环状RNA调控干扰素-γ基因甲基化参与胆道闭锁发病的分子机制

Biliary atresia is a cholestatic disease that seriously threatens the health of children and is also the leading cause of liver transplantation in children, of which the pathogenesis is unknown. Circular RNA is an important non-coding RNA involved in the regulation of life activities and regulates the level of microRNA sponge after transcription and transcription. Our team has identified the expression of circular RNA and microRNA in biliary atresia by transcriptome sequencing and found that the expression of circular RNA-0011224, microRNA-29a-3p and microRNA-222-3p were significantly abnormal. Thus we predicted that there may be a mechanism of "low expression of circular RNA - microRNA sponge-low hypomethylated in the IFN-γ promoter region-high expression of IFN-γ " in the incidence of biliary atresia. This study will start from the following three aspects: ① To further study the role of circular RNA-0011224 in the development of biliary atresia in human and animal models; ②Using cellular and animal models to identify circular RNA-0011224 associated methylation control of related microRNAs and possible interacting proteins; (3) Analyzing the signaling pathways involved in regulation and revealing the epigenetic mechanisms by which circular RNAs regulate biliary atresia. Hope that this project could provide a new molecular basis for the etiology analysis, diagnosis and treatment for biliary atresia.

胆道闭锁是严重威胁儿童健康的胆汁淤积性疾病，亦是儿童肝移植的首因，发病机制不明。环状RNA是参与生命活动调控的重要非编码RNA，可调控微小RNA在转录及转录后的水平。本项目组通过转录组测序鉴定了胆道闭锁的环状RNA和微小RNA表达谱，发现环状RNA-0011224、微小RNA-29a-3p、微小RNA-222-3p表达显著异常，预测胆道闭锁发病中可能存在“环状RNA低表达—微小RNA海绵吸附—IFN-γ启动子区低甲基化—IFN-γ高表达”这一机制。本课题将从以下三方面入手：①在人体和动物模型，进一步研究环状RNA-0011224在胆道闭锁发生发展中的功能；②利用细胞、动物模型鉴定环状RNA-0011224关联的甲基化调控相关微小RNA及可能的互作蛋白；③分析其参与调控的信号通路，并初步揭示环状RNA调控胆道闭锁发生的表观遗传学机制。希望通过本项目为胆道闭锁的病因分析及诊疗提供新的分子依据。

胆道闭锁（biliary atresia，BA）是严重威胁儿童健康的胆汁淤积性疾病，亦是儿童肝移植的首因，发病机制不明，既往文献报道免疫紊乱、上皮细胞氧化损伤、胆管WNT信号通路活化在其中发挥关键作用。circRNA是参与生命活动调控的重要非编码RNA，通过miRNA海绵机制在基因转录及转录后发挥表观调控作用。本项目组通过circRNA测序及分子机制实验，发现circRNA-0011224↓-miRNA-29b↑- DNMTs↓-IFN-γ↑通路调控IFN-γ诱发BA免疫紊乱；circRNA-0008725↑-miR-122-5p↓-IFNGR2↑通路调控IFN-γ受体IFNGR2表达同样起到重要的免疫调控作用；circRNA-0004629↓-miR-127-3p↑-MCC↓通路抑制WNT信号通路抑制剂MCC表达，可能加重BA胆管损伤；circRNA-0087009↓-miR-342-3p↑-GNE↓通路抑制抗氧化蛋白MCC可能加重上皮细胞的氧化损伤。本项目从免疫紊乱、氧化应激、WNT信号通路多角度阐释了circRNA在其中的作用及潜在机制，为缓解BA肝脏炎症、肝损伤提供了新的靶向调控思路。此外，由于circRNA为共价闭合的的单链环状RNA分子，较线性RNA分子稳定，因此本项目鉴定的4种circRNA有可能为BA潜在药物靶标和生物标记物。