Wang Laifang, Zhao Qing, Wang Na, Ding Yanjie, Kong Lingli, Wang Jing
Department of Rheumatism and Immunology, Huaihe Hospital of Henan University, No. 115 Ximen Street, Kaifeng, 475000, Henan, China.
J Biol Res (Thessalon). 2021 Jan 6;28(1):1. doi: 10.1186/s40709-020-00131-4.
Circ_0000396 was found to be down-regulated in the rheumatoid arthritis (RA) patients and had a high diagnostic value. However, the function and mechanisms underlying circ_0000396 in RA progression remain unclear.
The expression of circ_0000396, microRNA (miR)-203 and HMG-box transcription factor 1 (HBP1) was detected using qRT-PCR and western blot. The proliferative and apoptotic capabilities of rheumatoid arthritis synovial fibroblasts (RASFs) were measured by colony formation, CCK-8, flow cytometry and western blot assays, respectively. The levels of interleukins (IL)-6, IL-1β, IL-8 and tumor necrosis factor-α (TNF-α) were detected using enzyme-linked immunosorbent assay (ELISA). The target correlations between miR-203 and circ_0000396 or HBP1 were validated using pull-down and dual-luciferase reporter assay.
Circ_0000396 was decreased in RA synovial tissues and RASFs, and overexpression of circ_0000396 suppressed cell proliferation, induced cell apoptosis and reduced the release of inflammatory cytokine IL-6, IL-1β, IL-8 and TNF-α in RASFs, while circ_0000396 deletion functioned oppositely. MiR-203 was confirmed to be a target of circ_0000396, and miR-203 reversed the protective effects of circ_0000396 on the dysfunction and inflammation of RASFs. HBP1 was a target of miR-203, and silencing miR-203 inhibited RASFs malignant changes by regulating HBP1. In addition, circ_0000396 could regulate HBP1 by sponging miR-203, and HBP1 decrease attenuated the effects of circ_0000396 on RASF growth and inflammation.
Circ_0000396 inhibited the growth and inflammation in RASFs by regulating miR-203/HBP1 axis, providing a potential therapeutic target for RA.
研究发现环状RNA_0000396（circ_0000396）在类风湿关节炎（RA）患者中表达下调，具有较高的诊断价值。然而，circ_0000396在RA进展中的作用及机制尚不清楚。
采用qRT-PCR和蛋白质免疫印迹法检测circ_0000396、微小RNA（miR）-203和HMG盒转录因子1（HBP1）的表达。分别通过集落形成实验、CCK-8实验、流式细胞术和蛋白质免疫印迹法检测类风湿关节炎滑膜成纤维细胞（RASFs）的增殖和凋亡能力。采用酶联免疫吸附测定（ELISA）检测白细胞介素（IL）-6、IL-1β、IL-8和肿瘤坏死因子-α（TNF-α）水平。通过下拉实验和双荧光素酶报告基因实验验证miR-203与circ_0000396或HBP1之间的靶向关系。
circ_0000396在RA滑膜组织和RASFs中表达降低，circ_0000396过表达抑制RASFs细胞增殖，诱导细胞凋亡，并减少炎症细胞因子IL-6、IL-1β、IL-8和TNF-α的释放，而circ_0000396缺失则起相反作用。miR-203被证实为circ_0000396的靶标，miR-203可逆转circ_0000396对RASFs功能障碍和炎症的保护作用。HBP1是miR-203的靶标，沉默miR-203可通过调节HBP1抑制RASFs的恶性变化。此外，circ_0000396可通过吸附miR-203来调节HBP1，HBP1表达降低减弱了circ_0000396对RASF生长和炎症的影响。
circ_0000396通过调节miR-203/HBP1轴抑制RASFs的生长和炎症，为RA提供了一个潜在的治疗靶点。
