Intestinal exosomes in alcohol-induced liver injury

肠道外泌体在酒精性肝损伤中的作用

基本信息

批准号：
10453769
负责人：
Je-Hyun Yoon
金额：
$ 33.64万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10453769
关键词：
AUF1A protein Acetaldehyde Alcohol-Induced Disorders Alcoholic Liver Diseases Alcoholism Alcohols Binding Binding Proteins Blood Blood Circulation CRISPR/Cas technology CYP2E1 gene Cells Chemicals Cytosol Dissociation Distant Endotoxins Enzymes Epithelial Cells Ethanol Ethanol Metabolism Extracellular Protein Family Fatty Liver Generations Genes Genetic Genetic Transcription Genetic Translation Hepatic Hepatocyte Heterogeneous-Nuclear Ribonucleoprotein K Human Individual Inflammation Inflammatory Intestinal permeability Intestines Investigation Knockout Mice Ligands Liver Liver Function Tests Liver diseases Measures Mediating Messenger RNA MicroRNAs Molecular Mus Organ Oxidative Stress Pathway interactions Penetration Phosphorylation Phosphotransferases Play Post-Translational Regulation Protein-Serine-Threonine Kinases Proteins Publishing RNA RNA-Binding Proteins RNA-targeting therapy Reactive Oxygen Species Role Serum Signal Pathway Signal Transduction Source Stream TLR7 gene Testing Tissues Transcriptional Activation Work alcohol exposure alcohol use disorder base cell growth circulating microRNA clinically relevant cohort cytokine exosome feeding in vivo inhibitor insight intestinal epithelium liver function liver inflammation liver injury mRNA Decay mouse model new therapeutic target novel therapeutics organ injury prevent receptor response senescence

项目摘要

PROJECT SUMMARY Although binge alcohol-induced liver injury has been studied extensively in the context of endotoxins and alcohol itself, it was recently revealed that circulating protein and RNA factors play an essential role as well. Ethanol- inducible cytochrome P450-2E1 (CYP2E1), a key enzyme in ethanol metabolism to generate Reactive Oxygen Species (ROS), promotes alcohol-induced hepatic steatosis and inflammatory liver disease, at least in part by mediating changes in intestinal permeability to endotoxins and release of extracellular proteins and RNAs into the blood stream. Specific miRNAs, including let-7 family miRNAs, have been shown to be amplified in serum from alcohol use disorder (AUD) cohorts having decreased liver function, suggesting that these miRNAs contribute to ethanol-induced injury of organs such as the liver. In my published studies and preliminary investigations, I made two key observations that contribute to my scientific premise that let-7b is released from the intestine through exosomes upon binge alcohol: 1) I demonstrated that the RNA-binding protein AUF1 binds mature let-7b miRNA, the ligand of Toll-like Receptor 7 (TLR7) in liver, and that this binding modulates its existence in cytosol and exosome; 2) I showed that the Serine/Threonine kinase MST1 mediates oxidative stress-induced phosphorylation of RNA-binding proteins such as AUF1 and is required for let-7b enrichment in blood exosomes after alcohol binging. This latter finding suggests that ROS-mediated signaling modulates interaction of AUF1 and miRNA through MST1-mediated phosphorylation. Based on these observations, I hypothesize that ethanol-induced activation of MST1 kinase results in the AUF1-dependent exosomal release of let-7b targeting hepatic TLR7, resulting in transcriptional activation of pro-inflammatory cytokines that cause liver injury through hepatic senescence. For this project, we will focus on elucidating the critical functions of AUF1 phosphorylation by MST1 in the dissociation of let-7b from AUF1, the release of let-7b from the intestine to the blood stream via cargo proteins QKI and hnRNP K, and subsequent hepatic injury.

项目概要尽管酗酒引起的肝损伤已在内毒素和酒精的背景下进行了广泛的研究就其本身而言，最近发现循环蛋白和 RNA 因子也发挥着重要作用。乙醇- 诱导型细胞色素 P450-2E1 (CYP2E1)，乙醇代谢中产生活性氧的关键酶物种（ROS），促进酒精诱导的肝脂肪变性和炎症性肝病，至少部分是通过介导肠道对内毒素的通透性变化以及细胞外蛋白和 RNA 的释放血流。特定 miRNA，包括 let-7 家族 miRNA，已被证明在血清中扩增来自肝功能下降的酒精使用障碍 (AUD) 人群，表明这些 miRNA 导致乙醇引起的肝脏等器官损伤。在我发表的研究和初步研究中在调查中，我做了两个关键的观察，这有助于我的科学前提：let-7b 是从酗酒后通过外泌体进入肠道：1）我证明 RNA 结合蛋白 AUF1 结合成熟的let-7b miRNA，肝脏中Toll样受体7（TLR7）的配体，并且这种结合调节其存在于细胞质和外泌体中； 2) 我证明丝氨酸/苏氨酸激酶 MST1 介导氧化应激诱导的 RNA 结合蛋白（如 AUF1）磷酸化，是 let-7b 富集所必需的酗酒后的血液外泌体。后一项发现表明 ROS 介导的信号调节 AUF1 和 miRNA 通过 MST1 介导的磷酸化相互作用。根据这些观察，我假设乙醇诱导的 MST1 激酶激活导致 AUF1 依赖性外泌体释放 let-7b 靶向肝脏 TLR7，导致促炎细胞因子转录激活，导致肝脏损伤肝脏衰老造成的损伤。对于这个项目，我们将重点阐明 AUF1 的关键功能 MST1 磷酸化导致 let-7b 从 AUF1 解离，let-7b 从肠道释放到通过货物蛋白 QKI 和 hnRNP K 的血流，以及随后的肝损伤。