GSE159618
miR-497 Reduction and the Increase of its Family Member miR-424 Leads to the Dysregulation of Multiple Inflammation Related Gene in Synovial Fibroblasts with Rheumatoid Arthritis
Objectives: Mounting evidence has demonstrated that microRNAs (miRNAs) participate in rheumatoid arthritis (RA). The role of highly conserved miR-15/107 family in RA was not clarified yet, and hence investigated in this study. Methods: Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the expression of miRNAs and genes. Cell counting kit 8 (CCK-8) and FACS were used to detect proliferation and apoptosis. Protein expression was detected by using Western blotting. mRNA deep sequencing and cytokine antibody array were used to analyze differentially expressed genes, signaling pathways and cytokines. Results: In RA patients, the expression of miR-15a, miR-103, miR-497 and miR-646 was increased, while miR-424 was decreased. miR-424 and miR-497 were further investigated and the results showed that they could regulate multiple genes in rheumatoid arthritis synovial fibroblast (RASF) and affect signaling pathways. At the protein level, miR-497 mimic has an effect on all the selected inflammation related genes while miR-424 inhibitor only affects part of genes. miR-497 mimic has obvious effects on proliferation and apoptosis of RASF rather than miR-424 inhibitor. DICER1 was found to positively regulate miR-424 and miR-497, while DICER1 was also negatively regulated by miR-424. The increase of miR-424 could reduce miR-497 expression, thus forming a loop, which helps explain the dysregulated miR-424 and miR-497 condition in RA. Conclusion: Our study clarified the effects of miR-15/107 family members miR-424 and miR-497 on cell proliferation and apoptosis in RA and proposed miR-424-DICER1-miR-497 feedback loop which provided novel ideas and new inspiration for miRNA research and RA therapy. Overall design: Examine differentially expressed genes after transfection of miRNA mimics in synovial fibroblasts