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

摘要/项目摘要： 这种运动始于大脑。特别是对于影响自主运动的运动神经元疾病， 大脑部分需要更好的理解和评估。上运动神经元(UMN)，位于层中 5运动皮质，对自主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的神经病理学特征 截瘫(HSP)和肌萎缩侧索硬化症(ALS)患者。与它们的临床重要性形成鲜明对比 尽管如此，人们对其脆弱性和逐渐丧失的根本原因知之甚少。这 对其脆弱性的细胞和遗传基础缺乏信息和了解，以及 他们神经退化的共同和独特方面阻碍了我们发展有效和长期的 UMN疾病的治疗策略。 为了从机制上洞察UMN退变的细胞和分子基础，在两个不同的 疾病，如HSP和ALS，我们将利用UCHL1-EGFP小鼠，一条报道行 UMN被基因标记为荧光。在这份提案中，我们将把注意力集中在 Profilin和Spastin，因为Profilin和Spastin一样，是一种肌动蛋白/微管结合蛋白，Profilin中的突变 导致肌萎缩侧索硬化症，而spastin突变导致HSP。到目前为止，已经产生了大量的鼠标模型 来模仿人类的状况。我们将hPFN1G118V(由Kiaei博士培育)和SPASTC448Y小鼠进行了杂交 (由Baas博士创建)与UCHL1-EGFP小鼠一起生成具有这些突变的UMN报告系。自.以来 TDP-43病理的ALS患者的UMNS与TDP-43模型的小鼠UMNS是相同的 在细胞水平上，神经退化的相同方面，我们将把注意力集中在神经元上，并净化 疾病的UMN来自复杂的结构的大脑作为一个“纯”神经元群体在不同的阶段 以研究它们的基因表达谱的动态变化以及 关于健康的UMN，存在于它们之中。作为内部控制，我们将使用与TDP分离的UMN- 43小鼠模型不仅是因为TDP-43病理在ALS和HSP中被广泛观察到，而且还因为 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漏洞的共同和独特方面 和ALS，它还将暗示一组独特的基因和/或蛋白质，这些基因和/或蛋白质负责启动其 脆弱性。最重要的是，我们的结果有可能确定可用药的目标和感兴趣的途径 为未来的治疗干预做准备。

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.