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目的探索高体积分数氧(高氧)致A549细胞肺表面活性物质蛋白(SP)-A表达的变化规律。方法将A549细胞分为高氧组和常氧组。高氧组细胞置于含950 mL·L-1氧气和50 mL·L-1二氧化碳的条件下培养,常氧组以空气替代氧气,于0 h、12 h、24 h、48 h、72 h、96 h在倒置相差显微镜下观察细胞生长状况,提取细胞内总蛋白,采用硫代巴比妥酸比色法检测其丙二醛(MDA)水平,Western blot检测其SP-A表达水平。结果高氧48 h可导致A549细胞生长明显减慢,72 h后细胞生长停滞,可见较多漂浮死亡细胞,96 h后漂浮死亡细胞明显增多。高氧组各时间点A549细胞SP-A表达水平均高于常氧组,高氧24 h SP-A表达增多最显著,此后增多的幅度逐渐减小,高氧48 h后细胞内MDA水平显著高于常氧组,随时间延长,MDA水平进一步升高。结论高氧可导致A549细胞损伤,SP-A表达在细胞高氧损伤早期代偿性增加,晚期降低,推测SP-A表达降低可能与细胞损伤加重有关,增加SP-A的表达可能有助于减轻高氧引起的细胞损伤。
Objective To explore the changes of pulmonary surfactant protein (SP) -A expression in A549 cells induced by high volume fraction of oxygen (hyperoxia). A549 cells were divided into hyperoxia group and normoxia group. The cells in hyperoxia group were cultured in the medium containing 950 mL · L-1 oxygen and 50 mL · L-1 carbon dioxide. The normoxia group was replaced by air at 0 h, 12 h, 24 h, 48 h, 72 h , And the cell growth was observed under an inverted phase contrast microscope at 96 hours. Total cellular protein was extracted. The level of malondialdehyde (MDA) was detected by thiobarbituric acid colorimetric assay. The expression of SP-A was detected by Western blot. Results After 48 h of hyperoxia, the growth of A549 cells was obviously slowed down. After 72 h, the growth of cells was arrested. More dead cells could be seen floating, and the number of floating dead cells increased obviously after 96 h. The expression of SP-A in A549 cells at each time point in hyperoxia group was higher than that in normoxia group. The expression of SP-A increased most significantly after 24 hours of hyperoxia, and then increased gradually. The level of MDA in the cells increased significantly after 48 hours of hyperoxia Higher than the normoxic group, with the prolongation of time, MDA levels increased further. Conclusions The hyperoxia can cause the injury of A549 cells. The expression of SP-A is compensatory increased in the early stage of hyperoxia injury and decreased in late stage. It is speculated that the decrease of SP-A expression may be related to the increased cell injury. Increasing SP-A expression may contribute to Reduce cell damage caused by hyperoxia.