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FEBS Letters Dec 2019The haematopoietic system is established during embryonic life through a series of developmental steps that culminates with the generation of haematopoietic stem cells.... (Review)
Review
The haematopoietic system is established during embryonic life through a series of developmental steps that culminates with the generation of haematopoietic stem cells. Characterisation of the transcriptional network that regulates blood cell emergence has led to the identification of transcription factors essential for this process. Among the many factors wired within this complex regulatory network, ETV2, SCL and RUNX1 are the central components. All three factors are absolutely required for blood cell generation, each one controlling a precise step of specification from the mesoderm germ layer to fully functional blood progenitors. Insight into the transcriptional control of blood cell emergence has been used for devising protocols to generate blood cells de novo, either through reprogramming of somatic cells or through forward programming of pluripotent stem cells. Interestingly, the physiological process of blood cell generation and its laboratory-engineered counterpart have very little in common.
Topics: Blood Cells; Cell Differentiation; Cellular Reprogramming; Core Binding Factor Alpha 2 Subunit; Hematopoietic Stem Cells; Humans; Mesoderm; Pluripotent Stem Cells; T-Cell Acute Lymphocytic Leukemia Protein 1; Transcription Factors; Transcriptional Activation
PubMed: 31432499
DOI: 10.1002/1873-3468.13585 -
Cells & Development Sep 2021Early in animal development many cells are conditionally specified based on observations that those cells can be directed toward alternate fates. The endomesoderm is so... (Review)
Review
Early in animal development many cells are conditionally specified based on observations that those cells can be directed toward alternate fates. The endomesoderm is so named because early specification produces cells that often have been observed to simultaneously express both early endoderm and mesoderm transcription factors. Experiments with these cells demonstrate that their progeny can directed entirely toward endoderm or mesoderm, whereas normally they establish both germ layers. This review examines the mechanisms that initiate the conditional endomesoderm state, its metastability, and the mechanisms that resolve that state into definitive endoderm and mesoderm.
Topics: Animals; Body Patterning; Endoderm; Humans; Mesoderm; Models, Biological; Sea Urchins; Signal Transduction
PubMed: 34245941
DOI: 10.1016/j.cdev.2021.203716 -
Cells & Development Dec 2021Vertebrate segmentation, the process that generates a regular arrangement of somites and thereby establishes the pattern of the adult body and of the musculoskeletal and... (Review)
Review
Vertebrate segmentation, the process that generates a regular arrangement of somites and thereby establishes the pattern of the adult body and of the musculoskeletal and peripheral nervous systems, was noticed many centuries ago. In the last few decades, there has been renewed interest in the process and especially in the molecular mechanisms that might account for its regularity and other spatial-temporal properties. Several models have been proposed but surprisingly, most of these do not provide clear links between the molecular mechanisms and the cell behaviours that generate the segmental pattern. Here we present a short survey of our current knowledge about the cellular aspects of vertebrate segmentation and the similarities and differences between different vertebrate groups in how they achieve their metameric pattern. Taking these variations into account should help to assess each of the models more appropriately.
Topics: Animals; Body Patterning; Somites; Vertebrates
PubMed: 34391979
DOI: 10.1016/j.cdev.2021.203732 -
Mechanisms of Development Sep 2020Among the basally branching metazoans, cnidarians display well-defined gastrulation processes leading to a diploblastic body plan, consisting of an endodermal and an... (Review)
Review
Among the basally branching metazoans, cnidarians display well-defined gastrulation processes leading to a diploblastic body plan, consisting of an endodermal and an ectodermal cell layer. As the outgroup to all Bilateria, cnidarians are an interesting group to investigate ancestral developmental mechanisms. Interestingly, all known gastrulation mechanisms known in Bilateria are already found in different species of Cnidaria. Here I review the morphogenetic processes found in different Cnidaria and focus on the investigation of the cellular and molecular mechanisms in the sea anemone Nematostella vectensis, which has been a major model organism among cnidarians for evolutionary developmental biology. Many of the genes involved in germ layer specification and morphogenetic processes in Bilateria are also found active during gastrulation of Nematostella and other cnidarians, suggesting an ancestral role of this process. The molecular analyses indicate a tight link between gastrulation and axis patterning processes by Wnt and FGF signaling. Interestingly, the endodermal layer displays many features of the mesodermal layer in Bilateria, while the pharyngeal ectoderm has an endodermal expression profile. Comparative analyses as well as experimental studies using embryonic aggregates suggest that minor differences in the gene regulatory networks allow the embryo to transition relatively easily from one mode of gastrulation to another.
Topics: Animals; Body Patterning; Cnidaria; Ectoderm; Embryo, Nonmammalian; Endoderm; Gastrulation; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Germ Layers; Mesoderm; Sea Anemones; Signal Transduction
PubMed: 32603823
DOI: 10.1016/j.mod.2020.103628 -
Nature Communications Jun 2023While the generation of many lineages from pluripotent stem cells has resulted in basic discoveries and clinical trials, the derivation of tissue-specific mesenchyme via...
While the generation of many lineages from pluripotent stem cells has resulted in basic discoveries and clinical trials, the derivation of tissue-specific mesenchyme via directed differentiation has markedly lagged. The derivation of lung-specific mesenchyme is particularly important since this tissue plays crucial roles in lung development and disease. Here we generate a mouse induced pluripotent stem cell (iPSC) line carrying a lung-specific mesenchymal reporter/lineage tracer. We identify the pathways (RA and Shh) necessary to specify lung mesenchyme and find that mouse iPSC-derived lung mesenchyme (iLM) expresses key molecular and functional features of primary developing lung mesenchyme. iLM recombined with engineered lung epithelial progenitors self-organizes into 3D organoids with juxtaposed layers of epithelium and mesenchyme. Co-culture increases yield of lung epithelial progenitors and impacts epithelial and mesenchymal differentiation programs, suggesting functional crosstalk. Our iPSC-derived population thus provides an inexhaustible source of cells for studying lung development, modeling diseases, and developing therapeutics.
Topics: Animals; Mice; Pluripotent Stem Cells; Cell Differentiation; Induced Pluripotent Stem Cells; Thorax; Mesoderm
PubMed: 37311756
DOI: 10.1038/s41467-023-39099-9 -
Current Topics in Developmental Biology 2020Gastrulation is the period of development when the three germ layers, mesoderm, endoderm and ectoderm, are not only formed, but also shaped into a rudimentary body plan.... (Review)
Review
Gastrulation is the period of development when the three germ layers, mesoderm, endoderm and ectoderm, are not only formed, but also shaped into a rudimentary body plan. An elongated anteroposterior (AP) axis is a key feature of all vertebrate body plans, and it forms during gastrulation through the highly conserved morphogenetic mechanism of convergence & extension (C&E). As the name suggests, this process requires that cells within each germ layer converge toward the dorsal midline to narrow the tissue in the mediolateral (ML) dimension and concomitantly extend it in the AP dimension. In a number of vertebrate species, C&E is driven primarily by mediolateral intercalation behavior (MIB), during which cells elongate, align, and extend protrusions in the ML direction and interdigitate between their neighbors. MIB is only one of many complex cellular mechanisms that contributes to C&E in zebrafish embryos, however, where a combination of individual cell migration, collective migration, random walk, radial intercalation, epiboly movements, and MIB all act together to shape the nascent germ layers. Each of these diverse cell movements is driven by a distinct suite of dynamic cellular properties/activities, such as actin-rich protrusions, myosin contractility, and blebbing. Here, we discuss the spatiotemporal patterns of cellular behaviors underlying C&E gastrulation movements within each germ layer of zebrafish embryos. These behaviors must be coordinated with the embryonic axes, and we highlight the roles of Planar Cell Polarity (PCP) in orienting and BMP signaling in patterning C&E cell behaviors with respect to the AP and dorsoventral axes. Finally, we address the role of GPCR signaling, extracellular matrix, and mechanical signals in coordination of C&E movements between adjacent germ layers.
Topics: Animals; Body Patterning; Embryo, Nonmammalian; Gastrulation; Gene Expression Regulation, Developmental; Germ Layers; Morphogenesis; Signal Transduction; Zebrafish; Zebrafish Proteins
PubMed: 31959296
DOI: 10.1016/bs.ctdb.2019.08.001 -
Trends in Cell Biology Feb 2022The endoderm, one of the three primary germ layers, gives rise to lung, liver, stomach, intestine, colon, pancreas, bladder, and thyroid. These endoderm-originated... (Review)
Review
The endoderm, one of the three primary germ layers, gives rise to lung, liver, stomach, intestine, colon, pancreas, bladder, and thyroid. These endoderm-originated organs are subject to many life-threatening diseases. However, primary cells/tissues from endodermal organs are often difficult to grow in vitro. Human pluripotent stem cells (hPSCs), therefore, hold great promise for generating endodermal cells and their derivatives for the development of new therapeutics against these human diseases. Although a wealth of research has provided crucial information on the mechanisms underlying endoderm differentiation from hPSCs, increasing evidence has shown that metabolism, in connection with epigenetics, actively regulates endoderm differentiation in addition to the conventional endoderm inducing signals. Here we review recent advances in metabolic and epigenetic regulation of endoderm differentiation.
Topics: Cell Differentiation; Endoderm; Epigenesis, Genetic; Humans; Pluripotent Stem Cells
PubMed: 34607773
DOI: 10.1016/j.tcb.2021.09.002 -
Cells Aug 2021Fibroblast growth factors (FGFs) comprise a large family of growth factors, regulating diverse biological processes including cell proliferation, migration, and... (Review)
Review
Fibroblast growth factors (FGFs) comprise a large family of growth factors, regulating diverse biological processes including cell proliferation, migration, and differentiation. Each FGF binds to a set of FGF receptors to initiate certain intracellular signaling molecules. Accumulated evidence suggests that in early development and adult state of vertebrates, FGFs also play exclusive and context dependent roles. Although FGFs have been the focus of research for therapeutic approaches in cancer, cardiovascular disease, and metabolic syndrome, in this review, we mainly focused on their role in germ layer specification and axis patterning during early vertebrate embryogenesis. We discussed the functional roles of FGFs and their interacting partners as part of the gene regulatory network for germ layer specification, dorsal-ventral (DV), and anterior-posterior (AP) patterning. Finally, we briefly reviewed the regulatory molecules and pharmacological agents discovered that may allow modulation of FGF signaling in research.
Topics: Animals; Fibroblast Growth Factors; Gene Expression Regulation, Developmental; Germ Layers; Humans; Models, Biological; Protein Binding; Receptors, Fibroblast Growth Factor; Signal Transduction; Vertebrates
PubMed: 34440915
DOI: 10.3390/cells10082148 -
Cells & Development Dec 2021Early in animal development many cells are conditionally specified based on observations that those cells can be directed toward alternate fates. The endomesoderm is so... (Review)
Review
Early in animal development many cells are conditionally specified based on observations that those cells can be directed toward alternate fates. The endomesoderm is so named because early specification produces cells that often have been observed to simultaneously express both early endoderm and mesoderm transcription factors. Experiments with these cells demonstrate that their progeny can directed entirely toward endoderm or mesoderm, whereas normally they establish both germ layers. This review examines the mechanisms that initiate the conditional endomesoderm state, its metastability, and the mechanisms that resolve that state into definitive endoderm and mesoderm.
Topics: Animals; Embryo, Nonmammalian; Endoderm; Mesoderm; Sea Urchins; Signal Transduction
PubMed: 34610899
DOI: 10.1016/j.cdev.2021.203731 -
Birth Defects Research Nov 2020During craniofacial development, defective growth and fusion of the upper lip and/or palate can cause orofacial clefts (OFCs), which are among the most common structural... (Review)
Review
During craniofacial development, defective growth and fusion of the upper lip and/or palate can cause orofacial clefts (OFCs), which are among the most common structural birth defects in humans. The developmental basis of OFCs includes morphogenesis of the upper lip, primary palate, secondary palate, and other orofacial structures, each consisting of diverse cell types originating from all three germ layers: the ectoderm, mesoderm, and endoderm. Cranial neural crest cells and orofacial epithelial cells are two major cell types that interact with various cell lineages and play key roles in orofacial development. The cellular basis of OFCs involves defective execution in any one or several of the following processes: neural crest induction, epithelial-mesenchymal transition, migration, proliferation, differentiation, apoptosis, primary cilia formation and its signaling transduction, epithelial seam formation and disappearance, periderm formation and peeling, convergence and extrusion of palatal epithelial seam cells, cell adhesion, cytoskeleton dynamics, and extracellular matrix function. The latest cellular and developmental findings may provide a basis for better understanding of the underlying genetic, epigenetic, environmental, and molecular mechanisms of OFCs.
Topics: Cleft Lip; Cleft Palate; Humans; Mesoderm; Morphogenesis
PubMed: 32725806
DOI: 10.1002/bdr2.1768