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.

中文翻译：

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MicroRNA-155 参与类风湿滑膜细胞中 LSD1 和促炎细胞因子的表达。

MicroRNA-155 (miRNA-155) 在类风湿性关节炎 (RA) 的成纤维细胞样滑膜细胞 (FLS) 中含量丰富。已发现赖氨酸特异性去甲基化酶 1 (LSD1) 可以减轻 RA 的严重程度。肿瘤坏死因子-α、白细胞介素 1 β 和白细胞介素 6 是与 RA 发病机制有关的关键促炎细胞因子。在我们的研究中，我们调查了 miRNA-155 是否参与了类风湿滑膜细胞中 LSD1 和促炎细胞因子的表达。首先，分别采用流式细胞术和细胞计数kit-8分析法探讨FLS的凋亡和增殖。随后，应用逆转录-定量聚合酶链反应 (RT-qPCR) 来探测受 miRNA-155 分子刺激时 FLS 中 miRNA-155 的水平。而且，RT-qPCR用于探索受miRNA-155分子刺激时FLS中LSD1 miRNA的相对表达，并应用Western印迹和免疫荧光法探测LSD1的表达水平。最后，采用酶联免疫吸附试验来分析受 miRNA-155 分子刺激时 FLS 中促炎细胞因子的分泌水平。RA-FLS 显示出比正常 FLS 更高的细胞凋亡率。miRNA-155 上调促进了 HFLS 和 MH7A 细胞的细胞增殖。同时，miRNA-155调节也改变了RA FLS中LSD1和促炎细胞因子的表达。总之，miRNA-155参与了类风湿滑膜细胞中LSD1和促炎细胞因子的表达。这些发现暗示了 miRNA-155 和 LSD1 的潜在功能和相互作用。