Mesenchymal stem cell(MSC)-based therapy has emerged as a promising treatment for spinal cord injury(SCI),but improving the neurogenic potential of MSCs remains a challenge.Mixed lineage leukemia 1(MLL1),an H3K4me3 me...Mesenchymal stem cell(MSC)-based therapy has emerged as a promising treatment for spinal cord injury(SCI),but improving the neurogenic potential of MSCs remains a challenge.Mixed lineage leukemia 1(MLL1),an H3K4me3 methyltransferases,plays a critical role in regulating lineage-specific gene expression and influences neurogenesis.In this study,we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla(SCAPs).We examined the expression of neural markers,and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells,immunofluorescence staining,and a SCI model.We employed a coimmunoprecipitation(Co-IP)assay,real-time RT-PCR,microarray analysis,and chromatin immunoprecipitation(ChIP)assay to investigate the molecular mechanism.The results showed that MLL1 knock-down increased the expression of neural markers,including neurogenic differentiation factor(NeuroD),neural cell adhesion molecule(NCAM),tyrosine hydroxylase(TH),βIII-tubulin and Nestin,and promoted neuron-like cell formation in SCAPs.In vivo,a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model.MLL1 can combine with WD repeat domain 5(WDR5)and WDR5 inhibit the expression of neural markers in SCAPs.MLL1 regulates Hairy and enhancer of split 1(HES1)expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5.Additionally,HES1 enhances the expression of neural markers in SCAPs.Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1.These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.展开更多
MLL1 is a histone H3Lys4 methyltransferase and forms a complex with WDR5 and other components.It plays important roles in developmental events,transcriptional regulation,and leukemogenesis.MLL1-fusion proteins resulti...MLL1 is a histone H3Lys4 methyltransferase and forms a complex with WDR5 and other components.It plays important roles in developmental events,transcriptional regulation,and leukemogenesis.MLL1-fusion proteins resulting from chromosomal translocations are molecular hallmarks of a special type of leukemia,which occurs in over 70% infant leukemia patients and often accompanies poor prognosis.Investigations in the past years on leukemogenesis and the MLL1-WDR5 histone H3Lys4 methyltransferase complex demonstrate that epigenetic regulation is one of the key steps in development and human diseases.展开更多
基金the Beijing Natural Science Foundation(7222075 to Z.P.F.)National Natural Science Foundation of China(82130028 to Z.P.F.)+3 种基金the National Key Research and Development Program(2022YFA1104401 to Z.P.F.)the CAMS Innovation Fund for Medical Sciences(2019-I2M-5-031 to Z.P.F.)the Innovation Research Team Project of Beijing Stomatological Hospital,Capital Medical University(No.CXTD202204 to Z.P.F.)the Young Scientist Program of Beijing Stomatological Hospital,Capital Medical University(No.YSP202113 to C.Z.).
文摘Mesenchymal stem cell(MSC)-based therapy has emerged as a promising treatment for spinal cord injury(SCI),but improving the neurogenic potential of MSCs remains a challenge.Mixed lineage leukemia 1(MLL1),an H3K4me3 methyltransferases,plays a critical role in regulating lineage-specific gene expression and influences neurogenesis.In this study,we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla(SCAPs).We examined the expression of neural markers,and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells,immunofluorescence staining,and a SCI model.We employed a coimmunoprecipitation(Co-IP)assay,real-time RT-PCR,microarray analysis,and chromatin immunoprecipitation(ChIP)assay to investigate the molecular mechanism.The results showed that MLL1 knock-down increased the expression of neural markers,including neurogenic differentiation factor(NeuroD),neural cell adhesion molecule(NCAM),tyrosine hydroxylase(TH),βIII-tubulin and Nestin,and promoted neuron-like cell formation in SCAPs.In vivo,a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model.MLL1 can combine with WD repeat domain 5(WDR5)and WDR5 inhibit the expression of neural markers in SCAPs.MLL1 regulates Hairy and enhancer of split 1(HES1)expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5.Additionally,HES1 enhances the expression of neural markers in SCAPs.Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1.These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.
文摘MLL1 is a histone H3Lys4 methyltransferase and forms a complex with WDR5 and other components.It plays important roles in developmental events,transcriptional regulation,and leukemogenesis.MLL1-fusion proteins resulting from chromosomal translocations are molecular hallmarks of a special type of leukemia,which occurs in over 70% infant leukemia patients and often accompanies poor prognosis.Investigations in the past years on leukemogenesis and the MLL1-WDR5 histone H3Lys4 methyltransferase complex demonstrate that epigenetic regulation is one of the key steps in development and human diseases.
