Interaction of the Microtubule Cytoskeleton and Perilipin-2 Regulates Hepatic Lipid Droplets - a Potential Therapeutic Target for Fatty Liver Disease

微管细胞骨架和 Perilipin-2 的相互作用调节肝脂滴 - 脂肪肝疾病的潜在治疗靶点

• 批准号: 10375465
• 负责人: Loretta L. Jophlin
• 金额: $ 16.58万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10375465
• 关键词: Affect; Aftercare; Alcohols; American; Basic Science; Benchmarking; Binding; Biogenesis; Biology; Catabolism; Cell Survival; Cessation of life; Cirrhosis; Clinic; Co-Immunoprecipitations; Coupled; Cytoskeleton; Data; Development Plans; Disease; Dynein ATPase; Equipment and Supplies; Fatty Liver; Fatty acid glycerol esters; Foundations; Funding; Future; Goals; Hepatic; Hepatocyte; Human; Imaging Techniques; Lead; Lipids; Lipolysis; Liver; Liver Failure; Liver diseases; Malignant neoplasm of liver; Measures; Medicine; Mentorship; Metabolism; Microtubules; Modeling; Mus; Mutation; Nocodazole; Organ; Organ Model; Organelles; Patient-Focused Outcomes; Patients; Positioning Attribute; Post-Translational Protein Processing; Pre-Clinical Model; Prevalence; Primary carcinoma of the liver cells; Process; Proteins; Regulation; Rehabilitation therapy; Research; Research Activity; Research Personnel; Risk; Scientist; Steatohepatitis; Structure; Testing; Therapeutic; Therapeutic Intervention; Time; Tissue Viability; Tissues; Training; Training Activity; Translating; Transplantation; Tubulin; Work; base; career; career development; cytotoxicity; ex vivo perfusion; fatty liver disease; high risk; improved; improved outcome; knock-down; liver function; liver transplantation; mutant; non-alcoholic fatty liver disease; nonalcoholic steatohepatitis; novel; perilipin; primary outcome; professor; targeted agent; therapeutic development; therapeutic evaluation; therapeutic target; trafficking; western diet

PROJECT SUMMARY/ABSTRACT The overall objective of this research is to target hepatocyte lipid droplets (LDs) for the development of therapeutic interventions for fatty liver disease. Hepatic steatosis, fat accumulation within hepatocyte LDs, is a key precursor for steatohepatitis which can lead to cirrhosis and hepatocellular cancer, necessitating liver transplantation. Unfortunately, hepatic steatosis also limits the number of donor livers acceptable for transplant as donor livers with severe steatosis have a high risk of primary nonfunction. As such, therapeutic strategies to reverse fatty liver are important for patients at risk for steatohepatitis and cirrhosis as well as to increase the donor pool of viable livers for transplantation. Our work focused on hepatocyte LDs herein shows three key observations: a) perilipin-2 (PLIN2), a LD-associated protein which regulates fat storage and utilization, co- localizes with and co-immunoprecipitates microtubules; b) microtubule disruption with nocodazole, a blunt microtubule targeting agent (MTA), uncouples PLIN2 from the LD, promotes LD fusion and yields delipidation (i.e. exocytotic secretion of LD contents) of steatotic hepatocytes with minimal cytotoxicity; and c) nocodazole promotes fat loss from ex vivo liver tissue with no effect on tissue viability. Based on these preliminary data, we propose the CENTRAL HYPOTHESIS that hepatocyte LDs are regulated by an interaction between PLIN2 and the microtubule cytoskeleton, and that this interaction is a potential therapeutic target to decrease the lipid burden of hepatocytes in fatty liver disease. Our SPECIFIC AIMS will test three hypotheses. FIRST, we will test the hypothesis that microtubules directly interact with LD-associated PLIN2. SECOND, we will test the hypothesis that microtubule perturbation increases lipolysis and leads to delipidation of steatotic hepatocytes. FINALLY, we will test the hypothesis that treatment of ex vivo steatotic liver tissue and ex vivo perfusion of steatotic livers with MTAs will lead to delipidation of hepatocytes and improved liver function in a pre-clinical model of organ salvage and rehabilitation. This work will provide foundational information to the emerging field of LD biology and is projected to demonstrate a novel cellular mechanism controlling hepatocyte LD dynamics and to identify therapeutic strategies to defat steatotic livers. The candidate is a basic scientist and transplant hepatologist, dedicated to improving the lives of patients with liver disease using a basic science approach. She is an Assistant Professor of Medicine at Mayo Clinic with a mentorship team consisting of Drs. Vijay Shah and Greg Gores. She has protected time for research and training activities, dedicated institutional funding for equipment and supplies, and a robust career development plan with specific activities and benchmarks that will position her for an independent research career. The comprehensive training plan will allow for the candidate to complete her current research plan and seek independent investigator status where she will translate these and future studies to human trials and future therapeutic interventions for patients.

项目摘要/摘要 这项研究的总体目的是针对肝细胞脂质液滴（LDS）来开发 脂肪肝病的治疗干预措施。肝脂肪变性，肝细胞LDS中的脂肪积累是关键 脂肪性肝炎的前体，可能导致肝硬化和肝细胞癌，需要肝 移植。不幸的是，肝脂肪变性还限制了可以接受移植的供体肝脏的数量 患有严重脂肪变性的供体肝脏具有高功能的高风险。因此，治疗策略 反向脂肪肝对面临脂肪性肝炎和肝硬化风险的患者很重要，并增加了 可行肝脏的供体池进行移植。我们的工作重点是肝细胞LDS，显示了三个关键 观察结果：A）Perilipin-2（PLIN2），一种与LD相关的蛋白质，可调节脂肪储存和利用，共同 与微管的本地化并共免疫沉淀； b）微管用诺科唑，钝器破坏 微管靶向剂（MTA），LD的Uncouples PLIN2促进LD融合并产生删除（即 LD含量的胞胞胞菌素分泌）的脂肪性肝细胞具有最小的细胞毒性；和c）诺科唑 促进离体肝组织的脂肪损失，对组织生存能力无效。基于这些初步数据，我们 提出了一个中心假设，即肝细胞LDS受PLIN2与 微管细胞骨架，这种相互作用是减轻脂质负担的潜在治疗靶点 脂肪肝病中的肝细胞。我们的具体目标将检验三个假设。首先，我们将测试 假设微管直接与LD相关的PLIN2相互作用。其次，我们将检验假设 微管扰动会增加脂解，并导致脂肪性肝细胞的删除。最后，我们 将检验以下假设：治疗离体脂肪酸肝组织和与脂肪变性肝脏的体内灌注 MTA将导致肝细胞的删除和改善器官临床模型中的肝功能 和康复。这项工作将为LD生物学的新兴领域提供基本信息，并且是 预计将展示一种控制肝细胞LD动力学的新型细胞机制并识别 缺乏脂肪变性肝脏的治疗策略。候选人是基础科学家和移植肝病学家， 致力于使用基础科学方法改善肝病患者的生活。她是助手 Mayo诊所的医学教授，由DRS组成的指导团队。 Vijay Shah和Greg Gores。她有 保护工作和培训活动的时间，为设备和用品提供专门的机构资金以及 一项强大的职业发展计划，具有特定的活动和基准，将她定位为 独立研究职业。全面的培训计划将允许候选人完成她 当前的研究计划并寻求独立研究者身份，她将翻译这些和未来的研究 对患者的人体试验和未来的治疗干预措施。