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Mechanisms of Development Apr 2017Adhesion differences are the main driver of cell sorting and related processes such as boundary formation or tissue positioning. In the early amphibian embryo, graded... (Review)
Review
Adhesion differences are the main driver of cell sorting and related processes such as boundary formation or tissue positioning. In the early amphibian embryo, graded variations in cadherin density and localized expression of adhesion-modulating factors are associated with regional differences in adhesive properties including overall adhesion strength. The role of these differences in embryonic boundary formation has not been studied extensively, but available evidence suggests that adhesion strength differentials are not essential. On the other hand, the inside-out positioning of the germ layers is correlated with adhesion strength, although the biological significance of this effect is unclear. By contrast, the positioning of dorsal mesoderm tissues along the anterior-posterior body axis is essential for axis elongation, but the underlying sorting mechanism is not correlated with adhesion strength, and may rely on specific cell adhesion. Formation of the ectoderm-mesoderm boundary is the best understood sorting related process in the frog embryo. It relies on contact-induced cell repulsion at the tissue interface, driven by Eph-ephrin signaling and paraxial protocadherin-dependent self/non-self recognition.
Topics: Animals; Cadherins; Cell Adhesion; Cell Communication; Cell Movement; Ectoderm; Embryo, Nonmammalian; Endoderm; Ephrins; Gene Expression Regulation, Developmental; Mesoderm; Receptors, Eph Family; Signal Transduction; Xenopus Proteins; Xenopus laevis
PubMed: 27697520
DOI: 10.1016/j.mod.2016.09.003 -
Circulation Research Feb 2023Studies in animal models tracing organogenesis of the mesoderm-derived heart have emphasized the importance of signals coming from adjacent endodermal tissues in... (Review)
Review
Studies in animal models tracing organogenesis of the mesoderm-derived heart have emphasized the importance of signals coming from adjacent endodermal tissues in coordinating proper cardiac morphogenesis. Although in vitro models such as cardiac organoids have shown great potential to recapitulate the physiology of the human heart, they are unable to capture the complex crosstalk that takes place between the co-developing heart and endodermal organs, partly due to their distinct germ layer origins. In an effort to address this long-sought challenge, recent reports of multilineage organoids comprising both cardiac and endodermal derivatives have energized the efforts to understand how inter-organ, cross-lineage communications influence their respective morphogenesis. These co-differentiation systems have produced intriguing findings of shared signaling requirements for inducing cardiac specification together with primitive foregut, pulmonary, or intestinal lineages. Overall, these multilineage cardiac organoids offer an unprecedented window into human development that can reveal how the endoderm and heart cooperate to direct morphogenesis, patterning, and maturation. Further, through spatiotemporal reorganization, the co-emerged multilineage cells self-assemble into distinct compartments as seen in the cardiac-foregut, cardiac-intestine, and cardiopulmonary organoids and undergo cell migration and tissue reorganization to establish tissue boundaries. Looking into the future, these cardiac incorporated, multilineage organoids will inspire future strategies for improved cell sourcing for regenerative interventions and provide more effective models for disease investigation and drug testing. In this review, we will introduce the developmental context of coordinated heart and endoderm morphogenesis, discuss strategies for in vitro co-induction of cardiac and endodermal derivatives, and finally comment on the challenges and exciting new research directions enabled by this breakthrough.
Topics: Animals; Humans; Endoderm; Cell Differentiation; Organoids; Intestines; Morphogenesis
PubMed: 36795851
DOI: 10.1161/CIRCRESAHA.122.321769 -
Journal of Molecular Medicine (Berlin,... Apr 2021Organoids derived from human pluripotent stem cells (hPSCs) have emerged as important models for investigating human-specific aspects of development and disease. Here we... (Review)
Review
Organoids derived from human pluripotent stem cells (hPSCs) have emerged as important models for investigating human-specific aspects of development and disease. Here we discuss hPSC-derived organoids through the lens of development-highlighting how stages of human development align with the development of hPSC-derived organoids in the tissue culture dish. Using hPSC-derived lung and intestinal organoids as examples, we discuss the value and application of such systems for understanding human biology, as well as strategies for enhancing organoid complexity and maturity.
Topics: Cell Differentiation; Cell Lineage; Forecasting; Germ Layers; Humans; Induced Pluripotent Stem Cells; Intestines; Lung; Organ Specificity; Organoids
PubMed: 32857169
DOI: 10.1007/s00109-020-01969-w -
Cytometry. Part a : the Journal of the... Aug 2022Mouse embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs) are both pluripotent stem cells from early embryos. Another type of pluripotent stem cells, which are...
Mouse embryonic stem cells (ESCs) and epiblast stem cells (EpiSCs) are both pluripotent stem cells from early embryos. Another type of pluripotent stem cells, which are similar with EpiSCs and derive from pre-implantation embryos in feeder-free and chemically defined medium containing Activin A and basic fibroblast growth factors (bFGF), is termed as AFSCs. The pluripotency and self-renewal maintenance of ESCs rely on Leukemia inhibitory factor (LIF)/STAT/BMP4/SMAD signaling, while the pluripotency and self-renewal maintenance of EpiSCs and AFSCs rely on bFGF and Activin/Nodal signaling. However, the establishment efficiency of AFSCs lines is low. In this study, we stimulated early embryos by 2i/LIF (CHIR99021 + PD0325901 + LIF) and Activin A + bFGF respectively, to change the cell fate in inner cell mass (ICM). The "fate changed embryos" by 2i/LIF can efficiently produce AFSCs in feeder-free and chemically defined medium, but the efficiency of embryos treated with Activin A + bFGF were poor. The AFSCs from fate-changed embryos share similar molecular characteristics with conventional AFSCs and EpiSCs. Our results suggest that the advanced stimulation of 2i/LIF and the premature stimulation of Activin A + bFGF contribute to capturing the pluripotent stem cells in early embryos, and the FGF/MAPK signaling dominate early embryo development. Our study provides a new approach to capturing pluripotency from pre-implantation embryos.
Topics: Animals; Cell Differentiation; Embryonic Stem Cells; Germ Layers; Mice; Pluripotent Stem Cells; Signal Transduction
PubMed: 35332996
DOI: 10.1002/cyto.a.24551 -
The Keio Journal of Medicine Sep 2022Pluripotent stem cells (PSCs), which include embryonic stem cells and induced pluripotent stem cells, have the potential for unlimited self-renewal and proliferation and... (Review)
Review
Pluripotent stem cells (PSCs), which include embryonic stem cells and induced pluripotent stem cells, have the potential for unlimited self-renewal and proliferation and the ability to differentiate into all three embryonic germ layers. Human PSCs (hPSCs) are used in drug discovery screening, disease models, and regenerative medicine. These cells maintain a transcriptional regulatory network based on a set of unique transcription factors to maintain their stem cell properties. Downstream of such transcriptional regulatory networks, various stem cell-specific metabolic programs are used to produce energy and metabolites as necessary. hPSCs and differentiated cells utilize different metabolic programs for self-renewal ability and maintenance of quiescence. Understanding the different metabolic features of hPSCs and differentiated cells can contribute to the development of technologies that are useful for regenerative medicine, such as the purification of differentiated cells. This review describes the unique metabolic programs active in hPSCs and their differences from somatic cells, with a focus on cardiomyocytes.
Topics: Cell Differentiation; Germ Layers; Humans; Induced Pluripotent Stem Cells; Myocytes, Cardiac; Pluripotent Stem Cells; Transcription Factors
PubMed: 35082186
DOI: 10.2302/kjm.2021-0015-IR -
Current Opinion in Cell Biology Oct 2017It is during gastrulation that the primordial germ layers are specified, embryonic axes become morphologically manifest, and the embryonic body plan begins to take... (Review)
Review
It is during gastrulation that the primordial germ layers are specified, embryonic axes become morphologically manifest, and the embryonic body plan begins to take shape. As morphogenetic movements push and pull nascent tissues into position within the gastrula, new interactions are established between neighboring cells and tissues. These interactions represent an emergent property within gastrulating embryos, and serve to regulate and promote ensuing morphogenesis that establishes the next set of cell/tissue contacts, and so on. Several recent studies demonstrate the critical roles of such interactions during gastrulation, including those between germ layers, along embryonic axes, and at tissue boundaries. Emergent tissue interactions result from - and result in - morphogen signaling, cell contacts, and mechanical forces within the gastrula. Together, these comprise a dynamic and complex regulatory cascade that drives gastrulation morphogenesis.
Topics: Animals; Ectoderm; Embryo, Mammalian; Embryo, Nonmammalian; Gastrula; Gastrulation; Mesoderm; Morphogenesis; Signal Transduction
PubMed: 28586710
DOI: 10.1016/j.ceb.2017.04.006 -
BMC Molecular and Cell Biology May 2020Members of the T-box family of DNA-binding proteins play a prominent role in the differentiation of the three primary germ layers. VegT, Brachyury, and Eomesodermin...
BACKGROUND
Members of the T-box family of DNA-binding proteins play a prominent role in the differentiation of the three primary germ layers. VegT, Brachyury, and Eomesodermin function as transcriptional activators and, in addition to directly activating the transcription of endoderm- and mesoderm-specific genes, serve as regulators of growth factor signaling during induction of these germ layers. In contrast, the T-box gene, tbx2, is expressed in the embryonic ectoderm, where Tbx2 functions as a transcriptional repressor and inhibits mesendodermal differentiation by the TGFβ ligand Activin. Tbx2 misexpression also promotes dorsal ectodermal fate via inhibition of the BMP branch of the TGFβ signaling network.
RESULTS
Here, we report a physical association between Tbx2 and both Smad1 and Smad2, mediators of BMP and Activin/Nodal signaling, respectively. We perform structure/function analysis of Tbx2 to elucidate the roles of both Tbx2-Smad interaction and Tbx2 DNA-binding in germ layer suppression.
CONCLUSION
Our studies demonstrate that Tbx2 associates with intracellular mediators of the Activin/Nodal and BMP/GDF pathways. We identify a novel repressor domain within Tbx2, and have determined that Tbx2 DNA-binding activity is required for repression of TGFβ signaling. Finally, our data also point to overlapping yet distinct mechanisms for Tbx2-mediated repression of Activin/Nodal and BMP/GDF signaling.
Topics: Activins; Animals; Body Patterning; Bone Morphogenetic Proteins; Ectoderm; Gene Expression Regulation, Developmental; Germ Layers; Growth Differentiation Factors; Phosphorylation; Protein Domains; Signal Transduction; Smad1 Protein; Smad2 Protein; T-Box Domain Proteins; Transforming Growth Factor beta; Xenopus Proteins; Xenopus laevis
PubMed: 32466750
DOI: 10.1186/s12860-020-00282-1 -
The International Journal of... Oct 2015Gene expression is epigenetically regulated through DNA methylation and covalent chromatin modifications, such as acetylation, phosphorylation, ubiquitination,... (Review)
Review
Gene expression is epigenetically regulated through DNA methylation and covalent chromatin modifications, such as acetylation, phosphorylation, ubiquitination, sumoylation, and methylation of histones. Histone methylation state is dynamically regulated by different groups of histone methyltransferases and demethylases. The trimethylation of histone 3 (H3K4) at lysine 4 is usually associated with the activation of gene expression, whereas trimethylation of histone 3 at lysine 27 (H3K27) is associated with the repression of gene expression. The polycomb repressive complex contains the H3K27 methyltransferase Ezh2 and controls dimethylation and trimethylation of H3K27 (H3K27me2/3). The Jumonji domain containing-3 (Jmjd3, KDM6B) and ubiquitously transcribed X-chromosome tetratricopeptide repeat protein (UTX, KDM6A) have been identified as H3K27 demethylases that catalyze the demethylation of H3K27me2/3. The role and mechanisms of both JMJD3 and UTX have been extensively studied for their involvement in development, cell plasticity, immune system, neurodegenerative disease, and cancer. In this review, we will focus on recent progresses made on understanding JMJD3 in the regulation of gene expression in development and diseases. This article is part of a Directed Issue entitled: Epigenetics dynamics in development and disease.
Topics: Animals; Chromatin; Enhancer of Zeste Homolog 2 Protein; Epigenesis, Genetic; Gene Expression Regulation, Developmental; Germ Layers; Histone Demethylases; Histones; Humans; Immunity, Innate; Jumonji Domain-Containing Histone Demethylases; Lysine; Mice; Neoplasms; Neurodegenerative Diseases; Nuclear Proteins; Polycomb Repressive Complex 2
PubMed: 26193001
DOI: 10.1016/j.biocel.2015.07.006 -
Current Topics in Developmental Biology 2022Ectodermal organs originate from the outermost germ layer of the developing embryo and include the skin, hair, tooth, nails, and exocrine glands. These organs develop...
Ectodermal organs originate from the outermost germ layer of the developing embryo and include the skin, hair, tooth, nails, and exocrine glands. These organs develop through tightly regulated, sequential and reciprocal epithelial-mesenchymal crosstalk, and they eventually assume various morphologies and functions while retaining the ability to regenerate. As with many other tissues in the body, the development and morphogenesis of these organs are regulated by a set of common signaling pathways, such as Shh, Wnt, Bmp, Notch, Tgf-β, and Eda. However, subtle differences in the temporal activation, the multiple possible combinations of ligand-receptor activation, the various cofactors, as well as the underlying epigenetic modulation determine how each organ develops into its adult form. Although each organ has been studied separately in considerable detail, the mechanisms underlying the parallels and differences in signaling that regulate their development have rarely been investigated. First, we will use the tooth, the hair follicle, and the mammary gland as representative ectodermal organs to explore how the development of signaling centers and establishment of stem cell populations influence overall growth and morphogenesis. Then we will compare how some of the major signaling pathways (Shh, Wnt, Notch and Yap/Taz) differentially regulate developmental events. Finally, we will discuss how signaling regulates regenerative processes in all three.
Topics: Ectoderm; Hair Follicle; Morphogenesis; Signal Transduction; Transforming Growth Factor beta
PubMed: 35606061
DOI: 10.1016/bs.ctdb.2022.02.006 -
Lab on a Chip Nov 2021Human induced pluripotent stem cells (hiPSCs) can serve as an unlimited source to rebuild organotypic tissues . Successful engineering of functional cell types and...
Human induced pluripotent stem cells (hiPSCs) can serve as an unlimited source to rebuild organotypic tissues . Successful engineering of functional cell types and complex organ structures outside the human body requires knowledge of the chemical, temporal, and spatial microenvironment of their counterparts. Despite an increased understanding of mouse and human embryonic development, screening approaches are still required for the optimization of stem cell differentiation protocols to gain more functional mature cell types. The liver, lung, pancreas, and digestive tract originate from the endoderm germ layer. Optimization and specification of the earliest differentiation step, which is the definitive endoderm (DE), is of central importance for generating cell types of these organs because off-target cell types will propagate during month-long cultivation steps and reduce yields. Here, we developed a microfluidic large-scale integration (mLSI) chip platform for combined automated three-dimensional (3D) cell culturing and high-throughput imaging to investigate anterior/posterior patterns occurring during hiPSC differentiation into DE cells. Integration of 3D cell cultures with a diameter of 150 μm was achieved using a U-shaped pneumatic membrane valve, which was geometrically optimized and fluidically characterized. Upon parallelization of 32 fluidically individually addressable cell culture unit cells with a total of 128 3D cell cultures, complex and long-term DE differentiation protocols could be automated. Real-time bright-field imaging was used to analyze cell growth during DE differentiation, and immunofluorescence imaging on optically cleared 3D cell cultures was used to determine the DE differentiation yield. By systematically alternating transforming growth factor β (TGF-β) and WNT signaling agonist concentrations and temporal stimulation, we showed that even under similar DE differentiation yields, there were patterning differences in the 3D cell cultures, indicating possible differentiation differences between established DE protocols. The automated mLSI chip platform with the general analytical workflow for 3D stem cell cultures offers the optimization of generation of various cell types for cell replacement therapies.
Topics: Cell Culture Techniques; Cell Differentiation; Endoderm; Humans; Induced Pluripotent Stem Cells
PubMed: 34751293
DOI: 10.1039/d1lc00565k