An optogenetic approach to establish the interplay between stress granules and TDP-43 proteinopathy in ALS/FTD

肌萎缩侧索硬化症(ALS)是一种进行性、致命性神经退行性疾病。 由于脊髓和皮质运动神经元的丧失。ALS的特点是显著的 疾病发病和患者表现的异质性。在过去的二十年里，突变 在超过35个不同的基因中，已经发现了与家族形式发展有关的原因 ALS(FALS)；然而，FALS仅占所有ALS病例的约10%。剩下的 90%的患者患有散发性肌萎缩侧索硬化症(SALS)，无家族病史，且未知 致病原因。不管所有这些遗传和致病的复杂性，值得注意的是 几乎每个ALS患者(FALS和SALS)都有共同的神经病理 43 kDa TAR DNA结合蛋白胞质异常包涵体的形态 (TDP-43)发现于神经系统退行性变的区域。从研究得出的见解 FALS相关突变与疾病发展中的应激颗粒功能障碍有关，但 应激颗粒直接调节TDP-43聚集的确切机制 目前仍不清楚。通过利用一种新的光遗传方法来诱导TDP-43包裹体或 功能应激颗粒，我们可以在以前无法达到的情况下操纵这些过程 控制级别。这些实验将探索应激颗粒功能障碍对 TDP-43包涵体神经毒性。我们假设应力颗粒动力学中的微扰 促进肌萎缩侧索硬化症的神经毒性TDP-43聚集。我们将首先调查一下 应激颗粒对光诱导的TDP-43包裹体的影响。然后我们将确定慢性或 持续应激颗粒形成引发TDP-43蛋白病变。最后，我们将表演一个 全基因组RNAi筛选以识别保护TDP-43包涵体的新途径 毒性，并评估这种保护是否依赖于应激颗粒调节。

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disorder marked by loss of motor neurons of the spinal cord and cortex. ALS is characterized by significant heterogeneity in disease onset and patient presentation. Over the last twenty years, mutations in over 35 different genes have been uncovered as causal in the development of familial forms of ALS (fALS); however, fALS only accounts for roughly 10% of all ALS cases. The remaining 90% of patients suffer from sporadic ALS (sALS), with no family history of disease and unknown causes of pathogenesis. Regardless of all this genetic and pathogenic complexity, remarkably nearly every single ALS patient (both fALS and sALS) share a common neuropathology in the form of aberrant cytoplasmic inclusions of a protein called TAR DNA-binding protein of 43 kDa (TDP-43) found in degenerating regions of the nervous system. Insight drawn from studies of fALS-linked mutations have implicated stress granule dysfunction in disease development, but the exact mechanisms by which the stress granules may directly regulate TDP-43 aggregation remains unclear. By utilizing a novel optogenetic approach to induce either TDP-43 inclusions or functional stress granules, we can manipulate these processes at a previously unattainable level of control. These experiments will explore the contribution of stress granule dysfunction to TDP-43 inclusion neurotoxicity. We hypothesize that perturbations in stress granule dynamics contribute to neurotoxic TDP-43 aggregation in ALS. We will first investigate the contribution of stress granules to light-induced TDP-43 inclusions. We will then determine if chronic or persistent stress granule formation initiates TDP-43 proteinopathy. Finally, we will perform a genome-wide RNAi screen to identify novel pathways that protect against TDP-43 inclusion toxicity and assess whether this protection is dependent on stress granule regulation.