Deciphering the role of Ataxin-2 in amyotrophic lateral sclerosis

解读 Ataxin-2 在肌萎缩侧索硬化症中的作用

• 批准号: 10395882
• 负责人: Caitlin Marie Rodriguez
• 金额: $ 3.43万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2022-04-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10395882
• 关键词: Deciphering; role; Ataxin; amyotrophic; lateral

Abstract: Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by progressive loss of voluntary muscle control[1]. The Gitler lab—where I will be conducting this research—discovered that a mutation in the ataxin-2 gene (ATXN2) is a relatively common genetic risk factor for ALS[2]. The mutation is an intermediate-length expansion of a CAG repeat in the ATXN2 coding region, leading to longer polyglutamine tracts in the Ataxin-2 protein. Reduction of the wild-type Atxn2 transcript extended survival and reduced pathology in a mouse model of ALS, as did crossing this mouse with the Ataxin-2 knockout mouse[3]. Despite these promising results, little is known about how wild-type Ataxin-2 contributes to ALS. Defects in RNA metabolism has emerged as a central mechanism in ALS[4-6]. Ataxin-2 is a regulator of mRNA translation, however transcripts under its control have only been identified on a case-by-case basis[7-12]. First, I am interested in exploring how knockout of Ataxin-2 elicits deficits in translation, and if this affords motor neurons protection in the transgenic TDP-43 (TDP-43tg/tg) ALS mouse model. I will use the expertise I gained during graduate school to perform genome-wide and biochemical translation assays, but combine this with a new set of techniques for investigating mRNA dynamics in complex tissue. I will perform TRAP-seq, a technique for gauging the level of translation on individual transcripts by purifying mRNA bound to translating ribosomes[13]. This will allow me to determine transcripts with differential translation in TDP-43tg/tg mouse motor neurons, and how that is affected by the Ataxin-2 knockout. Ataxin-2 is an integral component of specialized messenger ribonucleoprotein (mRNP) granules, and interacts with TDP-43 through RNA association[2, 8, 14]. mRNP granules are involved in the transport of mRNA to various parts of the cell for proper posttranscriptional processing[15, 16]. Deficits in axonal mRNA localization have been detected in both cultured peripheral neurons and mouse embryonic stem cell-derived motor neurons from multiple transgenic ALS mouse models, but never directly from tissue as the technology was not previously available[17, 18]. I will employ a novel technique called APEX-seq to determine the composition of mRNA transcripts spatially constricted to peripheral motor axons in WT and TDP-43tg/tg mice, and how this changes when crossed to the Ataxin-2 knockout[19, 20]. As described in my second aim, I will perform a genome-wide siRNA screen in human cells to discover regulators of Ataxin-2 that will illuminate pathways that work upstream to control its expression. The Gitler lab is proficient in large-scale approaches to identifying disease modifiers[21-23]. The goal of this aim is to harness our results to devise novel therapeutic strategies and to expand my training to include genome-wide screening. This project allows me the opportunity to expand my expertise in the topic of RNA metabolism in neurological disease, the topic I plan to make my career in researching, and to decipher the most promising targets for therapeutic development and future study.

抽象的： 肌萎缩性侧索硬化症（ALS）是一种毁灭性的神经退行性疾病，其特征是程序。 丧失自愿肌肉控制[1]。 Ataxin-2基因中的突变（ATXN2）是ALS的相对常见遗传风险因素[2]。 在编码更长的聚谷氨酰胺的ATXN2中，CAG重复的中间长度扩展 野生型ATXN2转录物的降低，降低生存率，并降低 ALS的小鼠模型中的病理，尽管尽管如此，但与Ataxin-2基因敲除小鼠越过了[3] 这些有希望的结果，关于如何野生型Ataxin-2有助于ALS的缺陷 代谢已成为ALS中的一种中心机制[4-6]。 但是，在其控制下的成绩单是通过具体情况确定的[7-12]，我是 有兴趣探索ataxin-2的敲除如何在翻译中引起缺陷，以及ifords运动神经元 转基因TDP-43（TDP-43TG/TG）ALS鼠标模型中的保护。 遍及表演的研究生院和生化翻译测定法，但结合了一套 用于研究复杂组织中mRNA动力学的技术。 通过净化与翻译核糖体的mRNA净化单个转录本上的翻译水平[13] 这将使我能够在TDP-43TG/TG小鼠运动神经元中设计具有差分翻译的成绩单，并且 Ataxin-2敲除如何隶属于Ataxin-2。 核糖蛋白（MRNP）颗粒，并通过RNA关联与TDP-43相互作用[2，8，14] 颗粒参与mRNA到各种细胞福尔的转运后正确的转递后转运 处理[15，16]。 来自多个转基因ALS Mousels的神经元和小鼠胚胎干细胞衍生的运动神经元， 但是，由于该技术以前无法使用，因此从不直接来自组织[17，18]。 称为Apex-Seq的技术，以确定mRNA转录的组成在空间上限制为 WT和TDP-43TG/TG小鼠中的外围运动轴突，以及越过ataxin-2时如何变化 敲除[19，20]。 发现Ataxin-2的调节剂将阐明在上游控制其表达的途径 吉特勒实验室是识别疾病修饰符的大规模方法[21-23]。 为了利用我们的结果制定新颖的治疗策略并扩大我的培训以包括全基因组 筛选。 神经疾病，我计划研究职业的主题，并破译最有前途的话题 治疗发展和未来研究的目标。