VEGF在人胚胎干细胞向神经元分化中作用的研究

目的观察血管内皮生长因子（vascular endothelial growth factor，VEGF）在人胚胎干细胞分化为神经元过程中是否发挥作用及相关机制。方法人胚胎干细胞经拟胚体向神经元分化，分为3组：A组为常规诱导组，B组为常规诱导＋VEGF（10ng／mL）作用组，C组为常规诱导＋VEGF（10ng／mL）＋VEGFR2／Fc嵌合体（10ng／mL）作用组；用RT-PCR、免疫荧光法检测各阶段细胞标志物，计算并用流式细胞仪检测各组不同阶段细胞阳性率。结果用RT-PCR分别检测到OCT4、Nestin、MAP2表达；免疫荧光法检测显示B组产生神经干细胞、分化为神经元的阳性率明显高于A、C两组，差异有统计学意义（P〈0．01），A、C两组之间无显著性差异（P〉0．05）；流式细胞仪检测与免疫荧光法相似。结论人胚胎干细胞体外分化过程中血管内皮生长因子通过血管内皮生长因子受体2来促进神经干细胞增殖及向神经元分化。

Effect of VEGF on Neural Differentiation of Human Embryonic Stem Cells in vitro

Objective To observe the effect of VEGF on neural differentiation of human embryonic stem cells（hESCs） in vitro. Methods After embryonic body formation, hESCs were differentiated into neural cells through selection and expansion procedures, hESCs were divided into three groups： group A, routine induction; group B, routine induction ＋ 10 ng/mL VEGF treated and group C, routine induction ＋ 10 ng/mL VEGF ＋ 10 ng/mL VEGFR2/Fc treated. The cellular morphology was observed by contrast phase microscope. The markers of every stage of induction were detected through RT-PCR. Nestin and MAP2 expressing cells were detected via immunofluorescence method. The percentages of the imunostaining positive cells were determined by flow cytometer（FCM）. Results OCT4.Nestin and MAP2 were detected by RT-PCR. The percentage of Nestin and MAP2 positive cells in group B were much higher than in group A and group C（P〈0. 01 ）. There was no difference between group A and group C（P〈0. 05）. The results of FCM were roughly similar. Conclusions VEGF, via VEGFR 2, stimulates the neural cells proliferation and differentiation of human embryonic stem cells in vitro.