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

摘要/项目总结： 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， 大脑成分需要更好的理解和评估。上运动神经元（UMN），位于层 5的运动皮层，对自主运动的启动和调制有独特的作用。他们的 进行性变性是在遗传性痉挛性脊髓损伤中观察到的神经病理学的特征性标志。 截瘫（HSP）和肌萎缩侧索硬化（ALS）患者。与其临床重要性形成鲜明对比的是 尽管这些人的生命力和相关性很强，但对他们脆弱性和逐渐丧失的根本原因知之甚少。这 缺乏信息和了解其脆弱性的细胞和遗传基础， 他们的神经变性的共同和独特方面阻碍了我们发展有效和长期的能力， UMN疾病的治疗策略。 为了从细胞和分子的角度对两种不同的UMN变性的机制进行深入的研究， 疾病，如HSP和ALS，我们将利用UCHL1-eGFP小鼠，一个报告细胞系， 其中UMN在基因上标记有荧光。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， 导致ALS，而痉挛蛋白的突变导致HSP。迄今为止，已经产生了许多小鼠模型 来模拟人类的状况我们将hPFN1G118V（由Kiaei博士产生）和SPASTC 448Y小鼠杂交 （由Baas博士产生）与UCHL1-eGFP小鼠进行比较以产生具有这些突变的UMN报告细胞系。以来 我们已经表明，具有TDP-43病理的ALS患者的UMN和TDP-43模型的小鼠UMN共享 在细胞水平上神经变性的相同方面，我们将把注意力集中在神经元和纯化 从大脑的复杂结构中分离出患病的UMN作为"纯"神经元群体， 研究其基因表达谱的动态变化以及与疾病相关的蛋白质， 在他们身上，有着健康的人。作为内部对照，我们将使用与TDP分离的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，而且还因为这一点， 模型更好地代表了ALS的光谱。 完成后，我们的研究结果将开始揭示HSP中UMN脆弱性的共同和独特方面 和肌萎缩侧索硬化症，这也将表明不同的基因和/或蛋白质，负责启动他们的 易损性.最重要的是，我们的研究结果有可能确定感兴趣的药物靶点和途径 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.