Therapeutic targeting of ATXN2 for sporadic amyotrophic lateral sclerosis (ALS)

项目总结/摘要 肌萎缩侧索硬化症（ALS）是一种致命的、成人发病的神经退行性疾病， 目前没有治愈方法，治疗选择非常有限。患者表现为肌肉无力加重并死亡 在症状发作后3-5年内发生呼吸衰竭。目前，大多数ALS研究都集中在 遗传原因，约占10%的病例（家族性），没有任何治疗 其余90%的患者（零星）。虽然对发病机理还不清楚 或疾病传播，97%的患者共有一个病理学标志：TDP-43定位错误。TDP-43 是一种必需的RNA结合蛋白，在健康患者中在脊髓和皮质运动神经元中表达 原子核。在ALS中，它错误定位于细胞质，在那里它形成不同的磷酸化聚集体， 对神经元有毒。最近，Ataxin-2（ATXN 2）已被鉴定为TDP-43的潜在调节剂 酵母和动物模型中的毒性。为了支持这一发现，5%的ALS患者具有中等长度， 在基因的polyQ区域重复扩增，相比之下，2%的非神经对照。此外，委员会认为， 我们的研究小组和其他人已经证明，无论重复长度如何，ALS患者都表现出 运动神经元中ATXN 2分布的扰动。综上所述，这些表明ATXN 2可能是 反义寡核苷酸（阿索）治疗潜力的候选者，然而，问题仍然是 治疗是否会使所有散发性患者受益或取决于polyQ长度。 该项目提出了一系列旨在检查ATXN 2作为潜在治疗药物的实验 靶向直接来自疾病患者的人体组织，比较有和没有中间体的患者 长度重复扩增。目的是通过检测表达来探索靶点特征和表型 参与疾病的水平和途径。该提案通过降低水平来检查目标参与度 ATXN 2和相关蛋白在途径中的作用，并探索基因组和蛋白质组特征的变化， 发展出一个疾病细胞图谱。最后，它将验证ATXN 2靶向阿索治疗的靶向疗效， 以确定可能从治疗中获益的患者子集。 由于ALS的破坏性，研究重点必须放在治疗潜力上， 直接翻译的方式，以加快治疗目前的病人。该提案将对 然而，可能受益于ATXN 2定向治疗的患者人群，该领域仍然乐观 ATXN 2的去除将使所有患者受益，而不仅仅是中等长度的一小部分患者， 重复。这个可直接翻译的建议，沿着每月在旧金山最大的ALS诊所与病人接触， 迭戈，将提供理想的医生科学家在合作研究和临床环境的培训。

Project Summary / Abstract Amyotrophic lateral sclerosis (ALS) is a fatal, adult onset, neurodegenerative disease for which there is currently no cure and very limited treatment options. Patients present with increasing muscle weakness and die from respiratory failure within 3-5 years post symptom onset. Currently, the majority of ALS research is focused on genetic causes, which account for approximately only 10% of cases (familial), without any treatment developments for the remaining 90% of patients (sporadic). Although nothing is known about the pathogenesis or propagation of disease, 97% of all patients share one pathological hallmark: TDP-43 mislocalization. TDP-43 is an essential RNA binding protein that in healthy patients is expressed in spinal cord and cortical motor neuron nuclei. In ALS it is mislocalized to the cytoplasm where it forms distinct phosphorylated aggregates which may be toxic to the neurons. Recently, Ataxin-2 (ATXN2) has been identified as a potential modulator of TDP-43 toxicity in yeast and animal models. To support this finding, 5% of patients with ALS have intermediate length repeat expansions in the polyQ region of the gene, compared to 2% of non-neurological controls. Furthermore, our group and others have demonstrated that regardless of repeat length, ALS patients demonstrate perturbations in the distribution of ATXN2 in motor neurons. Taken together, these suggest that ATXN2 may be a candidate for antisense oligonucleotide (ASO) therapeutic potential, however, the question remains as to whether therapy would benefit all sporadic patients or be dependent on polyQ length. This project proposes a series of experiments designed to examine ATXN2 as a potential therapeutic target in human tissue directly from patients with disease, comparing patients with and without intermediate length repeat expansions. The aims will explore target characterization and phenotype by examining expression levels and pathways involved in disease. The proposal examines target engagement via knocking down levels of ATXN2 and related proteins in the pathway and exploring the changes in genomic and proteomic signature to develop a disease cellular profile. Lastly, it will verify target efficacy with ATXN2-targeted ASO treatment in order to identify the subset of patients likely to benefit from therapy. Due to the devastating nature of ALS it is imperative that research focus on therapeutic potential in a directly translatable manner in order to expedite treatments for current patients. This proposal will stratify the patient population of those likely to benefit from ATXN2 directed therapy, however, the field remains optimistic that removal of ATXN2 will benefit all patients, not just the small percentage of those with intermediate length repeats. This directly translatable proposal, along with monthly patient contact in the largest ALS clinic in San Diego, will provide ideal physician scientist training in a collaborative research and clinical setting.