Transcriptional and non-transcriptional functions of IRF3 in ALD

IRF3 在 ALD 中的转录和非转录功能

• 批准号: 10207370
• 负责人: LAURA E. NAGY
• 金额: $ 47.99万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-05 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10207370
• 关键词: Acceleration; Alcohol abuse; Alcohol consumption; Alcohol-Induced Disorders; Alcoholic Hepatitis; Alcoholic Liver Diseases; Anti-Inflammatory Agents; Antiviral Agents; Antiviral Response; Apoptosis; Apoptotic; BAX gene; Bax protein; Cells; Cessation of life; Chronic; Cirrhosis; Complex; DNA; Data; Development; Double-Stranded RNA; Elements; Ethanol; Exhibits; Failure; Fibrosis; Genes; Genetic Transcription; Hepatic; Hepatitis; Homeostasis; IRF3 gene; Immune; Immune response; Inflammation; Inflammatory; Innate Immune Response; Innate Immune System; Interferons; Knock-in Mouse; Ligands; Liver; Lysine; Mediating; Mitochondria; Molecular; Morbidity - disease rate; Mus; Natural Immunity; Pathogenesis; Pathology; Pathway interactions; Patients; Peripheral; Phenotype; Population; Proteins; Regulation; Reporter; Research Personnel; Resolution; Role; Signal Pathway; Signal Transduction; Stimulator of Interferon Genes; TLR4 gene; Therapeutic Intervention; Tissues; Ubiquitination; Viral Physiology; Virus Diseases; alcohol exposure; alcohol response; cellular targeting; chronic inflammatory disease; ds-DNA; experimental study; hepatocellular injury; improved; injury and repair; liver injury; macrophage; member; microbial; migration; monocyte; mortality; mouse model; novel; prevent; pro-apoptotic protein; receptor; recruit; response; therapeutic target; transcription factor

ABSTRACT Alcohol consumption is a leading cause of preventable morbidity and mortality worldwide. Chronic alcohol abuse underlies the pathogenesis of alcoholic liver disease (ALD), encompassed by a spectrum of pathologies, ranging from steatosis, to more severe forms of liver injury, including alcoholic hepatitis (AH), fibrosis, and cirrhosis. There is a growing appreciation of a dynamic and complex role of the innate immune system in the progression of ALD, as well as the resolution of hepatocellular injury and fibrosis. The controlled and appropriate resolution of inflammation is an essential feature of the innate immune response. This dynamic interplay between injury and repair is mediated, at least in part, by the tremendous plasticity of resident tissue macrophages and infiltrating monocytes as they respond to signals within their microenvironment. Signaling via IRF3 is an important element in the dynamic regulation of pro-survival vs pro-death pathways in immune cells. While several studies have implicated IRF3 in the progression of ALD, the mechanisms by which IRF3 contributes to liver injury are not well understood. Classically, IRF3 is known as a transcription factor essential for the induction of interferon- (IFN-) and antiviral genes. Recently, members of our team discovered that, in addition to its transcriptional functions, IRF3 directly triggers a pro-apoptotic pathway, termed RIG-I- like receptors (RLR)-induced IRF-3-mediated pathway of apoptosis (RIPA) via a non-transcriptional mechanism. In IRF3-mediated apoptosis, IRF3 is activated by linear ubiquitination on two lysine residues, resulting in the interaction of IRF3 with the pro-apoptotic protein Bax. The IRF3/BAX complex then translocates to the mitochondria where it triggers apoptosis. In order to study this pathway, we have generated a novel knock-in mouse that expresses an IRF3 protein that only exhibits non-transcriptional functions. Importantly, in preliminary experiments, we discovered that IRF3-mediated apoptosis of innate immune cells recruited to the liver in response to Gao-binge ethanol exposure dynamically exacerbates inflammation and contributes to murine alcoholic hepatitis (mAH). Here we propose to investigate the mechanisms by which the non-transcriptional activity of IRF3 contributes to both hepatic inflammation and fibrosis in models of mAH and fibrosis in 2 specific aims: SA1) Determine the contribution of the non-transcriptional function of IRF3 in mediating ethanol-induced liver injury in the Gao-binge model of mAH and a murine model of acceleration of fibrosis by ethanol and SA2) Investigate the mechanisms of IRF3 activation in immune cells during mAH or fibrosis. In summary, our studies will reveal novel roles for the non-transcriptional activity of IRF3 in exacerbating innate immune responses to alcohol, as well as identify potential therapeutic targets that would prevent and/or improve the resolution of inflammation and fibrosis in patients with ALD.

抽象的 饮酒是全球可预防的发病率和死亡率的主要原因。慢性酒精滥用 基于酒精性肝病（ALD）的发病机理，包括一系列病理学 从脂肪变性到更严重的肝损伤形式，包括酒精性肝炎（AH），纤维化和肝硬化。 对先天免疫系统在进展中的动态和复杂作用越来越欣赏 ALD，以及肝细胞损伤和纤维化的分辨率。受控且适当的分辨率 炎症是先天免疫反应的重要特征。受伤之间的这种动态相互作用 至少部分是由居民组织巨噬细胞的巨大可塑性和 当它们对微环境中的信号响应时，渗透单核细胞。 通过IRF3信号传导是促生存期与亲死亡途径的动态调节中的重要元素 虽然几项研究已经在ALD的发展中实施了IRF3，但该机制的机制 IRF3导致肝损伤的原因尚不清楚。从经典上讲，IRF3被称为转录因子 诱导干扰素-（IFN-）和抗病毒基因必不可少的。最近，我们团队的成员发现 除了其转录函数外，IRF3还直接触发了促凋亡途径，称为rig-ii 像受体（RLR）诱导的IRF-3介导的凋亡途径（RIPA）通过非转录 机制。在IRF3介导的凋亡中，IRF3通过在两个赖氨酸残基上的线性泛素化激活， 导致IRF3与促凋亡蛋白Bax的相互作用。然后易位的IRF3/BAX复合物 到线粒体触发凋亡的线粒体。为了研究这一途径，我们产生了一个新颖 表达仅表现出非转录功能的IRF3蛋白的敲入小鼠。 重要的是，在初步实验中，我们发现IRF3介导的先天免疫细胞凋亡 响应Gao-Binge乙醇暴露的招募到肝脏会动态加剧注射和 有助于鼠类酒精性肝炎（MAH）。在这里，我们建议研究 IRF3的非转录活性在MAH和MAH模型中有助于肝注射和纤维化 2个特定目的的纤维化：SA1）确定IRF3非转录功能的贡献 乙醇诱导的MAH的GAO-BEING模型和纤维化加速度的鼠模型在乙醇中诱导的肝损伤 乙醇和SA2）研究MAH或纤维化期间免疫细胞中IRF3激活的机制。在 总而言之，我们的研究将揭示IRF3非转录活性在加剧先天性中的新作用 对酒精的免疫反应，并确定可以预防和/或改进的潜在治疗靶标 ALD患者的炎症和纤维化的分辨率。