Creating new Drosophila models to study Tau loss and gain-off functions

创建新的果蝇模型来研究 Tau 损失和增益功能

• 批准号: 9087997
• 负责人: Doris Kretzschmar
• 金额: $ 23.1万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9087997
• 关键词: Address; Affect; Alzheimer' s Disease; Amyloid beta-Protein; Axonal Transport; Binding; Brain; CRISPR/Cas technology; Caliber; Characteristics; Defect; Development; Disease; Dominant-Negative Mutation; Drosophila genus; Ectopic Expression; FTD with parkinsonism; Frontotemporal Dementia; Future; Generations; Genetic; Genetic Transcription; Genetic screening method; Human; Image; In Vitro; Knock-in; Lead; MAPT gene; Measures; Microtubules; Modeling; Modification; Mus; Mutation; Mutation Analysis; Neurodegenerative Disorders; Neurofibrillary Tangles; Pathogenesis; Pathology; Pattern; Phenotype; Phosphorylation; Physiological; Pick Disease of the Brain; Senile Plaques; Supraoptic Vertical Ophthalmoplegia; System; Tauopathies; Time; Transgenic Model; Variant; age related neurodegeneration; base; density; fly; gain of function; in vivo; knock-down; loss of function; mouse model; mutant; novel; overexpression; prevent; progressive neurodegeneration; promoter; public health relevance; research study; tau Proteins; tau function; tau mutation; treatment strategy

 DESCRIPTION (provided by applicant): The microtubule-associated protein Tau is a key component of the intracellular inclusions that are found in Alzheimer's disease (AD) and a variety of other neurodegenerative diseases, together referred to as Tauopathies. However, the mechanisms of pathology in these diseases are still unclear. A long standing debate is whether disease-associated changes in Tau are pathogenic because they induce a loss of its normal function, induce a novel toxic gain-of function, or a combination of both. In addition, the differet disease- associated mutations and modifications of Tau may have different pathogenic mechanisms. Whereas gain-of functions have been investigated in several models, loss of functions have been less well studied and most of the studies addressing such functions have been done in vitro. Furthermore, the majority of gain-of function studies are based on expression system that cause overexpression or ectopic expression, which can cause phenotypes even with normal wild type Tau. To address the hypothesis that the mechanism of pathogenesis are due to combinations of loss-of and gain-of functions and that the degree of their contributions may vary in different Tauopathies, it is proposed to create novel Drosophila models that expressing human Tau instead of fly Tau. Due to their short generation time, the unique genetic means available in this model, and the small size of their brain which allows time lapse imaging of intact brains (to measure microtubule-associated axonal transport), Drosophila provides a uniquely suitable model to analyze these lines in a relatively short time frame. These studies will also take advantage of the recent characterization of flies lacking endogenous fly Tau (dTau), which show age-related neurodegeneration and various microtubules defects. These defined phenotypes will therefore allow an analysis to what degree a mutant Tau has lost its normal function. Creating flies carrying a disease-associated and a wild type form (or a copy of dTau) can be used to study gain-of function effects and the expression by the endogenous fly Tau promoter should prevent overexpression phenotypes. The results obtained in this exploratory proposal can then provide the basis to identify genetic and pharmacological means that interfere with the pathology or its consequences and they can be used to address specific pathogenic mechanisms in the mouse model. Public Heath Relevance: A roadblock in understanding and developing treatment strategies for Tauopathies is that the mechanisms of pathology are still unclear. Identifying loss-of functions versus gain-of functions of disease-associated Tau is critical to develop such treatment strategies. Whereas Tauopathies that are mainly caused by Tau gain-of functions could be ameliorated by reducing Tau, loss-of function phenotypes would be aggravated by such strategies. Similarly, treatment strategies based on stabilizing microtubules would be a promising approach in cases where a mutation causes a loss of the microtubule function but not in cases where they lead to a novel, microtubule independent, gain-of function.

 描述（由适用提供）：微管相关的蛋白质TAU是在阿尔茨海默氏病（AD）和其他各种神经退行性疾病中发现的细胞内夹杂物的关键组成部分，称为tauapathies。但是，这些疾病中病理的机制尚不清楚。长期存在的辩论是，与疾病相关的TAU的变化是致病性的，因为它们会导致其正常功能的丧失，影响新的有毒功能或两者的组合。另外，tau的不同疾病的突变和修饰可能具有不同的致病机制。尽管已经在几种模型中研究了功能获得的收益，但功能损失的研究较少，并且大多数针对此类功能的研究已经在体外完成。此外，大多数功能研究研究基于表达系统，该系统引起过表达或异位表达，即使在正常的野生型TAU中也可能引起表型。为了解决以下假设：发病机理的机理是由于功能丧失和功能损失的组合引起的，并且其贡献程度可能在不同的tauopathies中有所不同，因此建议创建一种新型的果蝇模型，以表达人tau而不是蝇tau。由于它们的短生成时间，该模型中可用的独特遗传手段以及允许完整大脑的延时成像（测量微管相关的轴突运输）的小尺寸，果蝇提供了一个独特的模型，可以在相对较短的时间范围内分析这些线。这些研究还将利用缺乏内源性蝇Tau（DTAU）的果蝇的最新表征，后者显示与年龄相关的神经变性和各种微管缺陷。因此，这些定义的表型将允许突变tau失去其正常功能的程度分析。可以使用携带疾病相关和野生型形式（或DTAU的副本）的苍蝇来研究功能效果，并且内源性蝇Tau启动子的表达应防止过表达表型。然后，在此探索性建议中获得的结果可以提供基础，以识别遗传和药物的方法，即干扰病理或其后果，并且可以用于解决小鼠模型中特定的病原机制。公共荒地相关性：理解和制定对tauopathies的治疗策略的障碍是病理学机制尚不清楚。确定功能丧失与疾病相关的TAU功能的功能对于制定这种治疗策略至关重要。尽管可以通过减少tau来改善主要是由tau功能获得的tauopathies，但这种策略将汇总功能损失表型。同样，在突变会导致微管功能丧失但不会导致新型，微管独立的，独立的功能的情况下，基于稳定微管的治疗策略将是一种有希望的方法。