Pathogenic role of a protein complex of liver origin as regulator of a proinflammatory program that drives hepatic and intestinal injury in alcoholic liver disease

肝脏来源的蛋白质复合物作为促炎程序的调节剂的致病作用，该程序驱动酒精性肝病中的肝脏和肠道损伤

• 批准号: 10358521
• 负责人: Natalia Nieto
• 金额: --
• 依托单位: JESSE BROWN VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10358521
• 关键词: Acute Alcoholic Hepatitis; Affect; Affinity; Alcoholic Liver Diseases; Antibodies; Binding; Biological Assay; Biological Markers; CCL2 gene; CX3CL1 gene; Clinical; Clinical Trials; Complex; Complex Analysis; Data; Disease; Epithelial Cells; Ethanol; Feedback; Functional disorder; Goals; HMGB1 Protein; Hepatic; Hepatocyte; In Vitro; Inflammation; Injury; Interleukin-1 beta; Intestinal permeability; Kupffer Cells; Ligands; Liver; Measures; Molecular; Mus; Myeloid Cells; Oxides; Pathogenesis; Pathogenicity; Pathologic; Patients; Pattern; Phosphoproteins; Production; Risk; Role; Sampling; Serum; Signal Transduction; Source; Sterility; TNF gene; Testing; Therapeutic; Tight Junctions; Treatment outcome; Veterans; Work; cytokine; design; feeding; in vitro testing; in vivo; intestinal barrier; intestinal epithelium; intestinal injury; liver injury; macrophage; novel; novel therapeutics; oxidation; prevent; problem drinker; programs; protein complex; protein expression; receptor; receptor binding; receptor for advanced glycation endproducts; response

ABSTRACT Inflammation is a hallmark of alcohol-induced liver injury. Numerous studies established the role of the gut-to- liver axis, but there is limited information on how the liver-to-gut axis contributes to inflammation and injury in alcoholic liver disease. It is unknown whether ethanol-induced sterile damage-associated molecular patterns of liver origin activate a proinflammatory program that, besides being detrimental to the liver, drive intestinal barrier dysfunction, hence creating an amplifying proinflammatory feedback loop in alcoholic liver disease. Our overarching goal is to dissect the pathogenic role of a protein complex of liver origin in regulating a proinflammatory program that drives hepatic and intestinal injury in alcoholic liver disease. In prior work, we demonstrated that high-mobility group box-1 (HMGB1) is a damage-associated molecular pattern up-regulated in response to liver injury and participates in the pathogenesis of alcoholic liver disease. Interestingly, HMGB1 undergoes oxidation only in hepatocytes, and serum levels of oxidized HMGB1 ([O]HMGB1) are increased in alcoholic patients. Our preliminary data demonstrate that blocking the production of [O]HMGB1 in hepatocytes or ablating an HMGB1 receptor (the receptor for advanced glycation end- products, RAGE) in myeloid cells prevents inflammation, hepatic injury, intestinal barrier dysfunction and alcoholic liver disease. We show that Kupffer cells and infiltrated macrophages are the main hepatic source of IL1β. Importantly, we reveal that [O]HMGB1 forms a complex with IL1β. This complex binds RAGE in Kupffer cells and macrophages to produce a proinflammatory program and increases gut permeability in alcoholic liver disease. These encouraging data suggest that a proinflammatory feedback loop initiated by this complex, could exacerbate hepatic and intestinal injury in alcoholic liver disease. However, key mechanistic aspects of how this complex promotes the pathogenesis of alcoholic liver disease remain to be elucidated: 1) whether this complex is of liver origin; 2) whether it is a ligand for RAGE; 3) the signals this complex conveys in Kupffer cells and macrophages to induce a proinflammatory program that exacerbates hepatic injury; 4) whether it alters tight junction protein expression in intestinal epithelial cells and increases intestinal barrier dysfunction; and 5) whether the proinflammatory program itself also contributes to intestinal barrier dysfunction. We propose a conceptually novel framework of a liver-to-gut proinflammatory feedback loop in alcoholic liver disease. Our central hypothesis is that this complex is of liver origin and binds RAGE in Kupffer cells and macrophages to induce a proinflammatory program that exacerbates hepatic injury. By binding RAGE in intestinal epithelial cells and/or by inducing the proinflammatory program, this complex alters tight junction protein expression and increases intestinal barrier dysfunction. We will test this hypothesis by pursuing three specific aims. In Aim 1, we will identify the complex as being of liver origin. In Aim 2, we will determine the complex binding affinity for RAGE in Kupffer cells and macrophages and identify the signals through which the complex induces a proinflammatory program that exacerbates hepatic injury. In Aim 3, we will determine if the complex alters tight junction protein expression and increases intestinal barrier dysfunction by binding RAGE in intestinal epithelial cells and/or by inducing the proinflammatory program. Therefore, targeting this complex could have significant therapeutic potential.

抽象的 炎症是酒精引起的肝损伤的标志。大量研究证实了肠道对 肝轴，但关于肝肠轴如何导致炎症和损伤的信息有限 酒精性肝病。目前尚不清楚乙醇诱​​导的无菌损伤是否与 肝脏来源激活促炎程序，除了对肝脏有害之外，还会驱动肠道 屏障功能障碍，从而在酒精性肝病中形成放大的促炎反馈回路。我们的 总体目标是剖析肝脏来源的蛋白质复合物在调节 促炎症程序可导致酒精性肝病中的肝脏和肠道损伤。 在之前的工作中，我们证明了高迁移率族盒-1（HMGB1）是一种损伤相关分子 模式因肝损伤而上调，并参与酒精性肝病的发病机制。 有趣的是，HMGB1 仅在肝细胞中发生氧化，并且氧化的 HMGB1 的血清水平 ([O]HMGB1) 在酒精患者中增加。我们的初步数据表明，阻止生产 肝细胞中的 [O]HMGB1 或消除 HMGB1 受体（晚期糖基化末端受体） 产品（RAGE）在骨髓细胞中可预防炎症、肝损伤、肠道屏障功能障碍和 酒精性肝病。我们发现库普弗细胞和浸润的巨噬细胞是肝脏的主要来源 IL1β。重要的是，我们发现 [O]HMGB1 与 IL1β 形成复合物。该复合物与 Kupffer 中的 RAGE 结合 细胞和巨噬细胞产生促炎程序并增加酒精肝中的肠道通透性 疾病。 这些令人鼓舞的数据表明，由这种复合物引发的促炎症反馈循环可以 加剧酒精性肝病中的肝脏和肠道损伤。然而，关键的机制方面如何 这种复合物促进酒精性肝病的发病机制仍有待阐明：1）这是否 复合物源自肝脏； 2)是否是RAGE的配体； 3) 该复合物在 Kupffer 中传达的信号 细胞和巨噬细胞诱导促炎程序，加剧肝损伤； 4）是否 改变肠上皮细胞中紧密连接蛋白的表达并增加肠屏障功能障碍； 5）促炎程序本身是否也会导致肠道屏障功能障碍。 我们提出了酒精肝中肝到肠促炎反馈环的概念新颖的框架 疾病。我们的中心假设是，该复合物源自肝脏并与库普弗细胞中的 RAGE 结合，并且 巨噬细胞诱导促炎程序，加剧肝损伤。通过结合RAGE 肠上皮细胞和/或通过诱导促炎程序，该复合物改变紧密连接 蛋白质表达并增加肠道屏障功能障碍。我们将通过追求三个来检验这个假设 具体目标。在目标 1 中，我们将鉴定该复合物源自肝脏。在目标 2 中，我们将确定 库普弗细胞和巨噬细胞中 RAGE 的复杂结合亲和力，并识别信号 复合物诱导促炎程序，加剧肝损伤。在目标 3 中，我们将确定是否 复合物通过与 RAGE 结合改变紧密连接蛋白表达并增加肠道屏障功能障碍 肠上皮细胞和/或通过诱导促炎程序。因此，针对这个复合体 可能具有显着的治疗潜力。