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

TDP-43病理学首先在肌萎缩侧索硬化症（ALS）和额颞叶脑梗死（EAE）中被发现。 但后来在包括阿尔茨海默氏症在内的其他无法治愈的神经系统疾病中发现了这种疾病 疾病（AD）。其特征在于溶解度降低、过度磷酸化和异常积聚。 TDP-43在胞质区室中，这导致其核消耗。尽管付出了巨大的努力， 尽管我们研究了TDP-43的功能，但我们仍然对TDP-43的分子事件了解甚少。 TDP-43发病机制。例如，对介导其的分子靶点和机制知之甚少。 病理级联，以及哪些和多少途径协调疾病。此外，最近的研究 提示TDP-43可能通过调节Aβ42斑块形成和tau蛋白表达，在AD发病机制中发挥作用 聚合来因此，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Aβ42和tau病理学的潜在相互作用。为了解决这个问题，我们最近 进行了一个无偏见的功能丧失筛选，寻找突变TDP-43毒性的修饰剂， 果蝇的眼睛为了做到这一点，我们使用了下一代收集的6，261个针对人类同源物的RNA系 发现了375个修饰子，包括100多个抑制子。我们的假设是， 这些修饰剂的功能分析，包括在其他神经退行性模型中的治疗挑战，将 有助于解构和识别最相关的病理级联。因此，本申请旨在 验证、分类和优先排序最好的TDP-43抑制器在这个星座的修改器（目的 1）。此外，我们还将确定最佳候选药物及其组合的治疗潜力， FTLD、ALS和AD的其他模型（目标2）。由于TDP-43、Aβ42和tau在体内的共同操纵是不可能的。 由于这些因素之间的积极协同毒性，很难研究，我们开发了一种新的 光遗传学表达系统绕过这一限制。这个新系统允许前所未有的 基因表达的时空控制响应于光的数量，持续时间和方向，因此，我们将 使用它来大大增加这些蛋白质如何使用体内和体外范例相互作用的知识 (Aim 3）。综合起来看，这些实验意义重大，因为它们将把复杂的 介导TDP-43蛋白质病的机制，并将为开发 新的治疗策略。此外，我们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的检测结果

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.