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（由申请人提供）：微管相关蛋白 Tau 是阿尔茨海默病 (AD) 和多种其他神经退行性疾病（统称为 Tau 病）中发现的细胞内包涵体的关键成分。然而，这些疾病的病理机制仍不清楚。一个长期存在的争论是，与疾病相关的 Tau 蛋白变化是否具有致病性，因为它们会导致其正常功能丧失、导致新的毒性功能获得，或两者兼而有之。此外，不同疾病相关的Tau突变和修饰可能具有不同的致病机制。虽然功能获得已在多种模型中进行了研究，但功能丧失的研究较少，并且大多数针对此类功能的研究都是在体外进行的。此外，大多数功能获得研究都是基于导致过度表达或异位表达的表达系统，即使正常野生型 Tau 也可能导致表型。为了解决以下假设：发病机制是由于功能丧失和功能获得的组合造成的，并且它们的贡献程度在不同的 Tau 病中可能有所不同，建议创建表达人类 Tau 而不是果蝇 Tau 的新型果蝇模型。由于其生成时间短、该模型中可用的独特遗传手段以及其大脑尺寸较小，允许对完整大脑进行延时成像（以测量微管相关的轴突运输），果蝇提供了一个独特的合适模型来在相对较短的时间内分析这些细胞系。这些研究还将利用最近对缺乏内源性果蝇 Tau (dTau) 的果蝇的表征，这些果蝇显示出与年龄相关的神经退行性变和各种微管缺陷。因此，这些定义的表型将允许分析突变 Tau 失去其正常功能的程度。创建携带疾病相关和野生型形式（或 dTau 副本）的果蝇可用于研究功能获得效应，并且内源果蝇 Tau 启动子的表达应防止过度表达表型。这一探索性提议中获得的结果可以为识别干扰病理学或其后果的遗传和药理学手段提供基础，并且它们可用于解决小鼠模型中的特定致病机制。公共卫生相关性：理解和制定 Tau蛋白病治疗策略的障碍是病理机制仍不清楚。确定与疾病相关的 Tau 蛋白的功能丧失与功能获得对于制定此类治疗策略至关重要。虽然主要由 Tau 功能获得引起的 Tau 病可以通过减少 Tau 来改善，但这种策略会加剧功能丧失表型。同样，在突变导致微管功能丧失的情况下，基于稳定微管的治疗策略将是一种有前途的方法，但在突变导致新的、独立于微管的功能获得的情况下则不然。