Characterization of the involvement of the cerebellum in animal models of C9orf72 ALS/FTD

项目总结： 肌萎缩侧索硬化症(ALS)是一种以进行性丢失为特征的神经退行性疾病 大脑和脊髓中的运动神经元。额颞性痴呆(FTD)是由早发性痴呆引起的 由于额叶和颞叶的退化，有认知缺陷以及行为和语言 异常现象。FTD与ALS具有共同的病理生理特征。一种六核苷酸重复序列的扩增 C9orf72内含子是这两种疾病最常见的遗传原因。大多数 到目前为止，C9orf72 ALS/FTD和其他类型的ALS的病理生理学研究主要集中在上部 和较低的运动神经元。最近，一些功能研究发现大脑灰质体积较小。 症状前C9orf72重复扩张型携带者的小脑和C9orf72的解剖学证据 疾病小鼠模型已经显示出小脑变性。此外，病理报告使用 死后或病人的细胞有包涵体、rna焦点、二肽重复蛋白，并减少。 C9ORF72在小脑，特别是浦肯野细胞中的mRNA和蛋白水平，与小脑有关 C9orf72 ALS/FTD发病机制障碍然而，关于动物疾病的研究很少。 专注于小脑的模特。我们对C9orf72基因敲除小鼠的强有力的初步数据揭示了运动 浦肯野细胞活动的缺陷和改变。C9orf72 ALS/FTD患者小脑的功能意义 发病机制尚不清楚，更不用说详细的机制了。这些未知因素阻碍了人们理解 目的：研究C9orf72 ALS/FTD的病理生理机制，并为患者开发有效的治疗方法。的总目标是 本研究旨在利用转基因小鼠研究C9orf72 ALS/FTD的病理生理机制。的具体目标 本应用是为了表征C9orf72 ALS/FTD小鼠模型，以确定小脑在 ALS和FTD的发病机制。我们推测，在症状前阶段，C9orf72突变 小鼠有协调和平衡方面的运动缺陷，小脑的解剖和功能缺陷， 尤其是在Purkinje细胞中，由于C9orf72蛋白功能的丧失和离子通道的改变。 我们计划通过以下具体目标来验证我们的假设：(1)我们将检测C9orf72突变小鼠 行为测试组合，(2)我们将表征神经元的形态、被动膜的性质，以及 浦肯野细胞的内在兴奋性，以及(3)我们将进行急性分离的浦肯野细胞记录和 蛋白质印迹分析以确定参与浦肯野细胞放电改变的离子通道。成功者 AIMS的完成将扩大目前关于小脑参与脑电活动的知识。 C9ORF72介导的ALS/FTD。这应该会大大增加我们对糖尿病的病理生理学的了解。 C9ORF72 ALS/FTD，为其他遗传性ALS的病理生理学研究做出了贡献。此外， 研究结果将支持小脑作为治疗C9orf72 ALS/FTD的潜在治疗靶点。 。

Project Summary: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive loss of motor neurons in the brain and spinal cord. Frontotemporal dementia (FTD) is early-onset dementia caused by degeneration of the frontal and temporal lobes with cognitive deficits and behavioral and language abnormalities. FTD shares pathophysiological features with ALS. A hexanucleotide repeat expansion in an intron of C9orf72 is the most frequently reported genetic cause of both diseases. Most of the pathophysiological studies of C9orf72 ALS/FTD and other types of ALS so far have been focused on upper and lower motor neurons. Recently, several functional studies have detected lower gray matter volume in the cerebellum in pre-symptomatic C9orf72 repeat expansion carriers, and anatomical evidence in C9orf72 disease mouse models have demonstrated cerebellar degeneration. Furthermore, pathology reports using postmortem or patient cells have demonstrated inclusions, RNA foci, dipeptide repeat proteins, and decreased C9orf72 mRNA and protein levels in the cerebellum, especially Purkinje cells, implicating cerebellar dysfunction in the pathogenesis of C9orf72 ALS/FTD. However, there are very few studies in animal disease models focusing on the cerebellum. Our strong preliminary data on C9orf72 knockout mice has revealed motor deficits and altered Purkinje cell activity. The functional significance of the cerebellum in the C9orf72 ALS/FTD pathogenesis is not known, let alone the detailed mechanisms. These unknowns hamper efforts to understand the pathophysiology of C9orf72 ALS/FTD and to develop effective therapies for patients. The overall goal of our research is to use transgenic mice to study the pathophysiology of C9orf72 ALS/FTD. The specific goal of this application is to characterize mouse models of C9orf72 ALS/FTD to determine the role of cerebellum in the pathogenesis of ALS and FTD. We hypothesize that at the presymptomatic stage, the C9orf72 mutant mice have motor deficits in coordination and balance, anatomical and functional deficits in the cerebellum, especially in the Purkinje cells due to the loss of function of C9orf72 protein and changes in the ion channels. We plan to test our hypothesis with the following Specific Aims: (1) we will examine C9orf72 mutant mice in the behavioral test battery, (2) we will characterize neuronal morphology, passive membrane properties, and intrinsic excitabilities of Purkinje cells, and (3) we will perform acutely dissociated Purkinje cell recording and Western blot analysis to determine ion channels involved in the altered firing of Purkinje cells. The successful completion of the Aims will expand the current knowledge concerning the involvement of the cerebellum in C9orf72-mediated ALS/FTD. This should significantly increase our understanding of the pathophysiology of C9orf72 ALS/FTD and contribute to the pathophysiological studies of other genetic ALS. Furthermore, the outcome of the research will support cerebellum as a potential therapeutic target to treat C9orf72 ALS/FTD. .