Investigating the mechanism of UPF1-mediated rescue of TDP-43-based models of ALS and FTD

项目摘要 肌萎缩侧索硬化症（ALS）是一种致命的神经退行性疾病， 失去上下运动神经元，导致瘫痪和死亡。没有可用的疾病修饰 毒品在95%的ALS个体中，受影响的神经元表现出TDP-43的细胞质积累（transactive）， 应答元件DNA/RNA结合蛋白，43 kDa）。TDP-43是一种普遍表达的剪接因子， 通常位于细胞核内。在细胞和动物模型系统中，TDP-43的过表达不会导致 不仅在神经退行性变中，而且在TDP-43细胞溶质错误定位和聚集中，概括了关键 人类的病理变化。编码TDP-43（TARDBP）和几个类似的基因突变 RNA结合蛋白（RBP）（如FUS、HNRNPA 2B 1、MATR 3）引起家族性ALS以及相关的，通常是 共病额颞叶痴呆（FTD）。RBP功能异常如何导致ALS和FTD是一个问题。 正在进行的研究领域;然而，一些证据表明，RNA剪接的全球破坏 稳定是中心主题。 我们和其他人确定RNA解旋酶Up-frameshift 1（UPF 1）的过表达可以改善 在TDP 43和FUS毒性的体内和体外模型中的毒性。本建议旨在阐明 UPF 1介导的神经保护机制，特别是在TDP-43毒性模型中。UPF 1是一种强制性的 无义介导的衰变（NMD）的组成部分，一个重要的RNA监视程序。由于TDP-43的毒性 调节异常与其结合RNA的能力密切相关，该提案侧重于潜在的相互作用 UPF 1和TDP-43底物之间的差异。我假设UPF 1通过以下方式挽救TDP-43毒性：（a）促进 通过NMD清除错配的TDP-43靶标，（B）干扰TDP-43结合RNA的能力，或a 两者的结合。这些调查不仅为我提供了发展基础知识的机会， 实验设计，生物信息学和通信方面的科学技能，但也有望提供新的见解 UPF 1介导的神经保护的治疗潜力。最终，这些机会将 作为一名成功的神经学家和神经科学家， 神经系统疾病，疾病机制和治疗干预。

PROJECT SUMMARY Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of upper and lower motor neurons, leading to paralysis and death. There are no available disease-modifying drugs. In 95% of individuals with ALS, affected neurons exhibit cytoplasmic accumulation of TDP-43 (transactive response element DNA/RNA binding protein, 43 kDa). TDP-43 is a ubiquitously expressed splicing factor that is normally localized to the nucleus. In cellular and animal model systems, overexpression of TDP-43 results not only in neurodegeneration, but also TDP-43 cytosolic mislocalization and aggregation, recapitulating key pathologic changes seen in humans. Mutations in the genes encoding TDP-43 (TARDBP) and several similar RNA-binding proteins (RBPs) (e.g. FUS, HNRNPA2B1, MATR3) cause familial ALS as well as the related, often comorbid disease frontotemporal dementia (FTD). How aberrant RBP function may cause ALS and FTD is an ongoing area of research; nevertheless, several pieces of evidence suggest that global disruption of RNA splicing and stability is a central theme. We and others determined that overexpression of the RNA helicase Up-frameshift 1 (UPF1) ameliorates toxicity in both in vivo and in vitro models of TDP43 and FUS toxicity. This proposal seeks to elucidate the mechanism of UPF1-mediated neuroprotection, particularly in models of TDP-43 toxicity. UPF1 is an obligate component of nonsense-mediated decay (NMD), a vital RNA surveillance program. Since the toxicity of TDP-43 dysregulation is strongly linked to its ability to bind RNA, the proposal focuses on the potential interactions between UPF1 and TDP-43 substrates. I hypothesize that UPF1 rescues TDP-43 toxicity by (a) facilitating the clearance of mispliced TDP-43 targets through NMD, (b) interfering with the ability of TDP-43 to bind RNA, or a combination of both. These investigations will not only provide me with the opportunity to develop fundamental scientific skills in experimental design, bioinformatics, and communication, but also promise to deliver new insight into the therapeutic potential of UPF1-mediated neuroprotection. Ultimately, these opportunities will be instrumental in my path to independence as a successful neurologist and neuroscientist dedicated to the study of neurological conditions, disease mechanisms, and therapeutic interventions.