Mammalian embryogenesis begins with a totipotent zygote.Blastocyst-like structures can be captured by aggregated cells with extended pluripotent properties in a three-dimensional(3D)culture system.However,the efficien...Mammalian embryogenesis begins with a totipotent zygote.Blastocyst-like structures can be captured by aggregated cells with extended pluripotent properties in a three-dimensional(3D)culture system.However,the efficiency of generating blastoids is low,and it remains unclear whether other reported totipotent-like stem cells retain a similar capacity.In this study,we demonstrated that spliceosomal repression-induced totipotent blastomere-like cells(TBLCs)form blastocyst-like structures within around 80%of all microwells.In addition,we generated blastoids initiating from a single TBLC.TBLC-blastoids express specific markers of constituent cell lineages of a blastocyst and resemble blastocyst in cell-lineage allocation.Moreover,singlecell RNA sequencing revealed that TBLC-blastoids share a similar transcriptional profile to natural embryos,albeit composed of fewer primitive endoderm-like cells.Furthermore,TBLC-blastoids can develop beyond the implantation stage in vitro and induce decidualization in vivo.In summary,our findings provided an alternative cell type to efficiently generate blastoids for the study of early mouse embryogenesis.展开更多
Human pluripotent stem cells provide an inexhaustible model to study human embryogenesis in vitro.Recent studies have provided diverse models to generate human blastoids by self-organization of different pluripotent s...Human pluripotent stem cells provide an inexhaustible model to study human embryogenesis in vitro.Recent studies have provided diverse models to generate human blastoids by self-organization of different pluripotent stem cells or somatic reprogramming intermediates.However,whether blastoids can be generated from other cell types or whether they can recapitulate postimplantation development in vitro is unknown.Here,we develop a strategy to generate human blastoids from heterogeneous intermediates with epiblast,trophectoderm,and primitive endoderm signatures of the primed-to-naïve conversion process,which resemble natural blastocysts in morphological architecture,composition of cell lineages,transcriptome,and lineage differentiation potential.In addition,these blastoids reflect many features of human peri-implantation and pregastrulation development when further cultured in an in vitro 3D culture system.In summary,our study provides an alternative strategy to generate human blastoids and offers insights into human early embryogenesis by modeling peri-and postimplantation development in vitro.展开更多
Successful embryo implantation requires highly coordinated maternal-embryo interactions.Implantation failure is a major factor contributing to infertility.However,the mechanism underlying implantation failure remains ...Successful embryo implantation requires highly coordinated maternal-embryo interactions.Implantation failure is a major factor contributing to infertility.However,the mechanism underlying implantation failure remains unclear.An improved understanding of the early implantation process not only improves the success rate of assisted reproductive treatments but also helps in studying the pathophysiology of reproductive disorders.Owing to ethical concerns,in vivo studies of human embryo implantation are not feasible.However,the results obtained from animal models cannot be directly applied to humans.Over the years,in vitro implantation models have been developed to investigate implantation mechanisms.In this review,we discuss the use of different models for generating embryo-like surrogates to study early embryo development and implantation in vitro,with a specific focus on stem cell-derived blastocyst-like embryo surrogates.There is no definitive evidence that the recently established embryo-like models re-capitulate all developmental events of human embryos during the peri-implantation stage.Regardless,stem cell-derived embryo surrogates are the most valuable tools for studying the mechanisms of early cell lineage differentiation and developmental failures during implantation.展开更多
Self-organized blastoids from extended pluripotent stem(EPs)cells possess enormous potential for investigating postimplantation embryo development and related diseases.However,the limited ability of postimplantation d...Self-organized blastoids from extended pluripotent stem(EPs)cells possess enormous potential for investigating postimplantation embryo development and related diseases.However,the limited ability of postimplantation development of Eps-blastoids hinders its further application.In this study,single-cell transcriptomic analysis indicated that the“trophectoderm(TE)-like structure”of EPSblastoids was primarily composed of primitive endoderm(PrE)-related cells instead of TE-related cells.We further identified PrE-like cells in EPS cell culture that contribute to the blastoid formation with TE-like structure.Inhibition of PrE cell differentiation by inhibiting MEK signaling or knockout of Gata6 in EPS cells markedly suppressed EPS-blastoid formation.Furthermore,we demonstrated that blastocyst-like structures reconstituted by combining the EPs-derived bilineage embryo-like structure(BLEs)with either tetraploid embryos or tetraploid TE cells could implant normally and develop into live fetuses.In summary,our study reveals that TE improvement is critical for constructing a functional embryo using stem cells in vitro.展开更多
Stem cell-based embryo models present new opportunities to study early embryonic development.In a recent study,Kagawa et al.identified an approach to create human pluripotent stem cell-based blastoids that resemble th...Stem cell-based embryo models present new opportunities to study early embryonic development.In a recent study,Kagawa et al.identified an approach to create human pluripotent stem cell-based blastoids that resemble the human blastocysts.These blastoids efficiently generated analogs of the EPI,TE,PrE lineages with transcriptomes highly similar to those found in vivo.Furthermore,the formation of these lineages followed the same sequence and pace of blas-tocyst development,and was also dependent on the same pathways required for lineage specification.Finally,the blastoids were capable of attaching to stimulated endometrial cells to mimic the process of implantation.While more comprehensive analysis is needed to confirm its validity and usefulness,this new blastoid system presents the latest development in the attempt to model early human embryogenesis in vitro.展开更多
基金supported by the National Natural Science Foundation of China(32070800)。
文摘Mammalian embryogenesis begins with a totipotent zygote.Blastocyst-like structures can be captured by aggregated cells with extended pluripotent properties in a three-dimensional(3D)culture system.However,the efficiency of generating blastoids is low,and it remains unclear whether other reported totipotent-like stem cells retain a similar capacity.In this study,we demonstrated that spliceosomal repression-induced totipotent blastomere-like cells(TBLCs)form blastocyst-like structures within around 80%of all microwells.In addition,we generated blastoids initiating from a single TBLC.TBLC-blastoids express specific markers of constituent cell lineages of a blastocyst and resemble blastocyst in cell-lineage allocation.Moreover,singlecell RNA sequencing revealed that TBLC-blastoids share a similar transcriptional profile to natural embryos,albeit composed of fewer primitive endoderm-like cells.Furthermore,TBLC-blastoids can develop beyond the implantation stage in vitro and induce decidualization in vivo.In summary,our findings provided an alternative cell type to efficiently generate blastoids for the study of early mouse embryogenesis.
基金the Ministry of Science and Technology of China(Nos.2021YFA1102000,2021YFC2700300,2019YFA0110000,and 2018YFA0108900)the National Natural Science Foundation of China(NSFC)(Nos.31721003,32022024,32270850,32100633,31871486,32070652,and 81630035)the Science and Technology Commission of Shanghai Municipality(Nos.19JC1415300 and 21JC1405500).
文摘Human pluripotent stem cells provide an inexhaustible model to study human embryogenesis in vitro.Recent studies have provided diverse models to generate human blastoids by self-organization of different pluripotent stem cells or somatic reprogramming intermediates.However,whether blastoids can be generated from other cell types or whether they can recapitulate postimplantation development in vitro is unknown.Here,we develop a strategy to generate human blastoids from heterogeneous intermediates with epiblast,trophectoderm,and primitive endoderm signatures of the primed-to-naïve conversion process,which resemble natural blastocysts in morphological architecture,composition of cell lineages,transcriptome,and lineage differentiation potential.In addition,these blastoids reflect many features of human peri-implantation and pregastrulation development when further cultured in an in vitro 3D culture system.In summary,our study provides an alternative strategy to generate human blastoids and offers insights into human early embryogenesis by modeling peri-and postimplantation development in vitro.
基金supported in part by a General Research Fund(grant number:17111414)Research Grants Council of Hong Kong+3 种基金Health and Medical Research Fund(grant numbers:HMRF 04151546)Food and Health Bureau,Government of the Hong Kong Special Administrative RegionShenzhen Science and Technology Program(KQTD20190929172749226)The University of Hong Kong-Shenzhen Hospital Fund for Shenzhen Key Medical Discipline(SZXK2020089)
文摘Successful embryo implantation requires highly coordinated maternal-embryo interactions.Implantation failure is a major factor contributing to infertility.However,the mechanism underlying implantation failure remains unclear.An improved understanding of the early implantation process not only improves the success rate of assisted reproductive treatments but also helps in studying the pathophysiology of reproductive disorders.Owing to ethical concerns,in vivo studies of human embryo implantation are not feasible.However,the results obtained from animal models cannot be directly applied to humans.Over the years,in vitro implantation models have been developed to investigate implantation mechanisms.In this review,we discuss the use of different models for generating embryo-like surrogates to study early embryo development and implantation in vitro,with a specific focus on stem cell-derived blastocyst-like embryo surrogates.There is no definitive evidence that the recently established embryo-like models re-capitulate all developmental events of human embryos during the peri-implantation stage.Regardless,stem cell-derived embryo surrogates are the most valuable tools for studying the mechanisms of early cell lineage differentiation and developmental failures during implantation.
基金supported by the National Key R&D Program of China(Nos.2020YFA0112500 and 2021YFA1102900)the National Natural Science Foundation of China(Nos.31721003,81630035,82022027,31871448,32000418 and 31820103009)+2 种基金supported by the key project of the Science and Technology of Shanghai Municipality(Nos.19JC1415300 and 21JC1405500)the Shanghai municipal medical and health discipline construction projects(No.2017ZZ02015)the China Postdoctoral Science Foundation 2021M692437 and the Fundamental Research Funds for the Central Universities.
文摘Self-organized blastoids from extended pluripotent stem(EPs)cells possess enormous potential for investigating postimplantation embryo development and related diseases.However,the limited ability of postimplantation development of Eps-blastoids hinders its further application.In this study,single-cell transcriptomic analysis indicated that the“trophectoderm(TE)-like structure”of EPSblastoids was primarily composed of primitive endoderm(PrE)-related cells instead of TE-related cells.We further identified PrE-like cells in EPS cell culture that contribute to the blastoid formation with TE-like structure.Inhibition of PrE cell differentiation by inhibiting MEK signaling or knockout of Gata6 in EPS cells markedly suppressed EPS-blastoid formation.Furthermore,we demonstrated that blastocyst-like structures reconstituted by combining the EPs-derived bilineage embryo-like structure(BLEs)with either tetraploid embryos or tetraploid TE cells could implant normally and develop into live fetuses.In summary,our study reveals that TE improvement is critical for constructing a functional embryo using stem cells in vitro.
基金This work is supported by the Intramural Research Program of the NIH,National Institute of Environmental Health Sciences[Z01ES102745 to G.H.,in part].
文摘Stem cell-based embryo models present new opportunities to study early embryonic development.In a recent study,Kagawa et al.identified an approach to create human pluripotent stem cell-based blastoids that resemble the human blastocysts.These blastoids efficiently generated analogs of the EPI,TE,PrE lineages with transcriptomes highly similar to those found in vivo.Furthermore,the formation of these lineages followed the same sequence and pace of blas-tocyst development,and was also dependent on the same pathways required for lineage specification.Finally,the blastoids were capable of attaching to stimulated endometrial cells to mimic the process of implantation.While more comprehensive analysis is needed to confirm its validity and usefulness,this new blastoid system presents the latest development in the attempt to model early human embryogenesis in vitro.
