The Role of Ubiquitination in Tau Oligomers Pathogenesis

泛素化在 Tau 寡聚体发病机制中的作用

基本信息

批准号：
10605268
负责人：
Rakez Kayed
金额：
$ 74.83万
依托单位：
UNIVERSITY OF TEXAS MED BR GALVESTON
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-15 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10605268
关键词：
Address Affect Alzheimer&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos s disease therapy American Amino Acids Appearance Astrocytes Binding Biochemical Biological Markers Brain region C-terminal Cell Culture Techniques Cells Deubiquitination Disease Disease Progression Economic Burden Exhibits Functional disorder Goals Human Impaired cognition In Vitro Isotope Labeling Knowledge Lysine MAPT gene Mass Spectrum Analysis Mediating Microglia Microtubules Modeling Modification Molecular Monoubiquitination Multivesicular Body Mus Neurodegenerative Disorders Neurofibrillary Tangles Neurons Pathogenesis Pathologic Pathology Pathway interactions Pattern Phosphorylation Physiological Polyubiquitination Population Post-Translational Protein Processing Process Proteins Proteomics Regulation Reporting Research Design Role Series Signal Transduction Site-Directed Mutagenesis Stable Isotope Labeling Synapses Synaptic Transmission System Tauopathies Testing Therapeutic Toxic effect Ubiquitin Ubiquitination brain cell cognitive function extracellular hTau Mice in vivo multicatalytic endopeptidase complex neuroinflammation neurotoxic neurotoxicity new therapeutic target non-demented novel novel therapeutic intervention prevent prion-like proteostasis socioeconomics tau Proteins tau aggregation trafficking ubiquitin isopeptidase ubiquitin-protein ligase

项目摘要

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder imposing an unbearable socio- economic burden worldwide. Current therapeutic approaches fail to halt AD progression, indicating the need for new strategies, which is the focus of this project. Neurofibrillary tangles (NFTs)–the major pathological hallmark in human AD and related tauopathies, occurs when microtubule-associated protein tau (MAPT or tau) forms aggregates. Further, accumulation of the tau aggregates in AD brain promotes cognitive decline, accompanied with dysregulated proteostasis in neurons. However, we and others have previously shown that smaller soluble tau-aggregates, called oligomers, are the most toxic species and form prior to NFTs in human AD. Our preliminary studies show that AD-brain-derived tau oligomers (BDTOs) exhibit unique post-translational modifications (PTMs), including specific ubiquitin-linkages, which seem to be involved in tau-aggregation that influence stability, propagation in a prion-like manner and subsequent cognitive decline. Understanding the fundamental signature ubiquitination pattern by which tau oligomers evade proteasomal degradation and promote its assembly, stability, secretion and propagation is important for developing disease-modifying therapies for AD. This proposal will test the central hypothesis that the unique mono-ubiquitination of tau oligomers facilitate to evade the neuronal ubiquitin-proteasome system (UPS), and promote its accumulation in neurons, which causes synaptic dysfunction. Furthermore, these tau oligomers contribute to increased neuronal toxicity, secretion and propagation of a prion-like tau pathology, and also promote neuroinflammation by modulating microglia and astrocytes activation. In specific aim 1, using mass-spectroscopy and site-directed mutagenesis, we will define the mechanism and functional impact of lysine modification, and particularly reversible mono- ubiquitination, in regulating the processing, assembly and trafficking of tau oligomers in neurons. This will also define the biochemical and structural consequences of tau oligomer mono-ubiquitination in modulating the efficacy of tau oligomer assembly, secretion and propagation in AD, which will serve as a potential AD antemortem biomarker, and provide key information for targeting the pathological tau. Using isotope labeling by amino acids in vitro and in vivo (SILAC) proteomics approaches, in specific aim 2, we will define the mechanism by which mono-ubiquitination controls the interplay between PHF-tau assembly and tau oligomers secretion and propagation in primary neurons. Further, physiological mechanisms for regulation of tau-deubiquitination and AD pathogenesis will be verified using complementary approaches. In specific aim 3, we will investigate the role of deubiquitinase Otub1 on tau oligomer accumulation, trafficking and self-propagation in neurons.

阿尔茨海默病 (AD) 是最常见的神经退行性疾病，给社会带来难以忍受的痛苦目前的治疗方法无法阻止 AD 的进展，这表明需要治疗。新策略，这是该项目的重点——神经原纤维缠结（NFT）——主要的病理标志。在人类 AD 和相关 tau 病中，当微管相关蛋白 tau（MAPT 或 tau）形成时发生此外，AD 大脑中 tau 蛋白聚集物的积累会导致认知能力下降。然而，我们和其他人之前已经表明，较小的可溶性。 tau 聚集体，称为寡聚物，是人类 AD 中毒性最强的物种，其形成早于 NFT。初步研究表明 AD 脑源性 tau 寡聚体 (BDTO) 表现出独特的翻译后活性修饰（PTM），包括特定的泛素连接，这些连接似乎与 tau 聚集有关影响稳定性、以类似朊病毒的方式传播以及随后的认知能力下降。 tau 寡聚体逃避蛋白酶体降解的基本特征泛素化模式促进其组装、稳定性、分泌和繁殖对于开发疾病修饰非常重要 AD 的治疗方法。该提案将检验中心假设，即 tau 寡聚体独特的单泛素化有助于逃避神经元泛素蛋白酶体系统（UPS），并促进其在神经元中的积累，从而此外，这些 tau 寡聚体会导致神经元毒性增加，朊病毒样 tau 蛋白病理学的分泌和传播，并通过调节促进神经炎症小胶质细胞和星形胶质细胞的激活在具体目标 1 中，使用质谱和定点诱变，我们将定义赖氨酸修饰的机制和功能影响，特别是可逆单修饰泛素化，调节神经元中 tau 寡聚体的加工、组装和运输。定义 tau 寡聚体单泛素化在调节 tau 寡聚体组装、分泌和传播在 AD 中的功效，这将作为潜在的 AD 死前生物标志物，并通过同位素标记提供靶向病理性 tau 蛋白的关键信息。氨基酸体外和体内 (SILAC) 蛋白质组学方法，在具体目标 2 中，我们将定义其机制通过单泛素化控制 PHF-tau 组装和 tau 寡聚体分泌之间的相互作用此外，tau 去泛素化和 AD 调节的生理机制。在具体目标 3 中，我们将使用补充方法来验证发病机制。去泛素酶 Otub1 对神经元中 tau 寡聚体积累、运输和自我繁殖的影响。