Cross talk between epithelial, inflammatory and mesenchymal cells in the development of portal fibrosis

门静脉纤维化发展过程中上皮细胞、炎症细胞和间充质细胞之间的交互作用

• 批准号: 9884664
• 负责人: Mario Strazzabosco
• 金额: $ 51万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9884664
• 关键词: Acids; Address; Agonist; Anti-Inflammatory Agents; Appearance; Autosomal Recessive Polycystic Kidney; Biliary; CXCL1 gene; CXCL10 gene; CXCR3 gene; Caroli Disease; Cell membrane; Cells; Centromere; Cessation of life; Chronic; Cilia; Collagen; Cyclic AMP-Dependent Protein Kinases; Cyst; Data; Deposition; Development; Disease; Disease model; Duct (organ) structure; Epithelial; Epithelial Cells; Epithelium; Experimental Models; Fibrosis; Functional disorder; Genetic Diseases; Genetic Transcription; Genetic study; Growth; Infiltration; Inflammasome; Inflammation; Inflammatory; Inflammatory Response; Interleukin-1 beta; Kidney Diseases; Knowledge; Lead; Link; Liver; Liver Failure; Liver Fibrosis; Liver diseases; Mediator of activation protein; Mesenchymal; Mus; Mutation; Myofibroblast; NF-kappa B; Nature; Nuclear; Nuclear Translocation; PKHD1 gene; Paracrine Communication; Patients; Phenotype; Phosphorylation; Portal Hypertension; Proteins; Publishing; Role; Signal Transduction; Spleen; Therapeutic; Transforming Growth Factor beta; base; beta catenin; biliary tract; chemokine; cholangiocyte; chronic liver disease; connective tissue growth factor; fibrogenesis; interest; macrophage; mouse model; novel; novel therapeutic intervention; novel therapeutics; receptor; recruit; response; role model; therapeutic target; treatment effect; treatment strategy

There is considerable interest in understanding the mechanistic relationships between biliary damage and portal fibrosis, the main mechanism of progression in chronic cholangiopathies. Congenital Hepatic Fibrosis (CHF) and Caroli disease (CD) are genetic cholangiopathies caused by mutations in PKHD1, the gene encoding for fibrocystin, characterized by biliary dysgenesis, segmental ductal dilations and progressive portal fibrosis with portal hypertension. In CHF and CD, cholangiocyte dysfunction and portal fibrosis are caused by a genetic defect in the biliary epithelium, rather than by necroinflammatory damage and thus, represent a model disease for elucidating the role of cholangiocytes in portal fibrosis of biliary diseases. We propose to study these mechanisms in a mouse model of CHF/CD, harbouring a deleting mutation in Pkhd1 (Pkhd1del4/del4 mice). Our published and preliminary data have established that in Pkhd1del4/del4 mice biliary fibrosis develops in conjunction with accumulation of a peribiliary cell infiltrate by macrophages and by aSMA-negative, but collagen positive cells like fibrocytes. Furthermore, we have shown Pkhd1del4/del4 cholangiocytes are characterized by an increased PKA-dependent phosphorylation of β-catenin at Ser675, the nuclear translocation of pSer-675-β-catenin and its increased transcriptional activity. ß-catenin interacts with FXR inhibiting its anti-inflammatory signaling and thereby activating NF-kB and the inflammasome-dependent secretion IL-1β and consequently of CXCL1 and CXCL10, that are, in turn, able to attract macrophages. By inhibiting CXCR3, the cognate receptor of CXCL10, or by administration of an FXR agonist (obeticholic acid) macrophage infiltration was significantly reduced as well as cyst growth, spleen size and liver fibrosis. Finally, in Pkhd1del4/del4 cholangiocytes, nuclear shuttling of YAP is a pre-requisite for β-catenin activation and thus, for the expression of the pro-fibrogenic mediators CTGF, CXCL1, and CXCL10. Based on these observations, we propose that, when fibrocystin is defective, the interplay among β-catenin, YAP, FXR signalling regulates the secretion from the biliary epithelium of several chemokines that orchestrate sequential changes in the peribiliary infiltrate and are responsible for the establishment of portal inflammation and fibrosis. To demonstrate this novel hypothesis, we will investigate in specific aim 1 the relationship among YAP, β-catenin and FXR signalling in Pkhd1del4/del4 mice, their role in controlling, cyst growth, inflammation, fibrosis and their relevance as therapeutic targets. While in specific aim 2 we will investigate the nature of the pericystic infiltrate in Pkhd1del4/del4 mice, and its dynamic changes during the establishment of fibrosis and the effects of treatment strategies. These studies will provide a new model for role of cholangiocyte dysfunction in portal fibrosis. Knowledge of the regulatory signaling could lead to new therapeutic strategies.

了解胆道之间的机械关系有很大的兴趣 损伤和门户纤维化，这是慢性胆管病变进展的主要机制。 先天性肝纤维化（CHF）和Caroli病（CD）是遗传胆管病 由PKHD1突变引起的，该基因编码纤维囊蛋白，其特征是胆道 伴随门户高血压的发育不全，节段性导管扩张和进行性门纤维化。 CHF和CD，胆管细胞功能障碍和门户纤维化是由遗传缺陷引起的 胆道上皮，而不是通过坏死性损害，因此代表了一种模型疾病 阐明胆管细胞在胆道疾病的门户纤维化中的作用。我们 提议在CHF/CD的小鼠模型中研究这些机制，并具有删除突变 PKHD1（PKHD1DEL4/DEL4小鼠）。我们已发布和初步数据已经确定 PKHD1DEL4/DEL4小鼠胆道纤维化的发展与A的积累 巨噬细胞和ASMA阴性浸润，但胶原蛋白阳性浸润 像纤维细胞这样的细胞。此外，我们已显示PKHD1DEL4/DEL4胆管细胞 其特征是β-catenin在 Ser675，PSER-675-β-catenin的核易位及其转录增加 活动。 ß-catenin与FXR相互作用，抑制其抗炎信号传导和 从而激活NF-KB和炎性体依赖性分泌IL-1β，因此 CXCL1和CXCL10又可以吸引巨噬细胞。通过抑制CXCR3，同源 CXCL10的受体，或通过施用FXR激动剂（Obeticholic Acid）巨噬细胞 浸润显着降低，囊肿生长，囊尺寸和肝纤维化。 最后，在PKHD1DEL4/DEL4胆管细胞中，YAP的核穿梭是必备的先决条件 β-catenin激活，因此，用于促纤维化介质CTGF，CXCL1和 CXCL10。 基于这些观察结果，我们建议，当纤维囊蛋白有缺陷时， β-catenin，YAP，FXR信号传导调节了几个胆道上皮的分泌 趋化的趋化因子，这些因子在周围浸润中的顺序变化并负责 用于建立门户注射和纤维化。为了证明这个新的假设，我们 将在特定目标中调查YAP，β-catenin和FXR信号之间的关系 PKHD1DEL4/DEL4小鼠，它们在控制，囊肿生长，注射，纤维化和 它们作为治疗靶标的相关性。在特定目标2中，我们将调查 PKHD1DEL4/DEL4小鼠中的周细胞浸润及其在机构期间的动态变化 纤维化和治疗策略的影响。 这些研究将为胆管细胞功能障碍在门户纤维化中的作用提供新的模型。 对监管信号的了解可能会导致新的治疗策略。