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

这项建议试图确定TDP-43蛋白聚集如何失调P-Body功能 神经细胞，并随后产生神经毒性。TDP-43的细胞质聚集已被报道 几乎每一种与年龄相关的神经退行性疾病，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，90%的ALS。它还定义了最近的 在最年长的老年人中公认的AD样痴呆，一种名为边缘主导年龄的AD样综合征- 相关的TDP-43脑病(晚期)。我们已经发现TDP-43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 肌萎缩侧索硬化症患者死后脊髓运动神经元。P小体是无膜的细胞质 核糖核蛋白(RNP)颗粒，由参与翻译抑制的RNA和蛋白质复合体组成 和信使核糖核酸的衰变。神经元在胞体内携带大量的P小体。我们假设TDP-43 聚集通过破坏P小体的形态和功能而引起神经元毒性。我们的 该方案具有很高的创新性，因为TDP-43蛋白病变是如何调节其他无膜性LLP的 细胞器在体内还没有报道。我们建议使用尖端成像、蛋白质组学和测序 测定神经元P小体的蛋白质和RNA组成及其反应变化的方法 对TDP-43体内聚集的影响。我们将首先确定TDP-43胞质聚集体是如何启动P-小体的 拆解，然后确定携带TDP-43聚集体的神经元的RNA代谢变化或 有缺陷的P形体。最后，也是重要的一点，我们将确定P小体蛋白和RNA是否可以作为 AD相关痴呆的病理标志物，如晚期。

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.