Mechanisms of synergistic regulation of biliary inflammation and fibrosis

胆道炎症和纤维化的协同调节机制

• 批准号: 9206411
• 负责人: Heather L Francis
• 金额: --
• 依托单位: OLIN TEAGUE VETERANS CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9206411
• 关键词: Acute; Agonist; Alcohols; Animal Model; Bile fluid; Biliary; Cell Communication; Cell Culture Techniques; Cells; Cholestasis; Chronic; Cicatrix; Coculture Techniques; Cromolyn Sodium; Data; Disease; Enzymes; Equilibrium; Event; Fibrosis; Goals; Growth; HRH2 gene; Hepatic; Hepatic Stellate Cell; Hepatitis Viruses; Histamine; Histamine H2 Receptors; Histamine Receptor; Histamine Release; Histidine Decarboxylase; Hospitalization; Human; Hyperplasia; In Vitro; Infiltration; Inflammation; Injectable; Ligation; Liver; Liver Fibrosis; Liver diseases; Mast Cell Stabilizer; Measures; Mediating; Mediator of activation protein; Medical; MicroRNAs; Mission; Modeling; Molecular; Molecular Biology Techniques; Morbidity - disease rate; Mus; Organ; Organ Transplantation; Paracrine Communication; Pathology; Pathway interactions; Patient Care; Patients; Pharmacology; Plasma; Play; Primary biliary cirrhosis; Proliferating; Pruritus; Publishing; Receptor Activation; Recruitment Activity; Regulation; Research; Risk; Rodent Model; Role; Signal Pathway; Signal Transduction; Source; System; Toxin; Transplantation; Vascular Endothelial Growth Factors; Veterans; angiogenesis; autocrine; bile duct; biliary tract; cell growth regulation; cell type; cholangiocyte; chronic liver disease; effective therapy; genetic manipulation; improved; in vivo; in vivo Model; insight; interest; intrahepatic; liver injury; mast cell; mortality; novel; novel therapeutic intervention; novel therapeutics; primary sclerosing cholangitis; programs; public health relevance; receptor; response; therapeutic development; therapy development

 DESCRIPTION (provided by applicant): Mechanisms of synergistic regulation of biliary inflammation and fibrosis Background: The risk of liver diseases due to alcohol and toxin abuse and hepatitis viruses in US Veterans is increasingly high and is one of the most common reasons for hospitalization and mortality. Chronic liver disease is characterized by damage to specific liver cellsècollagen and matrix accumulation fibrosis and eventual scarring. Cholangiocytes are the target cells in cholangiopathies such as Primary Sclerosing Cholangitis (PSC) and Primary Biliary Cirrhosis (PBC), which are characterized by the proliferation/loss of cholangiocytes leading to fibrosis. Management of cholangiopathies represents one of the major challenges for Veterans. This proposal aims to increase our understanding of factors that regulate liver fibrosis and to improve patient care leading to more effective treatments for these disorders. Histamine (HA) is secreted by many cells including mast cells (MCs), but also is synthesized by cholangiocytes. We have shown that: (i) HA stimulates biliary proliferation/loss via interaction with specific HA receptors (HRs) and (ii) the enzyme responsible for HA synthesis, histidine decarboxylase (HDC) regulates biliary growth via interaction with and modulation of miR-125b and vascular endothelial growth factor (VEGF). The rationale for our proposal is built upon previously published data showing that HA levels increase in PBC and PSC patients and increased MC infiltration positively correlates with increased fibrosis. MCs, which interact with both cholangiocytes and hepatic stellate cells (HSCs) are the main source of HA, and may contribute to conditions like pruritus. Our overall goals of this project are to demonstrate that (i) HA (via specific HR interaction) is a fibrosis-promoting agent derived from several cellular sources including cholangiocytes and MCs; (ii) HA-mediated fibrosis is driven by the miR-125b/VEGF axis and (iii) cholangiocytes, MCs and HSCs synergistically regulate fibrosis. We will utilize both in vitro and in vivo models in our proposal. All of our established animal models are relevant to the proposal and support VA-centered research by mimicking human liver fibrosis that is seen in patients with both acute and chronic liver injury. Our preliminary data demonstrates that (i) HA promotes fibrosis and (ii) inhibition of mast cell-derived HA decreases fibrosis and hepatic stellate cell activation. We propose the novel hypothesis that synergistic regulation of HA contributes to hepatic inflammation and fibrosis progression via the miR-125b/HDC/VEGF axis. We propose the following aims: Specific Aim 1: To demonstrate that HA promotes hepatic inflammation and fibrosis. We will develop this aim by treating rodent models with HA and HA receptor agonists and evaluating the progression of fibrosis. Further, in models that mimic human liver fibrosis, we will measure the effects of blocking mast cell-derived HA and the potential therapies derived from blocking HA receptor activation on fibrosis. Specific Aim 2 - To determine the cellular mechanisms and potential therapies of HA-mediated liver fibrosis, in vivo and in vitro. To achieve this, we will use pharmacological and molecular approaches to block HDC and the specific HA receptors and evaluate the signaling pathway involved in hepatic fibrosis. In vitro, we will utilize established molecular biology techniques to evaluate the pathways that regulate HA-induced fibrosis. Specific Aim 3: To determine the cell-to-cell interaction of HA-mediated hepatic fibrosis between cholangiocytes, MCs and HSCs using various in vitro and in vivo models of hepatic fibrosis. Our working hypothesis is that following liver injury, bile ducts proliferate inducing MC recruitment, leading to an increase in HA release and HSC activation. We will evaluate these events in both relevant in vivo models of fibrosis and using in vitro cell cultures to study cell-to-cell interaction directly. The information gained upo the successful completion of these studies are expected to provide important insights into the role that histamine plays during hepatic fibrosis progression, which will ultimately help in the identification of important signaling pathways that can be targeted for the development of therapeutic interventions for fibrosis treatment.

 描述（由申请人提供）： 胆道炎症和纤维化的协同调节机制背景：美国退伍军人因酗酒、滥用毒素和肝炎病毒而患肝脏疾病的风险越来越高，是住院和死亡的最常见原因之一。慢性肝病的特点是特定肝细胞胶原蛋白和基质堆积纤维化受损，并最终形成疤痕。胆管细胞是原发性硬化性胆管炎（PSC）和原发性胆汁性肝硬化（PBC）等胆管病的靶细胞，其特征是胆管细胞增殖/丢失导致纤维化。胆管病的治疗是退伍军人面临的主要挑战之一。该提案旨在增加我们对调节肝纤维化因素的了解，并改善患者护理，从而为这些疾病提供更有效的治疗。组胺 (HA) 由包括肥大细胞 (MC) 在内的许多细胞分泌，但也由胆管细胞合成。我们已经证明： (i) HA 通过与特定 HA 受体相互作用刺激胆道增殖/损失 (HRs) 和 (ii) 负责 HA 合成的酶组氨酸脱羧酶 (HDC) 通过与 miR-125b 和血管内皮生长因子 (VEGF) 相互作用并对其进行调节来调节胆汁生长。我们提议的基本原理是建立在之前发表的数据之上的，这些数据表明 PBC 和 PSC 患者中 HA 水平增加，并且 MC 浸润增加与纤维化增加呈正相关。 MC 与胆管细胞和肝星状细胞 (HSC) 相互作用，是 HA 的主要来源，可能会导致瘙痒等病症。我们该项目的总体目标是证明 (i) HA（通过特定的 HR 相互作用）是一种纤维化促进剂，源自多种细胞来源，包括胆管细胞和 MC； (ii) HA 介导的纤维化由 miR-125b/VEGF 轴驱动，(iii) 胆管细胞、MC 和 HSC 协同调节纤维化。我们将同时利用两者 我们建议中的体外和体内模型。我们建立的所有动物模型都与该提案相关，并通过模拟急性和慢性肝损伤患者中出现的人类肝纤维化来支持以 VA 为中心的研究。我们的初步数据表明，(i) HA 促进纤维化，(ii) 抑制肥大细胞来源的 HA 可减少纤维化和肝星状细胞活化。我们提出了一个新的假设，即 HA 的协同调节通过 miR-125b/HDC/VEGF 轴促进肝脏炎症和纤维化进展。我们提出以下目标： 具体目标 1：证明 HA 促进肝脏炎症和纤维化。我们将通过用HA和HA受体激动剂治疗啮齿动物模型并评估纤维化的进展来实现这一目标。此外，在模拟人类肝纤维化的模型中，我们将测量阻断肥大细胞来源的 HA 的效果以及阻断 HA 受体激活对纤维化的潜在疗法。具体目标 2 - 确定体内和体外 HA 介导的肝纤维化的细胞机制和潜在疗法。为了实现这一目标，我们将使用药理学和分子方法来阻断 HDC 和特定的 HA 受体，并评估与肝纤维化有关的信号通路。在体外，我们将利用已建立的分子生物学技术来评估调节 HA 诱导的纤维化的途径。具体目标 3：利用各种体外和体内肝纤维化模型确定胆管细胞、MC 和 HSC 之间 HA 介导的肝纤维化的细胞间相互作用。我们的工作假设是，肝损伤后，胆管增殖，诱导 MC 募集，导致 HA 释放和 HSC 激活增加。我们将在相关的体内纤维化模型中评估这些事件，并使用体外细胞培养物直接研究细胞间相互作用。这些研究成功完成后获得的信息预计将为组胺在肝纤维化进展过程中所发挥的作用提供重要的见解，这最终将有助于识别重要的信号传导途径，这些信号传导途径可作为制定纤维化治疗干预措施的目标。