Role of LIPL-4 in lysosomal lipolysis and aging

项目总结 自噬/溶酶体途径的功能障碍在发育过程中具有重要的病理学意义 与年龄相关的疾病，如神经退行性变。在线虫中，几个长寿模型依赖于 自噬增加可以延长寿命，这表明自噬在衰老过程中起着关键作用。动物 当营养传感器TOR，自噬的负向调节器，被 被禁止了。尽管如此，自噬是如何调节其有益影响的，人们却知之甚少。我们最近 报道称，过度表达溶酶体脂肪酶LIPL-4可以诱导自噬。 导致寿命显著延长，脂肪分解增强，并改变了TOR信号， 这表明脂肪代谢、自噬和衰老之间存在联系。LIPL-4具有很强的同源性 与人溶酶体酸性脂肪酶(LAL)，一个通过自噬的胆固醇水解酶的关键酶。 值得注意的是，LAL介导的胆固醇处理受损与高血压的发生有关 阿尔茨海默氏症。我的新结果表明，过表达LIPL-4可以减轻Aβ在C。 阿尔茨海默病的优雅动物模型。因此，这一提议将检验LIPL-4， 与LAL类似，介导溶酶体脂水解酶，旨在阐明LIPL-4是如何调节的 自噬和减轻β毒性。在目标1中，我将确认LIPL-4和LIPL-4的细胞内作用部位 确定其与TOR信号的关系。在目标2中，我将测试LIPL-4和LAL是否在功能上 在线虫中可互换的。LIPL-4诱导自噬的作用机制 对衰老的调节也将被阐明。在目标3中，我将研究LIPL-4如何调节 秀丽线虫阿尔茨海默病的发病。我还将执行高通量筛选(HTS)以 发现激活LAL介导的脂解作用的新的和特定的候选者，作为对抗 神经退行性变。通过确定溶酶体脂肪分解在衰老中的作用，我的建议将提供一种 在此基础上可以发现预防阿尔茨海默病的新药。 为期2年的博士后K99阶段将包括对lipl-4在 溶酶体功能、脂代谢和衰老。基于细胞的检测报告系统兼容 HTS将被用于寻找增强LAL表达的新药。为期3年的独立R00阶段 将有助于进一步了解Lipl-4在溶酶体脂解、脂质信号和衰老中的作用 拓展对脂类动力学、新陈代谢和蛋白质平衡的研究。LAL的主要候选激活剂 将在线虫和细胞培养模型中使用阿尔茨海默病模型进行验证。这项建议 包括前沿方法，如蛋白质组分析、CARS显微镜和高温超导相结合 通过对线虫疾病模型的创新使用。总而言之，K99/R00赠款代表着 这是我学习新技术和发展专业技能的难得机会 转变为老龄研究领域的独立科学家。

PROJECT SUMMARY Dysfunctions in the autophagy/lysosomal pathway are pathologically significant in the development of age-related diseases, such as neurodegeneration. In C. elegans, several longevity models rely on increased autophagy for lifespan extension, suggesting a critical role for autophagy in aging. Animals can also enjoy longer lifespan when the nutrient-sensor TOR, a negative regulator of autophagy, is inhibited. Nonetheless, how autophagy mediates its beneficial effects is poorly understood. We recently reported that autophagy could be induced by over-expressing the putative lysosomal lipase LIPL-4, which resulted in a significant lifespan extension, enhanced lipolysis and altered TOR signaling, suggesting a link between lipid metabolism, autophagy and aging. LIPL-4 displays strong homology with human lysosomal acid lipase (LAL), a key enzyme in the hydrolysis of cholesterol via autophagy. Notably, impaired LAL-mediated cholesterol processing has been linked to the development of Alzheimer's disease. My new results show that over-expressing LIPL-4 ameliorates Aβ toxicity in a C. elegans model of Alzheimer's disease. Therefore, this proposal will test the hypothesis that LIPL-4, similar to LAL, mediates lysosomal lipid hydrolysis and will aim to elucidate how LIPL-4 modulates autophagy and mitigates Aβ toxicity. In Aim 1, I will confirm the intracellular site of action of LIPL-4 and determine its relationship to TOR signaling. In Aim 2, I will test whether LIPL-4 and LAL are functionally interchangeable in C. elegans. The mechanism of action by which LIPL-4 induces autophagy and modulates aging will also be elucidated. In Aim 3, I will investigate how LIPL-4 mediates a delay in the onset of Alzheimer's disease in C. elegans. I will also perform a high-throughput screen (HTS) to discover novel and specific candidate that activates LAL-mediated lipolysis, as a strategy against neurodegeneration. By determining the role of lysosomal lipolysis in aging, my proposal will provide a basis on which novel drugs can be discovered to prevent Alzheimer's disease. The 2-year postdoctoral K99 phase will consist in the characterization of the role of LIPL-4 in lysosomal function, lipid metabolism and aging. Cell-based assay reporter systems compatible with HTS will be used to find novel drugs to enhance LAL expression. The 3-year independent R00 phase will serve to further understand the role of LIPL-4 in lysosomal lipolysis, lipid signaling and aging and expand into studies on lipid dynamics, metabolism and proteostasis. Lead candidate activators of LAL will be validated using Alzheimer's disease model in C. elegans and cell culture models. This proposal includes cutting-edge approaches, such as proteomic analyses, CARS microscopy and HTS combined with the innovative use of disease models in C. elegans. In summary, the K99/R00 grant represents a unique opportunity for me to learn new technologies and develop my professional skills to successfully transition into an independent scientist in aging research.