An in situ Neuronal Model of PHF-TAU Accumulation in AD

AD 中 PHF-TAU 积累的原位神经元模型

• 批准号: 6509809
• 负责人: GARTH F HALL
• 金额: $ 25.44万
• 依托单位: UNIVERSITY OF MASSACHUSETTS LOWELL
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-15 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6509809
• 关键词: Agnatha; Alzheimer's disease; amyloid proteins; cellular pathology; disease /disorder model; disease /disorder proneness /risk; gene expression; gene mutation; genetic disorder; heparan sulfate; human genetic material tag; microtubules; neural degeneration; neurofibrillary tangles; neurogenetics; neurons; nucleic acid sequence; paired helical filament; phosphorylation; protein biosynthesis; protein metabolism; proteoglycan; tau proteins; tissue /cell culture

Paired helical filaments (PHFs) and straight filaments (SFS) make up the neurofibrillary tangles (NFTs) of Alzheimer's Disease (AD) and other neurofibrillary degenerative conditions, where their occurrence is well correlated spatiotemporally with cell loss and dementia. The cellular mechanisms and consequences of tau filament formation are critical pathogenic factors in neurodegenerative conditions featuring NFTs, since neurofibrillary degeneration (NFD) has been shown to be induced by mutations in the tau gene. In AD, it is likely that NFT formation and neurodegeneration are influenced by abnormalities in the metabolism of amyloid precursor protein (APP), which are thought to produce the extracellular beta-amyloid (Abeta) deposits of AD, and initiate AD pathogenesis. However, murine transgenic models which generate mutant APP and/or (Abeta) deposits do not develop tau filaments or NFD, and recently developed tau overexpression transgenics (which do develop NFD) impose significant technical limitations on the elucidation of the cellular mechanisms underlying tau-induced NFD in a given cell type. There is presently only one in situ neuronal model of tau-induced NFD in which the role of extracellular deposits of (Abeta) or any other factor that might affect tau filament formation (such as tau hyperphosphorylation, the presence of intracellular Abeta 1-42, or the binding of heparin to tau) can be readily studied in detail at the single cell level. This is a set of giant identified neurons (ABCs) in the lamprey CNS, which was developed as an NFD cellular model by the PI during the first funding period of this grant. In ABCs, overexpression of human tau via intracellular plasmid injection causes tau filament formation and accumulation, dendritic microtubule loss, synapse loss and eventually neuronal degeneration. The goal of this renewal is to use the ABC cellular model to test directly the relationships between the extent and type of tau filament formation, the state of tau phosphorylation, and the loss of dendritic MTs and synapses caused by human tau expression in vivo by manipulating the following factors during the expression of exogenous human tau in ABCs: C terminal deletions of htau that accelerate or block filament formation in vitro Mutations in tau that have been directly linked to NFD in humans Intracellular levels of heparan sulfate proteoglycans and Abeta 1-42 and extracellular Abeta during htau expression The results of this study should indicate how these manipulations are related to the development of neurofibrillary changes resembling those seen in Abeta and familial tauopathies in single, identified vertebrate central neurons in vivo. Consequently, the proposed studies should lead to fundamental new insights into the cellular mechanisms connecting tau metabolism with NFT formation, the presence of Abeta deposits and the cytopathology of AD and other forms of NFD that are presently unavailable from studies in cell culture or murine transgenic systems.

成对的螺旋丝（PHF）和直丝（SFS）构成了阿尔茨海默氏病（AD）的神经原纤维缠结（NFT）和其他神经纤维纤维退行性疾病，在这些疾病中，它们的发生与细胞丧失和dementia的时空相关性很好。 Tau细丝形成的细胞机制和后果是具有NFTS的神经退行性疾病的关键致病因素，因为神经原纤维退化（NFD）已被证明是由Tau基因突变引起的。 在AD中，NFT形成和神经退行性可能受到淀粉样蛋白前体蛋白（APP）代谢异常的影响，这些蛋白质（APP）被认为会产生AD的细胞外β-淀粉样蛋白（ABETA）沉积物，并引发AD AD病原体。 但是，产生突变体应用程序和/或（Abeta）沉积物的鼠转基因模型不会产生tau丝或NFD，并且最近开发的TAU过表达转基因（确实开发了NFD）对给定的细胞类型中的tau诱导的NFD的细胞机制施加了显着的技术限制。 目前，只有一种原位神经元模型的NFD的原位神经元模型，其中（Abeta）的细胞外沉积物（Abeta）或任何可能影响Tau细丝形成的任何其他因素（例如Tau高磷酸化，细胞内Abeta 1-42的存在，或Heparin与Heparin与Tau的结合）的作用可以读取单个单元格的级别。 这是Lamprey CNS中的一组巨型鉴定的神经元（ABC），在该赠款的第一个资助期间，PI是由PI开发的。 在ABC中，通过细胞内质粒注射对人TAU的过表达会导致Tau细丝形成和积累，树突小管损失，突触丧失以及最终的神经元变性。 The goal of this renewal is to use the ABC cellular model to test directly the relationships between the extent and type of tau filament formation, the state of tau phosphorylation, and the loss of dendritic MTs and synapses caused by human tau expression in vivo by manipulating the following factors during the expression of exogenous human tau in ABCs: C terminal deletions of htau that accelerate or block filament formation in vitro在HTAU表达期间，TAU中与NFD直接相关的TAU的突变与人类细胞内硫酸盐蛋白聚糖和Abeta 1-42和Abeta 1-42和Abeta的突变在HTAU表达过程中，这项研究的结果应表明这些操纵与神经纤维中的Neurofibrillons变化相关，并在Abate Neurons中鉴定在Abeta和Family Tauoophies中的变化相关。体内。因此，拟议的研究应导致对将tau代谢与NFT形成，ABETA沉积物的存在以及AD AD的细胞病理学以及其他NFD的细胞机制以及目前无法从细胞培养或鼠类转基因系统中的研究中无法获得的NFD的细胞机制的基本新见解。