不同低氧浓度预处理对人脐带间充质干细胞抗凋亡能力的影响

Influence of hypoxic preconditioning at different oxygen concentration on anti-apoptosis ability of human umbilical cord-derived mesenchymal stem cells

目的探讨人脐带间充质干细胞经低氧预处理后抗凋亡能力的改变。方法分离、培养人脐带间充质干细胞,低氧预处理24 h。根据预处理氧浓度分5组:1%O2组,3%O2组,5%O2组,10%O2组和对照组(21%O2)。实时定量PCR检测凋亡相关基因Bax和Bcl-2的表达。去血清培养基低氧环境诱导干细胞凋亡,Annexin V/PI流式法检测细胞凋亡百分比。实验数据采用单因素方差分析进行统计分析。结果促凋亡基因Bax在1%O2组、3%O2组表达量(0.31±0.05,0.36±0.17)显著低于对照组和10%O2组(1,1.07±0.15),P<0.01。抗凋亡基因Bcl-2在所有低氧处理组表达量(10.02±1.63,19.92±4.33,16.48±2.77,15.02±3.49)均显著高于对照组,P<0.01;在1%O2组表达量显著低于3%O2组(P<0.01)。所有低氧预处理组干细胞与阳性对照组(21%O2组)相比,早期、晚期及总凋亡数量均显著减少(P<0.01),其余各组间比较差异无统计学意义。结论对人脐带间充质干细胞进行适当低氧预处理,可以降低促凋亡基因表达,提高抗凋亡基因表达,能提高干细胞抗凋亡能力。

Objective To investigate the change of anti-apoptosis ability of human umbilical cord-derived mesenchymal stem cells（ h UC-MSCs） after the hypoxic preconditioning. Methods The h UC-MSCs were isolated and cultured,and exposed to the hypoxic condition for 24 h. The h UC-MSCs were divided into 5 groups according to the preconditioning oxygen concentration： 1% O2,3% O2,5% O2,10% O2 and control group（21% O2）. Real-time PCR was performed to investigate the expression of Bax and Bcl-2 gene. Apoptosis of h UC-MSCs was induced and were detected by Annexin V-FITC /PI test. Results The expression of Bax gene in 1% O2 and 3% O2group（0. 31 ± 0. 05,0. 36 ± 0. 17） were down-regulated significantly when compared with the control and 10% O2groups（1,1. 07 ± 0. 15）,P 〈0. 01;The expression of Bcl-2gene in 1% O2,3% O2,5% O2 and 10% O2（10. 02 ± 1. 63,19. 92 ± 4. 33,16. 48 ± 2. 77,15. 02 ± 3. 49）were up-regulated significantly when compared with the control,P 〈0. 01;The percentage of apoptotic cells in all the hypoxic preconditioned group was decreased significantly compared to the positive control（ P 〈0. 01）. Conclusion Hypoxic preconditioning of h UC-MSCs can enhance their ability of anti-apoptosis via regulating the expression of apoptosis-related genes.