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Marin H, Simental E, Allen C, Martin E, Panning B, Al-Sady B, Buchwalter A. The nuclear periphery confers repression on H3K9me2-marked genes and transposons to shape cell fate. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.08.602542. [PMID: 39026839 PMCID: PMC11257442 DOI: 10.1101/2024.07.08.602542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Heterochromatic loci marked by histone H3 lysine 9 dimethylation (H3K9me2) are enriched at the nuclear periphery in metazoans, but the effect of spatial position on heterochromatin function has not been defined. Here, we remove three nuclear lamins and lamin B receptor (LBR) in mouse embryonic stem cells (mESCs) and show that heterochromatin detaches from the nuclear periphery. Mutant mESCs sustain naïve pluripotency and maintain H3K9me2 across the genome but cannot repress H3K9me2-marked genes or transposons. Further, mutant cells fail to differentiate into epiblast-like cells (EpiLCs), a transition that requires the expansion of H3K9me2 across the genome. Mutant EpiLCs can silence naïve pluripotency genes and activate epiblast-stage genes. However, H3K9me2 cannot repress markers of alternative fates, including primitive endoderm. We conclude that the nuclear periphery controls the spatial position, dynamic remodeling, and repressive capacity of H3K9me2-marked heterochromatin to shape cell fate decisions.
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Affiliation(s)
- Harold Marin
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Eric Simental
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
- Department of Biochemistry, University of California, San Francisco, CA, USA
| | - Charlie Allen
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Eric Martin
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
| | - Barbara Panning
- Department of Biochemistry, University of California, San Francisco, CA, USA
| | - Bassem Al-Sady
- Department of Microbiology and Immunology, University of California, San Francisco, CA, USA
| | - Abigail Buchwalter
- Cardiovascular Research Institute, University of California, San Francisco, CA, USA
- Department of Physiology, University of California, San Francisco, CA, USA
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2
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Dulka K, Lajkó N, Nacsa K, Gulya K. Opposite and Differently Altered Postmortem Changes in H3 and H3K9me3 Patterns in the Rat Frontal Cortex and Hippocampus. EPIGENOMES 2024; 8:11. [PMID: 38534795 DOI: 10.3390/epigenomes8010011] [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: 01/22/2024] [Revised: 02/18/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024] Open
Abstract
Temporal and spatial epigenetic modifications in the brain occur during ontogenetic development, pathophysiological disorders, and aging. When epigenetic marks, such as histone methylations, in brain autopsies or biopsy samples are studied, it is critical to understand their postmortem/surgical stability. For this study, the frontal cortex and hippocampus of adult rats were removed immediately (controls) or after a postmortem delay of 15, 30, 60, 90, 120, or 150 min. The patterns of unmodified H3 and its trimethylated form H3K9me3 were analyzed in frozen samples for Western blot analysis and in formalin-fixed tissues embedded in paraffin for confocal microscopy. We found that both the unmodified H3 and H3K9me3 showed time-dependent but opposite changes and were altered differently in the frontal cortex and hippocampus with respect to postmortem delay. In the frontal cortex, the H3K9me3 marks increased approximately 450% with a slow parallel 20% decrease in the unmodified H3 histones after 150 min. In the hippocampus, the change was opposite, since H3K9me3 marks decreased steadily by approximately 65% after 150 min with a concomitant rapid increase of 20-25% in H3 histones at the same time. Confocal microscopy located H3K9me3 marks in the heterochromatic regions of the nuclei of all major cell types in the control brains: oligodendrocytes, astrocytes, neurons, and microglia. Therefore, epigenetic marks could be affected differently by postmortem delay in different parts of the brain.
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Affiliation(s)
- Karolina Dulka
- Department of Cell Biology and Molecular Medicine, University of Szeged, 6720 Szeged, Hungary
| | - Noémi Lajkó
- Department of Cell Biology and Molecular Medicine, University of Szeged, 6720 Szeged, Hungary
| | - Kálmán Nacsa
- Department of Cell Biology and Molecular Medicine, University of Szeged, 6720 Szeged, Hungary
| | - Karoly Gulya
- Department of Cell Biology and Molecular Medicine, University of Szeged, 6720 Szeged, Hungary
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3
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Mello MLS. Nuclear Morphofunctional Organization and Epigenetic Characteristics in Somatic Cells of T. infestans (Klug, 1834). Pathogens 2023; 12:1030. [PMID: 37623990 PMCID: PMC10460038 DOI: 10.3390/pathogens12081030] [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: 07/16/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
Triatoma infestans (Klug) is an insect recognized as not only an important vector of South American trypanosomiasis (Chagas disease) but also a model of specific cellular morphofunctional organization and epigenetic characteristics. The purpose of the present review is to highlight certain cellular processes that are particularly unveiled in T. infestans, such as the following: (1) somatic polyploidy involving nuclear and cell fusions that generate giant nuclei; (2) diversification of nuclear phenotypes in the Malpighian tubules during insect development; (3) heterochromatin compartmentalization into large bodies with specific spatial distribution and presumed mobility in the cell nuclei; (4) chromatin remodeling and co-occurrence of necrosis and apoptosis in the Malpighian tubules under stress conditions; (5) epigenetic markers; and (6) response of heterochromatin to valproic acid, an epidrug that inhibits histone deacetylases and induces DNA demethylation in other cell systems. These cellular processes and epigenetic characteristics emphasize the role of T. infestans as an attractive model for cellular research. A limitation of these studies is the availability of insect supply by accredited insectaries. For studies that require the injection of drugs, the operator's dexterity to perform insect manipulation is necessary, especially if young nymphs are used. For studies involving in vitro cultivation of insect organs, the culture medium should be carefully selected to avoid inconsistent results.
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Affiliation(s)
- Maria Luiza S Mello
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil
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4
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Duan L, Chen YA, Liang Y, Chen Z, Lu J, Fang Y, Cao J, Lu J, Zhao H, Pong RC, Hernandez E, Kapur P, Tran TAT, Smith T, Martinez ED, Ahn JM, Hsieh JT, Luo JH, Liu ZP. Therapeutic targeting of histone lysine demethylase KDM4B blocks the growth of castration-resistant prostate cancer. Biomed Pharmacother 2023; 158:114077. [PMID: 36495660 PMCID: PMC10926092 DOI: 10.1016/j.biopha.2022.114077] [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: 10/13/2022] [Revised: 11/24/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Epigenetics is an emerging mechanism for tumorigenesis. Treatment that targets epigenetic regulators is becoming an attractive strategy for cancer therapy. The role of epigenetic therapy in prostate cancer (PCa) remains elusive. Previously we demonstrated that upregulation of histone lysine demethylase KDM4B correlated with the appearance of castration resistant prostate cancer (CRPC) and identified a small molecular inhibitor of KDM4B, B3. In this study, we further investigated the role of KDM4B in promoting PCa progression and tested the efficacy of B3 using clinically relevant PCa models including PCa cell line LNCaP and 22Rv1 and xenografts derived from these cell lines. In loss and gain-functional studies of KDM4B in PCa cells, we found that overexpression of KDM4B in LNCaP cells enhanced its tumorigenicity whereas knockdown of KDM4B in 22Rv1 cells reduced tumor growth in castrated mice. B3 suppressed the growth of 22Rv1 xenografts and sensitized tumor to anti-androgen receptor (AR) antagonist enzalutamide inhibition. B3 also inhibited 22Rv1 tumor growth synergistically with rapamycin, leading to cell apoptosis. Comparative transcriptomic analysis performed on KDM4B knockdown and B3-treated 22Rv1 cells revealed that B3 inhibited both H3K9me3 and H3K27me3 demethylase activities. Our studies establish KDM4B as a target for CRPC and B3 as a potential therapeutic agent. B3 as monotherapy or in combination with other anti-PCa therapeutics offers proof of principle for the clinical translation of epigenetic therapy targeting KDMs for CRPC patients.
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Affiliation(s)
- Lingling Duan
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yu-An Chen
- Department of Urology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yanping Liang
- Department of Urology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Zhenhua Chen
- Department of Urology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jun Lu
- Department of Urology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Yong Fang
- Department of Urology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China
| | - Jiazheng Cao
- Department of Urology, Jiangmen Hospital, Sun Yat-Sen University, Jiangmen 529030, China
| | - Jian Lu
- Department of Urology, Jiangmen Hospital, Sun Yat-Sen University, Jiangmen 529030, China
| | - Hongwei Zhao
- Department of Urology, Affiliated Yantai Yuhuangding Hospital, Qingdao University Medical College, Yantai 264000, China
| | - Rey-Chen Pong
- Department of Urology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Elizabeth Hernandez
- Department of Urology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Payal Kapur
- Department of Pathology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tram Anh T Tran
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tristan Smith
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Elisabeth D Martinez
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jung-Mo Ahn
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Jer-Tsong Hsieh
- Department of Urology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jun-Hang Luo
- Department of Urology, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
| | - Zhi-Ping Liu
- Department of Internal Medicine, UT Southwestern Medical Center, Dallas, TX 75390, USA; Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
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5
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Rocha MA, de Campos Vidal B, Mello MLS. Sodium Valproate Modulates the Methylation Status of Lysine Residues 4, 9 and 27 in Histone H3 of HeLa Cells. Curr Mol Pharmacol 2023; 16:197-210. [PMID: 35297358 DOI: 10.2174/1874467215666220316110405] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/27/2021] [Accepted: 01/12/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Valproic acid/sodium valproate (VPA), a well-known anti-epileptic agent, inhibits histone deacetylases, induces histone hyperacetylation, promotes DNA demethylation, and affects the histone methylation status in some cell models. Histone methylation profiles have been described as potential markers for cervical cancer prognosis. However, histone methylation markers that can be studied in a cervical cancer cell line, like HeLa cells, have not been investigated following treatment with VPA. METHODS In this study, the effect of 0.5 mM and 2.0 mM VPA for 24 h on H3K4me2/me3, H3K9me/me2 and H3K27me/me3 signals as well as on KMT2D, EZH2, and KDM3A gene expression was investigated using confocal microscopy, Western blotting, and RT-PCR. Histone methylation changes were also investigated by Fourier-transform infrared spectroscopy (FTIR). RESULTS We found that VPA induces increased levels of H3K4me2/me3 and H3K9me, which are indicative of chromatin activation. Particularly, H3K4me2 markers appeared intensified close to the nuclear periphery, which may suggest their implication in increased transcriptional memory. The abundance of H3K4me2/me3 in the presence of VPA was associated with increased methyltransferase KMT2D gene expression. VPA induced hypomethylation of H3K9me2, which is associated with gene silencing, and concomitant with the demethylase KDM3A, it increased gene expression. Although VPA induces increased H3K27me/me3 levels, it is suggested that the role of the methyltransferase EZH2 in this context could be affected by interactions with this drug. CONCLUSION Histone FTIR spectra were not affected by VPA under present experimental conditions. Whether our epigenetic results are consistent with VPA affecting the aggressive tumorous state of HeLa cells, further investigation is required.
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Affiliation(s)
- Marina Amorim Rocha
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), 13083-862 Campinas, SP, Brazil
| | - Benedicto de Campos Vidal
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), 13083-862 Campinas, SP, Brazil
| | - Maria Luiza Silveira Mello
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), 13083-862 Campinas, SP, Brazil
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6
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Pathological Nuclear Hallmarks in Dentate Granule Cells of Alzheimer’s Patients: A Biphasic Regulation of Neurogenesis. Int J Mol Sci 2022; 23:ijms232112873. [PMID: 36361662 PMCID: PMC9654738 DOI: 10.3390/ijms232112873] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/29/2022] Open
Abstract
The dentate gyrus (DG) of the human hippocampus is a complex and dynamic structure harboring mature and immature granular neurons in diverse proliferative states. While most mammals show persistent neurogenesis through adulthood, human neurogenesis is still under debate. We found nuclear alterations in granular cells in autopsied human brains, detected by immunohistochemistry. These alterations differ from those reported in pyramidal neurons of the hippocampal circuit. Aging and early AD chromatin were clearly differentiated by the increased epigenetic markers H3K9me3 (heterochromatin suppressive mark) and H3K4me3 (transcriptional euchromatin mark). At early AD stages, lamin B2 was redistributed to the nucleoplasm, indicating cell-cycle reactivation, probably induced by hippocampal nuclear pathology. At intermediate and late AD stages, higher lamin B2 immunopositivity in the perinucleus suggests fewer immature neurons, less neurogenesis, and fewer adaptation resources to environmental factors. In addition, senile samples showed increased nuclear Tau interacting with aged chromatin, likely favoring DNA repair and maintaining genomic stability. However, at late AD stages, the progressive disappearance of phosphorylated Tau forms in the nucleus, increased chromatin disorganization, and increased nuclear autophagy support a model of biphasic neurogenesis in AD. Therefore, designing therapies to alleviate the neuronal nuclear pathology might be the only pathway to a true rejuvenation of brain circuits.
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7
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Establishment of H3K9-methylated heterochromatin and its functions in tissue differentiation and maintenance. Nat Rev Mol Cell Biol 2022; 23:623-640. [PMID: 35562425 PMCID: PMC9099300 DOI: 10.1038/s41580-022-00483-w] [Citation(s) in RCA: 136] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2022] [Indexed: 12/14/2022]
Abstract
Heterochromatin is characterized by dimethylated or trimethylated histone H3 Lys9 (H3K9me2 or H3K9me3, respectively) and is found at transposable elements, satellite repeats and genes, where it ensures their transcriptional silencing. The histone methyltransferases (HMTs) that methylate H3K9 — in mammals Suppressor of variegation 3–9 homologue 1 (SUV39H1), SUV39H2, SET domain bifurcated 1 (SETDB1), SETDB2, G9A and G9A-like protein (GLP) — and the ‘readers’ of H3K9me2 or H3K9me3 are highly conserved and show considerable redundancy. Despite their redundancy, genetic ablation or mistargeting of an individual H3K9 methyltransferase can correlate with impaired cell differentiation, loss of tissue identity, premature aging and/or cancer. In this Review, we discuss recent advances in understanding the roles of the known H3K9-specific HMTs in ensuring transcriptional homeostasis during tissue differentiation in mammals. We examine the effects of H3K9-methylation-dependent gene repression in haematopoiesis, muscle differentiation and neurogenesis in mammals, and compare them with mechanistic insights obtained from the study of model organisms, notably Caenorhabditis elegans and Drosophila melanogaster. In all these organisms, H3K9-specific HMTs have both unique and redundant roles that ensure the maintenance of tissue integrity by restricting the binding of transcription factors to lineage-specific promoters and enhancer elements. Histone H3 Lys9 (H3K9)-methylated heterochromatin ensures transcriptional silencing of repetitive elements and genes, and its deregulation leads to impaired cell and tissue identity, premature aging and cancer. Recent studies in mammals clarified the roles H3K9-specific histone methyltransferases in ensuring transcriptional homeostasis during tissue differentiation.
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8
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Richards L, Das S, Nordman JT. Rif1-Dependent Control of Replication Timing. Genes (Basel) 2022; 13:genes13030550. [PMID: 35328102 PMCID: PMC8955891 DOI: 10.3390/genes13030550] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/15/2022] [Accepted: 03/18/2022] [Indexed: 02/01/2023] Open
Abstract
Successful duplication of the genome requires the accurate replication of billions of base pairs of DNA within a relatively short time frame. Failure to accurately replicate the genome results in genomic instability and a host of diseases. To faithfully and rapidly replicate the genome, DNA replication must be tightly regulated and coordinated with many other nuclear processes. These regulations, however, must also be flexible as replication kinetics can change through development and differentiation. Exactly how DNA replication is regulated and how this regulation changes through development is an active field of research. One aspect of genome duplication where much remains to be discovered is replication timing (RT), which dictates when each segment of the genome is replicated during S phase. All organisms display some level of RT, yet the precise mechanisms that govern RT remain are not fully understood. The study of Rif1, a protein that actively regulates RT from yeast to humans, provides a key to unlock the underlying molecular mechanisms controlling RT. The paradigm for Rif1 function is to delay helicase activation within certain regions of the genome, causing these regions to replicate late in S phase. Many questions, however, remain about the intricacies of Rif1 function. Here, we review the current models for the activity of Rif1 with the goal of trying to understand how Rif1 functions to establish the RT program.
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9
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Fabian-Morales E, Vallejo-Escamilla D, Gudiño A, Rodríguez A, González-Barrios R, Rodríguez Torres YL, Castro Hernández C, de la Torre-Luján AH, Oliva-Rico DA, Ornelas Guzmán EC, López Saavedra A, Frias S, Herrera LA. Large-scale topological disruption of chromosome territories 9 and 22 is associated with nonresponse to treatment in CML. Int J Cancer 2021; 150:1455-1470. [PMID: 34913480 PMCID: PMC9303775 DOI: 10.1002/ijc.33903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 11/07/2021] [Accepted: 12/09/2021] [Indexed: 11/29/2022]
Abstract
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm defined by the presence of t(9;22) translocation whose origin has been associated with the tridimensional genome organization. This rearrangement leads to the fusion of BCR and ABL1 genes giving rise to a chimeric protein with constitutive kinase activity. Imatinib, a tyrosine kinase inhibitor (TKI), is used as a first‐line treatment for CML, though ~40% of CML patients do not respond. Here, using structured illumination microscopy (SIM) and 3D reconstruction, we studied the 3D organization patterns of the ABL1 and BCR genes, and their chromosome territories (CTs) CT9 and CT22, in CD34+ cells from CML patients that responded or not to TKI. We found that TKI resistance in CML is associated with high levels of structural disruption of CT9 and CT22 in CD34+ cells, increased CT volumes (especially for CT22), intermingling between CT9 and CT22, and an open‐chromatin epigenetic mark in CT22. Altogether our results suggest that large‐scale disruption of CT9 and CT22 correlates with the clinical response of CML patients, which could be translated into a potential prognostic marker of response to treatment in this disease and provide novel insights into the mechanisms underlying resistance to TKI in CML.
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Affiliation(s)
- Eunice Fabian-Morales
- Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | - David Vallejo-Escamilla
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | - Adriana Gudiño
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Alfredo Rodríguez
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico.,Instituto Nacional de Pediatría (INP), Mexico City, Mexico
| | - Rodrigo González-Barrios
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | - Yameli L Rodríguez Torres
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Clementina Castro Hernández
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | | | - Diego A Oliva-Rico
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | - Erandhi C Ornelas Guzmán
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico
| | - Alejandro López Saavedra
- Unidad de Aplicaciones Avanzadas en Microscopía (ADMiRA), Instituto Nacional de Cancerología (INCan), Red de Apoyo a la Investigación (RAI), Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico.,Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico
| | - Sara Frias
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico.,Laboratorio de Citogenética, Instituto Nacional de Pediatría (INP), Mexico City, Mexico
| | - Luis A Herrera
- Unidad de Investigación Biomédica en Cáncer, Instituto Nacional de Cancerología (INCan), Mexico City, Mexico.,Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apartado Postal 70228, Mexico City, Mexico.,Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, Mexico
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10
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Jiang Z, Zhu Z, Zhao M, Wang W, Li H, Liu D, Pan F. H3K9me2 regulation of BDNF expression in the hippocampus and medial prefrontal cortex is involved in the depressive-like phenotype induced by maternal separation in male rats. Psychopharmacology (Berl) 2021; 238:2801-2813. [PMID: 34328517 DOI: 10.1007/s00213-021-05896-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 06/07/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Early life stress (ELS) induces a depressive-like phenotype and increases the risk of depression. Brain-derived neurotrophic factor (BDNF) has been confirmed to be involved in the pathophysiology of depression. However, the mechanism by which ELS alters the epigenetic regulation of BDNF and changes susceptibility to depression has not been fully clarified. METHODS The present study used maternal separation (MS) and chronic unpredicted mild stress (CUMS) to establish an MS animal model and a depressive animal model. We assessed depressive-like behaviours, including anhedonia, locomotor activity, anxiety-like behaviour, and spatial memory, using the sucrose preference test, the open field test, the elevated plus maze test, and the Morris water maze test. We also investigated BDNF and H3K9me2 expression in the hippocampus and medial prefrontal cortex (mPFC) by immunohistochemistry, western blotting, and qPCR analysis. Additionally, we used Unc0642, a small molecule inhibitor of histone methyltransferase (G9a), as an intervention. RESULTS The results showed that CUMS induced depressive-like behaviours in rats and resulted in increased H3K9me2 expression and decreased BDNF expression in the hippocampus and mPFC. More importantly, adult MS rats experiencing CUMS had more severe depressive behaviours, had higher expression of H3K9me2 in the hippocampus and mPFC, and had lower expression of BDNF in the hippocampus and mPFC. In addition, administration of the G9a inhibitor reversed most of the changes. CONCLUSIONS Our study suggests that ELS changed BDNF and H3K9me2 expression in the rat brain, resulting in a depressive-like phenotype.
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Affiliation(s)
- Zhijun Jiang
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Zemeng Zhu
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Mingyue Zhao
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Wei Wang
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Haonan Li
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Dexiang Liu
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Fang Pan
- Department of Medical Psychology and Ethics, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, 44#, Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.
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11
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Smith CL, Poleshko A, Epstein JA. The nuclear periphery is a scaffold for tissue-specific enhancers. Nucleic Acids Res 2021; 49:6181-6195. [PMID: 34023908 PMCID: PMC8216274 DOI: 10.1093/nar/gkab392] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 04/26/2021] [Accepted: 04/29/2021] [Indexed: 02/06/2023] Open
Abstract
Nuclear architecture influences gene regulation and cell identity by controlling the three-dimensional organization of genes and their distal regulatory sequences, which may be far apart in linear space. The genome is functionally and spatially segregated in the eukaryotic nucleus with transcriptionally active regions in the nuclear interior separated from repressive regions, including those at the nuclear periphery. Here, we describe the identification of a novel type of nuclear peripheral chromatin domain that is enriched for tissue-specific transcriptional enhancers. Like other chromatin at the nuclear periphery, these regions are marked by H3K9me2. But unlike the nuclear peripheral Lamina-Associated Domains (LADs), these novel, enhancer-rich domains have limited Lamin B interaction. We therefore refer to them as H3K9me2-Only Domains (KODs). In mouse embryonic stem cells, KODs are found in Hi-C-defined A compartments and feature relatively accessible chromatin. KODs are characterized by low gene expression and enhancers located in these domains bear the histone marks of an inactive or poised state. These results indicate that KODs organize a subset of inactive, tissue-specific enhancers at the nuclear periphery. We hypothesize that KODs may play a role in facilitating and perhaps constraining the enhancer-promoter interactions underlying spatiotemporal regulation of gene expression programs in differentiation and development.
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Affiliation(s)
- Cheryl L Smith
- Department of Cell and Developmental Biology and Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104, USA
| | - Andrey Poleshko
- Department of Cell and Developmental Biology and Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104, USA
| | - Jonathan A Epstein
- Department of Medicine and Penn Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, PA 19104, USA
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12
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Histone Methylation Regulation in Neurodegenerative Disorders. Int J Mol Sci 2021; 22:ijms22094654. [PMID: 33925016 PMCID: PMC8125694 DOI: 10.3390/ijms22094654] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/11/2022] Open
Abstract
Advances achieved with molecular biology and genomics technologies have permitted investigators to discover epigenetic mechanisms, such as DNA methylation and histone posttranslational modifications, which are critical for gene expression in almost all tissues and in brain health and disease. These advances have influenced much interest in understanding the dysregulation of epigenetic mechanisms in neurodegenerative disorders. Although these disorders diverge in their fundamental causes and pathophysiology, several involve the dysregulation of histone methylation-mediated gene expression. Interestingly, epigenetic remodeling via histone methylation in specific brain regions has been suggested to play a critical function in the neurobiology of psychiatric disorders, including that related to neurodegenerative diseases. Prominently, epigenetic dysregulation currently brings considerable interest as an essential player in neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Amyotrophic lateral sclerosis (ALS) and drugs of abuse, including alcohol abuse disorder, where it may facilitate connections between genetic and environmental risk factors or directly influence disease-specific pathological factors. We have discussed the current state of histone methylation, therapeutic strategies, and future perspectives for these disorders. While not somatically heritable, the enzymes responsible for histone methylation regulation, such as histone methyltransferases and demethylases in neurons, are dynamic and reversible. They have become promising potential therapeutic targets to treat or prevent several neurodegenerative disorders. These findings, along with clinical data, may provide links between molecular-level changes and behavioral differences and provide novel avenues through which the epigenome may be targeted early on in people at risk for neurodegenerative disorders.
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13
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Bizhanova A, Kaufman PD. Close to the edge: Heterochromatin at the nucleolar and nuclear peripheries. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2021; 1864:194666. [PMID: 33307247 PMCID: PMC7855492 DOI: 10.1016/j.bbagrm.2020.194666] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/11/2020] [Accepted: 11/29/2020] [Indexed: 02/06/2023]
Abstract
Chromatin is a dynamic structure composed of DNA, RNA, and proteins, regulating storage and expression of the genetic material in the nucleus. Heterochromatin plays a crucial role in driving the three-dimensional arrangement of the interphase genome, and in preserving genome stability by maintaining a subset of the genome in a silent state. Spatial genome organization contributes to normal patterns of gene function and expression, and is therefore of broad interest. Mammalian heterochromatin, the focus of this review, mainly localizes at the nuclear periphery, forming Lamina-associated domains (LADs), and at the nucleolar periphery, forming Nucleolus-associated domains (NADs). Together, these regions comprise approximately one-half of mammalian genomes, and most but not all loci within these domains are stochastically placed at either of these two locations after exit from mitosis at each cell cycle. Excitement about the role of these heterochromatic domains in early development has recently been heightened by the discovery that LADs appear at some loci in the preimplantation mouse embryo prior to other chromosomal features like compartmental identity and topologically-associated domains (TADs). While LADs have been extensively studied and mapped during cellular differentiation and early embryonic development, NADs have been less thoroughly studied. Here, we summarize pioneering studies of NADs and LADs, more recent advances in our understanding of cis/trans-acting factors that mediate these localizations, and discuss the functional significance of these associations.
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Affiliation(s)
- Aizhan Bizhanova
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Paul D Kaufman
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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14
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Miura H, Takahashi S, Shibata T, Nagao K, Obuse C, Okumura K, Ogata M, Hiratani I, Takebayashi SI. Mapping replication timing domains genome wide in single mammalian cells with single-cell DNA replication sequencing. Nat Protoc 2020; 15:4058-4100. [PMID: 33230331 DOI: 10.1038/s41596-020-0378-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 07/02/2020] [Indexed: 01/03/2023]
Abstract
Replication timing (RT) domains are stable units of chromosome structure that are regulated in the context of development and disease. Conventional genome-wide RT mapping methods require many S-phase cells for either the effective enrichment of replicating DNA through bromodeoxyuridine (BrdU) immunoprecipitation or the determination of copy-number differences during S-phase, which precludes their application to non-abundant cell types and single cells. Here, we provide a simple, cost-effective, and robust protocol for single-cell DNA replication sequencing (scRepli-seq). The scRepli-seq methodology relies on whole-genome amplification (WGA) of genomic DNA (gDNA) from single S-phase cells and next-generation sequencing (NGS)-based determination of copy-number differences that arise between replicated and unreplicated DNA. Haplotype-resolved scRepli-seq, which distinguishes pairs of homologous chromosomes within a single cell, is feasible by using single-nucleotide polymorphism (SNP)/indel information. We also provide computational pipelines for quality control, normalization, and binarization of the scRepli-seq data. The experimental portion of this protocol (before sequencing) takes 3 d.
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Affiliation(s)
- Hisashi Miura
- Laboratory for Developmental Epigenetics, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan
| | - Saori Takahashi
- Laboratory for Developmental Epigenetics, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan
| | - Takahiro Shibata
- Department of Biochemistry and Proteomics, Graduate School of Medicine, Mie University, Tsu, Japan.,Laboratory of Molecular & Cellular Biology, Graduate School of Bioresources, Mie University, Tsu, Japan
| | - Koji Nagao
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Chikashi Obuse
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Katsuzumi Okumura
- Laboratory of Molecular & Cellular Biology, Graduate School of Bioresources, Mie University, Tsu, Japan
| | - Masato Ogata
- Department of Biochemistry and Proteomics, Graduate School of Medicine, Mie University, Tsu, Japan
| | - Ichiro Hiratani
- Laboratory for Developmental Epigenetics, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan.
| | - Shin-Ichiro Takebayashi
- Department of Biochemistry and Proteomics, Graduate School of Medicine, Mie University, Tsu, Japan. .,Laboratory of Molecular & Cellular Biology, Graduate School of Bioresources, Mie University, Tsu, Japan.
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15
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Chiang M, Michieletto D, Brackley CA, Rattanavirotkul N, Mohammed H, Marenduzzo D, Chandra T. Polymer Modeling Predicts Chromosome Reorganization in Senescence. Cell Rep 2020; 28:3212-3223.e6. [PMID: 31533042 PMCID: PMC6859504 DOI: 10.1016/j.celrep.2019.08.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 05/10/2019] [Accepted: 08/13/2019] [Indexed: 12/13/2022] Open
Abstract
Lamina-associated domains (LADs) cover a large part of the human genome and are thought to play a major role in shaping the nuclear architectural landscape. Here, we perform polymer simulations, microscopy, and mass spectrometry to dissect the roles played by heterochromatin- and lamina-mediated interactions in nuclear organization. Our model explains the conventional organization of heterochromatin and euchromatin in growing cells and the pathological organization found in oncogene-induced senescence and progeria. We show that the experimentally observed changes in the locality of contacts in senescent and progeroid cells can be explained as arising due to phase transitions in the system. Within our simulations, LADs are highly stochastic, as in experiments. Our model suggests that, once established, the senescent phenotype should be metastable even if lamina-mediated interactions were reinstated. Overall, our simulations uncover a generic physical mechanism that can regulate heterochromatin segregation and LAD formation in a wide range of mammalian nuclei.
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Affiliation(s)
- Michael Chiang
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
| | - Davide Michieletto
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK; MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK; Centre for Mathematical Biology, and Department of Mathematical Sciences, University of Bath, North Road, Bath BA2 7AY, UK
| | - Chris A Brackley
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK
| | - Nattaphong Rattanavirotkul
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK
| | - Hisham Mohammed
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA
| | - Davide Marenduzzo
- SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK
| | - Tamir Chandra
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK.
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16
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Lee MY, Lee J, Hyeon SJ, Cho H, Hwang YJ, Shin J, McKee AC, Kowall NW, Kim J, Stein TD, Hwang D, Ryu H. Epigenome signatures landscaped by histone H3K9me3 are associated with the synaptic dysfunction in Alzheimer's disease. Aging Cell 2020; 19:e13153. [PMID: 32419307 PMCID: PMC7294781 DOI: 10.1111/acel.13153] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 02/09/2020] [Accepted: 03/29/2020] [Indexed: 01/03/2023] Open
Abstract
The pathogenesis of Alzheimer's disease (AD) and the commonest cause of dementia in the elderly remain incompletely understood. Recently, epigenetic modifications have been shown to play a potential role in neurodegeneration, but the specific involvement of epigenetic signatures landscaped by heterochromatin has not been studied in AD. Herein, we discovered that H3K9me3-mediated heterochromatin condensation is elevated in the cortex of sporadic AD postmortem brains. In order to identify which epigenomes are modulated by heterochromatin, we performed H3K9me3-chromatin immunoprecipitation (ChIP)-sequencing and mRNA-sequencing on postmortem brains from normal subjects and AD patients. The integrated analyses of genome-wide ChIP- and mRNA-sequencing data identified epigenomes that were highly occupied by H3K9me3 and inversely correlated with their mRNA expression levels in AD. Biological network analysis further revealed H3K9me3-landscaped epigenomes to be mainly involved in synaptic transmission, neuronal differentiation, and cell motility. Together, our data show that the abnormal heterochromatin remodeling by H3K9me3 leads to down-regulation of synaptic function-related genes, suggesting that the epigenetic alteration by H3K9me3 is associated with the synaptic pathology of sporadic AD.
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Affiliation(s)
| | - Junghee Lee
- Veteran's Affairs Boston Healthcare SystemBostonMAUSA,Department of NeurologyBoston University Alzheimer’s Disease CenterBoston University School of MedicineBostonMAUSA
| | - Seung Jae Hyeon
- Center for NeuromedicineBrain Science InstituteKorea Institute of Science and TechnologySeoulSouth Korea
| | - Hyesun Cho
- Genome Medicine Institute and Department of BiochemistrySeoul National University College of MedicineSeoulSouth Korea
| | - Yu Jin Hwang
- Center for NeuromedicineBrain Science InstituteKorea Institute of Science and TechnologySeoulSouth Korea
| | - Jong‐Yeon Shin
- Genome Medicine Institute and Department of BiochemistrySeoul National University College of MedicineSeoulSouth Korea
| | - Ann C. McKee
- Veteran's Affairs Boston Healthcare SystemBostonMAUSA,Department of NeurologyBoston University Alzheimer’s Disease CenterBoston University School of MedicineBostonMAUSA,Center for the Study of Traumatic EncephalopathyBoston University School of MedicineBostonMAUSA
| | - Neil W. Kowall
- Veteran's Affairs Boston Healthcare SystemBostonMAUSA,Department of NeurologyBoston University Alzheimer’s Disease CenterBoston University School of MedicineBostonMAUSA
| | - Jong‐Il Kim
- Genome Medicine Institute and Department of BiochemistrySeoul National University College of MedicineSeoulSouth Korea
| | - Thor D. Stein
- Veteran's Affairs Boston Healthcare SystemBostonMAUSA,Department of NeurologyBoston University Alzheimer’s Disease CenterBoston University School of MedicineBostonMAUSA
| | - Daehee Hwang
- Department of Biological SciencesSeoul National UniversitySeoulSouth Korea
| | - Hoon Ryu
- Veteran's Affairs Boston Healthcare SystemBostonMAUSA,Department of NeurologyBoston University Alzheimer’s Disease CenterBoston University School of MedicineBostonMAUSA,Center for NeuromedicineBrain Science InstituteKorea Institute of Science and TechnologySeoulSouth Korea
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17
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Imperador CHL, Bardella VB, Dos Anjos EHM, Rodrigues VLCC, Cabral-de-Mello DC, Mello MLS. Spatial Distribution of Heterochromatin Bodies in the Nuclei of Triatoma infestans (Klug). MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:567-574. [PMID: 32393416 DOI: 10.1017/s143192762000149x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Constitutive heterochromatin typically exhibits low gene density and is commonly found adjacent or close to the nuclear periphery, in contrast to transcriptionally active genes concentrated in the innermost nuclear region. In Triatoma infestans cells, conspicuous constitutive heterochromatin forms deeply stained structures named chromocenters. However, to the best of our knowledge, no information exists regarding whether these chromocenters acquire a precise topology in the cell nuclei or whether their 18S rDNA, which is important for ribosome function, faces the nuclear center preferentially. In this work, the spatial distribution of fluorescent Feulgen-stained chromocenters and the distribution of their 18S rDNA was analyzed in Malpighian tubule cells of T. infestans using confocal microscopy. The chromocenters were shown to be spatially positioned relatively close to the nuclear periphery, though not adjacent to it. The variable distance between the chromocenters and the nuclear periphery suggests mobility of these bodies within the cell nuclei. The distribution of 18S rDNA at the edge of the chromocenters was not found to face the nuclear interior exclusively. Because the genome regions containing 18S rDNA in the chromocenters also face the nuclear periphery, the proximity of the chromocenters to this nuclear region is not assumed to be associated with overall gene silencing.
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Affiliation(s)
- Carlos Henrique L Imperador
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), Rua Monteiro Lobato 255, 13083-862Campinas, SP, Brazil
| | - Vanessa B Bardella
- Department of Biology, Institute of Biosciences, State University of São Paulo (Unesp), Avenida 24-A, 1515, 13506-900Rio Claro, SP, Brazil
| | - Eli Heber M Dos Anjos
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), Rua Monteiro Lobato 255, 13083-862Campinas, SP, Brazil
| | - Vera L C C Rodrigues
- Superintendence for Control of Endemic Diseases (SUCEN), Rua Afonso Pessini, 86, 13845-206Mogi-Guaçu, SP, Brazil
| | - Diogo C Cabral-de-Mello
- Department of Biology, Institute of Biosciences, State University of São Paulo (Unesp), Avenida 24-A, 1515, 13506-900Rio Claro, SP, Brazil
| | - Maria Luiza S Mello
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (Unicamp), Rua Monteiro Lobato 255, 13083-862Campinas, SP, Brazil
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18
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Abstract
Expensive and time-consuming approaches of immunoelectron microscopy of biopsy tissues continues to serve as the gold-standard for diagnostic pathology. The recent development of the new approach of expansion microscopy (ExM) capable of fourfold lateral expansion of biological specimens for their morphological examination at approximately 70 nm lateral resolution using ordinary diffraction limited optical microscopy, is a major advancement in cellular imaging. Here we report (1) an optimized fixation protocol for retention of cellular morphology while obtaining optimal expansion, (2) an ExM procedure for up to eightfold lateral and over 500-fold volumetric expansion, (3) demonstrate that ExM is anisotropic or differential between tissues, cellular organelles and domains within organelles themselves, and (4) apply image analysis and machine learning (ML) approaches to precisely assess differentially expanded cellular structures. We refer to this enhanced ExM approach combined with ML as differential expansion microscopy (DiExM), applicable to profiling biological specimens at the nanometer scale. DiExM holds great promise for the precise, rapid and inexpensive diagnosis of disease from pathological specimen slides.
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19
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Zhang T, Zhang W, Liu L, Chen Y. Simultaneous detection of site-specific histone methylations and acetylation assisted by single template oriented molecularly imprinted polymers. Analyst 2020; 145:1376-1383. [DOI: 10.1039/c9an02360g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A targeted proteomics assay combining single template oriented MIPs with LC-MS/MS for the simultaneous quantification of histone post-translational modification.
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Affiliation(s)
- Tianqi Zhang
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Wen Zhang
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Liang Liu
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
| | - Yun Chen
- School of Pharmarcy, Nanjing Medical University
- Nanjing
- China
- State Key Laboratory of Reproductive Medicine
- China
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20
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Fišerová J, Maninová M, Sieger T, Uhlířová J, Šebestová L, Efenberková M, Čapek M, Fišer K, Hozák P. Nuclear pore protein TPR associates with lamin B1 and affects nuclear lamina organization and nuclear pore distribution. Cell Mol Life Sci 2019; 76:2199-2216. [PMID: 30762072 PMCID: PMC11105453 DOI: 10.1007/s00018-019-03037-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 01/22/2019] [Accepted: 02/01/2019] [Indexed: 10/27/2022]
Abstract
The organization of the nuclear periphery is crucial for many nuclear functions. Nuclear lamins form dense network at the nuclear periphery and play a substantial role in chromatin organization, transcription regulation and in organization of nuclear pore complexes (NPCs). Here, we show that TPR, the protein located preferentially within the nuclear baskets of NPCs, associates with lamin B1. The depletion of TPR affects the organization of lamin B1 but not lamin A/C within the nuclear lamina as shown by stimulated emission depletion microscopy. Finally, reduction of TPR affects the distribution of NPCs within the nuclear envelope and the effect can be reversed by simultaneous knock-down of lamin A/C or the overexpression of lamin B1. Our work suggests a novel role for the TPR at the nuclear periphery: the TPR contributes to the organization of the nuclear lamina and in cooperation with lamins guards the interphase assembly of nuclear pore complexes.
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Affiliation(s)
- Jindřiška Fišerová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic.
| | - Miloslava Maninová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
| | - Tomáš Sieger
- Department of Cybernetics, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic
| | - Jana Uhlířová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
| | - Lenka Šebestová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
| | - Michaela Efenberková
- Microscopy Centre-LM and EM, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
| | - Martin Čapek
- Microscopy Centre-LM and EM, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
| | - Karel Fišer
- CLIP Laboratories, Department of Paediatric Haematology and Oncology, Second Faculty of Medicine, Charles University and University Hospital Motol Prague, V Úvalu 84, 150 06, Prague, Czech Republic
| | - Pavel Hozák
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
- Microscopy Centre-LM and EM, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, 142 00, Prague, Czech Republic
- Division BIOCEV, Institute of Molecular Genetics CAS, v.v.i., Průmyslová 595, Vestec, 252 50, Prague, Czech Republic
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21
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Kim JE. Bookmarking by histone methylation ensures chromosomal integrity during mitosis. Arch Pharm Res 2019; 42:466-480. [PMID: 31020544 DOI: 10.1007/s12272-019-01156-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/19/2019] [Indexed: 12/22/2022]
Abstract
The cell cycle is an orchestrated process that replicates DNA and transmits genetic information to daughter cells. Cell cycle progression is governed by diverse histone modifications that control gene transcription in a timely fashion. Histone modifications also regulate cell cycle progression by marking specific chromatic regions. While many reviews have covered histone phosphorylation and acetylation as regulators of the cell cycle, little attention has been paid to the roles of histone methylation in the faithful progression of mitosis. Indeed, specific histone methylations occurring before, during, or after mitosis affect kinetochore assembly and chromosome condensation and segregation. In addition to timing, histone methylations specify the chromatin regions such as chromosome arms, pericentromere, and centromere. Therefore, spatiotemporal programming of histone methylations ensures epigenetic inheritance through mitosis. This review mainly discusses histone methylations and their relevance to mitotic progression.
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Affiliation(s)
- Ja-Eun Kim
- Department of Pharmacology, School of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea.
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22
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Cell Cycle Progression Regulates Biogenesis and Cellular Localization of Lipid Droplets. Mol Cell Biol 2019; 39:MCB.00374-18. [PMID: 30782775 PMCID: PMC6469922 DOI: 10.1128/mcb.00374-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 01/25/2019] [Indexed: 12/19/2022] Open
Abstract
Intracellular lipid accumulation has been associated with a poor prognosis in cancer. We have previously reported the involvement of lipid droplets in cell proliferation in colon cancer cells, suggesting a role for these organelles in cancer development. Intracellular lipid accumulation has been associated with a poor prognosis in cancer. We have previously reported the involvement of lipid droplets in cell proliferation in colon cancer cells, suggesting a role for these organelles in cancer development. In this study, we evaluate the role of lipid droplets in cell cycle regulation and cellular transformation. Cell cycle synchronization of NIH 3T3 cells revealed increased numbers and dispersed distribution of lipid droplets specifically during S phase. Also, the transformed cell lineage NIH 3T3-H-rasV12 showed an accumulation of both lipid droplets and PLIN2 protein above the levels in NIH 3T3 cells. PLIN2 gene overexpression, however, was not able to induce NIH 3T3 cell transformation, disproving the hypothesis that PLIN2 is an oncogene. Furthermore, positive PLIN2 staining was strongly associated with highly proliferative Ki-67-positive areas in human colon adenocarcinoma tissue samples. Taken together, these results indicate that cell cycle progression is associated with tight regulation of lipid droplets, a process that is altered in transformed cells, suggesting the existence of a mechanism that connects cell cycle progression and cell proliferation with lipid accumulation.
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23
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Wilson C, Krieg AJ. KDM4B: A Nail for Every Hammer? Genes (Basel) 2019; 10:E134. [PMID: 30759871 PMCID: PMC6410163 DOI: 10.3390/genes10020134] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 01/01/2023] Open
Abstract
Epigenetic changes are well-established contributors to cancer progression and normal developmental processes. The reversible modification of histones plays a central role in regulating the nuclear processes of gene transcription, DNA replication, and DNA repair. The KDM4 family of Jumonj domain histone demethylases specifically target di- and tri-methylated lysine 9 on histone H3 (H3K9me3), removing a modification central to defining heterochromatin and gene repression. KDM4 enzymes are generally over-expressed in cancers, making them compelling targets for study and therapeutic inhibition. One of these family members, KDM4B, is especially interesting due to its regulation by multiple cellular stimuli, including DNA damage, steroid hormones, and hypoxia. In this review, we discuss what is known about the regulation of KDM4B in response to the cellular environment, and how this context-dependent expression may be translated into specific biological consequences in cancer and reproductive biology.
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Affiliation(s)
- Cailin Wilson
- Department of Pathology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - Adam J Krieg
- Department of Obstetrics and Gynecology, Oregon Health and Science University, Portland, OR 97239, USA.
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Beaverton, OR 97006, USA.
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Alvarenga EM, Imperador CH, Bardella VB, Rodrigues VL, Mondin M, Cabral-de-Mello DC, Moraes AS, Mello MLS. Histone acetylation and methylation marks in chromatin of Panstrongylus megistus (Hemiptera, Reduviidae). Acta Histochem 2018; 120:572-577. [PMID: 30005894 DOI: 10.1016/j.acthis.2018.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 07/03/2018] [Accepted: 07/03/2018] [Indexed: 12/12/2022]
Abstract
Panstrongylus megistus, a potential vector of Chagas disease, currently occupies a wider geographic distribution in Brazil than Triatoma infestans, another member of the hemipteran Reduviidae family and a vector of the same disease. A small heterochromatic body (chromocenter) formed by the Y chromosome is evident in the somatic cells of P. megistus, differing in size and chromosome type contribution from the well-studied chromocenters present in T. infestans. While the overall distribution of histone epigenetic marks differ when comparing the heterochromatin and euchromatin territories in T. infestans, no similar data have been established for other hemipteran reduviids, including P. megistus. In the present work, histone acetylation and methylation marks were investigated in cells of Malpighian tubules of P. megistus 5th instar nymphs using immunocytochemical assays and compared to previously published data for T. infestans. Although similarities between these species were found regarding absence of acetylated H3K9, H4K8 and H4K16, and H3K9me and H3K9me2 in the chromocenter, presence of these marks in euchromatin, and presence of H3K9me3 in the chromocenter, no intimate association of acetylated H4K8 and 18S rDNA was revealed in the chromocenter of P. megistus. The elevated abundance of H3K9me2 marks at the nuclear periphery in P. megistus cells, differing from data for T. infestans, is suggested to reflect differences in the interaction of lamina-associated chromatin domains with the nuclear lamina, methyl-transferase modulation and/or association with the last DNA endoreplication step in 5th instar nymphs, which is a matter for further investigation.
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25
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Lee J, Hwang YJ, Kim Y, Lee MY, Hyeon SJ, Lee S, Kim DH, Jang SJ, Im H, Min SJ, Choo H, Pae AN, Kim DJ, Cho KS, Kowall NW, Ryu H. Remodeling of heterochromatin structure slows neuropathological progression and prolongs survival in an animal model of Huntington's disease. Acta Neuropathol 2017; 134:729-748. [PMID: 28593442 DOI: 10.1007/s00401-017-1732-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 01/01/2023]
Abstract
Huntington's disease (HD) is an autosomal-dominant inherited neurological disorder caused by expanded CAG repeats in exon 1 of the Huntingtin (HTT) gene. Altered histone modifications and epigenetic mechanisms are closely associated with HD suggesting that transcriptional repression may play a pathogenic role. Epigenetic compounds have significant therapeutic effects in cellular and animal models of HD, but they have not been successful in clinical trials. Herein, we report that dSETDB1/ESET, a histone methyltransferase (HMT), is a mediator of mutant HTT-induced degeneration in a fly HD model. We found that nogalamycin, an anthracycline antibiotic and a chromatin remodeling drug, reduces trimethylated histone H3K9 (H3K9me3) levels and pericentromeric heterochromatin condensation by reducing the expression of Setdb1/Eset. H3K9me3-specific ChIP-on-ChIP analysis identified that the H3K9me3-enriched epigenome signatures of multiple neuronal pathways including Egr1, Fos, Ezh1, and Arc are deregulated in HD transgenic (R6/2) mice. Nogalamycin modulated the expression of the H3K9me3-landscaped epigenome in medium spiny neurons and reduced mutant HTT nuclear inclusion formation. Moreover, nogalamycin slowed neuropathological progression, preserved motor function, and extended the life span of R6/2 mice. Together, our results indicate that modulation of SETDB1/ESET and H3K9me3-dependent heterochromatin plasticity is responsible for the neuroprotective effects of nogalamycin in HD and that small compounds targeting dysfunctional histone modification and epigenetic modification by SETDB1/ESET may be a rational therapeutic strategy in HD.
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26
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Poleshko A, Shah PP, Gupta M, Babu A, Morley MP, Manderfield LJ, Ifkovits JL, Calderon D, Aghajanian H, Sierra-Pagán JE, Sun Z, Wang Q, Li L, Dubois NC, Morrisey EE, Lazar MA, Smith CL, Epstein JA, Jain R. Genome-Nuclear Lamina Interactions Regulate Cardiac Stem Cell Lineage Restriction. Cell 2017; 171:573-587.e14. [PMID: 29033129 DOI: 10.1016/j.cell.2017.09.018] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 08/25/2017] [Accepted: 09/12/2017] [Indexed: 01/15/2023]
Abstract
Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery.
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Affiliation(s)
- Andrey Poleshko
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Parisha P Shah
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mudit Gupta
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Apoorva Babu
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael P Morley
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lauren J Manderfield
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jamie L Ifkovits
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Damelys Calderon
- Department of Cell, Developmental, and Regenerative Biology, Mindich Child Health and Development Institute, and Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Haig Aghajanian
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Javier E Sierra-Pagán
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zheng Sun
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qiaohong Wang
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Li Li
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicole C Dubois
- Department of Cell, Developmental, and Regenerative Biology, Mindich Child Health and Development Institute, and Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Edward E Morrisey
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell A Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and the Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cheryl L Smith
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jonathan A Epstein
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Rajan Jain
- Departments of Medicine and Cell and Developmental Biology, Institute for Regenerative Medicine, and the Penn Cardiovascular Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.
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Lungu C, Pinter S, Broche J, Rathert P, Jeltsch A. Modular fluorescence complementation sensors for live cell detection of epigenetic signals at endogenous genomic sites. Nat Commun 2017; 8:649. [PMID: 28935858 PMCID: PMC5608954 DOI: 10.1038/s41467-017-00457-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 06/30/2017] [Indexed: 12/23/2022] Open
Abstract
Investigation of the fundamental role of epigenetic processes requires methods for the locus-specific detection of epigenetic modifications in living cells. Here, we address this urgent demand by developing four modular fluorescence complementation-based epigenetic biosensors for live-cell microscopy applications. These tools combine engineered DNA-binding proteins with domains recognizing defined epigenetic marks, both fused to non-fluorescent fragments of a fluorescent protein. The presence of the epigenetic mark at the target DNA sequence leads to the reconstitution of a functional fluorophore. With this approach, we could for the first time directly detect DNA methylation and histone 3 lysine 9 trimethylation at endogenous genomic sites in live cells and follow dynamic changes in these marks upon drug treatment, induction of epigenetic enzymes and during the cell cycle. We anticipate that this versatile technology will improve our understanding of how specific epigenetic signatures are set, erased and maintained during embryonic development or disease onset.Tools for imaging epigenetic modifications can shed light on the regulation of epigenetic processes. Here, the authors present a fluorescence complementation approach for detection of DNA and histone methylation at endogenous genomic sites allowing following of dynamic changes of these marks by live-cell microscopy.
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Affiliation(s)
- Cristiana Lungu
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Sabine Pinter
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Julian Broche
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Philipp Rathert
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany
| | - Albert Jeltsch
- Department of Biochemistry, Institute of Biochemistry and Technical Biochemistry, Stuttgart University, Allmandring 31, 70569, Stuttgart, Germany.
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28
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Iyer DR, Rhind N. Replication fork slowing and stalling are distinct, checkpoint-independent consequences of replicating damaged DNA. PLoS Genet 2017; 13:e1006958. [PMID: 28806726 PMCID: PMC5570505 DOI: 10.1371/journal.pgen.1006958] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/24/2017] [Accepted: 08/04/2017] [Indexed: 11/30/2022] Open
Abstract
In response to DNA damage during S phase, cells slow DNA replication. This slowing is orchestrated by the intra-S checkpoint and involves inhibition of origin firing and reduction of replication fork speed. Slowing of replication allows for tolerance of DNA damage and suppresses genomic instability. Although the mechanisms of origin inhibition by the intra-S checkpoint are understood, major questions remain about how the checkpoint regulates replication forks: Does the checkpoint regulate the rate of fork progression? Does the checkpoint affect all forks, or only those encountering damage? Does the checkpoint facilitate the replication of polymerase-blocking lesions? To address these questions, we have analyzed the checkpoint in the fission yeast Schizosaccharomyces pombe using a single-molecule DNA combing assay, which allows us to unambiguously separate the contribution of origin and fork regulation towards replication slowing, and allows us to investigate the behavior of individual forks. Moreover, we have interrogated the role of forks interacting with individual sites of damage by using three damaging agents-MMS, 4NQO and bleomycin-that cause similar levels of replication slowing with very different frequency of DNA lesions. We find that the checkpoint slows replication by inhibiting origin firing, but not by decreasing fork rates. However, the checkpoint appears to facilitate replication of damaged templates, allowing forks to more quickly pass lesions. Finally, using a novel analytic approach, we rigorously identify fork stalling events in our combing data and show that they play a previously unappreciated role in shaping replication kinetics in response to DNA damage.
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Affiliation(s)
- Divya Ramalingam Iyer
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Nicholas Rhind
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
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29
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Fukuda K, Inoguchi Y, Ichiyanagi K, Ichiyanagi T, Go Y, Nagano M, Yanagawa Y, Takaesu N, Ohkawa Y, Imai H, Sasaki H. Evolution of the sperm methylome of primates is associated with retrotransposon insertions and genome instability. Hum Mol Genet 2017. [DOI: 10.1093/hmg/ddx236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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30
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Fišerová J, Efenberková M, Sieger T, Maninová M, Uhlířová J, Hozák P. Chromatin organization at the nuclear periphery as revealed by image analysis of structured illumination microscopy data. J Cell Sci 2017; 130:2066-2077. [PMID: 28476938 DOI: 10.1242/jcs.198424] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 05/02/2017] [Indexed: 12/28/2022] Open
Abstract
The nuclear periphery (NP) plays a substantial role in chromatin organization. Heterochromatin at the NP is interspersed with active chromatin surrounding nuclear pore complexes (NPCs); however, details of the peripheral chromatin organization are missing. To discern the distribution of epigenetic marks at the NP of HeLa nuclei, we used structured illumination microscopy combined with a new MATLAB software tool for automatic NP and NPC detection, measurements of fluorescent intensity and statistical analysis of measured data. Our results show that marks for both active and non-active chromatin associate differentially with NPCs. The incidence of heterochromatin marks, such as H3K27me2 and H3K9me2, was significantly lower around NPCs. In contrast, the presence of marks of active chromatin such as H3K4me2 was only decreased very slightly around the NPCs or not at all (H3K9Ac). Interestingly, the histone demethylases LSD1 (also known as KDM1A) and KDM2A were enriched within the NPCs, suggesting that there was a chromatin-modifying mechanism at the NPCs. Inhibition of transcription resulted in a larger drop in the distribution of H1, H3K9me2 and H3K23me2, which implies that transcription has a role in the organization of heterochromatin at the NP.
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Affiliation(s)
- Jindřiška Fišerová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, Prague 142 00, Czech Republic
| | - Michaela Efenberková
- Microscopy Centre - LM and EM, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, Prague 142 00, Czech Republic
| | - Tomáš Sieger
- Department of Cybernetics, Faculty of Electrical Engineering, Czech Technical University in Prague, Prague, 121 35, Czech Republic
| | - Miloslava Maninová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, Prague 142 00, Czech Republic
| | - Jana Uhlířová
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, Prague 142 00, Czech Republic
| | - Pavel Hozák
- Department of Biology of the Cell Nucleus, Institute of Molecular Genetics CAS, v.v.i., Vídeňská 1083, Prague 142 00, Czech Republic.,Division BIOCEV, Institute of Molecular Genetics CAS, v.v.i., Průmyslová 595, Vestec, Prague 252 50, Czech Republic
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31
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Deimling SJ, Olsen JB, Tropepe V. The expanding role of the Ehmt2/G9a complex in neurodevelopment. NEUROGENESIS 2017; 4:e1316888. [PMID: 28596979 DOI: 10.1080/23262133.2017.1316888] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/22/2017] [Accepted: 03/30/2017] [Indexed: 10/19/2022]
Abstract
Epigenetic regulators play a crucial role in neurodevelopment. One such epigenetic complex, Ehmt1/2 (G9a/GLP), is essential for repressing gene transcription by methylating H3K9 in a highly tissue- and temporal-specific manner. Recently, data has emerged suggesting that this complex plays additional roles in regulating the activity of numerous other non-histone proteins. While much is known about the downstream effects of Ehmt1/2 function, evidence is only beginning to come to light suggesting the control of Ehmt1/2 function may be, at least in part, due to context-dependent binding partners. Here we review emerging roles for the Ehmt1/2 complex suggesting that it may play a much larger role than previously recognized, and discuss binding partners that we and others have recently characterized which act to coordinate its activity during early neurodevelopment.
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Affiliation(s)
- Steven J Deimling
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Jonathan B Olsen
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Vincent Tropepe
- Department of Cell & Systems Biology, University of Toronto, Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada; Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Canada
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32
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Wu R, Wang Z, Zhang H, Gan H, Zhang Z. H3K9me3 demethylase Kdm4d facilitates the formation of pre-initiative complex and regulates DNA replication. Nucleic Acids Res 2017; 45:169-180. [PMID: 27679476 PMCID: PMC5224507 DOI: 10.1093/nar/gkw848] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 11/30/2022] Open
Abstract
DNA replication is tightly regulated to occur once and only once per cell cycle. How chromatin, the physiological substrate of DNA replication machinery, regulates DNA replication remains largely unknown. Here we show that histone H3 lysine 9 demethylase Kdm4d regulates DNA replication in eukaryotic cells. Depletion of Kdm4d results in defects in DNA replication, which can be rescued by the expression of H3K9M, a histone H3 mutant transgene that reverses the effect of Kdm4d on H3K9 methylation. Kdm4d interacts with replication proteins, and its recruitment to DNA replication origins depends on the two pre-replicative complex components (origin recognition complex [ORC] and minichromosome maintenance [MCM] complex). Depletion of Kdm4d impairs the recruitment of Cdc45, proliferating cell nuclear antigen (PCNA), and polymerase δ, but not ORC and MCM proteins. These results demonstrate a novel mechanism by which Kdm4d regulates DNA replication by reducing the H3K9me3 level to facilitate formation of pre-initiative complex.
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Affiliation(s)
- Rentian Wu
- Department of Biochemistry and Molecular Biology, Mayo Clinic Cancer Center, Mayo Clinic, Rochester, MN 55902, USA
| | - Zhiquan Wang
- Department of Biochemistry and Molecular Biology, Mayo Clinic Cancer Center, Mayo Clinic, Rochester, MN 55902, USA
| | - Honglian Zhang
- Institute for Cancer Genetics, Department of Pediatric and Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Haiyun Gan
- Institute for Cancer Genetics, Department of Pediatric and Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Zhiguo Zhang
- Institute for Cancer Genetics, Department of Pediatric and Department of Genetics and Development, Columbia University, New York, NY 10032, USA
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33
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Alvarenga EM, Rodrigues VL, Moraes AS, Naves LS, Mondin M, Felisbino MB, Mello MLS. Histone epigenetic marks in heterochromatin and euchromatin of the Chagas' disease vector, Triatoma infestans. Acta Histochem 2016; 118:401-12. [PMID: 27079857 DOI: 10.1016/j.acthis.2016.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 03/31/2016] [Accepted: 04/05/2016] [Indexed: 01/23/2023]
Abstract
Triatoma infestans, a vector of Chagas' disease, shows several particular cell biology characteristics, including the presence of conspicuous heterochromatic bodies (chromocenters) where DNA methylation has not been previously detected. Whether histone modifications contribute to the condensed state of these bodies has not yet been studied. Here, we investigated epigenetic modifications of histones H3 and H4 and presence of the non-histone heterochromatin protein (HP1-α) in the chromocenters and euchromatin of T. infestans cell nuclei, using immunocytochemistry. The effect of different concentrations of the histone deacetylase inhibitors valproic acid (VPA) and sodium butyrate (NaBt) on chromocenter condensation was visually examined; in VPA-treated specimens, this effect was also analyzed by image analysis. Trimethylated H3K9 signals, which were revealed in chromocenter and non-chromocenter areas, were strongest in chromocenters, whereas selected acetylated histone marks and mono- and dimethylated H3K9 and H4K20 signals were detected only in euchromatin. Weak trimethylated H4K20 signals and variable distribution of HP1-α were detected in chromocenters of part of the cellular population analyzed. Although specific VPA and NaBt treatment conditions affected the heterochromatin condensation pattern, they did not induce a decrease in survival and molting rates of the T. infestans nymphs. The VPA-induced chromatin remodeling was not accompanied by induction of H3K9 acetylation in chromocenters. Present findings regarding histone modifications and effects following VPA or NaBt treatments did not yet solve the question of which factors are responsible for maintenance of the condensed state of chromocenters in T. infestans. A possibility requiring further investigation remains on histone methylation marks and/or non-histone proteins.
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Pinter SF. A Tale of Two Cities: How Xist and its partners localize to and silence the bicompartmental X. Semin Cell Dev Biol 2016; 56:19-34. [PMID: 27072488 DOI: 10.1016/j.semcdb.2016.03.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 03/30/2016] [Accepted: 03/30/2016] [Indexed: 10/22/2022]
Abstract
Sex chromosomal dosage compensation in mammals takes the form of X chromosome inactivation (XCI), driven by the non-coding RNA Xist. In contrast to dosage compensation systems of flies and worms, mammalian XCI has to restrict its function to the Xist-producing X chromosome, while leaving autosomes and active X untouched. The mechanisms behind the long-range yet cis-specific localization and silencing activities of Xist have long been enigmatic, but genomics, proteomics, super-resolution microscopy, and innovative genetic approaches have produced significant new insights in recent years. In this review, I summarize and integrate these findings with a particular focus on the redundant yet mutually reinforcing pathways that enable long-term transcriptional repression throughout the soma. This includes an exploration of concurrent epigenetic changes acting in parallel within two distinct compartments of the inactive X. I also examine how Polycomb repressive complexes 1 and 2 and macroH2A may bridge XCI establishment and maintenance. XCI is a remarkable phenomenon that operates across multiple scales, combining changes in nuclear architecture, chromosome topology, chromatin compaction, and nucleosome/nucleotide-level epigenetic cues. Learning how these pathways act in concert likely holds the answer to the riddle posed by Cattanach's and other autosomal translocations: What makes the X especially receptive to XCI?
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Affiliation(s)
- Stefan F Pinter
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030-6403, USA.
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35
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Felisbino MB, Alves da Costa T, Gatti MSV, Mello MLS. Differential Response of Human Hepatocyte Chromatin to HDAC Inhibitors as a Function of Microenvironmental Glucose Level. J Cell Physiol 2016; 231:2257-65. [DOI: 10.1002/jcp.25343] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/12/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Marina Barreto Felisbino
- Department of Structural and Functional Biology, Institute of Biology; University of Campinas (Unicamp); Campinas São Paulo Brazil
| | - Thiago Alves da Costa
- Department of Structural and Functional Biology, Institute of Biology; University of Campinas (Unicamp); Campinas São Paulo Brazil
| | - Maria Silvia Viccari Gatti
- Department of Genetics, Evolution and Bioagents, Institute of Biology; University of Campinas (Unicamp); Campinas São Paulo Brazil
| | - Maria Luiza Silveira Mello
- Department of Structural and Functional Biology, Institute of Biology; University of Campinas (Unicamp); Campinas São Paulo Brazil
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36
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Lund EG, Duband-Goulet I, Oldenburg A, Buendia B, Collas P. Distinct features of lamin A-interacting chromatin domains mapped by ChIP-sequencing from sonicated or micrococcal nuclease-digested chromatin. Nucleus 2015; 6:30-9. [PMID: 25602132 DOI: 10.4161/19491034.2014.990855] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The nuclear lamina has been shown to interact with the genome through lamina-associated domains (LADs). LADs have been identified by DamID, a proximity labeling assay, and more recently by chromatin immunoprecipitation-sequencing (ChIP-seq) of A- and B-type lamins. LADs form megabase-size domains at the nuclear periphery, they are gene-poor and mostly heterochromatic. Here, we show that the mode of chromatin fragmentation for ChIP, namely bath sonication or digestion with micrococcal nuclease (MNase), leads to the discovery of common but also distinct sets of lamin-interacting domains, or LiDs. Using ChIP-seq, we show the existence of lamin A/C (LMNA) LiDs with distinct gene contents, histone composition enrichment and relationships to lamin B1-interacting domains. The extent of genome coverage of lamin A/C (LMNA) LiDs in sonicated or MNase-digested chromatin is similar (∼730 megabases); however over half of these domains are uniquely detected in sonicated or MNase-digested chromatin. Sonication-specific LMNA LiDs are gene-poor and devoid of a broad panel of histone modifications, while MNase-specific LMNA LiDs are of higher gene density and are enriched in H3K9me3, H3K27me3 and in histone variant H2A.Z. LMNB1 LiDs are gene-poor and show no or little enrichment in these marks. Comparison of published LMNB1 DamID LADs with LMNB1 and LMNA LiDs identified here by ChIP-seq further shows that LMNA can associate with 'open' chromatin domains displaying euchromatin characteristics, and which are not associated with LMNB1. The differential genomic and epigenetic properties of lamin-interacting domains reflect the existence of distinct LiD populations identifiable in different chromatin contexts, including nuclease-accessible regions presumably localized in the nuclear interior.
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Affiliation(s)
- Eivind G Lund
- a Department of Molecular Medicine, Institute of Basic Medical Sciences ; University of Oslo, and Norwegian Center for Stem Cell Research , Oslo , Norway
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Mishima Y, Jayasinghe CD, Lu K, Otani J, Shirakawa M, Kawakami T, Kimura H, Hojo H, Carlton P, Tajima S, Suetake I. Nucleosome compaction facilitates HP1γ binding to methylated H3K9. Nucleic Acids Res 2015; 43:10200-12. [PMID: 26319017 PMCID: PMC4666388 DOI: 10.1093/nar/gkv841] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 08/07/2015] [Indexed: 12/15/2022] Open
Abstract
The α, β and γ isoforms of mammalian heterochromatin protein 1 (HP1) selectively bind to methylated lysine 9 of histone H3 via their chromodomains. Although the phenotypes of HP1-knockout mice are distinct for each isoform, the molecular mechanisms underlying HP1 isoform-specific function remain elusive. In the present study, we found that in contrast to HP1α, HP1γ could not bind tri-methylated H3 lysine 9 in a reconstituted tetra-nucleosomes when the nucleosomes were in an uncompacted state. The hinge region connecting HP1's chromodomain and chromoshadow domain contributed to the distinct recognition of the nucleosomes by HP1α and HP1γ. HP1γ, but not HP1α, was strongly enhanced in selective binding to tri-methylated lysine 9 in histone H3 by the addition of Mg(2+) or linker histone H1, which are known to induce compaction of nucleosomes. We propose that this novel property of HP1γ recognition of lysine 9 in the histone H3 tail in different nucleosome structures plays a role in reading the histone code.
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Affiliation(s)
- Yuichi Mishima
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Chanika D Jayasinghe
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Kai Lu
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Junji Otani
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Masahiro Shirakawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Toru Kawakami
- Laboratory of Organic Chemistry, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Hironobu Kimura
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hironobu Hojo
- Laboratory of Organic Chemistry, Institute for Protein Research, Osaka University, Osaka 565-0871, Japan
| | - Peter Carlton
- Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Shoji Tajima
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Isao Suetake
- Laboratory of Epigenetics, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan CREST, Japan Science and Technology Agency, Saitama 332-0012, Japan
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Giri S, Aggarwal V, Pontis J, Shen Z, Chakraborty A, Khan A, Mizzen C, Prasanth KV, Ait-Si-Ali S, Ha T, Prasanth SG. The preRC protein ORCA organizes heterochromatin by assembling histone H3 lysine 9 methyltransferases on chromatin. eLife 2015; 4. [PMID: 25922909 PMCID: PMC4442312 DOI: 10.7554/elife.06496] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/27/2015] [Indexed: 12/20/2022] Open
Abstract
Heterochromatic domains are enriched with repressive histone marks, including histone H3 lysine 9 methylation, written by lysine methyltransferases (KMTs). The pre-replication complex protein, origin recognition complex-associated (ORCA/LRWD1), preferentially localizes to heterochromatic regions in post-replicated cells. Its role in heterochromatin organization remained elusive. ORCA recognizes methylated H3K9 marks and interacts with repressive KMTs, including G9a/GLP and Suv39H1 in a chromatin context-dependent manner. Single-molecule pull-down assays demonstrate that ORCA-ORC (Origin Recognition Complex) and multiple H3K9 KMTs exist in a single complex and that ORCA stabilizes H3K9 KMT complex. Cells lacking ORCA show alterations in chromatin architecture, with significantly reduced H3K9 di- and tri-methylation at specific chromatin sites. Changes in heterochromatin structure due to loss of ORCA affect replication timing, preferentially at the late-replicating regions. We demonstrate that ORCA acts as a scaffold for the establishment of H3K9 KMT complex and its association and activity at specific chromatin sites is crucial for the organization of heterochromatin structure. DOI:http://dx.doi.org/10.7554/eLife.06496.001 The genetic material inside cells is contained within molecules of DNA. In animals and other eukaryotes, the DNA is tightly wrapped around proteins called histones to form a compact structure known as chromatin. There are two forms of chromatin: loosely packed chromatin tends to contain genes that are highly active in cells, while tightly packed chromatin—called heterochromatin—tends to contain less-active genes. How tightly DNA is packed in chromatin can be changed by adding small molecules known as methyl tags to individual histone proteins. Enzymes called KMTs are responsible for attaching these methyl tags to a specific site on the histones. Before a cell divides, it duplicates its DNA and these methyl tags, so that they can be passed onto the newly formed cells. This enables the new cells to ‘remember’ which genes were inactive or active in the original cell. A protein known as ORCA associates with heterochromatin, but it is not clear what role it plays in controlling the structure of chromatin. Giri et al. studied ORCA and the KMTs in human cells. The experiments show that ORCA recognizes the methyl tags and binds to the KMTs in regions of heterochromatin, but not in regions where the DNA is more loosely packed. Next, Giri et al. used a technique called single-molecule pull-down, which is able to identify individual proteins within a group. These experiments showed that several KMT enzymes can bind to a single ORCA protein at the same time. ORCA stabilizes the binding of KMTs to chromatin, which enables the KMTs to modify the histones within it. Cells lacking ORCA had fewer methyl tags on their histones, which altered the structure of the chromatin. This also affected the timing with which DNA copying takes place in cells before the cell divides. Giri et al.'s findings suggest that ORCA acts as a scaffold for the KMTs and that its activity at specific sites on chromatin is important for the organization of heterochromatin. The next step is to identify the exact regions in the genome where the timing of DNA copying is regulated by ORCA. DOI:http://dx.doi.org/10.7554/eLife.06496.002
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Affiliation(s)
- Sumanprava Giri
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Vasudha Aggarwal
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Julien Pontis
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Epigénétique et Destin Cellulaire, UMR7216, Centre National de la Recherche Scientifique, Paris, France
| | - Zhen Shen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Arindam Chakraborty
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Abid Khan
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Craig Mizzen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Kannanganattu V Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Slimane Ait-Si-Ali
- Université Paris Diderot, Sorbonne Paris Cité, Laboratoire Epigénétique et Destin Cellulaire, UMR7216, Centre National de la Recherche Scientifique, Paris, France
| | - Taekjip Ha
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Champaign, United States
| | - Supriya G Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Champaign, United States
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Talamas JA, Capelson M. Nuclear envelope and genome interactions in cell fate. Front Genet 2015; 6:95. [PMID: 25852741 PMCID: PMC4365743 DOI: 10.3389/fgene.2015.00095] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/22/2015] [Indexed: 12/14/2022] Open
Abstract
The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate.
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Affiliation(s)
- Jessica A Talamas
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Maya Capelson
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
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40
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Gavrilov AA, Razin SV. Compartmentalization of the cell nucleus and spatial organization of the genome. Mol Biol 2015. [DOI: 10.1134/s0026893315010033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Ulianov SV, Gavrilov AA, Razin SV. Nuclear Compartments, Genome Folding, and Enhancer-Promoter Communication. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 315:183-244. [DOI: 10.1016/bs.ircmb.2014.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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42
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Cowell IG, Papageorgiou N, Padget K, Watters GP, Austin CA. Histone deacetylase inhibition redistributes topoisomerase IIb from heterochromatin to euchromatin. Nucleus 2014. [DOI: 10.4161/nucl.14194] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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43
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K MJ, Laxmi A. DUF581 is plant specific FCS-like zinc finger involved in protein-protein interaction. PLoS One 2014; 9:e99074. [PMID: 24901469 PMCID: PMC4047054 DOI: 10.1371/journal.pone.0099074] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 05/11/2014] [Indexed: 11/18/2022] Open
Abstract
Zinc fingers are a ubiquitous class of protein domain with considerable variation in structure and function. Zf-FCS is a highly diverged group of C2-C2 zinc finger which is present in animals, prokaryotes and viruses, but not in plants. In this study we identified that a plant specific domain of unknown function, DUF581 is a zf-FCS type zinc finger. Based on HMM-HMM comparison and signature motif similarity we named this domain as FCS-Like Zinc finger (FLZ) domain. A genome wide survey identified that FLZ domain containing genes are bryophytic in origin and this gene family is expanded in spermatophytes. Expression analysis of selected FLZ gene family members of A. thaliana identified an overlapping expression pattern suggesting a possible redundancy in their function. Unlike the zf-FCS domain, the FLZ domain found to be highly conserved in sequence and structure. Using a combination of bioinformatic and protein-protein interaction tools, we identified that FLZ domain is involved in protein-protein interaction.
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Affiliation(s)
| | - Ashverya Laxmi
- National Institute of Plant Genome Research, New Delhi, India
- * E-mail:
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44
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Shaiken TE, Opekun AR. Dissecting the cell to nucleus, perinucleus and cytosol. Sci Rep 2014; 4:4923. [PMID: 24815916 PMCID: PMC4017230 DOI: 10.1038/srep04923] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 04/22/2014] [Indexed: 12/25/2022] Open
Abstract
Cells have been described under the microscope as organelles containing cytoplasm and the nucleus. However, an unnoted structure exists between the cytoplasm and the nucleoplasm of eukaryotic cells. In addition to the nuclear envelope, there exists a perinuclear region (PNR or perinucleus) with unknown composition and function. Until now, an investigation of the role of the perinucleus has been restricted by the absence of a PNR isolation method. This manuscript describes a perinucleus isolation technique on the basis of its unique compact organization. The perinucleus was found to contain approximately 15 to 18% of the total proteins of the mammalian cell, almost half of the proteins of nuclei. Using four different normal and cancer cell lines, it was shown that the composition of PNR is highly dynamic. Application of the method showed that translocation of the p53 tumor-suppressor protein to the perinucleus in immortalized MEF cells is correlated with the translocation of p53-stabilizing protein, nucleophosmin (B23), to the PNR. Herein, the concept of the perinuclear region is advanced as a formal, identifiable structure. The roles of the perinucleus in maintaining genome integrity, regulation of gene expression and understanding of malignant transformation are discussed.
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Affiliation(s)
- Tattym E Shaiken
- Department of Molecular and Cellular Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Antone R Opekun
- Departments of Medicine & Pediatrics G.I. & S.A.H.S. Baylor College of Medicine-McNair Faculty Center A10.019 One Baylor Plaza (GI Medicine MS901), Houston, Texas 77030, USA
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45
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Etienne O, Bery A, Roque T, Desmaze C, Boussin FD. Assessing cell cycle progression of neural stem and progenitor cells in the mouse developing brain after genotoxic stress. J Vis Exp 2014. [PMID: 24837791 DOI: 10.3791/51209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Neurons of the cerebral cortex are generated during brain development from different types of neural stem and progenitor cells (NSPC), which form a pseudostratified epithelium lining the lateral ventricles of the embryonic brain. Genotoxic stresses, such as ionizing radiation, have highly deleterious effects on the developing brain related to the high sensitivity of NSPC. Elucidation of the cellular and molecular mechanisms involved depends on the characterization of the DNA damage response of these particular types of cells, which requires an accurate method to determine NSPC progression through the cell cycle in the damaged tissue. Here is shown a method based on successive intraperitoneal injections of EdU and BrdU in pregnant mice and further detection of these two thymidine analogues in coronal sections of the embryonic brain. EdU and BrdU are both incorporated in DNA of replicating cells during S phase and are detected by two different techniques (azide or a specific antibody, respectively), which facilitate their simultaneous detection. EdU and BrdU staining are then determined for each NSPC nucleus in function of its distance from the ventricular margin in a standard region of the dorsal telencephalon. Thus this dual labeling technique allows distinguishing cells that progressed through the cell cycle from those that have activated a cell cycle checkpoint leading to cell cycle arrest in response to DNA damage. An example of experiment is presented, in which EdU was injected before irradiation and BrdU immediately after and analyzes performed within the 4 hr following irradiation. This protocol provides an accurate analysis of the acute DNA damage response of NSPC in function of the phase of the cell cycle at which they have been irradiated. This method is easily transposable to many other systems in order to determine the impact of a particular treatment on cell cycle progression in living tissues.
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Affiliation(s)
- Olivier Etienne
- Laboratoire de Radiopathologie, CEA DSV iRCM SCSR; INSERM, U967; Université Paris Diderot, Sorbonne Paris Cité; Université Paris Sud, UMR 967
| | - Amandine Bery
- Laboratoire de Radiopathologie, CEA DSV iRCM SCSR; INSERM, U967; Université Paris Diderot, Sorbonne Paris Cité; Université Paris Sud, UMR 967
| | - Telma Roque
- Laboratoire de Radiopathologie, CEA DSV iRCM SCSR; INSERM, U967; Université Paris Diderot, Sorbonne Paris Cité; Université Paris Sud, UMR 967
| | - Chantal Desmaze
- Laboratoire de Radiopathologie, CEA DSV iRCM SCSR; INSERM, U967; Université Paris Diderot, Sorbonne Paris Cité; Université Paris Sud, UMR 967
| | - François D Boussin
- Laboratoire de Radiopathologie, CEA DSV iRCM SCSR; INSERM, U967; Université Paris Diderot, Sorbonne Paris Cité; Université Paris Sud, UMR 967;
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46
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Ragoczy T, Telling A, Scalzo D, Kooperberg C, Groudine M. Functional redundancy in the nuclear compartmentalization of the late-replicating genome. Nucleus 2014; 5:626-35. [PMID: 25493640 PMCID: PMC4615584 DOI: 10.4161/19491034.2014.990863] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 10/15/2014] [Accepted: 10/24/2014] [Indexed: 12/14/2022] Open
Abstract
The eukaryotic nucleus is structurally and functionally organized, as reflected in the distribution of its protein and DNA components. The genome itself is segregated into euchromatin and heterochromatin that replicate in a distinct spatio-temporal manner. We used a combination of fluorescence in situ hybridization (FISH) and DamID to investigate the localization of the early and late replicating components of the genome in a lymphoblastoid cell background. Our analyses revealed that the bulk of late replicating chromatin localizes to the nuclear peripheral heterochromatin (PH) in a chromosome size and gene density dependent manner. Late replicating DNA on small chromosomes exhibits a much lower tendency to localize to PH and tends to associate with alternate repressive subcompartments such as pericentromeric (PCH) and perinucleolar heterochromatin (PNH). Furthermore, multicolor FISH analysis revealed that late replicating loci, particularly on the smaller chromosomes, may associate with any of these 3 repressive subcompartments, including more than one at the same time. These results suggest a functional equivalence or redundancy among the 3 subcompartments. Consistent with this notion, disruption of nucleoli resulted in an increased association of late replicating loci with peripheral heterochromatin. Our analysis reveals that rather than considering the morphologically distinct PH, PCH and PNH as individual subcompartments, they should be considered in aggregate as a functional compartment for late replicating chromatin.
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Key Words
- Chr, chromosome
- DamID
- DamID, Dam identification
- EU, 5-Ethynyl uridine
- FISH, fluorescence in situ hybridization
- LAD, lamina associated domain
- NOR, nucleolar organizing region
- PCH, pericentromeric heterochromatin
- PH, peripheral heterochromatin
- PNH, perinucleolar heterochromatin
- heterochromatin
- localization
- nuclear organization
- nuclear periphery, pericentromeric heterochromatin
- perinucleolar heterochromatin
- replication timing
- repressive compartments
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Affiliation(s)
- Tobias Ragoczy
- Division of Basic Sciences; Fred Hutchinson Cancer Research Center; Seattle, WA USA
| | - Agnes Telling
- Division of Basic Sciences; Fred Hutchinson Cancer Research Center; Seattle, WA USA
| | - David Scalzo
- Division of Basic Sciences; Fred Hutchinson Cancer Research Center; Seattle, WA USA
| | - Charles Kooperberg
- Division of Public Health Sciences; Fred Hutchinson Cancer Research Center; Seattle, WA USA
| | - Mark Groudine
- Division of Basic Sciences; Fred Hutchinson Cancer Research Center; Seattle, WA USA
- Department of Radiation Oncology; University of Washington School of Medicine; Seattle, WA USA
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47
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Bian Q, Khanna N, Alvikas J, Belmont AS. β-Globin cis-elements determine differential nuclear targeting through epigenetic modifications. ACTA ACUST UNITED AC 2013; 203:767-83. [PMID: 24297746 PMCID: PMC3857487 DOI: 10.1083/jcb.201305027] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Multiple cis-elements surrounding the β-globin gene locus combine to target this locus to the nuclear periphery through at least two different epigenetic marks. Increasing evidence points to nuclear compartmentalization as a contributing mechanism for gene regulation, yet mechanisms for compartmentalization remain unclear. In this paper, we use autonomous targeting of bacterial artificial chromosome (BAC) transgenes to reveal cis requirements for peripheral targeting. Three peripheral targeting regions (PTRs) within an HBB BAC bias a competition between pericentric versus peripheral heterochromatin targeting toward the nuclear periphery, which correlates with increased H3K9me3 across the β-globin gene cluster and locus control region. Targeting to both heterochromatin compartments is dependent on Suv39H-mediated H3K9me3 methylation. In different chromosomal contexts, PTRs confer no targeting, targeting to pericentric heterochromatin, or targeting to the periphery. A combination of fluorescent in situ hybridization, BAC transgenesis, and knockdown experiments reveals that peripheral tethering of the endogenous HBB locus depends both on Suv39H-mediated H3K9me3 methylation over hundreds of kilobases surrounding HBB and on G9a-mediated H3K9me2 methylation over flanking sequences in an adjacent lamin-associated domain. Our results demonstrate that multiple cis-elements regulate the overall balance of specific epigenetic marks and peripheral gene targeting.
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Affiliation(s)
- Qian Bian
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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48
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Hwang YJ, Han D, Kim KY, Min SJ, Kowall NW, Yang L, Lee J, Kim Y, Ryu H. ESET methylates UBF at K232/254 and regulates nucleolar heterochromatin plasticity and rDNA transcription. Nucleic Acids Res 2013; 42:1628-43. [PMID: 24234436 PMCID: PMC3919562 DOI: 10.1093/nar/gkt1041] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The remodeling of chromatin in the nucleolus is important for the control of ribosomal DNA (rDNA) transcription and ribosome biogenesis. Herein, we found that upstream binding factor (UBF) interacts with ESET, a histone H3K9 methyltransferase and is trimethylated at Lys (K) 232/254 by ESET. UBF trimethylation leads to nucleolar chromatin condensation and decreased rDNA transcriptional activity. UBF mutations at K232/254A and K232/254R restored rDNA transcriptional activity in response to ESET. Both ESET-ΔSET mutant and knockdown of ESET by short hairpin RNA reduced trimethylation of UBF and resulted in the restoration of rDNA transcription. Atomic force microscopy confirmed that UBF trimethylated by ESET modulates the plasticity of nucleolar chromatin. We further demonstrated that UBF trimethylation at K232/254 by ESET deregulates rDNA transcription in a cell model of Huntington’s disease. Together, our findings show that a novel epigenetic modification of UBF is linked to impaired rDNA transcription and nucleolar chromatin remodeling, which may play key roles in the pathogenesis of neurodegeneration.
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Affiliation(s)
- Yu Jin Hwang
- Department of Biomedical Sciences, World Class University Neurocytomics Group, Seoul National University College of Medicine, Seoul 110-799, South Korea, Medical Engineering, Seoul National University College of Medicine, Seoul 110-799, South Korea, Center for Neuro-Medicine, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 136-791, South Korea, VA Boston Healthcare System, Boston, MA 02130, USA, Boston University Alzheimer's Disease Center and Department of Neurology, Boston University School of Medicine, Boston, MA 02118, USA, Department of Orthopedics and Division of Hematology, University of Washington School of Medicine, Seattle, WA 98195, USA and Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108, USA
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49
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Ontoso D, Kauppi L, Keeney S, San-Segundo PA. Dynamics of DOT1L localization and H3K79 methylation during meiotic prophase I in mouse spermatocytes. Chromosoma 2013; 123:147-64. [PMID: 24105599 DOI: 10.1007/s00412-013-0438-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/06/2013] [Accepted: 09/24/2013] [Indexed: 02/04/2023]
Abstract
During meiotic prophase I, interactions between maternal and paternal chromosomes, under checkpoint surveillance, establish connections between homologs that promote their accurate distribution to meiotic progeny. In human, faulty meiosis causes aneuploidy resulting in miscarriages and genetic diseases. Meiotic processes occur in the context of chromatin; therefore, histone post-translational modifications are expected to play important roles. Here, we report the cytological distribution of the evolutionarily conserved DOT1L methyltransferase and the different H3K79 methylation states resulting from its activity (mono-, di- and tri-methylation; H3K79me1, me2 and me3, respectively) during meiotic prophase I in mouse spermatocytes. In the wild type, whereas low amounts of H3K79me1 are rather uniformly present throughout prophase I, levels of DOT1L, H3K79me2 and H3K79me3 exhibit a notable increase from pachynema onwards, but with differential subnuclear distribution patterns. The heterochromatic centromeric regions and the sex body are enriched for H3K79me3. In contrast, H3K79me2 is present all over the chromatin, but is largely excluded from the sex body despite the accumulation of DOT1L. In meiosis-defective mouse mutants, the increase of DOT1L and H3K79me is blocked at the same stage where meiosis is arrested. H3K79me patterns, combined with the cytological analysis of the H3.3, γH2AX, macroH2A and H2A.Z histone variants, are consistent with a differential role for these epigenetic marks in male mouse meiotic prophase I. We propose that H3K79me2 is related to transcriptional reactivation on autosomes during pachynema, whereas H3K79me3 may contribute to the maintenance of repressive chromatin at centromeric regions and the sex body.
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Affiliation(s)
- David Ontoso
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas and University of Salamanca, 37007, Salamanca, Spain
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Lee J, Hwang YJ, Kim KY, Kowall NW, Ryu H. Epigenetic mechanisms of neurodegeneration in Huntington's disease. Neurotherapeutics 2013; 10:664-76. [PMID: 24006238 PMCID: PMC3805871 DOI: 10.1007/s13311-013-0206-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Huntington's disease (HD) is an incurable and fatal hereditary neurodegenerative disorder of mid-life onset characterized by chorea, emotional distress, and progressive cognitive decline. HD is caused by an expansion of CAG repeats coding for glutamine (Q) in exon 1 of the huntingtin gene. Recent studies suggest that epigenetic modifications may play a key role in HD pathogenesis. Alterations of the epigenetic "histone code" lead to chromatin remodeling and deregulation of neuronal gene transcription that are prominently linked to HD pathogenesis. Furthermore, specific noncoding RNAs and microRNAs are associated with neuronal damage in HD. In this review, we discuss how DNA methylation, post-translational modifications of histone, and noncoding RNA function are affected and involved in HD pathogenesis. In addition, we summarize the therapeutic effects of histone deacetylase inhibitors and DNA binding drugs on epigenetic modifications and neuropathological sequelae in HD. Our understanding of the role of these epigenetic mechanisms may lead to the identification of novel biological markers and new therapeutic targets to treat HD.
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Affiliation(s)
- Junghee Lee
- />Boston University Alzheimer’s Disease Center and Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
- />VA Boston Healthcare System, Boston, MA 02130 USA
| | - Yu Jin Hwang
- />WCU Neurocytomics Group, Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, 110-799 South Korea
| | - Ki Yoon Kim
- />WCU Neurocytomics Group, Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, 110-799 South Korea
| | - Neil W. Kowall
- />Boston University Alzheimer’s Disease Center and Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
- />VA Boston Healthcare System, Boston, MA 02130 USA
| | - Hoon Ryu
- />Boston University Alzheimer’s Disease Center and Department of Neurology, Boston University School of Medicine, Boston, MA 02118 USA
- />VA Boston Healthcare System, Boston, MA 02130 USA
- />WCU Neurocytomics Group, Department of Biomedical Sciences, Seoul National University Graduate School, Seoul, 110-799 South Korea
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