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（由申请人提供）：自噬/溶酶体途径功能障碍在年龄相关疾病（如神经变性）的发展中具有病理学意义。在秀丽隐杆线虫中，一些长寿模型依赖于增加的自噬来延长寿命，这表明自噬在衰老中起着关键作用。当自噬的负调节因子——营养传感器TOR被抑制时，动物也可以享受更长的寿命。然而，自噬如何介导其有益作用尚不清楚。我们最近报道了自噬可以通过过度表达推测的溶酶体脂肪酶LIPL-4来诱导，从而导致显著的寿命延长、脂肪分解增强和TOR信号改变，这表明脂质代谢、自噬和衰老之间存在联系。LIPL-4与人类溶酶体酸性脂肪酶（LAL）具有很强的同源性，LAL是通过自噬水解胆固醇的关键酶。值得注意的是，lal介导的胆固醇加工受损与阿尔茨海默病的发展有关。我的新结果表明，过表达LIPL-4可以改善秀丽隐杆线虫阿尔茨海默病模型中的A¿毒性。因此，本研究将验证LIPL-4类似于LAL介导溶酶体脂质水解的假设，并旨在阐明LIPL-4如何调节自噬和减轻A¿毒性。在Aim 1中，我将确认LIPL-4在细胞内的作用位点，并确定其与TOR信号传导的关系。在Aim 2中，我将测试在秀丽隐杆线虫中LIPL-4和LAL是否在功能上可互换。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阿尔茨海默病发病的延迟。我还将执行高通量筛选（HTS），以发现新的和特定的候选激活lal介导的脂肪分解，作为对抗神经退行性变的策略。通过确定溶酶体脂解在衰老中的作用，我的建议将为发现预防阿尔茨海默病的新药提供基础。为期2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。与HTS兼容的基于细胞的检测报告系统将用于寻找增强LAL表达的新药。为期3年的独立R00期将有助于进一步了解LIPL-4在溶酶体脂解、脂质信号传导和衰老中的作用，并将其扩展到脂质动力学、代谢和蛋白质稳态的研究中。LAL的主要候选激活剂将在秀丽隐杆线虫的阿尔茨海默病模型和细胞培养模型中进行验证。该提案包括尖端的方法，如蛋白质组学分析，CARS显微镜和HTS结合秀丽隐杆线虫疾病模型的创新使用。综上所述，K99/R00基金为我提供了一个学习新技术和发展专业技能的独特机会，使我能够成功地过渡到一个独立的老龄化研究科学家。