ABSTRACT
Objective To explore the role of microRNA-206 (miR-206) in peripheral blood mononuclear cells (PBMCs) in infantile bronchiolitis caused by respiratory syncytial virus (RSV).Methods Thirty-five cases of infantile bronchiolitis and 25 cases of healthy controls were enrolled into the current study.PBMCs were isolated from the peripheral blood of both healthy subjects and those with infantile bronchiolitis in the acute and the convalescent stages.Total RNAs were extracted from PBMCs which were stimulated by phorbol-12-myristate-13-acetate (PMA) and Ionomycin, and then the RNA was transcribed reversely into cDNA.The expressions of miR-206 and Kruppel-like transcription factor 4 (KLF4) were detected by real-time quantitative polymerase chain reaction (qRT-PCR) method.Plasma interleukin-17 (IL-17) was determined by enzyme linked immunosorbent assay (ELISA).Results There was a significant difference in miR-206 levels of children with RSV bronchiolitis in the acute stage(0.055 ±0.018) and the convalescent stage(0.187 ±0.069) as well as the healthy controls(0.204 ± 0.075).Through pairwise comparison, the miR-206 levels in the children in the acute stage were significantly lower than those in the convalescent stage and healthy control group (P ＜ 0.01), but no statistical significance was found between the convalescent stage group and healthy control group(P ＞ 0.05).The levels of KLF4 mRNA of children in the acute stage,convalescent stage as well as the healthy subjects were 0.588 ± 0.161,0.086±0.024,0.075 ±0.019, respectively,which was significantly difference (P ＜ 0.01).The levels of IL-17 were (58.26 ±25.88) ng/L, (9.87 ± 3.01) ng/L, (7.65 ± 2.16) ng/L, respectively (P ＜ 0.01).Compared to the convalescent and the normal control group,both the KLF4 mRNA and IL-17 levels were markedly higher in the acute stage (P ＜ 0.01), but there were no significant differences between children with RSV bronchiolitis in convalescent stage and in the healthy controls (P ＞ 0.05).Furthermore, the result of this study showed a negative correlation between the expression of miR-206 and KLF4(r =-0.624 ,P ＜0.01)and IL-17 (r =-0.609 ,P ＜0.01) in children in the acute stage and a positive correlation between KLF4 mRNA and IL-17 in children in the acute stage (r =0.662, P ＜ 0.01).Conclusion The levels of miR-206 may play a role in the onset of RSV associated post-bronchiolitis (PB) and the low expression of miR-206 in children infected with RSV may increase the susceptibility to PB.