胰岛素样生长因子-1对高氧诱导的A549细胞凋亡的影响

Effect of insulin-like growth factor-1 on hyperoxia-induced apoptosis in A549 cells

摘要:

目的：胰岛素样生长因子-1(IGF-1）具有促进细胞分化、抑制细胞凋亡等多种生物学活性。该研究旨在探讨IGF-1对高氧诱导的A549细胞凋亡的影响及其抗凋亡机制。方法：将传代培养的A549细胞暴露于高氧环境，并以不同浓度IGF-1（1、10、100 ng/mL）干预48 h，采用四甲基偶氮唑蓝(MTT)法检测细胞存活率，Annexin V-FITC／PI双染流式细胞术检测细胞凋亡变化，同时用流式细胞仪检测凋亡调控相关蛋白（Bax、Bcl-2）表达水平的变化。结果：高氧组细胞存活率为（51±3）%，IGF-1干预组细胞存活率随着IGF-1药物浓度的递增逐渐升高，中、高剂量IGF-1干预组细胞存活率分别为（64±3）%和（88±4）%，与高氧组相比，差异均有统计学意义(P<0.05)。高氧组A549细胞凋亡率为(38.3±5.4)%，较空气组（2.4±0.9）%明显增多；高氧组Bcl-2的蛋白表达水平为（72±5）%，较空气组（91±4）%明显下降；高氧组Bax的表达水平为（54±6）%，较空气组（3±2）%明显升高，差异均有统计学意义（P<0.05)。与高氧组比较，IGF-1干预组细胞凋亡率随着药物浓度的增加逐渐下降，分别为（16.1±4.7）%、（9.2±2.8）%和（6.9±2.5）%，差异有统计学意义（P<0.05)。与高氧组比较，IGF-1干预组细胞Bcl-2的表达逐渐增高，分别为（79±4）%、（94±4）%和（100±5）%，而Bax的表达逐渐下降，分别为（26±4）%、（5±2）%和（4±2）%，差异均有统计学意义（P<0.05)。结论：高氧明显抑制A549细胞的增殖，促进其凋亡；IGF-1具有促进A549细胞增殖，通过调节凋亡调控蛋白Bcl2和Bax表达，抑制高氧诱导的A549细胞凋亡的作用。

Abstract:

OBJECTIVE: To investigate the effect of insulin-like growth factor-1 (IGF-1), which can promote cell differentiation and inhibit cell apoptosis, on hyperoxia-induced apoptosis in A549 cells and its anti-apoptotic mechanism. METHODS: A549 cells were sub-cultured, exposed to hyperoxic conditions and were then treated with different concentrations of IGF-1 (1, 10, and 100 ng/mL) for 48 hours. Cell viability was measured by MTT assay. Cell apoptosis was evaluated by Annexin V-FITC/PI double-staining flow cytometry. Expression levels of Bax and Bcl-2 were measured by flow cytometry. RESULTS: The middle-dose and high-dose IGF-1 intervention groups had higher cell viabilities than the hyperoxic exposure group ［(64±3）% and (88±4)% vs (51±3)%; P<0.05］. Compared with the air control group, the hyperoxic exposure group had a significantly higher apoptotic rate ［(38.3±5.4)% vs (2.4±0.9）%; P<0.05］, a significantly lower expression level of Bcl-2 ［(72±5)% vs (91±4)%; P<0.05］, and a significantly higher expression level of Bax ［(54±6)% vs (3±2)%; P<0.05］. Compared with the hyperoxic exposure group, the low-dose, middle-dose, and high-dose IGF-1 intervention groups had significantly lower apoptotic rates ［(16.1±4.7)%, (9.2±2.8)%, and (6.9±2.5)% vs (38.3±5.4)%; P<0.05］, significantly higher expression level of Bcl-2 ［(79±4)%, (94±4)%, and (100±5)% vs (72±5)%; P<0.05］, and significantly lower expression level of Bax ［(26±4)%, (5±2)%, and (4±2)% vs (54±6)%; P<0.05］. CONCLUSIONS: Hyperoxia significantly inhibits proliferation and promotes apoptosis in A549 cells. IGF-1 may promote cell proliferation and inhibit hyperoxia-induced apoptosis in A549 cells by regulating the expression of Bcl-2 and Bax.