光气对小鼠肺上皮细胞和内皮细胞凋亡的诱导作用

Apoptosis of pulmonary epithelial cells and endothelial cells in mice exposed to phosgene

目的研究光气对肺水肿小鼠肺上皮细胞和内皮细胞凋亡的诱导作用。方法将32只BALB/C小鼠随机分成正常对照组(16只)和染毒组(16只)2组。正常对照组小鼠以空气为对照,染毒组小鼠给予11.9mg/L剂量的光气,时间为5min。染毒后4h,取小鼠分离、培养肺Ⅱ型细胞用于电镜观察和流式细胞仪检测细胞凋亡,取小鼠肺脏进行DNA琼脂糖凝胶电泳和TUNEL染色检测肺组织凋亡。结果光气染毒肺水肿小鼠电镜下原代肺Ⅱ型细胞出现凋亡小体;流式细胞术显示肺Ⅱ型细胞凋亡率(40.26±7.74)显著高于正常对照组(1.58±1.01,P<0.001);DNA琼脂糖凝胶电泳出现"DNA梯状改变";TUNEL染色检测到肺上皮细胞和血管内皮细胞凋亡。结论光气染毒可造成肺水肿小鼠肺脏细胞发生凋亡,提示光气造成小鼠肺水肿的发生机制存在细胞凋亡的诱导作用。

Objective To study apoptosis of pulmonary epithelial cells and endothelial cells in mice with pulmonary edema induced by phosgene exposure. Methods Thirty-two mice were divided into normal group and phosgene group with 16 mice in each group. The mice in phosgene group were exposed to phosgene （11.9 mg/L） for 5 min and those in the control group to air. Four hours after exposure, alveolar type Ⅱcells were isolated and cultured to observe their apoptosis by electron microscope and flow cytometry. The lung tissues were also taken for DNA gel electrophoresis and TUNEL assay. Results Apoptotic bodies were observed in alveolar type Ⅱcells under electron microscope in phosgene group, which had higher cell apoptosis rate than the control group [（40.26±7.74）% vs （1.58± 1.01）%, P〈0.001 ] as determined by flow cytometry. Ladder-like DNA fragmentation pattern was observed in DNA gel electrophoresis in phosgene group with apoptosis of the pulmonary epithelial and endothelial cells observed by TUNEL. Conclusions Phosgene can induce pulmonary epithelial and endothelial cell apoptosis in mice, suggesting that the mechanism of phosgene-induced pulmonary edema involves apoptosis of the lung cells.