MicroRNA-155 Participates in the Expression of LSD1 and Proinflammatory Cytokines in Rheumatoid Synovial Cells.

Ziliang Yu,Hao Liu,Wei Liu,Jianbo Fan,Feihu Chen

doi:10.1155/2020/4092762

Abstract

MicroRNA-155 (miRNA-155) is abundant in fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). Lysine-specific demethylase 1 (LSD1) has been found that it can ameliorate the severity of RA. Tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 are key proinflammatory cytokines implicated in the pathogenesis of RA. In our study, we investigated whether miRNA-155 participates in the expression of LSD1 and proinflammatory cytokines in rheumatoid synovial cells. First of all, flow cytometry and cell counting kit-8 analysis were employed to explore the apoptosis and proliferation of FLS, respectively. Subsequently, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to probe into the level of miRNA-155 in FLS when stimulated by miRNA-155 molecules. Moreover, RT-qPCR was used to explore the relative LSD1 miRNA expression in FLS when stimulated by miRNA-155 molecules, and Western blot and immunofluorescence assay were applied to probe into the expression level of LSD1. Finally, enzyme-linked immunosorbent assay was employed to analyze the secreting level of proinflammatory cytokines in FLS when stimulated by miRNA-155 molecules. RA-FLS showed a higher apoptosis rate than normal FLS. The cell proliferation of both HFLS and MH7A cells was promoted by miRNA-155 upregulation. Meanwhile, the expression of LSD1 and proinflammatory cytokines in the FLS of RA was also changed by miRNA-155 regulation. In conclusion, miRNA-155 participates in the expression of LSD1 and proinflammatory cytokines in rheumatoid synovial cells. These findings imply a potential function and interaction of miRNA-155 and LSD1.

Highlights

Rheumatoid arthritis (RA) is a kind of chronic autoimmune disorder featured by nonspecific inflammation of synovial membranes and joints
Earlier studies have shown that proinflammatory cytokines and inflammatory mediators are released in the pathological process of RA, which leads to chronic, symmetrical, and polysynovial arthritis
Tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and Mediators of Inflammation interleukin-6 (IL-6) are key proinflammatory cytokines implicated in the pathogenesis of RA [6, 7]

Summary

Introduction

Rheumatoid arthritis (RA) is a kind of chronic autoimmune disorder featured by nonspecific inflammation of synovial membranes and joints. Earlier studies have shown that proinflammatory cytokines and inflammatory mediators are released in the pathological process of RA, which leads to chronic, symmetrical, and polysynovial arthritis. These factors cause recurrent and progressive joint pain and swelling, which eventually develop into joint damage, rigidity, and deformity, and even involve extraarticular organs [3, 4]. The synovial fluid produced by proliferative FLS increases the release of proinflammatory cytokines, which are crucial for both the joint destruction and the spread of inflammation in RA [5]. In view of the above, we aimed at proving whether miRNA-155 can regulate the expression of LSD1 in RA and affect the secretion of proinflammatory cytokines. We used miRNA-155 mimics and inhibitor to stimulate HFLS and MH7A cells to explore the effects of miRNA-155 on cell proliferation, and the expression of LSD1 and proinflammatory cytokines

Materials and Methods

Results

Discussion