The effects of miR-155/miR-21 on the expression of TLR4 in patients with acute Kawasaki disease / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effects of miR-155/miR-21 on the expression of TLR4 in patients with Kawasaki disease (KD).Methods Forty-five children with acute KD were enrolled into the study.Children were divided into the group with coronary artery lesions (KD-CAL+) and the group without coronary artery lesions (KD-CAL-).The age-matched twenty healthy children were included as the control group.The levels of TLR4 expression were analyzed by flow cytometry.The CD14+ monocytes in the peripheral blood were separated by CD14+ immunomagnetic beads.Real-time polymerase chain reaction (PCR) were performed to evaluate the expression of miR-155,miR-21 and interleukin (IL)-10,tumor necrosis factor (TNF)-α,IL-6,IL-1β in CD14+ monocytes at mRNA level.The concentration of matixmetalloproteinase (MMP)-9,HSP60,high mobility group box-1 protein (HMGB1) were measured by enzyme-linked immunosorbentassay (ELISA).T test was used to compare the differences between groups and P＜0.05 was considered to be statistically significant.Results The levels of Toll-like receptor 4 (TLR4) expression in children with acute KD were significantly higher than those in the control group [(12.4±5.1)％ vs (4.6±1.6)％,t=5.55,P＜0.05],and the levels of TLR4 expression in the KD-CAL+ group were remarkably elevated compared with the KD-CAL+group [(17.1±4.6)％ vs (9.6±2.7)％,t=5.89,P＜0.05].The plasma concentrations of HMGB11 [(10.2±7.6 vs 3.2±1.0) ng/ml,t=3.55,P＜0.05] and HSP60 [(56±23 vs 18±7) ng/ml,t=4.90,P＜0.05] in the KD group were increased(P＜0.05),but significantly decreased aftcr treatment with IVIG (P＜0.05).The levels of miR-155 [(21.0±27.0)×10 vs (4.6±3.1)×10-3,t=2.57,P＜0.05] and miR-21 (11.6±4.0 vs 8.7±2.2,t=2.78,P＜0.05)expression in the KD group were significantly higher than those in the controls (P＜0.05).The level of miR-155 expression in the KD-CAL+ group was apparently higher than that in the KD-CAL-group [(4.2±3.0)×10 vs (11.0±1.5)×104,t=4.07,P＜0.05] and the expression of miR-21 was lower than that in the KD-CAL-group (8.8±2.5 vs 12.8±4.0,t=3.46,P＜0.05).Compared with the controls,the levels of IL-10 mRNA expression in the KD group were significantly increased [(34.9 ±17.5)×10 vs (1.0±9.4)×10 4,t =5.62,P＜0.05),and IL-10 expression in the KD-CAL-group was higher than that in the KD-CAL+ group [(26.6±13.4)×104 vs (39.5±1.8)×10,t=2.36,P＜0.05].The plasma concentrations of MMP-9 in the KD group were remarkably higher than those in the controls [(1 141±541) pg/ml vs (304±94) pg/ml,t=4.83,P＜0.05],the concentration of MMP-9 in the KD-CAL+ group was higher than that in the KD-CAL-group [(1 350±625) pg/ml vs (945±370) pg/ml,t=2.21,P＜0.05].Conclusion The dysregulation of miR-155 and miR-21 may be one of the reasons that result in over-expression of TLR4 in patients with acute KD,and the persistently increased HSP60 and HMGB1 may trigger or amplify TLR4 expression.