The Effects Of MiR-155/miR-21 On The Expressiion Of TLR4 In Patients With Acute Kawasaki Disease

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 group with coronary artery lesions(KD-CAL+) and group without coronary artery lesions(KD-CAL-).The age-matched twenty healthy children as healthy control group were included in the study.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 PCR were performed to evaluate the expression of miR-155,miR-21and IL-10,TNF-a,IL-6,IL-1β in CD14+ monocytes at mRNA level.The concentration of MMP-9,HSP60,HMGBlwere measured by enzyme-linked immunosorbent assay.Results The levels of TLR4 expression in children with acute KD were significantly higher than those in control group(P<0.05),and the levels of TLR4 expression in KD-CAL+ group were remarkably elaveted compared with KD-CAL+ group (P＜0.05); The plasma concentrations of HSP60 and HMGB1 in KD group were increased(P<0.05),but significantly decreased after treatment with IVIG(P<0.05); The levels of miR-155 and miR-21 expression in KD group were significantly higher than those in controls(P<0.05); The level of miR-155 expression in KD-CAL+ group was apparently higher than that in KD-CAL- group and the expression of miR-21 was lower than that in KD-CAL- group;Compared with controls,the levels of IL-10 mRNA expression in KD group were significantly increased(P<0.05),and IL-10 expression in KD-CAL- group was higher than that in KD-CAL+ group(P<0.05); The plasma concentrations of MMP-9 in KD group were remarkably higher than those in controls(P<0.05),the concentration of MMP-9 in KD-CAL+ group were higher than those in KD-CAL- group(P<0.05).Conclusions The dysregulation of miR-155 and miR-21 might be one of reasons that resulting in over-expression of TLR4 in patients with acute KD,and the persistently increased HSP60 and HMGB1 might trigger or amplify TLR4 expression.