Characterization of ATXN2 as a target for ALS in SCA2 motor neurons

项目摘要/摘要 根据世卫组织的估计，神经退行性疾病代表着不断增加的社会和经济负担 这表明，到2040年，它们将取代癌症，成为第二大死亡原因。在神经退行性变中 在疾病研究中，已经发现了大量的途径，但它们与 人类各自的疾病很难证明，靶向通路仍然很困难。这个 拟议的工作将表征ATXN2及其调控的通路，作为治疗的靶点 肌萎缩侧索硬化症(ALS)，每25,000人中就有1人患有这种疾病。ATXN2基因是 脊髓小脑性共济失调2型(SCA2)的突变，这是一种影响小脑的遗传性神经退行性疾病 小脑和脑干中的浦肯野细胞(PC)和其他神经元。我们和其他人的研究表明 研究表明，ATXN2中CAG重复序列的长时间正常扩张显著增加了ALS的风险。更多 最近，一些ALS小鼠模型和培养的ALS神经元模型的存活(或寿命)被证明 与ATXN2突变或总体表达水平相关的修饰。ATXN2在mRNA中的功能 代谢基于其与包括A2BP1/RBFOX1在内的多个RNA结合蛋白(RBPs)的相互作用， DDX6、PABP1和ALS蛋白TDP-43、FUS。我们的最新数据表明，突变的ATXN2 与应激颗粒(SG)RNA相互作用蛋白Staufen1相互作用，这种相互作用具有特异性 对SGS的下游影响。由于ALS运动神经元也以RNA颗粒为特征，ATXN2. 运动神经元中Staufen阳性RNA颗粒的调节功能可能与ALS有关。的目标是 这笔拨款是为了利用人类多能干细胞来源的细胞来研究ATXN2作为ALS的治疗靶点。 ALS和SCA2患者的运动神经元。提出了三个具体目标：1)我们将执行基因 编辑一组多能干细胞系(“CRISPR编辑”)，创建多对细胞 除了ATXN2基因的编辑改变外，在基因上是相同的(同基因)。2)然后我们将广泛 描述这些细胞与ALS细胞在分化为运动神经元时的表型。3)我们 将决定如何使用我们现有的ATXN2反义寡核苷酸DNA来降低ATXN2的表达 药物改变患者AIM 1产生的运动神经元的表型，包括RNA的动力学 颗粒中存在ATXN2突变。拟议的工作将澄清SGS在 神经变性，将有助于确定ALS和其他疾病的治疗新途径 包括SCA2在内的退行性共济失调。

Project Summary/Abstract Neurodegenerative diseases represent an ever-increasing societal and economic burden with WHO estimates indicating that they will replace cancer as the 2nd leading cause of death by 2040. In neurodegenerative disease research, a wealth of pathways has been uncovered, but their direct and primary relevance to the respective human disease has been difficult to prove and targeting of pathways has remained difficult. The proposed work will characterize ATXN2 and pathways regulated by ATXN2 as therapeutic targets for amyotrophic lateral sclerosis (ALS), a disease burdening 1 out of 25,000 individuals. The ATXN2 gene is mutated in spinocerebellar ataxia type 2 (SCA2), a hereditary neurodegenerative disease affecting cerebellar Purkinje cells (PCs) and other neurons in the cerebellum and brainstem. Studies by us and others have demonstratedthat long normal CAG-repeat expansions in ATXN2 significantly increase the risk of ALS. More recently, survival (or lifespan) of some ALS mouse models and cultured ALS neuronal models were shown to be modified in association with ATXN2 mutation or overall level of expression. ATXN2 functions in mRNA metabolism based on its interactions with multiple RNA binding proteins (RBPs) including A2BP1/RBFOX1, DDX6, PABP1, and the ALS proteins TDP-43, FUS. Our most recent data demonstrate that mutant ATXN2 interacts with the stress granule (SG) RNA interacting protein Staufen1, and that this interaction has specific downstream effects on SGs. Since ALS motor neurons are also characterized by RNA granules, ATXN2 functions regulating staufen positive RNA granules in motor neurons may be relevant to ALS. The objective of this grant is to investigate ATXN2 as a therapeutic target for ALS using human pluripotent stem-cell-derived motor neurons from ALS and SCA2 patients. Three specific aims are proposed: 1) We will perform gene editing a panel of pluripotent stem cell lines (“CRISPR editing”) creating multiple pairs of cells that are genetically identical (“isogenic”) except for the edited change at of the ATXN2 gene. 2) We will then extensively characterize the phenotype of these cells vs ALS cells when differentiated to motor neurons neurons. 3) We will determine how lowering the expression of ATXN2 using our existing ATXN2 antisense oligonucleotide DNA drug alters the phenotypes of patient motor neurons generated in aim 1, including the dynamics of RNA granules in the presence of ATXN2 mutation. The proposed work will clarify the role for SGs in neurodegeneration and will aid in the identification of new avenues toward treatments of ALS and other degenerative ataxias including SCA2.