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Carron M, Sachslehner AP, Cicekdal MB, Bruggeman I, Demuynck S, Golabi B, De Baere E, Declercq W, Tschachler E, Vleminckx K, Eckhart L. Evolutionary origin of Hoxc13-dependent skin appendages in amphibians. Nat Commun 2024; 15:2328. [PMID: 38499530 PMCID: PMC10948813 DOI: 10.1038/s41467-024-46373-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Accepted: 02/26/2024] [Indexed: 03/20/2024] Open
Abstract
Cornified skin appendages, such as hair and nails, are major evolutionary innovations of terrestrial vertebrates. Human hair and nails consist largely of special intermediate filament proteins, known as hair keratins, which are expressed under the control of the transcription factor Hoxc13. Here, we show that the cornified claws of Xenopus frogs contain homologs of hair keratins and the genes encoding these keratins are flanked by promoters in which binding sites of Hoxc13 are conserved. Furthermore, these keratins and Hoxc13 are co-expressed in the claw-forming epithelium of frog toe tips. Upon deletion of hoxc13, the expression of hair keratin homologs is abolished and the development of cornified claws is abrogated in X. tropicalis. These results indicate that Hoxc13-dependent expression of hair keratin homologs evolved already in stem tetrapods, presumably as a mechanism for protecting toe tips, and that this ancestral genetic program was coopted to the growth of hair in mammals.
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Affiliation(s)
- Marjolein Carron
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University and Center for Medical Genetics, Ghent University Hospital, 9000, Ghent, Belgium
| | | | - Munevver Burcu Cicekdal
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University and Center for Medical Genetics, Ghent University Hospital, 9000, Ghent, Belgium
| | - Inge Bruggeman
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
- VIB-Ugent Center for Inflammation Research, 9000, Ghent, Belgium
| | - Suzan Demuynck
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
| | - Bahar Golabi
- Department of Dermatology, Medical University of Vienna, 1090, Vienna, Austria
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University and Center for Medical Genetics, Ghent University Hospital, 9000, Ghent, Belgium
| | - Wim Declercq
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium
- VIB-Ugent Center for Inflammation Research, 9000, Ghent, Belgium
| | - Erwin Tschachler
- Department of Dermatology, Medical University of Vienna, 1090, Vienna, Austria
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, 9000, Ghent, Belgium.
| | - Leopold Eckhart
- Department of Dermatology, Medical University of Vienna, 1090, Vienna, Austria.
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2
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Tulkens D, Boelens M, Naert T, Carron M, Demuynck S, Dewaele S, Van Isterdael G, Creytens D, Pieters T, Goossens S, Van Vlierberghe P, Vleminckx K. Mutations in the histone methyltransferase Ezh2 drive context-dependent leukemia in Xenopus tropicalis. Leukemia 2023; 37:2404-2413. [PMID: 37794102 DOI: 10.1038/s41375-023-02052-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/06/2023]
Abstract
CRISPR-mediated simultaneous targeting of candidate tumor suppressor genes in Xenopus tropicalis allows fast functional assessment of co-driver genes for various solid tumors. Genotyping of tumors that emerge in the mosaic mutant animals rapidly exposes the gene mutations under positive selection for tumor establishment. However, applying this simple approach to the blood lineage has not been attempted. Multiple hematologic malignancies have mutations in EZH2, encoding the catalytic subunit of the Polycomb Repressive Complex 2. Interestingly, EZH2 can act as an oncogene or a tumor suppressor, depending on cellular context and disease stage. We show here that mosaic CRISPR/Cas9 mediated ezh2 disruption in the blood lineage resulted in early and penetrant acute myeloid leukemia (AML) induction. While animals were co-targeted with an sgRNA that induces notch1 gain-of-function mutations, sequencing of leukemias revealed positive selection towards biallelic ezh2 mutations regardless of notch1 mutational status. Co-targeting dnm2, recurrently mutated in T/ETP-ALL, induced a switch from myeloid towards acute T-cell leukemia. Both myeloid and T-cell leukemias engrafted in immunocompromised hosts. These data underline the potential of Xenopus tropicalis for modeling human leukemia, where mosaic gene disruption, combined with deep amplicon sequencing of the targeted genomic regions, can rapidly and efficiently expose co-operating driver gene mutations.
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Affiliation(s)
- Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Marthe Boelens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Marjolein Carron
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Suzan Demuynck
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Sylviane Dewaele
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- VIB Center for Inflammation Research, Ghent, Belgium
| | - Gert Van Isterdael
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- VIB Flow Core, VIB Center for Inflammation Research, Ghent, Belgium
| | - David Creytens
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Tim Pieters
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Center for Medical Genetics, Ghent University, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Steven Goossens
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Pieter Van Vlierberghe
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium
- Center for Medical Genetics, Ghent University, Ghent, Belgium
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium.
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
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3
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Haas M, Gómez Vázquez JL, Sun DI, Tran HT, Brislinger M, Tasca A, Shomroni O, Vleminckx K, Walentek P. ΔN-Tp63 Mediates Wnt/β-Catenin-Induced Inhibition of Differentiation in Basal Stem Cells of Mucociliary Epithelia. Cell Rep 2020; 28:3338-3352.e6. [PMID: 31553905 PMCID: PMC6935018 DOI: 10.1016/j.celrep.2019.08.063] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/04/2019] [Accepted: 08/21/2019] [Indexed: 12/15/2022] Open
Abstract
Mucociliary epithelia provide a first line of defense against pathogens. Impaired regeneration and remodeling of mucociliary epithelia are associated with dysregulated Wnt/β-catenin signaling in chronic airway diseases, but underlying mechanisms remain elusive, and studies yield seemingly contradicting results. Employing the Xenopus mucociliary epidermis, the mouse airway, and human airway Basal cells, we characterize the evolutionarily conserved roles of Wnt/β-catenin signaling in vertebrates. In multiciliated cells, Wnt is required for cilia formation during differentiation. In Basal cells, Wnt prevents specification of epithelial cell types by activating ΔN-TP63, a master transcription factor, which is necessary and sufficient to mediate the Wnt-induced inhibition of specification and is required to retain Basal cells during development. Chronic Wnt activation leads to remodeling and Basal cell hyperplasia, which are reversible in vivo and in vitro, suggesting Wnt inhibition as a treatment option in chronic lung diseases. Our work provides important insights into mucociliary signaling, development, and disease. Impaired (re-)generation of lung epithelia is associated with Wnt signaling changes in animals and human lung disease patients. Haas et al. demonstrate that ΔN-TP63 is a Wnt-regulated master transcription factor inhibiting (re-) generation of new epithelial cells from stem cells. These findings are equally important for understanding animal development and disease mechanisms.
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Affiliation(s)
- Maximilian Haas
- Internal Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Systems Biological Analysis, Albert Ludwigs University Freiburg, Freiburg, Germany; Spemann Graduate School of Biology and Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - José Luis Gómez Vázquez
- Internal Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Systems Biological Analysis, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Dingyuan Iris Sun
- Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, Berkeley, CA, USA
| | - Hong Thi Tran
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Magdalena Brislinger
- Internal Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Systems Biological Analysis, Albert Ludwigs University Freiburg, Freiburg, Germany; Spemann Graduate School of Biology and Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany; CIBSS - Centre for Integrative Biological Signalling Studies, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Alexia Tasca
- Internal Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Systems Biological Analysis, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Orr Shomroni
- Transcriptome and Genome Core Unit, University Medical Center Göttingen, Göttingen, Germany
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium; Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Peter Walentek
- Internal Medicine IV, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Center for Systems Biological Analysis, Albert Ludwigs University Freiburg, Freiburg, Germany; Spemann Graduate School of Biology and Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany; Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, Berkeley, CA, USA; CIBSS - Centre for Integrative Biological Signalling Studies, Albert Ludwigs University Freiburg, Freiburg, Germany.
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4
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Naert T, Tulkens D, Edwards NA, Carron M, Shaidani NI, Wlizla M, Boel A, Demuynck S, Horb ME, Coucke P, Willaert A, Zorn AM, Vleminckx K. Maximizing CRISPR/Cas9 phenotype penetrance applying predictive modeling of editing outcomes in Xenopus and zebrafish embryos. Sci Rep 2020; 10:14662. [PMID: 32887910 PMCID: PMC7473854 DOI: 10.1038/s41598-020-71412-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/13/2020] [Indexed: 12/11/2022] Open
Abstract
CRISPR/Cas9 genome editing has revolutionized functional genomics in vertebrates. However, CRISPR/Cas9 edited F0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (DSB) repair. Even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. Recently, studies in cell culture systems have shown that the nature of CRISPR/Cas9-mediated mutations can be dependent on local sequence context and can be predicted by computational methods. Here, we demonstrate that similar approaches can be used to forecast CRISPR/Cas9 gene editing outcomes in Xenopus tropicalis, Xenopus laevis, and zebrafish. We show that a publicly available neural network previously trained in mouse embryonic stem cell cultures (InDelphi-mESC) is able to accurately predict CRISPR/Cas9 gene editing outcomes in early vertebrate embryos. Our observations can have direct implications for experiment design, allowing the selection of guide RNAs with predicted repair outcome signatures enriched towards frameshift mutations, allowing maximization of CRISPR/Cas9 phenotype penetrance in the F0 generation.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 71, 9052, Ghent (Zwijnaarde), Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 71, 9052, Ghent (Zwijnaarde), Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Nicole A Edwards
- Division of Developmental Biology, Perinatal Institute, and Center for Stem Cell and Organoid Medicine (CuSTOM), Cincinnati Children's Hospital, Cincinnati, USA
| | - Marjolein Carron
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 71, 9052, Ghent (Zwijnaarde), Belgium
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Nikko-Ideen Shaidani
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, 02543, USA
| | - Marcin Wlizla
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, 02543, USA
| | - Annekatrien Boel
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Suzan Demuynck
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 71, 9052, Ghent (Zwijnaarde), Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Marko E Horb
- National Xenopus Resource and Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, 02543, USA
| | - Paul Coucke
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Andy Willaert
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Aaron M Zorn
- Division of Developmental Biology, Perinatal Institute, and Center for Stem Cell and Organoid Medicine (CuSTOM), Cincinnati Children's Hospital, Cincinnati, USA
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Technologiepark 71, 9052, Ghent (Zwijnaarde), Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Department of Biomolecular Medicine, Ghent University, Ghent, Belgium.
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5
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Naert T, Dimitrakopoulou D, Tulkens D, Demuynck S, Carron M, Noelanders R, Eeckhout L, Van Isterdael G, Deforce D, Vanhove C, Van Dorpe J, Creytens D, Vleminckx K. RBL1 (p107) functions as tumor suppressor in glioblastoma and small-cell pancreatic neuroendocrine carcinoma in Xenopus tropicalis. Oncogene 2020; 39:2692-2706. [PMID: 32001819 DOI: 10.1038/s41388-020-1173-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 01/13/2020] [Accepted: 01/20/2020] [Indexed: 11/09/2022]
Abstract
Alterations of the retinoblastoma and/or the p53 signaling network are associated with specific cancers such as high-grade astrocytoma/glioblastoma, small-cell lung cancer (SCLC), choroid plexus tumors, and small-cell pancreatic neuroendocrine carcinoma (SC-PaNEC). However, the intricate functional redundancy between RB1 and the related pocket proteins RBL1/p107 and RBL2/p130 in suppressing tumorigenesis remains poorly understood. Here we performed lineage-restricted parallel inactivation of rb1 and rbl1 by multiplex CRISPR/Cas9 genome editing in the true diploid Xenopus tropicalis to gain insight into this in vivo redundancy. We show that while rb1 inactivation is sufficient to induce choroid plexus papilloma, combined rb1 and rbl1 inactivation is required and sufficient to drive SC-PaNEC, retinoblastoma and astrocytoma. Further, using a novel Li-Fraumeni syndrome-mimicking tp53 mutant X. tropicalis line, we demonstrate increased malignancy of rb1/rbl1-mutant glioma towards glioblastoma upon concomitant inactivation of tp53. Interestingly, although clinical SC-PaNEC samples are characterized by abnormal p53 expression or localization, in the current experimental models, the tp53 status had little effect on the establishment and growth of SC-PaNEC, but may rather be essential for maintaining chromosomal stability. SCLC was only rarely observed in our experimental setup, indicating requirement of additional or alternative oncogenic insults. In conclusion, we used CRISPR/Cas9 to delineate the tumor suppressor properties of Rbl1, generating new insights in the functional redundancy within the retinoblastoma protein family in suppressing neuroendocrine pancreatic cancer and glioma/glioblastoma.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Dionysia Dimitrakopoulou
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Suzan Demuynck
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Marjolein Carron
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University, Ghent, Belgium
| | - Rivka Noelanders
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Liza Eeckhout
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | - Dieter Deforce
- Laboratory for Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium
| | - Christian Vanhove
- Cancer Research Institute Ghent, Ghent, Belgium
- Infinity lab, Ghent University Hospital, Ghent, Belgium
| | - Jo Van Dorpe
- Cancer Research Institute Ghent, Ghent, Belgium
- Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - David Creytens
- Cancer Research Institute Ghent, Ghent, Belgium
- Department of Pathology, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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6
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Kariminejad A, Szenker-Ravi E, Lekszas C, Tajsharghi H, Moslemi AR, Naert T, Tran HT, Ahangari F, Rajaei M, Nasseri M, Haaf T, Azad A, Superti-Furga A, Maroofian R, Ghaderi-Sohi S, Najmabadi H, Abbaszadegan MR, Vleminckx K, Nikuei P, Reversade B. Homozygous Null TBX4 Mutations Lead to Posterior Amelia with Pelvic and Pulmonary Hypoplasia. Am J Hum Genet 2019; 105:1294-1301. [PMID: 31761294 DOI: 10.1016/j.ajhg.2019.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
The development of hindlimbs in tetrapod species relies specifically on the transcription factor TBX4. In humans, heterozygous loss-of-function TBX4 mutations cause dominant small patella syndrome (SPS) due to haploinsufficiency. Here, we characterize a striking clinical entity in four fetuses with complete posterior amelia with pelvis and pulmonary hypoplasia (PAPPA). Through exome sequencing, we find that PAPPA syndrome is caused by homozygous TBX4 inactivating mutations during embryogenesis in humans. In two consanguineous couples, we uncover distinct germline TBX4 coding mutations, p.Tyr113∗ and p.Tyr127Asn, that segregated with SPS in heterozygous parents and with posterior amelia with pelvis and pulmonary hypoplasia syndrome (PAPPAS) in one available homozygous fetus. A complete absence of TBX4 transcripts in this proband with biallelic p.Tyr113∗ stop-gain mutations revealed nonsense-mediated decay of the endogenous mRNA. CRISPR/Cas9-mediated TBX4 deletion in Xenopus embryos confirmed its restricted role during leg development. We conclude that SPS and PAPPAS are allelic diseases of TBX4 deficiency and that TBX4 is an essential transcription factor for organogenesis of the lungs, pelvis, and hindlimbs in humans.
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Affiliation(s)
| | - Emmanuelle Szenker-Ravi
- Institute of Medical Biology, Agency for Science, Technology, and Research, 8A Biomedical Grove, Singapore 138648, Republic of Singapore
| | - Caroline Lekszas
- Institute of Human Genetics, Julius-Maximilians-Universität, 97074 Würzburg, Germany
| | - Homa Tajsharghi
- School of Health Sciences, Division Biomedicine, University of Skövde, 54128 Skövde, Sweden
| | - Ali-Reza Moslemi
- Institute of Biomedicine, Sahlgrenska University Hospital, Gothenburg University, 41390 Gothenburg, Sweden
| | - Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Hong Thi Tran
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Fatemeh Ahangari
- Kariminejad-Najmabadi Pathology and Genetics Center, Tehran 14665, Iran
| | - Minoo Rajaei
- Fertility and Infertility Research Center, Hormozgan University of Medical Sciences, Bandar Abbas 7919915519, Iran
| | - Mojila Nasseri
- Pardis Clinical and Genetics Laboratory, Mashhad 9177948974, Iran
| | - Thomas Haaf
- Institute of Human Genetics, Julius-Maximilians-Universität, 97074 Würzburg, Germany
| | - Afrooz Azad
- Fertility and Infertility Research Center, Hormozgan University of Medical Sciences, Bandar Abbas 7919915519, Iran
| | - Andrea Superti-Furga
- Division of Genetic Medicine, Lausanne University Hospital (CHUV), University of Lausanne, 1011 Lausanne, Switzerland
| | - Reza Maroofian
- Molecular and Clinical Sciences Institute, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK
| | | | - Hossein Najmabadi
- Kariminejad-Najmabadi Pathology and Genetics Center, Tehran 14665, Iran; Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran 1985713834, Iran
| | - Mohammad Reza Abbaszadegan
- Pardis Clinical and Genetics Laboratory, Mashhad 9177948974, Iran; Division of Human Genetics, Immunology Research Center, Avicenna Research Institute, Mashhad University of Medical Sciences, Mashhad 15731, Iran
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Pooneh Nikuei
- Fertility and Infertility Research Center, Hormozgan University of Medical Sciences, Bandar Abbas 7919915519, Iran.
| | - Bruno Reversade
- Institute of Medical Biology, Agency for Science, Technology, and Research, 8A Biomedical Grove, Singapore 138648, Republic of Singapore; Institute of Molecular and Cell Biology, Agency for Science, Technology, and Research, 61 Biopolis Drive, Singapore 138673, Republic of Singapore; Department of Medical Genetics, Koç University, School of Medicine, 34010 Topkapı, Istanbul, Turkey.
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7
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Li J, Perfetto M, Materna C, Li R, Thi Tran H, Vleminckx K, Duncan MK, Wei S. A new transgenic reporter line reveals Wnt-dependent Snai2 re-expression and cranial neural crest differentiation in Xenopus. Sci Rep 2019; 9:11191. [PMID: 31371771 PMCID: PMC6672020 DOI: 10.1038/s41598-019-47665-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 07/19/2019] [Indexed: 02/06/2023] Open
Abstract
During vertebrate embryogenesis, the cranial neural crest (CNC) forms at the neural plate border and subsequently migrates and differentiates into many types of cells. The transcription factor Snai2, which is induced by canonical Wnt signaling to be expressed in the early CNC, is pivotal for CNC induction and migration in Xenopus. However, snai2 expression is silenced during CNC migration, and its roles at later developmental stages remain unclear. We generated a transgenic X. tropicalis line that expresses enhanced green fluorescent protein (eGFP) driven by the snai2 promoter/enhancer, and observed eGFP expression not only in the pre-migratory and migrating CNC, but also the differentiating CNC. This transgenic line can be used directly to detect deficiencies in CNC development at various stages, including subtle perturbation of CNC differentiation. In situ hybridization and immunohistochemistry confirm that Snai2 is re-expressed in the differentiating CNC. Using a separate transgenic Wnt reporter line, we show that canonical Wnt signaling is also active in the differentiating CNC. Blocking Wnt signaling shortly after CNC migration causes reduced snai2 expression and impaired differentiation of CNC-derived head cartilage structures. These results suggest that Wnt signaling is required for snai2 re-expression and CNC differentiation.
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Affiliation(s)
- Jiejing Li
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA.,Department of Clinical Laboratory, The Affiliated Hospital of KMUST, Medical School, Kunming University of Science and Technology, Kunming, 650032, China
| | - Mark Perfetto
- Department of Biology, West Virginia University, Morgantown, WV, 26506, USA.,Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Christopher Materna
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Rebecca Li
- Brown University, Providence, RI, 02912, USA
| | - Hong Thi Tran
- Department for Molecular Biomedical Research and Center for Medical Genetics, Ghent University, B-9052, Ghent, Belgium
| | - Kris Vleminckx
- Department for Molecular Biomedical Research and Center for Medical Genetics, Ghent University, B-9052, Ghent, Belgium
| | - Melinda K Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Shuo Wei
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
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8
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Dimitrakopoulou D, Tulkens D, Van Vlierberghe P, Vleminckx K. Corrigendum: Xenopus tropicalis: Joining the Armada in the Fight Against Blood Cancer. Front Physiol 2019; 10:210. [PMID: 30930786 PMCID: PMC6427054 DOI: 10.3389/fphys.2019.00210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Dionysia Dimitrakopoulou
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Pieter Van Vlierberghe
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
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9
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Dimitrakopoulou D, Tulkens D, Van Vlierberghe P, Vleminckx K. Xenopus tropicalis: Joining the Armada in the Fight Against Blood Cancer. Front Physiol 2019; 10:48. [PMID: 30774603 PMCID: PMC6367902 DOI: 10.3389/fphys.2019.00048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 01/17/2019] [Indexed: 12/24/2022] Open
Abstract
Aquatic vertebrate organisms such as zebrafish have been used for over a decade to model different types of human cancer, including hematologic malignancies. However, the introduction of gene editing techniques such as CRISPR/Cas9 and TALEN, have now opened the road for other organisms featuring large externally developing embryos that are easily accessible. Thanks to its unique diploid genome that shows a high degree of synteny to the human, combined with its relatively short live cycle, Xenopus tropicalis has now emerged as an additional powerful aquatic model for studying human disease genes. Genome editing techniques are very simple and extremely efficient, permitting the fast and cheap generation of genetic models for human disease. Mosaic disruption of tumor suppressor genes allows the generation of highly penetrant and low latency cancer models. While models for solid human tumors have been recently generated, genetic models for hematologic malignancies are currently lacking for Xenopus. Here we describe our experimental pipeline, based on mosaic genome editing by CRISPR/Cas9, to generate innovative and high-performing leukemia models in X. tropicalis. These add to the existing models in zebrafish and will extend the experimental platform available in aquatic vertebrate organisms to contribute to the field of hematologic malignancies. This will extend our knowledge in the etiology of this cancer and assist the identification of molecular targets for therapeutic intervention.
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Affiliation(s)
- Dionysia Dimitrakopoulou
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Dieter Tulkens
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium
| | - Pieter Van Vlierberghe
- Cancer Research Institute Ghent (CRIG), Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Cancer Research Institute Ghent (CRIG), Ghent, Belgium.,Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
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10
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Abstract
At this time, no molecular targeted therapies exist for treatment of retinoblastoma. This can be, in part, attributed to the lack of animal models that allow for both rapid identification of novel therapeutic targets and hypothesis driven drug testing. Within this scope, we have recently reported the first genuine genetic nonmammalian retinoblastoma cancer model within the aquatic model organism Xenopus tropicalis (Naert et al., Sci Rep 6: 35263, 2016). Here we describe the methods to generate rb1 mosaic mutant Xenopus tropicalis by employing the CRISPR/Cas9 technology. In depth, we discuss short guide RNA (sgRNA) design parameters, generation, quality control, quantification, and delivery followed by several methods for assessing genome editing efficiencies. As such the reader should be capable, by minor changes to the methods described here, to (co-) target rb1 or any one or multiple gene(s) within the Xenopus tropicalis genome by multiplex CRISPR/Cas9 methodology.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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11
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Naert T, Vleminckx K. CRISPR/Cas9 disease models in zebrafish and Xenopus: The genetic renaissance of fish and frogs. Drug Discov Today Technol 2018; 28:41-52. [PMID: 30205880 DOI: 10.1016/j.ddtec.2018.07.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/29/2018] [Accepted: 07/13/2018] [Indexed: 12/11/2022]
Abstract
The speed by which clinical genomics is currently identifying novel potentially pathogenic variants is outperforming the speed by which these can be functionally (genotype-phenotype) annotated in animal disease models. However, over the past few years the emergence of CRISPR/Cas9 as a straight-forward genome editing technology has revolutionized disease modeling in vertebrate non-mammalian model organisms such as zebrafish, medaka and Xenopus. It is now finally possible, by CRISPR/Cas9, to rapidly establish clinically relevant disease models in these organisms. Interestingly, these can provide both cost-effective genotype-phenotype correlations for gene-(variants) and genomic rearrangements obtained from clinical practice, as well as be exploited to perform translational research to improve prospects of disease afflicted patients. In this review, we show an extensive overview of these new CRISPR/Cas9-mediated disease models and provide future prospects that will allow increasingly accurate modeling of human disease in zebrafish, medaka and Xenopus.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Belgium; Cancer Research Institute Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Belgium; Center for Medical Genetics, Ghent University, Belgium; Cancer Research Institute Ghent, Belgium.
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12
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Dimitrakopoulou D, Tulkens D, Naert T, Vlierberghe PV, Vleminckx K. PO-206 Modelling T cell acute lymphoblastic leukaemia using CRISPR/Cas9 mediated genome editing in Xenopus tropicalis. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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13
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Szenker-Ravi E, Altunoglu U, Leushacke M, Bosso-Lefèvre C, Khatoo M, Thi Tran H, Naert T, Noelanders R, Hajamohideen A, Beneteau C, de Sousa SB, Karaman B, Latypova X, Başaran S, Yücel EB, Tan TT, Vlaminck L, Nayak SS, Shukla A, Girisha KM, Le Caignec C, Soshnikova N, Uyguner ZO, Vleminckx K, Barker N, Kayserili H, Reversade B. RSPO2 inhibition of RNF43 and ZNRF3 governs limb development independently of LGR4/5/6. Nature 2018; 557:564-569. [PMID: 29769720 DOI: 10.1038/s41586-018-0118-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
The four R-spondin secreted ligands (RSPO1-RSPO4) act via their cognate LGR4, LGR5 and LGR6 receptors to amplify WNT signalling1-3. Here we report an allelic series of recessive RSPO2 mutations in humans that cause tetra-amelia syndrome, which is characterized by lung aplasia and a total absence of the four limbs. Functional studies revealed impaired binding to the LGR4/5/6 receptors and the RNF43 and ZNRF3 transmembrane ligases, and reduced WNT potentiation, which correlated with allele severity. Unexpectedly, however, the triple and ubiquitous knockout of Lgr4, Lgr5 and Lgr6 in mice did not recapitulate the known Rspo2 or Rspo3 loss-of-function phenotypes. Moreover, endogenous depletion or addition of exogenous RSPO2 or RSPO3 in triple-knockout Lgr4/5/6 cells could still affect WNT responsiveness. Instead, we found that the concurrent deletion of rnf43 and znrf3 in Xenopus embryos was sufficient to trigger the outgrowth of supernumerary limbs. Our results establish that RSPO2, without the LGR4/5/6 receptors, serves as a direct antagonistic ligand to RNF43 and ZNRF3, which together constitute a master switch that governs limb specification. These findings have direct implications for regenerative medicine and WNT-associated cancers.
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Affiliation(s)
| | - Umut Altunoglu
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Marc Leushacke
- Institute of Medical Biology, A*STAR, Singapore, Singapore
| | - Célia Bosso-Lefèvre
- Institute of Medical Biology, A*STAR, Singapore, Singapore.,Department of Paediatrics, National University of Singapore, Singapore, Singapore
| | - Muznah Khatoo
- Institute of Medical Biology, A*STAR, Singapore, Singapore
| | - Hong Thi Tran
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Rivka Noelanders
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | | | - Sergio B de Sousa
- Medical Genetics Unit, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal.,University Clinic of Genetics, Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Birsen Karaman
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Xenia Latypova
- CHU Nantes, Service de Génétique Médicale, Nantes, France
| | - Seher Başaran
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Esra Börklü Yücel
- Medical Genetics Department, Koç University School of Medicine (KUSOM), Istanbul, Turkey
| | - Thong Teck Tan
- Institute of Medical Biology, A*STAR, Singapore, Singapore
| | - Lena Vlaminck
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Shalini S Nayak
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal University, Manipal, India
| | - Cédric Le Caignec
- CHU Nantes, Service de Génétique Médicale, Nantes, France.,INSERM, UMR1238, Bone Sarcoma and Remodeling of Calcified Tissue, Université Bretagne Loire, Nantes, France
| | | | - Zehra Oya Uyguner
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium. .,Center for Medical Genetics, Ghent University, Ghent, Belgium.
| | - Nick Barker
- Institute of Medical Biology, A*STAR, Singapore, Singapore. .,Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa, Japan. .,Centre for Regenerative Medicine, The University of Edinburgh, Edinburgh, UK.
| | - Hülya Kayserili
- Medical Genetics Department, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey. .,Medical Genetics Department, Koç University School of Medicine (KUSOM), Istanbul, Turkey.
| | - Bruno Reversade
- Institute of Medical Biology, A*STAR, Singapore, Singapore. .,Department of Paediatrics, National University of Singapore, Singapore, Singapore. .,Medical Genetics Department, Koç University School of Medicine (KUSOM), Istanbul, Turkey. .,Institute of Molecular and Cellular Biology, A*STAR, Singapore, Singapore. .,Reproductive Biology Laboratory, Academic Medical Center (AMC), Amsterdam-Zuidoost, The Netherlands.
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14
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Borday C, Parain K, Thi Tran H, Vleminckx K, Perron M, Monsoro-Burq AH. An atlas of Wnt activity during embryogenesis in Xenopus tropicalis. PLoS One 2018; 13:e0193606. [PMID: 29672592 PMCID: PMC5908154 DOI: 10.1371/journal.pone.0193606] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/14/2018] [Indexed: 12/22/2022] Open
Abstract
Wnt proteins form a family of highly conserved secreted molecules that are critical mediators of cell-cell signaling during embryogenesis. Partial data on Wnt activity in different tissues and at different stages have been reported in frog embryos. Our objective here is to provide a coherent and detailed description of Wnt activity throughout embryo development. Using a transgenic Xenopus tropicalis line carrying a Wnt-responsive reporter sequence, we depict the spatial and temporal dynamics of canonical Wnt activity during embryogenesis. We provide a comprehensive series of in situ hybridization in whole-mount embryos and in cross-sections, from gastrula to tadpole stages, with special focus on neural tube, retina and neural crest cell development. This collection of patterns will thus constitute a valuable resource for developmental biologists to picture the dynamics of Wnt activity during development.
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Affiliation(s)
- Caroline Borday
- CNRS UMR 3347, INSERM U1021, Univ. Paris Sud, Université Paris Saclay, Centre Universitaire, Orsay, France
- Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
| | - Karine Parain
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France
| | - Hong Thi Tran
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Muriel Perron
- Paris-Saclay Institute of Neuroscience, CNRS, Univ Paris Sud, Université Paris-Saclay, Orsay, France
- * E-mail: (MP); (AHMB)
| | - Anne H. Monsoro-Burq
- CNRS UMR 3347, INSERM U1021, Univ. Paris Sud, Université Paris Saclay, Centre Universitaire, Orsay, France
- Institut Curie Research Division, PSL Research University, CNRS UMR 3347, INSERM U1021, Orsay, France
- Institut Universitaire de France, Paris, France
- * E-mail: (MP); (AHMB)
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15
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Makhija A, Li J, Perfetto M, Wang J, Shah A, Tran HT, Vleminckx K, Wei S. A new transgenic Xenopus reporter line reveals dynamic expression of snail2 during cranial neural crest development. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.778.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Mark Perfetto
- Biological SciencesUniversity of DelawareNewarkDE
- West Virginia UniversityMorgantownVA
| | - Jian Wang
- Biological SciencesUniversity of DelawareNewarkDE
| | | | - Hong Thi Tran
- Department of Biomedical Molecular BiologyGhent UniversityGhentBelgium
- Department for Molecular Biomedical ResearchFlanders Institute for Biotechnology (VIB)GhentBelgium
| | - Kris Vleminckx
- Department of Biomedical Molecular BiologyGhent UniversityGhentBelgium
- Department for Molecular Biomedical ResearchFlanders Institute for Biotechnology (VIB)GhentBelgium
| | - Shuo Wei
- Biological SciencesUniversity of DelawareNewarkDE
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16
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Abstract
The targeted nuclease revolution (ZFN, TALEN, and CRISPR/Cas9) has led to a myriad of reports describing genotyping methodologies for genome edited founders (F0-crispants) and their offspring (F1). As such, choosing a specific genotyping methodology for your Xenopus CRISPR/Cas9 experiments can be challenging. In this chapter we will discuss, with emphasis on Xenopus tropicalis (X. tropicalis), different methods for assessing genome editing efficiencies within F0 CRISPR/Cas9 founders and for identification of their hetero-, compound hetero-, and homozygous mutant F1 offspring. For F0 crispants, we will provide the protocols and the respective (dis)advantages of genotyping with heteroduplex mobility assay (HMA), subclone Sanger sequencing, and sequence trace decomposition. Furthermore, we provide a previously unpublished pipe-line for rapid genotyping of F1 offspring-high resolution melting analysis (HRMA) and sequence trace decomposition-procured from breeding with F0 crispants. As such, we report here the current state-of-the-art cost- and time-effective approaches to perform genotyping of CRISPR/Cas9 experiments for the Xenopus tropicalis researcher.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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17
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Abstract
Many developmental signals are associated with changes in proliferative response. Also, growing organs and tissues can contain different cellular subpopulations with a defined status in the cell cycle, e.g., quiescent in stem cells, high proliferation in progenitors, cell cycle exit in differentiating cells. This chapter describes a method for isolation of individual cell populations from the Xenopus tadpole brain and determination of their cell cycle status using flow cytometry.
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Affiliation(s)
- Rivka Noelanders
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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18
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Naert T, Vleminckx K. Cancer Models in Xenopus tropicalis by CRISPR/Cas9 Mediated Knockout of Tumor Suppressors. Methods Mol Biol 2018; 1865:147-161. [PMID: 30151765 DOI: 10.1007/978-1-4939-8784-9_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
The recent advent of CRISPR/Cas9 as a straightforward genome editing tool has allowed the establishment of the first bona fide genetic cancer models within the diploid aquatic model organism Xenopus tropicalis (X. tropicalis). Within this chapter, we demonstrate the methods for targeting tumor suppressors with the CRISPR/Cas9 system in the developing X. tropicalis embryo. We further illustrate genotyping and phenotyping of the resulting tumor-bearing F0 mosaic mutant animals (crispants). We focus in detail on the histopathological analysis of cancer neoplasms, the methodology to illustrate high proliferative index by proliferation marker immunofluorescence and how to isolate specific (tumor) cell populations by laser capture microdissection. As such, the described pipeline allows for rapid establishment of novel cancer models by CRISPR/Cas9 targeting of established tumor suppressor genes, or novel candidates obtained from clinical data. In conclusion, we thus provide the methodology for modeling human cancer with the highly efficient CRISPR/Cas9 system in F0 X. tropicalis.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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19
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Abstract
In this chapter, we convey a state-of-the art update to the 2014 Nakayama protocol for CRISPR/Cas9 genome engineering in Xenopus tropicalis (X. tropicalis). We discuss in depth, gRNA design software and rules, gRNA synthesis, and procedures for tissue- and tissue-specific CRISPR/Cas9 genome editing by targeted microinjection in X. tropicalis embryos. We demonstrate the methodology by which any standard equipped Xenopus researcher with microinjection experience can generate F0 CRISPR/Cas9 mediated mosaic mutants (crispants) within one to two work-week(s). The described methodology allows CRISPR/Cas9 efficiencies to be high enough to read out phenotypic consequences, and thus perform gene function analysis, in the F0 crispant. Additionally, we provide the framework for performing multiplex tissue-specific CRISPR/Cas9 experiments generating crispants mosaic mutant in up to four genes simultaneously, which can be of importance for Laevis researchers aiming to target by CRISPR/Cas9 both the S and L homeolog of a gene simultaneously. Finally, we discuss off-target concerns, how to minimize these and ways to rapidly bypass reviewer off-target critique by exploiting the advantages of X. tropicalis.
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Affiliation(s)
- Thomas Naert
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Cancer Research Institute Ghent, Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- Cancer Research Institute Ghent, Ghent, Belgium.
- Center for Medical Genetics, Ghent University, Ghent, Belgium.
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20
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Tran HT, Fransen M, Dimitrakopoulou D, Van Imschoot G, Willemarck N, Vleminckx K. Caspase-9 has a nonapoptotic function in Xenopus embryonic primitive blood formation. J Cell Sci 2017; 130:2371-2381. [PMID: 28576973 DOI: 10.1242/jcs.186411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/30/2017] [Indexed: 12/29/2022] Open
Abstract
Caspases constitute a family of cysteine proteases centrally involved in programmed cell death, which is an integral part of normal embryonic and fetal development. However, it has become clear that specific caspases also have functions independent of cell death. In order to identify novel apoptotic and nonapoptotic developmental caspase functions, we designed and transgenically integrated novel fluorescent caspase reporter constructs in developing Xenopus embryos and tadpoles. This model organism has an external development, allowing direct and continuous monitoring. These studies uncovered a nonapoptotic role for the initiator caspase-9 in primitive blood formation. Functional experiments further corroborated that caspase-9, but possibly not the executioners caspase-3 and caspase-7, are required for primitive erythropoiesis in the early embryo. These data reveal a novel nonapoptotic function for the initiator caspase-9 and, for the first time, implicate nonapoptotic caspase activity in primitive blood formation.
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Affiliation(s)
- Hong Thi Tran
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Mathias Fransen
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | | | - Griet Van Imschoot
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium.,VIB-UGent Center for Inflammation Research, B-9052 Ghent, Belgium
| | - Nicolas Willemarck
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Kris Vleminckx
- Department of Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
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21
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Naert T, Van Nieuwenhuysen T, Vleminckx K. TALENs and CRISPR/Cas9 fuel genetically engineered clinically relevant Xenopus tropicalis tumor models. Genesis 2017; 55. [PMID: 28095622 DOI: 10.1002/dvg.23005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 12/12/2022]
Abstract
The targeted nuclease revolution (TALENs, CRISPR/Cas9) now allows Xenopus researchers to rapidly generate custom on-demand genetic knockout models. These novel methods to perform reverse genetics are unprecedented and are fueling a wide array of human disease models within the aquatic diploid model organism Xenopus tropicalis (X. tropicalis). This emerging technology review focuses on the tools to rapidly generate genetically engineered X. tropicalis models (GEXM), with a focus on establishment of genuine genetic and clinically relevant cancer models. We believe that due to particular advantageous characteristics, outlined within this review, GEXM will become a valuable alternative animal model for modeling human cancer. Furthermore, we provide perspectives of how GEXM will be used as a platform for elucidation of novel therapeutic targets and for preclinical drug validation. Finally, we also discuss some future prospects on how the recent expansions and adaptations of the CRISPR/Cas9 toolbox might influence and push forward X. tropicalis cancer research.
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Affiliation(s)
- Thomas Naert
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium
| | - Tom Van Nieuwenhuysen
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium
| | - Kris Vleminckx
- Developmental Biology Unit, Department of Biomedical Molecular Biology, Ghent University, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Belgium
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22
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Abstract
Wnt/β-catenin signaling plays a crucial role throughout all stages of brain development and remains important in the adult brain. Accordingly, many neurological disorders have been linked to Wnt signaling. Defects in Wnt signaling during neural development can give rise to birth defects or lead to neurological dysfunction later in life. Developmental signaling events can also be hijacked in the adult and result in disease. Moreover, knowledge about the physiological role of Wnt signaling in the brain might lead to new therapeutic strategies for neurological diseases. Especially, the important role for Wnt signaling in neural differentiation of pluripotent stem cells has received much attention as this might provide a cure for neurodegenerative disorders. In this review, we summarize the versatile role of Wnt/β-catenin signaling during neural development and discuss some recent studies linking Wnt signaling to neurological disorders.
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Affiliation(s)
- Rivka Noelanders
- Unit of Developmental Biology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Kris Vleminckx
- Unit of Developmental Biology, Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
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23
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Van Nieuwenhuysen T, Naert T, Creytens D, Van Roy F, Vleminckx K. Abstract 5140: TALEN mediated mutation of apc and β-catenin in Xenopus tropicalis as powerful models for Wnt driven cancer and Familial Adenomatous Polyposis (FAP). Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-5140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Hyperactivation of the Wnt pathway is a common hallmark of many cancers. Deregulation of the pathway is mostly due to mutations in the tumor suppressor gene Adenomatous Polyposis Coli (APC) or the transcriptional regulator of the Wnt pathway β-catenin (CTNNB1). Heterozygous germline mutations in the Mutation Cluster Region (MCR) of the APC gene cause Familial Adenomatous Polyposis (FAP), a condition characterized by multiple colorectal polyps, which over time become malignant. FAP patients also frequently suffer from extracolonic manifestations, such as Congenital Hypertrophy of the Retinal Pigment Epithelium (CHRPE), desmoid tumors and medulloblastoma.
Despite many mouse models and the clear etiology of colorectal cancer and FAP, no drugs targeting the Wnt pathway have reached the clinic and there is a need for new genetic animal models. The recent TALEN (Transcription Activator Like Effector Nuclease) and CRISPR/Cas9 gene targeting technologies open the door for novel genetic cancer models. Xenopus tropicalis, an aquatic tetrapod with a true diploid genome, offers unique experimental opportunities to model human cancer.
We have adopted the TALEN technology in Xenopus tropicalis to generate a model for Wnt deregulated cancer, by targeting either APC or β-catenin. Targeting of the apc gene in the MCR region induces phenotypes reminiscent of FAP in tadpoles and froglets, including hyperplasia of the intestinal epithelium, desmoid tumors, retinal hyperproliferation and medulloblastoma. These neoplasms show bi-allelic truncating mutations in the apc gene, associated with activation of the Wnt signalling pathway and increased cell proliferation. Secondly, we generated a more direct model for the hyperactivation of the Wnt pathway by developing TALENs against the Ser33 phosphorylation site of β-catenin. Small in frame deletions removing this phosphorylation site will result in a stabilized dominant active form of β-catenin, activating Wnt signalling at the transcriptional endpoint. Injection of this TALEN pair induces similar neoplasms as apc TALEN injection, including desmoid and brain tumors, indicating that these tumors are the consequence of activated Wnt signalling, rather than any of the other disrupted functions of APC. In addition we were able to achieve very efficient double bi-allelic mutation of apc and other genes in different tumors by co-injection of two TALEN pairs. This creates the opportunity to use our model for therapeutic target validation, simply by co-injection of TALENs (or CRISPR/Cas9) against potential targets together with the apc TALENs.
We have developed the first genetic cancer models in Xenopus tropicalis by using apc or β-catenin TALENs. These models closely resemble human FAP and will be used for preclinical drug screening and to evaluate potential novel therapeutic targets by multiplexed gene targeting via TALEN and CRISPR/Cas9 technology.
Citation Format: Tom Van Nieuwenhuysen, Thomas Naert, David Creytens, Frans Van Roy, Kris Vleminckx. TALEN mediated mutation of apc and β-catenin in Xenopus tropicalis as powerful models for Wnt driven cancer and Familial Adenomatous Polyposis (FAP). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5140. doi:10.1158/1538-7445.AM2015-5140
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Song J, Feng Y, Acke FR, Coucke P, Vleminckx K, Dhooge IJ. Hearing loss in Waardenburg syndrome: a systematic review. Clin Genet 2015; 89:416-425. [PMID: 26100139 DOI: 10.1111/cge.12631] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 06/18/2015] [Accepted: 06/18/2015] [Indexed: 01/14/2023]
Abstract
Waardenburg syndrome (WS) is a rare genetic disorder characterized by hearing loss (HL) and pigment disturbances of hair, skin and iris. Classifications exist based on phenotype and genotype. The auditory phenotype is inconsistently reported among the different Waardenburg types and causal genes, urging the need for an up-to-date literature overview on this particular topic. We performed a systematic review in search for articles describing auditory features in WS patients along with the associated genotype. Prevalences of HL were calculated and correlated with the different types and genes of WS. Seventy-three articles were included, describing 417 individual patients. HL was found in 71.0% and was predominantly bilateral and sensorineural. Prevalence of HL among the different clinical types significantly differed (WS1: 52.3%, WS2: 91.6%, WS3: 57.1%, WS4: 83.5%). Mutations in SOX10 (96.5%), MITF (89.6%) and SNAI2 (100%) are more frequently associated with hearing impairment than other mutations. Of interest, the distinct disease-causing genes are able to better predict the auditory phenotype compared with different clinical types of WS. Consequently, it is important to confirm the clinical diagnosis of WS with molecular analysis in order to optimally inform patients about the risk of HL.
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Affiliation(s)
- J Song
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Y Feng
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - F R Acke
- Department of Otorhinolaryngology, Ghent University/Ghent University Hospital, Ghent, Belgium
| | - P Coucke
- Department of Medical Genetics, Ghent University/Ghent University Hospital, Ghent, Belgium
| | - K Vleminckx
- Department of Medical Genetics, Ghent University/Ghent University Hospital, Ghent, Belgium.,Department for Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - I J Dhooge
- Department of Otorhinolaryngology, Ghent University/Ghent University Hospital, Ghent, Belgium
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Zhang S, Li J, Lea R, Vleminckx K, Amaya E. Fezf2 promotes neuronal differentiation through localised activation of Wnt/β-catenin signalling during forebrain development. Development 2015; 141:4794-805. [PMID: 25468942 PMCID: PMC4299278 DOI: 10.1242/dev.115691] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Brain regionalisation, neuronal subtype diversification and circuit connectivity are crucial events in the establishment of higher cognitive functions. Here we report the requirement for the transcriptional repressor Fezf2 for proper differentiation of neural progenitor cells during the development of the Xenopus forebrain. Depletion of Fezf2 induces apoptosis in postmitotic neural progenitors, with concomitant reduction in forebrain size and neuronal differentiation. Mechanistically, we found that Fezf2 stimulates neuronal differentiation by promoting Wnt/β-catenin signalling in the developing forebrain. In addition, we show that Fezf2 promotes activation of Wnt/β-catenin signalling by repressing the expression of two negative regulators of Wnt signalling, namely lhx2 and lhx9. Our findings suggest that Fezf2 plays an essential role in controlling when and where neuronal differentiation occurs within the developing forebrain and that it does so by promoting local Wnt/β-catenin signalling via a double-repressor model.
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Affiliation(s)
- Siwei Zhang
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Jingjing Li
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Robert Lea
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Kris Vleminckx
- Department for Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Enrique Amaya
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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Rankin SA, Thi Tran H, Wlizla M, Mancini P, Shifley ET, Bloor SD, Han L, Vleminckx K, Wert SE, Zorn AM. A Molecular atlas of Xenopus respiratory system development. Dev Dyn 2014; 244:69-85. [PMID: 25156440 DOI: 10.1002/dvdy.24180] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Respiratory system development is regulated by a complex series of endoderm-mesoderm interactions that are not fully understood. Recently Xenopus has emerged as an alternative model to investigate early respiratory system development, but the extent to which the morphogenesis and molecular pathways involved are conserved between Xenopus and mammals has not been systematically documented. RESULTS In this study, we provide a histological and molecular atlas of Xenopus respiratory system development, focusing on Nkx2.1+ respiratory cell fate specification in the developing foregut. We document the expression patterns of Wnt/β-catenin, fibroblast growth factor (FGF), and bone morphogenetic protein (BMP) signaling components in the foregut and show that the molecular mechanisms of respiratory lineage induction are remarkably conserved between Xenopus and mice. Finally, using several functional experiments we refine the epistatic relationships among FGF, Wnt, and BMP signaling in early Xenopus respiratory system development. CONCLUSIONS We demonstrate that Xenopus trachea and lung development, before metamorphosis, is comparable at the cellular and molecular levels to embryonic stages of mouse respiratory system development between embryonic days 8.5 and 10.5. This molecular atlas provides a fundamental starting point for further studies using Xenopus as a model to define the conserved genetic programs controlling early respiratory system development.
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Affiliation(s)
- Scott A Rankin
- Division of Developmental Biology, Perinatal Institute, Cincinnati Children's Hospital, and the Department of Pediatrics, College of Medicine University of Cincinnati, Cincinnati, Ohio
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El Yakoubi W, Borday C, Hamdache J, Parain K, Tran HT, Vleminckx K, Perron M, Locker M. Hes4 controls proliferative properties of neural stem cells during retinal ontogenesis. Stem Cells 2013; 30:2784-95. [PMID: 22969013 PMCID: PMC3549485 DOI: 10.1002/stem.1231] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 08/08/2012] [Indexed: 11/22/2022]
Abstract
The retina of fish and amphibian contains genuine neural stem cells located at the most peripheral edge of the ciliary marginal zone (CMZ). However, their cell-of-origin as well as the mechanisms that sustain their maintenance during development are presently unknown. We identified Hes4 (previously named XHairy2), a gene encoding a bHLH-O transcriptional repressor, as a stem cell-specific marker of the Xenopus CMZ that is positively regulated by the canonical Wnt pathway and negatively by Hedgehog signaling. We found that during retinogenesis, Hes4 labels a small territory, located first at the pigmented epithelium (RPE)/neural retina (NR) border and later in the retinal margin, that likely gives rise to adult retinal stem cells. We next addressed whether Hes4 might impart this cell subpopulation with retinal stem cell features: inhibited RPE or NR differentiation programs, continuous proliferation, and slow cell cycle speed. We could indeed show that Hes4 overexpression cell autonomously prevents retinal precursor cells from commitment toward retinal fates and maintains them in a proliferative state. Besides, our data highlight for the first time that Hes4 may also constitute a crucial regulator of cell cycle kinetics. Hes4 gain of function indeed significantly slows down cell division, mainly through the lengthening of G1 phase. As a whole, we propose that Hes4 maintains particular stemness features in a cellular cohort dedicated to constitute the adult retinal stem cell pool, by keeping it in an undifferentiated and slowly proliferative state along embryonic retinogenesis. Stem Cells 2012;30:2784–2795
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Tran HT, Vleminckx K. Design and use of transgenic reporter strains for detecting activity of signaling pathways in Xenopus. Methods 2013; 66:422-32. [PMID: 23816788 DOI: 10.1016/j.ymeth.2013.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 06/02/2013] [Accepted: 06/21/2013] [Indexed: 12/19/2022] Open
Abstract
Embryos and larvae of vertebrate species with external development are ideal subjects for investigating the dynamic spatiotemporal activity of developmental signaling pathways. The availability of efficient transgene technologies in Xenopus and zebrafish and the translucency and/or transparency of their embryos and larvae make these two species attractive for direct in vivo imaging of reporter gene expression. In this article we describe the design of efficient signaling reporters, using the Wnt/β-catenin pathway as a representative example. We define methods for validating the reporter constructs and describe how they can be used to generate stable transgenic lines in Xenopus. We provide efficient methods used in our laboratory for raising the tadpoles and froglets rapidly to sexual maturity. We further discuss how the reporter lines can be used for delineating the dynamic activity of a signaling pathway and how modulators of the pathway can be scrutinized via chemical intervention and the micro-injection of synthetic RNAs or morpholinos. The strategic outline discussed in this paper provides a template for studying other developmental signaling pathways in Xenopus.
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Affiliation(s)
- Hong Thi Tran
- Department of Molecular Biomedical Research, VIB, Technologiepark 927, B-9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium
| | - Kris Vleminckx
- Department of Molecular Biomedical Research, VIB, Technologiepark 927, B-9052 Ghent, Belgium; Department of Biomedical Molecular Biology, Ghent University, Technologiepark 927, B-9052 Ghent, Belgium.
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Janssens S, Van Den Broek O, Davenport IR, Akkers RC, Liu F, Veenstra GJC, Hoppler S, Vleminckx K, Destrée O. The Wnt signaling mediator tcf1 is required for expression of foxd3 during Xenopus gastrulation. Int J Dev Biol 2013; 57:49-54. [PMID: 23585352 DOI: 10.1387/ijdb.120191kv] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
TCF1 belongs to the family of LEF1/TCF transcription factors that regulate gene expression downstream of Wnt/β-catenin signaling, which is crucial for embryonic development and is involved in adult stem cell regulation and tumor growth. In early Xenopus embryos, tcf1 plays an important role in mesoderm induction and patterning. Foxd3 emerged as a potential tcf1 target gene in a microarray analysis of gastrula stage embryos. Because foxd3 and tcf1 are coexpressed during gastrulation, we investigated whether foxd3 is regulated by tcf1. By using morpholino-mediated knockdown, we show that during gastrulation foxd3 expression is dependent on tcf1. By chromatin immunoprecipitation, we also demonstrate direct interaction of β-catenin/tcf complexes with the foxd3 gene locus. Hence, our results indicate that tcf1 acts as an essential activator of foxd3, which is critical for dorsal mesoderm formation in early embryos.
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Affiliation(s)
- Sylvie Janssens
- Department of Biomedical Molecular Biology, Ghent University, Belgium
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Borday C, Cabochette P, Parain K, Mazurier N, Janssens S, Tran HT, Sekkali B, Bronchain O, Vleminckx K, Locker M, Perron M. Antagonistic cross-regulation between Wnt and Hedgehog signalling pathways controls post-embryonic retinal proliferation. Development 2012; 139:3499-509. [PMID: 22899850 DOI: 10.1242/dev.079582] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Continuous neurogenesis in the adult nervous system requires a delicate balance between proliferation and differentiation. Although Wnt/β-catenin and Hedgehog signalling pathways are thought to share a mitogenic function in adult neural stem/progenitor cells, it remains unclear how they interact in this process. Adult amphibians produce retinal neurons from a pool of neural stem cells localised in the ciliary marginal zone (CMZ). Surprisingly, we found that perturbations of the Wnt and Hedgehog pathways result in opposite proliferative outcomes of neural stem/progenitor cells in the CMZ. Additionally, our study revealed that Wnt and Hedgehog morphogens are produced in mutually exclusive territories of the post-embryonic retina. Using genetic and pharmacological tools, we found that the Wnt and Hedgehog pathways exhibit reciprocal inhibition. Our data suggest that Sfrp-1 and Gli3 contribute to this negative cross-regulation. Altogether, our results reveal an unexpected antagonistic interplay of Wnt and Hedgehog signals that may tightly regulate the extent of neural stem/progenitor cell proliferation in the Xenopus retina.
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Munoz WA, Kloc M, Cho K, Lee M, Hofmann I, Sater A, Vleminckx K, McCrea PD. Plakophilin-3 is required for late embryonic amphibian development, exhibiting roles in ectodermal and neural tissues. PLoS One 2012; 7:e34342. [PMID: 22496792 PMCID: PMC3320641 DOI: 10.1371/journal.pone.0034342] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/27/2012] [Indexed: 12/31/2022] Open
Abstract
The p120-catenin family has undergone a significant expansion during the evolution of vertebrates, resulting in varied functions that have yet to be discerned or fully characterized. Likewise, members of the plakophilins, a related catenin subfamily, are found throughout the cell with little known about their functions outside the desmosomal plaque. While the plakophilin-3 (Pkp3) knockout mouse resulted in skin defects, we find larger, including lethal effects following its depletion in Xenopus. Pkp3, unlike some other characterized catenins in amphibians, does not have significant maternal deposits of mRNA. However, during embryogenesis, two Pkp3 protein products whose temporal expression is partially complimentary become expressed. Only the smaller of these products is found in adult Xenopus tissues, with an expression pattern exhibiting distinctions as well as overlaps with those observed in mammalian studies. We determined that Xenopus Pkp3 depletion causes a skin fragility phenotype in keeping with the mouse knockout, but more novel, Xenopus tailbud embryos are hyposensitive to touch even in embryos lacking outward discernable phenotypes, and we additionally resolved disruptions in certain peripheral neural structures, altered establishment and migration of neural crest, and defects in ectodermal multiciliated cells. The use of two distinct morpholinos, as well as rescue approaches, indicated the specificity of these effects. Our results point to the requirement of Pkp3 in amphibian embryogenesis, with functional roles in a number of tissue types.
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Affiliation(s)
- William A. Munoz
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- Program in Genes and Development, University of Texas Graduate School of Biomedical Science, Houston, Texas, United States of America
| | - Malgorzata Kloc
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- Department of Surgery, The Methodist Hospital Research Institute, Houston, Texas, United States of America
| | - Kyucheol Cho
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- Program in Genes and Development, University of Texas Graduate School of Biomedical Science, Houston, Texas, United States of America
| | - Moonsup Lee
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- Program in Genes and Development, University of Texas Graduate School of Biomedical Science, Houston, Texas, United States of America
| | - Ilse Hofmann
- Joint Research Division Vascular Biology of the Medical Faculty Mannheim, University of Heidelberg- DKFZ, Mannheim, Germany
| | - Amy Sater
- Biology and Biochemistry Department, University of Houston, Houston, Texas, United States of America
| | - Kris Vleminckx
- Department for Molecular Biomedical Research, Flanders Institute for Biotechnology VIB, Ghent, Belgium
| | - Pierre D. McCrea
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas, United States of America
- Program in Genes and Development, University of Texas Graduate School of Biomedical Science, Houston, Texas, United States of America
- * E-mail:
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Tran HT, Delvaeye M, Verschuere V, Descamps E, Crabbe E, Van Hoorebeke L, McCrea P, Adriaens D, Van Roy F, Vleminckx K. ARVCF depletion cooperates with Tbx1 deficiency in the development of 22q11.2DS-like phenotypes in Xenopus. Dev Dyn 2011; 240:2680-7. [PMID: 22028109 DOI: 10.1002/dvdy.22765] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2011] [Indexed: 12/19/2022] Open
Abstract
The 22q11.2 deletion syndrome is a common dominant genetic disorder characterized by a heterozygous deletion of a cluster of genes on chromosome 22q11.2. TBX1, a transcription factor belonging to the T-box gene family, is a key player in the syndrome. However, heterozygosity of Tbx1 in mouse models does not fully recapitulate the phenotypes characteristic of the disease, which may point to the involvement of other genes in the deleted chromosomal region. Hence, we investigated the contribution of the catenin ARVCF, another gene that is deleted in 22q11.2DS. During Xenopus development, ARVCF mRNA is expressed in the pharyngeal arches and depleting either ARVCF or Tbx1 results in delayed migration of the cranial neural crest cells and in defects in the craniofacial skeleton and aortic arches. Moreover, double depletion of ARVCF and Tbx1 revealed that they act cooperatively, indicating that decreased ARVCF levels may also contribute to 22q11.2DS-associated phenotypes.
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Affiliation(s)
- Hong Thi Tran
- Department for Molecular Biomedical Research, VIB & Ghent University, Ghent, Belgium
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Pourebrahim R, Houtmeyers R, Ghogomu S, Janssens S, Thelie A, Tran HT, Langenberg T, Vleminckx K, Bellefroid E, Cassiman JJ, Tejpar S. Transcription factor Zic2 inhibits Wnt/β-catenin protein signaling. J Biol Chem 2011; 286:37732-40. [PMID: 21908606 DOI: 10.1074/jbc.m111.242826] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Zic transcription factors play critical roles during embryonic development. Mutations in the ZIC2 gene are associated with human holoprosencephaly, but the etiology is still unclear. Here, we report a novel function for ZIC2 as a regulator of β-catenin·TCF4-mediated transcription. We show that ZIC2 can bind directly to the DNA-binding high mobility group box of TCF4 via its zinc finger domain and inhibit the transcriptional activity of the β-catenin·TCF4 complex. However, the binding of TCF4 to DNA was not affected by ZIC2. Zic2 RNA injection completely inhibited β-catenin-induced axis duplication in Xenopus embryos and strongly blocked the ability of β-catenin to induce expression of known Wnt targets in animal caps. Moreover, Zic2 knockdown in transgenic Xenopus Wnt reporter embryos led to ectopic Wnt signaling activity mainly at the midbrain-hindbrain boundary. Together, our results demonstrate a previously unknown role for ZIC2 as a transcriptional regulator of the β-catenin·TCF4 complex.
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Affiliation(s)
- Rasoul Pourebrahim
- Department of Human Genetics, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
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Munoz W, Cho K, Lee M, Ji H, Vleminckx K, Kloc M, McCrea P. Role of Plakophilin-3, a desmosomal catenin, in Xenopus laevis development. Dev Biol 2011. [DOI: 10.1016/j.ydbio.2011.05.551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Janssens S, Denayer T, Deroo T, Van Roy F, Vleminckx K. Direct control of Hoxd1 and Irx3 expression by Wnt/beta-catenin signaling during anteroposterior patterning of the neural axis in Xenopus. Int J Dev Biol 2011; 54:1435-42. [PMID: 20979027 DOI: 10.1387/ijdb.092985sj] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
During and after gastrulation, the neural axis in vertebrates is patterned along the antero-posterior axis by the combined activity of signaling factors secreted in the neural ectoderm and the underlying mesoderm. These signals divide the neural axis into four major divisions: the forebrain, midbrain, hindbrain and spinal chord. Among the signals that pattern the neural axis, Wnts play a prominent role and many patterning genes have been found to be direct Wnt/beta-catenin target genes, including several homeobox domain-containing transcription factors. Here we show that HoxD1 and Irx3 are transcriptionally induced by the Wnt pathway during neurulation. Using induction in the presence of the translation blocking drug cycloheximide and chromatin immunoprecipitation assays, we confirm that HoxD1 and Irx3 are both direct Wnt target genes. In addition, we identified Crabp2 (cellular retinoic acid binding protein 2) as an indirect target that potentially links the activities of Wnt and retinoic acid during antero-posterior patterning.
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Affiliation(s)
- Sylvie Janssens
- Department for Molecular Biomedical Research, VIB, B-9052 Ghent, Belgium
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De Schamphelaere KAC, Stubblefield W, Rodriguez P, Vleminckx K, Janssen CR. The chronic toxicity of molybdate to freshwater organisms. I. Generating reliable effects data. Sci Total Environ 2010; 408:5362-5371. [PMID: 20813395 DOI: 10.1016/j.scitotenv.2010.07.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 06/24/2010] [Accepted: 07/17/2010] [Indexed: 05/29/2023]
Abstract
The European Union regulation on Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH) (EC, 2006) requires the characterization of the chronic toxicity of many chemicals in the aquatic environment, including molybdate (MoO(4)(2-)). Our literature review on the ecotoxicity of molybdate revealed that a limited amount of reliable chronic no observed effect concentrations (NOECs) for the derivation of a predicted no-effect concentration (PNEC) existed. This paper presents the results of additional ecotoxicity experiments that were conducted in order to fulfill the requirements for the derivation of a PNEC by means of the scientifically most robust species sensitivity distribution (SSD) approach (also called the statistical extrapolation approach). Ten test species were chronically exposed to molybdate (added as sodium molybdate dihydrate, Na(2)MoO(4)·2H(2)O) according to internationally accepted standard testing guidelines or equivalent. The 10% effective concentrations (EC10, expressed as measured dissolved molybdenum) for the most sensitive endpoint per species were 62.8-105.6 (mg Mo)/L for Daphnia magna (21day-reproduction), 78.2 (mg Mo)/L for Ceriodaphnia dubia (7day-reproduction), 61.2-366.2 (mg Mo)/L for the green alga Pseudokirchneriella subcapitata (72h-growth rate), 193.6 (mg Mo)/L for the rotifer Brachionus calyciflorus (48h-population growth rate), 121.4 (mg Mo)/L for the midge Chironomus riparius (14day-growth), 211.3 (mg Mo)/L for the snail Lymnaea stagnalis (28day-growth rate), 115.9 (mg Mo)/L for the frog Xenopus laevis (4day-larval development), 241.5 (mg Mo)/L for the higher plant Lemna minor (7day-growth rate), 39.3 (mg Mo)/L for the fathead minnow Pimephales promelas (34day-dry weight/biomass), and 43.2 (mg Mo)/L for the rainbow trout Oncorhynchus mykiss (78day-biomass). These effect concentrations are in line with the few reliable data currently available in the open literature. The data presented in this study can serve as a basis for the derivation of a PNEC(aquatic) that can be used for national and international regulatory purposes and for setting water quality criteria. Using all reliable data that are currently available, a HC(5,50%) (median hazardous concentration affecting 5% of the species) of 38.2 (mg Mo)/L was derived with the statistical extrapolation approach.
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Affiliation(s)
- K A C De Schamphelaere
- Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Belgium.
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Willemarck N, Rysman E, Brusselmans K, Van Imschoot G, Vanderhoydonc F, Moerloose K, Lerut E, Verhoeven G, van Roy F, Vleminckx K, Swinnen JV. Aberrant activation of fatty acid synthesis suppresses primary cilium formation and distorts tissue development. Cancer Res 2010; 70:9453-62. [PMID: 20889723 DOI: 10.1158/0008-5472.can-10-2324] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aberrant activation of fatty acid synthesis is a key feature of many advanced human cancers. Unlike in classical lipogenic tissues, this process has been implicated in membrane production required for rapid cell proliferation. Here, to gain further insight into the consequences of tumor-associated fatty acid synthesis, we have mimicked the lipogenic phenotype of cancer cells in Xenopus embryos by microinjection of RNA encoding the lipogenic transcription factor sterol regulatory element binding protein 1c (SREBP1c). Dramatic morphologic changes were observed that could be linked to alterations in Wnt and Hedgehog signaling, and ultimately to a distortion of the primary cilium. This is a sophisticated microtubular sensory organelle that is expressed on the surface of nearly every cell type and that is lost in many cancers. SREBP1c-induced loss of the primary cilium could be confirmed in mammalian Madin-Darby canine kidney (MDCK) cells and was mediated by changes in the supply of fatty acids. Conversely, inhibition of fatty acid synthesis in highly lipogenic human prostate cancer cells restored the formation of the primary cilium. Lipid-induced ciliary loss was associated with mislocalization of apical proteins, distortion of cell polarization, and aberrant epithelial tissue development as revealed in three-dimensional cultures of MDCK cells and in the developing mouse prostate. These data imply that tumor-associated lipogenesis, in addition to rendering cells more autonomous in terms of lipid supply, disturbs cilium formation and contributes to impaired environmental sensing, aberrant signaling, and distortion of polarized tissue architecture, which are all hallmarks of cancer.
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Affiliation(s)
- Nicolas Willemarck
- Laboratory for Experimental Medicine and Endocrinology, Department of Experimental Medicine, Molecular Small Animal Imaging Centre, K.U. Leuven, Leuven, Belgium
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39
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De Rybel B, Audenaert D, Vert G, Rozhon W, Mayerhofer J, Peelman F, Coutuer S, Denayer T, Jansen L, Nguyen L, Vanhoutte I, Beemster GTS, Vleminckx K, Jonak C, Chory J, Inzé D, Russinova E, Beeckman T. Chemical inhibition of a subset of Arabidopsis thaliana GSK3-like kinases activates brassinosteroid signaling. ACTA ACUST UNITED AC 2009; 16:594-604. [PMID: 19549598 PMCID: PMC4854203 DOI: 10.1016/j.chembiol.2009.04.008] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 03/23/2009] [Accepted: 04/20/2009] [Indexed: 11/28/2022]
Abstract
Glycogen synthase kinase 3 (GSK3) is a key regulator in signaling pathways in both animals and plants. Three Arabidopsis thaliana GSK3s are shown to be related to brassinosteroid (BR) signaling. In a phenotype-based compound screen we identified bikinin, a small molecule that activates BR signaling downstream of the BR receptor. Bikinin directly binds the GSK3 BIN2 and acts as an ATP competitor. Furthermore, bikinin inhibits the activity of six other Arabidopsis GSK3s. Genome-wide transcript analyses demonstrate that simultaneous inhibition of seven GSK3s is sufficient to activate BR responses. Our data suggest that GSK3 inhibition is the sole activation mode of BR signaling and argues against GSK3-independent BR responses in Arabidopsis. The opportunity to generate multiple and conditional knockouts in key regulators in the BR signaling pathway by bikinin represents a useful tool to further unravel regulatory mechanisms.
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Affiliation(s)
- Bert De Rybel
- Department of Plant Systems Biology, VIB, Technologiepark 927, B-9052 Gent, Belgium
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40
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Abstract
Activation of the canonical Wnt pathway leads to the transcriptional activation of a particular subset of downstream Wnt target genes. To track this localized cellular output in a living organism, reporter constructs can be designed containing multimerized consensus lymphoid enhancer binding factor (LEF)-1/T cell factor (TCF) transcription factor binding sites, generally referred to as TCF optimal promoter (TOP) sites. In Xenopus, several Wnt-responsive reporter systems have been designed containing a number of these TOP sites that, in combination with a minimal promoter, drive the expression of a reporter gene. Following transgenic integration in Xenopus embryos, a Wnt reporter tool reveals the spatiotemporal delineation of endogenous Wnt pathway activities throughout development. Assumed to be a general readout of the Wnt pathway, such reporters can assist in elucidating unknown functional implications in developing Xenopus embryos.
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Affiliation(s)
- Tinneke Denayer
- Department for Molecular Biomedical Research, VIB and Molecular Biology, Ghent University, Ghent, Belgium
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41
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Lyons JP, Miller RK, Zhou X, Weidinger G, Deroo T, Denayer T, Park JI, Ji H, Hong JY, Li A, Moon RT, Jones EA, Vleminckx K, Vize PD, McCrea PD. Requirement of Wnt/beta-catenin signaling in pronephric kidney development. Mech Dev 2008; 126:142-59. [PMID: 19100832 DOI: 10.1016/j.mod.2008.11.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Accepted: 11/24/2008] [Indexed: 01/02/2023]
Abstract
The pronephric kidney controls water and electrolyte balance during early fish and amphibian embryogenesis. Many Wnt signaling components have been implicated in kidney development. Specifically, in Xenopus pronephric development as well as the murine metanephroi, the secreted glycoprotein Wnt-4 has been shown to be essential for renal tubule formation. Despite the importance of Wnt signals in kidney organogenesis, little is known of the definitive downstream signaling pathway(s) that mediate their effects. Here we report that inhibition of Wnt/beta-catenin signaling within the pronephric field of Xenopus results in significant losses to kidney epithelial tubulogenesis with little or no effect on adjoining axis or somite development. We find that the requirement for Wnt/beta-catenin signaling extends throughout the pronephric primordium and is essential for the development of proximal and distal tubules of the pronephros as well as for the development of the duct and glomus. Although less pronounced than effects upon later pronephric tubule differentiation, inhibition of the Wnt/beta-catenin pathway decreased expression of early pronephric mesenchymal markers indicating it is also needed in early pronephric patterning. We find that upstream inhibition of Wnt/beta-catenin signals in zebrafish likewise reduces pronephric epithelial tubulogenesis. We also find that exogenous activation of Wnt/beta-catenin signaling within the Xenopus pronephric field results in significant tubulogenic losses. Together, we propose Wnt/beta-catenin signaling is required for pronephric tubule, duct and glomus formation in Xenopus laevis, and this requirement is conserved in zebrafish pronephric tubule formation.
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Affiliation(s)
- Jon P Lyons
- Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 1000, Houston, TX 77030, USA
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42
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Denayer T, Locker M, Borday C, Deroo T, Janssens S, Hecht A, van Roy F, Perron M, Vleminckx K. Canonical Wnt signaling controls proliferation of retinal stem/progenitor cells in postembryonic Xenopus eyes. Stem Cells 2008; 26:2063-74. [PMID: 18556512 DOI: 10.1634/stemcells.2007-0900] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Vertebrate retinal stem cells, which reside quiescently within the ciliary margin, may offer a possibility for treatment of degenerative retinopathies. The highly proliferative retinal precursor cells in Xenopus eyes are confined to the most peripheral region, called the ciliary marginal zone (CMZ). Although the canonical Wnt pathway has been implicated in the developing retina of different species, little is known about its involvement in postembryonic retinas. Using a green fluorescent protein-based Wnt-responsive reporter, we show that in transgenic Xenopus tadpoles, the canonical Wnt signaling is activated in the postembryonic CMZ. To further investigate the functional implications of this, we generated transgenic, hormone-inducible canonical Wnt pathway activating and repressing systems, which are directed to specifically intersect at the nuclear endpoint of transcriptional Wnt target gene activation. We found that postembryonic induction of the canonical Wnt pathway in transgenic retinas resulted in increased proliferation in the CMZ compartment. This is most likely due to delayed cell cycle exit, as inferred from a pulse-chase experiment on 5-bromo-2'-deoxyuridine-labeled retinal precursors. Conversely, repression of the canonical Wnt pathway inhibited proliferation of CMZ cells. Neither activation nor repression of the Wnt pathway affected the differentiated cells in the central retina. We conclude that even at postembryonic stages, the canonical Wnt signaling pathway continues to have a major function in promoting proliferation and maintaining retinal stem cells. These findings may contribute to the eventual design of vertebrate, stem cell-based retinal therapies. Disclosure of potential conflicts of interest is found at the end of this article.
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Affiliation(s)
- Tinneke Denayer
- Department of Molecular Biomedical Research, VIB, Ghent, Belgium
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43
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Sekkali B, Tran HT, Crabbe E, De Beule C, Van Roy F, Vleminckx K. Chicken beta-globin insulator overcomes variegation of transgenes in Xenopus embryos. FASEB J 2008; 22:2534-40. [PMID: 18359926 DOI: 10.1096/fj.07-098111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chromatin structure and gene transcription regulation are intimately linked, and mosaic expression of randomly integrated transgenes into the genome is frequently observed. This variegation of transgene expression is likely due to the genomic integration site, which can affect the behavior of the integrated DNA sequence in a positive or a negative way. Insulators are a class of DNA elements that can protect genes from inappropriate signals emanating from their environment by acting as boundaries that prevent the spreading of nearby condensed chromatin that may otherwise silence expression. Here we show that transgenes escape this silencing in Xenopus laevis and Xenopus tropicalis embryos and that a stable, uniform, and heritable expression pattern is obtained when transgenes are flanked with tandem copies of the chicken beta-globin 5'HS4 insulator. Our data also indicate that the insulator confers copy-number-dependent transgene expression and can increase transgene expression from weak regulatory elements. Hence, it will be an invaluable tool for generating stable lines expressing different levels of a particular coding sequence.
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Affiliation(s)
- Belaïd Sekkali
- Department for Molecular Biomedical Research, VIB-Ghent University, Technologiepark 927, B-9052 Ghent, Belgium
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44
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Suykerbuyk P, Vleminckx K, Pasmans F, Stragier P, Ablordey A, Tran HT, Hermans K, Fleetwood M, Meyers WM, Portaels F. Mycobacterium liflandii infection in European colony of Silurana tropicalis. Emerg Infect Dis 2008; 13:743-6. [PMID: 17553255 PMCID: PMC2738465 DOI: 10.3201/eid1305.060625] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Mycobacterium liflandii causes a fatal frog disease in captive anurans. Here we report, to our knowledge, the first epizootic of mycobacteriosis in a European colony of clawed frogs (Silurana tropicalis), previously imported from a United States biologic supply company. Our findings suggest the emerging potential of this infection through international trade.
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Affiliation(s)
| | - Kris Vleminckx
- Flanders Interuniversity Institute for Biotechnology of Ghent University, Zwijnaarde, Belgium
- Ghent University, Merelbeke, Belgium
| | | | | | - Anthony Ablordey
- Institute of Tropical Medicine, Antwerp, Belgium
- Noguchi Memorial Institute for Medical Research, Legon, Ghana
| | - Hong Thi Tran
- Flanders Interuniversity Institute for Biotechnology of Ghent University, Zwijnaarde, Belgium
- Ghent University, Merelbeke, Belgium
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45
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Vlieghe D, Sandelin A, De Bleser PJ, Vleminckx K, Wasserman WW, van Roy F, Lenhard B. A new generation of JASPAR, the open-access repository for transcription factor binding site profiles. Nucleic Acids Res 2006; 34:D95-7. [PMID: 16381983 PMCID: PMC1347477 DOI: 10.1093/nar/gkj115] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
JASPAR is the most complete open-access collection of transcription factor binding site (TFBS) matrices. In this new release, JASPAR grows into a meta-database of collections of TFBS models derived by diverse approaches. We present JASPAR CORE—an expanded version of the original, non-redundant collection of annotated, high-quality matrix-based transcription factor binding profiles, JASPAR FAM—a collection of familial TFBS models and JASPAR phyloFACTS—a set of matrices computationally derived from statistically overrepresented, evolutionarily conserved regulatory region motifs from mammalian genomes. JASPAR phyloFACTS serves as a non-redundant extension to JASPAR CORE, enhancing the overall breadth of JASPAR for promoter sequence analysis. The new release of JASPAR is available at .
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Affiliation(s)
| | - Albin Sandelin
- Genome Exploration Research Group, RIKEN Genomic Sciences Center (GSC), RIKEN Yokohama Institute1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | | | | | - Wyeth W. Wasserman
- Centre for Molecular Medicine and Therapeutics, Department of Medical Genetics, University of British ColumbiaVancouver, BC, Canada
| | | | - Boris Lenhard
- Computational Biology Unit, Bergen Center for Computational Science, University of BergenThormøhlensgate 55, N-5008 Bergen, Norway
- To whom correspondence should be addressed. Tel: +47 55 84362; Fax: +47 555 84295;
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46
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Denayer T, Van Roy F, Vleminckx K. In vivo tracing of canonical Wnt signaling inXenopustadpoles by means of an inducible transgenic reporter tool. FEBS Lett 2005; 580:393-8. [PMID: 16376877 DOI: 10.1016/j.febslet.2005.11.084] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 11/24/2005] [Accepted: 11/30/2005] [Indexed: 10/25/2022]
Abstract
The canonical Wnt pathway is recurrently used during embryogenesis and adult life. To track the cellular output of Wnt signaling in a living organism, we designed a hormone-inducible Wnt responsive system, capable to dynamically and specifically report Wnt pathway activities through eGFP expression. In contrast to previous in vivo reporters, our system essentially avoids interference of consecutive signals by remaining dormant until addition of hormone, which makes it a valuable tool to map canonical Wnt signaling in post-embryonic stages. Transgenic Xenopus laevis embryos were analyzed revealing at tadpole stage in specific tissues and organs cell populations with high Wnt pathway activity.
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Affiliation(s)
- Tinneke Denayer
- Developmental Biology Unit, Department for Molecular Biomedical Research, VIB-Ghent University, Technologiepark 927, B-9052 Ghent, Belgium
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47
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Park JI, Kim SW, Lyons JP, Ji H, Nguyen TT, Cho K, Barton MC, Deroo T, Vleminckx K, Moon RT, McCrea PD. Kaiso/p120-catenin and TCF/beta-catenin complexes coordinately regulate canonical Wnt gene targets. Dev Cell 2005; 8:843-54. [PMID: 15935774 DOI: 10.1016/j.devcel.2005.04.010] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Revised: 03/01/2005] [Accepted: 04/16/2005] [Indexed: 11/18/2022]
Abstract
Beta-catenin-dependent or canonical Wnt signals are fundamental in animal development and tumor progression. Using Xenopus laevis, we report that the BTB/POZ zinc finger family member Kaiso directly represses canonical Wnt gene targets (Siamois, c-Fos, Cyclin-D1, and c-Myc) in conjunction with TCF/LEF (TCF). Analogous to beta-catenin relief of TCF repressive activity, we show that p120-catenin relieves Kaiso-mediated repression of Siamois. Furthermore, Kaiso and TCF coassociate, and combined Kaiso and TCF derepression results in pronounced Siamois expression and increased beta-catenin coprecipitation with the Siamois promoter. The functional interdependency is underlined by Kaiso suppression of beta-catenin-induced axis duplication and by TCF-3 rescue of Kaiso depletion phenotypes. These studies point to convergence of parallel p120-catenin/Kaiso and beta-catenin/TCF signaling pathways to regulate gene expression in vertebrate development and possibly carcinogenesis.
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Affiliation(s)
- Jae-Il Park
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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48
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Ny A, Koch M, Schneider M, Neven E, Tong RT, Maity S, Fischer C, Plaisance S, Lambrechts D, Héligon C, Terclavers S, Ciesiolka M, Kälin R, Man WY, Senn I, Wyns S, Lupu F, Brändli A, Vleminckx K, Collen D, Dewerchin M, Conway EM, Moons L, Jain RK, Carmeliet P. A genetic Xenopus laevis tadpole model to study lymphangiogenesis. Nat Med 2005; 11:998-1004. [PMID: 16116431 DOI: 10.1038/nm1285] [Citation(s) in RCA: 168] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Accepted: 05/24/2005] [Indexed: 01/10/2023]
Abstract
Lymph vessels control fluid homeostasis, immunity and metastasis. Unraveling the molecular basis of lymphangiogenesis has been hampered by the lack of a small animal model that can be genetically manipulated. Here, we show that Xenopus tadpoles develop lymph vessels from lymphangioblasts or, through transdifferentiation, from venous endothelial cells. Lymphangiography showed that these lymph vessels drain lymph, through the lymph heart, to the venous circulation. Morpholino-mediated knockdown of the lymphangiogenic factor Prox1 caused lymph vessel defects and lymphedema by impairing lymphatic commitment. Knockdown of vascular endothelial growth factor C (VEGF-C) also induced lymph vessel defects and lymphedema, but primarily by affecting migration of lymphatic endothelial cells. Knockdown of VEGF-C also resulted in aberrant blood vessel formation in tadpoles. This tadpole model offers opportunities for the discovery of new regulators of lymphangiogenesis.
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Affiliation(s)
- Annelii Ny
- Flanders Interuniversity Institute for Biotechnology, Center for Transgene Technology and Gene Therapy, Campus Gasthuisberg O&N, Herestraat 49, KULeuven, Leuven, B-3000
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49
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Park JI, Kim SW, Lyons JP, Ji H, Nguyen TT, Cho K, Barton MC, Deroo T, Vleminckx K, Moon RT, McCrea PD. Kaiso/p120-Catenin and TCF/β-Catenin Complexes Coordinately Regulate Canonical Wnt Gene Targets. Dev Cell 2005. [DOI: 10.1016/j.devcel.2005.07.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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50
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Deroo T, Denayer T, Van Roy F, Vleminckx K. Global Inhibition of Lef1/Tcf-dependent Wnt Signaling at Its Nuclear End Point Abrogates Development in Transgenic Xenopus Embryos. J Biol Chem 2004; 279:50670-5. [PMID: 15371453 DOI: 10.1074/jbc.m408969200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Analysis of canonical Wnt signaling during vertebrate development by means of knock-out or transgenic approaches is often hampered by functional redundancy as well as pathway bifurcations downstream of the manipulated components. We report the design of an optimized chimera capable of blocking transcriptional activation of Lef1/Tcf-beta-catenin target genes, thus enabling intervention with the canonical Wnt pathway at its nuclear end point. This construct was made hormone-inducible, both functionally and transcriptionally, and was transgenically integrated in Xenopus embryos. Down-regulation of target genes was clearly observed upon treatment of these embryos with dexamethasone. In addition, exposure of variously aged transgenic embryos to dexamethasone caused complex phenotypes with many new but also several recognizable features stemming from inhibition of canonical Wnt signaling. At least in some tissues, a significant reduction in cell proliferation and an increase in programmed cell death appeared to underlie these phenotypes. Our inducible transgenic system can serve a broad range of experimental settings designed to unveil new functional aspects of Lef1/Tcf-beta-catenin signaling during vertebrate embryogenesis.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Antineoplastic Agents, Hormonal/pharmacology
- Apoptosis
- Blotting, Western
- Bromodeoxyuridine/pharmacology
- Cell Nucleus/metabolism
- Cell Proliferation
- DNA-Binding Proteins/antagonists & inhibitors
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Dexamethasone/pharmacology
- Down-Regulation
- Drosophila
- Embryo, Nonmammalian/metabolism
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Genetic Techniques
- Genetic Vectors
- Homeodomain Proteins/genetics
- Humans
- In Situ Nick-End Labeling
- Lymphoid Enhancer-Binding Factor 1
- Mice
- Microscopy, Fluorescence
- Phenotype
- Plasmids/metabolism
- Promoter Regions, Genetic
- Protein Structure, Tertiary
- Proto-Oncogene Proteins/metabolism
- RNA/chemistry
- RNA/metabolism
- Receptors, Glucocorticoid/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic
- Transcriptional Activation
- Transgenes
- Wnt Proteins
- Xenopus laevis
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Affiliation(s)
- Tom Deroo
- Developmental Biology Unit, Ghent University-Flanders Interuniversity Institute for Biotechnology, Belgium
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