miR-99a对类风湿性关节炎及TH17/Treg细胞的影响

Effects of miR-99a on rheumatoid arthritis and TH17/Treg cells

目的探讨类风湿性关节炎(RA)患者外周血单个核细胞(PBMC)中miR-99a的表达与辅助性T细胞17(T helper cell 17,TH17)、调节性T细胞(regulatory cells,Treg)比率失衡的关系。方法收集于我院就诊的RA患者80例,分为活动期RA组(42例)和稳定期RA组(38例),以体检健康者42例作为健康人对照组。流式细胞术测定各组外周血PBMC中TH17、Treg细胞数;ELISA法检测各组血清IL-17、IL-6、TFN-α、IFN-γ、IL-4和IL-10的表达水平;实时荧光定量PCR(qRT-PCR)分别测定TH17和Treg细胞特异性转录因子RORγt和FoxP3 mRNA以及RA患者PBMC中miR-99a的表达水平;western blot检测各组RORγt和FoxP3蛋白的表达水平。结果与健康人对照组相比,活动期和稳定期RA患者的TH17细胞数、RORγt mRNA和蛋白质的表达水平均显著升高,Treg细胞数及FoxP3 mRNA和蛋白质的表达水平均显著降低(P均<0.01)。活动期RA患者血清IL-17、IL-6、TNF-α、IFN-γ的表达水平均显著升高,而IL-4和IL-10的表达水平均显著降低(P均<0.01)。此外,活动期RA患者TH17细胞中miR-99a的表达水平显著升高,Treg细胞中miR-99a的表达水平显著降低(P均<0.01)。Pearson相关分析结果显示,RA患者TH17细胞中miR-99a与RORγt mRNA的表达水平呈正相关(r=0.721,P<0.01),Treg细胞中miR-99a与FoxP3 mRNA的表达水平呈正相关(r=0.815,P<0.01)。结论RA患者TH17和Treg细胞中miR-99a的表达与TH17、Treg细胞发育分化关键转录因子RORγt、FoxP3密切相关,miR-99a可能通过影响RORγt和FoxP3,参与RA患者TH17/Treg细胞比率失衡。

Objective To investigate the relationship between the expression of miR-99 a in peripheral blood mononuclear cells(PBMC) and the imbalance of T helper cell 17(TH17) and regulatory T cells(Treg) in patients with rheumatoid arthritis(RA). Methods Blood samples from 80 RA patients visited our hospital, including 42 active RA patients and 38 stable RA patients, and 42 healthy controls were collected. TH17 and Treg cells in PBMC were detected by flow cytometry. The expression levels of serum IL-17, IL-6, TFN-α, IFN-γ, IL-4 and IL-10 were detected by ELISA. The expression levels of specific transcription factor RORγt of TH17, specific transcription factor FoxP3 of Treg cells and miR-99 a in PBMC of RA patients were determined by qRT-PCR. The protein levels of RORγt and FoxP3 were detected by western blot. Results Compared with healthy controls, the number of TH17 cells and the expression levels of RORγt mRNA and protein increased significantly in patients with active and stable RA, while the number of Treg cells and the expression levels of FoxP3 mRNA and protein decreased significantly(P<0.01). Compared with healthy controls and stable RA patients, the levels of serum IL-17, IL-6, IFN-γ and TFN-α increased significantly, while the levels of serum IL-4 and IL-10 decreased significantly(P<0.01). In addition, the expression levels of miR-99 a in TH17 cells of active RA patients were significantly higher than that of healthy controls and stable RA patients, while that of Treg cells significnatly lower(P<0.01). Pearson correlation analysis showed that the expression levels of miR-99 a in TH17 cells of RA patients were positively correlated with that of RORγt(r=0.721,P<0.01), and that the expression levels of miR-99 a in Treg cells were positively correlated with that of FoxP3(r=0.815,P<0.01). Conclusion The expressions of miR-99 a in TH17 and Treg cells of RA patients are closely related to the expressions of transcription factors RORγt and FoxP3 which are necessary for the development and differentiation of TH17 and Treg cells. MiR-99 a may participate in the imbalance of TH17/Treg cells in RA patients by affecting the expression of RORγt and FoxP3.