Isoform-dependent effects of tau phosphorylation in Alzheimer's disease

阿尔茨海默病中 tau 磷酸化的异构体依赖性效应

• 批准号: 10745286
• 负责人: Nima Nick Naseri
• 金额: $ 7.18万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10745286
• 关键词: Acceleration; Address; Adult; Affect; Affinity; Age; Aging; Alternative Splicing; Alzheimer' s Disease; Alzheimer' s disease model; Alzheimer' s disease patient; Behavior; Binding; Biological Assay; Biology; Biophysics; Brain; Cells; Charge; Chemicals; Chemistry; Complement; Data; Dementia; Development; Dimensions; Disease; Disease Progression; Dissociation; Doctor of Philosophy; Embryo; Embryonic Development; FTD with parkinsonism; Fetal Tissues; Fluorescence; Functional disorder; Future; Goals; Grant; Heterogeneity; Hippocampus; Impairment; In Vitro; Injections; Lead; Length; Link; MAPT gene; Measures; Microtubule Polymerization; Microtubule Stabilization; Microtubules; Molecular Conformation; Mus; Mutate; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Neurosciences; Pathologic; Pathology; Pattern; Phosphorylation; Phosphorylation Site; Play; Positioning Attribute; Protein Biosynthesis; Protein Isoforms; Proteins; Research Personnel; Resolution; Role; Science; Site; Solubility; Spectrum Analysis; Structure; Tauopathies; Techniques; Testing; Total Internal Reflection Fluorescent; Training; Transgenic Mice; Tubulin; Tubulin Interaction; age related; aging brain; biophysical techniques; chemical synthesis; driving force; experimental study; fetal; gain of function; hyperphosphorylated tau; in vivo; insight; mouse model; nervous system disorder; neuropathology; novel; peptide chemical synthesis; post-doctoral training; proteostasis; single molecule; single-molecule FRET; skills; tau Proteins; tau aggregation; tau function; tau mutation; tau-1; tool

Neuropathology of the microtubule-associated protein tau is central to numerous devastating neurological disorders termed tauopathies, including Alzheimer's disease (AD). Tau promotes microtubule (MT) polymerization and stability via its interaction with tubulin, regulated by phosphorylation to tau in multiple domains. Six major tau isoforms are alternatively spliced in an age-dependent manner. While FTDP-17-causing mutations in tau show isoform-dependent effects on aggregation and microtubule stabilization, there are no tau mutations linked to AD. Meanwhile, isoform-dependent effects of phosphorylation to tau remain unexplored. Interestingly, I discovered that numerous AD-relevant phospho-tau (pTau) sites are also phosphorylated during normal embryonic development, and then decrease over age. Why are specific pTau sites, which are correlated with disease, also expressed during normal development? The parallel between the developmental and pathological states suggests that understanding the function of pTau during development would elucidate the mechanism(s) underlying tau pathology in AD. My preliminary data indicate that i) numerous AD-relevant pTau sites are expressed in normal embryonic mouse brains, ii) pTau is soluble and likely functional in fetal tissue, iii) phosphorylation at sites T231, S235 and S262 impair MT polymerization by the fetal tau isoform but not an adult isoform, and iv) these same pTau sites accelerate aggregation of the adult isoform over the fetal isoform. Recent evidence demonstrates that tau initiates nucleation of MT polymerization. Based on my preliminary data, ! propose that tau phosphorylation has isoform-dependent effects, in which specific pTau sites are detrimental to adult isoforms in an aging brain but functional in the fetal isoform in developing brains. I will explore two aims which will provide critical insight to understanding the effects of tau phosphorylation in each isoform. In Aim 1, I will determine the relationship between the interaction between pTau with both soluble tubulin and stabilized MTs in each isoform. In Aim 2, I will test for the relationship between pTau sites which cause tau to dissociate from MTs with those that accelerate its aggregation and/or seeding activity. Importantly, our lab has uniquely synthesized full-length tau with genuine chemical phosphorylation at sites T231, S235 and S262 for these studies. These experiments will be tested using multiple platforms including these chemically-synthesized proteins, high-resolution single-molecule techniques (single-molecule FRET, fluorescence correlative spectroscopy, and time-lapse TIRF microscopy), and injection of semi-synthesized proteins into mouse brains. The investigator has 6+ years of expertise in working with the biological assays and mouse models described here, and the sponsor and collaborators will guide training in the described chemical and biophysical techniques. I anticipate that my findings will elucidate the function of tau in developing neurons, and will provide insight into mechanisms of pathological tau hyperphosphorylation across numerous tauopathies including AD.

微管相关蛋白tau的神经病理学是许多破坏性神经疾病的中心。 包括阿尔茨海默病(AD)在内的疾病被称为tauopathy。Tau促进微管(MT) 通过与微管蛋白相互作用的聚合和稳定性，受多个 域名。六种主要的tau亚型以年龄相关的方式交替剪接。而FTDP-17-导致 Tau基因突变对聚集和微管稳定有异构体依赖效应，不存在tau基因。 突变与阿尔茨海默病有关。同时，磷酸化对tau的异构体依赖效应仍未被研究。 有趣的是，我发现许多AD相关的磷酸-tau(Ptau)位点在 正常的胚胎发育，然后随着年龄的增长而减少。为什么特定的ptau位点是相关的？ 有疾病的人，在正常发育过程中也会表达吗？发展与发展之间的平行关系 病理状态表明，了解ptau在发育过程中的功能将解释 AD的tau病理基础机制(S)。我的初步数据显示，i)许多与AD相关的ptau Ptau在正常胚胎小鼠脑中表达，ii)ptau在胎儿组织中是可溶的，可能具有功能，iii) T231、S235和S262位的磷酸化抑制胎儿tau亚型的MT聚合，但不影响成人 以及iv)这些相同的ptau位点加速了成人异构体在胎儿异构体上的聚集。近期 证据表明，tau引发了MT聚合的成核作用。根据我的初步数据，！ 提出tau磷酸化具有异构体依赖效应，在这种效应中，特定的ptau位点对 成人亚型在老化的大脑中，但在发育中的脑中在胎儿亚型中起作用。我将探讨两个目标 这将为理解tau磷酸化在每种异构体中的作用提供关键的见解。在目标1中，我 将决定ptau与可溶性微管蛋白和稳定化微管之间的相互作用之间的关系 每一种亚型的MTS。在目标2中，我将测试导致tau解离的ptau位点之间的关系 与那些加速其聚合和/或种子活动的MTS。重要的是，我们的实验室拥有独特的 合成全长tau，并在T231、S235和S262位进行真正的化学磷酸化 学习。这些实验将使用多个平台进行测试，包括这些化学合成的平台 蛋白质，高分辨率单分子技术(单分子FRET，荧光相关 将半合成的蛋白质注射到小鼠大脑中。 研究人员在上述生物检测和小鼠模型方面有6年以上的专业经验。 在这里，赞助商和合作者将指导所述化学和生物物理技术的培训。 我预计我的发现将阐明tau在神经元发育中的作用，并将为深入了解 包括阿尔茨海默病在内的多种tau病的病理性tau过度磷酸化的机制。