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

项目总结 肌萎缩侧索硬化症(ALS)是一种以进行性神经退行性疾病为特征的致死性神经退行性疾病 上下运动神经元的丧失，导致瘫痪和死亡。没有可用的治病方法 毒品。在95%的ALS患者中，受影响的神经元显示TDP-43的胞浆积聚(交互作用 反应元件DNA/RNA结合蛋白，43 kDa)。TDP-43是一种普遍表达的剪接因子 通常定位于细胞核。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TDP-43胞浆内的错误定位和聚集，概括了关键 人类身上可见的病理变化。编码TDP-43(TARDBP)和几个类似基因的突变 RNA结合蛋白(RBP)(例如，FUS、hnRNPA2B1、MATR3)可引起家族性ALS以及相关的ALS，通常 共病病额颞叶痴呆(FTD)。RBP功能异常如何导致ALS和FTD是一个 正在进行的研究领域；然而，几项证据表明，RNA剪接的全球破坏 稳定是一个中心主题。 我们和其他人确定过表达RNA解旋酶UPF1(UPF1)可以改善 TDP43和FUS体内和体外毒性模型的毒性。这项建议旨在澄清 UPF1介导的神经保护机制，特别是在TDP-43毒性模型中。UPF1是必备的 无意义介导衰变(NMD)的组成部分，这是一个重要的RNA监测程序。由于TDP-43的毒性 调节失调与其结合RNA的能力密切相关，该提案侧重于潜在的相互作用 在UPF1和TDP-43底物之间。我推测UPF1通过以下方式挽救TDP-43的毒性：(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 两者兼而有之。这些调查不仅将为我提供机会来开发基本的 在实验设计、生物信息学和交流方面的科学技能，但也承诺提供新的见解 UPF1介导的神经保护的治疗潜力。最终，这些机会将是 作为一名成功的神经学家和致力于这项研究的神经学家，我在独立的道路上发挥了重要作用 关于神经状况、疾病机制和治疗干预的研究。

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.