摘要
目的探讨程序性死亡配体-1(PD-L1)在肺微血管内皮细胞或肺上皮细胞的表达及其在小鼠间接急性肺损伤(i-ALI)模型中的作用及机制。方法将80只雄性C57BL/6小鼠随机分为两部分(均n=40),分别观察不同给药途径对PD-L1表达的影响。每部分小鼠按照随机数字表法分为假手术(Sham)组、i-ALI组、i-ALI+小干扰RNA(siRNA)随机序列对照组及i-ALI+含可特异性抑制PD-L1表达碱基对的siRNA(PD-L1siRNA)组,每组10只。采用失血性休克联合盲肠结扎穿孔术(CLP)"二次打击"诱导i-ALI模型;Sham组仅结扎双侧股动脉,不予置管及放血,且仅分离盲肠但不结扎穿孔。i-ALI+PD-L1siRNA组于小鼠休克复苏2h后分别经尾静脉或气道内给予PD-L1siRNA阻断肺微血管内皮细胞或肺上皮细胞PD-L1的表达;i-ALI+siRNA随机序列对照组给予无抑制PD-L1表达效应的siRNA随机序列;Sham组和i-ALI组给予100μL磷酸盐缓冲液(PBS)。CLP术后24h处死小鼠,收集外周血、肺组织及支气管肺泡灌洗液(BALF),用流式细胞仪检测PD-L1蛋白表达,用酶联免疫吸附试验(ELISA)检测外周血、肺组织以及BALF中的细胞因子和趋化因子水平,定量检测血浆和BALF中蛋白浓度及肺组织中髓过氧化物酶(MPO)活性,光镜下观察肺组织病理学改变。结果①与Sham组相比,i-ALI组肺微血管内皮细胞或肺上皮细胞PD-L1的表达均明显升高〔肺内皮细胞:(27.88±1.53)%比(19.64±1.03)%,肺上皮细胞:(58.70±8.21)%比(29.23±3.94)%,均P<0.05〕。②经尾静脉给予PD-L1siRNA可以抑制肺微血管内皮细胞PD-L1的表达〔与i-ALI组比较:(21.37±0.76)%比(27.88±1.53)%,P<0.05〕;经气道内给予PD-L1siRNA主要抑制肺上皮细胞PD-L1的表达〔与i-ALI组比较:(31.23±4.71)%比(58.70±8.21)%,P<0.05〕。给予siRNA随机序列对i-ALI小鼠肺微血管内皮细胞或肺上皮细胞PD-L1的表达均无影响。③经尾静脉给予PD-L1siRNA抑制肺微血管内皮细胞PD-L1的表达后,BALF/血浆的蛋白比�
Objective To examine the expression profile of programmed death-ligand 1 (PD-L1) on lung endothelial or epithelial cells, and to determine the specific role of PD-L1 in mouse model of indirect acute lung injury (i-ALI).Methods Eighty male C57BL/6 mice were randomly divided into two parts (both n = 40). The effects of different administration routes on the expression of PD-L1 were observed. The mice in each part were randomly divided into sham, i-ALI, i-ALI+small interfering RNA (siRNA) random sequence control, and i-ALI+PD-L1 siRNA which could specifically inhibit PD-L1 expression groups, with 10 mice in each group. i-ALI was reproduced in a mouse model of hemorrhagic shock in combination with a subsequent cecal ligation and puncture (CLP). In sham group, only bilateral femoral arteries were ligated without catheterization or bleeding, and only cecum was separated but perforation was not ligated. Intravenous or intratracheal delivery of PD-L1 siRNA was performed 2 hours following the resuscitation to suppress the expression of PD-L1 on lung endothelial or epithelial cells. The mice in i-ALI+siRNA random sequence control group were given siRNA random sequence without inhibition effect on PD-L1 expression, and those in sham group and i-ALI group were given 100 μL phosphate buffered saline (PBS). The mice were sacrificed at 24 hours after CLP, and samples of blood, lung tissue and bronchoalveolar lavage fluid (BALF) were harvested. Expressions of PD-L1 were determined with flow cytometry. Cytokines and chemokines in plasma, lung tissue and BALF were determined by enzyme linked immunosorbent assay (ELISA). The protein concentration in plasma and BALF and the activity of myeloperoxidase (MPO) in lung tissue were quantitatively measured. The pathological changes in lung tissue were observed under light microscope.Results ① Compared with sham group, PD-L1 expression on lung endothelial or epithelial cells were significantly elevated in i-ALI group [endothelial cells: (27.88±1.53)% vs. (19.64±1.03)%, epithelial cell
作者
孙冰珂
李秀华
郑贵珍
董天操
李玉生
李红强
燕艳丽
白建文
许淑敏
Sun Bingke;Li Xiuhua;Zheng Guizhen;Dong Tiancao;Li Yusheng;Li Hongqiang;Yan Yanli;Bai Jianwen;Xu Shumin(Department of lnternal Emergency Medicine,East Hospital,Tongji University,Shanghai 200120,China)
出处
《中华危重病急救医学》
CAS
CSCD
北大核心
2019年第1期37-43,共7页
Chinese Critical Care Medicine
基金
国家自然科学基金青年科学基金(81800081).
