地塞米松对高氧诱导的人胚肺成纤维细胞增殖及成纤维细胞生长因子 mRNA 表达的影响

Effect of Dexamethasone on proliferation and expression of fibroblast growth factor mRNA in human embryo lung fibroblasts exposed to hyperoxia

目的：探讨不同浓度地塞米松（ DEX）对高体积分数氧（高氧）暴露下人胚肺成纤维细胞（MRC-5）增殖及其成纤维细胞生长因子（FGF）-1、FGF-2和白细胞介素-6（IL-6）mRNA 表达的影响。方法950 mL/ L 的高氧制作高氧损伤细胞模型，予不同浓度 DEX（10-4、10-6、10-8、10-9、10-10、10-11、10-12 mol/ L）干预，分别于24 h、48 h、72 h 用四甲基偶氮唑兰（MTT）法检测各组细胞增殖活性，筛选出高氧作用最佳时间及DEX 最佳工作浓度；设空气组、高氧组、高氧＋ DEX 组（DEX 浓度为10-9 mol/ L），48 h 后荧光定量 PCR 检测FGF-1、FGF-2、IL-6 mRNA 的表达。结果与空气组相比，各时间点高氧组细胞增殖活性均下降，48 h、72 h 差异均有统计学意义（P 均﹤0.05）。与高氧组相比，高氧＋ DEX 组细胞增殖活性均增高，并随 DEX 浓度降低细胞增殖活性逐渐增高，10-9 mol/ L 出现峰值，之后随着 DEX 浓度降低细胞增殖活性下降。因此，选择高氧48 h、10-9 mol/ L 的 DEX 作为后续实验条件；培养48 h，与空气组相比，高氧组 FGF-1 mRNA 下调，FGF-2、IL-6 mRNA 上调，差异有统计学意义（ P ﹤0.01）。与高氧组相比，高氧＋ DEX 组 FGF-1 mRNA 上调，FGF-2、IL-6 mRNA 下调，差异有统计学意义（P ﹤0.05）。结论950 mL/ L 的高氧刺激48 h 可制造较好的细胞损伤模型， DEX 可保护高氧所致的细胞损伤，10-9 mol/ L 为最佳浓度，DEX 上调 FGF-1 mRNA、下调 FGF-2 mRNA 可能是DEX 保护高氧性细胞损伤的机制之一。

Objective To explore the effect of Dexamethasone（DEX）on the proliferation and the expression of fibroblast growth factor（FGF）- 1,FGF - 2 and interleukin - 6（IL - 6）mRNA in hyperoxia - exposed human em-bryo lung fibroblasts（MRC - 5）. Methods High oxygen volume fraction of 950 mL/ L was used to establish hyperoxia -damaged cell models,then treated with different concentrations of DEX（10 - 4 ,10 - 6 ,10 - 8 ,10 - 9 ,10 - 10 ,10 - 11 ,10 - 12 mol/ L）,respectively. The proliferation activity of the cells was evaluated by methyl thiazolyl tetrazolium（MTT）at 24 h,48 h,72 h,and the optimal hyperoxia - exposed time and concentration of DEX were chosen;then they were divided into air group,hyperoxia group and hyperoxia ＋ DEX group. The mRNA expressions of FGF - 1,FGF - 2 and IL - 6 were detected by quantitative real - time PCR at 48 h. Results Cell proliferation activity of the hyperoxia group was lower than that of the air group and there were significant differences at 48 h and 72 h（all P ﹤ 0. 05）. Compared with the hyperoxia group,cell proliferation activity of the hyperoxia ＋ DEX group increased with the concentration of DEX decreasing,reaching the peak at 10 - 9 mol/ L,and then gradually decreased with the concentration of DEX decreasing. Cells were cultured for 48 h,compared with the air group,the level of FGF - 1 mRNA was lower,FGF - 2 and IL - 6 mRNA were higher in the hyperoxia group（P ﹤ 0. 05）. Compared with hyperoxia group,the level of FGF - 1 mRNA was higher,FGF - 2 and IL - 6 mRNA were lower in hyperoxia ＋ DEX group（P ﹤ 0. 05）. Conclusions Exposure to high oxygen volume fraction of 950 mL/ L for 48 h can cultivate optimal hyperoxia - damaged cell models,and DEX can protect the cell from hyperoxia injury and 10 - 9 mol/ L was the optimal concentration. Enhanced the expression of FGF - 1 mRNA and inhibited expression of FGF - 2 mRNA may be one of the mechanism that DEX protects the cells from hyperoxia injury.