A Drosophila model of motor neuron disease using mutations in P150 / Dynactin.

肌萎缩侧索硬化症(ALS)是一种致命的运动神经元退行性疾病，没有已知的 原因或有效的治疗。我们对肌萎缩侧索硬化症的发病机制缺乏了解，部分原因是缺乏简单的 运动神经元变性的动物模型。候选人托马斯·劳埃德医学博士提议 利用强大的遗传有机体表征和利用运动神经元病的新模型 黑腹果蝇。新出现的数据表明，轴突运输或其他囊泡运输方面的缺陷 这些事件可能是这种疾病的主要原因。探讨小泡转运在运动神经元中的作用 疾病，我们在果蝇中引入了dynactin P150亚单位的突变，这种突变存在于 罕见的家族性肌萎缩侧索硬化。表达突变型P150的果蝇有几种表型让人联想到ALS 包括突变蛋白聚集体、轴突运输缺陷和成人起病的进行性瘫痪 和早逝。这项提议的目标是进一步描述这种简单的运动遗传模型 神经疾病，然后用它来筛选运动神经元变性的遗传抑制因子。目标1 将在体外研究疾病相关的P150突变对果蝇囊泡运输的影响 并在体内测试这些突变扰乱特定囊泡运输过程的假设。目标2将 检验疾病相关P150突变导致运动神经元和神经肌肉连接的假设 与肌萎缩侧索硬化症患者相似。目标3将首先描述已确定的 突变体P150对这些运动神经元表型的抑制作用。然后我们将对果蝇的基因组进行筛选 寻找更多突变型P150的遗传修饰物，希望发现与疾病相关的新基因 发病机制，一种在小鼠模型中不可行的强大方法。已确定的遗传相互作用因素是潜在的 药物靶点，所以这项提议的未来方向是验证小鼠模型中已识别的相互作用基因 肌萎缩侧索硬化症。拟议的研究将在汽车专家亚历克斯·科洛德金的实验室进行。 在罗伯特中心主任杰夫·罗斯坦的指导下，果蝇和小鼠的神经元连接 帕卡德肌萎缩侧索硬化研究中心。约翰霍普金斯大学的神经科学和神经病学系提供 为学术神经学家的发展提供了一个特殊的环境。培训和指导 这笔赠款将为劳埃德博士提供成为一名成功的 独立内科医生-科学家，他将致力于寻找治疗肌萎缩侧索硬化的新方法。 相关性：ALS治疗方法的发展因缺乏简单的动物模型而受阻 这种病。这项建议将描述ALS的一种新的果蝇模型，以帮助理解 导致肌萎缩侧索硬化症的原因，并帮助寻找这种毁灭性疾病的新药靶点。

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease of motor neurons without a known cause or effective treatment. Our poor understanding of ALS pathogenesis is partly due to a lack of simple animal models of motor neuron degeneration. The candidate, Thomas Lloyd M.D., Ph.D. proposes to characterize and utilize a novel model of motor neuron disease using the powerful genetic organism Drosophila melanogaster. Emerging data suggest that defects in axonal transport or other vesicle trafficking events may be a primary cause of this disease. To investigate the role of vesicle transport in motor neuron disease, we have introduced a mutation in the P150 subunit of dynactin into Drosophila that is present in a rare familial form of ALS. Flies expressing mutant P150 have several phenotypes reminiscent of ALS including aggregates of mutant protein, defects in axonal transport, and adult-onset, progressive paralysis and early death. The goal of this proposal is to further characterize this simple genetic model of motor neuron disease, and then to use it to screen for genetic suppressors of motor neuron degeneration. Aim 1 will investigate the effects of disease-associated P150 mutations on vesicle transport in Drosophila in vitro and in vivo to test the hypothesis that these mutations disrupt specific vesicle transport processes. Aim 2 will test the hypothesis that disease-associated P150 mutations cause motor neuron and neuromuscular junction pathology resembling that seen in ALS patients. Aim 3 will first characterize the effect of an identified suppressor of mutant P150 on these motor neuron phenotypes. We will then screen the Drosophila genome for additional genetic modifiers of mutant P150 in hopes of identifying novel genes critical to disease pathogenesis, a powerful approach not feasible in mouse models. Identified genetic interactors are potential drug targets, so a future direction of this proposal is to validate identified interacting genes in mouse models of ALS. The studies proposed will be carried out in the laboratory of Alex Kolodkin, an expert in motor neuron connectivity in Drosophila and mice, with mentorship from Jeff Rothstein, director of the Robert Packard Center for ALS Research. The neuroscience and neurology departments at Johns Hopkins provide an exceptional environment for the development of academic neurologists. The training and mentorship provided by this grant will give Dr. Lloyd the expertise and tools needed to become a successful, independent physician-scientist who will devote his career to identifying new treatments for ALS. RELEVANCE: The development of treatments for ALS is hindered by the lack of simple animal models of this disease. This proposal will characterize a new fruitfly model of ALS to help understand the genetic causes of ALS and to help find new drugs targets for this devastating disease.