TDP-43 acetylation as a pathogenic modification in ALS & related proteinopathies

描述（由申请人提供）：肌萎缩性侧索硬化症（ALS）是一种毁灭性的运动神经元疾病，生存率为3-5年，无疾病改善疗法。TAR 43kD DNA结合蛋白（TDP-43）是一种核RNA和DNA结合蛋白，在大多数ALS患者以及一部分痴呆患者（伴有TDP-43病理的额颞叶变性，或FTLD-TDP）的脑和脊髓中异常聚集，将ALS和FTLD-TDP置于称为TDP-43蛋白病变的疾病谱系中。尽管TDP-43的病理与疾病的发生和进展有关，但人们对TDP-43如何聚集导致进行性神经退行性变知之甚少。我的长期目标是揭示促进TDP-43聚集的致病机制，这将为未来治疗这些使人衰弱的疾病提供见解。翻译后修饰与神经退行性疾病的进展有关。利用我在乙酰化生物学方面的背景，我先前证明了tau蛋白的乙酰化促进阿尔茨海默病和相关tau病的缠结形成（Nat common . 2011~2:252）。我现在已经证明了TDP-43受到乙酰化的影响，从而强调了一种新的TDP-43修饰，它可能与ALS和相关的蛋白质病变有关。该提案的中心假设是确定TDP-43的乙酰化是否促进聚集和神经变性。为了实现这一目标，我将从指导实验室获得神经病理学方面的专业知识，分析ALS和FTLD-TDP死后脑和脊髓中TDP-43的乙酰化，以及以TDP-43病理和神经变性为特征的TDP-43转基因小鼠。为了直接确定乙酰化的TDP-43是否会促进疾病，我们将对表达乙酰化的TDP-43的原代神经元培养和转基因小鼠进行病理标记、毒性和神经退行性评估，以概括人类TDP-43蛋白病变。在确定了TDP-43乙酰化与疾病的相关性之后，独立阶段将利用体外和基于细胞的方法来研究乙酰化在导致TDP-43与靶基因和rna结合受损，导致TDP-43功能丧失中的生物学意义。最后，作为一名独立研究者，我将利用K99期训练在神经退行性疾病中产生一个高乙酰化TDP-43的小鼠模型，并确定大脑和骨骼肌的ALS表型。这些创新研究将强调TDP-43乙酰化是与ALS和相关TDP-43蛋白病变进展相关的关键修饰。

DESCRIPTION (provided by applicant): Amyotrophic Lateral Sclerosis (ALS) is a devastating motor neuron disease with a 3-5 year survival rate and no disease-modifying therapies. TAR DNA-binding protein of 43kD (TDP-43) is a nuclear RNA and DNA binding protein that becomes abnormally aggregated in the brain and spinal cord of most ALS patients as well as a subset of dementia patients (frontotemporal lobar degeneration with TDP-43 pathology, or FTLD-TDP), placing ALS and FTLD-TDP within a spectrum of diseases known as TDP-43 proteinopathies. Although TDP-43 pathology has been implicated in disease onset and progression, little is known about how TDP-43 becomes aggregated leading to progressive neurodegeneration. My long-term goal is to uncover the pathogenic mechanisms that promote TDP-43 aggregation, which will provide insights for future therapies against these debilitating diseases. Post-translational modifications have been implicated in the progression of neurodegenerative diseases. Using my background in acetylation biology, I previously demonstrated that acetylation of the tau protein promotes tangle formation in Alzheimer's disease and related tauopathies (Nat Commun. 2011~2:252). I have now demonstrated that TDP-43 is subject to acetylation, thus highlighting a new TDP-43 modification that is potentially linked to ALS and related proteinopathies. The centra hypothesis of this proposal is to determine whether acetylation of TDP-43 promotes aggregation and neurodegeneration. To accomplish this goal, I will acquire expertise in neuropathology from the mentoring laboratory and analyze TDP-43 acetylation in ALS and FTLD-TDP post-mortem brain and spinal cord as well as TDP-43 transgenic mice characterized by TDP-43 pathology and neurodegeneration. To directly determine whether acetylated TDP-43 promotes disease, primary neuronal cultures and transgenic mice expressing acetylated TDP-43 will be evaluated for pathological hallmarks, toxicity, and neurodegeneration that recapitulate human TDP-43 proteinopathies. Having established the disease relevance of TDP-43 acetylation, the independent phase will utilize in vitro and cell-based approaches to investigate the biological significance of acetylation in causing impaired TDP- 43 binding to target genes and RNAs, leading to a TDP-43 loss of function. Finally, as an independent investigator, I will utilize K99 phase training in neurodegenerative disease to generate a mouse model of hyper-acetylated TDP-43 and determine the ALS phenotype in both brain and skeletal muscle. These innovative studies will highlight TDP-43 acetylation as a critical modification linked to the progression of ALS and related TDP-43 proteinopathies. PUBLIC HEALTH RELEVANCE: Amyotrophic Lateral Sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP) represent two major TDP-43 proteinopathies with no effective treatment strategies. The proposed studies will provide insights into the underlying mechanism of TDP-43 aggregation and highlight acetylated TDP-43 as a therapeutic target and potential biomarker for patients with ALS and related TDP-43 proteinopathies.