C/EBPα-miR-130b-Sp-1逐级转录调控在LPS诱导胆管上皮黏蛋白MUC5AC高表达中的分子机制

Cholangitis and increased biliary epithelial expression of mucin have been identified as important factors in hepatobiliary lithogenesis. Previous studies had focused on inflammatory cytokines and signaling pathway mediated bile duct epithelialMUC5AC upregulation with LPS. At present, it has been confirmed that transcriptional regulation is crucial for the expression of MUC5AC. However, the mechanism remains unclear. Based on the previous research, the research group has proposed that LPS can regulate the transcription of MUC5AC in bile duct epithelium gradually by transcription factor C/EBPα, miR-130b and Sp-1, and finally induce the increase of MUC5AC expression. This project will use intrahepatic biliary epithelial cell line, transgenic mice with higher expression of miR-130b, C/EBPα knockout mice as the research platform, construction and transfection of different length of transcription factor promoter plasmid, using the luciferase reporter gene assay report system, with the intervention of LPS, detection the promoter binding sites the expression of C/EBPα, miR-130b, Sp-1 and MUC5AC，in order to explore the hypothesis which provides theoretical and experiment basis for the prevention, treatment and acquired new target for hepatobiliary lithiasis.

胆道感染和胆管上皮细胞粘蛋白高表达在肝胆管结石的形成过程中具有重要作用。以往研究多集中在炎症因子与信号通路介导LPS上调胆管上皮MUC5AC表达上，目前认为，转录调控在MUC5AC高表达中至关重要，但具体机制不清。课题组在前期研究工作基础上提出LPS通过转录因子C/EBPα、miR-130b及Sp-1逐级调控胆管上皮MUC5AC转录，最终诱导MUC5AC表达增加这一论题。本课题拟以肝内胆管上皮细胞系、miR-130b高表达转基因小鼠、C/EBPα条件性敲除小鼠为研究平台，构建并转染不同长度转录因子启动子质粒，利用双荧光素酶基因检测报告系统，明确相关启动子结合位点，并结合不同浓度LPS干预，检测转录因子C/EBPα、miR-130b、Sp-1及MUC5AC蛋白的表达等方法，在细胞水平及动物实验中分别进行论证，为获得新的肝胆管结石预防及治疗靶点提供理论和实验依据。

胆道感染和胆管上皮细胞粘蛋白高表达在肝胆管结石的形成过程中具有重要作用。以往研究多集中在炎症因子与信号通路介导LPS上调胆管上皮MUC5AC表达上，目前认为，转录调控在MUC5AC高表达中至关重要，但具体机制不清。课题组在前期研究工作基础上提出LPS通过转录因子C/EBPα、miR-130b及Sp-1逐级调控胆管上皮MUC5AC转录，最终诱导MUC5AC表达增加这一论题。本课题研究证实，miR130b-Sp1 转录信号传导通路对 LPS 引起的肝内胆管上 皮细胞中 MUC5AC 的过表达具有调控作用。miR130b 可抑制 Sp1 以及 MUC5AC 的 表达，而 Sp1 的表达增加可促进 MUC5AC 的过表达。通过干预 miR130b-Sp1 信号 传导通路可为肝内胆管结石的靶向治疗提供新的治疗方案。