IPSC）衍生的神经元系统（INS）。具体来说，我们的实验室已经生成 宗教秩序研究与繁荣记忆和衰老项目（ROSMAP）同伙的50多人 代表了晚期AD的完整临床和神经病理学谱。一般而言 多样化，我们以前分配了基本的自噬通量和UPS容量。另外，蛋白质组学分析 这些相同INS的蛋白质印迹揭示了磷酸化的tau物种与 蛋白质与蛋白质聚集体的选择性自噬相关（凝集）。特别感兴趣的是 泛素依赖性的凝集衔接蛋白Optineurin（Optn），显示最显着的 与我们的AD神经元相关的综合磷酸-TAU形式的负相关。 Bcl-2相关 Athanogene 3（BAG3）是另一种相关的杂色伴侣蛋白，以前已关联 在兴奋性神经元内使用tau稳态，并显示了UPS的牢固的补偿关系 在我们的人类神经元系统中抑制。因此，我假设AD衍生的神经元有所减少 暴露于AD相关神经毒性蛋白和遗传的蛋白质降解激活的能力 自噬的调节，导致磷酸-TAU的积累和神经元活性的降低。 为了解决这一假设，我有两个目的：1）确定OPTN调控对神经元的影响 蛋白质和神经元功能。为此，我将公开AD和非AD INS 神经毒性蛋白质和测量几种形式的tau和神经元放电。 2）调查Bag3-的作用 介导的伴侣辅助选择性自噬在调节人类的蛋白质降解补偿中 神经元。在这里，我将在AD和非AD中调节Bag3表达，并将这些ins暴露于AD大脑中 含有神经毒性蛋白的提取物。然后，我将测量tau的积累，神经元放电和蛋白质更新。 综上 敏锐的 神经元并可能导致新型的热方式。