Effects of moderate oxygen concentration on A549 cells and expression of TGF-β1 mRNA and CTGF mRNA in A549 cells

Abstract

Objective To evaluate the effects of moderate oxygen concentration (40％ O2) on A549 cells and expression of transforming growth factor-β1 (TGF-β1) mRNA and connective tissue growth factor (CTGF) mRNA in A549 cells.Methods Cultured A549 cells were seeded in 6-well plates (1 mYhole) or in 10 cm diameter dishes (5 ml/dish) with the density of 1 × 1O5 cells/ml and randomly divided into 3 groups (n =12 each) using a random number table:control group (group C),40％ oxygen concentration group (group 40％ O2),and 95％ oxygen concentration group (group 95 ％ O2).A549 cells were exposed to air,40 ％ O2 and 95 ％ O2 for 48 h in C,40％ O2 and 95％ O2 groups,respectively.The necrosis and expression of TGF-β1 mRNA and CTGF mRNA were detected at the end of culture.Results Compared with group C,the necrosis rate was significantly increased,while the expression of TGF-β1 mRNA and CTGF mRNA was up-regulated in 40％ O2 and 95％ O2 groups (P ＜ 0.05).Compared with group 95 ％ O2,the necrosis rate was significantly decreased,while the expression of TGF-β1 mRNA was down-regulated (P ＜ 0.05),and there was no significant difference in CTGF mRNA expression in group 40 ％ O2 (P ＞ 0.05).Conclusion Exposure to moderate oxygen concentration for a certain time can induce damage to A549 cells,but the severity is lighter than that caused by high oxygen concentration,and up-regulation of TGF-β1 and CTGF gene expression may be involved in the mechanism. Key words: Oxygen; Epithelial cells; Pulmonary alveoli; Transforming growth factor betal ; Connective tissue growth factor; RNA, messenger