Expression of miR-146a in Th17 cells from rheumatoid arthritis patients and its correlation with inflammatory cytokines

To investigate the expression of miR-146a in peripheral blood T helper 17(Th17) cells of patients with rheumatoid arthritis (RA) and its correlation with inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-6(IL-6) and interleukin-17(IL-17)]. 50 patients with active RA who were treated in People's Hospital of Longhua, Shenzhen from July 2022 to June 2024 were selected, and 50 healthy people who underwent physical examination in the hospital during the same period were selected as healthy controls. Peripheral blood mononuclear cells(PBMCs) and Th cells were isolated from the venous blood of the subjects in the two groups. Quantitative real-time PCR (qPCR) was used to detect the expression of miR-146a in peripheral blood Th17 cells of the two groups, and flow cytometry (FCM) was used to detect the levels of TNF-α, IL-6 and IL-17. The peripheral blood Th17 cells of RA patients were transfected with miR-146a mimic, and the expression of miR-146a, TNF-α, IL-6 and IL-17 was detected again after transfection. Pearson correlation coefficient was used to analyze the correlation between miR-146a expression and TNF-α, IL-6, and IL-17 expression in RA patients before and after transfection. Before transfection of miR-146a mimic, the expression of miR-146a, TNF-α, IL-6, and IL-17 in peripheral blood Th17 cells of RA patients was higher than that of healthy controls(P = 0.000). After transfection, the expression level of miR-146a in peripheral blood Th17 cells of RA patients increased compared to before transfection, while the expressions of TNF-α, IL-6, and IL-17 decreased(P = 0.000). Pearson correlation analysis showed that the expression level of miR-146a in peripheral blood Th17 cells of RA patients before transfection was positively correlated with the expression levels of TNF-α, IL-6, and IL-17(r = 0.968, P = 0.000; r = 0.980, P = 0.000; r = 0.993, P = 0.000). After transfection, the expression level of miR-146a was also positively correlated with the expression levels of TNF-α, IL-6, and IL-17(r = 0.971, P = 0.000; r = 0.963, P = 0.000; r = 0.970, P = 0.000). miR-146a may participate in the pathogenesis of RA to some extent by affecting the secretion of TNF-α, IL-6, IL-17, and other related inflammatory cytokines by Th17 cells in peripheral blood of RA patients.