1
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Afanasyev AY, Kim Y, Tolokh IS, Sharakhov IV, Onufriev AV. The probability of chromatin to be at the nuclear lamina has no systematic effect on its transcription level in fruit flies. Epigenetics Chromatin 2024; 17:13. [PMID: 38705995 PMCID: PMC11071202 DOI: 10.1186/s13072-024-00528-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/08/2024] [Indexed: 05/07/2024] Open
Abstract
BACKGROUND Multiple studies have demonstrated a negative correlation between gene expression and positioning of genes at the nuclear envelope (NE) lined by nuclear lamina, but the exact relationship remains unclear, especially in light of the highly stochastic, transient nature of the gene association with the NE. RESULTS In this paper, we ask whether there is a causal, systematic, genome-wide relationship between the expression levels of the groups of genes in topologically associating domains (TADs) of Drosophila nuclei and the probabilities of TADs to be found at the NE. To investigate the nature of this possible relationship, we combine a coarse-grained dynamic model of the entire Drosophila nucleus with genome-wide gene expression data; we analyze the TAD averaged transcription levels of genes against the probabilities of individual TADs to be in contact with the NE in the control and lamins-depleted nuclei. Our findings demonstrate that, within the statistical error margin, the stochastic positioning of Drosophila melanogaster TADs at the NE does not, by itself, systematically affect the mean level of gene expression in these TADs, while the expected negative correlation is confirmed. The correlation is weak and disappears completely for TADs not containing lamina-associated domains (LADs) or TADs containing LADs, considered separately. Verifiable hypotheses regarding the underlying mechanism for the presence of the correlation without causality are discussed. These include the possibility that the epigenetic marks and affinity to the NE of a TAD are determined by various non-mutually exclusive mechanisms and remain relatively stable during interphase. CONCLUSIONS At the level of TADs, the probability of chromatin being in contact with the nuclear envelope has no systematic, causal effect on the transcription level in Drosophila. The conclusion is reached by combining model-derived time-evolution of TAD locations within the nucleus with their experimental gene expression levels.
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Affiliation(s)
- Alexander Y Afanasyev
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Yoonjin Kim
- Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Igor S Tolokh
- Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA
| | - Igor V Sharakhov
- Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
| | - Alexey V Onufriev
- Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
- Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
- Center for Soft Matter and Biological Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, USA.
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2
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Willemin A, Szabó D, Pombo A. Epigenetic regulatory layers in the 3D nucleus. Mol Cell 2024; 84:415-428. [PMID: 38242127 PMCID: PMC10872226 DOI: 10.1016/j.molcel.2023.12.032] [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: 07/26/2023] [Revised: 11/21/2023] [Accepted: 12/15/2023] [Indexed: 01/21/2024]
Abstract
Nearly 7 decades have elapsed since Francis Crick introduced the central dogma of molecular biology, as part of his ideas on protein synthesis, setting the fundamental rules of sequence information transfer from DNA to RNAs and proteins. We have since learned that gene expression is finely tuned in time and space, due to the activities of RNAs and proteins on regulatory DNA elements, and through cell-type-specific three-dimensional conformations of the genome. Here, we review major advances in genome biology and discuss a set of ideas on gene regulation and highlight how various biomolecular assemblies lead to the formation of structural and regulatory features within the nucleus, with roles in transcriptional control. We conclude by suggesting further developments that will help capture the complex, dynamic, and often spatially restricted events that govern gene expression in mammalian cells.
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Affiliation(s)
- Andréa Willemin
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Architecture Group, Berlin, Germany; Humboldt-Universität zu Berlin, Institute for Biology, Berlin, Germany.
| | - Dominik Szabó
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Architecture Group, Berlin, Germany; Humboldt-Universität zu Berlin, Institute for Biology, Berlin, Germany
| | - Ana Pombo
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Architecture Group, Berlin, Germany; Humboldt-Universität zu Berlin, Institute for Biology, Berlin, Germany.
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3
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Shevelyov YY. Interactions of Chromatin with the Nuclear Lamina and Nuclear Pore Complexes. Int J Mol Sci 2023; 24:15771. [PMID: 37958755 PMCID: PMC10649103 DOI: 10.3390/ijms242115771] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 10/26/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023] Open
Abstract
Heterochromatin and euchromatin form different spatial compartments in the interphase nucleus, with heterochromatin being localized mainly at the nuclear periphery. The mechanisms responsible for peripheral localization of heterochromatin are still not fully understood. The nuclear lamina and nuclear pore complexes were obvious candidates for the role of heterochromatin binders. This review is focused on recent studies showing that heterochromatin interactions with the nuclear lamina and nuclear pore complexes maintain its peripheral localization. Differences in chromatin interactions with the nuclear envelope in cell populations and in individual cells are also discussed.
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Affiliation(s)
- Yuri Y Shevelyov
- Laboratory of Analysis of Gene Regulation, National Research Centre "Kurchatov Institute", Kurchatov Sq. 2, 123182 Moscow, Russia
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4
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Martino S, Carollo PS, Barra V. A Glimpse into Chromatin Organization and Nuclear Lamina Contribution in Neuronal Differentiation. Genes (Basel) 2023; 14:genes14051046. [PMID: 37239406 DOI: 10.3390/genes14051046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
During embryonic development, stem cells undergo the differentiation process so that they can specialize for different functions within the organism. Complex programs of gene transcription are crucial for this process to happen. Epigenetic modifications and the architecture of chromatin in the nucleus, through the formation of specific regions of active as well as inactive chromatin, allow the coordinated regulation of the genes for each cell fate. In this mini-review, we discuss the current knowledge regarding the regulation of three-dimensional chromatin structure during neuronal differentiation. We also focus on the role the nuclear lamina plays in neurogenesis to ensure the tethering of the chromatin to the nuclear envelope.
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Affiliation(s)
- Salvatore Martino
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
| | - Pietro Salvatore Carollo
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
- Institute of Molecular Bioimaging and Physiology, National Research Council (IBFM-CNR), 90015 Cefalù, Italy
| | - Viviana Barra
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, 90128 Palermo, Italy
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5
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Martin S, Poppe D, Olova N, O'Leary C, Ivanova E, Pflueger J, Dechka J, Simmons RK, Cooper HM, Reik W, Lister R, Wolvetang EJ. Embryonic Stem Cell-Derived Neurons as a Model System for Epigenome Maturation during Development. Genes (Basel) 2023; 14:genes14050957. [PMID: 37239317 DOI: 10.3390/genes14050957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/16/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
DNA methylation in neurons is directly linked to neuronal genome regulation and maturation. Unlike other tissues, vertebrate neurons accumulate high levels of atypical DNA methylation in the CH sequence context (mCH) during early postnatal brain development. Here, we investigate to what extent neurons derived in vitro from both mouse and human pluripotent stem cells recapitulate in vivo DNA methylation patterns. While human ESC-derived neurons did not accumulate mCH in either 2D culture or 3D organoid models even after prolonged culture, cortical neurons derived from mouse ESCs acquired in vivo levels of mCH over a similar time period in both primary neuron cultures and in vivo development. mESC-derived neuron mCH deposition was coincident with a transient increase in Dnmt3a, preceded by the postmitotic marker Rbfox3 (NeuN), was enriched at the nuclear lamina, and negatively correlated with gene expression. We further found that methylation patterning subtly differed between in vitro mES-derived and in vivo neurons, suggesting the involvement of additional noncell autonomous processes. Our findings show that mouse ESC-derived neurons, in contrast to those of humans, can recapitulate the unique DNA methylation landscape of adult neurons in vitro over experimentally tractable timeframes, which allows their use as a model system to study epigenome maturation over development.
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Affiliation(s)
- Sally Martin
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Daniel Poppe
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Nelly Olova
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
| | - Conor O'Leary
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Elena Ivanova
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
| | - Jahnvi Pflueger
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Jennifer Dechka
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rebecca K Simmons
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Helen M Cooper
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wolf Reik
- Epigenetics ISP, The Babraham Institute, Cambridge CB22 3AT, UK
- The Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
| | - Ryan Lister
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
- Harry Perkins Institute of Medical Research, Perth, WA 6009, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
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6
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González L, Kolbin D, Trahan C, Jeronimo C, Robert F, Oeffinger M, Bloom K, Michnick SW. Adaptive partitioning of a gene locus to the nuclear envelope in Saccharomyces cerevisiae is driven by polymer-polymer phase separation. Nat Commun 2023; 14:1135. [PMID: 36854718 PMCID: PMC9975218 DOI: 10.1038/s41467-023-36391-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 01/30/2023] [Indexed: 03/03/2023] Open
Abstract
Partitioning of active gene loci to the nuclear envelope (NE) is a mechanism by which organisms increase the speed of adaptation and metabolic robustness to fluctuating resources in the environment. In the yeast Saccharomyces cerevisiae, adaptation to nutrient depletion or other stresses, manifests as relocalization of active gene loci from nucleoplasm to the NE, resulting in more efficient transport and translation of mRNA. The mechanism by which this partitioning occurs remains a mystery. Here, we demonstrate that the yeast inositol depletion-responsive gene locus INO1 partitions to the nuclear envelope, driven by local histone acetylation-induced polymer-polymer phase separation from the nucleoplasmic phase. This demixing is consistent with recent evidence for chromatin phase separation by acetylation-mediated dissolution of multivalent histone association and fits a physical model where increased bending stiffness of acetylated chromatin polymer causes its phase separation from de-acetylated chromatin. Increased chromatin spring stiffness could explain nucleation of transcriptional machinery at active gene loci.
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Affiliation(s)
- Lidice González
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC, H3C 3J7, Canada
| | - Daniel Kolbin
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Christian Trahan
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - Célia Jeronimo
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
| | - François Robert
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, H3A 1A3, Canada
- Département de Médecine, Faculté de Médecine, Université de Montréal, 2900 Boul. Édouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - Marlene Oeffinger
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC, H3C 3J7, Canada
- Institut de recherches cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Faculty of Medicine, Division of Experimental Medicine, McGill University, Montréal, QC, H3A 1A3, Canada
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Stephen W Michnick
- Département de Biochimie, Université de Montréal, C.P. 6128, Succursale centre-ville, Montréal, QC, H3C 3J7, Canada.
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7
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Fujita Y, Pather SR, Ming GL, Song H. 3D spatial genome organization in the nervous system: From development and plasticity to disease. Neuron 2022; 110:2902-2915. [PMID: 35777365 PMCID: PMC9509413 DOI: 10.1016/j.neuron.2022.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/15/2022] [Accepted: 06/03/2022] [Indexed: 01/03/2023]
Abstract
Chromatin is organized into multiscale three-dimensional structures, including chromosome territories, A/B compartments, topologically associating domains, and chromatin loops. This hierarchically organized genomic architecture regulates gene transcription, which, in turn, is essential for various biological processes during brain development and adult plasticity. Here, we review different aspects of spatial genome organization and their functions in regulating gene expression in the nervous system, as well as their dysregulation in brain disorders. We also highlight new technologies to probe and manipulate chromatin architecture and discuss how investigating spatial genome organization can lead to a better understanding of the nervous system and associated disorders.
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Affiliation(s)
- Yuki Fujita
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo City, Shimane 693-8501, Japan.
| | - Sarshan R Pather
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Guo-Li Ming
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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8
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Schirmer EC. Nuclear organization and dynamics: The final Frontier for understanding genome regulation. Front Cell Dev Biol 2022; 10:951875. [PMID: 35923850 PMCID: PMC9340541 DOI: 10.3389/fcell.2022.951875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/27/2022] [Indexed: 11/20/2022] Open
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9
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Nakayama K, Shachar S, Finn EH, Sato H, Hirakawa A, Misteli T. Large-scale mapping of positional changes of hypoxia-responsive genes upon activation. Mol Biol Cell 2022; 33:ar72. [PMID: 35476603 PMCID: PMC9635277 DOI: 10.1091/mbc.e21-11-0593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Chromosome structure and nuclear organization are important factors in the regulation of gene expression. Transcription of a gene is influenced by local and global chromosome features such as chromatin condensation status. The relationship between the 3D position of a gene in the nucleus and its activity is less clear. Here we used high-throughput imaging to perform a large-scale analysis of the spatial location of nearly 100 hypoxia-responsive genes to determine whether their location and activity state are correlated. Radial distance analysis demonstrated that the majority of Hypoxia-Inducible Factor (HIF)- and CREB-dependent hypoxia-responsive genes are located in the intermediate region of the nucleus, and some of them changed their radial position in hypoxia. Analysis of the relative distances among a subset of HIF target genes revealed that some gene pairs altered their relative location to each other on hypoxic treatment, suggesting higher-order chromatin rearrangements. While these changes in location occurred in response to hypoxic activation of the target genes, they did not correlate with the extent of their activation. These results suggest that induction of the hypoxia-responsive gene expression program is accompanied by spatial alterations of the genome, but that radial and relative gene positions are not directly related to gene activity.
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Affiliation(s)
- Koh Nakayama
- Oxygen Biology Laboratory, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo 113-8510, Japan.,Department of Pharmacology, School of Medicine, Asahikawa Medical University, Asahikawa, Hokkaido 078-8510, Japan.,Cell Biology of Genomes Group, Center for Cancer Research, National Cancer Institute NIH, Bethesda, 20892
| | - Sigal Shachar
- Cell Biology of Genomes Group, Center for Cancer Research, National Cancer Institute NIH, Bethesda, 20892
| | - Elizabeth H Finn
- Cell Biology of Genomes Group, Center for Cancer Research, National Cancer Institute NIH, Bethesda, 20892
| | - Hiroyuki Sato
- Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo 113-8510, Japan
| | - Akihiro Hirakawa
- Department of Clinical Biostatistics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Bunkyo-ku, Tokyo 113-8510, Japan
| | - Tom Misteli
- Cell Biology of Genomes Group, Center for Cancer Research, National Cancer Institute NIH, Bethesda, 20892
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10
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Ito K, Takizawa T. Nuclear Architecture in the Nervous System. Results Probl Cell Differ 2022; 70:419-442. [PMID: 36348117 DOI: 10.1007/978-3-031-06573-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Neurons and glial cells in the nervous system exhibit different gene expression programs for neural development and function. These programs are controlled by the epigenetic regulatory layers in the nucleus. The nucleus is a well-organized subcellular organelle that includes chromatin, the nuclear lamina, and nuclear bodies. These subnuclear components operate together as epigenetic regulators of neural development and function and are collectively called the nuclear architecture. In the nervous system, dynamic rearrangement of the nuclear architecture has been observed in each cell type, especially in neurons, allowing for their specialized functions, including learning and memory formation. Although the importance of nuclear architecture has been debated for decades, the paradigm has been changing rapidly, owing to the development of new technologies. Here, we reviewed the latest studies on nuclear geometry, nuclear bodies, and heterochromatin compartments, as well as summarized recent novel insights regarding radial positioning, chromatin condensation, and chromatin interaction between genes and cis-regulatory elements.
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Affiliation(s)
- Kenji Ito
- Institute for Regenerative Medicine and Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Smilow Center for Translational Research, Philadelphia, Pennsylvania, USA
| | - Takumi Takizawa
- Department of Pediatrics, Gunma University Graduate School of Medicine, Maebashi, Japan.
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11
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Noguchi A, Ito K, Uosaki Y, Ideta-Otsuka M, Igarashi K, Nakashima H, Kakizaki T, Kaneda R, Uosaki H, Yanagawa Y, Nakashima K, Arakawa H, Takizawa T. Decreased Lamin B1 Levels Affect Gene Positioning and Expression in Postmitotic Neurons. Neurosci Res 2021; 173:22-33. [PMID: 34058264 DOI: 10.1016/j.neures.2021.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 01/01/2023]
Abstract
Gene expression programs and concomitant chromatin regulation change dramatically during the maturation of postmitotic neurons. Subnuclear positioning of gene loci is relevant to transcriptional regulation. However, little is known about subnuclear genome positioning in neuronal maturation. Using cultured murine hippocampal neurons, we found genomic locus 14qD2 to be enriched with genes that are upregulated during neuronal maturation. Reportedly, the locus is homologous to human 8p21.3, which has been extensively studied in neuropsychiatry and neurodegenerative diseases. Mapping of the 14qD2 locus in the nucleus revealed that it was relocated from the nuclear periphery to the interior. Moreover, we found a concomitant decrease in lamin B1 expression. Overexpression of lamin B1 in neurons using a lentiviral vector prevented the relocation of the 14qD2 locus and repressed the transcription of the Egr3 gene on this locus. Taken together, our results suggest that reduced lamin B1 expression during the maturation of neurons is important for appropriate subnuclear positioning of the genome and transcriptional programs.
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Affiliation(s)
- Azumi Noguchi
- Gunma University Graduate School of Medicine, Department of Pediatrics, Maebashi, 371-8511, Japan
| | - Kenji Ito
- Gunma University Graduate School of Medicine, Department of Pediatrics, Maebashi, 371-8511, Japan; University of Pennsylvania, Perelman School of Medicine, Institute for Regenerative Medicine, Department of Cell and Developmental Biology, Philadelphia, PA, 19104-5157, USA
| | - Yuichi Uosaki
- Gunma University Graduate School of Medicine, Department of Pediatrics, Maebashi, 371-8511, Japan
| | - Maky Ideta-Otsuka
- Hoshi University School of Pharmacy Pharmaceutical Science, Life Science Tokyo Advanced Research Center (L-StaR), Tokyo, 142 8501, Japan
| | - Katsuhide Igarashi
- Hoshi University School of Pharmacy Pharmaceutical Science, Life Science Tokyo Advanced Research Center (L-StaR), Tokyo, 142 8501, Japan
| | - Hideyuki Nakashima
- Kyushu University, Department of Stem Cell Biology and Medicine Graduate School of Medical Sciences, Fukuoka, 812 8582, Japan
| | - Toshikazu Kakizaki
- Gunma University Graduate School of Medicine, Department of Genetic and Behavioral Neuroscience, Maebashi, 371 8511, Japan
| | - Ruri Kaneda
- Jichi Medical University, Support Center for Clinical Investigation, Shimotsuke, 329 0498, Japan
| | - Hideki Uosaki
- Jichi Medical University, Division of Regenerative Medicine, Center for Molecular Medicine, Shimotsuke, 329 0498, Japan; Jichi Medical University, Center for Development of Advanced Medical Technology, Shimotsuke, 329 0498, Japan
| | - Yuchio Yanagawa
- Gunma University Graduate School of Medicine, Department of Genetic and Behavioral Neuroscience, Maebashi, 371 8511, Japan
| | - Kinichi Nakashima
- Kyushu University, Department of Stem Cell Biology and Medicine Graduate School of Medical Sciences, Fukuoka, 812 8582, Japan
| | - Hirokazu Arakawa
- Gunma University Graduate School of Medicine, Department of Pediatrics, Maebashi, 371-8511, Japan
| | - Takumi Takizawa
- Gunma University Graduate School of Medicine, Department of Pediatrics, Maebashi, 371-8511, Japan.
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12
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Abstract
Mammalian genomes have distinct levels of spatial organization and structure that have been hypothesized to play important roles in transcription regulation. Although much has been learned about these architectural features with ensemble techniques, single-cell studies are showing a new universal trend: Genomes are stochastic and dynamic at every level of organization. Stochastic gene expression, on the other hand, has been studied for years. In this review, we probe whether there is a causative link between the two phenomena. We specifically discuss the functionality of chromatin state, topologically associating domains (TADs), and enhancer biology in light of their stochastic nature and their specific roles in stochastic gene expression. We highlight persistent fundamental questions in this area of research.
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Affiliation(s)
- Christopher H Bohrer
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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13
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Lucas T, Hafer TL, Zhang HG, Molotkova N, Kohwi M. Discrete cis-acting element regulates developmentally timed gene-lamina relocation and neural progenitor competence in vivo. Dev Cell 2021; 56:2649-2663.e6. [PMID: 34529940 PMCID: PMC8629127 DOI: 10.1016/j.devcel.2021.08.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/24/2021] [Accepted: 08/20/2021] [Indexed: 01/21/2023]
Abstract
The nuclear lamina is typically associated with transcriptional silencing, and peripheral relocation of genes highly correlates with repression. However, the DNA sequences and proteins regulating gene-lamina interactions are largely unknown. Exploiting the developmentally timed hunchback gene movement to the lamina in Drosophila neuroblasts, we identified a 250 bp intronic element (IE) both necessary and sufficient for relocation. The IE can target a reporter transgene to the lamina and silence it. Endogenously, however, hunchback is already repressed prior to relocation. Instead, IE-mediated relocation confers a heritably silenced gene state refractory to activation in descendent neurons, which terminates neuroblast competence to specify early-born identity. Surprisingly, we found that the Polycomb group chromatin factors bind the IE and are required for lamina relocation, revealing a nuclear architectural role distinct from their well-known function in transcriptional repression. Together, our results uncover in vivo mechanisms underlying neuroblast competence and lamina association in heritable gene silencing. In Drosophila neuroblasts, relocation of the hunchback gene locus to the nuclear lamina confers heritable silencing in daughter neurons. Lucas et al. identify a genomic element necessary and sufficient for hunchback gene movement in vivo. Polycomb proteins target this element for lamina relocation, thereby regulating competence, but not hunchback expression.
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Affiliation(s)
- Tanguy Lucas
- Department of Neuroscience, Mortimer B. Zuckerman Institute Mind Brain Behavior, Columbia University, New York, NY 10027, USA
| | - Terry L Hafer
- Department of Neuroscience, Mortimer B. Zuckerman Institute Mind Brain Behavior, Columbia University, New York, NY 10027, USA
| | - Harrison G Zhang
- Department of Neuroscience, Mortimer B. Zuckerman Institute Mind Brain Behavior, Columbia University, New York, NY 10027, USA
| | - Natalia Molotkova
- Department of Neuroscience, Mortimer B. Zuckerman Institute Mind Brain Behavior, Columbia University, New York, NY 10027, USA
| | - Minoree Kohwi
- Department of Neuroscience, Mortimer B. Zuckerman Institute Mind Brain Behavior, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
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14
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Abstract
Cancers and developmental disorders are associated with alterations in the 3D genome architecture in space and time (the fourth dimension). Mammalian 3D genome organization is complex and dynamic and plays an essential role in regulating gene expression and cellular function. To study the causal relationship between genome function and its spatio-temporal organization in the nucleus, new technologies for engineering and manipulating the 3D organization of the genome have been developed. In particular, CRISPR-Cas technologies allow programmable manipulation at specific genomic loci, enabling unparalleled opportunities in this emerging field of 3D genome engineering. We review advances in mammalian 3D genome engineering with a focus on recent manipulative technologies using CRISPR-Cas and related technologies.
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15
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Gatticchi L, de Las Heras JI, Sivakumar A, Zuleger N, Roberti R, Schirmer EC. Tm7sf2 Disruption Alters Radial Gene Positioning in Mouse Liver Leading to Metabolic Defects and Diabetes Characteristics. Front Cell Dev Biol 2020; 8:592573. [PMID: 33330474 PMCID: PMC7719783 DOI: 10.3389/fcell.2020.592573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 10/26/2020] [Indexed: 01/23/2023] Open
Abstract
Tissue-specific patterns of radial genome organization contribute to genome regulation and can be established by nuclear envelope proteins. Studies in this area often use cancer cell lines, and it is unclear how well such systems recapitulate genome organization of primary cells or animal tissues; so, we sought to investigate radial genome organization in primary liver tissue hepatocytes. Here, we have used a NET47/Tm7sf2–/– liver model to show that manipulating one of these nuclear membrane proteins is sufficient to alter tissue-specific gene positioning and expression. Dam-LaminB1 global profiling in primary liver cells shows that nearly all the genes under such positional regulation are related to/important for liver function. Interestingly, Tm7sf2 is a paralog of the HP1-binding nuclear membrane protein LBR that, like Tm7sf2, also has an enzymatic function in sterol reduction. Fmo3 gene/locus radial mislocalization could be rescued with human wild-type, but not TM7SF2 mutants lacking the sterol reductase function. One central pathway affected is the cholesterol synthesis pathway. Within this pathway, both Cyp51 and Msmo1 are under Tm7sf2 positional and expression regulation. Other consequences of the loss of Tm7sf2 included weight gain, insulin sensitivity, and reduced levels of active Akt kinase indicating additional pathways under its regulation, several of which are highlighted by mispositioning genes. This study emphasizes the importance for tissue-specific radial genome organization in tissue function and the value of studying genome organization in animal tissues and primary cells over cell lines.
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Affiliation(s)
- Leonardo Gatticchi
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Jose I de Las Heras
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Aishwarya Sivakumar
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Nikolaj Zuleger
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Rita Roberti
- Department of Experimental Medicine, University of Perugia, Perugia, Italy
| | - Eric C Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
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16
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Madl CM, LeSavage BL, Khariton M, Heilshorn SC. Neural Progenitor Cells Alter Chromatin Organization and Neurotrophin Expression in Response to 3D Matrix Degradability. Adv Healthc Mater 2020; 9:e2000754. [PMID: 32743903 DOI: 10.1002/adhm.202000754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/14/2020] [Indexed: 11/09/2022]
Abstract
Neural progenitor cells (NPCs) are promising therapeutic candidates for nervous system regeneration. Significant efforts focus on developing hydrogel-based approaches to facilitate the clinical translation of NPCs, from scalable platforms for stem cell production to injectable carriers for cell transplantation. However, fundamental questions surrounding NPC-hydrogel interactions remain unanswered. While matrix degradability is known to regulate the stemness and differentiation capacity of NPCs, how degradability impacts NPC epigenetic regulation and secretory phenotype remains unknown. To address this question, NPCs encapsulated in recombinant protein hydrogels with tunable degradability are assayed for changes in chromatin organization and neurotrophin expression. In high degradability gels, NPCs maintain expression of stem cell factors, proliferate, and have large nuclei with elevated levels of the stemness-associated activating histone mark H3K4me3. In contrast, NPCs in low degradability gels exhibit more compact, rounded nuclei with peripherally localized heterochromatin, are non-proliferative yet non-senescent, and maintain expression of neurotrophic factors with potential therapeutic relevance. This work suggests that tuning matrix degradability may be useful to direct NPCs toward either a more-proliferative, stem-like phenotype for cell replacement therapies, or a more quiescent-like, pro-secretory phenotype for soluble factor-mediated therapies.
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Affiliation(s)
- Christopher M. Madl
- Department of Bioengineering Stanford University Stanford CA 94305 USA
- Baxter Laboratory for Stem Cell Biology Department of Microbiology & Immunology Stanford University Stanford CA 94305 USA
| | - Bauer L. LeSavage
- Department of Bioengineering Stanford University Stanford CA 94305 USA
| | | | - Sarah C. Heilshorn
- Department of Materials Science & Engineering Stanford University 476 Lomita Mall, McCullough Room 246 Stanford CA 94305 USA
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17
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Canat A, Veillet A, Bonnet A, Therizols P. Genome anchoring to nuclear landmarks drives functional compartmentalization of the nuclear space. Brief Funct Genomics 2020; 19:101-110. [DOI: 10.1093/bfgp/elz034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 11/04/2019] [Accepted: 11/05/2019] [Indexed: 01/18/2023] Open
Abstract
Abstract
The spatial organization of the genome contributes to essential functions such as transcription and chromosome integrity maintenance. The principles governing nuclear compartmentalization have been the focus of considerable research over the last decade. In these studies, the genome–nuclear structure interactions emerged as a main driver of this particular 3D genome organization. In this review, we describe the interactions between the genome and four major landmarks of the nucleus: the nuclear lamina, the nuclear pores, the pericentromeric heterochromatin and the nucleolus. We present the recent studies that identify sequences bound to these different locations and address the tethering mechanisms. We give an overview of the relevance of this organization in development and disease. Finally, we discuss the dynamic aspects and self-organizing properties that allow this complex architecture to be inherited.
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Affiliation(s)
- Antoine Canat
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Adeline Veillet
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Amandine Bonnet
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Pierre Therizols
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
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18
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Cardozo Gizzi AM, Cattoni DI, Nollmann M. TADs or no TADS: Lessons From Single-cell Imaging of Chromosome Architecture. J Mol Biol 2020; 432:682-693. [PMID: 31904354 DOI: 10.1016/j.jmb.2019.12.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/12/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022]
Abstract
Eukaryotic genomes are folded in a hierarchical organization that reflects and possibly regulates their function. Genomewide studies revealed a new level of organization at the kilobase-to-megabase scale termed "topological associating domains" (TADs). TADs are characterized as stable units of chromosome organization that restrict the action of regulatory sequences within one "functional unit." Consequently, TADs are expected to appear as physical entities in most cells. Very recent single-cell studies have shown a notable variability in genome architecture at this scale, raising concerns about this model. Furthermore, the direct and simultaneous observation of genome architecture and transcriptional output showed the lack of stable interactions between regulatory sequences in transcribing cells. These findings are consistent with a large body of evidence suggesting that genome organization is highly heterogeneous at different scales. In this review, we discuss the main strategies employed to image chromatin organization, present the latest state-of-the-art developments, and propose an interpretation reconciling population-based findings with direct single-cell chromatin organization observations. All in all, we propose that TADs are made of multiple, low-frequency, low-affinity interactions that increase the probability, but are not deterministic, of regulatory interactions.
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Affiliation(s)
- Andrés M Cardozo Gizzi
- CIQUIBIC (CONICET), Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000, Córdoba, Argentina
| | - Diego I Cattoni
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 rue de Navacelles, 34090, Montpellier, France
| | - Marcelo Nollmann
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université de Montpellier, 60 rue de Navacelles, 34090, Montpellier, France.
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19
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Developmental conservation of microRNA gene localization at the nuclear periphery. PLoS One 2019; 14:e0223759. [PMID: 31682635 PMCID: PMC6827902 DOI: 10.1371/journal.pone.0223759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/27/2019] [Indexed: 12/21/2022] Open
Abstract
microRNAs are of vital importance for the regulation of the adaptive and innate immune responses, modulating gene expression at the post transcriptional level. Although there is cumulative information regarding the steady state mature microRNA levels and their respective targets, little is known about the effect of the three-dimensional chromatin architecture on the transcriptional regulation of microRNA gene loci. Here, we sought to investigate the effect of subnuclear localization on the transcriptional activation of eight murine microRNA loci in the immune system. Our results show that microRNA genes display a preferential monoallelic gene expression profile accompanied with perinuclear localization irrespectively of their transcription status or differentiation state. The expression profile and perinuclear localization are developmentally conserved while microRNA gene loci localization outside constitutive lamin associated domains is cross-species conserved. Our findings provide support for an active nuclear periphery and its role in chromatin organization of the non-coding genome.
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20
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Karnay A, Karisetty BC, Beaver M, Elefant F. Hippocampal stimulation promotes intracellular Tip60 dynamics with concomitant genome reorganization and synaptic gene activation. Mol Cell Neurosci 2019; 101:103412. [PMID: 31682915 DOI: 10.1016/j.mcn.2019.103412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/07/2019] [Accepted: 09/17/2019] [Indexed: 11/17/2022] Open
Abstract
Genomic reorganizations mediating the engagement of target genes to transcription factories (TFs), characterized as specialized nuclear subcompartments enriched in hyperphosphorylated RNA polymerase II (RNAPII) and transcriptional regulators, act as an important layer of control in coordinating efficient gene transcription. However, their presence in hippocampal neurons and potential role in activity-dependent coregulation of genes within the brain remains unclear. Here, we investigate whether the well-characterized role for the histone acetyltransferase (HAT) Tip60 in mediating epigenetic control of inducible neuroplasticity genes involves TF associated chromatin reorganization in the hippocampus. We show that Tip60 shuttles into the nucleus following extracellular stimulation of rat hippocampal neurons with concomitant enhancement of Tip60 binding and activation of specific synaptic plasticity genes. Multicolor three-dimensional (3D) DNA fluorescent in situ hybridization (DNA-FISH) reveals that hippocampal stimulation mobilizes these same synaptic plasticity genes and Tip60 to RNAPII-rich TFs. Our data support a model by which external hippocampal stimulation promotes intracellular Tip60 HAT dynamics with concomitant TF associated genome reorganization to initiate Tip60mediated synaptic gene activation.
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Affiliation(s)
- Ashley Karnay
- Department of Biology, Drexel University, Philadelphia, PA, USA; Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | | | - Mariah Beaver
- Department of Biology, Drexel University, Philadelphia, PA, USA
| | - Felice Elefant
- Department of Biology, Drexel University, Philadelphia, PA, USA.
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21
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Meaburn KJ, Misteli T. Assessment of the Utility of Gene Positioning Biomarkers in the Stratification of Prostate Cancers. Front Genet 2019; 10:1029. [PMID: 31681438 PMCID: PMC6812139 DOI: 10.3389/fgene.2019.01029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/25/2019] [Indexed: 12/24/2022] Open
Abstract
There is a pressing need for additional clinical biomarkers to predict the aggressiveness of individual cancers. Here, we examine the potential usefulness of spatial genome organization as a prognostic tool for prostate cancer. Using fluorescence in situ hybridization on formalin-fixed, paraffin embedded human prostate tissue specimens, we compared the nuclear positions of four genes between clinically relevant subgroups of prostate tissues. We find that directional repositioning of SP100 and TGFB3 gene loci stratifies prostate cancers of differing Gleason scores. A more peripheral position of SP100 and TGFB3 in the nucleus, compared to benign tissues, is associated with low Gleason score cancers, whereas more internal positioning correlates with higher Gleason scores. Conversely, LMNA is more internally positioned in many non-metastatic prostate cancers, while its position is indistinguishable from benign tissue in metastatic cancer. The false positive rates were relatively low, whereas, the false negative rates of single or combinations of genes were high, limiting the clinical utility of this assay in its current form. Nevertheless, our findings of subtype-specific gene positioning patterns in prostate cancer provides proof-of-concept for the potential usefulness of spatial gene positioning for prognostic applications, and encourage further exploration of spatial gene positioning patterns to identify novel clinically relevant molecular biomarkers, which may aid treatment decisions for cancer patients.
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Affiliation(s)
- Karen J Meaburn
- Cell Biology of Genomes Group, National Cancer Institute, NIH, Bethesda, MD, United States
| | - Tom Misteli
- Cell Biology of Genomes Group, National Cancer Institute, NIH, Bethesda, MD, United States
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22
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Ruszczycki B, Pels KK, Walczak A, Zamłyńska K, Such M, Szczepankiewicz AA, Hall MH, Magalska A, Magnowska M, Wolny A, Bokota G, Basu S, Pal A, Plewczynski D, Wilczyński GM. Three-Dimensional Segmentation and Reconstruction of Neuronal Nuclei in Confocal Microscopic Images. Front Neuroanat 2019; 13:81. [PMID: 31481881 PMCID: PMC6710455 DOI: 10.3389/fnana.2019.00081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/31/2019] [Indexed: 12/31/2022] Open
Abstract
The detailed architectural examination of the neuronal nuclei in any brain region, using confocal microscopy, requires quantification of fluorescent signals in three-dimensional stacks of confocal images. An essential prerequisite to any quantification is the segmentation of the nuclei which are typically tightly packed in the tissue, the extreme being the hippocampal dentate gyrus (DG), in which nuclei frequently appear to overlap due to limitations in microscope resolution. Segmentation in DG is a challenging task due to the presence of a significant amount of image artifacts and densely packed nuclei. Accordingly, we established an algorithm based on continuous boundary tracing criterion aiming to reconstruct the nucleus surface and to separate the adjacent nuclei. The presented algorithm neither uses a pre-built nucleus model, nor performs image thresholding, which makes it robust against variations in image intensity and poor contrast. Further, the reconstructed surface is used to study morphology and spatial arrangement of the nuclear interior. The presented method is generally dedicated to segmentation of crowded, overlapping objects in 3D space. In particular, it allows us to study quantitatively the architecture of the neuronal nucleus using confocal-microscopic approach.
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Affiliation(s)
- Błażej Ruszczycki
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | | | - Agnieszka Walczak
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznan, Poland
| | | | - Michał Such
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.,Center of New Technologies, University of Warsaw, Warsaw, Poland
| | | | - Małgorzata Hanna Hall
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland.,Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Adriana Magalska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Marta Magnowska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Artur Wolny
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Grzegorz Bokota
- Center of New Technologies, University of Warsaw, Warsaw, Poland
| | - Subhadip Basu
- Department of Computer Science and Engineering, Jadavpur University, Kolkata, India
| | - Ayan Pal
- Department of Computer Science and Engineering, Jadavpur University, Kolkata, India
| | - Dariusz Plewczynski
- Center of New Technologies, University of Warsaw, Warsaw, Poland.,Faculty of Mathematics and Information Science, Warsaw University of Technology, Warsaw, Poland
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23
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Dileep V, Wilson KA, Marchal C, Lyu X, Zhao PA, Li B, Poulet A, Bartlett DA, Rivera-Mulia JC, Qin ZS, Robins AJ, Schulz TC, Kulik MJ, McCord RP, Dekker J, Dalton S, Corces VG, Gilbert DM. Rapid Irreversible Transcriptional Reprogramming in Human Stem Cells Accompanied by Discordance between Replication Timing and Chromatin Compartment. Stem Cell Reports 2019; 13:193-206. [PMID: 31231024 PMCID: PMC6627004 DOI: 10.1016/j.stemcr.2019.05.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/20/2019] [Accepted: 05/20/2019] [Indexed: 02/02/2023] Open
Abstract
The temporal order of DNA replication is regulated during development and is highly correlated with gene expression, histone modifications and 3D genome architecture. We tracked changes in replication timing, gene expression, and chromatin conformation capture (Hi-C) A/B compartments over the first two cell cycles during differentiation of human embryonic stem cells to definitive endoderm. Remarkably, transcriptional programs were irreversibly reprogrammed within the first cell cycle and were largely but not universally coordinated with replication timing changes. Moreover, changes in A/B compartment and several histone modifications that normally correlate strongly with replication timing showed weak correlation during the early cell cycles of differentiation but showed increased alignment in later differentiation stages and in terminally differentiated cell lines. Thus, epigenetic cell fate transitions during early differentiation can occur despite dynamic and discordant changes in otherwise highly correlated genomic properties.
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Affiliation(s)
- Vishnu Dileep
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Korey A Wilson
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Claire Marchal
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Xiaowen Lyu
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Peiyao A Zhao
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Ben Li
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
| | - Axel Poulet
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
| | - Daniel A Bartlett
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Juan Carlos Rivera-Mulia
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA
| | - Zhaohui S Qin
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA 30322, USA
| | | | | | - Michael J Kulik
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Rachel Patton McCord
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Job Dekker
- Program in Systems Biology, Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Stephen Dalton
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Victor G Corces
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - David M Gilbert
- Department of Biological Science, Florida State University, 319 Stadium Drive, Tallahassee, FL 32306, USA.
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24
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Brookes E, Riccio A. Location, location, location: nuclear structure regulates gene expression in neurons. Curr Opin Neurobiol 2019; 59:16-25. [PMID: 31005709 DOI: 10.1016/j.conb.2019.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/27/2019] [Accepted: 03/18/2019] [Indexed: 12/27/2022]
Abstract
Genome architecture plays a critical role in regulating the expression of genes that are essential for nervous system development. During neuronal differentiation, spatially and temporally regulated transcription allows neuronal migration, the growth of dendrites and axons, and at later stages, synaptic formation and the establishment of neuronal circuitry. Genome topology and relocation of gene loci within the nucleus are now regarded as key factors that contribute to transcriptional regulation. Here, we review recent work supporting the hypothesis that the dynamic organization of chromatin within the nucleus impacts gene activation in response to extrinsic signalling and during neuronal differentiation. The consequences of disruption of the genome architecture on neuronal health will be also discussed.
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Affiliation(s)
- Emily Brookes
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Antonella Riccio
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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25
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Kang S, Chovatiya G, Tumbar T. Epigenetic control in skin development, homeostasis and injury repair. Exp Dermatol 2019; 28:453-463. [PMID: 30624812 PMCID: PMC6488370 DOI: 10.1111/exd.13872] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/11/2018] [Accepted: 01/05/2019] [Indexed: 12/14/2022]
Abstract
Cell-type- and cell-state-specific patterns of covalent modifications on DNA and histone tails form global epigenetic profiles that enable spatiotemporal regulation of gene expression. These epigenetic profiles arise from coordinated activities of transcription factors and epigenetic modifiers, which result in cell-type-specific outputs in response to dynamic environmental conditions and signalling pathways. Recent mouse genetic and functional studies have highlighted the physiological significance of global DNA and histone epigenetic modifications in skin. Importantly, specific epigenetic profiles are emerging for adult skin stem cells that are associated with their cell fate plasticity and proper activity in tissue regeneration. We can now begin to draw a more comprehensive picture of how epigenetic modifiers orchestrate their cell-intrinsic role with microenvironmental cues for proper skin development, homeostasis and wound repair. The field is ripe to begin to implement these findings from the laboratory into skin therapies.
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Affiliation(s)
- Sangjo Kang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Gopal Chovatiya
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
| | - Tudorita Tumbar
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York
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26
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Nuclear lamina integrity is required for proper spatial organization of chromatin in Drosophila. Nat Commun 2019; 10:1176. [PMID: 30862957 PMCID: PMC6414625 DOI: 10.1038/s41467-019-09185-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 02/21/2019] [Indexed: 11/25/2022] Open
Abstract
How the nuclear lamina (NL) impacts on global chromatin architecture is poorly understood. Here, we show that NL disruption in Drosophila S2 cells leads to chromatin compaction and repositioning from the nuclear envelope. This increases the chromatin density in a fraction of topologically-associating domains (TADs) enriched in active chromatin and enhances interactions between active and inactive chromatin. Importantly, upon NL disruption the NL-associated TADs become more acetylated at histone H3 and less compact, while background transcription is derepressed. Two-colour FISH confirms that a TAD becomes less compact following its release from the NL. Finally, polymer simulations show that chromatin binding to the NL can per se compact attached TADs. Collectively, our findings demonstrate a dual function of the NL in shaping the 3D genome. Attachment of TADs to the NL makes them more condensed but decreases the overall chromatin density in the nucleus by stretching interphase chromosomes. The role of the nuclear lamina (NL) in chromatin architecture is still poorly understood. Here, the authors provide evidence that disruption of the NL in Drosophila cells leads to overall chromatin compaction and repositioning from the nuclear envelope, whereas lamina-associated regions become less compacted and transcription within them is increased.
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27
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Stachecka J, Nowacka-Woszuk J, Kolodziejski PA, Szczerbal I. The importance of the nuclear positioning of the PPARG gene for its expression during porcine in vitro adipogenesis. Chromosome Res 2019; 27:271-284. [PMID: 30656515 PMCID: PMC6733831 DOI: 10.1007/s10577-019-09604-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/04/2019] [Accepted: 01/09/2019] [Indexed: 01/27/2023]
Abstract
Proper expression of the PPARG gene, which encodes a key transcription factor of adipogenesis, is indispensable in the formation of mature adipocytes. The positioning of a gene within the nuclear space has been implicated in gene regulation. We here report on the significance of the PPARG gene’s nuclear positioning for its activity during in vitro adipogenesis in the pig. We used an established system of differentiation of mesenchymal stem cells derived from bone marrow and adipose tissue into adipocytes. The differentiation process was carried out for 7 days, and the cells were examined using the 3D DNA/immuno-FISH and RNA/DNA-FISH approaches. PPARG transcript level was measured using real-time PCR, and PPARγ activity was detected with colorimetric assay. Changes in the nuclear location of the PPARG gene were observed when we compared undifferentiated mesenchymal stem cells with mature adipocytes. The gene moved from the nuclear periphery to the nuclear center as its transcriptional activity increased. The RNA/DNA-FISH approach shows that differences in primary transcript production correlated with the allele’s nuclear positioning. Transcriptionally active alleles preferentially occupy the central part of the nucleus, while inactive alleles are found on the nuclear periphery. We also show that transcription of PPARG begins with one allele, but that both alleles are active in later stages of differentiation. Our results provide evidence that functionally distinct alleles of the PPARG gene are positioned in different parts of the cell nucleus. This confirms the importance of nuclear architecture to the regulation of PPARG gene transcription, and thus to the fate of the adipose cell.
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Affiliation(s)
- Joanna Stachecka
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland
| | - Joanna Nowacka-Woszuk
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland
| | - Pawel A Kolodziejski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska 35, 60-637, Poznan, Poland
| | - Izabela Szczerbal
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Wolynska 33, 60-637, Poznan, Poland.
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28
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Wang H, Xu X, Nguyen CM, Liu Y, Gao Y, Lin X, Daley T, Kipniss NH, La Russa M, Qi LS. CRISPR-Mediated Programmable 3D Genome Positioning and Nuclear Organization. Cell 2018; 175:1405-1417.e14. [PMID: 30318144 PMCID: PMC6239909 DOI: 10.1016/j.cell.2018.09.013] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/09/2018] [Accepted: 09/10/2018] [Indexed: 12/20/2022]
Abstract
Programmable control of spatial genome organization is a powerful approach for studying how nuclear structure affects gene regulation and cellular function. Here, we develop a versatile CRISPR-genome organization (CRISPR-GO) system that can efficiently control the spatial positioning of genomic loci relative to specific nuclear compartments, including the nuclear periphery, Cajal bodies, and promyelocytic leukemia (PML) bodies. CRISPR-GO is chemically inducible and reversible, enabling interrogation of real-time dynamics of chromatin interactions with nuclear compartments in living cells. Inducible repositioning of genomic loci to the nuclear periphery allows for dissection of mitosis-dependent and -independent relocalization events and also for interrogation of the relationship between gene position and gene expression. CRISPR-GO mediates rapid de novo formation of Cajal bodies at desired chromatin loci and causes significant repression of endogenous gene expression over long distances (30-600 kb). The CRISPR-GO system offers a programmable platform to investigate large-scale spatial genome organization and function.
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Affiliation(s)
- Haifeng Wang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Xiaoshu Xu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Cindy M Nguyen
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Yanxia Liu
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Yuchen Gao
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Cancer Biology Program, Stanford University, Stanford, CA 94305, USA
| | - Xueqiu Lin
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Timothy Daley
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Statistics, Stanford University, Stanford, CA 94305, USA
| | - Nathan H Kipniss
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Marie La Russa
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Stanford ChEM-H, Stanford University, Stanford, CA 94305, USA.
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29
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Ito K, Takizawa T. Nuclear Architecture in the Nervous System: Development, Function, and Neurodevelopmental Diseases. Front Genet 2018; 9:308. [PMID: 30127803 PMCID: PMC6087739 DOI: 10.3389/fgene.2018.00308] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 07/19/2018] [Indexed: 12/22/2022] Open
Abstract
Decades of study have shown that epigenetic regulation plays an important role in neural development and function. Several layers of epigenetic mechanisms control functions of the eukaryotic cell nucleus, a well-organized subcellular organelle with distinct compartments: chromatin, its related architectural proteins, and nuclear bodies. As these components function together in the epigenetic regulation of cellular development and functions, they are collectively termed nuclear architecture. In the nervous system, dynamic rearrangement of nuclear architecture correlates with alteration of transcription programs. During maturation and upon depolarization, neurons undergo a reorganization of nuclear architecture that alters gene expression programs. As such changes allow for specialized functions, including learning and memory, nuclear architecture is distinct among cell types. Studying nuclear architecture of neurons may uncover cell-division-independent mechanisms of global and local changes to nuclear architecture. We herein review recent research concerning nuclear architecture in the nervous system and will discuss its importance to the development, maturation, function, and diseases of the nervous system.
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Affiliation(s)
- Kenji Ito
- Department of Pediatrics, Graduate School of Medicine, Gunma University, Maebashi, Japan.,Division of Stem Cell Pathology, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Takumi Takizawa
- Department of Pediatrics, Graduate School of Medicine, Gunma University, Maebashi, Japan
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30
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Yoon KJ, Vissers C, Ming GL, Song H. Epigenetics and epitranscriptomics in temporal patterning of cortical neural progenitor competence. J Cell Biol 2018; 217:1901-1914. [PMID: 29666150 PMCID: PMC5987727 DOI: 10.1083/jcb.201802117] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/05/2018] [Accepted: 04/06/2018] [Indexed: 12/12/2022] Open
Abstract
Yoon et al. review epigenetic and epitranscriptomic mechanisms that regulate the lineage specification of neural progenitor cells in the developing brain. During embryonic brain development, neural progenitor/stem cells (NPCs) sequentially give rise to different subtypes of neurons and glia via a highly orchestrated process. To accomplish the ordered generation of distinct progenies, NPCs go through multistep transitions of their developmental competence. The molecular mechanisms driving precise temporal coordination of these transitions remains enigmatic. Epigenetic regulation, including changes in chromatin structures, DNA methylation, and histone modifications, has been extensively investigated in the context of cortical neurogenesis. Recent studies of chemical modifications on RNA, termed epitranscriptomics, have also revealed their critical roles in neural development. In this review, we discuss advances in understanding molecular regulation of the sequential lineage specification of NPCs in the embryonic mammalian brain with a focus on epigenetic and epitranscriptomic mechanisms. In particular, the discovery of lineage-specific gene transcripts undergoing rapid turnover in NPCs suggests that NPC developmental fate competence is determined much earlier, before the final cell division, and is more tightly controlled than previously appreciated. We discuss how multiple regulatory systems work in harmony to coordinate NPC behavior and summarize recent findings in the context of a model of epigenetic and transcriptional prepatterning to explain NPC developmental competence.
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Affiliation(s)
- Ki-Jun Yoon
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
| | - Caroline Vissers
- The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Cell and Developmental Biology, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,Institute for Regenerative Medicine, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA .,The Biochemistry, Cellular and Molecular Biology Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD.,Department of Cell and Developmental Biology, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,Institute for Regenerative Medicine, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA.,The Epigenetics Institute, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA
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31
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Shevelyov YY, Ulianov SV. Role of Nuclear Lamina in Gene Repression and Maintenance of Chromosome Architecture in the Nucleus. BIOCHEMISTRY (MOSCOW) 2018; 83:359-369. [DOI: 10.1134/s0006297918040077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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32
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Zhao PA, Rivera-Mulia JC, Gilbert DM. Replication Domains: Genome Compartmentalization into Functional Replication Units. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1042:229-257. [DOI: 10.1007/978-981-10-6955-0_11] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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33
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Misale MS, Witek Janusek L, Tell D, Mathews HL. Chromatin organization as an indicator of glucocorticoid induced natural killer cell dysfunction. Brain Behav Immun 2018; 67:279-289. [PMID: 28911980 PMCID: PMC5696065 DOI: 10.1016/j.bbi.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 09/01/2017] [Accepted: 09/08/2017] [Indexed: 11/19/2022] Open
Abstract
It is well-established that psychological distress reduces natural killer cell immune function and that this reduction can be due to the stress-induced release of glucocorticoids. Glucocorticoids are known to alter epigenetic marks associated with immune effector loci, and are also known to influence chromatin organization. The purpose of this investigation was to assess the effect of glucocorticoids on natural killer cell chromatin organization and to determine the relationship of chromatin organization to natural killer cell effector function, e.g. interferon gamma production. Interferon gamma production is the prototypic cytokine produced by natural killer cells and is known to modulate both innate and adaptive immunity. Glucocorticoid treatment of human peripheral blood mononuclear cells resulted in a significant reduction in interferon gamma production. Glucocorticoid treatment also resulted in a demonstrable natural killer cell nuclear phenotype. This phenotype was localization of the histone, post-translational epigenetic mark, H3K27me3, to the nuclear periphery. Peripheral nuclear localization of H3K27me3 was directly related to cellular levels of interferon gamma. This nuclear phenotype was determined by direct visual inspection and by use of an automated, high through-put technology, the Amnis ImageStream. This technology combines the per-cell information content provided by standard microscopy with the statistical significance afforded by large sample sizes common to standard flow cytometry. Most importantly, this technology provides for a direct assessment of the localization of signal intensity within individual cells. The results demonstrate glucocorticoids to dysregulate natural killer cell function at least in part through altered H3K27me3 nuclear organization and demonstrate H3K27me3 chromatin organization to be a predictive indicator of glucocorticoid induced immune dysregulation of natural killer cells.
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Affiliation(s)
- Michael S Misale
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Health Science Division, 2160 South First Ave., Maywood, IL 60153, United States
| | - Linda Witek Janusek
- Marcella Niehoff School of Nursing, Department of Health Promotion, Loyola University Chicago, Health Science Division, 2160 South First Ave., Maywood, IL 60153, United States
| | - Dina Tell
- Marcella Niehoff School of Nursing, Department of Health Promotion, Loyola University Chicago, Health Science Division, 2160 South First Ave., Maywood, IL 60153, United States
| | - Herbert L Mathews
- Department of Microbiology and Immunology, Stritch School of Medicine, Loyola University Chicago, Health Science Division, 2160 South First Ave., Maywood, IL 60153, United States.
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34
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Toda T, Hsu JY, Linker SB, Hu L, Schafer ST, Mertens J, Jacinto FV, Hetzer MW, Gage FH. Nup153 Interacts with Sox2 to Enable Bimodal Gene Regulation and Maintenance of Neural Progenitor Cells. Cell Stem Cell 2017; 21:618-634.e7. [PMID: 28919367 DOI: 10.1016/j.stem.2017.08.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 06/17/2017] [Accepted: 08/16/2017] [Indexed: 12/14/2022]
Abstract
Neural progenitor cells (NeuPCs) possess a unique nuclear architecture that changes during differentiation. Nucleoporins are linked with cell-type-specific gene regulation, coupling physical changes in nuclear structure to transcriptional output; but, whether and how they coordinate with key fate-determining transcription factors is unclear. Here we show that the nucleoporin Nup153 interacts with Sox2 in adult NeuPCs, where it is indispensable for their maintenance and controls neuronal differentiation. Genome-wide analyses show that Nup153 and Sox2 bind and co-regulate hundreds of genes. Binding of Nup153 to gene promoters or transcriptional end sites correlates with increased or decreased gene expression, respectively, and inhibiting Nup153 expression alters open chromatin configurations at its target genes, disrupts genomic localization of Sox2, and promotes differentiation in vitro and a gliogenic fate switch in vivo. Together, these findings reveal that nuclear structural proteins may exert bimodal transcriptional effects to control cell fate.
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Affiliation(s)
- Tomohisa Toda
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jonathan Y Hsu
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Sara B Linker
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lauren Hu
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Simon T Schafer
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jerome Mertens
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Filipe V Jacinto
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Martin W Hetzer
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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35
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Cabianca DS, Gasser SM. Spatial segregation of heterochromatin: Uncovering functionality in a multicellular organism. Nucleus 2017; 7:301-7. [PMID: 27187571 DOI: 10.1080/19491034.2016.1187354] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Multiple layers of regulation are required to ensure appropriate patterns of gene expression for accurate cell differentiation. Interphase chromatin is non-randomly distributed within the nucleus, with highly compacted, transcriptionally silent heterochromatin enriched at the nuclear and nucleolar periphery. Whether this spatial organization serves a function in organismal physiology, rather than simply being a byproduct of chromatin metabolism, is a fundamental question. Recent work performed in C. elegans embryos characterized the molecular mechanisms that drive the perinuclear anchoring of heterochromatin. Moreover, for the first time it was shown that heterochromatin sequestration helps to restrict cell differentiation programs, while sustaining commitment to a specified fate. Here, we describe and comment on these findings, placing them in a broader context.
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Affiliation(s)
- Daphne S Cabianca
- a Friedrich Miescher Institute for Biomedical Research , Basel , Switzerland
| | - Susan M Gasser
- a Friedrich Miescher Institute for Biomedical Research , Basel , Switzerland.,b Faculty of Natural Sciences , University of Basel , Basel , Switzerland
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36
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Gigante CM, Dibattista M, Dong FN, Zheng X, Yue S, Young SG, Reisert J, Zheng Y, Zhao H. Lamin B1 is required for mature neuron-specific gene expression during olfactory sensory neuron differentiation. Nat Commun 2017; 8:15098. [PMID: 28425486 PMCID: PMC5411488 DOI: 10.1038/ncomms15098] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 02/28/2017] [Indexed: 01/29/2023] Open
Abstract
B-type lamins are major constituents of the nuclear lamina in all metazoan cells, yet have specific roles in the development of certain cell types. Although they are speculated to regulate gene expression in developmental contexts, a direct link between B-type lamins and developmental gene expression in an in vivo system is currently lacking. Here, we identify lamin B1 as a key regulator of gene expression required for the formation of functional olfactory sensory neurons. By using targeted knockout in olfactory epithelial stem cells in adult mice, we show that lamin B1 deficient neurons exhibit attenuated response to odour stimulation. This deficit can be explained by decreased expression of genes involved in mature neuron function, along with increased expression of genes atypical of the olfactory lineage. These results support that the broadly expressed lamin B1 regulates expression of a subset of genes involved in the differentiation of a specific cell type.
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Affiliation(s)
- Crystal M. Gigante
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218, USA
| | - Michele Dibattista
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104, USA
- Department of Basic Medical Sciences, Neuroscience and Sensory Organs, University of Bari ‘A. Moro', Bari 70121, Italy
| | - Frederick N. Dong
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Xiaobin Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218, USA
| | - Sibiao Yue
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218, USA
| | - Stephen G. Young
- Department of Medicine, Molecular Biology Institute and Department of Human Genetics, University of California, Los Angeles, California 90095, USA
| | - Johannes Reisert
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104, USA
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, Maryland 21218, USA
| | - Haiqing Zhao
- Department of Biology, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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37
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Abstract
The eukaryotic genome is organized in a manner that allows folding of the genetic material in the confined space of the cell nucleus, while at the same time enabling its physiological function. A major principle of spatial genome organization is the non-random position of genomic loci relative to other loci and to nuclear bodies. The mechanisms that determine the spatial position of a locus, and how position affects function, are just beginning to be characterized. Initial results suggest that there are multiple, gene-specific mechanisms and the involvement of a wide range of cellular machineries. In this Commentary, we review recent findings from candidate approaches and unbiased screening methods that provide initial insight into the cellular mechanisms of positioning and their functional consequences. We highlight several specific mechanisms, including tethering of genome regions to the nuclear periphery, passage through S-phase and histone modifications, that contribute to gene positioning in yeast, plants and mammals.
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Affiliation(s)
- Sigal Shachar
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tom Misteli
- National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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38
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Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories. Chromosoma 2017; 126:655-667. [PMID: 28343235 DOI: 10.1007/s00412-017-0629-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/20/2017] [Accepted: 03/07/2017] [Indexed: 10/19/2022]
Abstract
Human chromosomes occupy distinct territories in the interphase nucleus. Such chromosome territories (CTs) are positioned according to gene density. Gene-rich CTs are generally located in the center of the nucleus, while gene-poor CTs are positioned more towards the nuclear periphery. However, the association between gene expression levels and the radial positioning of genes within the CT is still under debate. In the present study, we performed three-dimensional fluorescence in situ hybridization experiments in the colorectal cancer cell lines DLD-1 and LoVo using whole chromosome painting probes for chromosomes 8 and 11 and BAC clones targeting four genes with different expression levels assessed by gene expression arrays and RT-PCR. Our results confirmed that the two over-expressed genes, MYC on chromosome 8 and CCND1 on chromosome 11, are located significantly further away from the center of the CT compared to under-expressed genes on the same chromosomes, i.e., DLC1 and SCN3B. When CCND1 expression was reduced after silencing the major transcription factor of the WNT/β-catenin signaling pathway, TCF7L2, the gene was repositioned and mostly detected in the interior of the CT. Thus, we suggest a non-random distribution in which over-expressed genes are located more towards the periphery of the respective CTs.
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39
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Thanisch K, Song C, Engelkamp D, Koch J, Wang A, Hallberg E, Foisner R, Leonhardt H, Stewart CL, Joffe B, Solovei I. Nuclear envelope localization of LEMD2 is developmentally dynamic and lamin A/C dependent yet insufficient for heterochromatin tethering. Differentiation 2017; 94:58-70. [PMID: 28056360 DOI: 10.1016/j.diff.2016.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 11/28/2022]
Abstract
Peripheral heterochromatin in mammalian nuclei is tethered to the nuclear envelope by at least two mechanisms here referred to as the A- and B-tethers. The A-tether includes lamins A/C and additional unknown components presumably INM protein(s) interacting with both lamins A/C and chromatin. The B-tether includes the inner nuclear membrane (INM) protein Lamin B-receptor, which binds B-type lamins and chromatin. Generally, at least one of the tethers is always present in the nuclear envelope of mammalian cells. Deletion of both causes the loss of peripheral heterochromatin and consequently inversion of the entire nuclear architecture, with this occurring naturally in rod photoreceptors of nocturnal mammals. The tethers are differentially utilized during development, regulate gene expression in opposite manners, and play an important role during cell differentiation. Here we aimed to identify the unknown chromatin binding component(s) of the A-tether. We analyzed 10 mouse tissues by immunostaining with antibodies against 7 INM proteins and found that every cell type has specific, although differentially and developmentally regulated, sets of these proteins. In particular, we found that INM protein LEMD2 is concomitantly expressed with A-type lamins in various cell types but is lacking in inverted nuclei of rod cells. Truncation or deletion of Lmna resulted in the downregulation and mislocalization of LEMD2, suggesting that the two proteins interact and pointing at LEMD2 as a potential chromatin binding mediator of the A-tether. Using nuclei of mouse rods as an experimental model lacking peripheral heterochromatin, we expressed a LEMD2 transgene alone or in combination with lamin C in these cells and observed no restoration of peripheral heterochromatin in either case. We conclude that in contrary to the B-tether, the A-tether has a more intricate composition and consists of multiple components that presumably vary, at differing degrees of redundancy, between cell types and differentiation stages.
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Affiliation(s)
- Katharina Thanisch
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Congdi Song
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Dieter Engelkamp
- Transgenic Service Facility, BTE, Franz-Penzoldt-Centre, Friedrich-Alexander-University of Erlangen-Nürnberg, Erwin-Rommel-Str.3, D-91058 Erlangen, Germany
| | - Jeannette Koch
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Audrey Wang
- Institute of Medical Biology, 8A Biomedical Grove and Dept of Biological Sciences, NUS, 138648, Singapore
| | - Einar Hallberg
- Department of Neurochemistry, Stockholm University, Se-106 91 Stockholm, Sweden
| | - Roland Foisner
- Max F. Perutz Laboratories, Medical University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Heinrich Leonhardt
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Colin L Stewart
- Institute of Medical Biology, 8A Biomedical Grove and Dept of Biological Sciences, NUS, 138648, Singapore.
| | - Boris Joffe
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
| | - Irina Solovei
- Department of Biology II, Ludwig-Maximilians-University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany.
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40
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Ioannou D, Millan NM, Jordan E, Tempest HG. A new model of sperm nuclear architecture following assessment of the organization of centromeres and telomeres in three-dimensions. Sci Rep 2017; 7:41585. [PMID: 28139771 PMCID: PMC5282497 DOI: 10.1038/srep41585] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 12/21/2016] [Indexed: 01/01/2023] Open
Abstract
The organization of chromosomes in sperm nuclei has been proposed to possess a unique “hairpin-loop” arrangement, which is hypothesized to aid in the ordered exodus of the paternal genome following fertilization. This study simultaneously assessed the 3D and 2D radial and longitudinal organization of telomeres, centromeres, and investigated whether chromosomes formed the same centromere clusters in sperm cells. Reproducible radial and longitudinal non-random organization was observed for all investigated loci using both 3D and 2D approaches in multiple subjects. We report novel findings, with telomeres and centromeres being localized throughout the nucleus but demonstrating roughly a 1:1 distribution in the nuclear periphery and the intermediate regions with <15% occupying the nuclear interior. Telomeres and centromeres were observed to aggregate in sperm nuclei, forming an average of 20 and 7 clusters, respectively. Reproducible
longitudinal organization demonstrated preferential localization of telomeres and centromeres in the mid region of the sperm cell. Preliminary evidence is also provided to support the hypothesis that specific chromosomes preferentially form the same centromere clusters. The more segmental distribution of telomeres and centromeres as described in this study could more readily accommodate and facilitate the sequential exodus of paternal chromosomes following fertilization.
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Affiliation(s)
- Dimitrios Ioannou
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Nicole M Millan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Elizabeth Jordan
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Helen G Tempest
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA.,Biomolecular Sciences Institute, Florida International University, Miami, FL, USA
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41
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de Las Heras JI, Zuleger N, Batrakou DG, Czapiewski R, Kerr ARW, Schirmer EC. Tissue-specific NETs alter genome organization and regulation even in a heterologous system. Nucleus 2017; 8:81-97. [PMID: 28045568 PMCID: PMC5287206 DOI: 10.1080/19491034.2016.1261230] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Different cell types exhibit distinct patterns of 3D genome organization that correlate with changes in gene expression in tissue and differentiation systems. Several tissue-specific nuclear envelope transmembrane proteins (NETs) have been found to influence the spatial positioning of genes and chromosomes that normally occurs during tissue differentiation. Here we study 3 such NETs: NET29, NET39, and NET47, which are expressed preferentially in fat, muscle and liver, respectively. We found that even when exogenously expressed in a heterologous system they can specify particular genome organization patterns and alter gene expression. Each NET affected largely different subsets of genes. Notably, the liver-specific NET47 upregulated many genes in HT1080 fibroblast cells that are normally upregulated in hepatogenesis, showing that tissue-specific NETs can favor expression patterns associated with the tissue where the NET is normally expressed. Similarly, global profiling of peripheral chromatin after exogenous expression of these NETs using lamin B1 DamID revealed that each NET affected the nuclear positioning of distinct sets of genomic regions with a significant tissue-specific component. Thus NET influences on genome organization can contribute to gene expression changes associated with differentiation even in the absence of other factors and overt cellular differentiation changes.
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Affiliation(s)
- Jose I de Las Heras
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Nikolaj Zuleger
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Dzmitry G Batrakou
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Rafal Czapiewski
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Alastair R W Kerr
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
| | - Eric C Schirmer
- a The Wellcome Trust Centre for Cell Biology , University of Edinburgh , Edinburgh , UK
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Rif1-Dependent Regulation of Genome Replication in Mammals. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1042:259-272. [DOI: 10.1007/978-981-10-6955-0_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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43
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Watson LA, Tsai LH. In the loop: how chromatin topology links genome structure to function in mechanisms underlying learning and memory. Curr Opin Neurobiol 2016; 43:48-55. [PMID: 28024185 DOI: 10.1016/j.conb.2016.12.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/01/2016] [Accepted: 12/05/2016] [Indexed: 12/18/2022]
Abstract
Different aspects of learning, memory, and cognition are regulated by epigenetic mechanisms such as covalent DNA modifications and histone post-translational modifications. More recently, the modulation of chromatin architecture and nuclear organization is emerging as a key factor in dynamic transcriptional regulation of the post-mitotic neuron. For instance, neuronal activity induces relocalization of gene loci to 'transcription factories', and specific enhancer-promoter looping contacts allow for precise transcriptional regulation. Moreover, neuronal activity-dependent DNA double-strand break formation in the promoter of immediate early genes appears to overcome topological constraints on transcription. Together, these findings point to a critical role for genome topology in integrating dynamic environmental signals to define precise spatiotemporal gene expression programs supporting cognitive processes.
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Affiliation(s)
| | - Li-Huei Tsai
- Picower Institute for Learning and Memory, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 46, Room 4235A, Cambridge, MA 02139, USA.
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44
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Huang R, Langdon SP, Tse M, Mullen P, Um IH, Faratian D, Harrison DJ. The role of HDAC2 in chromatin remodelling and response to chemotherapy in ovarian cancer. Oncotarget 2016; 7:4695-711. [PMID: 26683361 PMCID: PMC4826236 DOI: 10.18632/oncotarget.6618] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/26/2015] [Indexed: 12/29/2022] Open
Abstract
Chromatin undergoes structural changes in response to extracellular and environmental signals. We observed changes in nuclear morphology in cancer tissue biopsied after chemotherapy and hypothesised that these DNA damage-induced changes are mediated by histone deacetylases (HDACs). Nuclear morphological changes in cell lines (PE01 and PE04 models) and a xenograft model (OV1002) were measured in response to platinum chemotherapy by image analysis of nuclear texture. HDAC2 expression increased in PEO1 cells treated with cisplatin at 24h, which was accompanied by increased expression of heterochromatin protein 1 (HP1). HDAC2 and HP1 expression were also increased after carboplatin treatment in the OV1002 carboplatin-sensitive xenograft model but not in the insensitive HOX424 model. Expression of DNA damage response pathways (pBRCA1, γH2AX, pATM, pATR) showed time-dependent changes after cisplatin treatment. HDAC2 knockdown by siRNA reduced HP1 expression, induced DNA double strand breaks (DSB) measured by γH2AX, and interfered with the activation of DNA damage response induced by cisplatin. Furthermore, HDAC2 depletion affected γH2AX foci formation, cell cycle distribution, and apoptosis triggered by cisplatin, and was additive to the inhibitory effect of cisplatin in cell lines. By inhibiting expression of HDAC2, reversible alterations in chromatin patterns during cisplatin treatment were observed. These results demonstrate quantifiable alterations in nuclear morphology after chemotherapy, and implicate HDAC2 in higher order chromatin changes and cellular DNA damage responses in ovarian cancer cells in vitro and in vivo.
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Affiliation(s)
- Rui Huang
- Division of Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Simon P Langdon
- Division of Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Matthew Tse
- Division of Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Peter Mullen
- School of Medicine, University of St Andrews, St Andrews, Fife KY16 9TF, UK
| | - In Hwa Um
- School of Medicine, University of St Andrews, St Andrews, Fife KY16 9TF, UK
| | - Dana Faratian
- Division of Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - David J Harrison
- School of Medicine, University of St Andrews, St Andrews, Fife KY16 9TF, UK
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45
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Medrano-Fernández A, Barco A. Nuclear organization and 3D chromatin architecture in cognition and neuropsychiatric disorders. Mol Brain 2016; 9:83. [PMID: 27595843 PMCID: PMC5011999 DOI: 10.1186/s13041-016-0263-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 08/06/2016] [Indexed: 01/08/2023] Open
Abstract
The current view of neuroplasticity depicts the changes in the strength and number of synaptic connections as the main physical substrate for behavioral adaptation to new experiences in a changing environment. Although transcriptional regulation is known to play a role in these synaptic changes, the specific contribution of activity-induced changes to both the structure of the nucleus and the organization of the genome remains insufficiently characterized. Increasing evidence indicates that plasticity-related genes may work in coordination and share architectural and transcriptional machinery within discrete genomic foci. Here we review the molecular and cellular mechanisms through which neuronal nuclei structurally adapt to stimuli and discuss how the perturbation of these mechanisms can trigger behavioral malfunction.
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Affiliation(s)
- Alejandro Medrano-Fernández
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n. Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Angel Barco
- Instituto de Neurociencias (Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n. Sant Joan d'Alacant, 03550, Alicante, Spain.
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46
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Robin JD, Magdinier F. Physiological and Pathological Aging Affects Chromatin Dynamics, Structure and Function at the Nuclear Edge. Front Genet 2016; 7:153. [PMID: 27602048 PMCID: PMC4993774 DOI: 10.3389/fgene.2016.00153] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/08/2016] [Indexed: 01/29/2023] Open
Abstract
Lamins are intermediate filaments that form a complex meshwork at the inner nuclear membrane. Mammalian cells express two types of Lamins, Lamins A/C and Lamins B, encoded by three different genes, LMNA, LMNB1, and LMNB2. Mutations in the LMNA gene are associated with a group of phenotypically diverse diseases referred to as laminopathies. Lamins interact with a large number of binding partners including proteins of the nuclear envelope but also chromatin-associated factors. Lamins not only constitute a scaffold for nuclear shape, rigidity and resistance to stress but also contribute to the organization of chromatin and chromosomal domains. We will discuss here the impact of A-type Lamins loss on alterations of chromatin organization and formation of chromatin domains and how disorganization of the lamina contributes to the patho-physiology of premature aging syndromes.
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Affiliation(s)
- Jérôme D Robin
- IRCAN, CNRS UMR 7284/INSERM U1081, Faculté de Médecine Nice, France
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47
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Pueschel R, Coraggio F, Meister P. From single genes to entire genomes: the search for a function of nuclear organization. Development 2016; 143:910-23. [PMID: 26980791 DOI: 10.1242/dev.129007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The existence of different domains within the nucleus has been clear from the time, in the late 1920s, that heterochromatin and euchromatin were discovered. The observation that heterochromatin is less transcribed than euchromatin suggested that microscopically identifiable structures might correspond to functionally different domains of the nucleus. Until 15 years ago, studies linking gene expression and subnuclear localization were limited to a few genes. As we discuss in this Review, new genome-wide techniques have now radically changed the way nuclear organization is analyzed. These have provided a much more detailed view of functional nuclear architecture, leading to the emergence of a number of new paradigms of chromatin folding and how this folding evolves during development.
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Affiliation(s)
- Ringo Pueschel
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, 3012 Bern, Switzerland Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Francesca Coraggio
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, 3012 Bern, Switzerland Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland
| | - Peter Meister
- Cell Fate and Nuclear Organization, Institute of Cell Biology, University of Bern, 3012 Bern, Switzerland
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48
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Meaburn KJ. Spatial Genome Organization and Its Emerging Role as a Potential Diagnosis Tool. Front Genet 2016; 7:134. [PMID: 27507988 PMCID: PMC4961005 DOI: 10.3389/fgene.2016.00134] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/13/2016] [Indexed: 12/12/2022] Open
Abstract
In eukaryotic cells the genome is highly spatially organized. Functional relevance of higher order genome organization is implied by the fact that specific genes, and even whole chromosomes, alter spatial position in concert with functional changes within the nucleus, for example with modifications to chromatin or transcription. The exact molecular pathways that regulate spatial genome organization and the full implication to the cell of such an organization remain to be determined. However, there is a growing realization that the spatial organization of the genome can be used as a marker of disease. While global genome organization patterns remain largely conserved in disease, some genes and chromosomes occupy distinct nuclear positions in diseased cells compared to their normal counterparts, with the patterns of reorganization differing between diseases. Importantly, mapping the spatial positioning patterns of specific genomic loci can distinguish cancerous tissue from benign with high accuracy. Genome positioning is an attractive novel biomarker since additional quantitative biomarkers are urgently required in many cancer types. Current diagnostic techniques are often subjective and generally lack the ability to identify aggressive cancer from indolent, which can lead to over- or under-treatment of patients. Proof-of-principle for the use of genome positioning as a diagnostic tool has been provided based on small scale retrospective studies. Future large-scale studies are required to assess the feasibility of bringing spatial genome organization-based diagnostics to the clinical setting and to determine if the positioning patterns of specific loci can be useful biomarkers for cancer prognosis. Since spatial reorganization of the genome has been identified in multiple human diseases, it is likely that spatial genome positioning patterns as a diagnostic biomarker may be applied to many diseases.
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Affiliation(s)
- Karen J. Meaburn
- Cell Biology of Genomes Group, National Cancer Institute, National Institutes of HealthBethesda, MD, USA
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Gonzalez-Sandoval A, Gasser SM. Mechanism of chromatin segregation to the nuclear periphery in C. elegans embryos. WORM 2016; 5:e1190900. [PMID: 27695653 DOI: 10.1080/21624054.2016.1190900] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 05/06/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
Abstract
In eukaryotic organisms, gene regulation occurs in the context of chromatin. In the interphase nucleus, euchromatin and heterochromatin occupy distinct space during cell differentiation, with heterochromatin becoming enriched at the nuclear and nucleolar peripheries. This organization is thought to fine-tune gene expression. To elucidate the mechanisms that govern this level of genome organization, screens were carried out in C. elegans which monitored the loss of heterochromatin sequestration at the nuclear periphery. This led to the identification of a novel chromodomain protein, CEC-4 (Caenorhabditis elegans chromodomain protein 4) that mediates the anchoring of H3K9 methylation-bearing chromatin at the nuclear periphery in early to mid-stage embryos. Surprisingly, the loss of CEC-4 does not derepress genes found in heterochromatic domains, nor does it affect differentiation under standard laboratory conditions. On the other hand, CEC-4 contributes to the efficiency with which muscle differentiation is induced following ectopic expression of the master regulator, HLH-1. This is one of the first phenotypes specifically attributed to the ablation of heterochromatin anchoring.
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Affiliation(s)
- Adriana Gonzalez-Sandoval
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
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50
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Czapiewski R, Robson MI, Schirmer EC. Anchoring a Leviathan: How the Nuclear Membrane Tethers the Genome. Front Genet 2016; 7:82. [PMID: 27200088 PMCID: PMC4859327 DOI: 10.3389/fgene.2016.00082] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/20/2016] [Indexed: 12/21/2022] Open
Abstract
It is well established that the nuclear envelope has many distinct direct connections to chromatin that contribute to genome organization. The functional consequences of genome organization on gene regulation are less clear. Even less understood is how interactions of lamins and nuclear envelope transmembrane proteins (NETs) with chromatin can produce anchoring tethers that can withstand the physical forces of and on the genome. Chromosomes are the largest molecules in the cell, making megadalton protein structures like the nuclear pore complexes and ribosomes seem small by comparison. Thus to withstand strong forces from chromosome dynamics an anchoring tether is likely to be much more complex than a single protein-protein or protein-DNA interaction. Here we will briefly review known NE-genome interactions that likely contribute to spatial genome organization, postulate in the context of experimental data how these anchoring tethers contribute to gene regulation, and posit several hypotheses for the physical nature of these tethers that need to be investigated experimentally. Significantly, disruption of these anchoring tethers and the subsequent consequences for gene regulation could explain how mutations in nuclear envelope proteins cause diseases ranging from muscular dystrophy to lipodystrophy to premature aging progeroid syndromes. The two favored hypotheses for nuclear envelope protein involvement in disease are (1) weakening nuclear and cellular mechanical stability, and (2) disrupting genome organization and gene regulation. Considerable experimental support has been obtained for both. The integration of both mechanical and gene expression defects in the disruption of anchoring tethers could provide a unifying hypothesis consistent with both.
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Affiliation(s)
| | | | - Eric C. Schirmer
- The Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, University of EdinburghEdinburgh, UK
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