Regenerating functional new neurons in the adult mammalian central nervous system has been proven to be very challenging due to the inability of neurons to divide and repopulate themselves after neuronal loss.Glial ce...Regenerating functional new neurons in the adult mammalian central nervous system has been proven to be very challenging due to the inability of neurons to divide and repopulate themselves after neuronal loss.Glial cells,on the other hand,can divide and repopulate themselves under injury or diseased conditions.We have previously reported that ectopic expression of NeuroD1 in dividing glial cells can directly convert them into neurons.Here,using astrocytic lineage-tracing reporter mice(Aldh1l1-CreERT2 mice crossing with Ai14 mice),we demonstrate that lineage-traced astrocytes can be successfully converted into NeuNpositive neurons after expressing NeuroD1 through adeno-associated viruses.Retroviral expression of NeuroD1 further confirms that dividing glial cells can be converted into neurons.Importantly,we demonstrate that for in vivo cell conversion study,using a safe level of adeno-associated virus dosage(10^10–10^12 gc/mL,1μL)in the rodent brain is critical to avoid artifacts caused by toxic dosage,such as that used in a recent bioRxiv study(2×10^13 gc/mL,1μL,mouse cortex).For therapeutic purpose under injury or diseased conditions,or for non-human primate studies,adeno-associated virus dosage needs to be optimized through a series of dose-finding experiments.Moreover,for future in vivo gliato-neuron conversion studies,we recommend that the adeno-associated virus results are further verified with retroviruses that mainly express transgenes in dividing glial cells in order to draw solid conclusions.The study was approved by the Laboratory Animal Ethics Committee of Jinan University,China(approval No.IACUC-20180330-06)on March 30,2018.展开更多
Root stem cell niche(SCN)consists of a quiescent center(QC)and surrounding stem cells.Disrupted symplastic communication leads to loss of stemness in the whole SCN.Several SCN regulators were reported to move between ...Root stem cell niche(SCN)consists of a quiescent center(QC)and surrounding stem cells.Disrupted symplastic communication leads to loss of stemness in the whole SCN.Several SCN regulators were reported to move between cells for SCN main-tenance.However,single mutant of these regulators is insu?cient to abolish QC stemness despite the high differentiation rate in surrounding stem cells.To dis-sect the mechanism behind such distinct stemness in SCN,we combined the mis-expression strategy with pWOX5:icals3m system in which QC is symplastically isolated.We found the starch accumulation in QC could be synergistically repressed by WUSCHEL-RE-LATED HOMEOBOX 5(WOX5),SHORT-ROOT(SHR),SCARCROW(SCR),and PLETHORA(PLT).Like PLTs,other core regulators also exhibited dimorphicfunctions by inhibiting differentiation at a higher dose while promoting cell division at a low protein level.Being located in the center of the intersected ex-pression zones,QC cells receive the highest level of core regulators,forming the most robust stemness within SCN.WUSCHEL-RELATED HOMEOBOX 5 was su?cient to activate PLT1/2 expression,contributing to the QC-enriched PLTs.Our results provide ex-perimental evidence supporting the long-standing hypothesis that the combination of spatial ex-pression,synergistic function and dosage effect of core regulators result in spatially distinct stemness in SCN.展开更多
基金This study was supported by the National Natural Science Foundation of China(No.U1801681,to GC and No.31970906,to WL)Guangdong Science and Technology Department(‘Key technologies for treatment of brain disorders’,No.2018B030332001,to GC)+2 种基金the Natural Science Foundation of Guangdong Province of China(No.2020A1515011079,to WL and No.2020A1515010854,to QW)the internal funding from Jinan University(No.21616110,to GC)the Young Scientists Fund of the National Natural Science Foundation of China(No.31701291,to WL).
文摘Regenerating functional new neurons in the adult mammalian central nervous system has been proven to be very challenging due to the inability of neurons to divide and repopulate themselves after neuronal loss.Glial cells,on the other hand,can divide and repopulate themselves under injury or diseased conditions.We have previously reported that ectopic expression of NeuroD1 in dividing glial cells can directly convert them into neurons.Here,using astrocytic lineage-tracing reporter mice(Aldh1l1-CreERT2 mice crossing with Ai14 mice),we demonstrate that lineage-traced astrocytes can be successfully converted into NeuNpositive neurons after expressing NeuroD1 through adeno-associated viruses.Retroviral expression of NeuroD1 further confirms that dividing glial cells can be converted into neurons.Importantly,we demonstrate that for in vivo cell conversion study,using a safe level of adeno-associated virus dosage(10^10–10^12 gc/mL,1μL)in the rodent brain is critical to avoid artifacts caused by toxic dosage,such as that used in a recent bioRxiv study(2×10^13 gc/mL,1μL,mouse cortex).For therapeutic purpose under injury or diseased conditions,or for non-human primate studies,adeno-associated virus dosage needs to be optimized through a series of dose-finding experiments.Moreover,for future in vivo gliato-neuron conversion studies,we recommend that the adeno-associated virus results are further verified with retroviruses that mainly express transgenes in dividing glial cells in order to draw solid conclusions.The study was approved by the Laboratory Animal Ethics Committee of Jinan University,China(approval No.IACUC-20180330-06)on March 30,2018.
基金This work is supported by the National Key Research and Development Program of China(2016YFD0100700)the grant from the National Natural Science Foundation of China(31722006)Key Research Program of Fujian Province(2018NZ0002)to S.W.
文摘Root stem cell niche(SCN)consists of a quiescent center(QC)and surrounding stem cells.Disrupted symplastic communication leads to loss of stemness in the whole SCN.Several SCN regulators were reported to move between cells for SCN main-tenance.However,single mutant of these regulators is insu?cient to abolish QC stemness despite the high differentiation rate in surrounding stem cells.To dis-sect the mechanism behind such distinct stemness in SCN,we combined the mis-expression strategy with pWOX5:icals3m system in which QC is symplastically isolated.We found the starch accumulation in QC could be synergistically repressed by WUSCHEL-RE-LATED HOMEOBOX 5(WOX5),SHORT-ROOT(SHR),SCARCROW(SCR),and PLETHORA(PLT).Like PLTs,other core regulators also exhibited dimorphicfunctions by inhibiting differentiation at a higher dose while promoting cell division at a low protein level.Being located in the center of the intersected ex-pression zones,QC cells receive the highest level of core regulators,forming the most robust stemness within SCN.WUSCHEL-RELATED HOMEOBOX 5 was su?cient to activate PLT1/2 expression,contributing to the QC-enriched PLTs.Our results provide ex-perimental evidence supporting the long-standing hypothesis that the combination of spatial ex-pression,synergistic function and dosage effect of core regulators result in spatially distinct stemness in SCN.