Silencing Long Non-Coding RNA NEAT1 Attenuates Rheumatoid Arthritis Through Downregulation of microRNA-129 and microRNA-204 via the AMPK Signaling Pathway

Abstract

Background: The participation of long noncoding RNAs (lncRNAs) and microRNAs (miRs) in the progression of rheumatoid arthritis (RA) continues to be a topical subject of investigation. The aim of the current study was to discuss the action of lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) in fibroblast-like synoviocyte (FLS) proliferation and synovitis in RA. Methods: A rat model of RA was established. The expression of NEAT1 in the synovial tissues of RA patients and FLSs from the RA rat model was detected by RT-qPCR. Then, dual luciferase reporter assay was done to investigate the relationship among miR-129/204 and MAPK. The binding relationship between miR-204 and lncRNA NEAT1 was evaluated by RIP assay, and miR-129 promotor methylation was determined by MSP. The expression of lncRNA NEAT1, miR-129 or miR-204 were altered in FLSs, and the extent of ERK1/2 phosphorylation was detected. Besides, FLS synovitis and proliferation were detected by ELISA and EdU assay, respectively. LncRNA NEAT1 was silenced and miR-129/miR-204 was overexpressed in RA rats to explore their roles in vivo. Results: LncRNA NEAT1 was upregulated and miR-129 and miR-204 was poorly expressed in RA synovial tissues and FLSs. MAPK1 was a target gene of both miR-129 and miR-204. LncRNA NEAT1 bound to miR-204 and promoted miR-129 promoter methylation. Silencing lncRNA NEAT1 or overexpressing miR-129/miR-204 enhanced miR-129/miR204 expression, but reduced extent of ERK1/2 phosphorylation, proliferation of FLSs and synovitis in RA. Conclusion: Collectively, silencing lncRNA NEAT1 upregulated miR-129 and miR-204 to inhibit MAPK signaling pathway so as to reduce FLS synovitis in RA. Funding Statement: This study was supported by Youth Innovation in Medical Research in Sichuan Province; Health Department of Sichuan Province and Education Department of Sichuan Province (No. 18ZB0640). Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: All patients in this study signed informed consent. The experiment was officially recognized by the Ethics Committee of The Affiliated Hospital of Southwest Medical University, strictly in line with the Declaration of Helsinki. All animal measures were under the direction of experimental animals announced by the Ministry of Science and Technology of the People's Republic of China. This study minimized the pain of experimental animals as much as possible.