Immune Modulation of Macrophages in Obstructive Cholestasis

项目总结： 阻塞性胆汁淤积性肝病带来很高的医疗负担，因为没有药物治疗可以预防 因此，它们仍然是肝移植的主要适应症。而最初的目标是 梗阻性胆管病是胆管疾病，免疫反应是导致持续肝损伤的主要原因。 已知巨噬细胞在淤胆性肝损伤的机制中发挥重要作用，然而，疾病- 调节性免疫疗法尚未建立，并代表着一种未得到满足的医疗需求。我们一直在 第一个对胆汁淤积症肝脏样本进行单细胞RNA测序(scRNA-seq)的公司将使用这一技术 目前研究的初步数据克服了药物治疗方面的差距。 我们已经在胆汁淤积的肝脏样本中发现了在交界处表达RORA的巨噬细胞的亚群 胆汁淤积症和正常巨噬细胞之间的假时间轨迹分析。RORA编码一种维甲酸 受体相关孤儿受体α(RoR-)促进人抗炎极化 巨噬细胞。我们的数据表明，在淤胆性肝损伤中可能出现了RORA+巨噬细胞，从而 一种新的治疗靶点。虽然RoR激动剂在小鼠模型中显示出改善肝损伤的作用 在非酒精性脂肪性肝炎中，RORA在淤胆性肝病中的作用尚未被研究。我们 假设RORA+肝巨噬细胞是修复反应所必需的 胆汁淤积性损伤；因此，RoR激动剂将通过转化促炎因子促进修复 巨噬细胞进入这一关键的促进恢复的亚群。 我们将通过以下几个方面来验证我们的假设：1)肝损伤的临床参数与 胆汁淤积性和非胆汁淤积性肝病患者RORA+肝巨噬细胞的转录寿命 利用scRNA-seq，2)鉴定胆道缓解后的修复性巨噬细胞免疫反应 使用一种创新的可逆性胆管结扎小鼠模型的梗阻，以及3)对 RoR激动型小鼠模型中的疾病表型。人和人之间的转录相关性 小鼠巨噬细胞亚群将为将当前研究结果转化为未来的研究结果提供基础 人类免疫调节治疗试验。此外，从这项提案中获得的数据将使进一步 胆汁淤积症小鼠模型中RoR激动剂的研究及命运定位实验 确定ROR反应巨噬细胞的来源(骨髓源性与组织驻留)。

PROJECT SUMMARY: Obstructive cholestatic liver diseases carry a high medical burden as there is no medical therapy to prevent disease progression and thus they remain a leading indication for liver transplantation. While the initial target in obstructive cholangiopathies is the bile duct, the immune response is the major cause for ongoing liver injury. Macrophages are known to play a significant role in the mechanism of cholestatic liver injury, however, disease- modulating immunotherapies have not been established and represent an unmet medical need. We have been the first to perform single-cell RNA sequencing (scRNA-seq) on cholestatic liver samples and will use this preliminary data in the current study to overcome the gap in medical therapy. We have identified a subset of RORA-expressing macrophages in cholestatic liver samples that is at the interface between cholestatic and normal macrophages on pseudotime trajectory analysis. RORA encodes a retinoic acid receptor-related orphan receptor alpha (ROR) that is known to promote anti-inflammatory polarization of human macrophages. Our data suggests that RORA+ macrophages may emerge in cholestatic liver injury and thus be a novel therapeutic target. While ROR-agonism has shown improvement in hepatic injury in a murine model of non-alcoholic steatohepatitis, the role of RORA in cholestatic liver disease has not been investigated. We hypothesize that RORA+ hepatic macrophages are necessary for the reparative response after cholestatic injury; thus, ROR agonism will promote repair through the conversion of pro-inflammatory macrophages into this critical pro-restorative subset. We will investigate our hypothesis through: 1) correlation between clinical parameters of liver injury and the transcriptional prolife of RORA+ hepatic macrophages in cholestatic and non-cholestatic human liver diseases using scRNA-seq, 2) identification of the reparative macrophage immune response after alleviation of biliary obstruction using an innovative murine model of reversible bile duct ligation, and 3) evaluation of changes in disease phenotype in our murine model upon ROR-agonism. Transcriptional correlation between human and murine macrophage subsets will provide the foundation to translate findings from the current study into future human immune-modulatory therapeutic trials. In addition, data obtained from this proposal will enable further studies on ROR-agonism in disease-specific murine models of cholestasis as well as fate-mapping experiments to determine the origin (bone-marrow derived versus tissue-resident) of the ROR-responsive macrophages.