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Chanda S, Lepikhov K, Dahlem C, Schymik HS, Hoppstädter J, Geber AK, Wagner K, Kessler SM, Empting M, Kiemer AK. Gene Editing and Small Molecule Inhibitors of the RNA Binding Protein IGF2BP2/IMP2 Show its Potential as an Anti-Cancer Drug Target. FRONT BIOSCI-LANDMRK 2024; 29:41. [PMID: 38287808 DOI: 10.31083/j.fbl2901041] [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: 07/24/2023] [Revised: 10/13/2023] [Accepted: 10/26/2023] [Indexed: 01/31/2024]
Abstract
BACKGROUND The RNA-binding protein IGF2BP2/IMP2/VICKZ2/p62 is an oncofetal protein that is overexpressed in several cancer entities. Employing IMP2 knockout colorectal cancer cells, we could show the important role of IMP2 in several hallmarks of cancer. This study aimed to functionally characterize IMP2 in lung (A549, LLC1) and hepatocellular carcinoma (HepG2, Huh7) cell lines to assess its role as a potential target for these cancer entities. METHODS IMP2 knockouts were generated by CRISPR/Cas9 and its variant approach prime editing; the editing efficiency of two single guide RNAs (sgRNAs) was verified via next-generation sequencing. We studied the effect of IMP2 knockout on cell proliferation, colony formation, and migration and employed small-molecule inhibitors of IMP2. RESULTS Despite multiple attempts, it was not possible to generate IMP2 biallelic knockouts in A549 and Huh7 cells. Both sgRNAs showed good editing efficiency. However, edited cells lost their ability to proliferate. The attempt to generate an IMP2 biallelic knockout in LLC1 cells using CRISPR/Cas9 was successful. Monoallelic knockout cell lines of IMP2 showed a reduction in 2D cell proliferation and reduced migration. In 3D cultures, a change in morphology from compact spheroids to loose aggregates and a distinct reduction in the colony formation ability of the IMP2 knockouts was observed, an effect that was mimicked by previously identified IMP2 inhibitor compounds that also showed an inhibitory effect on colony formation. CONCLUSIONS Our in vitro target validation supports that IMP2 is essential for tumor cell proliferation, migration, and colony formation in several cancer entities.
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Affiliation(s)
- Shilpee Chanda
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
| | | | - Charlotte Dahlem
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
| | - Hanna S Schymik
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
| | - Jessica Hoppstädter
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
| | - An-Kristin Geber
- Department of Genetics, Saarland University, 66123 Saarbrücken, Germany
| | - Konrad Wagner
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123 Saarbrücken, Germany
| | - Sonja M Kessler
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
- Halle Research Centre for Drug Therapy (HRCDT), 06120 Halle, Germany
- Institute of Pharmacy, Experimental Pharmacology for Natural Sciences, Martin Luther University Halle-Wittenberg, 06120 Halle, Germany
| | - Martin Empting
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123 Saarbrücken, Germany
| | - Alexandra K Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, 66123 Saarbrücken, Germany
- Center for Gender-Specific Biology and Medicine (CGBM), 66421 Homburg, Germany
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Katzmarski N, Domínguez-Andrés J, Cirovic B, Renieris G, Ciarlo E, Le Roy D, Lepikhov K, Kattler K, Gasparoni G, Händler K, Theis H, Beyer M, van der Meer JWM, Joosten LAB, Walter J, Schultze JL, Roger T, Giamarellos-Bourboulis EJ, Schlitzer A, Netea MG. Author Correction: Transmission of trained immunity and heterologous resistance to infections across generations. Nat Immunol 2023; 24:371-372. [PMID: 36653441 DOI: 10.1038/s41590-023-01426-z] [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: 01/19/2023]
Affiliation(s)
- Natalie Katzmarski
- Quantitative Systems Biology, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Jorge Domínguez-Andrés
- Department of Internal Medicine and Radboud Center for Infectious diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands. .,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.
| | - Branko Cirovic
- Quantitative Systems Biology, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Georgios Renieris
- Department 4th of Internal Medicine, National and Kapodistrian University of Athens, Medical School, Athens, Greece
| | - Eleonora Ciarlo
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital and University of Lausanne, Epalinges, Switzerland
| | - Didier Le Roy
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital and University of Lausanne, Epalinges, Switzerland
| | - Konstantin Lepikhov
- Department of Genetics/Epigenetics, Saarland University, Saarbrücken, Germany
| | - Kathrin Kattler
- Department of Genetics/Epigenetics, Saarland University, Saarbrücken, Germany
| | - Gilles Gasparoni
- Department of Genetics/Epigenetics, Saarland University, Saarbrücken, Germany
| | - Kristian Händler
- Platform for Single Cell Genomics and Epigenomics at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany
| | - Heidi Theis
- Platform for Single Cell Genomics and Epigenomics at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany
| | - Marc Beyer
- Platform for Single Cell Genomics and Epigenomics at the German Center for Neurodegenerative Diseases and the University of Bonn, Bonn, Germany.,Molecular Immunology in Neurodegeneration, German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Jos W M van der Meer
- Department of Internal Medicine and Radboud Center for Infectious diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Leo A B Joosten
- Department of Internal Medicine and Radboud Center for Infectious diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jörn Walter
- Department of Genetics/Epigenetics, Saarland University, Saarbrücken, Germany
| | - Joachim L Schultze
- Molecular Immunology in Neurodegeneration, German Center for Neurodegenerative Diseases, Bonn, Germany.,Department for Genomics & Immunoregulation, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Thierry Roger
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital and University of Lausanne, Epalinges, Switzerland
| | | | - Andreas Schlitzer
- Quantitative Systems Biology, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.,Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.,Department for Immunology & Metabolism, Life and Medical Sciences Institute, University of Bonn, Bonn, Germany
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Nell P, Kattler K, Feuerborn D, Hellwig B, Rieck A, Salhab A, Lepikhov K, Gasparoni G, Thomitzek A, Belgasmi K, Blüthgen N, Morkel M, Küppers-Munther B, Godoy P, Hay DC, Cadenas C, Marchan R, Vartak N, Edlund K, Rahnenführer J, Walter J, Hengstler JG. Identification of an FXR-modulated liver-intestine hybrid state in iPSC-derived hepatocyte-like cells. J Hepatol 2022; 77:1386-1398. [PMID: 35863491 DOI: 10.1016/j.jhep.2022.07.009] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS Pluripotent stem cell (PSC)-derived hepatocyte-like cells (HLC) have enormous potential as a replacement for primary hepatocytes in drug screening, toxicology and cell replacement therapy, but their genome-wide expression patterns differ strongly from primary human hepatocytes (PHH). METHODS We differentiated human induced pluripotent stem cells (hiPSC) via definitive endoderm to HLC and characterized the cells by single-cell and bulk RNA-seq, with complementary epigenetic analyses. We then compared HLC to PHH and publicly available data on human fetal hepatocytes (FH) ex vivo; we performed bioinformatics-guided interventions to improve HLC differentiation via lentiviral transduction of the nuclear receptor FXR and agonist exposure. RESULTS Single-cell RNA-seq revealed that transcriptomes of individual HLC display a hybrid state, where hepatocyte-associated genes are expressed in concert with genes that are not expressed in PHH - mostly intestinal genes - within the same cell. Bulk-level overrepresentation analysis, as well as regulon analysis at the single-cell level, identified sets of regulatory factors discriminating HLC, FH, and PHH, hinting at a central role for the nuclear receptor FXR in the functional maturation of HLC. Combined FXR expression plus agonist exposure enhanced the expression of hepatocyte-associated genes and increased the ability of bile canalicular secretion as well as lipid droplet formation, thereby increasing HLCs' similarity to PHH. The undesired non-liver gene expression was reproducibly decreased, although only by a moderate degree. CONCLUSION In contrast to physiological hepatocyte precursor cells and mature hepatocytes, HLC co-express liver and hybrid genes in the same cell. Targeted modification of the FXR gene regulatory network improves their differentiation by suppressing intestinal traits whilst inducing hepatocyte features. LAY SUMMARY Generation of human hepatocytes from stem cells represents an active research field but its success is hampered by the fact that the stem cell-derived 'hepatocytes' still show major differences to hepatocytes obtained from a liver. Here, we identified an important reason for the difference, specifically that the stem cell-derived 'hepatocyte' represents a hybrid cell with features of hepatocytes and intestinal cells. We show that a specific protein (FXR) suppresses intestinal and induces liver features, thus bringing the stem cell-derived cells closer to hepatocytes derived from human livers.
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Affiliation(s)
- Patrick Nell
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Kathrin Kattler
- Department of Genetics, University of Saarland, 66123 Saarbrücken, Germany
| | - David Feuerborn
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Birte Hellwig
- Department of Statistics, TU Dortmund University, 44221 Dortmund, Germany
| | - Adrian Rieck
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Abdulrahman Salhab
- Department of Genetics, University of Saarland, 66123 Saarbrücken, Germany
| | | | - Gilles Gasparoni
- Department of Genetics, University of Saarland, 66123 Saarbrücken, Germany
| | - Antonia Thomitzek
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Katharina Belgasmi
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Nils Blüthgen
- IRI Life Sciences, Humboldt-Universität zu Berlin, 10117 Berlin, Germany
| | - Markus Morkel
- Institute of Pathology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Barbara Küppers-Munther
- Takara Bio Europe AB (former Cellartis AB), Arvid Wallgrens Backe 20, 41346 Gothenburg, Sweden
| | - Patricio Godoy
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - David C Hay
- Institute of Regeneration and Repair, Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Cristina Cadenas
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Rosemarie Marchan
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Nachiket Vartak
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Karolina Edlund
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany
| | - Jörg Rahnenführer
- Department of Statistics, TU Dortmund University, 44221 Dortmund, Germany
| | - Jörn Walter
- Department of Genetics, University of Saarland, 66123 Saarbrücken, Germany
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors at TU Dortmund, 44139 Dortmund, Germany.
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Dahlem C, Abuhaliema A, Kessler SM, Kröhler T, Zoller BGE, Chanda S, Wu Y, Both S, Müller F, Lepikhov K, Kirsch SH, Laggai S, Müller R, Empting M, Kiemer AK. First Small-Molecule Inhibitors Targeting the RNA-Binding Protein IGF2BP2/IMP2 for Cancer Therapy. ACS Chem Biol 2022; 17:361-375. [PMID: 35023719 DOI: 10.1021/acschembio.1c00833] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The RNA-binding protein IGF2BP2/IMP2/VICKZ2/p62 is overexpressed in several tumor entities, promotes tumorigenesis and tumor progression, and has been suggested to worsen the disease outcome. The aim of this study is to (I) validate IMP2 as a potential target for colorectal cancer, (II) set up a screening assay for small-molecule inhibitors of IMP2, and (III) test the biological activity of the obtained hit compounds. Analyses of colorectal and liver cancer gene expression data showed reduced survival in patients with a high IMP2 expression and in patients with a higher IMP2 expression in advanced tumors. In vitro target validation in 2D and 3D cell cultures demonstrated a reduction in cell viability, migration, and proliferation in IMP2 knockout cells. Also, xenotransplant tumor cell growth in vivo was significantly reduced in IMP2 knockouts. Different compound libraries were screened for IMP2 inhibitors using a fluorescence polarization assay, and the results were confirmed by the thermal shift assay and saturation-transfer difference NMR. Ten compounds, which belong to two classes, that is, benzamidobenzoic acid class and ureidothiophene class, were validated in vitro and showed a biological target specificity. The three most active compounds were also tested in vivo and exhibited reduced tumor xenograft growth in zebrafish embryos. In conclusion, our findings support that IMP2 represents a druggable target to reduce tumor cell proliferation.
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Affiliation(s)
- Charlotte Dahlem
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Ali Abuhaliema
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Sonja M. Kessler
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
- Institute of Pharmacy, Experimental Pharmacology for Natural Sciences, Martin Luther University Halle-Wittenberg, Halle 06108, Germany
| | - Tarek Kröhler
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Ben G. E. Zoller
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Saarbrücken 66123, Germany
| | - Shilpee Chanda
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Yingwen Wu
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Saarbrücken 66123, Germany
| | - Simon Both
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Fabian Müller
- Center for Bioinformatics, Saarland University, Saarbrücken 66123, Germany
| | | | - Susanne H. Kirsch
- Department of Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, Saarland University, Saarbrücken 66123, Germany
| | - Stephan Laggai
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
| | - Rolf Müller
- Department of Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research, Saarland University, Saarbrücken 66123, Germany
- Department of Pharmacy, Saarland University, Saarbrücken 66123, Germany
| | - Martin Empting
- Department of Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarland University, Saarbrücken 66123, Germany
- Department of Pharmacy, Saarland University, Saarbrücken 66123, Germany
| | - Alexandra K. Kiemer
- Department of Pharmacy, Pharmaceutical Biology, Saarland University, Saarbrücken 66123, Germany
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5
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Behjati Ardakani F, Kattler K, Heinen T, Schmidt F, Feuerborn D, Gasparoni G, Lepikhov K, Nell P, Hengstler J, Walter J, Schulz MH. Prediction of single-cell gene expression for transcription factor analysis. Gigascience 2020; 9:giaa113. [PMID: 33124660 PMCID: PMC7596801 DOI: 10.1093/gigascience/giaa113] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 03/11/2020] [Revised: 08/20/2020] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Single-cell RNA sequencing is a powerful technology to discover new cell types and study biological processes in complex biological samples. A current challenge is to predict transcription factor (TF) regulation from single-cell RNA data. RESULTS Here, we propose a novel approach for predicting gene expression at the single-cell level using cis-regulatory motifs, as well as epigenetic features. We designed a tree-guided multi-task learning framework that considers each cell as a task. Through this framework we were able to explain the single-cell gene expression values using either TF binding affinities or TF ChIP-seq data measured at specific genomic regions. TFs identified using these models could be validated by the literature. CONCLUSION Our proposed method allows us to identify distinct TFs that show cell type-specific regulation. This approach is not limited to TFs but can use any type of data that can potentially be used in explaining gene expression at the single-cell level to study factors that drive differentiation or show abnormal regulation in disease. The implementation of our workflow can be accessed under an MIT license via https://github.com/SchulzLab/Triangulate.
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Affiliation(s)
- Fatemeh Behjati Ardakani
- Institute for Cardiovascular Regeneration, Goethe University, 60590 Frankfurt am Main, Germany; Theodor-Stern-Kai 7
- Cluster of Excellence MMCI, Saarland University, Campus E1 7, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Max Planck Institute for Informatics, Campus E1 4, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Graduate School of Computer Science, Saarland University, Campus E1 3, Saarbrücken, Germany
| | - Kathrin Kattler
- Department of Genetics, Saarland University, Campus A2 4, 66123 Saarbrücken, Germany
| | - Tobias Heinen
- Cluster of Excellence MMCI, Saarland University, Campus E1 7, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Max Planck Institute for Informatics, Campus E1 4, Saarland Informatics Campus, 66123 Saarbrücken, Germany
| | - Florian Schmidt
- Institute for Cardiovascular Regeneration, Goethe University, 60590 Frankfurt am Main, Germany; Theodor-Stern-Kai 7
- Cluster of Excellence MMCI, Saarland University, Campus E1 7, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Max Planck Institute for Informatics, Campus E1 4, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Graduate School of Computer Science, Saarland University, Campus E1 3, Saarbrücken, Germany
| | - David Feuerborn
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystraße 67, 44139 Dortmund, Germany
| | - Gilles Gasparoni
- Department of Genetics, Saarland University, Campus A2 4, 66123 Saarbrücken, Germany
| | - Konstantin Lepikhov
- Department of Genetics, Saarland University, Campus A2 4, 66123 Saarbrücken, Germany
| | - Patrick Nell
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystraße 67, 44139 Dortmund, Germany
| | - Jan Hengstler
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystraße 67, 44139 Dortmund, Germany
| | - Jörn Walter
- Department of Genetics, Saarland University, Campus A2 4, 66123 Saarbrücken, Germany
| | - Marcel H Schulz
- Institute for Cardiovascular Regeneration, Goethe University, 60590 Frankfurt am Main, Germany; Theodor-Stern-Kai 7
- Cluster of Excellence MMCI, Saarland University, Campus E1 7, Saarland Informatics Campus, 66123 Saarbrücken, Germany
- Max Planck Institute for Informatics, Campus E1 4, Saarland Informatics Campus, 66123 Saarbrücken, Germany
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Giehr P, Kyriakopoulos C, Lepikhov K, Wallner S, Wolf V, Walter J. Two are better than one: HPoxBS - hairpin oxidative bisulfite sequencing. Nucleic Acids Res 2019; 46:e88. [PMID: 29912476 PMCID: PMC6125676 DOI: 10.1093/nar/gky422] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 02/22/2018] [Accepted: 06/13/2018] [Indexed: 12/30/2022] Open
Abstract
The controlled and stepwise oxidation of 5mC to 5hmC, 5fC and 5caC by Tet enzymes is influencing the chemical and biological properties of cytosine. Besides direct effects on gene regulation, oxidised forms influence the dynamics of demethylation and re-methylation processes. So far, no combined methods exist which allow to precisely determine the strand specific localisation of cytosine modifications along with their CpG symmetric distribution. Here we describe a comprehensive protocol combining conventional hairpin bisulfite with oxidative bisulfite sequencing (HPoxBS) to determine the strand specific distribution of 5mC and 5hmC at base resolution. We apply this method to analyse the contribution of local oxidative effects on DNA demethylation in mouse ES cells. Our method includes the HPoxBS workflow and subsequent data analysis using our developed software tools. Besides a precise estimation and display of strand specific 5mC and 5hmC levels at base resolution we apply the data to predict region specific activities of Dnmt and Tet enzymes. Our experimental and computational workflow provides a precise double strand display of 5mC and 5hmC modifications at single base resolution. Based on our data we predict region specific Tet and Dnmt enzyme efficiencies shaping the distinct locus levels and patterns of 5hmC and 5mC.
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Affiliation(s)
- Pascal Giehr
- Department of Biological Sciences, Saarland University, Campus A2.4, 66123 Saarbrücken, Saarland, Germany
| | | | - Konstantin Lepikhov
- Department of Biological Sciences, Saarland University, Campus A2.4, 66123 Saarbrücken, Saarland, Germany
| | - Stefan Wallner
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Bayern, Germany
| | - Verena Wolf
- Computer Science Department, Saarland University, Campus E1.3, 66123 Saarbrücken, Saarland, Germany
| | - Jörn Walter
- Department of Biological Sciences, Saarland University, Campus A2.4, 66123 Saarbrücken, Saarland, Germany
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7
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Lan J, Lepikhov K, Giehr P, Walter J. Histone and DNA methylation control by H3 serine 10/threonine 11 phosphorylation in the mouse zygote. Epigenetics Chromatin 2017; 10:5. [PMID: 28228845 PMCID: PMC5307733 DOI: 10.1186/s13072-017-0112-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 08/31/2016] [Accepted: 01/23/2017] [Indexed: 11/22/2022] Open
Abstract
Background
In the mammalian zygote, epigenetic reprogramming is a tightly controlled process of coordinated alterations of histone and DNA modifications. The parental genomes of the zygote show distinct patterns of histone H3 variants and distinct patterns of DNA and histone modifications. The molecular mechanisms linking histone variant-specific modifications and DNA methylation reprogramming during the first cell cycle remain to be clarified. Results Here, we show that the degree and distribution of H3K9me2 and of DNA modifications (5mC/5hmC) are influenced by the phosphorylation status of H3S10 and H3T11. The overexpression of the mutated histone variants H3.1 and 3.2 at either serine 10 or threonine 11 causes a decrease in H3K9me2 and 5mC and a concomitant increase in 5hmC in the maternal genome. Bisulphite sequencing results indicate an increase in hemimethylated CpG positions following H3.1T10A overexpression suggesting an impact of H3S10 and H3T11 phosphorylation on DNA methylation maintenance. Conclusions Our data suggest a crosstalk between the cell-cycle-dependent control of S10 and T11 phosphorylation of histone variants H3.1 and H3.2 and the maintenance of the heterochromatic mark H3K9me2. This histone H3 “phospho-methylation switch” also influences the oxidative control of DNA methylation in the mouse zygote. Electronic supplementary material The online version of this article (doi:10.1186/s13072-017-0112-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jie Lan
- FR 8.3, Biological Sciences, Genetics/Epigenetics, University of Saarland, Campus A2.4, 66123 Saarbrücken, Germany.,Faculty of Medicine, Free University of Brussels, C.P. 614, Building GE, 5th floor, 808 Route de Lennik, 1070 Brussels, Belgium
| | - Konstantin Lepikhov
- FR 8.3, Biological Sciences, Genetics/Epigenetics, University of Saarland, Campus A2.4, 66123 Saarbrücken, Germany
| | - Pascal Giehr
- FR 8.3, Biological Sciences, Genetics/Epigenetics, University of Saarland, Campus A2.4, 66123 Saarbrücken, Germany
| | - Joern Walter
- FR 8.3, Biological Sciences, Genetics/Epigenetics, University of Saarland, Campus A2.4, 66123 Saarbrücken, Germany
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8
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Arand J, Wossidlo M, Lepikhov K, Peat JR, Reik W, Walter J. Selective impairment of methylation maintenance is the major cause of DNA methylation reprogramming in the early embryo. Epigenetics Chromatin 2015; 8:1. [PMID: 25621012 PMCID: PMC4304184 DOI: 10.1186/1756-8935-8-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [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: 09/19/2014] [Accepted: 11/26/2014] [Indexed: 11/28/2022] Open
Abstract
Background DNA methylomes are extensively reprogrammed during mouse pre-implantation and early germ cell development. The main feature of this reprogramming is a genome-wide decrease in 5-methylcytosine (5mC). Standard high-resolution single-stranded bisulfite sequencing techniques do not allow discrimination of the underlying passive (replication-dependent) or active enzymatic mechanisms of 5mC loss. We approached this problem by generating high-resolution deep hairpin bisulfite sequencing (DHBS) maps, allowing us to follow the patterns of symmetric DNA methylation at CpGs dyads on both DNA strands over single replications. Results We compared DHBS maps of repetitive elements in the developing zygote, the early embryo, and primordial germ cells (PGCs) at defined stages of development. In the zygote, we observed distinct effects in paternal and maternal chromosomes. A significant loss of paternal DNA methylation was linked to replication and to an increase in continuous and dispersed hemimethylated CpG dyad patterns. Overall methylation levels at maternal copies remained largely unchanged, but showed an increased level of dispersed hemi-methylated CpG dyads. After the first cell cycle, the combined DHBS patterns of paternal and maternal chromosomes remained unchanged over the next three cell divisions. By contrast, in PGCs the DNA demethylation process was continuous, as seen by a consistent decrease in fully methylated CpG dyads over consecutive cell divisions. Conclusions The main driver of DNA demethylation in germ cells and in the zygote is partial impairment of maintenance of symmetric DNA methylation at CpG dyads. In the embryo, this passive demethylation is restricted to the first cell division, whereas it continues over several cell divisions in germ cells. The dispersed patterns of CpG dyads in the early-cleavage embryo suggest a continuous partial (and to a low extent active) loss of methylation apparently compensated for by selective de novo methylation. We conclude that a combination of passive and active demethylation events counteracted by de novo methylation are involved in the distinct reprogramming dynamics of DNA methylomes in the zygote, the early embryo, and PGCs. Electronic supplementary material The online version of this article (doi:10.1186/1756-8935-8-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julia Arand
- University of Saarland, FR 8.3, Biological Sciences, Genetics/Epigenetics, Campus A2.4, 66123 Saarbrücken, Germany ; Departments of Pediatrics and Genetics, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305 USA
| | - Mark Wossidlo
- University of Saarland, FR 8.3, Biological Sciences, Genetics/Epigenetics, Campus A2.4, 66123 Saarbrücken, Germany ; Departments of Genetics and Obstetrics & Gynaecology, Stanford University School of Medicine, Institute for Stem Cell Biology & Regenerative Medicine, 265 Campus Drive, Stanford, CA 94305 USA
| | - Konstantin Lepikhov
- University of Saarland, FR 8.3, Biological Sciences, Genetics/Epigenetics, Campus A2.4, 66123 Saarbrücken, Germany
| | - Julian R Peat
- Epigenetics Programme, The Babraham Institute, Cambridge, CB22 3AT UK
| | - Wolf Reik
- Epigenetics Programme, The Babraham Institute, Cambridge, CB22 3AT UK ; Wellcome Trust Sanger Institute, Hinxton, CB10 1SA UK
| | - Jörn Walter
- University of Saarland, FR 8.3, Biological Sciences, Genetics/Epigenetics, Campus A2.4, 66123 Saarbrücken, Germany
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Unterberg M, Leffers L, Hübner F, Humpf HU, Lepikhov K, Walter J, Ebert F, Schwerdtle T. Toxicity of arsenite and thio-DMAV after long-term (21 days) incubation of human urothelial cells: cytotoxicity, genotoxicity and epigenetics. Toxicol Res (Camb) 2014. [DOI: 10.1039/c4tx00036f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
This study aims to further mechanistically understand toxic modes of action after chronic arsenic species exposure.
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Affiliation(s)
- Marlies Unterberg
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Nutritional Sciences
- University of Potsdam
| | - Larissa Leffers
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
| | - Florian Hübner
- Institute of Food Chemistry
- WWU Muenster
- 48149 Muenster, Germany
| | - Hans-Ulrich Humpf
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Food Chemistry
- WWU Muenster
| | - Konstantin Lepikhov
- Department of Genetics/Epigenetics
- Campus Saarbruecken
- Saarland University
- 66123 Saarbruecken, Germany
| | - Jörn Walter
- Department of Genetics/Epigenetics
- Campus Saarbruecken
- Saarland University
- 66123 Saarbruecken, Germany
| | - Franziska Ebert
- Institute of Nutritional Sciences
- University of Potsdam
- 14558 Nuthetal, Germany
| | - Tanja Schwerdtle
- Graduate School of Chemistry
- WWU Muenster
- 48149 Muenster, Germany
- Institute of Nutritional Sciences
- University of Potsdam
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Habibi E, Brinkman AB, Arand J, Kroeze LI, Kerstens HHD, Matarese F, Lepikhov K, Gut M, Brun-Heath I, Hubner NC, Benedetti R, Altucci L, Jansen JH, Walter J, Gut IG, Marks H, Stunnenberg HG. Whole-genome bisulfite sequencing of two distinct interconvertible DNA methylomes of mouse embryonic stem cells. Cell Stem Cell 2013; 13:360-9. [PMID: 23850244 DOI: 10.1016/j.stem.2013.06.002] [Citation(s) in RCA: 336] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 06/03/2013] [Accepted: 06/07/2013] [Indexed: 12/22/2022]
Abstract
The use of two kinase inhibitors (2i) enables derivation of mouse embryonic stem cells (ESCs) in the pluripotent ground state. Using whole-genome bisulfite sequencing (WGBS), we show that male 2i ESCs are globally hypomethylated compared to conventional ESCs maintained in serum. In serum, female ESCs are hypomethyated similarly to male ESCs in 2i, and DNA methylation is further reduced in 2i. Regions with elevated DNA methylation in 2i strongly correlate with the presence of H3K9me3 on endogenous retroviruses (ERVs) and imprinted loci. The methylome of male ESCs in serum parallels postimplantation blastocyst cells, while 2i stalls ESCs in a hypomethylated, ICM-like state. WGBS analysis during adaptation of 2i ESCs to serum suggests that deposition of DNA methylation is largely random, while loss of DNA methylation during reversion to 2i occurs passively, initiating at TET1 binding sites. Together, our analysis provides insight into DNA methylation dynamics in cultured ESCs paralleling early developmental processes.
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Affiliation(s)
- Ehsan Habibi
- Department of Molecular Biology, Faculty of Science, Nijmegen Centre for Molecular Life Sciences NCMLS, Radboud University, 6525GA, Nijmegen, The Netherlands
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Wossidlo M, Nakamura T, Lepikhov K, Marques CJ, Zakhartchenko V, Boiani M, Arand J, Nakano T, Reik W, Walter J. 5-Hydroxymethylcytosine in the mammalian zygote is linked with epigenetic reprogramming. Nat Commun 2011; 2:241. [DOI: 10.1038/ncomms1240] [Citation(s) in RCA: 612] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 02/16/2011] [Indexed: 12/24/2022] Open
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Lepikhov K, Wossidlo M, Arand J, Walter J. DNA methylation reprogramming and DNA repair in the mouse zygote. Int J Dev Biol 2010; 54:1565-74. [DOI: 10.1387/ijdb.103206kl] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Peters DD, Lepikhov K, Rodenacker K, Marschall S, Boersma A, Hutzler P, Scherb H, Walter J, Hrabé de Angelis M. Effect of IVF and laser zona dissection on DNA methylation pattern of mouse zygotes. Mamm Genome 2009; 20:664-73. [DOI: 10.1007/s00335-009-9227-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 09/04/2009] [Indexed: 01/08/2023]
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Racedo SE, Wrenzycki C, Lepikhov K, Salamone D, Walter J, Niemann H. Epigenetic modifications and related mRNA expression during bovine oocyte in vitro maturation. Reprod Fertil Dev 2009; 21:738-48. [DOI: 10.1071/rd09039] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Accepted: 05/03/2009] [Indexed: 11/23/2022] Open
Abstract
The present study investigated the global pattern of two histone modifications and methylation of DNA during in vitro maturation of bovine oocytes retrieved from follicles of two different sizes (<2 mm and 2–8 mm). The methylation status of histone H3 at position lysine K9 (H3K9 me2), the acetylation status of histone H4 at position lysine K12 (H4K12ac) and the methylation of DNA were assessed by immunocytochemistry. In parallel, the relative abundance of mRNAs coding for proteins specifically involved in reprogramming, including HLA-B associated transcript 8 (G9A), suppressor of variegation 3-9 homolog 1 (SUV39H1), the somatic isoform of DNA methyltransferase 1 (DNMT1), DNA methyltransferase 3b (DNMT3b) and zygote arrest 1 (ZAR1) was determined by RT-PCR. The α-H3K9 me2 signal was present in the GV stage and remained detectable until the end of the maturation period. α-H4K12ac antibody gave a stronger signal in GV and GVBD oocytes and markedly decreased after GVBD. The signal showing the methylation of DNA was present during the entire maturation period. The five transcripts showed a gene-specific expression profile. Results revealed the global patterns of H3K9 me2, H4K12ac, DNA methylation and the mRNA pool profiles of genes critically involved in epigenetic modifications during bovine oocyte maturation and their possible relationship with the acquisition of oocyte developmental competence and follicular development.
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Lepikhov K, Zakhartchenko V, Hao R, Yang F, Wrenzycki C, Niemann H, Wolf E, Walter J. Evidence for conserved DNA and histone H3 methylation reprogramming in mouse, bovine and rabbit zygotes. Epigenetics Chromatin 2008; 1:8. [PMID: 19014417 PMCID: PMC2590599 DOI: 10.1186/1756-8935-1-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [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: 06/26/2008] [Accepted: 11/03/2008] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND In mammals the parental genomes are epigenetically reprogrammed after fertilization. This reprogramming includes a rapid demethylation of the paternal (sperm-derived) chromosomes prior to DNA replication in zygotes. Such active DNA demethylation in the zygote has been documented for several mammalian species, including mouse, rat, pig, human and cow, but questioned to occur in rabbit. RESULTS When comparing immunohistochemical patterns of antibodies against 5-methyl-cytosine, H3K4me3 and H3K9me2 modifications we observe similar pronuclear distribution and dynamics in mouse, bovine and rabbit zygotes. In rabbit DNA demethylation of the paternal chromosomes occurs at slightly advanced pronuclear stages. We also show that the rabbit oocyte rapidly demethylates DNA of donor fibroblast after nuclear transfer. CONCLUSION Our data reveal that major events of epigenetic reprogramming during pronuclear maturation, including mechanisms of active DNA demethylation, are apparently conserved among mammalian species.
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Affiliation(s)
- Konstantin Lepikhov
- University of Saarland, Natural Sciences - Technical Faculty III, Biological Sciences, Genetics/Epigenetics, 66123 Saarbrücken, Germany.
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Lepikhov K, Zakhartchenko V, Yang F, Wrenzycki C, Wolf E, Walter J. 110 COMPARATIVE ANALYSIS OF DNA AND HISTONE H3 METHYLATION REPROGRAMMING IN MOUSE, BOVINE, AND RABBIT ZYGOTES. Reprod Fertil Dev 2008. [DOI: 10.1071/rdv20n1ab110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Active demethylation of paternal DNA in zygotes has been documented for many mammalian species, including mouse (Mayer et al. 2000 Nature 403, 501–505), rat (Zaitseva et al. 2007 Mol. Reprod. Dev. 74, 1255–1261), pig (Fulka et al. 2006 Histochem. Cell. Biol. 126, 213–217), Homo sapiens (Fulka et al. 2004 Reproduction 128, 703–708), and cow (Beaujean et al. 2004 Curr. Biol. 14, 266–267). The generality of this concept has been challenged by reports stating that there is no detectable genome-wide paternal DNA demethylation in rabbit (Shi et al. 2004 Biol. Reprod. 71, 340–347) and ovine (Beaujean et al. 2004 Curr. Biol. 14, 266–267), whereas others report partial evidence for the opposite (Zhang et al. 2005 Mol. Reprod. Dev. 72, 530–533). In order to compare the fate of DNA and histone H3 methylation (H3/K4triMe and H3/K9diMe), we performed studies on mouse, bovine, and rabbit zygotes using specific antibodies in an indirect immunofluorescence approach. We observed a similar distribution of these epigenetic modifications in maternal and paternal pronuclei of the zygote, indicating that the overall epigenetic reprogramming activities — including the DNA demethylation of the paternal pronucleus — are conserved between mammalian species. For all 3 species we found a clear asymmetry in mouse monoclonal antimethylcytosine (MeC) antibody signal intensities between paternal and maternal pronuclei at advanced stages, which suggests the presence of paternal DNA demethylation. To obtain additional evidence for the presence of DNA demethylation activity in rabbit zygotes, we examined 1-cell embryos after somatic cell nuclear transfer (SCNT) using rabbit fetal fibroblasts as nuclear donors, and we found a strong signal reduction in SCNT embryos 4 h after activation. For the majority of SCNT 1-cell embryos, we estimated at least a 4- to 6-fold decrease of MeC signal. Along with the similarities of DNA demethylation kinetics in rabbit, mouse, and bovine zygotes, we found a conserved distribution of H3/K4triMe and H3/K9diMe signals on maternal and paternal chromatin. In all 3 species, H3/K4triMe, which predominantly demarcate open chromatin, is present in both pronuclear chromatin, whereas H3/K9diMe, a hallmark of condensed chromatin, is strongly enriched in maternal pronuclear chromatin and undetectable in paternal chromatin. Furthermore, we observed a similar asymmetric compartmentalization of paternal and maternal chromosomes in early 2-cell rabbit and bovine embryos as monitored by H3/K9diMe, which marks maternally derived chromosomes. In summary, our data suggest that mechanisms of epigenetic reprogramming are conserved in mammalian species both on the level of DNA and chromatin methylation.
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Lepikhov K, Yang F, Wrenzycki C, Zakhartchenko V, Niemann H, Wolf E, Walter J. 131 DYNAMICS OF HISTONE H3 METHYLATION AT POSITIONS K4 AND K9 IN MOUSE, RABBIT, AND BOVINE PRE-IMPLANTATION EMBRYOS. Reprod Fertil Dev 2006. [DOI: 10.1071/rdv18n2ab131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In mammals, upon the penetration of sperm into the oocyte, the paternal genome undergoes dramatic epigenetic changes. Protamin packaging of DNA is replaced by histones that acquire specific modifications. In mouse zygotes, paternal DNA gets rapidly demethylated by an active mechanism. In bovine zygotes the methylation from paternal DNA is erased only partially, and in rabbit zygotes it persists at the initial level. To understand whether these reprogramming differences are also reflected in histone modifications, we examined the dynamic changes of histone H3 methylation at positions K4 and K9 in mouse, bovine, and rabbit zygotes and in preimplantation embryos using an immunofluorescence staining procedure (Lepikhov and Walter 2004 BMC Dev. Biol. 4, 12). In zygotes, maternal chromatin contains both types of histone H3 methylation. After fertilization protamines in sperm are very quickly replaced by histones. After the formation of nucleosomes, histone H3 acquires methylation at position K4 in a stepwise manner: first as mono-methylated form and later as tri-methylated. In the late zygote, both paternal and maternal pronuclei show equal levels of histone H3 methylation at position K4. Regardless of the differences in DNA reprogramming in these 3 species, H3/K9 di-methylation is not detected on paternal genomes and is only associated with maternal genomes. During the subsequent cleavage stages, H3/K9 di-methylation decreases gradually and becomes hardly detectable in 4-cell bovine and rabbit embryos. In mouse embryos, it is detectable through all the stages. Bovine embryos reacquire this type of modification at the 8-16 cell stage, and it remains at the very low levels in rabbit, embryos until the blastocyst stage. In conclusion, mouse, rabbit and bovine zygotes show similar patterns of H3/K4triMe and H3/K9diMe distribution despite the difference in paternal DNA demethylation. The dynamics of H3/K9diMe distribution patterns in cleavage stage embryos from all embryos do not correlate with embryonic genomic activation events.
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Lepikhov K, Walter J. Differential dynamics of histone H3 methylation at positions K4 and K9 in the mouse zygote. BMC Dev Biol 2004; 4:12. [PMID: 15383155 PMCID: PMC521682 DOI: 10.1186/1471-213x-4-12] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Accepted: 09/21/2004] [Indexed: 01/12/2023]
Abstract
Background In the mouse zygote the paternal genome undergoes dramatic structural and epigenetic changes. Chromosomes are decondensed, protamines replaced by histones and DNA is rapidly and actively demethylated. The epigenetic asymmetry between parental genomes remains at least until the 2-cell stage suggesting functional differences between paternal and maternal genomes during early cleavage stages. Results Here we analyzed the timing of histone deposition on the paternal pronucleus and the dynamics of histone H3 methylation (H3/K4mono-, H3/K4tri- and H3/K9di-methylation) immediately after fertilization. Whereas maternal chromatin maintains all types of histone H3 methylation throughout the zygotic development, paternal chromosomes acquire new and unmodified histones shortly after fertilization. In the following hours we observe a gradual increase in H3/K4mono-methylation whereas H3/K4tri-methylation is not present before latest pronuclear stages. Histone H3/K9di-methylation is completely absent from the paternal pronucleus, including metaphase chromosomes of the first mitotic stage. Conclusion Parallel to the epigenetic asymmetry in DNA methylation, chromatin modifications are also different between both parental genomes in the very first hours post fertilization. Whereas methylation at H3/K4 gradually becomes similar between both genomes, H3/K9 methylation remains asymmetric.
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Affiliation(s)
- Konstantin Lepikhov
- Department of Natural Sciences – Technical Faculty III FR 8.3, Biological Sciences, Institute of Genetics/Epigenetics, University of Saarland, Saarbrücken, Germany
| | - Jörn Walter
- Department of Natural Sciences – Technical Faculty III FR 8.3, Biological Sciences, Institute of Genetics/Epigenetics, University of Saarland, Saarbrücken, Germany
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Lepikhov K, Tchernov A, Zheleznaja L, Matvienko N, Walter J, Trautner TA. Characterization of the type IV restriction modification system BspLU11III from Bacillus sp. LU11. Nucleic Acids Res 2001; 29:4691-8. [PMID: 11713319 PMCID: PMC92511 DOI: 10.1093/nar/29.22.4691] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the characterization and cloning of the genes for an unusual type IV restriction-modification system, BspLU11III, from Bacillus sp. LU11. The system consists of two methyltransferases and one endonuclease, which also possesses methyltransferase activity. The three genes of the restriction-modification system, bsplu11IIIMa, bsplu11IIIMb and bsplu11IIIR, are closely linked and tandemly arranged. The corresponding enzymes recognize the dsDNA sequence 5'-GGGAC-3'/5'-GTCCC-3', with M.BspLU11IIIa modifying the A (underlined) of one strand and M.BspLU11IIIb the inner C (underlined) of the other strand. R.BspLU11III has both endonuclease and adenine-specific methyltransferase activities and is able to protect the DNA against cleavage by itself. In contrast to all type IV restriction-modification systems described so far, which have only one adenine-specific methyltransferase, BspLU11III is the first type IV restriction-modification system that includes two methyltransferases, one of them being cytosine specific.
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Affiliation(s)
- K Lepikhov
- Institute of Protein Research, 142292 Pushchino, Moscow Region, Russia
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