Role of LIPL-4 in lysosomal lipolysis and aging

LIPL-4 在溶酶体脂肪分解和衰老中的作用

• 批准号: 8509547
• 负责人: Louis Rene Lapierre
• 金额: $ 12.99万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8509547
• 关键词: Acid Lipase; Address; Age of Onset; Aging; Alzheimer' s Disease; Alzheimer' s disease model; Animals; Autophagocytosis; Autophagosome; Biological Assay; Caenorhabditis elegans; Cell Culture Techniques; Cells; Chemicals; Cholesterol; Cholesterol Esters; Coupled; Data; Development; Disease; Disease model; Enzymes; Functional disorder; Genes; Genetic Screening; Grant; Homeostasis; Human; Hydrolysis; Impairment; Insulin; Lead; Learning; Link; Lipase; Lipids; Lipolysis; Longevity; Lysosomes; Mammalian Cell; Mediating; Metabolism; Methods; Microscopy; Modeling; Molecular; Mus; Nematoda; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Nutrient; Organelles; Organism; Paralysed; Pathway interactions; Pharmaceutical Preparations; Phase; Physiological; Process; Proteins; Proteomics; Publishing; Recycling; Reporter; Reporting; Research; Risk; Role; Scientist; Senile Plaques; Signal Pathway; Signal Transduction; Sirolimus; Site; Solutions; System; Testing; Therapeutic; Toxic effect; Translating; Vesicle; Work; Yeasts; age related; aging population; base; cholesterol trafficking; fly; high throughput screening; innovation; insulin signaling; lipid metabolism; new technology; novel; prevent; public health relevance; research study; sensor; skills; sterol esterase; therapeutic target; transcription factor

DESCRIPTION (provided by applicant): Dysfunctions in the utophagy/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 A¿ 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 A¿ 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.

描述（由适用提供）：统一/溶酶体途径中的功能障碍在与年龄相关疾病（例如神经变性）的发展中具有病理意义。在秀丽隐杆线虫中，几种寿命模型依靠自噬增加了寿命的延长，这表明自噬在衰老中起着至关重要的作用。当抑制营养传感器TOR（一种自动噬菌体的负调节剂）时，动物也可以享受更长的寿命。尽管如此，自噬如何介导其有益效果的方式却很少理解。我们最近报道说，可以通过过度表达假定的溶酶体脂肪酶Lipl-4来诱导自噬，从而导致寿命延长，增强的脂解和TOR信号改变，这表明脂质代谢，自动噬菌体，自噬和衰老之间存在联系。 LIPL-4显示与人类溶酶体脂肪酶（LAL）的强同源性，这是通过自噬水解胆固醇水解的关键酶。值得注意的是，LAL介导的胆固醇加工受损与阿尔茨海默氏病的发展有关。我的新结果表明，过度表达Lipl-4在阿尔茨海默氏病的秀丽隐杆线虫模型中改善了毒性。因此，该提案将检验以下假设：LIPL-4与LAL相似，介导溶酶体脂质水解，并将旨在阐明LIPL-4如何调节自噬和减轻毒性。在AIM 1中，我将确认LIPL-4的细胞内作用部位，并确定其与TOR信号的关系。在AIM 2中，我将测试Lipl-4和LAL是否在秀丽隐杆线虫中可以互换。 LIPL-4诱导自噬和调节衰老的作用机制也将被阐明。在AIM 3中，我将研究Lipl-4如何介导秀丽隐杆线虫中阿尔茨海默氏病的延迟。我还将执行一个高通量屏幕（HTS），以发现激活LAL介导的脂肪分解的新颖和特定候选者，作为一种反对神经变性的策略。通过确定溶酶体脂解在衰老中的作用，我的建议将为可以发现新的药物提供一个基础，以防止阿尔茨海默氏病。两年的博士后K99阶段将包括LIPL-4在溶酶体功能，脂质代谢和衰老中的作用的表征。基于细胞的测定报告基因系统将与HTS兼容，以找到新的药物来增强LAL表达。为期3年的独立R00期将进一步了解LIPL-4在溶酶体脂解，脂质信号传导和衰老中的作用，并扩展到有关脂质动力学，代谢和蛋白质的研究。 LAL的主要候选激活因子将使用秀丽隐杆线虫和细胞培养模型中的阿尔茨海默氏病模型进行验证。该建议包括尖端方法，例如蛋白质组学分析，汽车显微镜和HTS，并结合了秀丽隐杆线虫中疾病模型的创新使用。总而言之，K99/R00赠款是我学习新技术并发展我的专业技能的独特机会，以成功地过渡到衰老研究领域的独立科学家。