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Bou-Rouphael J, Durand BC. T-Cell Factors as Transcriptional Inhibitors: Activities and Regulations in Vertebrate Head Development. Front Cell Dev Biol 2021; 9:784998. [PMID: 34901027 PMCID: PMC8651982 DOI: 10.3389/fcell.2021.784998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/28/2021] [Indexed: 11/22/2022] Open
Abstract
Since its first discovery in the late 90s, Wnt canonical signaling has been demonstrated to affect a large variety of neural developmental processes, including, but not limited to, embryonic axis formation, neural proliferation, fate determination, and maintenance of neural stem cells. For decades, studies have focused on the mechanisms controlling the activity of β-catenin, the sole mediator of Wnt transcriptional response. More recently, the spotlight of research is directed towards the last cascade component, the T-cell factor (TCF)/Lymphoid-Enhancer binding Factor (LEF), and more specifically, the TCF/LEF-mediated switch from transcriptional activation to repression, which in both embryonic blastomeres and mouse embryonic stem cells pushes the balance from pluri/multipotency towards differentiation. It has been long known that Groucho/Transducin-Like Enhancer of split (Gro/TLE) is the main co-repressor partner of TCF/LEF. More recently, other TCF/LEF-interacting partners have been identified, including the pro-neural BarH-Like 2 (BARHL2), which belongs to the evolutionary highly conserved family of homeodomain-containing transcription factors. This review describes the activities and regulatory modes of TCF/LEF as transcriptional repressors, with a specific focus on the functions of Barhl2 in vertebrate brain development. Specific attention is given to the transcriptional events leading to formation of the Organizer, as well as the roles and regulations of Wnt/β-catenin pathway in growth of the caudal forebrain. We present TCF/LEF activities in both embryonic and neural stem cells and discuss how alterations of this pathway could lead to tumors.
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Affiliation(s)
| | - Béatrice C. Durand
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Campus Pierre et Marie Curie, Paris, France
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Sena E, Bou-Rouphael J, Rocques N, Carron-Homo C, Durand BC. Mcl1 protein levels and Caspase-7 executioner protease control axial organizer cells survival. Dev Dyn 2020; 249:847-866. [PMID: 32141178 DOI: 10.1002/dvdy.169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 02/05/2020] [Accepted: 02/29/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Organizing centers are groups of specialized cells that secrete morphogens, thereby influencing development of their neighboring territories. Apoptosis is a form of programmed cell death reported to limit the size of organizers. Little is known about the identity of intracellular signals driving organizer cell death. Here we investigated in Xenopus the role of both the anti-apoptotic protein Myeloid-cell-leukemia 1 (Mcl1) and the cysteine proteases Caspase-3 and Caspase-7 in formation of the axial organizing center-the notochord-that derives from the Spemann organizer, and participates in the induction and patterning of the neuroepithelium. RESULTS We confirm a role for apoptosis in establishing the axial organizer in early neurula. We show that the expression pattern of mcl1 is coherent with a role for this gene in early notochord development. Using loss of function approaches, we demonstrate that Mcl1 depletion decreases neuroepithelium width and increases notochord cells apoptosis, a process that relies on Caspase-7, and not on Caspase-3, activity. Our data provide evidence that Mcl1 protein levels physiologically control notochord cells' survival and that Caspase-7 is the executioner protease in this developmental process. CONCLUSIONS Our study reveals new functions for Mcl1 and Caspase-7 in formation of the axial signalling center.
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Affiliation(s)
- Elena Sena
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France
| | - Johnny Bou-Rouphael
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
| | - Nathalie Rocques
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France
| | - Clémence Carron-Homo
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
| | - Béatrice C Durand
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France.,Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
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Sena E, Rocques N, Borday C, Amin HSM, Parain K, Sitbon D, Chesneau A, Durand BC. Barhl2 maintains T-cell factors as repressors, and thereby switches off the Wnt/β-Catenin response driving Spemann organizer formation. Development 2019; 146:dev.173112. [DOI: 10.1242/dev.173112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/11/2019] [Indexed: 12/19/2022]
Abstract
A hallmark of Wnt/β-Catenin signaling is the extreme diversity of its transcriptional response, which varies depending on cell and developmental context. What controls this diversity is poorly understood. In all cases, the switch from transcriptional repression to activation depends on a nuclear increase in β-Catenin, which detaches the transcription factor T-cell Factor-7 like 1 (Tcf7l1) bound to Groucho (Gro) transcriptional co-repressors from its DNA binding sites and transiently converts Tcf7/Lymphoid enhancer binding factor 1 (Lef1) into a transcriptional activator. One of the earliest and evolutionarily conserved functions of Wnt/β-Catenin signaling is the induction of the blastopore lip organizer. Here, we demonstrate that the evolutionarily conserved BarH-like homeobox-2 (Barhl2) protein stabilizes the Tcf7l1-Gro complex and maintains repressed expression of Tcf target genes by a mechanism that depends on histone deacetylase 1 (Hdac-1) activity. In this way, Barhl2 switches off the Wnt/β-Catenin-dependent early transcriptional response, thereby limiting the formation of the organizer in time and/or space. This study reveals a novel nuclear inhibitory mechanism of Wnt/Tcf signaling that switches off organizer fate determination.
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Affiliation(s)
- Elena Sena
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
| | - Nathalie Rocques
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
| | - Caroline Borday
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Harem Sabr Muhamad Amin
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 CNRS 8197, INSERM U1024 46 rue d'Ulm 75005, Paris F-75005, France
| | - Karine Parain
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - David Sitbon
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, Paris, France
| | - Albert Chesneau
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Béatrice C. Durand
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 CNRS 8197, INSERM U1024 46 rue d'Ulm 75005, Paris F-75005, France
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Kiecker C, Graham A, Logan M. Differential Cellular Responses to Hedgehog Signalling in Vertebrates-What is the Role of Competence? J Dev Biol 2016; 4:jdb4040036. [PMID: 29615599 PMCID: PMC5831800 DOI: 10.3390/jdb4040036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/24/2016] [Accepted: 12/01/2016] [Indexed: 12/21/2022] Open
Abstract
A surprisingly small number of signalling pathways generate a plethora of cellular responses ranging from the acquisition of multiple cell fates to proliferation, differentiation, morphogenesis and cell death. These diverse responses may be due to the dose-dependent activities of signalling factors, or to intrinsic differences in the response of cells to a given signal—a phenomenon called differential cellular competence. In this review, we focus on temporal and spatial differences in competence for Hedgehog (HH) signalling, a signalling pathway that is reiteratively employed in embryos and adult organisms. We discuss the upstream signals and mechanisms that may establish differential competence for HHs in a range of different tissues. We argue that the changing competence for HH signalling provides a four-dimensional framework for the interpretation of the signal that is essential for the emergence of functional anatomy. A number of diseases—including several types of cancer—are caused by malfunctions of the HH pathway. A better understanding of what provides differential competence for this signal may reveal HH-related disease mechanisms and equip us with more specific tools to manipulate HH signalling in the clinic.
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Affiliation(s)
- Clemens Kiecker
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Anthony Graham
- Department of Developmental Neurobiology, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
| | - Malcolm Logan
- Randall Division of Cell & Molecular Biophysics, King's College London, Hodgkin Building, Guy's Hospital Campus, London SE1 1UL, UK.
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Parish EV, Mason JO, Price DJ. Expression of Barhl2 and its relationship with Pax6 expression in the forebrain of the mouse embryo. BMC Neurosci 2016; 17:76. [PMID: 27887593 PMCID: PMC5124293 DOI: 10.1186/s12868-016-0311-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/16/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The transcription factor Barhl2 is an antiproneural transcription factor with roles in neuronal differentiation. The functions of its homologue in Drosophila development are better understood than its functions in mammalian brain development. Existing evidence suggests that its expression in the embryonic forebrain of the mouse is regional and may complement that of another transcription factor that is important for forebrain development, Pax6. The aim of this study is to provide a more detailed description of the Barhl2 expression pattern in the embryonic forebrain than is currently available, to relate its expression domains to those of Pax6 and to examine the effects of Pax6 loss on Barhl2 expression. RESULTS We found that Barhl2 is expressed in the developing diencephalon from the time of anterior neural tube closure. Its expression initially overlaps that of Pax6 in a central region of the alar diencephalon but over the following days their domains of expression become complementary in most forebrain regions. The exceptions are the thalamus and pretectum, where countergradients of Pax6 and Barhl2 expression are established by embryonic day 12.5, before overall Pax6 levels in these regions decline greatly while Barhl2 levels remain relatively high. We found that Barhl2 expression becomes upregulated in specifically the thalamus and pretectum in Pax6-null mice. CONCLUSIONS The region-specific expression pattern of Barhl2 makes it likely to be an important player in the development of region-specific differences in embryonic mouse forebrain. Repression of its expression in the thalamus and pretectum by Pax6 may be crucial for allowing proneural factors to promote normal neuronal differentiation in this region.
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Affiliation(s)
- Elisa V Parish
- Centre for Integrative Physiology, The University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
| | - John O Mason
- Centre for Integrative Physiology, The University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK
| | - David J Price
- Centre for Integrative Physiology, The University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.
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Sena E, Feistel K, Durand BC. An Evolutionarily Conserved Network Mediates Development of the zona limitans intrathalamica, a Sonic Hedgehog-Secreting Caudal Forebrain Signaling Center. J Dev Biol 2016; 4:jdb4040031. [PMID: 29615594 PMCID: PMC5831802 DOI: 10.3390/jdb4040031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 09/29/2016] [Accepted: 10/13/2016] [Indexed: 12/16/2022] Open
Abstract
Recent studies revealed new insights into the development of a unique caudal forebrain-signaling center: the zona limitans intrathalamica (zli). The zli is the last brain signaling center to form and the first forebrain compartment to be established. It is the only part of the dorsal neural tube expressing the morphogen Sonic Hedgehog (Shh) whose activity participates in the survival, growth and patterning of neuronal progenitor subpopulations within the thalamic complex. Here, we review the gene regulatory network of transcription factors and cis-regulatory elements that underlies formation of a shh-expressing delimitated domain in the anterior brain. We discuss evidence that this network predates the origin of chordates. We highlight the contribution of Shh, Wnt and Notch signaling to zli development and discuss implications for the fact that the morphogen Shh relies on primary cilia for signal transduction. The network that underlies zli development also contributes to thalamus induction, and to its patterning once the zli has been set up. We present an overview of the brain malformations possibly associated with developmental defects in this gene regulatory network (GRN).
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Affiliation(s)
- Elena Sena
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
| | - Kerstin Feistel
- Institute of Zoology, University of Hohenheim, Garbenstr. 30, 70593 Stuttgart, Germany.
| | - Béatrice C Durand
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
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7
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Barhl2 Determines the Early Patterning of the Diencephalon by Regulating Shh. Mol Neurobiol 2016; 54:4414-4420. [PMID: 27349434 DOI: 10.1007/s12035-016-0001-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
Abstract
The diencephalon is the primary relay network transmitting sensory information to the anterior forebrain. During development, distinct progenitor domains in the diencephalon give rise to the pretectum (p1), the thalamus and epithalamus (p2), and the prethalamus (p3), respectively. Shh plays a significant role in establishing the progenitor domains. However, the upstream events influencing the expression of Shh are largely unknown. Here, we show that Barhl2 homeobox gene is expressed in the p1 and p2 progenitor domains and the in zona limitans intrathalamica (ZLI) and regulates the acquisition of identity of progenitor cells in the developing diencephalon. Targeted deletion of Barhl2 results in the ablation of Shh expression in the dorsal portion of ZLI and causes thalamic p2 progenitors to take the fate of p1 progenitors and form pretectal neurons. Moreover, loss of Barhl2 leads to the absence of thalamocortical axon projections, the loss of habenular afferents and efferents, and a gross diminution of the pineal gland. Thus, by acting upstream of Shh signaling pathway, Barhl2 plays a crucial role in patterning the progenitor domains and establishing the positional identities of progenitor cells in the diencephalon.
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8
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Yamamizu K, Sharov AA, Piao Y, Amano M, Yu H, Nishiyama A, Dudekula DB, Schlessinger D, Ko MSH. Generation and gene expression profiling of 48 transcription-factor-inducible mouse embryonic stem cell lines. Sci Rep 2016; 6:25667. [PMID: 27150017 PMCID: PMC4858678 DOI: 10.1038/srep25667] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/21/2016] [Indexed: 11/22/2022] Open
Abstract
Mouse embryonic stem cells (ESCs) can differentiate into a wide range – and possibly all cell types in vitro, and thus provide an ideal platform to study systematically the action of transcription factors (TFs) in cell differentiation. Previously, we have generated and analyzed 137 TF-inducible mouse ESC lines. As an extension of this “NIA Mouse ESC Bank,” we generated and characterized 48 additional mouse ESC lines, in which single TFs in each line could be induced in a doxycycline-controllable manner. Together, with the previous ESC lines, the bank now comprises 185 TF-manipulable ESC lines (>10% of all mouse TFs). Global gene expression (transcriptome) profiling revealed that the induction of individual TFs in mouse ESCs for 48 hours shifts their transcriptomes toward specific differentiation fates (e.g., neural lineages by Myt1 Isl1, and St18; mesodermal lineages by Pitx1, Pitx2, Barhl2, and Lmx1a; white blood cells by Myb, Etv2, and Tbx6, and ovary by Pitx1, Pitx2, and Dmrtc2). These data also provide and lists of inferred target genes of each TF and possible functions of these TFs. The results demonstrate the utility of mouse ESC lines and their transcriptome data for understanding the mechanism of cell differentiation and the function of TFs.
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Affiliation(s)
- Kohei Yamamizu
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Alexei A Sharov
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Yulan Piao
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Misa Amano
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Hong Yu
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Akira Nishiyama
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Dawood B Dudekula
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - David Schlessinger
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Minoru S H Ko
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.,Department of Systems Medicine, Keio University School of Medicine, Tokyo 160-8582, Japan
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9
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Yao Y, Minor PJ, Zhao YT, Jeong Y, Pani AM, King AN, Symmons O, Gan L, Cardoso WV, Spitz F, Lowe CJ, Epstein DJ. Cis-regulatory architecture of a brain signaling center predates the origin of chordates. Nat Genet 2016; 48:575-80. [PMID: 27064252 PMCID: PMC4848136 DOI: 10.1038/ng.3542] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/11/2016] [Indexed: 12/13/2022]
Abstract
Genomic approaches have predicted hundreds of thousands of tissue-specific cis-regulatory sequences, but the determinants critical to their function and evolutionary history are mostly unknown. Here we systematically decode a set of brain enhancers active in the zona limitans intrathalamica (zli), a signaling center essential for vertebrate forebrain development via the secreted morphogen Sonic hedgehog (Shh). We apply a de novo motif analysis tool to identify six position-independent sequence motifs together with their cognate transcription factors that are essential for zli enhancer activity and Shh expression in the mouse embryo. Using knowledge of this regulatory lexicon, we discover new Shh zli enhancers in mice and a functionally equivalent element in hemichordates, indicating an ancient origin of the Shh zli regulatory network that predates the chordate phylum. These findings support a strategy for delineating functionally conserved enhancers in the absence of overt sequence homologies and over extensive evolutionary distances.
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Affiliation(s)
- Yao Yao
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Clinical Research Building 470, Philadelphia, PA 19104, USA
| | - Paul J. Minor
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Oceanview Blvd. Pacific Grove, CA 93950, USA
| | - Ying-Tao Zhao
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Clinical Research Building 470, Philadelphia, PA 19104, USA
| | - Yongsu Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University, Yongin-si 446-701, Republic of Korea
| | - Ariel M. Pani
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Oceanview Blvd. Pacific Grove, CA 93950, USA
| | - Anna N. King
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Clinical Research Building 470, Philadelphia, PA 19104, USA
| | - Orsolya Symmons
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Lin Gan
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Wellington V. Cardoso
- Columbia Center for Human Development, Department of Medicine, Pulmonary Allergy Critical Care, Columbia University Medical Center, New York, NY 10032, USA
| | - François Spitz
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Christopher J. Lowe
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Oceanview Blvd. Pacific Grove, CA 93950, USA
| | - Douglas J. Epstein
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Clinical Research Building 470, Philadelphia, PA 19104, USA
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Durand BC. Stem cell-like Xenopus Embryonic Explants to Study Early Neural Developmental Features In Vitro and In Vivo. J Vis Exp 2016:e53474. [PMID: 26863402 DOI: 10.3791/53474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Understanding the genetic programs underlying neural development is an important goal of developmental and stem cell biology. In the amphibian blastula, cells from the roof of the blastocoel are pluripotent. These cells can be isolated, and programmed to generate various tissues through manipulation of genes expression or induction by morphogens. In this manuscript protocols are described for the use of Xenopus laevis blastocoel roof explants as an assay system to investigate key in vivo and in vitro features of early neural development. These protocols allow the investigation of fate acquisition, cell migration behaviors, and cell autonomous and non-autonomous properties. The blastocoel roof explants can be cultured in a serum-free defined medium and grafted into host embryos. This transplantation into an embryo allows the investigation of the long-term lineage commitment, the inductive properties, and the behavior of transplanted cells in vivo. These assays can be exploited to investigate molecular mechanisms, cellular processes and gene regulatory networks underlying neural development. In the context of regenerative medicine, these assays provide a means to generate neural-derived cell types in vitro that could be used in drug screening.
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Affiliation(s)
- Beatrice C Durand
- Institut Curie; UMR 3387, CNRS; PSL Research University; Université Paris-Sud;
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Juraver-Geslin HA, Durand BC. Early development of the neural plate: new roles for apoptosis and for one of its main effectors caspase-3. Genesis 2015; 53:203-24. [PMID: 25619400 DOI: 10.1002/dvg.22844] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/07/2015] [Indexed: 12/12/2022]
Abstract
Despite its tremendous complexity, the vertebrate nervous system emerges from a homogenous layer of neuroepithelial cells, the neural plate. Its formation relies on the time- and space-controlled progression of developmental programs. Apoptosis is a biological process that removes superfluous and potentially dangerous cells and is implemented through the activation of a molecular pathway conserved during evolution. Apoptosis and an unconventional function of one of its main effectors, caspase-3, contribute to the patterning and growth of the neuroepithelium. Little is known about the intrinsic and extrinsic cues controlling activities of the apoptotic machinery during development. The BarH-like (Barhl) proteins are homeodomain-containing transcription factors. The observations in Caenorhabditis elegans, Xenopus, and mice document that Barhl proteins act in cell survival and as cell type-specific regulators of a caspase-3 function that limits neural progenitor proliferation. In this review, we discuss the roles and regulatory modes of the apoptotic machinery in the development of the neural plate. We focus on the Barhl2, the Sonic Hedgehog, and the Wnt pathways and their activities in neural progenitor survival and proliferation.
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Affiliation(s)
- Hugo A Juraver-Geslin
- Department of Basic Science, Craniofacial Biology, College of Dentistry, New York University, New York, New York
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