中文摘要：

目的体外定向诱导大鼠骨髓间充质干细胞（Mesenchymal stem cells,MSCs）成神经分化,并探讨诱导微环境对其分化的影响及分化后的自发逆转现象。方法体外分离培养大鼠MSCs,流式细胞仪检测细胞表面标志。采用改良神经元诱导液[Modified neuronal induction media（MNM）]定向诱导MSCs,免疫荧光检测神经细胞表面标志。观察胎牛血清（FBS）浓度、细胞密度、MNM剂量、新鲜与使用过的MNM等不同诱导微环境对MSCs成神经分化的影响。结果 MSCs经MNM诱导后,6h即可见尼氏体,表达神经元特异性表面标志神经元特异性烯醇化酶（NSE）、巢蛋白（Nestin）和微管相关蛋白-2（MAP-2）。随着诱导微环境的改变,MSCs成神经分化率及神经元表面标志表达亦发生改变,且分化后的神经元样细胞可自发逆转。结论 MSCs能够在MNM微环境中定向成神经分化,但诱导微环境的改变可以从量和质两个层面影响MSCs定向分化。

英文摘要：

Objective To induce the differentiation of rat bone marrow mesenchymal stem cells（MSCs）into neural-like cells in vitro and investigate the effect of micro-environment for induction on the differentiation as well as spontaneous dedifferentiation of differentiated MSCs.Methods Rat MSCs were isolated and cultured in vitro,and determined for surface markers by flow cytometry,then induced with modified neuronal induction medium（MNM）and determined for the surface markers of neurocytes by IFA.The effects of micro-environment for induction,such as FBS concentration,MNM dosage,fresh and used MNM,on the neuronal differentiation of MSCs were observed.Results Nissl bodies as well as neural specific surface markers including neuron-specific enolase（NSE）,nestin and microtubule-associated protein-2（MAP-2）were observed in the MSCs 6 h after induction with MNM.The neuronal differentiation rate of MSCs and the expressions of neural specific surface markers changed with the change of micro-environment for induction,and the neural-like cells could be dedifferentiated spontaneously back into MSC-like cells.Conclusions MSCs could be differentiated into neural-like cells under induction of MNM,however,the change of micro-environment for induction influenced the differentiation of MSCs in both quality and quantity.