Abstract: Objective　To study the effect of different concentrations of recombinant human erthropoietin（rhEPO）on reducing the apoptosis of human typeⅡ alveolar epithelial cells（A549 cells）induced by hyperoxia.Methods　From January to December 2017，cultured A549 cells during logarithmic growth phase were randomly divided into the control group（receiving incubation in a 50 ml/L CO2 incubator with a constant temperature of 37 ℃），hyperoxic group（receiving airtight laboratory incubation after passing through the high purity gas mixtures of 900 ml/L O2 and 50 ml/L CO2 supplied for 10 min with a velocity of 3 L/min）and 10，20，50，100 U/ml rhEPO groups（receiving hyperoxic induction after being pretreated for 24 hours in a culture medium containing 10，20，50，100 U/ml rhEPO，respectively）．Each group contained 8 complex pores.24 hours later，the morphological changes of cells in each group were observed by inverted phase contrast microscope，cell proliferation level was measured by cell proliferation assay，and apoptosis rate was detected by flow cytometry.Results　In terms of cell morphology，the hyperoxic group presented rather enlarged intercellular space between remarkably damaged cells，significantly decreased living cells and increased suspended cells；all rhEPO groups showed improvement in damaged cells，in particular，50，100 U/ml rhEPO groups demonstrated morphological changes similar to those of the control group.With regard to cell proliferation level，the control group had higher cell proliferation level than the hyperoxic group and 10，20 U/ml rhEPO groups（P<0.05）；all rhEPO groups showed higher cell proliferation level than the hyperoxic group（P<0.05）；50，100 U/ml rhEPO groups had higher cell proliferation level when compared with 10，20 U/ml rhEPO groups，so did the 100 U/ml rhEPO group when compared with the 50 U/ml rhEPO group（P<0.05）．In respect of cell apoptosis rate，the control group exhibited lower cell apoptosis rate than the hyperoxic group and 10，20 U/ml rhEPO groups（P<0.05）；all rhEPO groups showed lower cell apoptosis rate than the hyperoxic group（P<0.05）；50，100 U/ml rhEPO groups showed lower cell apoptosis rate when compared with 10，20 U/ml rhEPO groups，so did the 100 U/ml rhEPO group when compared with the 50 U/ml rhEPO group（P<0.05）．Conclusion　rhEPO can improve the suppressed proliferation and increased apoptosis of A549 cells caused by hyperoxia，in particular，50 and 100 U/ml rhEPO can effectively protect the A549 cells from hypoxic injury.

Key words: Lung injury, Hyperoxia, Cell proliferation, Apoptosis, Recombinant human erthropoietin, Human type Ⅱ alveolar epithelial cells

摘要： 目的　探讨不同浓度重组人促红细胞生成素（rhEPO）对高氧暴露下人肺泡Ⅱ型上皮细胞（A549细胞）功能的影响。方法　2017年1—12月，培养A549细胞，取对数生长期的A549细胞，将其随机分为对照组（将细胞置于37 ℃恒温的50 ml/L CO2培养箱中进行培养）、高氧组（以3 L/min速度通过900 ml/L O2和50 ml/L CO2高纯混合气，持续通气10 min，之后进行密闭培养）及10、20、50、100 U/ml rhEPO组（分别将细胞加入含10、20、50、100 U/ml rhEPO的培养基，之后预处理24 h，再用高氧诱导），每组中包含8个复孔。24 h后，采用倒置相差显微镜观察各组细胞形态学变化，细胞增殖实验检测细胞增殖水平，流式细胞术检测细胞凋亡率。结果　高氧组细胞间空隙较大，细胞受损明显，活细胞数量显著降低，悬浮细胞明显增多；10、20、50、100 U/ml rhEPO组细胞损伤改善，50、100 U/ml rhEPO组细胞形态学变化与对照组较为相似。高氧组及10、20 U/ml rhEPO组细胞增殖水平小于对照组（P<0.05）；10、20、50、100 U/ml rhEPO组细胞增殖水平大于高氧组（P<0.05）；50、100 U/ml rhEPO组细胞增殖水平大于10、20 U/ml rhEPO组（P<0.05）；100 U/ml rhEPO组细胞增殖水平大于50 U/ml rhEPO组（P<0.05）。高氧组及10、20 U/ml rhEPO组细胞凋亡率大于对照组（P<0.05）；10、20、50、100 U/ml rhEPO组细胞凋亡率小于高氧组（P<0.05）；50、100 U/ml rhEPO组细胞凋亡率小于10、20 U/ml rhEPO组（P<0.05）；100 U/ml rhEPO组细胞凋亡率小于50 U/ml rhEPO组（P<0.05）。结论　高氧抑制A549细胞增殖、促进A549细胞凋亡，而rhEPO可减轻这种作用，且50、100 U/ml rhEPO能有效抑制A549细胞发生损伤。

关键词: 肺损伤, 高氧症, 细胞增殖, 细胞凋亡, 重组人促红细胞生成素, 人肺泡Ⅱ型上皮细胞