A Drosophila model to investigate prion-like transmission of Huntington's disease

研究亨廷顿病的朊病毒样传播的果蝇模型

基本信息

批准号：
8305582
负责人：
Margaret Panning Pearce
金额：
$ 5.39万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-06 至 2013-07-26
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8305582
关键词：
Adopted Alzheimer&apos s Disease Amyloid Basal Ganglia Behavior Biochemistry Biophysics Brain Brain region Cell Surface Proteins Cell surface Cells Cellular biology Cherry - dietary Coculture Techniques Complex Corpus striatum structure Cultured Cells Cytoplasm Data Deposition Deterioration Disease Disease Progression Drosophila genus Extracellular Space Genes Genetic Glutamine Green Fluorescent Proteins Hippocampus (Brain)Huntington Disease Individual Inherited Investigation Knowledge Lateral Life Measures Mediating Mentors Mitotic Modeling Motor Mutation Nerve Degeneration Neurodegenerative Disorders Neurologic Neurons Parkinson Disease Pathology Peptide Hydrolases Phenotype Process Property Proteins RNA Interference Reporting Role Staging Symptoms Synapses Testing Tissues Transgenic Organisms Trypsin brain tissue cell type cognitive function cytotoxic cytotoxicity extracellular fly gain of function human Huntingtin protein in vivo insight loss of function monomer motor impairment mutant neuron loss neuronal cell body neuronal circuitry polyglutamine prion-like protein aggregation tool transmission process uptake

项目摘要

Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by a progressive deterioration in motor and cognitive function, and its primary genetic cause is the expansion of a polyglutamine (polyQ) tract near the N-terminus of the ubiquitously-expressed, cytosolic protein huntingtin (Htt). Mutant Htt adopts a cytotoxic gain-of-function that causes it to polymerize into insoluble, amyloid-like fibrillar aggregates that are initially deposited in medium spiny neurons in the striatum of the basal ganglia but in later stages of disease, spread to neurons in neighboring brain regions (e.g. the hippocampus and cortex). While it is clear that deposition of Htt aggregates correlates with neuronal cell death, the exact mechanism by which they contribute to cytotoxicity or spread through brain tissue is currently unknown. Recent studies suggest that extracellular Htt aggregates have prion-like properties; i.e. they can trigger the templated conformational change of soluble monomers and transmit the misfolded state to naove cells. Further, emerging evidence suggests that aggregates formed by proteins associated with other neurodegenerative disorders (e.g. Alzheimer's and Parkinson's diseases) also adopt prion-like behavior, suggesting that progression of these diseases may occur by a common mechanism. The overall aim of this proposal is to establish a Drosophila model to demonstrate whether prion-like transmission of HD pathology can be recapitulated in vivo and to explore the mechanism(s) involved in this process. Specific Aim 1 investigates whether the aggregation phenotype can be transmitted from neurons expressing aggregation-prone Htt containing a pathogenic polyQ tract to synaptically-connected neurons expressing soluble Htt with a non-pathogenic polyQ tract. Specific Aim 2 explores an alternative but not necessarily mutually exclusive possibility, that Htt-induced aggregation is transmitted between adjacent, non-synaptically-connected cells. These studies will exploit detailed knowledge of Drosophila olfactory neuronal circuitry and various genetic tools to express pathogenic and non-pathogenic Htt proteins in distinct cell types within an individual fly. The focus of Specific Aim 3 is to identify determinants for the lateral transmission of Htt-induced aggregation in a Drosophila model to gain insight into the mechanism(s) involved in this process. These studies will employ a loss-of-function screen in which genes encoding cell surface and secreted proteins are depleted by RNA interference, and effects will be measured by examining how the spread of Htt-induced aggregation to synaptically-connected and/or neighboring cells is altered. Together, these approaches will expand our current understanding of how Htt aggregates propagate between cells with prion-like properties in an in vivo setting, and will lend insight into the mechanism by which the pathology of HD and other neurodegenerative disorders progress along stereotypical paths through the brains of afflicted individuals.

亨廷顿氏病（HD）是一种遗传性神经退行性疾病，其特征是运动和认知功能的进行性恶化，其主要遗传原因是在无处不在表达的，巨谷氨酰胺（Polyq）的扩张附近的多谷氨酰胺（Polyq）裂纹的扩展。 Mutant HTT采用了一种细胞毒性功能，使其成为不溶性的，淀粉样蛋白样的纤维状骨料，最初沉积在中等棘神经神经节的中等棘神经元中，但在疾病的后期阶段，但在附近的大脑区域中扩散到邻近的大脑区域（E.GippocoCappus）。虽然很明显，HTT聚集物的沉积与神经元细胞死亡相关，但目前尚不清楚它们有助于细胞毒性或通过脑组织扩散的确切机制。最近的研究表明，细胞外HTT骨料具有类似prion的特性。即它们可以触发可溶性单体的模板构象变化，并将错误折叠状态传输到Naove细胞。此外，新兴的证据表明，由与其他神经退行性疾病相关的蛋白质形成的骨料（例如，阿尔茨海默氏病和帕金森氏病）也采用了类似prion的行为，表明这些疾病的进展可能是通过一种共同机制发生的。该提案的总体目的是建立果蝇模型，以证明在体内是否可以概括HD病理学的prion样传播，并探索此过程中涉及的机制。具体目标1研究是否可以从表达聚集的HTT的神经元中传播聚集表型，该神经元含有含有致病性的PolyQ片段，以表达具有非致病性Polyq Tract的可溶性HTT的突触连接的神经元。特定的目标2探讨了一种替代方案，但不一定是互斥的可能性，即HTT诱导的聚集是在相邻的非突触连接细胞之间传播的。这些研究将利用果蝇嗅觉神经元电路和各种遗传工具的详细知识，以在单个蝇中不同细胞类型中表达致病性和非致病性HTT蛋白。特定目的3的重点是确定果蝇模型中HTT诱导的聚集的横向传输的决定因素，以深入了解此过程中涉及的机制。这些研究将采用功能丧失的屏幕，其中编码细胞表面和分泌蛋白的基因被RNA干扰耗尽，并通过检查如何改变HTT诱导的聚集到突触连接和/或相邻细胞的传播来测量效果。总之，这些方法将扩展我们对HTT聚集在体内环境中具有类似prion的特性的细胞之间如何在细胞之间传播的最新理解，并将深入了解HD的病理和其他神经退行性疾病的病理，沿着刻板印象的路径通过受访者的大脑沿刻板印象沿刻板印象沿线发展。