Profiles of Common and Unique aspects of Upper Motor Neuron degeneration in HSP and ALS

摘要/项目摘要： 运动从大脑开始。特别是对于影响随意运动的运动神经元疾病， 大脑的组成部分需要更好的理解和评估。上运动神经元 (UMN)，位于层 运动皮层的 5 个区域对于随意运动的启动和调节具有独特的作用。他们的 进行性变性是遗传性痉挛中观察到的神经病理学特征 截瘫（HSP）和肌萎缩侧索硬化症（ALS）患者。与其临床重要性形成鲜明对比 和相关性，但人们对其脆弱性和逐渐丧失的根本原因知之甚少。这个 缺乏对其脆弱性的细胞和遗传基础的信息和了解，以及 他们的神经退行性变的共同和独特方面阻碍了我们开发有效和长期的能力 UMN 疾病的治疗策略。 努力从两个不同的方面深入了解 UMN 变性的细胞和分子基础 疾病，如 HSP 和 ALS，我们将利用 UCHL1-eGFP 小鼠，这是一种报告系 UMN 是用荧光进行基因标记的。在本提案中，我们将重点关注 Profilin 和 Spastin，因为像 Spastin 一样，Profilin 是一种肌动蛋白/微管蛋白结合蛋白，并且 Profilin 中的突变 导致 ALS，而 spastin 突变则导致 HSP。迄今为止，已经生成了许多小鼠模型 模仿人类的状况。我们将 hPFN1G118V（由 Kiaei 博士生成）和 SPASTC448Y 小鼠杂交 （由 Baas 博士生成）与 UCHL1-eGFP 小鼠一起生成具有这些突变的 UMN 报告系。自从 我们已经表明，具有 TDP-43 病理学的 ALS 患者的 UMN 与 TDP-43 模型的小鼠 UMN 相同 与细胞水平上的神经退行性疾病相同的方面，我们将把注意力集中在神经元上并纯化 来自大脑复杂结构的患病 UMN 作为处于不同阶段的“纯”神经元群体 疾病来研究其基因表达谱以及相关蛋白质的动态变化 就健康的 UMN 而言，存在于其中。作为内部控制，我们将使用与 TDP-隔离的 UMN 43 小鼠模型不仅因为 TDP-43 病理学在 ALS 和 HSP 中广泛观察到，还因为这 模型更好地代表了 ALS 的谱系。 完成后，我们的结果将开始揭示 HSP 中 UMN 漏洞的常见和独特方面 和 ALS，它还将表明负责启动其的一组不同的基因和/或蛋白质 脆弱性。最重要的是，我们的结果有可能确定可药物靶标和感兴趣的途径 用于未来的治疗干预。

ABSTRACT/ PROJECT SUMMARY: The movement starts in the brain. Especially for motor neuron diseases, which impact voluntary movement, the brain component requires better understanding and assessment. Upper motor neurons (UMNs), located in layer 5 of the motor cortex, have a unique role for the initiation and modulation of voluntary movement. Their progressive degeneration is the characteristic hallmark of neuropathology observed in hereditary spastic paraplegia (HSP) and amyotrophic lateral sclerosis (ALS) patients. In striking contrast to their clinical importance and relevance, very little is known about the underlying causes of their vulnerability and progressive loss. This lack of information and understanding of the cellular and genetic basis of their vulnerability, as well as the common and unique aspects of their neurodegeneration hinders our ability to develop effective and long-term treatment strategies for diseases of the UMN. In an effort to bring a mechanistic insight into the cellular and molecular basis of UMN degeneration in two distinct diseases, such as HSP and ALS, we are going to take advantage of the UCHL1-eGFP mice, a reporter line in which the UMNs are genetically labeled with fluorescence. In this proposal, we will focus our attention to the Profilin and Spastin, because like Spastin, Profilin is an actin/tubulin-binding protein, and mutations in profilin results in ALS, whereas mutations in spastin results in HSP. To date numerous mouse models are generated to mimic the human condition. We crossed the hPFN1G118V (generated by Dr. Kiaei) and SPASTC448Y mice (generated by Dr. Baas) with UCHL1-eGFP mice to generate the UMN reporter lines with these mutations. Since we have shown that the UMNs of ALS patients with TDP-43 pathology and mouse UMNs of TDP-43 model share the same aspects of neurodegeneration at a cellular level, we will focus our attention to the neurons and purify diseased UMNs from the complex structure of the brain as a “pure” neuron population at different stages of the disease to investigate the dynamic changes in their gene expression profile as well as the proteins that are present in them, with respect to the healthy UMNs. As an internal control, we will use UMNs isolated from TDP- 43 mouse model not only because TDP-43 pathology is widely observed in ALS and HSP, but also because this model better represents the spectrum of ALS. Upon completion, our results will begin to reveal the common and unique aspects of UMN vulnerability in HSP and ALS, it will also suggest the distinct set of genes and/or proteins that are responsible for the initiation of their vulnerability. Most importantly our results have the potential to identify druggable targets and pathways of interest for future therapeutic interventions.