Effects of microRNA-155 on interleukin-1 receptor-associated kinase 1 and 4 mRNA expression in liver injury of endotoximia mice / 中国小儿急救医学

ABSTRACT

Objective To explore the protective effect of rnicroRNA (miRNA)-155 inhibitor on interleukin-1 receptor-associated kinase (IRAK)-1 mRNA and IRAK-4 mRNA in endotoximia induced liver injury in mice.Methods One hundred and twenty male BALB/c mice were randomly divided into healthy control group(n =40),endotoximia group (n =40) and miRNA-155 inhibitor group (n =40).Each group were divided into 6 h,12 h,24 h,48 h subgroups,each of which consisted of 10 mice.The mice in miRNA-155 inhibitor group were administered with miRNA-155 inhibitor[80 mg(kg ·d)] via tail vein injection before lipopolysaccharide (LPS) administration while the other two groups treated with normal saline,following 24 hours,model of endotoximia mice was produced by injection of LPS intraperitoneally.At 6 h,12 h,24 h,48 h after LPS exposure,the experimental mice were sacrificed and the liver tissue samples were collected.Histopathological changes,the expression of miRNA-155,IRAK-1 mRNA,IRAK-4 mRNA,tumor necrosis factor (TNF)-α,IL-1,IL-10 were detected.Results LPS exposure resulted in increase of miRNA-155,IRAK-1 mRNA,IRAK-4 mRNA,TNF-α,IL-1 and IL-10 in both endotoximia group and miRNA-155 inhibitor group compared to the control group,miRNA-155 inhibitor resulted in decrease of miRNA-155,IRAK-1 mRNA,IRAK-4 mRNA,TNF-α,IL-1 and IL-10 in miRNA-155 inhibitor group compared to the endotoximia group.There were significant differences of miRNA-155 expression at 12 h,24 h,48 h after LPS exposure among 3 groups (P ＜ 0.05).Both IRAK-1 mRNA and IRAK-4 mRNA showed significant differences at 12 h,24 h,48 h.Turning to inflammation factors,differences were found among 3 groups at all time points (P ＜ 0.05).At light-scope,there was improvement in sepsis associated liver injury in miRNA-155 inhibitor group compared to endotoximia group.Conclusion miRNA-155 inhibitor administration appears to down regulate IRAK-1 mRNA and IRAK-4 mRNA expression and further deduce the excessive inflammatory and anti-inflammatory reaction,which may alleviate liver injury in endotoximia mice.