Immune Modulation of Macrophages in Obstructive Cholestasis

项目概要： 阻塞性胆汁淤积性肝病具有很高的医疗负担，因为没有药物治疗可以预防 疾病进展，因此它们仍然是肝移植的主要指征。虽然最初的目标在 梗阻性胆管病是胆管，免疫反应是持续肝损伤的主要原因。 已知巨噬细胞在胆汁淤积性肝损伤的机制中起重要作用，然而，疾病- 调节免疫疗法尚未建立，并且代表了未满足的医疗需求。我们一直 第一个对胆汁淤积性肝脏样本进行单细胞RNA测序（scRNA-seq）的公司， 目前研究中的初步数据，以克服药物治疗中的差距。 我们已经在胆汁淤积的肝脏样本中鉴定了一个表达RORA的巨噬细胞亚群， 胆汁淤积和正常巨噬细胞之间的伪时间轨迹分析。RORA编码视黄酸 受体相关孤儿受体α（ROR α），已知其促进人巨噬细胞的抗炎极化， 巨噬细胞我们的数据表明，RORA+巨噬细胞可能出现在胆汁淤积性肝损伤，因此， 一个新的治疗靶点。虽然ROR β激动剂在小鼠模型中显示出肝损伤的改善， 在非酒精性脂肪性肝炎中，RORA在胆汁淤积性肝病中的作用尚未研究。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激动剂将通过促炎性转化促进修复。 巨噬细胞转化为这个关键的促进恢复的亚群。 我们将通过以下方面来研究我们的假设：1）肝损伤的临床参数与肝损伤程度之间的相关性。 胆汁淤积性和非胆汁淤积性人类肝病中RORA+肝巨噬细胞的转录前体 使用scRNA-seq，2）鉴定在减轻胆汁性炎症后的修复性巨噬细胞免疫应答， 使用可逆性胆管结扎的创新小鼠模型进行梗阻，以及3）评价 在我们的鼠模型中，ROR β-激动后的疾病表型。人类与 小鼠巨噬细胞亚群将为将来的研究提供基础 人类免疫调节治疗试验。此外，从该提案中获得的数据将有助于进一步 在疾病特异性胆汁淤积小鼠模型中ROR β-激动作用的研究以及命运作图实验 以确定ROR β-反应性巨噬细胞的来源（骨髓来源与组织驻留）。

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.