转录因子组合诱导大鼠星形胶质细胞转分化为多巴胺能神经元

Transcription factors combination induces transdifferentiation of rat astrocytes into dopaminergic neurons

目的:探究不同转录因子组合诱导大鼠海马星形胶质细胞(AS)转分化为多巴胺(DA)能神经元表型的效率。方法:构建表达特定的转录因子的重组慢病毒,包括MLN组合(Mash1、Lmx1a和Nurr1)、MNNg组合(Mash1、Nurr1和Ngn2)、LNNg组合(Lmx1a、Nurr1和Ngn2)以及MLNg组合(Mash1、Lmx1a和Ngn2),分别感染大鼠AS,利用免疫荧光染色检测细胞中神经元微管蛋白(Tuj1)、酪氨酸羟化酶(TH)、微管相关蛋白2(MAP2)、多巴脱羧酶(DDC)和突触素1(SYN1)的表达。结果:成功构建出携带有不同转录因子组合的重组慢病毒载体,且能够在细胞内正常表达。在慢病毒感染海马AS第14和28 d,MLN组合分别诱导出20%和60%左右的TH阳性DA能神经元,第28 d时LNNg组合诱导出20%左右TH阳性的DA能神经元,MLNg和MNNg组合仅诱导出Tuj1阳性神经元,进一步染色发现MLN组合能够诱导出多种成熟神经元标记物MAP2、DDC及SYN1表达。结论:转录因子间的协同作用是DA能神经元诱导成功的重要条件,MNNg、LNNg和MLNg组合未能有效诱导大鼠海马AS表达DA能神经元表型,MLN组合仍是高效诱导DA能神经元表型的转录因子组合。

Objective:To explore the efficiency of different transcription factor combinations to induce the transdifferentiation of rat hippocampal astrocytes(AS)into dopaminergic(DA)neuron phenotype.Methods:Recombinant lentiviral vectors were constructed to express specific transcription factors,including classic MLN combinations(Mash1,Lmx1a,and Nurr1),MNNg combination(Mash1,Nurr1,and Ngn2),LNNg combination(Lmx1a,Nurr1,and Ngn2),and MLNg combination(Mash1,Lmx1a,and Ngn2).The rat hippocampal AS were infected using above recombinant lentivirus.Neuronal classⅢβ-tubulin(Tuj1),tyrosine hydroxylase(TH),microtubule-associated protein 2(MAP2),dopa decarboxylase(DDC)and synaptophysin 1(SYN1)were detected by immunofluorescence staining.Results:Recombinant lentiviral vectors carrying different combinations of transcription factors were successfully constructed and could be expressed normally in cells.On the 14th and 28th days of lentiviral infection of hippocampal AS,the MLN combination induced about 20%and 60%of TH-positive DA neurons,respectively.On the 28th day,the LNNg combination induced about 20%of TH-positive DA neurons.The MLNg combination and MNNg combination only induced Tuj1-positive neurons,and further staining showed that the MLN combination could induce more MAP2,DDC,and SYN1 expression.Conclusion:The synergy between transcription factors is an important condition for the successful induction of DA neurons.The MNNg combination,LNNg combination,and MLNg combination failed to effectively induce rat hippocampal AS to express the DA phenotype,and the MLN combination is still a combination of transcription factors that efficiently induces the DA phenotype.