Using Drosophila as a model to understand TDP-43 function in ALS

使用果蝇作为模型来了解 TDP-43 在 ALS 中的功能

• 批准号: 8110887
• 负责人: DAVID B MORTON
• 金额: $ 21.75万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8110887
• 关键词: Adult; Affect; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Anatomy; Animals; Biological Models; C-terminal; Cell Death; Cell Nucleus; Characteristics; Cheese; Code; Cytoplasm; Cytoplasmic Inclusion; Data; Defect; Dementia; Development; Disease; Drosophila genus; Drosophila melanogaster; Functional disorder; Future; Gene Proteins; Genes; Genetic; Goals; Human; Investigation; Larva; Lead; Link; Location; Mediating; Modeling; Molecular; Motor; Motor Neuron Disease; Motor Neurons; Mutation; Names; Nature; Nerve Degeneration; Nervous system structure; Neuroanatomy; Neurodegenerative Disorders; Neurons; Parkinson Disease; Pathology; Pathway interactions; Patients; Phenotype; Physiological; Physiology; Predisposition; Process; Property; Protein Isoforms; Proteins; Publishing; RNA-Binding Proteins; Research; Role; Sampling; Speed; System; Testing; Therapeutic; Tissues; Toxic effect; age related; base; drug development; fly; loss of function; motor deficit; mutant; neuron loss; neuropathy target esterase; null mutation; protein TDP-43; protein aggregate; protein function; research study; response; therapy design; therapy development; tool; Adult; Affect; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Anatomy; Animals; Biological Models; C-terminal; Cell Death; Cell Nucleus; Characteristics; Cheese; Code; Cytoplasm; Cytoplasmic Inclusion; Data; Defect; Dementia; Development; Disease; Drosophila genus; Drosophila melanogaster; Functional disorder; Future; Gene Proteins; Genes; Genetic; Goals; Human; Investigation; Larva; Lead; Link; Location; Mediating; Modeling; Molecular; Motor; Motor Neuron Disease; Motor Neurons; Mutation; Names; Nature; Nerve Degeneration; Nervous system structure; Neuroanatomy; Neurodegenerative Disorders; Neurons; Parkinson Disease; Pathology; Pathway interactions; Patients; Phenotype; Physiological; Physiology; Predisposition; Process; Property; Protein Isoforms; Proteins; Publishing; RNA-Binding Proteins; Research; Role; Sampling; Speed; System; Testing; Therapeutic; Tissues; Toxic effect; age related; base; drug development; fly; loss of function; motor deficit; mutant; neuron loss; neuropathy target esterase; null mutation; protein TDP-43; protein aggregate; protein function; research study; response; therapy design; therapy development; tool

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a devastating disease affecting about 2 in 100,000 people in the USA each year. Recent discoveries have the potential to dramatically change our understanding of the causes of ALS and identification of possible targets for treatment. ALS results from the selective loss of motor neurons, which in ALS patients contain cytoplasmic aggregates of proteins. Identification that a major constituent of these aggregates is the RNA-binding protein TDP-43, which is normally localized in the nucleus, has opened up many new directions in ALS research. A large number of mutations in TDP-43 have also been identified in ALS patients providing a causative link between this protein and the disease. TDP-43 aggregates have also been identified in post-mortem samples of patients who have died of other neurodegenerative diseases such as fronto-temporal dementias, Alzheimer's and Parkinson's diseases, suggesting that TDP-43 pathology might be a causative agent in a wide variety of diseases. It is critical to understand how TDP-43 dysfunction leads to disease. Two possible mechanisms have been proposed. The first is that the TDP-43 aggregates are inherently toxic and lead to motor neuron cell death. The second model, which is not mutually exclusive with the first, is that the loss of normally functioning protein in the nucleus is the proximate cause of motor neuron disruption. We are using the fruit fly, Drosophila melanogaster, as a model to understand the function of TDP- 43 in neurons and the consequences of aberrant expression. Null mutations in the Drosophila orthologue of TDP-43, named TBPH, are pupal lethal and show larval motor defects. Over-expression of any of three naturally occurring isoforms of TBPH in all tissues is early larval lethal. When expression is restricted to motor neurons, both larvae and adult flies have motor deficits. The bulk of the TDP-43 mutations in ALS are found in the C-terminal domain and our data shows that the C-terminal domain of TBPH is necessary for maximum toxicity. The primary goals of this application are to determine the cellular and molecular mechanisms underlying these defects. We have identified a genetic interaction between TBPH/TDP-43 and another neurodegeneration gene, named swiss cheese (sws), which suggests that sws is required for the toxic properties of TDP-43. This interaction is particularly intriguing because mutations in the human orthologue of sws, named neuropathy target esterase, lead to motor neuron disease. In addition to testing our hypothesis that the toxic effects of over-expressed TDP-43 result from an interaction between TDP-43 and sws we also propose to examine the anatomical and electrophysiological phenotypes of motor neurons that over-express TDP-43 in wild-type and sws mutant backgrounds. Any therapeutic approaches to treat ALS that rely on targeting TDP-43 dysfunction require an understanding of the molecular mechanisms that underlie the toxic effects of TDP-43. Using the powerful genetic tools available in Drosophila will greatly accelerate this understanding. PUBLIC HEALTH RELEVANCE: The first step in developing therapies for ALS is to identify the genes/proteins that either directly cause ALS or confer susceptibility to develop ALS in response to environmental triggers. Recent discoveries that strongly link TDP-43 to ALS suggest that this is a possible future target. Any therapeutic approaches to treat ALS that rely on targeting TDP-43 dysfunction require an understanding of the molecular mechanisms that underlie the toxic effects of TDP-43. This application focuses on understanding the mechanisms that lead to neurodegeneration by TDP-43 dysfunction using the fruit fly, Drosophila melanogaster as a model, an approach that will greatly speed up the process of designing therapies targeting TDP-43.

描述（由申请人提供）：肌萎缩性侧索硬化症（ALS）是一种毁灭性疾病，每年在美国影响100,000人中约有2人。最近的发现可能会极大地改变我们对ALS原因的理解，并确定可能的治疗靶标。 ALS是由运动神经元选择性丧失的，在ALS患者中含有蛋白质的细胞质聚集体。鉴定这些聚集体的主要成分是通常位于核中的RNA结合蛋白TDP-43，它在ALS研究中打开了许多新方向。在TDP-43中，在ALS患者中也发现了大量的突变，该患者在该蛋白质与该疾病之间提供了致病联系。在死于其他神经退行性疾病的患者的验尸样本中，TDP-43骨料也已被鉴定出来，例如额颞痴呆，阿尔茨海默氏症和帕金森氏病，这表明TDP-43病理学可能是多种疾病的病理学药物。了解TDP-43功能障碍如何导致疾病至关重要。已经提出了两种可能的机制。首先是TDP-43骨料本质上是有毒的，并导致运动神经元细胞死亡。第二个模型与第一个模型不是互斥的，它是核中正常功能蛋白的丧失是运动神经元破坏的直接原因。我们正在使用果蝇果蝇（Drosophila Melanogaster）作为一种模型，以了解TDP-43在神经元中的功能以及异常表达的后果。 TDP-43的果蝇直系同源物中的无效突变，称为TBPH，是pupal致死的，显示出幼虫运动缺陷。在所有组织中，TBPH的三种天然同工型中的任何一个中的任何一个都是幼虫致死的。当表达仅限于运动神经元时，幼虫和成年蝇都有运动缺陷。在C末端结构域中发现ALS中的大部分TDP-43突变，我们的数据表明，TBPH的C末端结构域对于最大毒性是必需的。该应用的主要目标是确定这些缺陷背后的细胞和分子机制。我们已经确定了TBPH/TDP-43与另一个名为Swiss Cheese（SWS）的神经变性基因之间的遗传相互作用，这表明TDP-43的有毒特性需要SWS。这种相互作用尤其引人入胜，因为SWS人类直系同源物（称为神经病靶酯酶）导致运动神经元疾病的突变。除了测试我们的假设外，TDP-43与SWS之间的相互作用导致过表达的TDP-43的毒性作用，我们还建议检查运动神经元的解剖学和电生理表型，这些神经元的解剖学和电生理表型过表达TDP-43的TDP-43在野生型和SWS Mutants中。任何治疗依赖于靶向TDP-43功能障碍的ALS的治疗方法都需要了解TDP-43毒性作用的分子机制。使用果蝇中可用的强大遗传工具将极大地加速这种理解。 公共卫生相关性：为ALS开发疗法的第一步是识别直接引起ALS或会议易受ALS的基因/蛋白质，以响应环境触发因素。最近发现将TDP-43与ALS联系起来的发现表明，这是未来的目标。任何治疗依赖于靶向TDP-43功能障碍的ALS的治疗方法都需要了解TDP-43毒性作用的分子机制。该应用的重点是理解使用果蝇，果蝇Melanogaster作为模型的TDP-43功能障碍导致神经变性的机制，这种方法将大大加快针对TDP-43的疗法的过程。