Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders....Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.展开更多
目的探讨DLX2基因在小鼠前脑神经干细胞的增殖、迁移及向多巴胺能神经元分化过程中的作用及意义。方法在小鼠胚胎16d(E16)、生后1d(P1),7d(P7)、21d(P21)4个时间点,分别取室管膜前下区(SVZa)、嘴侧迁移流(RMS)及嗅脑(O B)3个部位,应用SY...目的探讨DLX2基因在小鼠前脑神经干细胞的增殖、迁移及向多巴胺能神经元分化过程中的作用及意义。方法在小鼠胚胎16d(E16)、生后1d(P1),7d(P7)、21d(P21)4个时间点,分别取室管膜前下区(SVZa)、嘴侧迁移流(RMS)及嗅脑(O B)3个部位,应用SYBR Green I实时相对定量荧光逆转录聚合酶链反应(RT-PCR)技术检测DLX2基因在小鼠前脑中的表达情况,以DLX2基因相对表达值(Ratio)值大于1.4为差异表达。结果从部位看,OB区E16的表达较其他3个时间点低,RMS区P21的表达较其他3个时间点低,SVZa区E16及P1的表达较P7及P21高。从时间点看,在E16时间点3个部位的表达无差异,另3个时间点中OB较RMS及SVZa高表达。结论DLX2参与了小鼠前脑中神经干细胞的增殖、迁移及分化过程,其关系具有时间及部位特异性。展开更多
The first branchial arch malformation(FBAM) is a rare congenital defect associated with anomalous development of the first and second branchial arches.Cause of FBAM still remains unknown,and is thought in most cases t...The first branchial arch malformation(FBAM) is a rare congenital defect associated with anomalous development of the first and second branchial arches.Cause of FBAM still remains unknown,and is thought in most cases to be multifactorial,involving both genetic and enviromental factors.Dlx2 as a member of the Dlx homeobox gene family,plays a crucial role in the development of the first branchial arch.The tissues regulated mainly by Dlx2 are coincident with the tissues mainly involved in FBAM.Dlx2 over-expression generated by electroporation transfection can disturb the migration and differentiation of cranial neural crest cells(CNCCs),which migrate to the branchial arches and in turn give rise to much of the facial skeleton and connective tissues.Furthermore,Dlx2 over-expression can be found in the first branchial arch spontaneous mutant mice.So we hypothesize that Dlx2 over-expression mutation causes FBAM due to an increase in cell-cell adhesion and inhibiting the migration of CNCC to the first branchial arch in the early stage,or migrating to an incorrect position and can't differentiate into normal tissues.What an exact role of Dlx2 over-expression in FBAM remains to be investigated and Dlx2 over-expression transgenic mouse will be a nice model for further research in FBAM.展开更多
基金supported by the Key Project of Guangzhou City,No.202206060002Science and Technology Project of Guangdong Province,No.2018B030332001Guangdong Provincial Pearl River Project,No.2021ZT09Y552 (all to GC)。
文摘Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.
文摘目的探讨DLX2基因在小鼠前脑神经干细胞的增殖、迁移及向多巴胺能神经元分化过程中的作用及意义。方法在小鼠胚胎16d(E16)、生后1d(P1),7d(P7)、21d(P21)4个时间点,分别取室管膜前下区(SVZa)、嘴侧迁移流(RMS)及嗅脑(O B)3个部位,应用SYBR Green I实时相对定量荧光逆转录聚合酶链反应(RT-PCR)技术检测DLX2基因在小鼠前脑中的表达情况,以DLX2基因相对表达值(Ratio)值大于1.4为差异表达。结果从部位看,OB区E16的表达较其他3个时间点低,RMS区P21的表达较其他3个时间点低,SVZa区E16及P1的表达较P7及P21高。从时间点看,在E16时间点3个部位的表达无差异,另3个时间点中OB较RMS及SVZa高表达。结论DLX2参与了小鼠前脑中神经干细胞的增殖、迁移及分化过程,其关系具有时间及部位特异性。
文摘The first branchial arch malformation(FBAM) is a rare congenital defect associated with anomalous development of the first and second branchial arches.Cause of FBAM still remains unknown,and is thought in most cases to be multifactorial,involving both genetic and enviromental factors.Dlx2 as a member of the Dlx homeobox gene family,plays a crucial role in the development of the first branchial arch.The tissues regulated mainly by Dlx2 are coincident with the tissues mainly involved in FBAM.Dlx2 over-expression generated by electroporation transfection can disturb the migration and differentiation of cranial neural crest cells(CNCCs),which migrate to the branchial arches and in turn give rise to much of the facial skeleton and connective tissues.Furthermore,Dlx2 over-expression can be found in the first branchial arch spontaneous mutant mice.So we hypothesize that Dlx2 over-expression mutation causes FBAM due to an increase in cell-cell adhesion and inhibiting the migration of CNCC to the first branchial arch in the early stage,or migrating to an incorrect position and can't differentiate into normal tissues.What an exact role of Dlx2 over-expression in FBAM remains to be investigated and Dlx2 over-expression transgenic mouse will be a nice model for further research in FBAM.
