Downregulation of Rab3D: Critical Role in Golgi Disorganization and the Pathogenesis of Alcoholic Liver Disease

Rab3D 下调：在高尔基体紊乱和酒精性肝病发病机制中的关键作用

• 批准号: 10455408
• 负责人: Carol A. Casey
• 金额: --
• 依托单位: OMAHA VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10455408
• 关键词: Admission activity; Affect; Alcohol abuse; Alcoholic Hepatitis; Alcoholic Liver Cirrhosis; Alcoholic Liver Diseases; Alcoholic liver damage; Alcohols; Animal Model; Autophagocytosis; Autophagosome; Biochemical; Biology; Cell surface; Cells; Chronic; Cirrhosis; Coat Protein Complex I; Country; Cultured Cells; Data; Defect; Destinations; Development; Disease Progression; Down-Regulation; Endocytosis; Ethanol; Exocytosis; Face; Family; Fatty acid glycerol esters; Foundations; Functional disorder; General Population; Glutaminase; Goals; Golgi Apparatus; Guanosine Triphosphate Phosphohydrolases; Healthcare; Heavy Drinking; Hepatocyte; Hepatomegaly; Hepatotoxicity; Hypertrophy; Impairment; In Vitro; Incidence; Injury; Investigation; Knockout Mice; Laboratories; Lead; Link; Liver; Mediating; Medical; Medical center; Membrane; Military Personnel; Monomeric GTP-Binding Proteins; Morphology; Motor; Nonmuscle Myosin Type IIA; Nonmuscle Myosin Type IIB; Organ; Organelles; Pancreas; Pathogenesis; Pathway interactions; Patients; Pharmacology; Physiological; Play; Prevalence; Principal Investigator; Process; Protein Isoforms; Protein Secretion; Proteins; Recovery; Recycling; Research Personnel; Role; Severities; Small Interfering RNA; Structure; Therapeutic; Toxic effect; Vacuole; Vesicle; Veterans; Work; alcohol effect; alcohol exposure; base; experience; human subject; improved; in vivo; innovation; insight; knock-down; knockout gene; lipid metabolism; lipid transport; liver injury; military veteran; mouse model; non-muscle myosin; novel; novel strategies; novel therapeutic intervention; protein metabolism; protein transport; receptor; reconstitution; restoration; success; therapeutic development; therapeutic target; trafficking

The goal of this VA Merit is to examine how ethanol exposure results in impaired function of the Golgi apparatus. The Golgi apparatus (also called the Golgi body or Golgi complex) packages proteins into membrane bound vesicles inside the cell before the vesicles are sent to their destination. As such, this organelle resides at the intersection of the secretory, lysosomal, and endocytic pathways; it is known to be of particular importance in processing proteins for secretion. Previous work from our laboratory has identified multiple defects in endocytosis, protein trafficking, and secretion, after alcohol administration, but we have not until now, examined a role for altered Golgi function in these processes. Because the incidence of alcoholic liver disease (ALD) is greater in the Veteran population and more than half of all medical admissions in VA Medical Centers across the country are linked to alcohol abuse, we are focusing efforts towards the identification of potential targets to intervene during the progressive injury which occurs after chronic alcohol administration, and perhaps the Golgi will prove to be such a target. Of central importance to our study is the role of a small GTPase, Rab3D, which is involved in exocytosis, secretion and vesicle trafficking. We have shown that Rab3D protein content was significantly decreased after alcohol administration, and recently we have obtained exciting new preliminary data that ethanol-impaired Rab3D function plays an important role in Golgi disorganization and fragmentation. The studies proposed in this application will extend our ongoing investigation of how ethanol alters hepatocyte biology, specifically in protein processing, to an examination of its role in transport through the Golgi. We provide a concept as to how alcohol-induced remodeling of Golgi morphology is a significant impairment of post-Golgi trafficking, and this leads to utilization of trans-Golgi membranes for the formation of autophagosomes. These recent and novel findings provide an excellent foundation for this proposal and support our central hypothesis that EtOH-induced down-regulation of Rab3D disrupts the assembly and function of Golgi apparatus leading to impaired protein trafficking and metabolism, contributing to liver injury. To examine this hypothesis, we have proposed three specific aims; in Aim 1 we will determine how the function of Rab3D regulates the integrity of the Golgi, in Aim 2 we will examine how autophagy is linked to EtOH-induced Golgi disorganization, and in Aim 3 we will explore recent preliminary data examining recovery of compact Golgi and reconstitution of trans-Golgi membranes. Altogether, successful completion of these aims will characterize the effect of EtOH on Golgi disorganization, and establish a role for altered Rab3D during this process. We will be able to correlate mechanisms of alcohol-mediated liver cell trafficking impairments with impaired Golgi function and provide key information that could lead to therapeutic strategies aimed at reducing or eliminating liver injury. Dr. Casey is the principal investigator, and she is joined by three outstanding co-investigators (Drs. Petrosyan, Thomes and Rasineni). The investigators have complementary strengths which are essential for the success of the project. All four are experienced with alcoholic liver injury, and Dr. Casey has specific expertise in protein trafficking and endocytosis, while Dr. Rasineni is currently examining Rab3D function in another organ, the pancreas. Dr. Petrosyan is an expert in Golgi morphology, and Dr. Thomes brings years of experience in autophagy for the project. Together with this expertise and our exciting and innovative approach, we anticipate that we will be successful in these studies and will be able to contribute to improved healthcare for Veteran patients by the identification of mechanisms involved in the alcoholic liver injury.

这项VA Merit的目标是研究酒精暴露如何导致高尔基体功能受损。 高尔基体(也称为高尔基体或高尔基复合体)将蛋白质包裹到膜上。 在囊泡被送到它们的目的地之前，囊泡在细胞内。因此，这个细胞器驻留在 分泌途径、溶酶体途径和内吞途径的交集；已知它在 加工蛋白质以供分泌。我们实验室以前的工作已经发现了多个缺陷 酒精摄入后的内吞、蛋白质运输和分泌，但我们到目前为止还没有检查 高尔基体功能改变在这些过程中的作用。因为酒精性肝病的发病率是 退伍军人人数更多，退伍军人医疗中心超过一半的医疗入院人数 国家与酗酒有关，我们正集中努力确定潜在目标，以 对慢性饮酒后发生的进行性损伤进行干预，也许还有高尔基体 将被证明是这样的一个目标。对我们的研究至关重要的是一个小的GTP酶Rab3D的作用，它 参与胞吐、分泌和囊泡运输。我们已经证明了Rab3D蛋白质含量是 在饮酒后显著减少，最近我们获得了令人兴奋的新的初步数据 乙醇损伤的Rab3D功能在高尔基体的解体和碎裂中起着重要作用。这个 这项申请中提出的研究将扩展我们正在进行的乙醇如何改变肝细胞的研究 生物学，特别是在蛋白质加工方面，以检查其在通过高尔基体运输中的作用。我们提供 酒精诱导的高尔基体形态重塑是高尔基体后损伤的一个概念 贩运，这导致利用跨高尔基膜形成自噬小体。这些 最新的新发现为这一提议提供了良好的基础，并支持我们的中心假设 乙醇诱导的Rab3D下调扰乱高尔基体的组装和功能 蛋白质运输和新陈代谢受损，导致肝脏损伤。为了检验这一假设，我们有 提出了三个具体目标；在目标1中，我们将确定Rab3D的功能如何调节 高尔基，在目标2中，我们将研究自噬是如何与乙醇诱导的高尔基体破坏联系在一起的，在目标3中 我们将探索检验致密高尔基体恢复和跨高尔基体重建的最新初步数据 膜。总之，这些目标的成功完成将是Etoh对高尔基的影响的特征 解除组织，并在此过程中为更改的Rab3D建立一个角色。我们将能够关联到 酒精介导的肝细胞转运受损与高尔基体功能受损的机制及关键 可能导致旨在减少或消除肝脏损伤的治疗策略的信息。凯西医生是 首席调查员，与她一起的还有三名杰出的合作调查员(彼得罗相博士、托梅斯博士和 拉西内尼)。调查人员具有互补的优势，这些优势对项目的成功至关重要。 这四人都有酒精性肝损伤的经验，凯西博士在蛋白质运输和 Rasineni博士目前正在研究另一个器官--胰腺的Rab3D功能。Dr。 彼得罗相是高尔基体学方面的专家，而托姆斯博士在自噬方面为 项目。加上这种专业知识和我们令人兴奋和创新的方法，我们预计我们将成为 在这些研究中取得成功，并将能够为改善退伍军人患者的医疗保健做出贡献 探讨酒精性肝损伤的发病机制。