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Vanderhaeghen T, Timmermans S, Eggermont M, Watts D, Vandewalle J, Wallaeys C, Nuyttens L, De Temmerman J, Hochepied T, Dewaele S, Berghe JV, Sanders N, Wielockx B, Beyaert R, Libert C. The impact of hepatocyte-specific deletion of hypoxia-inducible factors on the development of polymicrobial sepsis with focus on GR and PPARα function. Front Immunol 2023; 14:1124011. [PMID: 37006237 PMCID: PMC10060827 DOI: 10.3389/fimmu.2023.1124011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/27/2023] [Indexed: 03/18/2023] Open
Abstract
IntroductionPolymicrobial sepsis causes acute anorexia (loss of appetite), leading to lipolysis in white adipose tissue and proteolysis in muscle, and thus release of free fatty acids (FFAs), glycerol and gluconeogenic amino acids. Since hepatic peroxisome proliferator-activated receptor alpha (PPARα) and glucocorticoid receptor (GR) quickly lose function in sepsis, these metabolites accumulate (causing toxicity) and fail to yield energy-rich molecules such as ketone bodies (KBs) and glucose. The mechanism of PPARα and GR dysfunction is not known.Methods & resultsWe investigated the hypothesis that hypoxia and/or activation of hypoxia inducible factors (HIFs) might play a role in these issues with PPARα and GR. After cecal ligation and puncture (CLP) in mice, leading to lethal polymicrobial sepsis, bulk liver RNA sequencing illustrated the induction of the genes encoding HIF1α and HIF2α, and an enrichment of HIF-dependent gene signatures. Therefore, we generated hepatocyte-specific knock-out mice for HIF1α, HIF2α or both, and a new HRE-luciferase reporter mouse line. After CLP, these HRE-luciferase reporter mice show signals in several tissues, including the liver. Hydrodynamic injection of an HRE-luciferase reporter plasmid also led to (liver-specific) signals in hypoxia and CLP. Despite these encouraging data, however, hepatocyte-specific HIF1α and/or HIF2α knock-out mice suggest that survival after CLP was not dependent on the hepatocyte-specific presence of HIF proteins, which was supported by measuring blood levels of glucose, FFAs, and KBs. The HIF proteins were also irrelevant in the CLP-induced glucocorticoid resistance, but we found indications that the absence of HIF1α in hepatocytes causes less inactivation of PPARα transcriptional function.ConclusionWe conclude that HIF1α and HIF2α are activated in hepatocytes in sepsis, but their contribution to the mechanisms leading to lethality are minimal.
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Affiliation(s)
- Tineke Vanderhaeghen
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Steven Timmermans
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Melanie Eggermont
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Deepika Watts
- Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
- Deutsche Forschungsgemeinschaft (DFG) Research Centre and Cluster of Excellence for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Jolien Vandewalle
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Charlotte Wallaeys
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Louise Nuyttens
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Joyca De Temmerman
- Department of Nutrition, Genetics, and Ethology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
- Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Tino Hochepied
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sylviane Dewaele
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Joke Vanden Berghe
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Niek Sanders
- Department of Nutrition, Genetics, and Ethology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
- Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Ben Wielockx
- Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
- Deutsche Forschungsgemeinschaft (DFG) Research Centre and Cluster of Excellence for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Rudi Beyaert
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Flanders Institute for Biotechnology (VIB) Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- *Correspondence: Claude Libert,
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Ma Z, Zhu P, Pang M, Guo L, Chang N, Zheng J, Zhu X, Gao C, Huang H, Cui Z, Xiong JW, Peng J, Chen J. A novel inducible mutagenesis screen enables to isolate and clone both embryonic and adult zebrafish mutants. Sci Rep 2017; 7:10381. [PMID: 28871129 PMCID: PMC5583359 DOI: 10.1038/s41598-017-10968-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/17/2017] [Indexed: 12/14/2022] Open
Abstract
Conventional genetic screens for recessive mutants are inadequate for studying biological processes in the adult vertebrate due to embryonic lethality. Here, we report that a novel inducible mutagenesis system enables to study gene function in both embryonic and adult zebrafish. This system yields genetic mutants with conditional ectopic over- or under-expression of genes in F1 heterozygotes by utilizing inducible Tet-On transcriptional activation of sense or anti-sense transcripts from entrapped genes by Tol2 transposase-meditated transgenesis. Pilot screens identified 37 phenotypic mutants displaying embryonic defects (34 lines), adult fin regeneration defects (7 lines), or defects at both stages (4 lines). Combination of various techniques (such as: generating a new mutant allele, injecting gene specific morpholino or mRNA etc) confirms that Dox-induced embryonic abnormalities in 10 mutants are due to dysfunction of entrapped genes; and that Dox-induced under-expression of 6 genes causes abnormal adult fin regeneration. Together, this work presents a powerful mutagenesis system for genetic analysis from zebrafish embryos to adults in particular and other model organisms in general.
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Affiliation(s)
- Zhipeng Ma
- Key laboratory for Molecular Animal Nutrition, Ministry of Education, Innovation Center for Signaling Network, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Peipei Zhu
- Key laboratory for Molecular Animal Nutrition, Ministry of Education, Innovation Center for Signaling Network, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Meijun Pang
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100871, China
| | - Liwei Guo
- Key laboratory for Molecular Animal Nutrition, Ministry of Education, Innovation Center for Signaling Network, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Nannan Chang
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100871, China
| | - Jiyuan Zheng
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100871, China
| | - Xiaojun Zhu
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100871, China
| | - Ce Gao
- College of Animal Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China
| | - Honghui Huang
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, State Key Laboratory Breeding Base of Eco-Environments and Bio-Resources of the Three Gorges Reservoir Region, School of Life Sciences, Southwest University, 2 Tiansheng Road, Beibei, Chongqing, 400715, China
| | - Zongbin Cui
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, 8 Dong Hu Nan Road, Wuhan, Hubei, 430072, P. R. China
| | - Jing-Wei Xiong
- Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, and State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100871, China.
| | - Jinrong Peng
- College of Animal Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China.
| | - Jun Chen
- Key laboratory for Molecular Animal Nutrition, Ministry of Education, Innovation Center for Signaling Network, College of Life Sciences, Zhejiang University, 866 Yu Hang Tang Road, Hangzhou, 310058, China.
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Takata N, Sakakura E, Kasukawa T, Sakuma T, Yamamoto T, Sasai Y. Establishment of Functional Genomics Pipeline in Mouse Epiblast-Like Tissue by Combining Transcriptomic Analysis and Gene Knockdown/Knockin/Knockout, Using RNA Interference and CRISPR/Cas9. Hum Gene Ther 2016; 27:436-50. [PMID: 26839115 DOI: 10.1089/hum.2015.148] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The epiblast (foremost embryonic ectoderm) generates all three germ layers and therefore has crucial roles in the formation of all mammalian body cells. However, regulation of epiblast gene expression is poorly understood because of the difficulty of manipulating epiblast tissues in vivo. In the present study, using the self-organizing properties of mouse embryonic stem cell (ESC), we generated and characterized epiblast-like tissue in three-dimensional culture. We identified significant genome-wide gene expression changes in this epiblast-like tissue by transcriptomic analysis. In addition, we identified the particular significance of the Erk/Mapk and integrin-linked kinase pathways, and genes related to ectoderm/epithelial formation, using the bioinformatics resources IPA and DAVID. Here, we focused on Fgf5, which ranked in the top 10 among the discovered genes. To develop a functional analysis of Fgf5, we created an efficient method combining CRISPR/Cas9-mediated genome engineering and RNA interference (RNAi). Notably, we show one-step generation of various Fgf5 reporter lines including heterozygous and homozygous knockins (the GET method). For time- and dose-dependent depletion of fgf5 over the course of development, we generated an ESC line harboring Tol2 transposon-mediated integration of an inducible short hairpin RNA interference system (pdiRNAi). Our findings raised the possibility that Fgf/Erk signaling and apicobasal epithelial integrity are important factors in epiblast development. In addition, our methods provide a framework for a broad array of applications in the areas of mammalian genetics and molecular biology to understand development and to improve future therapeutics.
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Affiliation(s)
- Nozomu Takata
- 1 Laboratory for In Vitro Histogenesis, RIKEN Center for Developmental Biology , Hyogo, Japan
| | - Eriko Sakakura
- 1 Laboratory for In Vitro Histogenesis, RIKEN Center for Developmental Biology , Hyogo, Japan
| | - Takeya Kasukawa
- 2 Large Scale Data Managing Unit, RIKEN Center for Life Science Technologies , Kanagawa, Japan
| | - Tetsushi Sakuma
- 3 Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University , Hiroshima, Japan
| | - Takashi Yamamoto
- 3 Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University , Hiroshima, Japan
| | - Yoshiki Sasai
- 4 Laboratory for Organogenesis and Neurogenesis, RIKEN Center for Developmental Biology , Hyogo, Japan
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Using Xenopus Embryos to Study Transcriptional and Posttranscriptional Gene Regulatory Mechanisms of Intermediate Filaments. Methods Enzymol 2016; 568:635-60. [DOI: 10.1016/bs.mie.2015.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Gutierrez-Triana JA, Herget U, Lichtner P, Castillo-Ramírez LA, Ryu S. A vertebrate-conserved cis-regulatory module for targeted expression in the main hypothalamic regulatory region for the stress response. BMC DEVELOPMENTAL BIOLOGY 2014; 14:41. [PMID: 25427861 PMCID: PMC4248439 DOI: 10.1186/s12861-014-0041-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 11/11/2014] [Indexed: 01/30/2023]
Abstract
Background The homeodomain transcription factor orthopedia (Otp) is an evolutionarily conserved regulator of neuronal fates. In vertebrates, Otp is necessary for the proper development of different regions of the brain and is required in the diencephalon to specify several hypothalamic cell types, including the cells that control the stress response. To understand how this widely expressed transcription factor accomplishes hypothalamus-specific functions, we performed a comprehensive screening of otp cis-regulatory regions in zebrafish. Results Here, we report the identification of an evolutionarily conserved vertebrate enhancer module with activity in a restricted area of the forebrain, which includes the region of the hypothalamus that controls the stress response. This region includes neurosecretory cells producing Corticotropin-releasing hormone (Crh), Oxytocin (Oxt) and Arginine vasopressin (Avp), which are key components of the stress axis. Lastly, expression of the bacterial nitroreductase gene under this specific enhancer allowed pharmacological attenuation of the stress response in zebrafish larvae. Conclusion Vertebrates share many cellular and molecular components of the stress response and our work identified a striking conservation at the cis-regulatory level of a key hypothalamic developmental gene. In addition, this enhancer provides a useful tool to manipulate and visualize stress-regulatory hypothalamic cells in vivo with the long-term goal of understanding the ontogeny of the stress axis in vertebrates. Electronic supplementary material The online version of this article (doi:10.1186/s12861-014-0041-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jose Arturo Gutierrez-Triana
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,Current address: Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 230, D-69120, Heidelberg, Germany.
| | - Ulrich Herget
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology, University of Heidelberg, Heidelberg, Germany.
| | - Patrick Lichtner
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany.
| | - Luis A Castillo-Ramírez
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany. .,The Hartmut Hoffmann-Berling International Graduate School of Molecular and Cellular Biology, University of Heidelberg, Heidelberg, Germany.
| | - Soojin Ryu
- Developmental Genetics of the Nervous System, Max Planck Institute for Medical Research, Jahnstrasse 29, D-69120, Heidelberg, Germany.
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Wang C, Szaro BG. A method for using direct injection of plasmid DNA to study cis-regulatory element activity in F0 Xenopus embryos and tadpoles. Dev Biol 2014; 398:11-23. [PMID: 25448690 DOI: 10.1016/j.ydbio.2014.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 10/31/2014] [Accepted: 11/11/2014] [Indexed: 11/17/2022]
Abstract
The ability to express exogenous reporter genes in intact, externally developing embryos, such as Xenopus, is a powerful tool for characterizing the activity of cis-regulatory gene elements during development. Although methods exist for generating transgenic Xenopus lines, more simplified methods for use with F0 animals would significantly speed the characterization of these elements. We discovered that injecting 2-cell stage embryos with a plasmid bearing a ϕC31 integrase-targeted attB element and two dual β-globin HS4 insulators flanking a reporter transgene in opposite orientations relative to each other yielded persistent expression with sufficiently high penetrance for characterizing the activity of the promoter without having to coinject integrase RNA. Expression began appropriately during development and persisted into swimming tadpole stages without perturbing the expression of the cognate endogenous gene. Coinjected plasmids having the same elements but expressing different reporter proteins were reliably coexpressed within the same cells, providing a useful control for variations in injections between animals. To overcome the high propensity of these plasmids to undergo recombination, we developed a method for generating them using conventional cloning methods and DH5α cells for propagation. We conclude that this method offers a convenient and reliable way to evaluate the activity of cis-regulatory gene elements in the intact F0 embryo.
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Affiliation(s)
- Chen Wang
- Department of Biological Sciences and the Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
| | - Ben G Szaro
- Department of Biological Sciences and the Center for Neuroscience Research, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
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7
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Smoczer C, Hooker L, Sachani SS, Crawford MJ. Microinjection manipulations in the elucidation of Xenopus brain development. Methods Mol Biol 2014; 1082:143-54. [PMID: 24048932 DOI: 10.1007/978-1-62703-655-9_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Microinjection has a long and distinguished history in Xenopus and has been used to introduce a surprisingly diverse array of agents into embryos by both intra- and intercellular means. In addition to nuclei, investigators have variously injected peptides, antibodies, biologically active chemicals, lineage markers, mRNA, DNA, morpholinos, and enzymes. While enumerating many of the different microinjection approaches that can be taken, we will focus upon the mechanical operations and options available to introduce mRNA, DNA, and morpholinos intracellularly into early stage embryos for the study of neurogenesis.
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Efficient ROSA26-Based Conditional and/or Inducible Transgenesis Using RMCE-Compatible F1 Hybrid Mouse Embryonic Stem Cells. Stem Cell Rev Rep 2013; 9:774-85. [DOI: 10.1007/s12015-013-9458-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Haenebalcke L, Goossens S, Dierickx P, Bartunkova S, D'Hont J, Haigh K, Hochepied T, Wirth D, Nagy A, Haigh JJ. The ROSA26-iPSC mouse: a conditional, inducible, and exchangeable resource for studying cellular (De)differentiation. Cell Rep 2013; 3:335-41. [PMID: 23395636 DOI: 10.1016/j.celrep.2013.01.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 12/03/2012] [Accepted: 01/14/2013] [Indexed: 11/18/2022] Open
Abstract
Control of cellular (de)differentiation in a temporal, cell-specific, and exchangeable manner is of paramount importance in the field of reprogramming. Here, we have generated and characterized a mouse strain that allows iPSC generation through the Cre/loxP conditional and doxycycline/rtTA-controlled inducible expression of the OSKM reprogramming factors entirely from within the ROSA26 locus. After reprogramming, these factors can be replaced by genes of interest-for example, to enhance lineage-directed differentiation-with the use of a trap-coupled RMCE reaction. We show that, similar to ESCs, Dox-controlled expression of the cardiac transcriptional regulator Mesp1 together with Wnt inhibition enhances the generation of functional cardiomyocytes upon in vitro differentiation of such RMCE-retargeted iPSCs. This ROSA26-iPSC mouse model is therefore an excellent tool for studying both cellular reprogramming and lineage-directed differentiation factors from the same locus and will greatly facilitate the identification and ease of functional characterization of the genetic/epigenetic determinants involved in these complex processes.
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Affiliation(s)
- Lieven Haenebalcke
- Vascular Cell Biology Unit, VIB Department for Molecular Biomedical Research, Ghent University, Technologiepark 927, 9052 Zwijnaarde Ghent, 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] [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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Love NR, Thuret R, Chen Y, Ishibashi S, Sabherwal N, Paredes R, Alves-Silva J, Dorey K, Noble AM, Guille MJ, Sasai Y, Papalopulu N, Amaya E. pTransgenesis: a cross-species, modular transgenesis resource. Development 2012; 138:5451-8. [PMID: 22110059 DOI: 10.1242/dev.066498] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
As studies aim increasingly to understand key, evolutionarily conserved properties of biological systems, the ability to move transgenesis experiments efficiently between organisms becomes essential. DNA constructions used in transgenesis usually contain four elements, including sequences that facilitate transgene genome integration, a selectable marker and promoter elements driving a coding gene. Linking these four elements in a DNA construction, however, can be a rate-limiting step in the design and creation of transgenic organisms. In order to expedite the construction process and to facilitate cross-species collaborations, we have incorporated the four common elements of transgenesis into a modular, recombination-based cloning system called pTransgenesis. Within this framework, we created a library of useful coding sequences, such as various fluorescent protein, Gal4, Cre-recombinase and dominant-negative receptor constructs, which are designed to be coupled to modular, species-compatible selectable markers, promoters and transgenesis facilitation sequences. Using pTransgenesis in Xenopus, we demonstrate Gal4-UAS binary expression, Cre-loxP-mediated fate-mapping and the establishment of novel, tissue-specific transgenic lines. Importantly, we show that the pTransgenesis resource is also compatible with transgenesis in Drosophila, zebrafish and mammalian cell models. Thus, the pTransgenesis resource fosters a cross-model standardization of commonly used transgenesis elements, streamlines DNA construct creation and facilitates collaboration between researchers working on different model organisms.
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Affiliation(s)
- Nick R Love
- Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester, UK
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Abstract
Tissue-specific and inducible control of transgene expression is a cornerstone of modern studies in developmental biology. Even though such control of transgene expression has been accomplished in Xenopus, no general or widely available set of transgenic lines have been produced akin to those found in mouse and zebrafish. Here, I describe the design and characterization of transgenic lines in Xenopus constituting the Tet-On binary transgene expression system comprising two components: (1) rtTA transgenic lines, i.e., lines harboring the doxycycline- (Dox-) dependent transgenic transcription factor rtTA under control of a tissue-specific promoter and (2) transgenic promoter (TRE) transgenic lines, i.e., lines harboring a gene of interest (hereafter called the transgene) under control of a promoter (TRE). In double transgenic animals, i.e., embryos or tadpoles harboring both the rtTA and TRE components, transgene expression remains off the absence of Dox. Addition of Dox to the rearing water causes a conformational change in rtTA allowing it to bind the TRE promoter and induce transgene expression. Tissue specificity of transgene expression is determined by the promoter regulating rtTA expression, and inducibility is determined by the addition of Dox to the rearing water. Deposition of rtTA and TRE transgenic lines enabling tissue-specific inducible control of transgene expression into the Xenopus stock center will provide a powerful and flexible resource for studies in developmental biology.
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Affiliation(s)
- Daniel R Buchholz
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA.
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Prototypic chromatin insulator cHS4 protects retroviral transgene from silencing in Schistosoma mansoni. Transgenic Res 2011; 21:555-66. [PMID: 21918820 DOI: 10.1007/s11248-011-9556-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 08/31/2011] [Indexed: 02/06/2023]
Abstract
Vesicular stomatitis virus glycoprotein (VSVG) pseudotyped murine leukemia virus (MLV) virions can transduce schistosomes, leading to chromosomal integration of reporter transgenes. To develop VSVG-MLV for functional genomics in schistosomes, the influence of the chicken β-globin cHS4 element, a prototypic chromatin insulator, on transgene expression was examined. Plasmid pLNHX encoding the MLV 5'- and 3'-Long Terminal Repeats flanking the neomycin phosphotransferase gene (neo) was modified to include, within the U3 region of the 3'-LTR, active components of cHS4 insulator, the 250 bp core fused to the 400 bp 3'-region. Cultured larvae of Schistosoma mansoni were transduced with virions from producer cells transfected with control or cHS4-bearing plasmids. Schistosomules transduced with cHS4 virions expressed 2-20 times higher levels of neo than controls, while carrying comparable numbers of integrated proviral transgenes. The findings not only demonstrated that cHS4 was active in schistosomes but also they represent the first report of activity of cHS4 in any Lophotrochozoan species, which has significant implications for evolutionary conservation of heterochromatin regulation. The findings advance prospects for transgenesis in functional genomics of the schistosome genome to discover intervention targets because they provide the means to enhance and extend transgene activity including for vector based RNA interference.
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A 3,387 bp 5'-flanking sequence of the goat alpha-S1-casein gene provides correct tissue-specific expression of human granulocyte colony-stimulating factor (hG-CSF) in the mammary gland of transgenic mice. Transgenic Res 2011; 21:485-98. [PMID: 21881921 DOI: 10.1007/s11248-011-9547-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 08/16/2011] [Indexed: 10/17/2022]
Abstract
A new expression vector containing the 1,944 bp 5'-flanking regulatory region together with exon 1 and intron 1 of the goat alpha-S1-casein gene (CSN1S1), the full-sized human granulocyte colony-stimulating factor gene (hGCSF) and the 3'-flanking sequence of the bovine CSN1S1, was created. The vector DNA was used for generation of four mouse transgenic lines. The transgene was integrated into chromosomes 8 and 12 of two founders as 2 and 5 copies, respectively. Tissue-specific secretion of hG-CSF into the milk of transgenic mice was in the range of 19-40 μg/ml. RT-PCR analysis of various tissues of the transgenic mice demonstrated that expression of hGCSF was detected in only the mammary gland in the progeny of all founders. Moreover, cells were shown to be positive for hG-CSF by immunofluorescent analysis in the mammary glands but not in any other tissues. There were no signs of mosaic expression in the mammary gland. Trace amounts of hG-CSF were detected in the serum of females of two transgenic lines during lactation only. However, no transgenic mice showed any changes in hematopoiesis based on the number of granulocytes in blood. Immunoblotting of hG-CSF in the milk of transgenic mice revealed two forms, presumably the glycosylated and non-glycosylated forms. The hematopoietic activity of hG-CSF in the milk of transgenic females is comparable to that of recombinant G-CSF. In general, the data obtained in this study show that the new expression vector is able to provide correct tissue-specific expression of hG-CSF with high biological activity in transgenic mice.
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15
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Rankin SA, Zorn AM, Buchholz DR. New doxycycline-inducible transgenic lines in Xenopus. Dev Dyn 2011; 240:1467-74. [PMID: 21491543 DOI: 10.1002/dvdy.22642] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2011] [Indexed: 01/21/2023] Open
Abstract
We have characterized two new transgenic Xenopus lines enabling transgene expression using the Tet-On inducible system. An inducer line expresses the doxycycline- (Dox-) activated transcription factor rtTA under control of the ubiquitous promoter CMV. A responder line enables Dox-inducible expression of a dominant positive thyroid hormone receptor via a tetracycline responsive transgenic promoter (TRE). Dox-induced expression of transgenic GFP mRNA was detectable after 3 hr and increased up to 10- to 50-fold by 2 days depending on dose of Dox. Induced GFP mRNA expression returned to uninduced levels within 3 days upon Dox removal. Treatment of rtTA inducer and TRE responder double transgenic animals with Dox caused acceleration of metamorphic changes in thyroid hormone-response gene expression and morphology. These transgenic lines will be made available through the new Xenopus Stock Center and will serve as valuable tools for genetic analysis of development and metamorphosis.
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Affiliation(s)
- Scott A Rankin
- Division of Developmental Biology, Cincinnati Children's Research Foundation and Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45208, USA
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16
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Iskovich S, Goldenberg-Cohen N, Stein J, Yaniv I, Farkas DL, Askenasy N. β-Cell Neogenesis: Experimental Considerations in Adult Stem Cell Differentiation. Stem Cells Dev 2011; 20:569-82. [DOI: 10.1089/scd.2010.0342] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Svetlana Iskovich
- Frankel Laboratory, Center for Stem Cell Research, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Nitza Goldenberg-Cohen
- Krieger Laboratory of Ophthalmology, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
| | - Jerry Stein
- Bone Marrow Transplantation Unit, Department of Pediatric Hematology-Oncology, Petach Tikva, Israel
| | - Isaac Yaniv
- Bone Marrow Transplantation Unit, Department of Pediatric Hematology-Oncology, Petach Tikva, Israel
| | | | - Nadir Askenasy
- Frankel Laboratory, Center for Stem Cell Research, Schneider Children's Medical Center of Israel, Petach Tikva, Israel
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Wnt/beta-catenin signaling is involved in the induction and maintenance of primitive hematopoiesis in the vertebrate embryo. Proc Natl Acad Sci U S A 2010; 107:16160-5. [PMID: 20805504 DOI: 10.1073/pnas.1007725107] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The formation of primitive (embryonic) blood in vertebrates is mediated by spatio-temporally restricted signaling between different tissue layers. In Xenopus, in which primitive blood originates in the ventral blood island, this involves the secretion of bone morphogenetic protein (BMP) ligands by the ectoderm that signal to the underlying mesoderm during gastrulation. Using novel transgenic reporter lines, we report that the canonical Wnt/β-catenin pathway is also activated in the blood islands in Xenopus. Furthermore, Wnt-reporter activity was also detected in the blood islands of the mouse yolk sac. By using morpholino-mediated depletion in Xenopus, we identified Wnt4 as the ligand that is expressed in the mesoderm of the ventral blood island and is essential for the expression of hematopoietic and erythroid marker genes. Injection of an inducible Wnt-interfering construct further showed that, during gastrulation, Wnt/β-catenin signaling is required both in the mesoderm and in the overlying ectoderm for the formation of the ventral blood island. Using recombination assays with embryonic explants, we document that ectodermal BMP4 expression is dependent on Wnt4 signals from the mesoderm. Our results thus reveal a unique role for Wnt4-mediated canonical signaling in the formation and maintenance of the ventral blood island in Xenopus.
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Bian Q, Belmont AS. BAC TG-EMBED: one-step method for high-level, copy-number-dependent, position-independent transgene expression. Nucleic Acids Res 2010; 38:e127. [PMID: 20385594 PMCID: PMC2887973 DOI: 10.1093/nar/gkq178] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Chromosome position effects combined with transgene silencing of multi-copy plasmid insertions lead to highly variable and usually quite low expression levels of mini-genes integrated into mammalian chromosomes. Together, these effects greatly complicate obtaining high-level expression of therapeutic proteins in mammalian cells or reproducible expression of individual or multiple transgenes. Here, we report a simple, one-step procedure for obtaining high-level, reproducible mini-gene expression in mammalian cells. By inserting mini-genes at different locations within a BAC containing the DHFR housekeeping gene locus, we obtain copy-number-dependent, position-independent expression with chromosomal insertions of one to several hundred BAC copies. These multi-copy DHFR BAC insertions adopt similar large-scale chromatin conformations independent of their chromosome integration site, including insertions within centromeric heterochromatin. Prevention of chromosome position effects, therefore, may be the result of embedding the mini-gene within the BAC-specific large-scale chromatin structure. The expression of reporter mini-genes can be stably maintained during continuous, long-term culture in the presence of drug selection. Finally, we show that this method is extendable to reproducible, high-level expression of multiple mini-genes, providing improved expression of both single and multiple transgenes.
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Affiliation(s)
- Qian Bian
- Center for Biophysics and Computational Biology, University of Illinois, Urbana, IL, USA
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19
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Koenig SF, Brentle S, Hamdi K, Fichtner D, Wedlich D, Gradl D. En2, Pax2/5 and Tcf-4 transcription factors cooperate in patterning the Xenopus brain. Dev Biol 2010; 340:318-28. [DOI: 10.1016/j.ydbio.2010.02.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 02/01/2010] [Accepted: 02/10/2010] [Indexed: 11/25/2022]
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20
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Denayer T, Tran HT, Vleminckx K. Transgenic reporter tools tracing endogenous canonical Wnt signaling in Xenopus. Methods Mol Biol 2009; 469:381-400. [PMID: 19109721 DOI: 10.1007/978-1-60327-469-2_24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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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