Validating Secretory Autophagy as a Therapeutic Strategy for Diverse Forms of ALS and FTD

ALS、FTD和阿尔茨海默氏症是一种复杂的疾病，每一种都是由许多不同的遗传病因引起的。 尽管针对特定原因突变(例如SOD1ASO)的治疗策略可能被证明是有效的 对于个别形式的ALS和FTD，这些方法无法解决绝大多数情况 有未知的遗传病因。此外，考虑到大量不同的基因可能对 ALS和FTD以及每种遗传形式都相对罕见的事实，这一策略可能很难实施 适用于所有情况。因此，迫切需要新的治疗策略来挽救多种形式的 ALS和FTD，特别是那些遗传病因不明的人。找出新的治疗靶点 营救多种形式的肌萎缩侧索硬化症，我们进行了无偏见的化学筛选，以寻找可以营救的目标 多发性C9ORF72和散发性ALS患者IPSC运动神经元的变性抗肿瘤药物 PIKfyve激酶是所有患者中最有效和最有效的化合物之一。 令人惊讶的是，数据显示，PIKfyve抑制通过阻断自噬小体来挽救神经退化- 溶酶体融合，诱导分泌性自噬清除错误折叠的蛋白质，包括C9ORF72二肽 重复蛋白和TDP-43通过胞外分泌。错误折叠的蛋白质的积累可以诱导 神经元死亡，是神经退行性疾病的共同特征。尽管已有研究试图 刺激已知的蛋白稳定途径，包括蛋白小体和自噬，这些途径会下降 在老化过程中，可能很难有效地抢救。有趣的是，最近的研究表明，神经元使用 胞外体分泌作为第三种蛋白平衡途径。然而，目前还不清楚这条途径是否可以 用于治疗肌萎缩侧索硬化症和相关的神经退行性疾病。拟议研究的中心假设 这种分泌性自噬是防止ALS、FTD和 阿尔茨海默氏症与该领域的主流思维不同。评估这一假说至关重要，因为 在神经退化模型中，激活蛋白酶体和自噬的结果好坏参半。建议数 研究将1)证实分泌性自噬是PIKfyve抑制的治疗机制，2) 确定分泌性自噬在ALS、FTD和阿尔茨海默病患者中的有效性 3)在体内验证反义寡核苷酸抑制PIKfyve的效果。 这一应用程序试图通过验证分泌自噬的诱导作为一种 针对不同形式的ALS、FTD和阿尔茨海默病的高效治疗策略。这个 拟议的研究将把抑制PIKfyve和分泌性自噬作为关键的治疗方法 肌萎缩侧索硬化症和相关神经退行性疾病的靶点。更广泛地说，这种治疗策略可能 对其他由蛋白质异常堆积引起的疾病有效。

ALS, FTD, and Alzheimer’s are complex diseases that each result from many diverse genetic etiologies. Although therapeutic strategies that target specific causal mutations (e.g. SOD1 ASOs) may prove effective against individual forms of ALS and FTD, these approaches cannot address the vast majority of cases that have unknown genetic etiology. Moreover, given the large number of different genes that likely contribute to ALS and FTD and the fact that each genetic form is relatively rare, this strategy may be difficult to implement for all cases. Thus, there is a pressing need for new therapeutic strategies that rescue multiple forms of ALS and FTD, particularly those with unknown genetic etiologies. To identify new therapeutic targets that rescue multiple forms of ALS, we performed unbiased chemical screens to search for targets that can rescue the degeneration of iPSC motor neurons from multiple C9ORF72 and sporadic ALS patients. Inhibitors of PIKFYVE kinase were among the most potent and broadly-efficacious compounds across patient lines. Surprisingly, the data show that PIKFYVE inhibition rescues neurodegeneration by blocking autophagosome- lysosome fusion, which induces secretory autophagy to clear misfolded proteins including C9ORF72 dipeptide repeat proteins and TDP-43 through exosomal secretion. The accumulation of misfolded proteins can induce neuron death and is a common feature of neurodegenerative diseases. Although studies have sought to stimulate known proteostasis pathways including the proteosome and autophagy, these pathways decline during aging and may be difficult to rescue effectively. Intriguingly, recent studies have shown that neurons use exosomal secretion as a third proteostasis pathway. However, it remains unknown if this pathway can be harnessed to treat ALS and related neurodegenerative diseases. The central hypothesis of the proposed study that secretory autophagy is one of the most potent ways to prevent neurodegeneration in ALS, FTD, and Alzheimer’s disease differs from mainstream thinking in the field. Evaluating this hypothesis is crucial because activating the proteasome and autophagy has had mixed results in neurodegeneration models. The proposed study will 1) confirm that secretory autophagy is the therapeutic mechanism of PIKFYVE inhibition, 2) determine the efficacy of secretory autophagy in ALS, FTD, and Alzheimer’s disease patient-derived neurons, and 3) validate the efficacy of PIKFYVE suppression with antisense oligonucleotides in vivo. This application seeks to shift current research by validating the induction of secretory autophagy as a highly effective therapeutic strategy for diverse forms of ALS, FTD, and Alzheimer’s disease. The proposed study will establish PIKFYVE suppression and secretory autophagy as critical therapeutic targets for ALS and related neurodegenerative diseases. More broadly, this therapeutic strategy may be effective for other diseases driven by aberrant protein accumulation.