氧浓度对人胎盘间充质干细胞生物学特性的影响

Effect of different oxygen concentration on the biological characteristics of human placenta derived mesenchymal stem cells

目的：比较不同氧浓度对人胎盘间充质干细胞生物学特性的影响。方法组织块培养法分离人胎盘间充质干细胞pMSCs，并利用流式细胞技术进行表面标志鉴定。将第3代pMSCs分别培养于常氧（21％O2）及不同浓度的低氧（5％O2、3％O2、1％O2、0．5％O2）环境中，观察各组细胞形态，MTT检测细胞增殖情况，划痕实验检测细胞迁移能力，ELISA检测细胞VEGF分泌表达量情况。结果成功从人胎盘组织分离出间充质干细胞pMSCs，阳性表达CD29、CD44，阴性表达CD31、CD34、CD45、HLA－DR。低氧培养的pMSCs形态均一，细胞伸展为长梭形，漩涡状排列明显。与常氧组相比，一定范围内低氧（5％O2～1％O2）培养的pMSCs增殖、迁移增快，分泌VEGF增多，氧浓度越低，变化越明显。过低氧浓度（0．5％O2）培养的pMSCs增殖减慢，分泌VEGF减少。结论一定范围内的低氧可促进pMSCs增殖、迁移及分泌VEGF，氧浓度越低，促进作用越明显。而过低氧浓度则产生抑制作用。

Objective To compare the effects of different oxygen concentrations on the biological characteristics of human placenta derived mesenchymal stem cells.Methods Human placenta derived mesenchymal stem cells were isolated by tis-sue culture method and their surface markers were identified by flow cytometry.The third generation of pMSCs were cul-tured in the environment of normoxia （21%O2 ） and hypoxia of different concentrations （5%O2 , 3%O2 , 1%O2 , 0.5%O2 ） .The morphologic changes of pMSCs were detected by inverted phase contrast microscope.The proliferation of pMSCs were examined by methyl-tetrazolium （ MTT） assay.The migration of pMSCs were analyzed by scratch assay and the VEGF secretion was detected by ELISA.Results Human placenta derived mesenchymal stem cells were successfully isola-ted.They expressed CD29, CD44 positively but CD31,CD34,CD45,HLA-DR negatively.The morphology of pMSCs cul-tured in hypoxia are uniform, long spindle shapes and whorls significantly.Compared with normoxia group, the prolifera-tion, migration and VEGF secretion of pMSCs cultured in hypoxia within a certain range （5%O2 -1%O2 ） increased.The lower the oxygen concentration, the more obvious the changes were.However, the proliferation and VEGF secretion of pM-SCs cultured in low oxygen concentration （0.5%O2 ） decreased.Conclusions Hypoxia within a certain range can promote proliferation, migration and VEGF secretion of pMSCs.The lower the oxygen concentration, the more obvious the promoting effect is.But too low oxygen concentration produces inhibition effect.