干细胞向运动神经元诱导分化的特点

Characteristics of motor neuron differentiation from stem cells

目前研究证明胚胎干细胞和神经干细胞可以诱导分化为运动神经元,诱导主要方法是在培养过程中加入诱导因子,从而提高分化培养中运动神经元的分化比例。运动神经元在体外培养中发育成熟的过程与其在胚胎内发育过程类似,也有Pax6、Nkx6.1、Olig2和HB9等转录因子的参与,其中以HB9为分选标志的细胞在体外几乎完全分化为运动神经元。此外,还有其他种类的蛋白标志用到运动神经元的诱导分化鉴定中,如神经元标志MAP-2、β-tubulin-Ⅲ,胆碱能细胞标志ChAT、VAChT,许旺细胞有丝分裂原REG2,电压依赖性钙离子通道亚单位等。运动神经元诱导分化的鉴定除了上述特异性分子标志表达的检测外,还需检验分化的运动神经元是否具有功能。运动神经元功能的检测方法可分为两类,一是检测体外培养中的运动神经元是否具有功能,二是检测分化的运动神经元移植到动物体内是否也同样具有功能。干细胞诱导分化为运动神经元方法已基本成熟,但距临床应用还有很多问题需要进一步讨论,如关于运动神经元诱导分化的细胞来源、运动神经元诱导分化的效率、分化运动神经元的纯化、运动神经元的功能等。

Studies have shown that embryonic stem cells and neural stem cells could be induced to differentiate into motor neurons by adding inducing factors to the culture to improve differentiation proportion of motor neurons.The development and maturation process of motor neurons in vitro culture is similar to that in embryo,involving participation of Pax6,Nkx6.1,Olig2 and HB9.Moreover,cells with HB9 as separation mark almost differentiate into motor neurons in vitro.In addition,other types of protein marks have been used for identification of motor neuronal induced differentiation,such as neuron mark MAP-2,β-tubulin-III,cholinergic cell mark ChAT,VAChT,Schwann cell mitogen REG2,and voltage-dependent calcium ion channel 11.2 subunit.The identification of induced differentiation of motor neurons also involves detection of function of differentiated motor neurons by two methods.One method is to detect the function of in vitro cultured motor neurons,and the other is to detect the function of transplanted motor neurons in vivo.Although induced differentiation of stem cells into motor neurons becomes mature,many issues remain in clinical application,such as cell sources of induced differentiation of motor neuron,efficiency of induced differentiation,purification of differentiated motor neurons,and function of motor neurons.