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， 脊髓和皮层运动神经元的丧失ALS的特征在于显著的 疾病发作和患者表现的异质性。在过去的二十年里，突变 在超过35种不同的基因中，已经发现它们在家族形式的发展中起着因果作用。 ALS（fALS）;然而，fALS仅占所有ALS病例的约10%。其余 90%的患者患有散发性ALS（sALS），无家族病史， 发病原因。不管所有这些遗传和致病的复杂性， 几乎每一个ALS患者（fALS和sALS）都有一个共同的神经病理学， 一种称为TAR DNA结合蛋白的43 kDa蛋白质的异常细胞质内含物形式 （TDP-43）发现于神经系统的退化区域。从以下研究中得出的见解： fALS连锁突变涉及疾病发展中的应激颗粒功能障碍， 应激颗粒可能直接调节TDP-43聚集的确切机制 仍不清楚通过利用新的光遗传学方法诱导TDP-43包涵体或 功能应力颗粒，我们可以操纵这些过程在以前无法达到的 控制水平。这些实验将探索应激颗粒功能障碍对 TDP-43神经毒性。我们假设应力颗粒动力学中的扰动 导致ALS中神经毒性TDP-43聚集。我们将首先调查的贡献 应力颗粒形成光诱导TDP-43内含物。然后我们将确定是否慢性或 持续的应激颗粒形成引发TDP-43蛋白质病。最后，我们将执行一个 全基因组RNAi筛选，以确定防止TDP-43包含的新途径 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.