The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,...The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,we integrated single-cell transcriptomic analyses of human mesoderm cells from embryonic stem cells and embryos,enabling us to identify and define the molecular features of human hematopoietic mesoderm(HM)cells biased towards hematopoietic lineages.We discovered that BMP4 plays an essential role in HM specification and can serve as a marker for HM cells.Mechanistically,BMP4 acts as a downstream target of HDAC1,which modulates the expression of BMP4 by deacetylating its enhancer.Inhibition of HDAC significantly enhances HM specification and promotes subsequent hematopoietic cell differentiation.In conclusion,our study identifies human HM cells and describes new mechanisms for human hematopoietic development.展开更多
Located near the oropharynx, the tonsils are the primary mucosal immune organ. Tonsil tissue is a promising alternative source for the high-yield isolation of adult stem cells, and recent studies have reported the ide...Located near the oropharynx, the tonsils are the primary mucosal immune organ. Tonsil tissue is a promising alternative source for the high-yield isolation of adult stem cells, and recent studies have reported the identification and isolation of tonsil-derived stem cells (T-SCs) from waste surgical tissue following tonsillectomies in relatively young donors (i.e., under 10 years old). As such, TSCs offer several advantages, including superior proliferation and a shorter doubling time compared to bone marrow-derived mesenchymal stem cells (MSCs). T-SCs also exhibit multi-lineage differentiation, including mesodermal, endodermal (e.g., hepatocytes and parathyroid-like cells), and even ectodermal cells (e.g., Schwann cells). To this end, numbers of researchers have evaluated the practical use of T-SCs as an alternative source of autologous or allogenic MSCs. In this review, we summarize the details of T-SC isolation and identification and provide an overview of their application in cell therapy and regenerative medicine.展开更多
Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endod...Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endoderm induction after the MBT. It remains unclear which maternal factors activate zygotic expression of nodal genes in the ventrotateral blastodermal margin of the zebrafish blastulas. In this study, we show that loss of maternal Eomesodermin a （Eomesa）, a T-box transcription factor, impairs zygotic expression of the nodal genes ndr1 and ndr2 as well as mesodermal and endodermal markers, indicating an involvement in mesendoderm induction. Maternal Eomesa is also required for timely zygotic expression of the transcription factor gene mxtx2, a regulator of nodal gene expression. Eomesa directly binds to the Eomes-binding sites in the promoter or enhancer of ndr1, ndr2, and rnxtx2 to activate their transcrip- tion. Furthermore, human and mouse Nodal genes are also regulated by Eomes. Transfection of zebrafish eomesa into murine embryonic stem cells promotes mesendodermal differentiation with constant higher levels of endogenous Nodal expression, suggesting a conserved function of Eomes. Taken together, our findings reveal a conserved rote of maternal T-box transcription factors in regulating nodal gene expression and mesendoderm induction in vertebrate embryos.展开更多
The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth ...The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth movement,and connect tooth roots with bone.Severe periodontitis,deep caries,and trauma cause irreversible damage to this tissue,eventually leading to tooth loss through the destruction of tooth retention.Many patients suffer from these diseases worldwide,and its prevalence increases with age.To address this issue,regenerative medicine for damaged PDL tissue as well as the surrounding tissues has been extensively investigated regarding the potential and effectiveness of stem cells,scaffolds,and cytokines as well as their combined applications.In particular,PDL stem cells(PDLSCs)have been well studied.In this review,I discuss comprehensive studies on PDLSCs performed in vivo and contemporary reports focusing on the acquisition of large numbers of PDLSCs for therapeutic applications because of the very small number of PDLSCs available in vivo.展开更多
RUNXI is absolutely required for definitive hematopoiesis, but the function of RUNXlb/c, two isoforms of human RUNX1, is unclear. We established inducible RUNXlb/c-overexpressing human embryonic stem cell （hESC） lin...RUNXI is absolutely required for definitive hematopoiesis, but the function of RUNXlb/c, two isoforms of human RUNX1, is unclear. We established inducible RUNXlb/c-overexpressing human embryonic stem cell （hESC） lines, in which RUNXlb/c overexpression prevented the emergence of CD34＋ cells from early stage, thereby drastically reducing the production of hematopoi- etic stem/prognnitor cells. Simultaneously, the expression of hematopoiesis-related factors was downregulated. However, such blockage effect disappeared from day 6 in hESC/AGM-S3 ceU co-cultures, proving that the blockage occurred before the generation of hemogenic endothelial cells. This blockage was partially rescued by RepSox, an inhibitor of the transforming growth factor （TGF）-β signaling pathway, indicating a close relationship between RUNX1b/c and TGF-β pathway. Our results suggest a unique inhibitory function of RUNX1b/c in the development of early hematopoiesis and may aid further understanding of its biological function in normal and diseased models.展开更多
The transforming growth factor-β(TGF-β)family controls embryogenesis,stem cell differentiation,and tissue homeostasis.However,how post-translation modifications contribute to fine-tuning of TGF-βfamily signaling re...The transforming growth factor-β(TGF-β)family controls embryogenesis,stem cell differentiation,and tissue homeostasis.However,how post-translation modifications contribute to fine-tuning of TGF-βfamily signaling responses is not well understood.Inhibitory(I)-Smads can antagonize TGF-β/Smad signaling by recruiting Smurf E3 ubiquitin ligases to target the active TGF-βreceptor for proteasomal degradation.A proteomic interaction screen identified Vpr binding protein(VprBP)as novel binding partner of Smad7.Mis-expression studies revealed that VprBP negatively controls Smad2 phosphorylation,Smad2–Smad4 interaction,as well as TGF-βtarget gene expression.VprBP was found to promote Smad7–Smurf1–TβRI complex formation and induce proteasomal degradation of TGF-βtype I receptor(TβRI).Moreover,VprBP appears to stabilize Smurf1 by suppressing Smurf1 poly-ubiquitination.In multiple adult and mouse embryonic stem cells,depletion of VprBP promotes TGF-βor Activin-induced responses.In the mouse embryo VprBP expression negatively correlates with mesoderm marker expression,and VprBP attenuated mesoderm induction during zebrafish embryogenesis.Our findings thereby uncover a novel regulatory mechanism by which Smurf1 controls the TGF-βand Activin cascade and identify VprBP as a critical determinant of embryonic mesoderm induction.展开更多
Ca2＋ signals participate in various cellular processes with spatial and temporal dynamics, among which, inositol 1,4,5-trisphosphate receptors （IP3Rs）-mediated Ca2＋ signals are essential for early development. How...Ca2＋ signals participate in various cellular processes with spatial and temporal dynamics, among which, inositol 1,4,5-trisphosphate receptors （IP3Rs）-mediated Ca2＋ signals are essential for early development. However, the underlying mechanisms of IP3R- regulated cell fate decision remain largely unknown. Here we report that IP3Rs are required for the hematopoietic and cardiac fate divergence of mouse embryonic stem cells （mESCs）. Deletion of IP3Rs （IP3R-tKO） reduced FIkl＋/PDGFRα- hematopoietic mesoderm, c-Kit＋/CD41＋ hematopoietic progenitor ceil population, and the colony-forming unit activity, but increased cardiac progenitor markers as well as cardiomyocytes. Concomitantly, the expression of a key regulator of hematopoiesis, Ely2, was reduced in IP3R-tKO cells, which could be rescued by the activation of Ca2＋ signals and calcineurin or overexpression of constitutively active form of NFATc3. Furthermore, IP3R-tKO impaired specific targeting of Ely2 by NFATc3 via its evolutionarily conserved cis-element in differentiating ESCs. Importantly, the activation of Ca2＋-calcineurin-NFAT pathway reversed the phenotype of IP3R-tKO cells. These findings reveal an unrecognized governing role of IP3Rs in hematopoietic and cardiac fate commitment via IP3Rs-Ca2＋-calcineurin-NFATc3- Etv2 pathway.展开更多
基金supported by the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-073,2021-I2M-1-040,2022-I2M-JB-015)the National Key Research and Development Program of China(2021YFA1100703,2021YFA1103000)+2 种基金Haihe Laboratory of Cell Ecosystem Innovation Fund(22HHXBSS00031)the National Natural Science Foundation of China(82125003,32271161,82200141)Tianjin Municipal Science and Technology Commission Grant(20JCYBJC00240,22ZXSYSY00010,22JCQNJC01270)。
文摘The embryonic mesoderm comprises heterogeneous cell subpopulations with distinct lineage biases.It is unclear whether a bias for the human hematopoietic lineage emerges at this early developmental stage.In this study,we integrated single-cell transcriptomic analyses of human mesoderm cells from embryonic stem cells and embryos,enabling us to identify and define the molecular features of human hematopoietic mesoderm(HM)cells biased towards hematopoietic lineages.We discovered that BMP4 plays an essential role in HM specification and can serve as a marker for HM cells.Mechanistically,BMP4 acts as a downstream target of HDAC1,which modulates the expression of BMP4 by deacetylating its enhancer.Inhibition of HDAC significantly enhances HM specification and promotes subsequent hematopoietic cell differentiation.In conclusion,our study identifies human HM cells and describes new mechanisms for human hematopoietic development.
基金Supported by the Korea Health Technology RD Project through the Korea Health Industry Development Institutethe Ministry of Health and Welfare,No.HI16C-2207+1 种基金the Basic Science Research Program through the NRF,No.NRF-2018R1D1A1A09083264Ewha Womans University,No.RP-grant2017
文摘Located near the oropharynx, the tonsils are the primary mucosal immune organ. Tonsil tissue is a promising alternative source for the high-yield isolation of adult stem cells, and recent studies have reported the identification and isolation of tonsil-derived stem cells (T-SCs) from waste surgical tissue following tonsillectomies in relatively young donors (i.e., under 10 years old). As such, TSCs offer several advantages, including superior proliferation and a shorter doubling time compared to bone marrow-derived mesenchymal stem cells (MSCs). T-SCs also exhibit multi-lineage differentiation, including mesodermal, endodermal (e.g., hepatocytes and parathyroid-like cells), and even ectodermal cells (e.g., Schwann cells). To this end, numbers of researchers have evaluated the practical use of T-SCs as an alternative source of autologous or allogenic MSCs. In this review, we summarize the details of T-SC isolation and identification and provide an overview of their application in cell therapy and regenerative medicine.
基金Acknowledgements We thank Drs Alex Schier and Susan Mango （Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA） for discussion and suggestions, Dr David Kimelman （Department of Biochemistry, University of Washington, Seattle, WA, USA） for myc-eomesa construct, and members of the Meng lab for discussion and technical assistance. This work was financially supported by grants from the Major Science Research Programs of China （2011CB943800） and the National Natural Science Foundation of China （31221064）.
文摘Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endoderm induction after the MBT. It remains unclear which maternal factors activate zygotic expression of nodal genes in the ventrotateral blastodermal margin of the zebrafish blastulas. In this study, we show that loss of maternal Eomesodermin a （Eomesa）, a T-box transcription factor, impairs zygotic expression of the nodal genes ndr1 and ndr2 as well as mesodermal and endodermal markers, indicating an involvement in mesendoderm induction. Maternal Eomesa is also required for timely zygotic expression of the transcription factor gene mxtx2, a regulator of nodal gene expression. Eomesa directly binds to the Eomes-binding sites in the promoter or enhancer of ndr1, ndr2, and rnxtx2 to activate their transcrip- tion. Furthermore, human and mouse Nodal genes are also regulated by Eomes. Transfection of zebrafish eomesa into murine embryonic stem cells promotes mesendodermal differentiation with constant higher levels of endogenous Nodal expression, suggesting a conserved function of Eomes. Taken together, our findings reveal a conserved rote of maternal T-box transcription factors in regulating nodal gene expression and mesendoderm induction in vertebrate embryos.
基金Supported by Japan Society for the Promotion of Science,No.JP17H01598.
文摘The periodontal ligament(PDL)is an essential fibrous tissue for tooth retention in the alveolar bone socket.PDL tissue further functions to cushion occlusal force,maintain alveolar bone height,allow orthodontic tooth movement,and connect tooth roots with bone.Severe periodontitis,deep caries,and trauma cause irreversible damage to this tissue,eventually leading to tooth loss through the destruction of tooth retention.Many patients suffer from these diseases worldwide,and its prevalence increases with age.To address this issue,regenerative medicine for damaged PDL tissue as well as the surrounding tissues has been extensively investigated regarding the potential and effectiveness of stem cells,scaffolds,and cytokines as well as their combined applications.In particular,PDL stem cells(PDLSCs)have been well studied.In this review,I discuss comprehensive studies on PDLSCs performed in vivo and contemporary reports focusing on the acquisition of large numbers of PDLSCs for therapeutic applications because of the very small number of PDLSCs available in vivo.
基金This work was supported by the National Program on Key Basic Research Project of China （973 Program 2015CB964902）, the National Natural Science Foundation of China （NSFC H81170466 and H81370597）, and the CAMS Initiatives for Innovative Medicine （2016-12M-1-018） awarded to F.M.
文摘RUNXI is absolutely required for definitive hematopoiesis, but the function of RUNXlb/c, two isoforms of human RUNX1, is unclear. We established inducible RUNXlb/c-overexpressing human embryonic stem cell （hESC） lines, in which RUNXlb/c overexpression prevented the emergence of CD34＋ cells from early stage, thereby drastically reducing the production of hematopoi- etic stem/prognnitor cells. Simultaneously, the expression of hematopoiesis-related factors was downregulated. However, such blockage effect disappeared from day 6 in hESC/AGM-S3 ceU co-cultures, proving that the blockage occurred before the generation of hemogenic endothelial cells. This blockage was partially rescued by RepSox, an inhibitor of the transforming growth factor （TGF）-β signaling pathway, indicating a close relationship between RUNX1b/c and TGF-β pathway. Our results suggest a unique inhibitory function of RUNX1b/c in the development of early hematopoiesis and may aid further understanding of its biological function in normal and diseased models.
基金This research was supported by Cancer Genomics Centre Netherlands and a grant from the National Natural Science Foundation of China(31471315).
文摘The transforming growth factor-β(TGF-β)family controls embryogenesis,stem cell differentiation,and tissue homeostasis.However,how post-translation modifications contribute to fine-tuning of TGF-βfamily signaling responses is not well understood.Inhibitory(I)-Smads can antagonize TGF-β/Smad signaling by recruiting Smurf E3 ubiquitin ligases to target the active TGF-βreceptor for proteasomal degradation.A proteomic interaction screen identified Vpr binding protein(VprBP)as novel binding partner of Smad7.Mis-expression studies revealed that VprBP negatively controls Smad2 phosphorylation,Smad2–Smad4 interaction,as well as TGF-βtarget gene expression.VprBP was found to promote Smad7–Smurf1–TβRI complex formation and induce proteasomal degradation of TGF-βtype I receptor(TβRI).Moreover,VprBP appears to stabilize Smurf1 by suppressing Smurf1 poly-ubiquitination.In multiple adult and mouse embryonic stem cells,depletion of VprBP promotes TGF-βor Activin-induced responses.In the mouse embryo VprBP expression negatively correlates with mesoderm marker expression,and VprBP attenuated mesoderm induction during zebrafish embryogenesis.Our findings thereby uncover a novel regulatory mechanism by which Smurf1 controls the TGF-βand Activin cascade and identify VprBP as a critical determinant of embryonic mesoderm induction.
基金This study was supported by grants from the National Natural Science Foundation of China （31030050, 81520108004, and 81470422 to H.-T.Y.）, the Strategic Priority Research Program of Chinese Academy of Sciences （XDA01020204 to H.-T.Y.）, the National Basic Research Program of China （2014CB965100 to H.-T.Y.）, the National Science and Technology Major Project （2012ZX09501001 to H.-T.Y.）, and the Shenzhen Science, Technology and Innovation Committee OCYI 20160428154108239 to K.O.）.
文摘Ca2＋ signals participate in various cellular processes with spatial and temporal dynamics, among which, inositol 1,4,5-trisphosphate receptors （IP3Rs）-mediated Ca2＋ signals are essential for early development. However, the underlying mechanisms of IP3R- regulated cell fate decision remain largely unknown. Here we report that IP3Rs are required for the hematopoietic and cardiac fate divergence of mouse embryonic stem cells （mESCs）. Deletion of IP3Rs （IP3R-tKO） reduced FIkl＋/PDGFRα- hematopoietic mesoderm, c-Kit＋/CD41＋ hematopoietic progenitor ceil population, and the colony-forming unit activity, but increased cardiac progenitor markers as well as cardiomyocytes. Concomitantly, the expression of a key regulator of hematopoiesis, Ely2, was reduced in IP3R-tKO cells, which could be rescued by the activation of Ca2＋ signals and calcineurin or overexpression of constitutively active form of NFATc3. Furthermore, IP3R-tKO impaired specific targeting of Ely2 by NFATc3 via its evolutionarily conserved cis-element in differentiating ESCs. Importantly, the activation of Ca2＋-calcineurin-NFAT pathway reversed the phenotype of IP3R-tKO cells. These findings reveal an unrecognized governing role of IP3Rs in hematopoietic and cardiac fate commitment via IP3Rs-Ca2＋-calcineurin-NFATc3- Etv2 pathway.
