Mechanisms of mast cell/cholangiocyte regulation of non-alcoholic fatty liver disease progression

非酒精性脂肪性肝病(NAFLD)是脂肪沉积到肝脏(脂肪变性)引起的结果 除了酒精之外，NAFLD现在是西方发达国家最常见的肝病 国家。如果不治疗或再次发生侮辱(“两击”假说)，NAFLD可发展为NASH。 虽然肝细胞被认为是NAFLD的主要细胞，但新的研究表明 胆管细胞和肥大细胞都有助于NAFLD的进展，并可能导致NAFLDèNASH 过渡。此外，受损的胆管细胞经历衰老，并呈现与衰老相关的 分泌表型(SASP)，这也可能有助于NASH的炎症环境。MCS 在肥胖患者的脂肪组织中发现，NAFLD患者的组胺水平增加， NASH与终末期肝病。到目前为止，还没有成功的治疗NAFLD的方法， 除了改变饮食和生活方式；而且，还没有研究来检验这种潜在的 NAFLD模型中胆管细胞与系膜细胞的旁分泌相互作用。此外，协同效应 巨噬细胞、胆管细胞、肝星状细胞和枯否细胞之间的关系尚不完全清楚 检查过了。这项研究的前提是：(I)先前的工作表明，两种胆管细胞 和MC对NAFLD的贡献；(Ii)从PI的工作证明MC对肝脏损伤有贡献，并且 疾病进展的关键调节因素；以及，(3)初步数据显示，存在直接相互作用 在胆管细胞和巨噬细胞之间影响肝损伤，库普弗细胞激活/炎症和 NAFLD期间HSC驱动的纤维化。在SA1中，PI将使用小鼠检测胆汁诱导的MC迁移 应用HFD/HFCS和Vivo-Morpholino治疗以抑制胆管衰老。这一目标将集中于 主要研究胆管细胞和巨噬细胞之间的相互作用。SA2将重点关注MC对以下方面的贡献 使用MC耗尽和重新引入MC的遗传模型进行NAFLD进展。这些研究 使我们能够检查失去MC的影响，但也可以确定MC是否使NAFLD进展和 潜在的非酒精性脂肪肝向非酒精性脂肪肝的转变(以肝脏炎症加重为标志)。最后，在SA3中，PI将 利用药物抑制直接靶向抑制MC衍生的组胺和转化生长因子-β1 这种炎性分子。初步数据和以前的出版物显示，转化生长因子-β1可能是 非酒精性脂肪肝与肝损伤(包括纤维化)的调节剂；MC衍生的组胺调节转化生长因子-β1 表达和分泌。在所有提议的目标中，PI将评估由两种西方饮食引起的NAFLD (HFD/HFCS)和蛋氨酸-胆碱缺乏(MCD)饮食。此外，代谢综合征的特点 包括胰岛素抵抗、甘油三酯升高、脂蛋白异常和糖耐量异常 已评估。靶向MC介体可能是治疗NAFLD的一种有益的治疗方法 进步。！

Non-alcoholic fatty liver disease (NAFLD) develops as a result of fat deposited into the liver (steatosis) caused by other factors aside from alcohol; and, NAFLD is now the most common liver disease in Western developed countries. If left untreated or if another insult occurs (“two-hit” hypothesis), NAFLD can develop into NASH. While hepatocytes are believed to be the primary cell involved in NAFLD, new studies have demonstrated that both cholangiocytes and mast cells (MCs) contribute to NAFLD progression and potentially to NAFLDèNASH transition. Further, damaged cholangiocytes undergo senescence and take on a senescence-associated secretory phenotype (SASP), which may also contribute to the inflammatory environment seen in NASH. MCs are found in adipose tissue of obese patients and histamine levels are increased in patients with NAFLD, NASH and end-stage liver disease. To date, no successful treatments have been developed for NAFLD, aside from altering diet and lifestyle; and, there have been no studies to examine the potential paracrine interaction between cholangiocytes and MCs in models of NAFLD. Further, the synergistic relationship between MCs, cholangiocytes, hepatic stellate cells (HSCs) and Kupffer cells has not been fully examined. The premise of the study is supported by: (i) previous work demonstrating that both cholangiocytes and MCs contribute to NAFLD; (ii) work from the PI demonstrating that MCs contribute to liver damage and are critical regulators of disease progression; and, (iii) preliminary data showing that there is a direct interaction between cholangiocytes and MCs that influences hepatic damage, Kupffer cell activation/inflammation and HSC-driven fibrosis during NAFLD. In SA1, the PI will examine biliary-induced MC migration using mice subjected to HFD/HFCS and Vivo-Morpholino treatments to inhibit biliary senescence. This aim will focus primarily on the interactions between cholangiocytes and MCs. SA2 will focus on the contribution of MCs to NAFLD progression by using a genetic model of MC depletion and also reintroduction of MCs. These studies allow us to examine the effects of losing MCs, but also to determine if MCs perpetuate NAFLD progression and potentially NAFLD to NASH transition (marked by enhanced liver inflammation). Finally, in SA3, the PI will focus on the inhibition of MC-derived histamine and TGF-b1 using pharmaceutical inhibition to directly target this inflammatory molecule. Preliminary data and previous publications reveal that TGF-b1 may be a key modulator of NAFLD and liver damage (including fibrosis); and, MC-derived histamine regulates TGF-b1 expression and secretion. In all of proposed aims, the PI will evaluate NAFLD induced by both Western Diet (HFD/HFCS) and the methionine-choline deficient (MCD) diet. In addition, features of metabolic syndrome including insulin resistance, elevated triglycerides, lipoprotein abnormalities, and glucose intolerance will be evaluated. Targeting MC mediators may be a beneficial therapeutic approach to managing NAFLD progression.!