红细胞生成素基因修饰的间充质干细胞条件培养基促进人胚胎干细胞向造血细胞分化

本研究探讨EPO基因修饰的间充质干细胞条件培养液对人胚胎干细胞向造血细胞诱导分化的影响。通过重组慢病毒系统感染人间充质干细胞（mesenchymal stem cells，MSC），建立能够稳定高效表达红细胞生成素（erythropoietin，EPO）的细胞株EPO／MSC。用EB培养液诱导人胚胎干细胞形成拟胚体，然后用EPO／MSC条件培养液处理拟胚体细胞；通过免疫荧光、集落形成实验和RT—PCR检测等方法对诱导的细胞进行了相关鉴定。结果表明：EPO／MSC体外能够稳定表达EPO。条件培养液诱导生成的细胞表达造血干／祖细胞抗原CD34和相关造血基因，可产生不同的造血集落，且明显高于对照组。结论：EPO基因修饰的间充质干细胞条件培养液能显著促进人胚胎干细胞向造血细胞分化。

Erythropoietin Gene-Modified Conditioned Medium of Human Mesenchymal Cells Promotes Hematopoietic Development from Human Embryonic Stem Cells

The study was aimed to investigate the effect of deriving hematopoietic cells from human embryonic stem cells （hESCs） by the erythropoietin gene-modified conditioned medium of human mesenchymal cells. The mesenchymal stern cells （MSCs） steadily expressing EPO were established by lentiviral system. The expression of exogenous EPO was detected by RT-PCR and Western blot. After suspension culture, hESCs developed into embryonic bodies （EBs）. Then the EB cells were cultured in conditional medium. The hESCs-derived hematopoietic cells were analyzed by immunofluorescence, CFU assay and RT-PCR. The results indicated that the exogenous EPO successfully expressed in the EPO transfected MSCs （EPO/MSCs）. The supernatant from EPO/MSCs increased CD34^＋ cell population and the expression of globin, and enhanced colony forming unit incidence. These effects were obviously higher than that of control. It is concluded that the EPO gene-modified conditioned medium of human mesenchymal cells can induce the hESCs to differentiate into hematopoietic cells.