失血性休克诱导小鼠肺组织巨噬细胞TLR4原位表达的变化

TLR4 expression in situ on pulmonary macrophages of hemorrhage - induced acute lung injury in mice

目的复制失血性休克致急性肺损伤（ALI）模型，原位观察其肺组织巨噬细胞TLR4表达的变化及其意义。方法32只C57BL／6雄性小鼠随机分为两组：NCG组为空白对照组，PCG组为单纯失血性休克组，分别于失血性休克后1、2、4、6h处死小鼠。观察肺组织病理变化，EMSA检测肺组织核转录因子-κB（NF—κB）活性，ELISA检测肺组织肿瘤坏死因子-α（TNF-α）水平，激光共聚焦观察肺巨噬细胞TLR4原位表达的变化。结果失血性休克诱导的ALI肺组织病理显示，随时间变化肺部损伤逐渐加重，NF—κB活性及TNF-α水平均随时间变化逐渐增加，与NCG组比较差异有统计学意义（P〈0．05），原位观察肺巨噬细胞TLR4的表达亦随时间变化逐渐增加。结论失血性休克诱导小鼠肺部的炎症反应，肺巨噬细胞TLR4的表达随时间变化逐渐增加，调控肺巨噬细胞TLR4的表达可能成为早期治疗失血性休克诱导ALI的一个新的途径。

Objective To reproduce model of hemorrhage - induced acute lung injury and to observe TLR4 expression in situ on pulmonary macrophages of hemorrhage - induced acute lung injury in mice. Methods 32 male C57BL/6 mice were randomly divided into two groups. The NCG was blank control group, which accepted cardiac puncture without shock. The PCG was hemorrhagic shock group before cardiac puncture. Lungs of mice were harvested at 1,2, 4 and 6 h after hemorrhagic shock. The pathology in lungs was determined by HE dyeing. The activation of NF - κB was determined by electrophoretic mobility shift assay （EMSA）. The TNF - α was detected by enzyme - linked immunosorbent assay（ELISA）. The TLR4 expressions in situ on pulmonary macrophages were detected by double immunofluorescence staining. Results Obviously widening interalveolar septum, lots of lung neutrophil accumulation and erythrocyte effusion, many macrophages and polymorphonuclear leucocytes in alveolar space were observed at 6 h after hemorrhagic shock. The NF - κB activation in lungs gradually increased at 1,2, 4 h and decreased at 6 h, and the TNF -α gradually increased at 1, 2, 4 and 6 h. The NF -κB activation and TNF - α in PCG was much better than in NCG（P 〈0.05）. TLR4 expression in situ on pulmonary macrophages gradually increased at 1,2, 4 and 6 h. Conclusions The TLR4 expression in situ on pulmonary macrophages gradually increases after hemorrhage - induced acute lung injury and enhances inflammatory reaction. Regulation of the TLR4 expression of pulmonary macrophages would be one new way to prevention and cure of hemorrhage - induced acute lung injury at the early stage.