程序性细胞死亡因子-1在大鼠肺缺血再灌注损伤中的作用

The role of PD-1 in lung ischemia-reperfusion injury in rats

目的探讨程序性细胞死亡因子-1(PD-1)在大鼠肺缺血再灌注损伤中的作用与机制。方法将30只SD大鼠随机分成对照组、再灌注2 h组、再灌注6 h组、再灌注24 h组、再灌注72 h组,每组6只。采用左肺门全夹闭法造肺缺血再灌注模型。各组取左肺组织。计算肺组织湿干重比值(W/D);用HE染色法和电镜观察肺组织病理学变化;采用ELISA法检测肺组织IL-1β、IL-4、IL-6、IL-10水平;采用Western Blot法检测肺组织PD-1表达;采用免疫组化法检测肺组织CD11c、CD16、CD206、Arg1的表达。结果与对照组比,肺缺血再灌注2 h组开始有肺损伤,包括肺组织形态学和微结构的改变,肺损伤评分升高,再灌注6 h组损伤最严重,而后损伤程度逐渐减轻(P <0.05)。与对照组比,各实验组肺组织IL-1β、IL-4、IL-6、IL-10水平升高(P <0.05);其中,IL-1、IL-6、IL-10于再灌注6 h组达到高峰;IL-4于再灌注24 h组达到高峰。Western Blot显示,与对照组比,各实验组PD-1表达增高(P <0.05);其中再灌注6 h组表达最高。免疫组化显示,与对照组比,肺组织CD11c、CD16、CD206、Arg1在再灌注6 h组表达增高(P <0.05);与再灌注6 h组比,再灌注72 h组表达降低(P <0.05)。结论 PD-1可能参与了大鼠肺缺血再灌注损伤的发生,其机制可能与PD-1介导的肺巨噬细胞极化导致的炎症反应有关。

Objective To investigate the role of PD-1 in lung ischemia-reperfusion(I/R)injury of rat model.Methods Thirty Sprague-Dawley rats were randomly divided into five groups:Control group,2 hours post I/R group,6 hours post I/R group,24 hours post I/R group,72 hours post I/R group,six animals in each.I/R models were established by clamping the left hilum.The degree of pulmonary edema were tested by left lung W/D.Hematoxylin-eosin(HE)staining and transmission electron microscopy(TEM)were used to assess the extent of lung injury.The concentration of IL-1β,IL-4,IL-6 and IL-10 in lung tissue was detected by ELISA.The expression of PD-1 in lung tissue was measured by Western Blot.The expression of CD11c,CD16,CD206 and Arg1 in lung tissues was analyzed by immunohistochemistry.Results Compared with the control group,2 hours post I/R group showed lung injury and 6 hours post I/R group was the most serious(P<0.05).Significantly increased concentration of IL-1β,IL-6 and IL-10 in lung tissue in 6 hours post I/R group(P<0.05).IL-4 level gradually increased and reached a peak at 24 hours(P<0.05).Expression of PD-1 in lung tissues was increased most in 6 hours post I/R group(P<0.05).Expression of CD11c,CD16,CD206 and Arg1 in lung tissues were increased in 6 hours post I/R group(P<0.05).Conclusion Changes of PD-1 might be closely related to lung ischemia-reperfusion injury in rats.The mechanism may be related to the inflammatory reaction induced by PD-1 mediated pulmonary macrophage polarization.