Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and...Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and the ability to stimulate axon regeneration from surviving ganglion cells could provide the anatomic substrate for restoration of vision.OTX2 is a homeoprotein transcription factor expressed in the retina and previous studies showed that,in response to stress,exogenous OTX2 increases the in vitro and in vivo survival of RGCs.Here we examined and quantified the effects of OTX2 on adult RGC axon regeneration in vitro and in vivo.The results show that exogenous OTX2 stimulates the regrowth of axons from RGCs in cultures of dissociated adult retinal cells and from explants of adult retinal tissue and that RGCs respond directly to OTX2 as regrowth is observed in cultures of purified adult rat RGCs.Importantly,after nerve crush in vivo,we observed a positive effect of OTX2 on the number of regenerating axons up to the optic chiasm within 14 days post crush and a very modest level of acuity absent in control mice.The effect of OTX2 on RGC survival and regeneration is of potential interest for degenerative diseases affecting this cell type.All animal procedures were approved by the local "Comié d'éιthique en expérimentation animale n°59" and authorization n° 00702.01 delivered March 28,2014 by the French "Ministére de l'enseignement supérieur et de la recherche".展开更多
Early embryonic development is controlled by maternal factors originating from mature oocytes.The zygotic genome is activated from a transcriptionally quiescent state through a process called embryonic genome activati...Early embryonic development is controlled by maternal factors originating from mature oocytes.The zygotic genome is activated from a transcriptionally quiescent state through a process called embryonic genome activation(EGA),which involves the depletion and clearance of maternal factors.However,the mechanism by which maternal factors regulate EGA and embryonic development,particularly in humans,remains elusive.In this study,using tri-pronuclear(3PN) embryos and human embryonic stem cells(h ESCs),we demonstrated that the maternal transcription factor Orthodenticle Homeobox 2(OTX2),a paired-like homeobox gene,promotes EGA in human pre-implantation embryos.Knockdown of OTX2 through Trim-Away technology blocked embryonic development and minor EGA gene expression.Overexpression of OTX2(OTX2~(OE)) in h ESCs increased transcript products,primarily at the 2-cell embryo stage genes,including genes encoding methyltransferase of histone H3K4.OTX2~(OE) increased the level of H3K4me3 and increased the open chromatin region that co-occurs with the H3K4me3 region at the 4-cell stage in h ESCs.Based on these findings in h ESCs,we further verified that OTX2 directly induced the expression of SETD1A by binding to its promoter,leading to increased H3K4me3 levels in both h ESCs and 3PN embryos.These findings suggest that the maternal transcription factor OTX2 regulates EGA and early embryogenesis via epigenetic mechanisms.展开更多
Sall4 as one of the spalt family members contains several alternative splicing variants, which are differentially expressed and has a key role in maintaining pluripotent stem cells. However, the molecular features and...Sall4 as one of the spalt family members contains several alternative splicing variants, which are differentially expressed and has a key role in maintaining pluripotent stem cells. However, the molecular features and function of SALL4 have not been well elucidated in porcine induced pluripotent stem cells(piPSCs). In this study, we identi?ed SALL4 splice variants and found two SALL4 splicing variants through analysis of the porcine transcriptome data derived from piPSCs. SALL4 A was only detected in piPSCs but SALL4 B was globally expressed in porcine tissues and piPSCs. The level of SALL4 B was signi?cantly reduced when piPSCs differentiation occurred, however, the expression of SALL4 A was not affected, indicating that SALL4 B may be essential for the maintenance of piPSCs self-renewal. Overexpression of SALL4 A and SALL4 B in PEF cells could signi?cantly stimulated expression of endogenous pluripotent genes,when SALL4 B signi?cantly promoted OCT4 expression.Conversely, SALL4 A signi?cantly promoted KLF4 expression. Additionally, both SALL4 A and SALL4 B could repress OTX2 promoter activity in a dose-dependent manner. Conversely, OTX2 also negatively regulated SALL4 expression. These observations indicate that a negative feedback regulatory mechanism may exist between SALL4 and OTX2, which is useful for the maintenance of the self-renewal of piPSCs.展开更多
Assisted reproductive technology(ART)is associated with increased implantation failure and subsequent metabolic abnormalities in offspring,but the underlying mechanisms remain largely elusive.Here,we reveal that persi...Assisted reproductive technology(ART)is associated with increased implantation failure and subsequent metabolic abnormalities in offspring,but the underlying mechanisms remain largely elusive.Here,we reveal that persistent Wnt signaling during the peri-implantation stage may be a key obstacle to the implantation of in vitro fertilization(IVF)embryos in a mouse model.Wnt activation affects the deposition of H3K27ac and H3K27me3 on pluripotency genes and bivalent genes,respectively,leading to the abnormal naïve-primed transition and suppressing expression of Otx2 in the epiblast.Furthermore,treatment with the Wnt inhibitor IWP2 promotes the redistribution of histone modifications and gene expression of epiblast.Importantly,Wnt inhibiting significantly improves implantation and intrauterine development of IVF embryos and subsequently ameliorates offspring metabolic abnormalities.Moreover,Wnt inhibiting markedly improves human peri-implantation embryo development and facilitates the transition from a naïve pluripotency state.Our study reveals a novel mechanism underlying the prevention of IVF embryo implantation failure and metabolic disorders in offspring.展开更多
基金supported by Fovea-Pharmaceuticals,and Global Research Laboratory Program Grant 2009-00424 from the Korean Ministry of Education,Science,and Technology,HOMEOSIGN:ERC-2013-AdG n°339379 and Neuropr Otx:ANR-16-CE16-0003-02。
文摘Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and the ability to stimulate axon regeneration from surviving ganglion cells could provide the anatomic substrate for restoration of vision.OTX2 is a homeoprotein transcription factor expressed in the retina and previous studies showed that,in response to stress,exogenous OTX2 increases the in vitro and in vivo survival of RGCs.Here we examined and quantified the effects of OTX2 on adult RGC axon regeneration in vitro and in vivo.The results show that exogenous OTX2 stimulates the regrowth of axons from RGCs in cultures of dissociated adult retinal cells and from explants of adult retinal tissue and that RGCs respond directly to OTX2 as regrowth is observed in cultures of purified adult rat RGCs.Importantly,after nerve crush in vivo,we observed a positive effect of OTX2 on the number of regenerating axons up to the optic chiasm within 14 days post crush and a very modest level of acuity absent in control mice.The effect of OTX2 on RGC survival and regeneration is of potential interest for degenerative diseases affecting this cell type.All animal procedures were approved by the local "Comié d'éιthique en expérimentation animale n°59" and authorization n° 00702.01 delivered March 28,2014 by the French "Ministére de l'enseignement supérieur et de la recherche".
基金supported by grants from the National Natural Science Foundation of China (32000564,31970504)the China Postdoctoral Science Foundation (2020M682574)+1 种基金the Natural Science Foundation of Hunan Province (S2021JJQNJJ0952)the Reproductive and Genetic Hospital of the CITIC-XIANGYA project (YNXM-201909)。
文摘Early embryonic development is controlled by maternal factors originating from mature oocytes.The zygotic genome is activated from a transcriptionally quiescent state through a process called embryonic genome activation(EGA),which involves the depletion and clearance of maternal factors.However,the mechanism by which maternal factors regulate EGA and embryonic development,particularly in humans,remains elusive.In this study,using tri-pronuclear(3PN) embryos and human embryonic stem cells(h ESCs),we demonstrated that the maternal transcription factor Orthodenticle Homeobox 2(OTX2),a paired-like homeobox gene,promotes EGA in human pre-implantation embryos.Knockdown of OTX2 through Trim-Away technology blocked embryonic development and minor EGA gene expression.Overexpression of OTX2(OTX2~(OE)) in h ESCs increased transcript products,primarily at the 2-cell embryo stage genes,including genes encoding methyltransferase of histone H3K4.OTX2~(OE) increased the level of H3K4me3 and increased the open chromatin region that co-occurs with the H3K4me3 region at the 4-cell stage in h ESCs.Based on these findings in h ESCs,we further verified that OTX2 directly induced the expression of SETD1A by binding to its promoter,leading to increased H3K4me3 levels in both h ESCs and 3PN embryos.These findings suggest that the maternal transcription factor OTX2 regulates EGA and early embryogenesis via epigenetic mechanisms.
基金supported by the National Natural Science Foundation of China (31571521 and 31371505)
文摘Sall4 as one of the spalt family members contains several alternative splicing variants, which are differentially expressed and has a key role in maintaining pluripotent stem cells. However, the molecular features and function of SALL4 have not been well elucidated in porcine induced pluripotent stem cells(piPSCs). In this study, we identi?ed SALL4 splice variants and found two SALL4 splicing variants through analysis of the porcine transcriptome data derived from piPSCs. SALL4 A was only detected in piPSCs but SALL4 B was globally expressed in porcine tissues and piPSCs. The level of SALL4 B was signi?cantly reduced when piPSCs differentiation occurred, however, the expression of SALL4 A was not affected, indicating that SALL4 B may be essential for the maintenance of piPSCs self-renewal. Overexpression of SALL4 A and SALL4 B in PEF cells could signi?cantly stimulated expression of endogenous pluripotent genes,when SALL4 B signi?cantly promoted OCT4 expression.Conversely, SALL4 A signi?cantly promoted KLF4 expression. Additionally, both SALL4 A and SALL4 B could repress OTX2 promoter activity in a dose-dependent manner. Conversely, OTX2 also negatively regulated SALL4 expression. These observations indicate that a negative feedback regulatory mechanism may exist between SALL4 and OTX2, which is useful for the maintenance of the self-renewal of piPSCs.
基金supported by the National Key R&DProject of China(2022YFC2702200 and 2021YFA1102900)the National Natural Science Foundation of China(32488101,32330030,82301921,32270909,82201881,92168205,31871448,31820103009,82022027,and 32300684)+9 种基金supported by the key project of the Science and Technology of Shanghai Municipality(19JC1415300 and 21JC1405500)the Natural Science Foundation of Shanghai(21ZR1450700)the ChinaPostdoctoral Science Foundation(2023M732660)the PostdoctoralFellowship Program of CPSF(GZB20230523)the Shanghai PilotProgram for Basic Research,the Shanghai Post-doctoral ExcellenceProgram(2022521,2022551,and 2023616)the China postdoctoral science foundation(2023M732660)the Postdoctoral Fellowship Program of CPSF(GZB20230523)the Fundamental Research Funds for the Central Universities(22120240435)the ShenzhenMedical Research Fund(B2402013)Peak Disciplines(TypeIV)of Institutions of Higher Learning in Shanghai.
文摘Assisted reproductive technology(ART)is associated with increased implantation failure and subsequent metabolic abnormalities in offspring,but the underlying mechanisms remain largely elusive.Here,we reveal that persistent Wnt signaling during the peri-implantation stage may be a key obstacle to the implantation of in vitro fertilization(IVF)embryos in a mouse model.Wnt activation affects the deposition of H3K27ac and H3K27me3 on pluripotency genes and bivalent genes,respectively,leading to the abnormal naïve-primed transition and suppressing expression of Otx2 in the epiblast.Furthermore,treatment with the Wnt inhibitor IWP2 promotes the redistribution of histone modifications and gene expression of epiblast.Importantly,Wnt inhibiting significantly improves implantation and intrauterine development of IVF embryos and subsequently ameliorates offspring metabolic abnormalities.Moreover,Wnt inhibiting markedly improves human peri-implantation embryo development and facilitates the transition from a naïve pluripotency state.Our study reveals a novel mechanism underlying the prevention of IVF embryo implantation failure and metabolic disorders in offspring.
