Modulation of microRNA-155 on CD4 + T lymphocyte in patients with unstable angina pectoris / 中华急诊医学杂志

ABSTRACT

ObjectiveTo inyestigate the effect of miRNA-155 expression on the differentiations and functions of CD4 + T lymphocyte in patients with unstable angina pectoris. MethodsTwenty-one patients with unstable angina pectoris (UAP) were enrolled in this study, and another 18 patients with normal coronary arteries evidenced by angiography were assigned as control group. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of miRNA-155 in CD4 + T lymphocyte of the peripheral blood. And the levels of IFN-γ and IL-4 in serum were determined by using enzyme-linked immunosorbent assay (ELISA). The CD4 + T lymphocyte were isolated from mononuclear cells prepared with Ficoll-Hypaque density-gradients centrifugation from human peripheral blood by magnetic cell sorting system. Then, the CD4 +T cells (2 × 106 cells/mL) were seeded in culture plates with 6 wells.The CD4 + T lymphocytes were divided into 3 groups in experiment: control group, miRNA-155 group, and miRNA-155 inhibitor group. The numbers of Th1 and Th2 cells were measured by flow cytometry analysis (FACS).The protein levels and expressions of IFN-γRα, T-bet, GATA-3 mRNA were measured by using western blotting and qRT-PCR, respectively. The levels of IFN-γ and IL-4 in culture supernatants of CD4 +T lymphocytes were detected by using ELISA. ResultsIn comparison with the control group, there was significant increase in the expression of miRNA-155 and serum level of IFN-γ in the UAP group (P ＜0. 01 ). There was a positive correlation between miRNA-155 and serum IFN-γ ( r =0. 842, P ＜ 0. 0l ).However, in vitro, the number of Th1, the protein level and expression of T-bet mRNA, and supernatant IFN-γ increased, and the protein level and expression of IFN-γRα protein decreased in miRNA-155 group in comparison with the control group (all P ＜0. 01 ). Interestingly, there were no significant differences in the number of Th2 cells, the expressions of GATA-3mRNA and IFN-γRα mRNA, GATA-3 protein and supernatant IL-4 between control group and miRNA-155 group ( all P ＞ 0. 05 ). And the miRNA-155 inhibitor could attenuate the effect of miRNA-155 effectively. ConclusionsThe miRNA-155 can promote differentiations and improve the function of Thl, playing an important role in the pathogenesis of unstable angina pectoris.