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.

项目概要/摘要 本研究的总体目标是针对肝细胞脂滴 (LD) 的开发 脂肪肝疾病的治疗干预。肝脂肪变性，即肝细胞 LD 内的脂肪积累，是关键 脂肪性肝炎的前兆，可导致肝硬化和肝细胞癌，需要肝脏 移植。不幸的是，肝脂肪变性也限制了可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原发性无功能的风险很高。因此，治疗策略 逆转脂肪肝对于有脂肪性肝炎和肝硬化风险的患者非常重要，并且可以增加 用于移植的活肝脏供体库。我们在此重点关注肝细胞 LD 的工作显示了三个关键 观察结果：a) perilipin-2 (PLIN2)，一种调节脂肪储存和利用的 LD 相关蛋白，共同 与微管定位并共免疫沉淀； b) 用诺考达唑（一种钝性药物）破坏微管 微管靶向剂 (MTA) 将 PLIN2 与 LD 解偶联，促进 LD 融合并产生脱脂作用（即 脂肪变性肝细胞的 LD 内容物的胞吐分泌，具有最小的细胞毒性； c) 诺考达唑 促进离体肝组织的脂肪减少，而不影响组织活力。根据这些初步数据，我们 提出中心假设，即肝细胞 LD 受 PLIN2 和 微管细胞骨架，这种相互作用是减少脂质负担的潜在治疗靶点 脂肪肝疾病中的肝细胞。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 微管扰动增加脂肪分解并导致脂肪肝细胞脱脂。最后，我们 将检验以下假设：离体脂肪肝组织的治疗和脂肪肝的离体灌注 在器官挽救的临床前模型中，MTAs 将导致肝细胞脱脂并改善肝功能 和康复。这项工作将为 LD 生物学的新兴领域提供基础信息，并且 预计将展示一种控制肝细胞 LD 动态的新细胞机制，并确定 脂肪肝脱脂的治疗策略。候选人是一位基础科学家和移植肝病学家， 致力于利用基础科学方法改善肝病患者的生活。她是助理 梅奥诊所医学教授，其导师团队由博士组成。维杰·沙阿和格雷格·戈尔斯。她有 研究和培训活动的受保护时间、设备和用品的专门机构资金，以及 一个稳健的职业发展计划，其中包含具体的活动和基准，这将使她能够胜任 独立的研究生涯。全面的培训计划将使候选人能够完成她的任务 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 人体试验和未来对患者的治疗干预。