Department of Pediatric Rheumatology and Allergy, the First Affiliated Bethune Hospital, Jilin University, Changchun 130021, PR China.
Ultrasonographic Department, the China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, PR China.
Biomed Pharmacother. 2017 Dec;96:173-181. doi: 10.1016/j.biopha.2017.09.120. Epub 2017 Oct 4.
Rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) with aberrant expression of microRNA (miRNA) have been reported to be involved in the initiation, progression, and perpetuation of rheumatoid arthritis (RA). In this study, we explored the biological function and underlying mechanism of microRNA-29a (miR-29a) in cultured RA-FLS from RA patients. The expression of miR-29a in serum, synovial tissues, and FLS from RA patients and health donors was detected by real-time quantitative RT-PCR (qRT-PCR). The effects of miR-29a on cell proliferation, apoptosis, and inflammatory cytokine levels in RA-FLS were also determined using Counting Assay Kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA) respectively. Luciferase reporter assay was carried out to identify the target genes of miR-29a. We observed that expression of miR-29a was markedly downregulated in serum, synovial tissues and FLS of RA patients. miR-29a overexpression in RA-FLS significantly inhibited proliferation, promoted apoptosis, and suppressed expression of inflammatory cytokines. Signal transducer and activator of transcription 3 (STAT3) was identified to be a direct target of miR-29a in RA-FLS. miR-29a overexpression suppressed the expression of STAT3, as well as phosphorylated STAT3(p-STAT3) and its downstream targets protein (Cyclin D1 and Bcl-2). In addition, the levels of miR-29a were inversely correlated with that of STAT3 in synovial tissues. Rescue experiments showed that overexpression of STAT3 effectively reversed the effect of miR-29a on proliferation and apoptosis in RA-FLS. These data indicate that miR-29a inhibits proliferation and induces apoptosis in RA-FLS by targeting STAT3, suggesting that promoting miR-29a expression may yield therapeutic benefits in the treatment of RA.
类风湿关节炎成纤维样滑膜细胞（RA-FLS）中存在异常表达的 microRNA（miRNA），这些细胞被认为参与了类风湿关节炎（RA）的发生、发展和持续。在这项研究中，我们探讨了 microRNA-29a（miR-29a）在 RA 患者培养的 RA-FLS 中的生物学功能和潜在机制。通过实时定量 RT-PCR（qRT-PCR）检测了 miR-29a 在 RA 患者血清、滑膜组织和 FLS 中的表达。分别使用细胞计数试剂盒-8（CCK-8）、流式细胞术和酶联免疫吸附试验（ELISA）检测了 miR-29a 对 RA-FLS 细胞增殖、凋亡和炎症细胞因子水平的影响。通过荧光素酶报告基因实验鉴定了 miR-29a 的靶基因。结果发现，RA 患者血清、滑膜组织和 FLS 中的 miR-29a 表达明显下调。在 RA-FLS 中转染 miR-29a 可显著抑制细胞增殖，促进细胞凋亡，并抑制炎症细胞因子的表达。信号转导和转录激活因子 3（STAT3）被鉴定为 RA-FLS 中 miR-29a 的直接靶基因。miR-29a 过表达抑制了 STAT3 及其下游靶蛋白（Cyclin D1 和 Bcl-2）的表达，同时也抑制了磷酸化 STAT3（p-STAT3）的表达。此外，滑膜组织中 miR-29a 的水平与 STAT3 的水平呈负相关。挽救实验表明，STAT3 的过表达可有效逆转 miR-29a 对 RA-FLS 增殖和凋亡的影响。这些数据表明，miR-29a 通过靶向 STAT3 抑制 RA-FLS 的增殖并诱导其凋亡，提示促进 miR-29a 的表达可能有益于 RA 的治疗。
