肺炎支原体感染患儿miR-29c靶向B7-H3作用机制

Mechanism of miR-29c targeting B7-H3 in children with Mycoplasma pneumoniae infection

目的探究在肺炎支原体感染患儿中的miR-29c-3p(miR-29c)靶向B7同源性3(B7-H3)作用机制。方法选择成都儿童专科医院2018年2月-2020年10月收治的230例肺炎支原体感染患儿以及在医院体检100名健康儿童作为研究对象。测定所有儿童miR-29c、B7-H3及相关细胞因子水平;体外细胞实验确定miR-29c靶向B7-H3作用具体机制。结果研究组患儿miR-29c低于对照组,而B7-H3、IL-4、IL-17高于对照组(P<0.05);与空白对照组比较,miR-29c沉默组IL-4水平上升,IL-17、干扰素(IFN)-γ、磷酸化信号转导与转录激活因子3(p-STAT3)蛋白、B7-H3蛋白水平下降(P<0.05),miR-29c过表达组IL-4水平下降,IL-17、IFN-γ、STAT3蛋白、B7-H3蛋白水平上升(P<0.05);与“miR-29c+荧光素酶空载”组、“miR-29c+B7-H3-mut-3’-UTR”组比较,“miR-29c+B7-H3-3’-UTR”组荧光素酶表达量下降(P<0.05);与CD_(4)^(+)T细胞组比较,空白病毒巨噬细胞+CD_(4)^(+)T细胞组、miR-29c沉默巨噬细胞+CD_(4)^(+)T细胞组视黄酸相关的孤儿受体(ROR-γt)、T-bet下降,GATA3上升(P<0.05);与空白病毒巨噬细胞+CD_(4)^(+)T细胞组比较,miR-29c沉默巨噬细胞+CD_(4)^(+)T细胞组ROR-γt、T-bet下降,GATA3上升(P<0.05)。结论miR-29c通过上调B7-H3水平影响支原体肺炎感染患儿机体炎症反应,这一作用可能与miR-29c调节B7-H3水平影响巨噬细胞极化,促进CD_(4)^(+)T细胞分化有关。

OBJECTIVE To explore the mechanism of miR-29 c targeting B7-H3 in children with Mycoplasma pneumoniae infection.METHODS Total of 230 children with Mycoplasma pneumoniae infection admitted to Chengdu Children’s Hospital between Feb 2018 and Oct 2020 were recruited in the study group,and 100 healthy children who received physical examination in the hospital during the same period were enrolled as the control group.The levels of miR-29 c,B7-H3 and related cytokines were measured,and the mechanism of miR-29 c targeting B7-H3 was confirmed by in vitro cell experiments.RESULTS The level of miR-29 c in the study group was significantly lower than that in the control group,while the levels of B7-H3,IL-4 and IL-17 were significantly higher than those in the control group(P<0.05).Compared with the control group,the IL-4 level in the miR-29 c silencing group was increased,while the levels of IL-17,interferon(IFN)-γ,phosphorylated signal transducer and activator of transcription 3(p-STAT3)protein,and B7-H3 protein decreased(P<0.05).The IL-4 level in the miR-29 c overexpression group decreased,while the levels of IL-17,IFN-γ,STAT3 protein,and B7-H3 protein increased significantly(P<0.05).Compared with the miR-29 c+luciferase unloaded group and the miR-29 c+B7-H3-mut-3’-UTR group,the expression of luciferase in the miR-29 c+B7-H3-3’-UTR group was significantly decreased(P<0.05).Compared with the CD_(4)^(+)T cell group,the retinoid-related orphan receptor-gammat(RORγt)and T-bet in the blank virus macrophage+CD_(4)^(+)T cell group and the miR-29 c silenced macrophage+CD_(4)^(+)T cell group decreased significantly,while GATA3 increased significantly(P<0.05).Compared with the blank virus macrophage+CD_(4)^(+)T cell group,RORγt and T-bet in the miR-29 c silenced macrophage+CD_(4)^(+)T cell group decreased significantly,while GATA3 increased significantly(P<0.05).CONCLUSION MiR-29 c influences inflammatory response in children with Mycoplasma pneumonia infection by up-regulating the expression level of B7-H3,which may affect the polarization of macrophages and promote the differentiation of CD_(4)^(+)T cells.