The role of microRNA-146a in the regulation of CD4+ T lymphocytes and the pathogenesis of psoriasis vulgaris / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the effects of miRNA-146a on the differentiations and functions of CD4+ T lymphocytes in patients with psoriasis vulgaris.Metbods Thirty patients with psoriasis vulgaris and twenty heathy subjects were enrolled in this study.Quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of miRNA-146a in CD4+ T lymphocytes isolated from the peripheral blood samples.The levels of IFN-γ and IL-4 in serum samples were determined by using enzyme-linked immunosorbent assay (ELISA).Mononuclear cells were isolated from human peripheral blood samples by using Ficoll-Hypaque density-gradients centrifugation,from which the CD4+ T lymphocytes were separated by magnetic-activated cell sorting.The CD4+ T cells (2× 106/ml) were seeded in culture plates with 6 wells.The CD4+ T lymphocytes were divided into 3 groups including the control group,miRNA-146a group and miRNA-146a inhibitor group.The numbers of Th1 and Th2 cells were measured by flow cytometry analysis (FACS).The expression of IFN-γRα,T-bet and GATA-3 at mRNA and protein levels were measured by using RT-PCR and Western blot assay,respectively.The levels of IFN-γ and IL-4 in culture supernatants of CD4+ T lymphocytes were detected by using ELISA.Results In comparison with the normal control group,there were significant increases in the expression of miRNA-146a in CD4+ T lymphocytes and the level of IFN-γin serum samples from patients with psoriasis vulgaris [(2.43±0.94) vs (1.05±0.23),(27.69±7.64) ng/L vs (9.75±2.81) ng/L,all P＜0.01].A positive correlation between the expression of miRNA-146a and the level of IFN-γ in serum was observed (r=0.837,P＜0.01).Results of the in vitro culture of CD4+ T lymphocytes showed that the number of Th1 cells,the expression of T-bet at mRNA and protein levels and the level of IFN-γin culture supernatant were significantly increased,while the expression of IFN-γRα protein was decreased in the miRNA-146a group in comparison with those of the control group (all P＜0.01).No significant differences in the number of Th2 cells,the expression of GATA-3 protein,the expression of GATA-3 and IFN-γRα at mRNA level and the level of IL-4 in culture supernatants were found between the control and miRNA-146a groups (all P＞0.05).The miRNA-146a inhibitor could effectively attenuate the effects of miRNA-146a on Th1 cells.Conclusion The miRNA-146a could promote the differentiation and enhance the function of Th1 cells.It might play an important role in the pathogenesis of psoriasis vulgaris.