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Seminars in Cell & Developmental Biology Aug 2012Recent advances in generating pancreatic cell types from human pluripotent stem cells has depended on our knowledge of the developmental processes that regulate pancreas... (Review)
Review
Recent advances in generating pancreatic cell types from human pluripotent stem cells has depended on our knowledge of the developmental processes that regulate pancreas development in vivo. The developmental events between gastrulation and formation of the embryonic pancreatic primordia are both rapid and dynamic and studies in frog, fish, chick, and mouse have identified the molecular basis of how the pancreas develops from multipotent endoderm progenitors. Here, we review the current status of our understanding of molecular mechanisms that control endoderm formation, endoderm patterning, and pancreas specification and highlight how these discoveries have allowed for the development of robust methods to generate pancreatic cells from human pluripotent stem cells.
Topics: Animals; Endoderm; Humans; Organogenesis; Pancreas; Pluripotent Stem Cells; Signal Transduction
PubMed: 22743233
DOI: 10.1016/j.semcdb.2012.06.009 -
Philosophical Transactions of the Royal... Dec 2022The blastocyst is a conserved stage and distinct milestone in the development of the mammalian embryo. Blastocyst stage embryos comprise three cell lineages which arise... (Review)
Review
The blastocyst is a conserved stage and distinct milestone in the development of the mammalian embryo. Blastocyst stage embryos comprise three cell lineages which arise through two sequential binary cell fate specification steps. In the first, extra-embryonic trophectoderm (TE) cells segregate from inner cell mass (ICM) cells. Subsequently, ICM cells acquire a pluripotent epiblast (Epi) or extra-embryonic primitive endoderm (PrE, also referred to as hypoblast) identity. In the mouse, nascent Epi and PrE cells emerge in a salt-and-pepper distribution in the early blastocyst and are subsequently sorted into adjacent tissue layers by the late blastocyst stage. Epi cells cluster at the interior of the ICM, while PrE cells are positioned on its surface interfacing the blastocyst cavity, where they display apicobasal polarity. As the embryo implants into the maternal uterus, cells at the periphery of the PrE epithelium, at the intersection with the TE, break away and migrate along the TE as they mature into parietal endoderm (ParE). PrE cells remaining in association with the Epi mature into visceral endoderm. In this review, we discuss our current understanding of the PrE from its specification to its maturation. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.
Topics: Animals; Blastocyst; Cell Differentiation; Cell Lineage; Endoderm; Female; Germ Layers; Mammals; Mice
PubMed: 36252215
DOI: 10.1098/rstb.2021.0252 -
Biomolecules Apr 2022The regulation of proteins through the addition and removal of -linked β--acetylglucosamine (-GlcNAc) plays a role in many signaling events, specifically in stem cell...
The regulation of proteins through the addition and removal of -linked β--acetylglucosamine (-GlcNAc) plays a role in many signaling events, specifically in stem cell pluripotency and the regulation of differentiation. However, these post-translational modifications have not been explored in extraembryonic endoderm (XEN) differentiation. Of the plethora of proteins regulated through -GlcNAc, we explored galectin-3 as a candidate protein known to have various intracellular and extracellular functions. Based on other studies, we predicted a reduction in global -GlcNAcylation levels and a distinct galectin expression profile in XEN cells relative to embryonic stem (ES) cells. By conducting dot blot analysis, XEN cells had decreased levels of global -GlcNAc than ES cells, which reflected a disbalance in the expression of genes encoding -GlcNAc cycle enzymes. Immunoassays (Western blot and ELISA) revealed that although XEN cells (low -GlcNAc) had lower concentrations of both intracellular and extracellular galectin-3 than ES cells (high -GlcNAc), the relative secretion of galectin-3 was significantly increased by XEN cells. Inducing ES cells toward XEN in the presence of an -GlcNAcase inhibitor was not sufficient to inhibit XEN differentiation. However, global -GlcNAcylation was found to decrease in differentiated cells and the extracellular localization of galectin-3 accompanies these changes. Inhibiting global -GlcNAcylation status does not, however, impact pluripotency and the ability of ES cells to differentiate to the XEN lineage.
Topics: Cell Differentiation; Embryonic Stem Cells; Endoderm; Galectin 3; Galectins
PubMed: 35625551
DOI: 10.3390/biom12050623 -
Developmental Biology Apr 2023Gastrulation is the first dynamic cell movement during embryogenesis. Endoderm and mesoderm cells are internalized into embryos during this process. Ascidian embryos...
Gastrulation is the first dynamic cell movement during embryogenesis. Endoderm and mesoderm cells are internalized into embryos during this process. Ascidian embryos provide a simple system for studying gastrulation in chordates. Gastrulation starts in spherical late 64-cell embryos with 10 endoderm blastomeres. The mechanisms of gastrulation in ascidians have been investigated, and a two-step model has been proposed. The first step involves apical constriction of endoderm cells, followed by apicobasal shortening in the second step. In this study, isolated ascidian endoderm progenitor cells displayed dynamic blebbing activity at the gastrula stage, although such a dynamic cell-shape change was not recognized in toto. Blebbing is often observed in migrating animal cells. In ascidians, endoderm cells displayed blebbing activity, while mesoderm and ectoderm cells did not. The timing of blebbing of isolated endoderm cells coincided with that of cell invagination. The constriction rate of apical surfaces correlated with the intensity of blebbing activity in each endoderm-lineage cell. Fibroblast growth factor (FGF) signaling was both necessary and sufficient for inducing blebbing activity, independent of cell fate specification. In contrast, the timing of initiation of blebbing and intensity of blebbing response to FGF signaling were controlled by intrinsic cellular factors. It is likely that the difference in intensity of blebbing activity between the anterior A-line and posterior B-line cells could account for the anteroposterior difference in the steepness of the archenteron wall. Inhibition of zygotic transcription, FGF signaling, and Rho kinase, all of which suppressed blebbing activity, resulted in incomplete apical constriction and failure of the eventual formation of cup-shaped gastrulae. Blebbing activity was involved in the progression and maintenance of apical constriction, but not in apicobasal shortening in whole embryos. Apical constriction is mediated by distinct blebbing-dependent and blebbing-independent mechanisms. Surface tension and consequent membrane contraction may not be the sole mechanical force for apical constriction and formation of cup-shaped gastrulae. The present study reveals the hidden cellular potential of endodermal cells during gastrulation and discusses the possible roles of blebbing in the invagination process.
Topics: Animals; Gastrulation; Urochordata; Endoderm; Blastomeres; Gastrula; Fibroblast Growth Factors
PubMed: 36702215
DOI: 10.1016/j.ydbio.2023.01.007 -
Frontiers in Endocrinology 2021The mechanisms underlying thyroid gland development have a central interest in biology and this review is aimed to provide an update on the recent advancements on the... (Review)
Review
The mechanisms underlying thyroid gland development have a central interest in biology and this review is aimed to provide an update on the recent advancements on the early steps of thyroid differentiation that were obtained in the zebrafish, because this teleost fish revealed to be a suitable organism to study the early developmental stages. Physiologically, the thyroid precursors fate is delineated by the appearance among the endoderm cells of the foregut of a restricted cell population expressing specific transcription factors, including , , and . The committed thyroid primordium first appears as a thickening of the pharyngeal floor of the anterior endoderm, that subsequently detaches from the floor and migrates to its final location where it gives rise to the thyroid hormone-producing follicles. At variance with mammalian models, thyroid precursor differentiation in zebrafish occurs early during the developmental process before the dislocation to the eutopic positioning of thyroid follicles. Several pathways have been implicated in these early events and nowadays there is evidence of a complex crosstalk between intrinsic (coming from the endoderm and thyroid precursors) and extrinsic factors (coming from surrounding tissues, as the cardiac mesoderm) whose organization in time and space is probably required for the proper thyroid development. In particular, Notch, Shh, Fgf, Bmp, and Wnt signaling seems to be required for the commitment of endodermal cells to a thyroid fate at specific developmental windows of zebrafish embryo. Here, we summarize the recent findings produced in the various zebrafish experimental models with the aim to define a comprehensive picture of such complicated puzzle.
Topics: Animals; Cell Differentiation; Embryo, Nonmammalian; Endoderm; Gene Expression Regulation, Developmental; Morphogenesis; Stem Cells; Thyroid Gland; Zebrafish; Zebrafish Proteins
PubMed: 34149617
DOI: 10.3389/fendo.2021.664557 -
The International Journal of... 2013Embryonic stem cells (ESCs) have the potential to be used as unlimited resources for tissue replacement therapy, thereby compensating for organ donor shortage. To reach... (Review)
Review
Embryonic stem cells (ESCs) have the potential to be used as unlimited resources for tissue replacement therapy, thereby compensating for organ donor shortage. To reach this goal, the molecular principles governing early differentiation events in the developing embryo need to be addressed, understood and properly implemented in vitro. Studies carried out in several vertebrate models have established that Nodal/Activin A, BMP, WNT and FGF signaling pathways regulate early embryo development and that these pathways are similarly used during germ layer formation by cultured ESCs. However, differences have also been identified in the way these pathways function or interact in mouse vs. human ESCs, making it sometimes difficult to extrapolate findings from one system to the other. In this review, we discuss and compare the role of the relevant signaling pathways and their crosstalk during undifferentiated growth and during the endoderm differentiation of mouse and human ESCs.
Topics: Activins; Animals; Bone Morphogenetic Proteins; Cell Differentiation; Embryonic Stem Cells; Endoderm; Fibroblast Growth Factors; Humans; Mice; Nodal Protein; Signal Transduction; Wnt Proteins
PubMed: 23585347
DOI: 10.1387/ijdb.120115ls -
Cell Proliferation May 2019To date, many efforts have been made to establish porcine embryonic stem (pES) cells without success. Extraembryonic endoderm (XEN) cells can self-renew and...
OBJECTIVES
To date, many efforts have been made to establish porcine embryonic stem (pES) cells without success. Extraembryonic endoderm (XEN) cells can self-renew and differentiate into the visceral endoderm and parietal endoderm. XEN cells are derived from the primitive endoderm of the inner cell mass of blastocysts and may be an intermediate state in cell reprogramming.
MATERIALS AND METHODS
Porcine XEN cells (pXENCs) were generated from porcine pluripotent stem cells (pPSCs) and were characterized by RNA sequencing and immunofluorescence analyses. The developmental potential of pXENCs was investigated in chimeric mouse embryos.
RESULTS
Porcine XEN cells derived from porcine pPSCs were successfully expanded in N2B27 medium supplemented with bFGF for least 30 passages. RNA sequencing and immunofluorescence analyses showed that pXENCs expressed the murine and canine XEN markers Gata6, Gata4, Sox17 and Pdgfra but not the pluripotent markers Oct4, Sox2 and TE marker Cdx2. Moreover, these cells contributed to the XEN when injected into four-cell stage mouse embryos. Supplementation with Chir99021 and SB431542 promoted the pluripotency of the pXENCs.
CONCLUSIONS
We successfully derived pXENCs and showed that supplementation with Chir99021 and SB431542 confer them with pluripotency. Our results provide a new resource for investigating the reprogramming mechanism of porcine-induced pluripotent stem cells.
Topics: Animals; Cell Culture Techniques; Cell Differentiation; Cell Line; Coculture Techniques; Dogs; Embryonic Stem Cells; Endoderm; Gene Expression; Mice; Pluripotent Stem Cells; Sequence Analysis, RNA; Signal Transduction; Swine; Transplantation Chimera
PubMed: 30896067
DOI: 10.1111/cpr.12591 -
Current Opinion in Genetics &... Dec 2023The primitive endoderm (PrE, also named hypoblast), a predominantly extraembryonic epithelium that arises from the inner cell mass (ICM) of the mammalian... (Review)
Review
The primitive endoderm (PrE, also named hypoblast), a predominantly extraembryonic epithelium that arises from the inner cell mass (ICM) of the mammalian pre-implantation blastocyst, plays a fundamental role in embryonic development, giving rise to the yolk sac, establishing the anterior-posterior axis and contributing to the gut. PrE is specified from the ICM at the same time as the epiblast (Epi) that will form the embryo proper. While in vitro cell lines resembling the pluripotent Epi have been derived from a variety of conditions, only one model system currently exists for the PrE, naïve extraembryonic endoderm (nEnd). As a result, considerably more is known about the gene regulatory networks and signalling requirements of pluripotent stem cells than nEnd. In this review, we describe the ontogeny and differentiation of the PrE or hypoblast in mouse and primate and then discuss in vitro cell culture models for different extraembryonic endodermal cell types.
Topics: Pregnancy; Female; Humans; Mice; Animals; Endoderm; Germ Layers; Cell Differentiation; Embryo, Mammalian; Blastocyst; Mammals
PubMed: 37783145
DOI: 10.1016/j.gde.2023.102115 -
Developmental Dynamics : An Official... Mar 2011The mammalian respiratory lineage, consisting of the trachea and lung, originates from the ventral foregut in an early embryo. Reciprocal signaling interactions between... (Review)
Review
The mammalian respiratory lineage, consisting of the trachea and lung, originates from the ventral foregut in an early embryo. Reciprocal signaling interactions between the foregut epithelium and its associated mesenchyme guide development of the respiratory endoderm, from a naive sheet of cells to multiple cell types that line a functional organ. This review synthesizes current understanding of the early events in respiratory system development, focusing on three main topics: (1) specification of the respiratory system as a distinct organ of the endoderm, (2) patterning and differentiation of the nascent respiratory epithelium along its proximal-distal axis, and (3) plasticity of the respiratory cells during the process of development. This review also highlights areas in need of further study, including determining how early endoderm cells rapidly switch their responses to the same signaling cues during development, and how the general proximal-distal pattern of the lung is converted to fine-scale organization of multiple cell types along this axis.
Topics: Animals; Body Patterning; Cell Differentiation; Endoderm; Gene Expression Regulation, Developmental; Humans; Respiratory System
PubMed: 21337460
DOI: 10.1002/dvdy.22504 -
Mechanisms of Development Apr 2007Endoderm differentiation and movements are of fundamental importance not only for subsequent morphogenesis of the digestive tract but also to enable normal patterning... (Review)
Review
Endoderm differentiation and movements are of fundamental importance not only for subsequent morphogenesis of the digestive tract but also to enable normal patterning and differentiation of mesoderm- and ectoderm-derived organs. This review defines the tissues that have been called endoderm in different species, their cellular origin and their movements. We take a comparative approach to ask how signaling pathways leading to embryonic and extraembryonic endoderm differentiation have emerged in different organisms, how they became integrated and point to specific gaps in our knowledge that would be worth filling. Lastly, we address whether the gastrulation movements that lead to endoderm internalization are coupled with its differentiation.
Topics: Animals; Biological Evolution; Cell Differentiation; Endoderm; Humans
PubMed: 17307341
DOI: 10.1016/j.mod.2007.01.001