Lnc-PPIAL4D-4作为ceRNA通过miR-499-5p调控类风湿性关节炎免疫炎性损伤的机制研究

Our group found that the Single Nucleotide Polymorphisms(SNPs) located on hsa-miR-499-5p precursors was significantly associated with the level of inflammation in RA patients. Initial functional experiment demonstrated that this miRNA may lead to excessive secretion of inflammatory cytokines and participate in the regulation of immunosuppressive injury in RA patients. Recent studies suggest that long non-coding RNAs(lncRNAs) can competitively binding to microRNA(miRNA) as the form of competing endogenous RNAs(ceRNAs) and then affect the development of disease. Lnc-PPIAL4D-4 and MED13 were found to be highly expressed in RA patients by bioinformatics and combined with lncRNA and mRNA transcripts microarray, and miR-499-5p binding targets were found on both sequences. We hypothesized that the expression of lnc-PPIAL4D-4 was up-regulated and that binding to miR-499-5p was enhanced, and the expression of miR-499-5p was down-regulated, which attenuated the inhibition of miR-499-5p on downstream target gene MED13, and promote the excessive secretion of inflammatory cytokines, and ultimately lead to immune inflammatory injury and joint damage. "Combined with lncRNA, microRNA and immune inflammatory damage through ceRNA network for the first time, the study aimed to investigate the molecular mechanism of immune inflammatory damage in RA patients from cell level and the overall level comprehensively, which would provide theoretical basis and experimental basis for the potential molecular markers of diagnosis and prognosis in RA.

课题组前期研究发现，miR-499-5p前体上的SNP位点与RA炎症水平密切相关，初步功能验证提示此miRNA可能参与调控RA免疫炎性损伤。新近研究提示lncRNA可作为ceRNA竞争性结合miRNA，影响疾病的发生发展。课题组通过生物信息学预测并结合lncRNA和mRNA芯片结果，发现Lnc-PPIAL4D-4和MED13在RA内高表达，且两者序列上均存在miR-499-5p的结合靶点。我们推测“lnc-PPIAL4D-4表达上调，与miR-499-5p的结合增强，使其表达相对下调，从而减弱了miR-499-5p对MED13的抑制作用，进而促进炎性因子过度分泌，最终导致RA免疫炎症损伤和关节破坏。”本项目首次将lncRNA、miRNA和免疫炎性损伤三者以ceRNA网络联系起来，从细胞和整体水平较全面的探讨RA免疫炎性损伤的分子机制，为RA诊断预后寻找分子标志物及临床治疗提供理论和实验依据

类风湿性关节炎是一种以多关节炎性损伤为主要表现的慢性全身炎症反应性疾病，可导致软骨和骨的损害甚至残疾。加强对类风湿性关节炎的发病机制研究以求寻找新的关键致病分子正日益引起人们的关注。MiRNA与RA的发病机制密切相关，且由于miRNA免受内源性核糖核酸酶作用而在组织、血液中稳定存在，有望成为诊断RA的生物标志物。课题组前期研究发现，miR-499-5p前体上的SNP位点与RA炎症水平密切相关，初步功能验证提示此miRNA可能参与调控RA免疫炎性损伤。新近研究提示lncRNA可作为ceRNA竞争性结合miRNA，影响疾病的发生发展。课题组通过生物信息学预测并结合lncRNA和mRNA芯片结果，发现ENST00000454129和CCR4在RA内高表达，且两者序列上均存在miR-499-5p的结合靶点。我们推测ENST00000454129表达上调，与miR-499-5p的结合增强，使其表达相对下调，从而减弱了miR-499-5p对CCR4的抑制作用，进而促进炎性因子过度分泌，最终导致RA免疫炎症损伤和关节破坏。本项目首次将lncRNA、miRNA和免疫炎性损伤三者以ceRNA网络联系起来，从细胞和整体水平较全面的探讨RA免疫炎性损伤的分子机制，为RA诊断预后寻找分子标志物及临床治疗提供理论和实验依据。