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

基本信息

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
项目类别：
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&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease pathology Alzheimer&apos 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

项目摘要

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：阿尔茨海默病 (AD) 病理学的定义是细胞外淀粉样蛋白的异常蛋白质聚集大脑内的β斑块和细胞内过度磷酸化的tau蛋白缠结，导致渐进性认知然而，大量的β-淀粉样蛋白靶向疗法产生的临床益处有限。相信 tau 蛋白聚集在 AD 中的重要性，特别是蛋白质降解网络。包括自噬-溶酶体系统（autophagy）和泛素-蛋白酶体系统（UPS），经常被被认为是 AD 缺陷，因此可能影响神经退行性变和细胞内 tau 蛋白清除为了研究神经元蛋白质稳态和 AD 中选择性蛋白质降解的机制，我将具体来说，我们的实验室已经生成了诱导多能干细胞（iPSC）衍生的神经系统（iNs）。来自宗教秩序研究和 Rush Memory and Aging Project (ROSMAP) 队列的 50 多个人类 iN 系它代表了晚发 AD 的完整临床和神经病理学谱。针对不同的 iN，我们之前测定了基础自噬通量和 UPS 能力，此外还进行了蛋白质组分析。这些相同 iN 的蛋白质印迹揭示了磷酸化 tau 物种与与蛋白质聚集体选择性自噬（aggrephagy）相关的蛋白质特别令人感兴趣。泛素依赖性聚合吞噬衔接蛋白 optineurin (OPTN)，显示出最显着的与 BCL-2 相关神经元中相关的聚集磷酸 tau 形式呈负相关。 athanogene 3 (BAG3) 是另一种相关的吞噬分子伴侣蛋白，之前已被认为与与兴奋性神经元内的 tau 蛋白稳态一致，并在 UPS 上表现出很强的代偿关系因此，我认为 AD 衍生的神经元的抑制作用减弱。暴露于 AD 相关神经毒性蛋白和遗传性蛋白后，蛋白降解激活的能力自噬的调节，导致磷酸 tau 的积累和神经元活动的减少。为了解决这个假设，我有两个目标：1）确定 OPTN 调节对神经 tau 蛋白的影响为此，我将 AD 和非 AD iN 暴露于含有脑提取物的脑提取物中。神经毒性蛋白并测量几种形式的 tau 和神经元放电 2) 研究 BAG3- 的作用。介导的分子伴侣辅助选择性自噬调节人类蛋白质降解补偿在这里，我将调节 AD 和非 AD iN 中的 BAG3 表达，并将这些 iN 暴露于 AD 大脑。然后我将测量含有神经毒性蛋白质的提取物、神经元放电和蛋白质周转。总而言之，该提案的研究结果不仅将进一步加深对 tau 蛋白降解的理解 aggrephagy 但将定义控制 OPTN 和 BAG3 调节和功能的分子机制神经元，并可能导致新的治疗方式。