Exploring DYT1 pathogenesis: torsinA and the nuclear envelope

描述（由申请人提供）：我的长期职业目标是了解神经疾病背后的生物学异常，并应用这些知识来改善患有这些疾病的患者的生活质量。在训练期间，我对遗传性肌张力障碍产生了浓厚的兴趣。肌张力障碍是一种神经系统综合症，其特征是长时间的扭曲不自主运动，通常是刻板印象。肌张力障碍的几种遗传形式已经被描述过，其中DYT1最为常见。我最初是在博士后培训期间对DYT1肌张力障碍产生了特别的兴趣和研究。我现在需要掌握必要的技能来评估torsinA的正常功能，DYT1中突变的蛋白，以及在培养细胞和动物模型中疾病状态下的功能障碍。为了实现这一目标，我已经与几位科学家开展了合作，并将在爱荷华大学神经病学部门开展拟议的工作。TorsinA是四种密切相关的哺乳动物torsin蛋白之一。最近DYT1研究的一项突破表明，突变体torsinA通常存在于内质网（ER）中，而在核膜（NE）中积累。从这个位置，已经发现torsinA调节细胞质蛋白聚集成聚合体。torsinA在核膜中的作用是什么，当突变时如何导致神经元功能障碍，如何调节聚集体，以及什么因素导致疾病外显率降低，这些问题仍然没有答案。根据最近的报告和我自己的初步结果，我将直接回答这些问题。在目标1中，我将确定torsinA如何调节NE蛋白的动态行为并影响这种亚细胞结构的蛋白质组成。在目标2中，我将使用一种新的动态显微镜系统和基本的生物学技术来定义torsinA如何影响聚合体的形成。在Aim 3中，我将使用RNA干扰同时在培养细胞和体内沉默不同的torsin基因家族成员，以确定它们作为torsin诱导功能障碍的调节剂的潜在作用。该项目将提供有关torsinA功能的重要信息，并可能揭示改变DYT1肌张力障碍外显率降低的因素，为预防所有突变携带者的疾病发展提供治疗策略。这个提案是我计划在我的职业生涯中进行的与临床相关的基础神经生物学研究的例证。

DESCRIPTION (provided by applicant): My long-term career goal is to understand the biological abnormalities underlying neurological disorders and apply that knowledge to improve the quality of life of patients suffering from them. During my training period, I developed a strong interest on the inherited dystonias. Dystonia is a neurological syndrome characterized by prolonged twisting involuntary movements that are frequently stereotyped. Several genetic forms of dystonia have been described, being DYT1 the most common. I initially became specially interested and studied DYT1 dystonia during my postdoctoral training. I now need to acquire skills necessary to assess the normal function of torsinA, the protein mutated in DYT1, and its dysfunction in the disease state in cultured cells and animal models. To accomplish this goal, I have developed collaborations with several scientists and will pursue the proposed work within the Department of Neurology at The University of Iowa. TorsinA is one of four closely related mammalian torsin proteins. A recent breakthrough in DYT1 research demonstrated that, while normally residing in the endoplasmic reticulum (ER), mutant torsinA accumulates in the nuclear envelope (NE). From this location, torsinA has been found to modulate aggregation of cytoplasmic proteins into aggresomes. What is the role of torsinA in the nuclear envelope, how leads to neuronal dysfunction when mutated, how modulates aggresome and what factors condition the reduced penetrance of the disease remain unanswered questions. Building on recent reports and my own preliminary results, I will directly address those questions. In Aim 1, I will determine how torsinA modulates the dynamic behavior of NE proteins and influences the protein composition of this subcellular structure. In Aim 2, I will use a novel dynamic microscopy system and basic biological techniques to define how torsinA influences aggresome formation. In Aim 3, I will use RNA interference to simultaneously silence the different torsin gene family members in cultured cells and in vivo to determine their potential role as modulators of torsinA-induced dysfunction. This project will yield important information concerning the function of torsinA, and may uncover the factors that modify the reduced penetrance of DYT1 dystonia, providing therapeutic strategies to prevent the development of the disease in all mutation carriers. This proposal exemplifies the type of clinically related fundamental neurobiological research I plan to pursue during my career.