Deconstructing and challenging TDP-43 proteinopathies: from FTLD/ALS to Alzheimer's disease

TDP-43病理首先在肌萎缩侧索硬化症(ALS)和额颞叶被发现 变性(FTLD)，但后来在包括阿尔茨海默氏症在内的其他不可治愈的神经疾病中发现 疾病(AD)。它的特点是溶解度降低，过度磷酸化和异常堆积 TDP-43存在于胞浆内，导致胞核耗竭。尽管付出了相当大的努力 研究TDP-43的功能，我们仍然对潜在的分子事件了解很少 TDP-43的发病机制。例如，人们对其调节的分子靶点和机制知之甚少。 病理级联，以及哪些和多少条途径协调了这种疾病。此外，最近的研究 提示TdP-43可能通过调节A-β-42斑块形成和tau在AD发病机制中发挥作用。 聚合。因此，一个关键的挑战是确定能够阻断TDP的关键蛋白质和途径。 43毒性及其与并发的Aβ42和tau病理的潜在相互作用。为了解决这个问题，我们最近 进行了无偏功能丧失筛选，寻找突变型TDP-43毒性的修饰物 果蝇的眼睛。为了做到这一点，我们使用了下一代6261条RNA线来对抗人类同源物 发现了375个修饰子，其中包括100多个抑制子。我们的假设是，一个全面的 对这些修饰物的功能分析，包括在其他神经退行性模型中的治疗挑战，将 帮助解构和识别最相关的病理性级联反应。因此，本应用程序的目标是 验证、分类并确定该修饰物星座(AIM)中最好的TDP-43抑制因子的优先顺序 1)。此外，我们将定义排名靠前的候选人及其组合的治疗潜力 FTLD、ALS和AD的其他型号(目标2)。由于TDP-43、Aβ42和tau在体内的共同操作 由于这些因素之间的侵略性协同毒性很难研究，我们开发了一种新的 光遗传表达系统绕过了这一限制。这个新系统允许史无前例的 基因表达的时空控制对光量、持续时间和方向的响应，因此，我们将 利用它来显著增加关于这些蛋白质如何通过体内和体外范例相互作用的知识 (目标3)。总而言之，这些实验具有非常重要的意义，因为它们将梳理出复杂的 介导TDP-43蛋白病变的机制，将为TDP-43蛋白病的发展提供有价值的信息 新的治疗策略。此外，我们还将提供新的光遗传学工具，用于同时分析 多种神经毒性蛋白质，具有前所未有的分辨率。

TDP-43 pathology was first identified in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), but was later found in other incurable neurological disorders including Alzheimer's disease (AD). It is characterized by decreased solubility, hyper-phosphorylation and abnormal accumulation of TDP-43 in the cytosolic compartment, which results in its nuclear depletion. Despite considerable effort to investigate the function of TDP-43, we still have a very poor understanding of the molecular events underlying TDP-43 pathogenesis. For instance, little is known about the molecular targets and mechanisms mediating its pathological cascade, and which and how many pathways orchestrate the disease. Additionally, recent studies indicate that TDP-43 may also play a role in AD pathogenesis by regulating Aβ42 plaque formation and tau aggregation. A key challenge, therefore, is to identify critical proteins and pathways capable of blocking TDP- 43 toxicity and its potential interactions with concurrent Aβ42 and tau pathologies. To address this, we recently performed an unbiased loss-of-function screen searching for modifiers of mutant TDP-43 toxicity in the Drosophila eye. To do so, we used a next generation collection of 6,261 RNA lines against human homologues and found 375 modifiers, including more than 100 suppressors. Our hypothesis is that a comprehensive functional analysis of these modifiers, including therapeutic challenges in other neurodegenerative models, will help to deconstruct and identify the most relevant pathological cascades. Therefore, this application aims at validating, classifying and prioritizing the best TDP-43 suppressors among this constellation of modifiers (Aim 1). Additionally, we will define the therapeutic potential of the top candidates and their combinations in additional models of FTLD, ALS and AD (Aim 2). Since co-manipulation of TDP-43, Aβ42 and tau in vivo is very difficult to study due to the aggressive synergistic toxicity between these factors, we developed a new optogenetic expression system to bypass this limitation. This new system allows unprecedented spatiotemporal control of gene expression in response to light quantity, duration and direction and, thus, we will use it to substantially increase knowledge of how these proteins interact using in vivo and ex vivo paradigms (Aim 3). Taken together, these experiments are highly significant because they will tease apart the complex mechanisms mediating TDP-43 proteinopathies and will provide valuable information for the development of new therapeutic strategies. In addition, we will provide new optogenetic tools for the simultaneous analysis of multiple neurotoxic proteins with unprecedented resolution.