SAT0022 Mir-15a/16 suppress inflammatory response and cell invasion and migration in fibroblast-like synoviocytes in rheumatoid arthritis via targeting sox5. (12th June 2018)

• Record Type: Journal Article
• Authors: Tan, W.; WU, Q.; Luo, A.; Wei, Y.; Wang, F.; Zhang, M.
• Is Part Of: Annals of the rheumatic diseases. Volume 77(2018)Supplement 2
• Page Start: 878
• Page End: 878
• Publication Date: 2018-06-12
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2018-eular.4151
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Aberrant expressions of miRNAs play a critical role in the inflammatory and immune response in rheumatoid arthritis (RA). The microRNA cluster which encodes for miR-15a and miR-16, located at 13q14.3. Both these microRNAs have been implicated in the pathogenesis of many diseases, but little is known of their role in RA. Objectives: In this study, we aim to investigate the underlying molecular mechanisms of MiR-15a/16 in RA, which will provide new insight into understanding the pathogenesis of RA and identifying novel therapeutics targets for this disease. Methods: The expression of MiR-15a/16 in the peripheral blood mononuclear cell (PBMC) and synovium from RA, osteoarthritis (OA) and healthy controls (HC) was determined by RT-qPCR and Western blotting. Mimics of MiR-15a/16 were transfected into the human rheumatoid fibroblast-like synoviocytes (FLS) MH7A cell line. The effect of MiR-15a/16 on proinflammatory cytokines expression, migration and invasion of FLS was detected by RT-qPCR, transwell and F-actin staining. The potentially target gene of miR-15a/16 was predicted by bioinformatics analysis. The 3′UTR of Sox5 containing wild-type or mutated miR-15a/16 binding sites was cloned to the downstream of a luciferase vector and transfected into MH7A, respectively. Results: There is no significant difference of MiR-15a/16 expression in PBMC in RA and HC at baseline. However, the MiR-15a/16 expression is lower in PBMC from non-responders (defined DAS28 changes<1.2 after 3 months DMARDs therapy) than those in responders after 3 months DMARDs therapy. The levels of MiR-15a/16 expression were significant decreased in the synovium from RA patients, as compared with OA patients. Transfection of MH7A with MiR-15a and 16 mimic suppressed IL-1b, TNFa, IL-17 expression, decreased cell migration and invasion and affected the cytoskeletal reorganisation in RA-FLS. We co-transfected MH7A with luciferase-reporter constructs with either wild-type or mutated miR-132 or miR-15a/16 mimics. Luciferase assay showed that either miR-15a or 16 reduced the luciferase intensity of Sox5 3′UTR. However, mutated miR-15a/16 alleviated the inhibitory effect of miR-15a/16 on the intensity of Sox5 3′UTR. To determine whether Sox5 mediates the roles of miR-15a/16 in cell migration and invasion, we constructed recombinant Adenovirus SOX5 recombinant Adenovirus SOX5 overexpressing vector. We then found that overexpression of Sox5 restored the cell invasion, and migration in MH7A that were inhibited by and miR-15a/16. Conclusions: In conclusion, our data indicate that MiR-15a/16 play an important role in inflammatory response and cell invasion and migration in RA-FLS by directly targeting Sox5, and imply that these miRNAs have potential as therapeutic targets for RA. Disclosure of Interest: None declared