摘要:
目的 探讨高迁移率族蛋白1 (hfigh-mobility group box 1, HMGB1) 在呼吸道合胞病毒支气管肺炎患儿中的作用及相关机制.方法 选取2016年6月至2017年6月在云南省第二人民医院就诊的呼吸道合胞病毒支气管肺炎患儿和同期在本院做体检的健康儿童各46例分别作为试验组和对照组, 收集外周血样品.通过酶联免疫吸附试验检测促炎性细胞因子IL-1β、IL-6、IL-8、TNF-α、hs-CRP以及HMGB1在两组外周血中的表达.通过流式分析, 检测对照组和试验组外周血单个核细胞中Toll样受体4 (toll-like receptor, TLR4) 和核转录因子 (nuclear factor kappa B, NFκB) 的表达量.在细胞水平上, 用合胞病毒 (respiratory syncytial virus, RSV) 感染支气管上皮细胞NHBE后, 利用Western blot检测HMGB1干扰组和对照组中TLR4、NFκB的表达, 利用ELISA检测炎性因子的分泌情况.结果 试验组HMGB1、TLR4、NFκB和炎性因子 (IL-6、IL-8、TNF-α、hs-CRP) 的表达水平均明显高于对照组.在细胞水平上发现合胞病毒可诱导支气管上皮细胞NHBE中HMGB1的表达和分泌, 并增加TLR4、NFκB的表达, 促进炎性因子IL-6、IL-8、TNF-α、hs-CRP的分泌.用HMGB1shRNA干扰序列, 干扰HMGB1的表达, 发现TLR4的表达明显下调, 炎性因子分泌减少.结论 HMGB1及其介导的TLR4/NFκB信号通路在呼吸道合胞病毒支气管肺炎患儿中高表达, 特异性干扰HMGB1可抑制TLR4/NFκB信号通路, 缓解呼吸道合胞病毒诱导支气管上皮细胞分泌炎性因子.%Objective To investigate the role and mechanism of high-mobility group box 1 (HMGB1) in children with respiratory syncytial virus (RSV) bronchopneumonia.Methods A total of 46 children with RSV bronchopneumonia treated in The Second Hospital of Yunnan Province from June of 2016 to June of 2017 were selected into the experiment group and the other 46 healthy children receiving the physical examination over the corresponding period were enrolled into the control group.The peripheral blood samples of the two groups were collected and Enzyme linked immunosorbent assay (ELISA) was used to detect the expression levels of the inflammatory cytokines including IL-1β, IL-6, IL-8, TNF-α, hs-CRP and HMGB1.The expression levels of Tolllike receptor 4 (TLR4) and nuclear factor kappa B (NFκB) in the peripheral blood mononuclear cells in the control group and the experiment group were detected.At the cell level, the expression levels of TLR4 and NFκB in the HMGB1 interference group and the control group was detected by Western blot after the infection to NHBE of the bronchial epithelial cells with RSV and the secretion of inflammatory factors was detected by ELISA.Results The expression levels of HMGB1, TLR4, NFκB, IL-6, IL-8, TNF-αand hs-CRP were significantly higher in the experiment group than in the control group.At the cellular level, RSV induced the expression and secretion of HMGB1 in the bronchial epithelial cell NHBE, increased the expression of TLR4 and NFκB and promoted the secretion of IL-6, IL-8, TNF-αand hs-CRP.By using HMGB1 shRNA to interfere with HMGB1 expression, it was found that the TLR4 expression was significantly down-regulated and the secretion of inflammatory factors decreased.Conclusion HMGB1 and the TLR4/NFκB signaling pathway mediated by HMGB1 are highly expressed in children with RSV bronchopneumonia, and the specific interference HMGB1 inhibits the TLR4/NFκB signaling pathway and alleviates the secretion of the inflammatory factors in RSV-induced bronchial epithelial cells.