Lnc-CCNE2作为ceRNA通过miR-130调控细胞自噬在结核感染中的机制研究

Studies have shown that cell autophagy plays an vital role in the regulation of mycobacterium tuberculosis (MTB) infection, and it has been reported that non-coding RNA can regulate the process of cell autophagy involving in a variety of disease process. Our group found that lnc-CCNE2 was greatly up-regulated after tuberculosis (TB) infection, which might be a target of miR-130 family. Furthermore, miR-130 decreased significantly, and Atg12 and Atg16L1, its potential target genes, increased in tuberculosis patients. According to literature reports and our previous work, we proposed that lnc-CCNE2, combining miR-130 as a competing endogenous RNA, was up-regulated in TB. This leads to the down-regulation of miR-130 and weakens the inhibition of miR-130 on the target genes of Atg12 and Atg16L1, and in turn, leads to the up-regulation of Atg12 and Atg16L1 gene and also the activated downstream pathway of cell autophagy, consequently participating in the regulation of host immune response to MTB. Combined with lncRNA, microRNA and autophagy pathway in TB for the first time, the study aimed to investigate the molecular mechanism of host regulation on TB infection from population sample, cell level and the overall level comprehensively, which would be conducive to clarify the role of non-coding RNA in the MTB pathogenesis and host tolerance, and further provide new insight into screening biomarkers for TB diagnosis and treatment.

研究发现细胞自噬在结核分枝杆菌感染的调控中扮演重要的角色，非编码RNA可调控细胞自噬过程，参与多种疾病的发生。课题组前期发现结核感染后lnc-CCNE2表达显著上调，而且其上可能存在miR-130家族的结合靶点。进一步的研究显示miR-130在结核中表达降低，其潜在靶基因Atg12和Atg16L1的表达增高。基于文献和前期研究，我们推测“结核分枝杆菌感染上调lnc-CCNE2表达，增加其与miR-130的结合，导致miR-130表达下降，从而减弱了miR-130对靶基因Atg12和Atg16L1 的抑制作用，进而激活下游细胞自噬通路，参与调控宿主对结核分枝杆菌的免疫应答过程。”本研究首次结合lncRNA、miRNA及自噬通路，从群体样本、细胞和整体水平较全面地探讨宿主对结核感染调控的分子机制，将有助于进一步阐明非编码RNA在结核感染及耐受中的作用，为寻找潜在的结核诊疗靶点提供新的方向。

最近研究表明，非编码RNA在结核分枝杆菌感染发生发展调控过程中起着重要的作用，但具体的作用靶标及机制尚未阐明。课题组一直围绕非编码RNA调控开展研究，致力于寻找结核病诊疗相关的分子靶点。本项目以非编码RNA（lncRNA、miRNA）为研究对象。首先，在结核病患者、健康对照和病例对照人群中筛选差异表达的基因位点（包括lncRNA、外泌体miRNA以及遗传易感SNP位点）作为候选分子标志物；其次，扩大样本量对有明显临床意义及差异倍数较大的基因位点进行了多阶段的群体验证，接着，采用机器学习算法联合分子标志物和电子病历构建疑难结核病的预测模型；然后，将最有潜力的位点（例如ENST00000497872）作为生物学实验的研究靶点，在BCG感染THP-1细胞模型中，采用慢病毒转染、流式细胞术、Western blot、ELISA等方法开展靶基因的功能机制学研究，探索这些靶基因的相互作用、对宿主表型的影响以及他们在结核分枝杆菌与宿主相互作用中的分子调控机制。本研究首次在中国人群中发现了一些具有潜力的结核病诊疗相关的新兴靶点，有助于进一步阐明非编码RNA在结核感染、耐受及发病中的调控作用和分子机制，同时也为合理设计和研发新的检测试剂盒和结核病诊断产品奠定一定的研究基础。