Synergy of lipolysis and lipophagy in alcoholic liver disease

脂肪分解和脂肪吞噬在酒精性肝病中的协同作用

• 批准号: 10489818
• 负责人: Micah Schott
• 金额: $ 24.9万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-20 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10489818
• 关键词: Acid Lipase; Address; Adipocytes; Adipose tissue; Adrenergic Agents; Advisory Committees; Affect; Alcohol consumption; Alcoholic Fatty Liver; Alcoholic Liver Diseases; Alcoholic beverage heavy drinker; Alcohols; Animal Model; Autophagocytosis; Autophagosome; Biochemistry; Bioinformatics; Biological; Biology; Catabolism; Cells; Cholesterol; Cirrhosis; Clinic; Committee Members; Complement; Complex; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Development; Disease Progression; Elderly; Endosomes; Environment; Enzymes; Ethanol; Event; Fatty Liver; Fibrosis; Future; Gastroenterology; Genetic Transcription; Goals; Hepatic; Hepatitis; Hepatocyte; Hepatology; Hydrolysis; Impairment; Knowledge; Lead; Lipase; Lipids; Lipolysis; Liver; Lysosomes; Malignant Neoplasms; Manuscripts; Mass Spectrum Analysis; Mediating; Membrane; Mentors; Microscopy; Multivesicular Body; Obesity; Organelles; Outcome; Pathway interactions; Peripheral; Pharmacology; Pharmacotherapy; Phase; Phosphotransferases; Positioning Attribute; Process; Progressive Disease; Protein Kinase; Protein phosphatase; Proteins; Proteome; Proteomics; Publishing; Regulation; Research; Rodent Model; Role; Schools; Signal Transduction; Sorting - Cell Movement; Surface; Testing; Training; Triglycerides; Vesicle; Work; base; cell type; chronic alcohol ingestion; combat; comparative; in vivo; insight; liver injury; multidisciplinary; novel; problem drinker; protein activation; public health relevance; receptor; recruit; response; sterol esterase; synergism; trafficking; transcription factor; uptake

Project Summary/Abstract My long-term objective is to discover new cellular mechanisms that contribute to alcoholic liver disease (ALD), a progressive disease leading to non-reversible stages that can be fatal. One of the early and reversible precursors of ALD is alcoholic steatosis, in which large triglyceride and cholesterol-rich lipid droplets (LDs) accumulate within hepatocytes, the main functional cell type of the liver. While LDs are believed to be central to the progression of ALD, the cellular mechanisms whereby alcohol disrupts the breakdown of these organelles are poorly understood. To address this important gap in knowledge, this proposal will define the synergy between two seemingly-distinct processes of lipid droplet catabolism: lipolysis, which utilizes the cAMP pathway to activate and recruit cytosolic lipases to the LD surface, and lipophagy, which utilizes membrane trafficking events that lead to LD breakdown by lysosomal lipases. Preliminary data suggest that lipolysis and lipophagy machinery target discrete, size-based LD subpopulations, and that small LDs are targeted for direct engulfment by multivesicular bodies (MVBs) for catabolism through the late endosomal pathway. Thus, the central hypothesis of this proposal is that EtOH disrupts a sequential mechanism whereby lipolysis acts on large LDs to reduce their size for direct uptake by endosomal microlipophagy. In Aim 1, I will determine the role of cytosolic lipases in protecting against ALD progression. In Aim 2, I will determine effect of EtOH on a sequential “lipolysis-to-lipophagy” pathway and define the mechanisms by which MVB/endosomes facilitate microlipophagy of small LDs. In Aim 3, I will integrate my previous expertise with this new knowledge and training to define novel cAMP signaling mechanisms that support lipolysis and lipophagy to combat alcoholic steatosis. The exceptionally strong research environment within Mayo Clinic’s Division of Gastroenterology and Hepatology is ideal for this training. To accomplish these aims, I will receive hands-on training in rodent models of chronic alcohol consumption, comparative proteomics, and bioinformatics. This new training complements my current skillset in cell signaling, microscopy, and biochemistry, and provides a multidisciplinary toolbox to comprehensively assess lipid catabolism in the liver. The proposed research will integrate my expertise in cAMP/PKA signaling mechanisms from my graduate school training with my postdoctoral expertise in lipid droplet biology and alcoholic steatosis. With the help of my mentor, Dr. Mark McNiven, along with a strong research team including two collaborators and four advisory committee members, I will have all the expertise and training needed to successfully accomplish these aims and transition to an independent research position. The results gained from the proposed research will provide a mechanistic understanding of lipid droplet catabolism in alcoholic fatty liver. Importantly, these studies will provide published research manuscripts and preliminary data in support of a future R01 proposal.

项目摘要/摘要 我的长期目标是发现有助于酒精肝的新的细胞机制 疾病（ALD），一种进行性疾病，导致可能致命的非可逆阶段。之一 ALD的早期和可逆前体是酒精脂肪变性，其中大甘油三酸酯和 富含胆固醇的脂质液滴（LDS）在肝细胞内积聚，这是主要功能细胞类型 肝脏。虽然LDS被认为是ALD进展的核心，但细胞 酒精破坏这些细胞器的机制很差 理解。为了解决知识中的这一重要差距，该建议将定义协同作用 在两个看似脱落的脂肪液滴分解代谢过程之间：脂解，利用了脂解 将胞质脂肪酶激活和募集到LD表面的营地途径，以及脂肪的途径 利用膜运输事件，导致溶酶体脂肪酶破裂。 初步数据表明，脂解和脂肪机械目标离散，基于尺寸的LD 亚群，小LD的目标是通过多细胞直接吞噬 （MVB）通过后期内体途径进行分解代谢。那是这一点的中心假设 提案是EtoH破坏了脂肪分解在大型LD上的顺序机制 减小其尺寸，可通过内体微寄生物直接吸收。在AIM 1中，我将确定 胞质脂肪酶在预防ALD进展中的作用。在AIM 2中，我将确定 ETOH在顺序的“脂肪分解到脂肪型”途径上，并定义了该机制 MVB/内体有助于小LDS的微量寄生虫。在AIM 3中，我将整合我以前的 通过这种新知识和培训来定义新颖的营地信号机制的专业知识 支持脂肪分解和脂噬，以对抗酒精脂肪变性。非常强大的研究 梅奥诊所胃肠病学和肝病学的环境是理想的选择 训练。为了实现这些目标，我将接受慢性啮齿动物模型的动手培训 饮酒，比较蛋白质组学和生物信息学。这个新的培训 完成我当前的细胞信号传导，显微镜和生物化学的技能，并提供 多学科工具箱，可全面评估肝脏中的脂质分解代谢。提议 研究将使我的专业知识在CAMP/PKA信号传导机制中纳入我的研究生 我在脂质液滴生物学和酒精脂肪变性方面的博士后专业知识的学校培训。 在我的导师Mark McNiven博士的帮助下，以及一个强大的研究团队，包括两个 合作者和四名咨询委员会成员，我将拥有所有的专业知识和培训 需要成功实现这些目标并过渡到独立研究 位置。从拟议的研究中得出的结果将提供机械 了解酒精脂肪肝中脂质滴分解代谢。重要的是，这些研究将 提供已发表的研究手稿和初步数据，以支持未来的R01 提议。