Redox Regulation of O-GlcNAcylation Signaling in the Pathogenesis of Alcoholic Fatty Liver Disease

酒精性脂肪肝发病机制中 O-GlcNAc 信号转导的氧化还原调节

• 批准号: 10445852
• 负责人: Ying Chen
• 金额: $ 37.69万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10445852
• 关键词: Adaptor Signaling Protein; Alcohol consumption; Alcoholic Fatty Liver; Alcoholic Liver Diseases; Alcohols; Animal Model; Antioxidants; Autophagocytosis; Biological Markers; Biological Models; Categories; Cell model; Cells; Cellular Stress; Chronic; Clone Cells; Cytoplasmic Protein; Data; Diagnostic; Disease; Disease Management; Engineering; Enzymes; Ethanol; Ethanol Metabolism; Event; Fibrosis; Free Radicals; Functional disorder; GCLM gene; Generations; Genes; Genetic Transcription; Glutathione; Goals; Hepatic; Homeostasis; Human; Inflammation; Insulin Resistance; Knockout Mice; Link; Liver; Maintenance; Mediating; Metabolic; Mitochondrial Proteins; Modeling; Modification; Molecular; Molecular Toxicology; Mus; Nuclear Proteins; Nutrient; O-GlcNAc transferase; Oxidation-Reduction; Oxidative Stress; Pathogenesis; Pathogenicity; Pathway interactions; Phosphorylation; Play; Post-Translational Protein Processing; Preventive; Process; Proteins; Proteome; Proteomics; Public Health; Regulation; Role; Signal Pathway; Signal Transduction; Signaling Protein; Site; Stress; Sulfhydryl Compounds; Testing; Tissues; Toxicogenetics; Uridine Diphosphate N-Acetylglucosamine; Yang; alcohol exposure; alcohol response; base; biological adaptation to stress; calmodulin-dependent protein kinase II; chronic liver disease; cytotoxicity; disability-adjusted life years; economic impact; endoplasmic reticulum stress; fatty liver disease; feeding; health economics; in vivo; liver metabolism; metabolomics; mortality; mouse model; multiple omics; nanobodies; novel; peptide O-linked N-acetylglucosamine-beta-N-acetylglucosaminidase; protein function; protein profiling; protein protein interaction; response; therapeutic target; transcription factor

PROJECT SUMMARY Alcoholic fatty liver disease (AFLD) is a major cause of chronic liver disease. Globally, AFLD accounts for 0.9% of total mortality and 0.6% of disability-adjusted life years and remains a public health problem worldwide. Despite its profound health and economic impact, the AFLD management remains challenging due to the lack of detailed understanding of determinants of its pathogenesis and progression. The goal of this project is to elucidate a novel role of redox-modulated hepatic O-GlcNAc signaling in alcohol-induced liver injury, and thereby identify potential novel preventive, diagnostic and/or therapeutic targets against AFLD. Oxidative stress is implicated to play a central role in many pathways involved in the initiation and progression of AFLD. Hepatic glutathione (GSH) functions in maintaining cellular redox homeostasis. Intriguingly, chronic GSH deficiency in mice harboring a global disruption of the glutamate-cysteine ligase modifier subunit (Gclm) gene confers protection against alcohol-induced steatosis. Molecular and metabolomics studies indicate that the hepatoprotective effect of low GSH is linked to activations of AMPK signaling pathway and NRF2 antioxidant response, and reprogramming of hepatic metabolism that benefits the maintenance of cellular redox and metabolic homeostasis. Multiomics analyses imply that post-transcriptional mechanisms play a significant role in mediating low GSH-elicited metabolic adaptation upon ethanol exposure. O-GlcNAcylation of protein is a prevalent form of post-translational modification (PTM), where a single O-linked N-acetylglucosamine (O- GlcNAc) moiety is added to nuclear, cytoplasmic and mitochondrial proteins. This process is controlled by a pair of O-GlcNAc cycling enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). In the liver, O- GlcNAc signaling has been shown to serve as an important mechanism for nutrient and stress sensing and subsequent regulation of liver cellular homeostasis. Aberrant O-GlcNAcylation has been implicated in hepatic insulin resistance, fatty liver disease and associated fibrosis. To date, little is known about the role of O- GlcNAcylation in AFLD pathogenesis. Our preliminary studies show that, in GSH-deficient Gclm-null mouse livers, chronic-binge ethanol feeding induced beneficial changes in global O-GlcNAylation and associated cellular pathways and signaling proteins. This project will expand upon these provocative findings and test the hypothesis predicting that adaptive O-GlcNAc signaling driven by chronic oxidative stress (due to GSH deficiency) in the liver protects against alcohol-induced liver injury. We propose to (1) utilize the Gclm-null mouse model to examine ethanol-induced changes in O-GlcNAcylation and phosphorylation modifications of the liver proteome and substrate targeting of O-GlcNAc cycling enzymes, and (2) evaluate the functional impacts of top candidate protein-O-GlcNAcylations in ethanol-associated stress response in human HepaRG cells. The proposed study will be the first examination of in vivo interplay between hepatic redox status and O- GlcNAcylation signaling in the context of alcohol induced liver injury.

项目概要 酒精性脂肪肝病（AFLD）是慢性肝病的主要原因。全球范围内，AFLD 占比 0.9% 总死亡率和伤残调整生命年的 0.6%，仍然是世界范围内的公共卫生问题。 尽管 AFLD 对健康和经济产生了深远的影响，但由于缺乏 详细了解其发病机制和进展的决定因素。该项目的目标是 阐明氧化还原调节的肝脏 O-GlcNAc 信号在酒精性肝损伤中的新作用，以及 从而确定针对 AFLD 的潜在新预防、诊断和/或治疗靶点。氧化性 应激在 AFLD 发生和进展的许多途径中发挥着核心作用。 肝脏谷胱甘肽 (GSH) 的作用是维持细胞氧化还原稳态。有趣的是，慢性 GSH 谷氨酸半胱氨酸连接酶修饰亚基 (Gclm) 基因全面破坏的小鼠缺乏 提供针对酒精引起的脂肪变性的保护。分子和代谢组学研究表明 低 GSH 的保肝作用与 AMPK 信号通路和 NRF2 抗氧化剂的激活有关 反应和肝脏代谢重新编程，有利于维持细胞氧化还原和 代谢稳态。多组学分析表明转录后机制发挥着重要作用 介导乙醇暴露后低谷胱甘肽引起的代谢适应。蛋白质的 O-GlcNAc 酰化是 翻译后修饰 (PTM) 的普遍形式，其中单个 O-连接的 N-乙酰氨基葡萄糖 (O- GlcNAc) 部分被添加到核蛋白、细胞质蛋白和线粒体蛋白中。这个过程是由一个控制 一对 O-GlcNAc 循环酶，O-GlcNAc 转移酶 (OGT) 和 O-GlcNAcase (OGA)。在肝脏中，O- GlcNAc 信号传导已被证明是营养和压力传感的重要机制， 随后调节肝细胞稳态。异常的 O-GlcNAc 酰化与肝损伤有关 胰岛素抵抗、脂肪肝疾病和相关纤维化。迄今为止，人们对O-的作用知之甚少。 AFLD 发病机制中的糖基化。我们的初步研究表明，在 GSH 缺陷的 Gclm-null 小鼠中 肝脏，长期暴食乙醇引起了整体 O-GlcNAylation 和相关的有益变化 细胞通路和信号蛋白。该项目将扩展这些具有争议性的发现并测试 假设预测适应性 O-GlcNAc 信号由慢性氧化应激驱动（由于 GSH 缺乏）在肝脏中可以防止酒精引起的肝损伤。我们建议 (1) 利用 Gclm-null 小鼠模型，用于检查乙醇诱导的 O-GlcNAcNA 酰化和磷酸化修饰的变化 O-GlcNAc 循环酶的肝脏蛋白质组和底物靶向，以及 (2) 评估功能 最佳候选蛋白-O-GlcNAc 酰基化对人类 HepaRG 乙醇相关应激反应的影响 细胞。拟议的研究将是首次检查肝脏氧化还原状态和 O- 之间的体内相互作用。 酒精引起的肝损伤中的 GlcNAc 酰化信号传导。