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Abe K, Shimada A, Tayama S, Nishikawa H, Kaneko T, Tsuda S, Karaiwa A, Matsui T, Ishitani T, Takeda H. Horizontal Boundary Cells, a Special Group of Somitic Cells, Play Crucial Roles in the Formation of Dorsoventral Compartments in Teleost Somite. Cell Rep 2020; 27:928-939.e4. [PMID: 30995487 DOI: 10.1016/j.celrep.2019.03.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/27/2019] [Accepted: 03/18/2019] [Indexed: 12/18/2022] Open
Abstract
Establishment of robust gene expression boundary is crucial for creating elaborate morphology during development. However, mechanisms underlying boundary formation have been extensively studied only in a few model systems. We examined the establishment of zic1/zic4-expression boundary demarcating dorsoventral boundary of the entire trunk of medaka fish (Oryzias latipes) and identified a subgroup of dermomyotomal cells called horizontal boundary cells (HBCs) as crucial players for the boundary formation. Embryological and genetic analyses demonstrated that HBCs play crucial roles in the two major events of the process, i.e., refinement and maintenance. In the refinement, HBCs could serve as a chemical barrier against Wnts from the neural tube by expressing Hhip. At later stages, HBCs participate in the maintenance of the boundary by differentiating into the horizontal myoseptum physically inhibiting cell mixing across the boundary. These findings reveal the mechanisms underlying the dorsoventral boundary in the teleost trunk by specialized boundary cells.
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Affiliation(s)
- Kota Abe
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi 371-8512, Japan
| | - Atsuko Shimada
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Sayaka Tayama
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hotaka Nishikawa
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takuya Kaneko
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Sachiko Tsuda
- Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan; Saitama University Brain Science Institute, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan; Research and Development Bureau, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan
| | - Akari Karaiwa
- Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Takaaki Matsui
- Gene Regulation Research, Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan
| | - Tohru Ishitani
- Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi 371-8512, Japan
| | - Hiroyuki Takeda
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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2
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Holtz AM, Griffiths SC, Davis SJ, Bishop B, Siebold C, Allen BL. Secreted HHIP1 interacts with heparan sulfate and regulates Hedgehog ligand localization and function. J Cell Biol 2015; 209:739-57. [PMID: 26056142 PMCID: PMC4460154 DOI: 10.1083/jcb.201411024] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/24/2015] [Indexed: 01/21/2023] Open
Abstract
Vertebrate Hedgehog (HH) signaling is controlled by several ligand-binding antagonists including Patched-1 (PTCH1), PTCH2, and HH-interacting protein 1 (HHIP1), whose collective action is essential for proper HH pathway activity. However, the molecular mechanisms used by these inhibitors remain poorly understood. In this paper, we investigated the mechanisms underlying HHIP1 antagonism of HH signaling. Strikingly, we found evidence that HHIP1 non-cell-autonomously inhibits HH-dependent neural progenitor patterning and proliferation. Furthermore, this non-cell-autonomous antagonism of HH signaling results from the secretion of HHIP1 that is modulated by cell type-specific interactions with heparan sulfate (HS). These interactions are mediated by an HS-binding motif in the cysteine-rich domain of HHIP1 that is required for its localization to the neuroepithelial basement membrane (BM) to effectively antagonize HH pathway function. Our data also suggest that endogenous, secreted HHIP1 localization to HS-containing BMs regulates HH ligand distribution. Overall, the secreted activity of HHIP1 represents a novel mechanism to regulate HH ligand localization and function during embryogenesis.
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Affiliation(s)
- Alexander M Holtz
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109 Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109 Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109
| | - Samuel C Griffiths
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, England, UK
| | - Samantha J Davis
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
| | - Benjamin Bishop
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, England, UK
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, England, UK
| | - Benjamin L Allen
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109
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3
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Pfirrmann T, Villavicencio-Lorini P, Subudhi AK, Menssen R, Wolf DH, Hollemann T. RMND5 from Xenopus laevis is an E3 ubiquitin-ligase and functions in early embryonic forebrain development. PLoS One 2015; 10:e0120342. [PMID: 25793641 PMCID: PMC4368662 DOI: 10.1371/journal.pone.0120342] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 01/22/2015] [Indexed: 12/19/2022] Open
Abstract
In Saccharomyces cerevisiae the Gid-complex functions as an ubiquitin-ligase complex that regulates the metabolic switch between glycolysis and gluconeogenesis. In higher organisms six conserved Gid proteins form the CTLH protein-complex with unknown function. Here we show that Rmnd5, the Gid2 orthologue from Xenopus laevis, is an ubiquitin-ligase embedded in a high molecular weight complex. Expression of rmnd5 is strongest in neuronal ectoderm, prospective brain, eyes and ciliated cells of the skin and its suppression results in malformations of the fore- and midbrain. We therefore suggest that Xenopus laevis Rmnd5, as a subunit of the CTLH complex, is a ubiquitin-ligase targeting an unknown factor for polyubiquitination and subsequent proteasomal degradation for proper fore- and midbrain development.
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Affiliation(s)
- Thorsten Pfirrmann
- Martin-Luther University Halle-Wittenberg, Institute of Physiological Chemistry, Halle, Germany
- * E-mail:
| | | | - Abinash K. Subudhi
- Martin-Luther University Halle-Wittenberg, Institute of Physiological Chemistry, Halle, Germany
| | - Ruth Menssen
- University of Stuttgart, Institute of Biochemistry, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Dieter H. Wolf
- University of Stuttgart, Institute of Biochemistry, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Thomas Hollemann
- Martin-Luther University Halle-Wittenberg, Institute of Physiological Chemistry, Halle, Germany
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4
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Pfirrmann T, Emmerich D, Ruokonen P, Quandt D, Buchen R, Fischer-Zirnsak B, Hecht J, Krawitz P, Meyer P, Klopocki E, Stricker S, Lausch E, Seliger B, Hollemann T, Reinhard T, Auw-Haedrich C, Zabel B, Hoffmann K, Villavicencio-Lorini P. Molecular mechanism of CHRDL1-mediated X-linked megalocornea in humans and in Xenopus model. Hum Mol Genet 2015; 24:3119-32. [DOI: 10.1093/hmg/ddv063] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/13/2015] [Indexed: 11/14/2022] Open
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5
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Pera EM, Acosta H, Gouignard N, Climent M. Whole-Mount In Situ Hybridization and Immunohistochemistry in Xenopus Embryos. IN SITU HYBRIDIZATION METHODS 2015. [DOI: 10.1007/978-1-4939-2303-8_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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6
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Choi JJY, Ting CT, Trogrlic L, Milevski SV, Familari M, Martinez G, de Iongh RU. A role for smoothened during murine lens and cornea development. PLoS One 2014; 9:e108037. [PMID: 25268479 PMCID: PMC4182430 DOI: 10.1371/journal.pone.0108037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 08/25/2014] [Indexed: 01/07/2023] Open
Abstract
Various studies suggest that Hedgehog (Hh) signalling plays roles in human and zebrafish ocular development. Recent studies (Kerr et al., Invest Ophthalmol Vis Sci. 2012; 53, 3316–30) showed that conditionally activating Hh signals promotes murine lens epithelial cell proliferation and disrupts fibre differentiation. In this study we examined the expression of the Hh pathway and the requirement for the Smoothened gene in murine lens development. Expression of Hh pathway components in developing lens was examined by RT-PCR, immunofluorescence and in situ hybridisation. The requirement of Smo in lens development was determined by conditional loss-of-function mutations, using LeCre and MLR10 Cre transgenic mice. The phenotype of mutant mice was examined by immunofluorescence for various markers of cell cycle, lens and cornea differentiation. Hh pathway components (Ptch1, Smo, Gli2, Gli3) were detected in lens epithelium from E12.5. Gli2 was particularly localised to mitotic nuclei and, at E13.5, Gli3 exhibited a shift from cytosol to nucleus, suggesting distinct roles for these transcription factors. Conditional deletion of Smo, from ∼E12.5 (MLR10 Cre) did not affect ocular development, whereas deletion from ∼E9.5 (LeCre) resulted in lens and corneal defects from E14.5. Mutant lenses were smaller and showed normal expression of p57Kip2, c-Maf, E-cadherin and Pax6, reduced expression of FoxE3 and Ptch1 and decreased nuclear Hes1. There was normal G1-S phase but decreased G2-M phase transition at E16.5 and epithelial cell death from E14.5-E16.5. Mutant corneas were thicker due to aberrant migration of Nrp2+ cells from the extraocular mesenchyme, resulting in delayed corneal endothelial but normal epithelial differentiation. These results indicate the Hh pathway is required during a discrete period (E9.5–E12.5) in lens development to regulate lens epithelial cell proliferation, survival and FoxE3 expression. Defective corneal development occurs secondary to defects in lens and appears to be due to defective migration of peri-ocular Nrp2+ neural crest/mesenchymal cells.
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MESH Headings
- Animals
- Animals, Newborn
- Cell Cycle
- Cell Movement
- Cornea/growth & development
- Cornea/metabolism
- Cornea/pathology
- Embryo, Mammalian
- Endothelial Cells/metabolism
- Endothelial Cells/pathology
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Forkhead Transcription Factors/genetics
- Forkhead Transcription Factors/metabolism
- Gene Expression Regulation, Developmental
- Integrases/genetics
- Integrases/metabolism
- Kruppel-Like Transcription Factors/genetics
- Kruppel-Like Transcription Factors/metabolism
- Lens, Crystalline/growth & development
- Lens, Crystalline/metabolism
- Lens, Crystalline/pathology
- Membrane Proteins
- Mesenchymal Stem Cells/metabolism
- Mesenchymal Stem Cells/pathology
- Mice
- Mice, Transgenic
- Morphogenesis
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neuropilin-2/genetics
- Neuropilin-2/metabolism
- Patched Receptors
- Patched-1 Receptor
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction
- Smoothened Receptor
- Zebrafish Proteins
- Zinc Finger Protein Gli2
- Zinc Finger Protein Gli3
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Affiliation(s)
- Janet J. Y. Choi
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
| | - Chao-Tung Ting
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
| | - Lidia Trogrlic
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
| | - Stefan V. Milevski
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
| | - Mary Familari
- Department of Zoology, University of Melbourne, Parkville, Australia
| | - Gemma Martinez
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
| | - Robb U de Iongh
- Ocular Development Laboratory, Anatomy & Neuroscience, University of Melbourne, Parkville, Australia
- * E-mail:
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7
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Kuo MW, Lou SW, Chung BC. Hedgehog-PKA signaling and gnrh3 regulate the development of zebrafish gnrh3 neurons. PLoS One 2014; 9:e95545. [PMID: 24879419 PMCID: PMC4039432 DOI: 10.1371/journal.pone.0095545] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 03/28/2014] [Indexed: 01/21/2023] Open
Abstract
GnRH neurons secrete GnRH that controls the development of the reproduction system. Despite many studies, the signals controlling the development of GnRH neurons from its progenitors have not been fully established. To understand the development of GnRH neurons, we examined the development of gnrh3-expressing cells using a transgenic zebrafish line that expresses green fluorescent protein (GFP) and LacZ driven by the gnrh3 promoter. GFP and LacZ expression recapitulated that of gnrh3 in the olfactory region, olfactory bulb and telencephalon. Depletion of gnrh3 by morpholinos led to a reduction of GFP- and gnrh3-expressing cells, while over-expression of gnrh3 mRNA increased the number of these cells. This result indicates a positive feed-forward regulation of gnrh3 cells by gnrh3. The gnrh3 cells were absent in embryos that lack Hedgehog signaling, but their numbers were increased in embryos overexpressing shhb. We manipulated the amounts of kinase that antagonizes the Hedgehog signaling pathway, protein kinase A (PKA), by treating embryos with PKA activator forskolin or by injecting mRNAs encoding its constitutively active catalytic subunit (PKA*) and dominant negative regulatory subunit (PKI) into zebrafish embryos. PKA* misexpression or forskolin treatment decreased GFP cell numbers, while PKI misexpression led to ectopic production of GFP cells. Our data indicate that the Hedgehog-PKA pathway participates in the development of gnrh3-expressing neurons during embryogenesis.
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Affiliation(s)
- Ming-Wei Kuo
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan
| | - Show-Wan Lou
- Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan
| | - Bon-chu Chung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail:
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8
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Differential BMP signaling controls formation and differentiation of multipotent preplacodal ectoderm progenitors from human embryonic stem cells. Dev Biol 2013; 379:208-20. [PMID: 23643939 DOI: 10.1016/j.ydbio.2013.04.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 04/05/2013] [Accepted: 04/22/2013] [Indexed: 01/08/2023]
Abstract
Sensory and endoneurocrine tissues as diverse as the lens, the olfactory epithelium, the inner ear, the cranial sensory ganglia, and the anterior pituitary arise from a common pool of progenitors in the preplacodal ectoderm (PPE). Around late gastrulation, the PPE forms at the border surrounding the anterior neural plate, and expresses a unique set of evolutionarily conserved transcription regulators including Six1, Eya 1 and Eya2. Here, we describe the first report to generate and characterize the SIX1(+) PPE cells from human embryonic stem (ES) cells by adherent differentiation. Before forming PPE cells, differentiating cultures first expressed the non-neural ectoderm specific transcriptional factors TFAP2A, GATA2, GATA3, DLX3, and DLX5, which are crucial in establishing the PPE competence. We demonstrated that bone morphogenetic protein (BMP) activity plays a transient but essential role in inducing expression of these PPE competence factors and eventually the PPE cells. Interestingly, we found that attenuating BMP signaling after establishing the competence state induces anterior placode precursors. By manipulating BMP and hedgehog signaling pathways, we further differentiate these precursors into restricted lineages including the lens placode and the oral ectoderm (pituitary precursor) cells. Finally, we also show that sensory neurons can be generated from human PPE cells, demonstrating the multipotency of the human ES-derived PPE cells.
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9
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Grocott T, Tambalo M, Streit A. The peripheral sensory nervous system in the vertebrate head: a gene regulatory perspective. Dev Biol 2012; 370:3-23. [PMID: 22790010 DOI: 10.1016/j.ydbio.2012.06.028] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 02/06/2023]
Abstract
In the vertebrate head, crucial parts of the sense organs and sensory ganglia develop from special regions, the cranial placodes. Despite their cellular and functional diversity, they arise from a common field of multipotent progenitors and acquire distinct identity later under the influence of local signalling. Here we present the gene regulatory network that summarises our current understanding of how sensory cells are specified, how they become different from other ectodermal derivatives and how they begin to diversify to generate placodes with different identities. This analysis reveals how sequential activation of sets of transcription factors subdivides the ectoderm over time into smaller domains of progenitors for the central nervous system, neural crest, epidermis and sensory placodes. Within this hierarchy the timing of signalling and developmental history of each cell population is of critical importance to determine the ultimate outcome. A reoccurring theme is that local signals set up broad gene expression domains, which are further refined by mutual repression between different transcription factors. The Six and Eya network lies at the heart of sensory progenitor specification. In a positive feedback loop these factors perpetuate their own expression thus stabilising pre-placodal fate, while simultaneously repressing neural and neural crest specific factors. Downstream of the Six and Eya cassette, Pax genes in combination with other factors begin to impart regional identity to placode progenitors. While our review highlights the wealth of information available, it also points to the lack information on the cis-regulatory mechanisms that control placode specification and of how the repeated use of signalling input is integrated.
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Affiliation(s)
- Timothy Grocott
- Department of Craniofacial Development and Stem Cell Biology, King's College London, Guy's Tower Wing, Floor 27, London SE1 9RT, UK
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10
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Kerr CL, Huang J, Williams T, West-Mays JA. Activation of the hedgehog signaling pathway in the developing lens stimulates ectopic FoxE3 expression and disruption in fiber cell differentiation. Invest Ophthalmol Vis Sci 2012; 53:3316-30. [PMID: 22491411 DOI: 10.1167/iovs.12-9595] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The signaling pathways and transcriptional effectors responsible for directing mammalian lens development provide key regulatory molecules that can inform our understanding of human eye defects. The hedgehog genes encode extracellular signaling proteins responsible for patterning and tissue formation during embryogenesis. Signal transduction of this pathway is mediated through activation of the transmembrane proteins smoothened and patched, stimulating downstream signaling resulting in the activation or repression of hedgehog target genes. Hedgehog signaling is implicated in eye development, and defects in hedgehog signaling components have been shown to result in defects of the retina, iris, and lens. METHODS We assessed the consequences of constitutive hedgehog signaling in the developing mouse lens using Cre-LoxP technology to express the conditional M2 smoothened allele in the embryonic head and lens ectoderm. RESULTS Although initial lens development appeared normal, morphological defects were apparent by E12.5 and became more significant at later stages of embryogenesis. Altered lens morphology correlated with ectopic expression of FoxE3, which encodes a critical gene required for human and mouse lens development. Later, inappropriate expression of the epithelial marker Pax6, and as well as fiber cell markers c-maf and Prox1 also occurred, indicating a failure of appropriate lens fiber cell differentiation accompanied by altered lens cell proliferation and cell death. CONCLUSIONS Our findings demonstrate that the ectopic activation of downstream effectors of the hedgehog signaling pathway in the mouse lens disrupts normal fiber cell differentiation by a mechanism consistent with a sustained epithelial cellular developmental program driven by FoxE3.
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Affiliation(s)
- Christine L Kerr
- Department of Pathology and Molecular Medicine, McMaster University Health Sciences Centre, Hamilton, Ontario, Canada
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11
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Abstract
Many of the features that distinguish the vertebrates from other chordates are found in the head. Prominent amongst these differences are the paired sense organs and associated cranial ganglia. Significantly, these structures are derived developmentally from the ectodermal placodes. It has therefore been proposed that the emergence of the ectodermal placodes was concomitant with and central to the evolution of the vertebrates. More recent studies, however, indicate forerunners of the ectodermal placodes can be readily identified outside the vertebrates, particularly in urochordates. Thus the evolutionary history of the ectodermal placodes is deeper and more complex than was previously appreciated with the full repertoire of vertebrate ectodermal placodes, and their derivatives, being assembled over a protracted period rather than arising collectively with the vertebrates.
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Affiliation(s)
- Anthony Graham
- MRC Centre for Developmental Neurobiology, King's College London, London, UK
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12
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Min TH, Kriebel M, Hou S, Pera EM. The dual regulator Sufu integrates Hedgehog and Wnt signals in the early Xenopus embryo. Dev Biol 2011; 358:262-76. [PMID: 21839734 DOI: 10.1016/j.ydbio.2011.07.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 07/01/2011] [Accepted: 07/28/2011] [Indexed: 12/14/2022]
Abstract
Hedgehog (Hh) and Wnt proteins are important signals implicated in several aspects of embryonic development, including the early development of the central nervous system. We found that Xenopus Suppressor-of-fused (XSufu) affects neural induction and patterning by regulating the Hh/Gli and Wnt/β-catenin pathways. Microinjection of XSufu mRNA induced expansion of the epidermis at the expense of neural plate tissue and caused enlargement of the eyes. An antisense morpholino oligonucleotide against XSufu had the opposite effect. Interestingly, both gain- and loss-of-function experiments resulted in a posterior shift of brain markers, suggesting a biphasic effect of XSufu on anteroposterior patterning. XSufu blocked early Wnt/β-catenin signaling, as indicated by the suppression of XWnt8-induced secondary axis formation in mRNA-injected embryos, and activation of Wnt target genes in XSufu-MO-injected ectodermal explants. We show that XSufu binds to XGli1 and Xβ-catenin. In Xenopus embryos and mouse embryonic fibroblasts, Gli1 inhibits Wnt signaling under overexpression of β-catenin, whereas β-catenin stimulates Hh signaling under overexpression of Gli1. Notably, endogenous Sufu is critically involved in this crosstalk. The results suggest that XSufu may act as a common regulator of Hh and Wnt signaling and contribute to intertwining the two pathways.
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Affiliation(s)
- Tan H Min
- Stem Cell Center, Lund University, 221 84 Lund, Sweden
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13
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Gunhaga L. The lens: a classical model of embryonic induction providing new insights into cell determination in early development. Philos Trans R Soc Lond B Biol Sci 2011; 366:1193-203. [PMID: 21402580 DOI: 10.1098/rstb.2010.0175] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The lens was the first tissue in which the concept of embryonic induction was demonstrated. For many years lens induction was thought to occur at the time the optic vesicle and lens placode came in contact. Since then, studies have revealed that lens placodal progenitor cells are specified already at gastrula stages, much earlier than previously believed, and independent of optic vesicle interactions. In this review, I will focus on how individual signalling molecules, in particular BMP, FGF, Wnt and Shh, regulate the initial specification of lens placodal cells and the progressive development of lens cells. I will discuss recent work that has shed light on the combination of signalling molecules and the molecular interactions that affect lens specification and proper lens formation. I will also discuss proposed tissue interactions important for lens development. A greater knowledge of the molecular interactions during lens induction is likely to have practical benefits in understanding the causes and consequences of lens diseases. Moreover, knowledge regarding lens induction is providing fundamental important insights into inductive processes in development in general.
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Affiliation(s)
- Lena Gunhaga
- Umeå Center for Molecular Medicine, Umeå University, Building 6M, 4th floor, 901 87 Umeå, Sweden.
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14
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Schlosser G. Making senses development of vertebrate cranial placodes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 283:129-234. [PMID: 20801420 DOI: 10.1016/s1937-6448(10)83004-7] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Cranial placodes (which include the adenohypophyseal, olfactory, lens, otic, lateral line, profundal/trigeminal, and epibranchial placodes) give rise to many sense organs and ganglia of the vertebrate head. Recent evidence suggests that all cranial placodes may be developmentally related structures, which originate from a common panplacodal primordium at neural plate stages and use similar regulatory mechanisms to control developmental processes shared between different placodes such as neurogenesis and morphogenetic movements. After providing a brief overview of placodal diversity, the present review summarizes current evidence for the existence of a panplacodal primordium and discusses the central role of transcription factors Six1 and Eya1 in the regulation of processes shared between different placodes. Upstream signaling events and transcription factors involved in early embryonic induction and specification of the panplacodal primordium are discussed next. I then review how individual placodes arise from the panplacodal primordium and present a model of multistep placode induction. Finally, I briefly summarize recent advances concerning how placodal neurons and sensory cells are specified, and how morphogenesis of placodes (including delamination and migration of placode-derived cells and invagination) is controlled.
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Affiliation(s)
- Gerhard Schlosser
- Zoology, School of Natural Sciences & Martin Ryan Institute, National University of Ireland, Galway, Ireland
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15
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The role of Xenopus Rx-L in photoreceptor cell determination. Dev Biol 2009; 327:352-65. [DOI: 10.1016/j.ydbio.2008.12.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 12/02/2008] [Accepted: 12/15/2008] [Indexed: 11/22/2022]
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16
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Hasebe T, Kajita M, Shi YB, Ishizuya-Oka A. Thyroid hormone-up-regulated hedgehog interacting protein is involved in larval-to-adult intestinal remodeling by regulating sonic hedgehog signaling pathway in Xenopus laevis. Dev Dyn 2008; 237:3006-15. [PMID: 18816855 DOI: 10.1002/dvdy.21698] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Sonic hedgehog (Shh) was previously shown to be involved in the larval-to-adult remodeling of the Xenopus laevis intestine. While Shh is transcriptionally regulated by thyroid hormone (TH), the posttranscriptional regulation of Shh signaling during intestinal remodeling is largely unknown. In the present study, we focused on a role of the pan-hedgehog inhibitor, hedgehog interacting protein (Hip), in the spatiotemporal regulation of Shh signaling. Using real-time reverse transcriptase-polymerase chain reaction and in situ hybridization, we show that Hip expression is transiently up-regulated during both natural and TH-induced metamorphosis and that Hip mRNA is localized in the connective tissue adjacent to the adult epithelial primordia expressing Shh. Interestingly, the expression of bone morphogenetic protein-4, a Shh target gene, is hardly detectable where Hip is strongly expressed. Finally, we demonstrate that Hip binds to the N-terminal fragment of processed Shh in vivo, suggesting that Hip suppresses Shh signaling through sequestering Shh.
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Affiliation(s)
- Takashi Hasebe
- Department of Biology, Nippon Medical School, Nakahara-ku, Kawasaki, Kanagawa, Japan.
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Guidato S, Itasaki N. Wise retained in the endoplasmic reticulum inhibits Wnt signaling by reducing cell surface LRP6. Dev Biol 2007; 310:250-63. [PMID: 17765217 DOI: 10.1016/j.ydbio.2007.07.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 07/12/2007] [Accepted: 07/23/2007] [Indexed: 01/18/2023]
Abstract
The Wnt signaling pathway is tightly regulated by extracellular and intracellular modulators. Wise was isolated as a secreted protein capable of interacting with the Wnt co-receptor LRP6. Studies in Xenopus embryos revealed that Wise either enhances or inhibits the Wnt pathway depending on the cellular context. Here we show that the cellular localization of Wise has distinct effects on the Wnt pathway readout. While secreted Wise either synergizes or inhibits the Wnt signals depending on the partner ligand, ER-retained Wise consistently blocks the Wnt pathway. ER-retained Wise reduces LRP6 on the cell surface, making cells less susceptible to the Wnt signal. This study provides a cellular mechanism for the action of Wise and introduces the modulation of cellular susceptibility to Wnt signals as a novel mechanism of the regulation of the Wnt pathway.
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Affiliation(s)
- Sonia Guidato
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London, UK
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Waldman EH, Castillo A, Collazo A. Ablation studies on the developing inner ear reveal a propensity for mirror duplications. Dev Dyn 2007; 236:1237-48. [PMID: 17394250 DOI: 10.1002/dvdy.21144] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The inner ear develops from a simple ectodermal thickening known as the otic placode. Classic embryological manipulations rotating the prospective placode tissue found that the anteroposterior axis was determined before the dorsoventral axis. A small percentage of such rotations also resulted in the formation of mirror duplicated ears, or enantiomorphs. We demonstrate a different embryological manipulation in the frog Xenopus: the physical removal or ablation of either the anterior or posterior half of the placode, which results in an even higher percentage of mirror image ears. Removal of the posterior half results in mirror anterior duplications, whereas removal of the anterior half results in mirror posterior duplications. In contrast, complete extirpation results in more variable phenotypes but never mirror duplications. By the time the otocyst separates from the surface ectoderm, complete extirpation results in no regeneration. To test for a dosage response, differing amounts of the placode or otocyst were ablated. Removal of one third of the placode resulted in normal ears, whereas two-thirds ablations resulted in abnormal ears, including mirror duplications. Recent studies in zebrafish have demonstrated a role for the hedgehog (Hh) signaling pathway in anteroposterior patterning of the developing ear. We have used overexpression of Hedgehog interacting protein (Hip) to block Hh signaling and find that this strategy resulted in mirror duplications of anterior structures, consistent with the results in zebrafish.
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Affiliation(s)
- Erik H Waldman
- Leslie and Susan Gonda (Goldschmied) Department of Cell and Molecular Biology, House Ear Institute, Los Angeles, California 90057, USA
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Hollemann T, Tadjuidje E, Koebernick K, Pieler T. Manipulation of hedgehog signaling in Xenopus by means of embryo microinjection and application of chemical inhibitors. Methods Mol Biol 2007; 397:35-45. [PMID: 18025711 DOI: 10.1007/978-1-59745-516-9_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Xenopus embryos provide a powerful model system to investigate the complex molecular mechanisms, which are controlled by or control the activity of the Hedgehog (Hh) signaling pathway. The use of synthetic mRNA or antisense oligonucleotide (morpholino) microinjection into blastomeres of early embryos or by simply treating the embryos with small organic inhibitors, has already led to an idea of the network in which the Hh pathway is embedded. More needs to be done in order to achieve a detailed understanding of how the different players of the Hh signaling pathway are integrated to control different genetic programs, such as axis formation in early embryos or cell differentiation during retinogenesis.
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Donner AL, Lachke SA, Maas RL. Lens induction in vertebrates: Variations on a conserved theme of signaling events. Semin Cell Dev Biol 2006; 17:676-85. [PMID: 17164096 DOI: 10.1016/j.semcdb.2006.10.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This review provides an overview of our current understanding of signaling mechanisms involved in lens induction, which are presented in context of the major stages of lens induction (competence, bias, inhibition and specification). Although the process of lens induction is generally well conserved, we highlight aspects of induction that vary among species. Finally, this review identifies future challenges in forming an integrated network of signaling pathways involved in lens induction.
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Affiliation(s)
- Amy L Donner
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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21
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Schlosser G. Induction and specification of cranial placodes. Dev Biol 2006; 294:303-51. [PMID: 16677629 DOI: 10.1016/j.ydbio.2006.03.009] [Citation(s) in RCA: 282] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 12/22/2005] [Accepted: 12/23/2005] [Indexed: 12/17/2022]
Abstract
Cranial placodes are specialized regions of the ectoderm, which give rise to various sensory ganglia and contribute to the pituitary gland and sensory organs of the vertebrate head. They include the adenohypophyseal, olfactory, lens, trigeminal, and profundal placodes, a series of epibranchial placodes, an otic placode, and a series of lateral line placodes. After a long period of neglect, recent years have seen a resurgence of interest in placode induction and specification. There is increasing evidence that all placodes despite their different developmental fates originate from a common panplacodal primordium around the neural plate. This common primordium is defined by the expression of transcription factors of the Six1/2, Six4/5, and Eya families, which later continue to be expressed in all placodes and appear to promote generic placodal properties such as proliferation, the capacity for morphogenetic movements, and neuronal differentiation. A large number of other transcription factors are expressed in subdomains of the panplacodal primordium and appear to contribute to the specification of particular subsets of placodes. This review first provides a brief overview of different cranial placodes and then synthesizes evidence for the common origin of all placodes from a panplacodal primordium. The role of various transcription factors for the development of the different placodes is addressed next, and it is discussed how individual placodes may be specified and compartmentalized within the panplacodal primordium. Finally, tissues and signals involved in placode induction are summarized with a special focus on induction of the panplacodal primordium itself (generic placode induction) and its relation to neural induction and neural crest induction. Integrating current data, new models of generic placode induction and of combinatorial placode specification are presented.
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Affiliation(s)
- Gerhard Schlosser
- Brain Research Institute, AG Roth, University of Bremen, FB2, 28334 Bremen, Germany.
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Loulier K, Ruat M, Traiffort E. Analysis of hedgehog interacting protein in the brain and its expression in nitric oxide synthase-positive cells. Neuroreport 2005; 16:1959-62. [PMID: 16272887 DOI: 10.1097/01.wnr.0000187632.91375.81] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hedgehog interacting protein (Hip) and Patched 1 (Ptc1) regulate the cell responses to the morphogen Sonic Hedgehog (Shh). Here, we compare the relative expression patterns of Shh, Hip and Ptc1 transcripts in the E13.5 mouse brain embryo. We observe that the expression of Hip and Ptc1 often overlaps and is found close to Shh-expressing cells, suggesting that both proteins are required for controlling Shh signals. In the adult striatum in which Ptc1 is not detected, we show that a majority of Hip-expressing cells correspond to neurons expressing the neuronal form of nitric oxide synthase. These data raise the hypothesis for a functional link between nitric oxide and Shh signaling and for a nonredundant role of Hip and Ptc1 in the adult brain.
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Affiliation(s)
- Karine Loulier
- CNRS, Signal Transduction and Developmental Neuropharmacology, Laboratory of Cellular and Molecular Neurobiology, Alfred Fessard Institute of Neurobiology, Gif sur Yvette, France
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