人胚胎神经干细胞向神经元分化过程中Notch1基因的表达

目的 :探讨Notch1基因在全反式维甲酸 (ATRA)诱导人胚胎神经干细胞分化为神经元过程中的表达及其发挥的作用。方法 :用不同浓度 (0 .5、1、5和 10 μmol/L)的ATRA在体外诱导人胚胎神经干细胞 ,7d后 ,做NSE免疫荧光染色 ,计数分化为神经元的比例。用 1μmol/L的ATRA诱导人胚胎神经干细胞 ,于诱导前、诱导 3d和诱导 7d,提取细胞的总RNA ,用半定量RT PCR法检测Notch1基因的表达。结果 :与对照组相比较 ,ATRA能显著提高人胚胎神经干细胞分化为神经元的比例 (P <0 .0 1)。其中 1μmol/L的ATRA诱导人胚胎神经干细胞分化为神经元的比例最高 ,为 (2 9.2 0± 1.0 9) %。Notch1基因在ATRA诱导后表达明显下调 (P <0 .0 0 1)。结论 :ATRA能显著提高人胚胎神经干细胞分化为神经元的比例 ,Notch1基因在人胚胎神经干细胞分化为神经元的过程中表达量下调

Expression of Notch1 gene in the differentiation of the human embryonic neural stem cells to neurons

AIM:To explore the expression and role of Notch1 gene in the differentiation of the human embryonic neural stem cells to neurons induced by all-trans-retinoic-acid(ATRA). METHODS: The human embryonic neural stem cells were induced with various concentrations of ATRA(0.5, 1, 5 and 10 mumol/L) in vitro. Immunofluorescence staining was performed after seven days, and neurons were quantified by counting NSE positive cells. Then human embryonic neural stem cells were induced to differentiate with 1 mumol/L ATRA. Total RNA was extracted from the cells before inducing, induced for 3 days, and for 7 days. The expression of Notch1 gene was tested by semi-quantitative RT-PCR. RESULTS: The ratio of neural stem cells to differentiate to neurons was improved greatly by ATRA induction as compared with control group (P<0.01). 1 mumol/L ATRA was the optimal dose for induction of the human embryonic neural stem cell differentiation. The percentage of neurons induced by 1 micromol/L ATRA was (29.20+/-1.09)%. The expression of Notch1 gene decreased significantly after being treated with ATRA(P<0.001). CONCLUSION: ATRA can greatly increase the percentage of neurons in the course of inducing the human embryonic neural stem cells to differentiate. Notch1 gene is down-regulated when human embryonic neural stem cells differentiate into neurons.