Determine the neurotoxicity of RNA metabolism dysfunction caused by cytoplasmic TDP-43 aggregates

该提案旨在确定TDP-43蛋白聚集体如何在哺乳动物中失调P体功能。 神经元并随后产生神经毒性。TDP-43的细胞质聚集已经在 几乎所有年龄依赖性神经退行性疾病，包括>40%的额颞叶痴呆（FTD）， 在阿尔茨海默病（AD）患者的海马神经元中，在>90%的ALS中。它还定义了一个最近 在最年长的老年人中公认的AD样痴呆，一种名为边缘优势年龄的AD样综合征， TDP-43相关脑病（LATE）。我们已经确定，TDP-43细胞质聚集体调节 神经元样细胞中RNA加工体（P体）的液-液相分离（LLPS）， ALS患者死后脊髓运动神经元。P小体是无细胞膜的 核糖核蛋白（RNP）颗粒，由参与翻译抑制的RNA和蛋白质复合物组成 和mRNA衰变。神经元在索马中携带大量的P体。我们假设TDP-43 聚集通过破坏P体的形态和功能而引起神经元毒性。我们 该提案具有高度创新性，因为TDP-43蛋白质病如何调节其他无膜细胞的LLPS， 细胞器尚未在体内报道。我们建议使用最先进的成像，蛋白质组学，和测序 确定神经元P体的蛋白质和RNA组成及其在响应中如何变化的方法 TDP-43在体内的聚集。我们将首先确定TDP-43细胞质聚集体如何启动P体 拆卸，然后确定携带TDP-43聚集体的神经元中的RNA代谢变化，或 有缺陷的P体最后也是重要的是，我们将确定P体蛋白和RNA是否可以作为 AD相关痴呆的病理标志物，如LATE。

This proposal seeks to determine how TDP-43 protein aggregates dysregulate P-body function in neurons and subsequently produce neurotoxicity. Cytoplasmic aggregation of TDP-43 has been reported in nearly every age-dependent neurodegenerative disease, including in >40% of frontotemporal dementia (FTD), in the hippocampal neurons of Alzheimer’s disease (AD) patients, in >90% of ALS. It also defines a recently recognized AD-like dementia in the oldest elderly, an AD-like syndrome named Limbic-predominant Age- related TDP-43 Encephalopathy (LATE). We have identified that TDP-43 cytoplasmic aggregates regulate the liquid-liquid phase separation (LLPS) of RNA processing bodies (P-bodies) in neuron-like cells and postmortem spinal cord motor neurons in ALS patients. P-bodies are cytoplasmic membraneless ribonucleoprotein (RNP) granules composed of RNAs and protein complexes involved in translational repression and mRNA decay. Neurons carry a high number of P-bodies in the soma. We hypothesize that TDP-43 aggregation causes neuronal toxicity by disrupting the morphology and function of P-bodies. Our proposal is highly innovative because how TDP-43 proteinopathy regulates the LLPS of other membraneless organelles has not been reported in vivo. We propose to use cutting-edge imaging, proteomic, and sequencing approaches to determine the protein and RNA composition of neuronal P-bodies and how it changes in response to TDP-43 aggregation in vivo. We will first determine how TDP-43 cytoplasmic aggregates initiate P-body disassembly and then determine the RNA metabolism change in neurons carrying TDP-43 aggregates or defective P-bodies. Lastly and importantly, we will determine whether P-body proteins and RNA can serve as pathological markers for AD-related dementia, such as LATE.