CircRNA102685调节miR-146影响克罗恩病肠道巨噬细胞亚群激活的研究

In the course of Crohn's disease, repeated altering of bowel inflammation activation and remission existing is related with the decreasing tolerance and aberrant activation of the immunologic effector cells in the bowel. Recent research showed that there was an increasing of CD14(hi)HLA-DR(dim) subset of intestinal macrophage in Crohn’s disease. This subset can be activated under the stimulation of bacterial lipopolysaccharide (LPS). It was known before that miR-146 could inhibit the activation of macrophage and it was found that circRNA could regulate the function of miRNA at the post-transcriptional level. In our preliminary work, we have got circRNA102685 located on chromosome 2 via circRNA chips and bioinformatics. By analysis, we speculate that there might be an axis in the intestinal macrophage as "circRNA102685↑ → decrease miR-146a/b via sponge → IRAK1↑/TRAF6↑ → NF-κB pathway activates → intestinal macrophage CD14(hi)HLA-DR(dim) subset increases and activates". The research focuses on the new aspect of circRNA regulation of the axis, to know the differentiation, activation and inhibition of intestinal macrophages. This work is in order to supply potential biological diagnostic marker and therapeutic target.

克罗恩病发病与肠道免疫效应细胞耐受性下降及异常激活增加有关。近年发现，克罗恩病患者的肠道巨噬细胞存在亚群分化、CD14(hi)HLA-DR(dim)比例增多的现象，该亚群在受到细菌脂多糖刺激时耐受性低、易被激活。以往认为miR-146对于巨噬细胞的激活存在抑制作用，近年发现环状RNA可在转录后水平调节微小RNA的功能。前期通过环状RNA芯片及生物信息学筛选获得位于2号染色体的circRNA102685，通过初步分析推测患者肠道巨噬细胞中可能存在“circRNA102685↑→海绵作用降低miR-146a/b水平→IRAK1↑/TRAF6↑→NF-κB信号通路激活→肠道巨噬细胞CD14(hi)HLA-DR(dim)亚群↑及异常激活”这一作用轴。研究通过circRNA调节干预这一作用轴的全新的角度，了解肠道巨噬细胞特定亚群分化、激活及抑制的规律，进而为克罗恩病提供潜在的生物诊断标志及治疗靶点。

环状RNA（circular RNA, circRNA）是一类可以在转录后水平调节微小RNA（microRNA, miRNA）功能的非编码RNA分子。circRNA在疾病发生发展中的作用近年来也越来越受到关注。克罗恩病（Crohn’s disease, CD）是一类自身免疫相关疾病，我们在前期工作中发现circRNA102685可能与CD疾病的活动与缓解存在一定联系，而这一关系可能通过引起肠道巨噬细胞CD14(hi)HLA-DR(dim)亚群改变而产生效应。实际研究中，通过患者活检样本及细胞实验再分析，我们发现circRNA102685对miRNA-146存在影响。患者样本的qRT-PCR验证结果提示，circRNA102685与下游信号通路相关基因IRAK1及TRAF6均存在表达上升的情况。后续的细胞实验提示circRNA102685可以在蛋白层面正向调节IRAK1和TRAF-6的表达水平。尽管circRNA102685可以在蛋白层面正向调节IRAK1和TRAF-6，但进一步针对NF-κB通路的激活情况的研究提示circRNA102685并未进一步引起NF-κB通路的激活，且对于引起肠道巨噬细胞CD14(hi)HLA-DR(dim)亚群变化的效应并不显著，据此我们推测肠道巨噬细胞的亚群变化可能是由于血液单核细胞迁移引起的。在我们的同步研究中，我们对CD患者包含肠上皮细胞的肠道活检组织也进行了circRNA芯片分析，并发现circRNA102685在部分CD患者的肠道组织中也存在表达上调的情况。研究结果提示circRNA102685可能是CD诊治中的一个潜在靶点，但相关机制仍有待进一步探寻。