Department of Orthopaedics, Xuzhou Central Hospital, No.199 Jiefang Road, Xuzhou 221009, China.
Department of Orthopaedics, Xuzhou Clinical School of Xuzhou Medical University, No.199 Jiefang Road, Xuzhou 221009, China.
Biosci Rep. 2018 Nov 13;38(6). doi: 10.1042/BSR20180982. Print 2018 Dec 21.
Fibroblast-like synoviocytes (FLSs) that line the intimal synovium play a crucial role in the pathogenesis of rheumatoid arthritis (RA). miR-199a-3p is a highly conserved miRNA that has been shown to regulate a variety of growth behaviors in diverse cell types. However, the role of miR-199a-3p in RA-FLS is still unknown. Here, we presented the first experimental evidence showing that miR-199a-3p was a critical regulator of RA-FLS function. miR-199a-3p expression was significantly reduced in RA-FLS compared with normal FLS. Ectopic expression of miR-199a-3p significantly inhibited RA-FLS proliferation and induced apoptosis, which was demonstrated by an increase in caspase-3 activity and Bax/Bcl-2 ratio. Our bioinformatics analysis identified Retinoblastoma 1 () gene to be a direct target of miR-199a-3p. In RA-FLS, miR-199a-3p directly targetted the 3'-UTR of mRNA and suppressed endogenous RB1 expression, whereas miR-199a-3p-resistant variant of RB1 was not affected. Silencing RB1 decreased cell proliferation and promoted apoptosis in RA-FLS, an effect comparable with miR-199a-3p overexpression. Enforced expression of RB1 partially restored cell proliferation and attenuated apoptosis in miR-199a-3p-overexpressing RA-FLSs. In summary, miR-199a-3p is down-regulated in RA-FLS, and miR-199a-3p inhibits proliferation and induces apoptosis in RA-FLS, partially via targetting RB1. The miR-199a-3p/RB1 pathway may represent a new therapeutic target for RA.
成纤维样滑膜细胞（FLS）衬里滑膜内膜，在类风湿关节炎（RA）发病机制中起着至关重要的作用。miR-199a-3p 是一种高度保守的 miRNA，已被证明可以调节多种细胞类型的各种生长行为。然而，miR-199a-3p 在 RA-FLS 中的作用尚不清楚。 在这里，我们首次提供了实验证据，表明 miR-199a-3p 是 RA-FLS 功能的关键调节因子。与正常 FLS 相比，RA-FLS 中的 miR-199a-3p 表达显著降低。miR-199a-3p 的异位表达可显著抑制 RA-FLS 的增殖并诱导凋亡，这表现为 caspase-3 活性和 Bax/Bcl-2 比值的增加。我们的生物信息学分析确定了视网膜母细胞瘤 1 () 基因是 miR-199a-3p 的直接靶标。在 RA-FLS 中，miR-199a-3p 直接靶向 3'UTR 的 mRNA 并抑制内源性 RB1 表达，而 miR-199a-3p 抗性变体的 RB1 不受影响。沉默 RB1 可降低 RA-FLS 的细胞增殖并促进凋亡，这与 miR-199a-3p 的过表达效果相当。RB1 的强制表达部分恢复了 miR-199a-3p 过表达的 RA-FLS 中的细胞增殖并减弱了凋亡。 总之，miR-199a-3p 在 RA-FLS 中下调，miR-199a-3p 通过靶向 RB1 抑制 RA-FLS 的增殖并诱导凋亡。miR-199a-3p/RB1 通路可能成为 RA 的新治疗靶点。
