骨髓间充质干细胞向神经细胞分化过程中Tau蛋白表达量的变化

Change of Tau protein during mesenchymal stem cells differentiating into neural cells

目的:观察体外诱导新生豚鼠骨髓间充质干细胞(MSCs)分化为神经细胞过程中神经细胞Tau蛋白表达量的改变。方法:用H-DMEM培养基加胎牛血清(H-DMEM/FBS)体外培养新生豚鼠MSCs并传代扩增;分为实验组和对照组,实验组使用含细胞因子的培养基诱导MSCs向神经细胞分化,对照组加入不含细胞因子的培养基;用倒置显微镜观察2组细胞形态学改变;用ELISA法定量分析诱导分化第1、4、7、10天和第14天Tau蛋白含量的变化;免疫细胞化学法检测第14天神经元特异性烯醇化酶(NSE)和Tau蛋白的表达。结果:在细胞因子作用下豚鼠骨髓MSCs逐渐向神经细胞分化,在诱导第10天时形态上有典型神经细胞样改变;ELISA法检测发现Tau蛋白在诱导分化早期含量很低,随着诱导分化时间的延长,Tau蛋白含量逐渐升高,第10天趋于稳定,至第14天时Tau蛋白含量无明显增加;免疫细胞化学法可检测到NSE和Tau蛋白抗体阳性细胞。结论:间充质干细胞向神经细胞分化过程中Tau蛋白表达量逐渐升高,其稳定表达可能是神经细胞分化完成或成熟的标志之一。

Aim： To observe the expression changes of Tau protein during newborn guinea pig bone-marrow mesenchymal stem cells （MSCs） differentiating into neural cells induced by cytokines in vitro. Methods：Newborn guinea pigg MSCs were purified and proliferated in H-DMEM/FBS media in vitro. Conditioned media containing EGF and bFGF was applied for differentiation of MSCs into neural cells. During differentiation process Tau protein content was determined by ELISA assay on the 1st day,4th day,Tth day,10th day,and 14th day,and on the 14th day the neural cell specific marker NSE and Tau protein were determined by immunocytochemistry. Results： Induced by cytokines,MSCs began to display neuron-like shape on the 10th day. Tau protein expression was very low at the beginning of induction and increased till the 10th day when Tau protein reached a steady level. NSE and Tau were positive on the 14th day by immunocytochemistry. Conclusion： Tau protein is a useful marker to judge when MSCs differentiate into mature neural cells.