CircRNA对调节性T细胞功能的影响及其在银屑病发病中的作用

The dysfunction of regulatory T cells (Tregs) in the pathogenesis of psoriasis attracts more and more attention. Factors involved in the regulation of Tregs function are very complex, including cytokines, transcriptional factors and epigenetic mechanisms, etc. Circular RNAs (circRNA) are a special class of non-coding RNA molecules. They play important regulatory functions in post-transcriptional level, and by interacting with certain miRNAs, they are involved in the development of many diseases. By comparison the results of circRNA and mRNA microarray of psoriatic patients and healthy controls, we have identified the differentially expressed circRNAs and mRNA in psoriatic patients. The highly expressed circRNAs such as circ_0039930 and circ_0003738 can release the inhibitory functions for target genes, resulting in elevated inflammatory cytokines in Tregs in psoriasis, indicating that circRNAs are invovled in the regulation of Tregs. Based on these findings, our study is to systematically identify the differentially expressed circRNAs in psoriatic Tregs. By interfering with circRNA, we will detect their impact on the function of Tregs and to identify the target genes and related miRNA of circRNAs, and to confirm the role and the mechanism of circRNAs in the pathogenesis of dysfunctional Tregs in psoriatic patients. Implementation of our project will provide further insight into the pathogenesis of psoriasis.

调节性T细胞（Tregs）功能异常在银屑病发病中的作用日益受到重视。细胞因子、转录因子及表观遗传学等均参与Tregs功能调控。环状RNA（circRNA)是最新确认的一类非编码RNA，通过转录后水平调控miRNA，参与多种疾病的发生发展。我们通过对比银屑病和正常人Treg细胞circRNA和mRNA表达谱，发现多个异常表达的circRNA及mRNA，其中高表达的circ_0039930、circ_0003738能解除对靶基因的抑制作用，促进Tregs分泌炎症因子，提示circRNA参与调控银屑病Tregs功能。本课题拟在此基础上鉴定银屑病Tregs差异表达的circRNA，通过干预circRNA的表达，观察对Tregs功能的影响，明确circRNA结合的miRNA及作用靶基因，最终确认circRNA在银屑病Tregs功能异常中的作用及机制。项目的实施对于深入认识银屑病发病机制具有重要意义。

调节性T细胞（Treg）功能异常在银屑病发病中发挥重要作用。环状RNA（circRNA）是最新发现的一类非编码RNA，通过发挥miRNA海绵作用，解除对靶基因的抑制。我们通过对银屑病及正常人Treg细胞的circRNA表达谱芯片进行分析，筛选得到多个上调及下调表达的circRNA。进一步RT-PCR验证显示circ_0003738在银屑病Treg细胞显著高表达。在银屑病Treg细胞中转染circ_0003738的干涉慢病毒后，其对效应性T细胞的抑制功能得到显著恢复，提示银屑病Treg细胞中高表达的circ_0003738分子可能是介导其抑制功能异常的重要机制。TargetScan及miRanda软件预测发现miR-490-5p及miR-562可能为circ_0003738的靶分子，结合原位杂交实验，我们进一步验证了miR-490-5p及miR-562和circ_0003738的相互作用。为了进一步研究miR-490-5p及miR-562的靶基因，我们通过TargetScan进行预测，发现IL-17A的受体IL17RA可能是miR-562的靶分子，而IFN-γ的受体IFNGR2可能是miR-490-5p的靶分子。结合流式细胞学及RT-PCR分析，我们也发现银屑病Treg细胞中炎症因子IL-17A及IFN-γ显著高表达，提示银屑病Treg细胞中高表达的circ_0003738可能通过促进炎症因子信号通路的活化介导其抑制功能异常。进一步通过原位杂交、RT-PCR等实验，我们证实了在银屑病Treg细胞中，高表达的circ_0003738能竞争性的结合miR-562分子，解除其对靶基因IL-17RA及IL-17通路的抑制；同时，circ_0003738能竞争性的结合miR-490-5p分子，解除其对靶基因IFNGR2及IFN-γ通路的抑制，介导银屑病Treg细胞中IFN-γ及IL-17A的表达升高，抑制Treg细胞对效应性T细胞的抑制功能，促进银屑病的发病。circ_0003738分子可作为潜在的靶点为未来治疗银屑病提供新的方向。