1
|
Siegler BH, Thon JN, Altvater M, Schenz J, Larmann J, Weigand MA, Weiterer S. Abdominal surgery induces long-lasting changes in expression and binding of CTCF with impact on Major Histocompatibility Complex II transcription in circulating human monocytes. PLoS One 2023; 18:e0293347. [PMID: 37878653 PMCID: PMC10599505 DOI: 10.1371/journal.pone.0293347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 10/11/2023] [Indexed: 10/27/2023] Open
Abstract
BACKGROUND Postoperative immunosuppression has been recognized as an important driver of surgery-related morbidity and mortality. It is characterized by lymphocyte depression and impaired monocyte capability to present foreign antigens to T-cells via Major Histocompatibility Complex, Class II (MHC-II) molecules. In patients with postoperative abdominal sepsis, we previously detected a persisting differential binding of the CCCTC-Binding Factor (CTCF), a superordinate regulator of transcription, inside the MHC-II region with specific impact on human leucocyte antigen (HLA) gene expression. In this prospective exploratory study, we investigated to which extent major surgery affects the MHC-II region of circulating CD14+-monocytes. RESULTS In non-immunocompromised patients undergoing elective major abdominal surgery, a postoperative loss of monocyte HLA-DR surface receptor density was accompanied by a decline in the transcription levels of the classical MHC-II genes HLA-DRA, HLA-DRB1, HLA-DPA1 and HLA-DPB1. The surgical event decreased the expression of the transcriptional MHC-II regulators CIITA and CTCF and led to a lower CTCF enrichment at an intergenic sequence within the HLA-DR subregion. During the observation period, we found a slow and only incomplete restoration of monocyte HLA-DR surface receptor density as well as a partial recovery of CIITA, HLA-DRA and HLA-DRB1 expression. In contrast, transcription of HLA-DPA1, HLA-DPB1, CTCF and binding of CTCF within the MHC-II remained altered. CONCLUSION In circulating monocytes, major surgery does not globally affect MHC-II transcription but rather induces specific changes in the expression of selected HLA genes, followed by differential recovery patterns and accompanied by a prolonged reduction of CTCF expression and binding within the MHC-II region. Our results hint toward a long-lasting impact of a major surgical intervention on monocyte functionality, possibly mediated by epigenetic changes that endure the life span of the individual cell.
Collapse
Affiliation(s)
- Benedikt Hermann Siegler
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Jan Niklas Thon
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Marc Altvater
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Judith Schenz
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Jan Larmann
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Markus Alexander Weigand
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| | - Sebastian Weiterer
- Medical Faculty Heidelberg, Department of Anesthesiology, Heidelberg University, Heidelberg, Baden-Württemberg, Germany
| |
Collapse
|
2
|
Boss JM. The Regulation of Immunity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:2450-2455. [PMID: 35595305 DOI: 10.4049/jimmunol.2290007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Abstract
In their AAI President's Addresses reproduced in this issue, Jeremy M. Boss, Ph.D. (AAI '94; AAI president 2019–2020), and Jenny P.-Y. Ting, Ph.D. (AAI '97; AAI president 2020–2021), welcomed attendees to the AAI annual meeting, Virtual IMMUNOLOGY2021™. Due to the SARS-CoV-2 pandemic and the cancellation of IMMUNOLOGY2020™, Dr. Boss and Dr. Ting each presented their respective president's address to open the meeting.
Collapse
Affiliation(s)
- Jeremy M Boss
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322
| |
Collapse
|
3
|
Chandrasekaran V, Oparina N, Garcia-Bonete MJ, Wasén C, Erlandsson MC, Malmhäll-Bah E, Andersson KME, Jensen M, Silfverswärd ST, Katona G, Bokarewa MI. Cohesin-Mediated Chromatin Interactions and Autoimmunity. Front Immunol 2022; 13:840002. [PMID: 35222432 PMCID: PMC8866859 DOI: 10.3389/fimmu.2022.840002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/17/2022] [Indexed: 11/23/2022] Open
Abstract
Proper physiological functioning of any cell type requires ordered chromatin organization. In this context, cohesin complex performs important functions preventing premature separation of sister chromatids after DNA replication. In partnership with CCCTC-binding factor, it ensures insulator activity to organize enhancers and promoters within regulatory chromatin. Homozygous mutations and dysfunction of individual cohesin proteins are embryonically lethal in humans and mice, which limits in vivo research work to embryonic stem cells and progenitors. Conditional alleles of cohesin complex proteins have been generated to investigate their functional roles in greater detail at later developmental stages. Thus, genome regulation enabled by action of cohesin proteins is potentially crucial in lineage cell development, including immune homeostasis. In this review, we provide current knowledge on the role of cohesin complex in leukocyte maturation and adaptive immunity. Conditional knockout and shRNA-mediated inhibition of individual cohesin proteins in mice demonstrated their importance in haematopoiesis, adipogenesis and inflammation. Notably, these effects occur rather through changes in transcriptional gene regulation than through expected cell cycle defects. This positions cohesin at the crossroad of immune pathways including NF-kB, IL-6, and IFNγ signaling. Cohesin proteins emerged as vital regulators at early developmental stages of thymocytes and B cells and after antigen challenge. Human genome-wide association studies are remarkably concordant with these findings and present associations between cohesin and rheumatoid arthritis, multiple sclerosis and HLA-B27 related chronic inflammatory conditions. Furthermore, bioinformatic prediction based on protein-protein interactions reveal a tight connection between the cohesin complex and immune relevant processes supporting the notion that cohesin will unearth new clues in regulation of autoimmunity.
Collapse
Affiliation(s)
- Venkataragavan Chandrasekaran
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Nina Oparina
- Rheumatology Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Maria-Jose Garcia-Bonete
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Caroline Wasén
- Ann Romney Center for Neurologic Diseases, Harvard Medical School, Brigham and Women’s Hospital, Boston, MA, United States
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Malin C. Erlandsson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Eric Malmhäll-Bah
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Karin M. E. Andersson
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Maja Jensen
- Department of Chemistry and Molecular Biology, Faculty of Science, University of Gothenburg, Gothenburg, Sweden
| | - Sofia T. Silfverswärd
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Gergely Katona
- Department of Chemistry and Molecular Biology, Faculty of Science, University of Gothenburg, Gothenburg, Sweden
| | - Maria I. Bokarewa
- Department of Rheumatology and Inflammation Research, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden
- Rheumatology Clinic, Sahlgrenska University Hospital, Gothenburg, Sweden
| |
Collapse
|
4
|
Patterson DG, Kania AK, Zuo Z, Scharer CD, Boss JM. Epigenetic gene regulation in plasma cells. Immunol Rev 2021; 303:8-22. [PMID: 34010461 DOI: 10.1111/imr.12975] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022]
Abstract
Humoral immunity provides protection from pathogenic infection and is mediated by antibodies following the differentiation of naive B cells (nBs) to antibody-secreting cells (ASCs). This process requires substantial epigenetic and transcriptional rewiring to ultimately repress the nB program and replace it with one conducive to ASC physiology and function. Notably, these reprogramming events occur within the framework of cell division. Efforts to understand the relationship of cell division with reprogramming and ASC differentiation in vivo have uncovered the timing and scope of reprogramming, as well as key factors that influence these events. Herein, we discuss the unique physiology of ASC and how nBs undergo epigenetic and genome architectural reorganization to acquire the necessary functions to support antibody production. We also discuss the stage-wise manner in which reprogramming occurs across cell divisions and how key molecular determinants can influence B cell fate outcomes.
Collapse
Affiliation(s)
- Dillon G Patterson
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA
| | - Anna K Kania
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA
| | - Zhihong Zuo
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA.,Xiangya School of Medicine, Central South University, Changsha, China
| | | | - Jeremy M Boss
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, USA
| |
Collapse
|
5
|
Scourzic L, Salataj E, Apostolou E. Deciphering the Complexity of 3D Chromatin Organization Driving Lymphopoiesis and Lymphoid Malignancies. Front Immunol 2021; 12:669881. [PMID: 34054841 PMCID: PMC8160312 DOI: 10.3389/fimmu.2021.669881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/26/2021] [Indexed: 12/18/2022] Open
Abstract
Proper lymphopoiesis and immune responses depend on the spatiotemporal control of multiple processes, including gene expression, DNA recombination and cell fate decisions. High-order 3D chromatin organization is increasingly appreciated as an important regulator of these processes and dysregulation of genomic architecture has been linked to various immune disorders, including lymphoid malignancies. In this review, we present the general principles of the 3D chromatin topology and its dynamic reorganization during various steps of B and T lymphocyte development and activation. We also discuss functional interconnections between architectural, epigenetic and transcriptional changes and introduce major key players of genomic organization in B/T lymphocytes. Finally, we present how alterations in architectural factors and/or 3D genome organization are linked to dysregulation of the lymphopoietic transcriptional program and ultimately to hematological malignancies.
Collapse
Affiliation(s)
| | | | - Effie Apostolou
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, United States
| |
Collapse
|
6
|
Majumder P, Lee JT, Barwick BG, Patterson DG, Bally APR, Scharer CD, Boss JM. The Murine MHC Class II Super Enhancer IA/IE-SE Contains a Functionally Redundant CTCF-Binding Component and a Novel Element Critical for Maximal Expression. THE JOURNAL OF IMMUNOLOGY 2021; 206:2221-2232. [PMID: 33863790 DOI: 10.4049/jimmunol.2001089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/01/2021] [Indexed: 11/19/2022]
Abstract
In both humans and mice, CTCF-binding elements form a series of interacting loops across the MHC class II (MHC-II) locus, and CTCF is required for maximal MHC-II gene expression. In humans, a CTCF-bound chromatin insulator termed XL9 and a super enhancer (SE) DR/DQ-SE situated in the intergenic region between HLA-DRB1 and HLA-DQA1 play critical roles in regulating MHC-II expression. In this study, we identify a similar SE, termed IA/IE-SE, located between H2-Eb1 and H2-Aa of the mouse that contains a CTCF site (C15) and a novel region of high histone H3K27 acetylation. A genetic knockout of C15 was created and its role on MHC-II expression tested on immune cells. We found that C15 deletion did not alter MHC-II expression in B cells, macrophages, and macrophages treated with IFN-γ because of functional redundancy of the remaining MHC-II CTCF sites. Surprisingly, embryonic fibroblasts derived from C15-deleted mice failed to induce MHC-II gene expression in response to IFN-γ, suggesting that at least in this developmental lineage, C15 was required. Examination of the three-dimensional interactions with C15 and the H2-Eb1 and H2-Aa promoters identified interactions within the novel region of high histone acetylation within the IA/IE-SE (termed N1) that contains a PU.1 binding site. CRISPR/Cas9 deletion of N1 altered chromatin interactions across the locus and resulted in reduced MHC-II expression. Together, these data demonstrate the functional redundancy of the MHC-II CTCF elements and identify a functionally conserved SE that is critical for maximal expression of MHC-II genes.
Collapse
Affiliation(s)
- Parimal Majumder
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Joshua T Lee
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Benjamin G Barwick
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Dillon G Patterson
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Alexander P R Bally
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Christopher D Scharer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Jeremy M Boss
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| |
Collapse
|
7
|
Majumder P, Lee JT, Rahmberg AR, Kumar G, Mi T, Scharer CD, Boss JM. A super enhancer controls expression and chromatin architecture within the MHC class II locus. J Exp Med 2020; 217:e20190668. [PMID: 31753848 PMCID: PMC7041702 DOI: 10.1084/jem.20190668] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 09/05/2019] [Accepted: 10/14/2019] [Indexed: 12/30/2022] Open
Abstract
Super enhancers (SEs) play critical roles in cell type-specific gene regulation. The mechanisms by which such elements work are largely unknown. Two SEs termed DR/DQ-SE and XL9-SE are situated within the human MHC class II locus between the HLA-DRB1 and HLA-DQA1 genes and are highly enriched for disease-causing SNPs. To test the function of these elements, we used CRISPR/Cas9 to generate a series of mutants that deleted the SE. Deletion of DR/DQ-SE resulted in reduced expression of HLA-DRB1 and HLA-DQA1 genes. The SEs were found to interact with each other and the promoters of HLA-DRB1 and HLA-DQA1. DR/DQ-SE also interacted with neighboring CTCF binding sites. Importantly, deletion of DR/DQ-SE reduced the local chromatin interactions, implying that it functions as the organizer for the local three-dimensional architecture. These data provide direct mechanisms by which an MHC-II SE contributes to expression of the locus and suggest how variation in these SEs may contribute to human disease and altered immunity.
Collapse
Affiliation(s)
- Parimal Majumder
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Joshua T Lee
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Andrew R Rahmberg
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Gaurav Kumar
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Tian Mi
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Christopher D Scharer
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Jeremy M Boss
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| |
Collapse
|
8
|
Arzate-Mejía RG, Recillas-Targa F, Corces VG. Developing in 3D: the role of CTCF in cell differentiation. Development 2018; 145:145/6/dev137729. [PMID: 29567640 DOI: 10.1242/dev.137729] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CTCF is a highly conserved zinc-finger DNA-binding protein that mediates interactions between distant sequences in the genome. As a consequence, CTCF regulates enhancer-promoter interactions and contributes to the three-dimensional organization of the genome. Recent studies indicate that CTCF is developmentally regulated, suggesting that it plays a role in cell type-specific genome organization. Here, we review these studies and discuss how CTCF functions during the development of various cell and tissue types, ranging from embryonic stem cells and gametes, to neural, muscle and cardiac cells. We propose that the lineage-specific control of CTCF levels, and its partnership with lineage-specific transcription factors, allows for the control of cell type-specific gene expression via chromatin looping.
Collapse
Affiliation(s)
- Rodrigo G Arzate-Mejía
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Félix Recillas-Targa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Victor G Corces
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| |
Collapse
|
9
|
Gianfrani C, Pisapia L, Picascia S, Strazzullo M, Del Pozzo G. Expression level of risk genes of MHC class II is a susceptibility factor for autoimmunity: New insights. J Autoimmun 2018; 89:1-10. [PMID: 29331322 DOI: 10.1016/j.jaut.2017.12.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/28/2017] [Accepted: 12/29/2017] [Indexed: 02/08/2023]
Abstract
To date, the study of the impact of major hystocompatibility complex on autoimmunity has been prevalently focused on structural diversity of MHC molecules in binding and presentation of (auto)antigens to cognate T cells. Recently, a number of experimental evidences suggested new points of view to investigate the complex relationships between MHC gene expression and the individual predisposition to autoimmune diseases. Irrespective of the nature of the antigen, a threshold of MHC-peptide complexes needs to be reached, as well as a threshold of T cell receptors engaged is required, for the activation and proliferation of autoantigen-reactive T cells. Moreover, it is well known that increased expression of MHC class II molecules may alter the T cell receptor repertoire during thymic development, and affect the survival and expansion of mature T cells. Many evidences confirmed that the level of both transcriptional and post-transcriptional regulation are involved in the modulation of the expression of MHC class II genes and that both contribute to the predisposition to autoimmune diseases. Here, we aim to focus some of these regulative aspects to better clarify the role of MHC class II genes in predisposition and development of autoimmunity.
Collapse
Affiliation(s)
- Carmen Gianfrani
- Institute of Protein Biochemistry-CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Laura Pisapia
- Institute of Genetics and Biophysics-CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Stefania Picascia
- Institute of Protein Biochemistry-CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Maria Strazzullo
- Institute of Genetics and Biophysics-CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Giovanna Del Pozzo
- Institute of Genetics and Biophysics-CNR, Via Pietro Castellino 111, 80131, Naples, Italy.
| |
Collapse
|
10
|
Banerji R, Skibbens RV, Iovine MK. How many roads lead to cohesinopathies? Dev Dyn 2017; 246:881-888. [PMID: 28422453 DOI: 10.1002/dvdy.24510] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/10/2017] [Accepted: 04/11/2017] [Indexed: 12/16/2023] Open
Abstract
Genetic mapping studies reveal that mutations in cohesion pathways are responsible for multispectrum developmental abnormalities termed cohesinopathies. These include Roberts syndrome (RBS), Cornelia de Lange Syndrome (CdLS), and Warsaw Breakage Syndrome (WABS). The cohesinopathies are characterized by overlapping phenotypes ranging from craniofacial deformities, limb defects, and mental retardation. Though these syndromes share a similar suite of phenotypes and arise due to mutations in a common cohesion pathway, the underlying mechanisms are currently believed to be distinct. Defects in mitotic failure and apoptosis i.e. trans DNA tethering events are believed to be the underlying cause of RBS, whereas the underlying cause of CdLS is largely modeled as occurring through defects in transcriptional processes i.e. cis DNA tethering events. Here, we review recent findings described primarily in zebrafish, paired with additional studies in other model systems, including human patient cells, which challenge the notion that cohesinopathies represent separate syndromes. We highlight numerous studies that illustrate the utility of zebrafish to provide novel insights into the phenotypes, genes affected and the possible mechanisms underlying cohesinopathies. We propose that transcriptional deregulation is the predominant mechanism through which cohesinopathies arise. Developmental Dynamics 246:881-888, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Rajeswari Banerji
- Department of Biological Science, Lehigh University, Bethlehem, Pennsylvania
| | - Robert V Skibbens
- Department of Biological Science, Lehigh University, Bethlehem, Pennsylvania
| | - M Kathryn Iovine
- Department of Biological Science, Lehigh University, Bethlehem, Pennsylvania
| |
Collapse
|
11
|
Bunting KL, Soong TD, Singh R, Jiang Y, Béguelin W, Poloway DW, Swed BL, Hatzi K, Reisacher W, Teater M, Elemento O, Melnick AM. Multi-tiered Reorganization of the Genome during B Cell Affinity Maturation Anchored by a Germinal Center-Specific Locus Control Region. Immunity 2016; 45:497-512. [PMID: 27637145 PMCID: PMC5033726 DOI: 10.1016/j.immuni.2016.08.012] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 06/14/2016] [Accepted: 06/24/2016] [Indexed: 12/11/2022]
Abstract
During the humoral immune response, B cells undergo a dramatic change in phenotype to enable antibody affinity maturation in germinal centers (GCs). Using genome-wide chromosomal conformation capture (Hi-C), we found that GC B cells undergo massive reorganization of the genomic architecture that encodes the GC B cell transcriptome. Coordinate expression of genes that specify the GC B cell phenotype-most prominently BCL6-was achieved through a multilayered chromatin reorganization process involving (1) increased promoter connectivity, (2) formation of enhancer networks, (3) 5' to 3' gene looping, and (4) merging of gene neighborhoods that share active epigenetic marks. BCL6 was an anchor point for the formation of GC-specific gene and enhancer loops on chromosome 3. Deletion of a GC-specific, highly interactive locus control region upstream of Bcl6 abrogated GC formation in mice. Thus, large-scale and multi-tiered genomic three-dimensional reorganization is required for coordinate expression of phenotype-driving gene sets that determine the unique characteristics of GC B cells.
Collapse
Affiliation(s)
- Karen L Bunting
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - T David Soong
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Rajat Singh
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Immunology and Microbial Pathogenesis, Weill Cornell Medical College, New York, NY 10065, USA
| | - Yanwen Jiang
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, USA
| | - Wendy Béguelin
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - David W Poloway
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Brandon L Swed
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Katerina Hatzi
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - William Reisacher
- Department of Otorhinolaryngology, Weill Cornell Medical College/New York Presbyterian Hospital, New York, NY 10065, USA
| | - Matt Teater
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Olivier Elemento
- Institute for Computational Biomedicine, Weill Cornell Medical College, New York, NY 10065, USA.
| | - Ari M Melnick
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA; Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA.
| |
Collapse
|
12
|
Marriott AS, Vasieva O, Fang Y, Copeland NA, McLennan AG, Jones NJ. NUDT2 Disruption Elevates Diadenosine Tetraphosphate (Ap4A) and Down-Regulates Immune Response and Cancer Promotion Genes. PLoS One 2016; 11:e0154674. [PMID: 27144453 PMCID: PMC4856261 DOI: 10.1371/journal.pone.0154674] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/18/2016] [Indexed: 01/04/2023] Open
Abstract
Regulation of gene expression is one of several roles proposed for the stress-induced nucleotide diadenosine tetraphosphate (Ap4A). We have examined this directly by a comparative RNA-Seq analysis of KBM-7 chronic myelogenous leukemia cells and KBM-7 cells in which the NUDT2 Ap4A hydrolase gene had been disrupted (NuKO cells), causing a 175-fold increase in intracellular Ap4A. 6,288 differentially expressed genes were identified with P < 0.05. Of these, 980 were up-regulated and 705 down-regulated in NuKO cells with a fold-change ≥ 2. Ingenuity® Pathway Analysis (IPA®) was used to assign these genes to known canonical pathways and functional networks. Pathways associated with interferon responses, pattern recognition receptors and inflammation scored highly in the down-regulated set of genes while functions associated with MHC class II antigens were prominent among the up-regulated genes, which otherwise showed little organization into major functional gene sets. Tryptophan catabolism was also strongly down-regulated as were numerous genes known to be involved in tumor promotion in other systems, with roles in the epithelial-mesenchymal transition, proliferation, invasion and metastasis. Conversely, some pro-apoptotic genes were up-regulated. Major upstream factors predicted by IPA® for gene down-regulation included NFκB, STAT1/2, IRF3/4 and SP1 but no major factors controlling gene up-regulation were identified. Potential mechanisms for gene regulation mediated by Ap4A and/or NUDT2 disruption include binding of Ap4A to the HINT1 co-repressor, autocrine activation of purinoceptors by Ap4A, chromatin remodeling, effects of NUDT2 loss on transcript stability, and inhibition of ATP-dependent regulatory factors such as protein kinases by Ap4A. Existing evidence favors the last of these as the most probable mechanism. Regardless, our results suggest that the NUDT2 protein could be a novel cancer chemotherapeutic target, with its inhibition potentially exerting strong anti-tumor effects via multiple pathways involving metastasis, invasion, immunosuppression and apoptosis.
Collapse
MESH Headings
- Cell Line, Tumor
- Dinucleoside Phosphates/metabolism
- Down-Regulation
- Gene Expression Profiling
- Gene Knockout Techniques
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/immunology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Phosphoric Monoester Hydrolases/deficiency
- Phosphoric Monoester Hydrolases/genetics
Collapse
Affiliation(s)
- Andrew S. Marriott
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Olga Vasieva
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Yongxiang Fang
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Nikki A. Copeland
- Division of Biomedical and Life Sciences, University of Lancaster, Lancaster, Lancashire, United Kingdom
| | - Alexander G. McLennan
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail: (AGM); (NJJ)
| | - Nigel J. Jones
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail: (AGM); (NJJ)
| |
Collapse
|
13
|
Mora A, Sandve GK, Gabrielsen OS, Eskeland R. In the loop: promoter-enhancer interactions and bioinformatics. Brief Bioinform 2015; 17:980-995. [PMID: 26586731 PMCID: PMC5142009 DOI: 10.1093/bib/bbv097] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 09/26/2015] [Indexed: 12/17/2022] Open
Abstract
Enhancer-promoter regulation is a fundamental mechanism underlying differential transcriptional regulation. Spatial chromatin organization brings remote enhancers in contact with target promoters in cis to regulate gene expression. There is considerable evidence for promoter-enhancer interactions (PEIs). In the recent years, genome-wide analyses have identified signatures and mapped novel enhancers; however, being able to precisely identify their target gene(s) requires massive biological and bioinformatics efforts. In this review, we give a short overview of the chromatin landscape and transcriptional regulation. We discuss some key concepts and problems related to chromatin interaction detection technologies, and emerging knowledge from genome-wide chromatin interaction data sets. Then, we critically review different types of bioinformatics analysis methods and tools related to representation and visualization of PEI data, raw data processing and PEI prediction. Lastly, we provide specific examples of how PEIs have been used to elucidate a functional role of non-coding single-nucleotide polymorphisms. The topic is at the forefront of epigenetic research, and by highlighting some future bioinformatics challenges in the field, this review provides a comprehensive background for future PEI studies.
Collapse
|
14
|
Scharer CD, Choi NM, Barwick BG, Majumder P, Lohsen S, Boss JM. Genome-wide CIITA-binding profile identifies sequence preferences that dictate function versus recruitment. Nucleic Acids Res 2015; 43:3128-42. [PMID: 25753668 PMCID: PMC4381081 DOI: 10.1093/nar/gkv182] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 02/20/2015] [Accepted: 02/24/2015] [Indexed: 01/06/2023] Open
Abstract
The class II transactivator (CIITA) is essential for the expression of major histocompatibility complex class II (MHC-II) genes; however, the role of CIITA in gene regulation outside of MHC-II biology is not fully understood. To comprehensively map CIITA-bound loci, ChIP-seq was performed in the human B lymphoblastoma cell line Raji. CIITA bound 480 sites, and was significantly enriched at active promoters and enhancers. The complexity of CIITA transcriptional regulation of target genes was analyzed using a combination of CIITA-null cells, including a novel cell line created using CRISPR/Cas9 tools. MHC-II genes and a few novel genes were regulated by CIITA; however, most other genes demonstrated either diminished or no changes in the absence of CIITA. Nearly all CIITA-bound sites were within regions containing accessible chromatin, and CIITA's presence at these sites was associated with increased histone H3K27 acetylation, suggesting that CIITA's role at these non-regulated loci may be to poise the region for subsequent regulation. Computational genome-wide modeling of the CIITA bound XY box motifs provided constraints for sequences associated with CIITA-mediated gene regulation versus binding. These data therefore define the CIITA regulome in B cells and establish sequence specificities that predict activity for an essential regulator of the adaptive immune response.
Collapse
Affiliation(s)
| | - Nancy M Choi
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
| | - Benjamin G Barwick
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
| | - Parimal Majumder
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
| | - Sarah Lohsen
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
| | - Jeremy M Boss
- Department of Microbiology and Immunology, Emory University, Atlanta, GA 30322, USA
| |
Collapse
|
15
|
Majumder P, Scharer CD, Choi NM, Boss JM. B cell differentiation is associated with reprogramming the CCCTC binding factor-dependent chromatin architecture of the murine MHC class II locus. THE JOURNAL OF IMMUNOLOGY 2014; 192:3925-35. [PMID: 24634495 DOI: 10.4049/jimmunol.1303205] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The transcriptional insulator CCCTC binding factor (CTCF) was shown previously to be critical for human MHC class II (MHC-II) gene expression. Whether the mechanisms used by CTCF in humans were similar to that of the mouse and whether the three-dimensional chromatin architecture created was specific to B cells were not defined. Genome-wide CTCF occupancy was defined for murine B cells and LPS-derived plasmablasts by chromatin immunoprecipitation sequencing. Fifteen CTCF sites within the murine MHC-II locus were associated with high CTCF binding in B cells. Only one-third of these sites displayed significant CTCF occupancy in plasmablasts. CTCF was required for maximal MHC-II gene expression in mouse B cells. In B cells, a subset of the CTCF regions interacted with each other, creating a three-dimensional architecture for the locus. Additional interactions occurred between MHC-II promoters and the CTCF sites. In contrast, a novel configuration occurred in plasma cells, which do not express MHC-II genes. Ectopic CIITA expression in plasma cells to induce MHC-II expression resulted in high levels of MHC-II proteins, but did not alter the plasma cell architecture completely. These data suggest that reorganizing the three-dimensional chromatin architecture is an epigenetic mechanism that accompanies the silencing of MHC-II genes as part of the cell fate commitment of plasma cells.
Collapse
Affiliation(s)
- Parimal Majumder
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322
| | | | | | | |
Collapse
|
16
|
Ball AR, Chen YY, Yokomori K. Mechanisms of cohesin-mediated gene regulation and lessons learned from cohesinopathies. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1839:191-202. [PMID: 24269489 PMCID: PMC3951616 DOI: 10.1016/j.bbagrm.2013.11.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 11/09/2013] [Accepted: 11/14/2013] [Indexed: 12/16/2022]
Abstract
Cohesins are conserved and essential Structural Maintenance of Chromosomes (SMC) protein-containing complexes that physically interact with chromatin and modulate higher-order chromatin organization. Cohesins mediate sister chromatid cohesion and cellular long-distance chromatin interactions affecting genome maintenance and gene expression. Discoveries of mutations in cohesin's subunits and its regulator proteins in human developmental disorders, so-called "cohesinopathies," reveal crucial roles for cohesins in development and cellular growth and differentiation. In this review, we discuss the latest findings concerning cohesin's functions in higher-order chromatin architecture organization and gene regulation and new insight gained from studies of cohesinopathies. This article is part of a Special Issue entitled: Chromatin and epigenetic regulation of animal development.
Collapse
Affiliation(s)
- Alexander R Ball
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700, USA
| | - Yen-Yun Chen
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700, USA
| | - Kyoko Yokomori
- Department of Biological Chemistry, School of Medicine, University of California, Irvine, CA 92697-1700, USA.
| |
Collapse
|
17
|
Mégarbané A, Noguier F, Stora S, Manchon L, Mircher C, Bruno R, Dorison N, Pierrat F, Rethoré MO, Trentin B, Ravel A, Morent M, Lefranc G, Piquemal D. The intellectual disability of trisomy 21: differences in gene expression in a case series of patients with lower and higher IQ. Eur J Hum Genet 2013; 21:1253-9. [PMID: 23422941 PMCID: PMC3798834 DOI: 10.1038/ejhg.2013.24] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 12/27/2012] [Accepted: 01/22/2013] [Indexed: 12/25/2022] Open
Abstract
Trisomy 21 (T21), or Down syndrome (DS), is the most frequent and recognizable cause of intellectual disabilities. The level of disability, as evaluated by the intelligence quotient (IQ) test, varies considerably between patients independent of other factors. To determine the genetic or molecular basis of this difference, a high throughput transcriptomic analysis was performed on twenty T21 patients with high and low IQ, and 10 healthy controls using Digital Gene Expression. More than 90 millions of tags were sequenced in the three libraries. A total of 80 genes of potential interest were selected for the qPCR experiment validation, and three housekeeping genes were used for normalizing purposes. HLA DQA1 and HLA DRB1 were significantly downregulated among the patients with a low IQ, the values found in the healthy controls being intermediate between those noted in the IQ+ and IQ- T21 patients. Interestingly, the intergenic region between these genes contains a binding sequence for the CCCTC-binding factor, or CTCF, and cohesin (a multisubunit complex), both of which are essential for expression of HLA DQA1 and HLA DRB1 and numerous other genes. Our results might lead to the discovery of genes, or genetic markers, that are directly involved in several phenotypes of DS and, eventually, to the identification of potential targets for therapeutic interventions.
Collapse
Affiliation(s)
- André Mégarbané
- Institut Jérôme Lejeune, Paris, France
- Unité de Génétique Médicale et Laboratoire Associé INSERM UMR_S910, Beirut, Lebanon
| | | | | | | | | | | | | | | | | | | | | | | | - Gerard Lefranc
- Université Montpellier 2 et CNRS UPR 1142, Institut de Génétique Humaine, Montpellier, France
| | | |
Collapse
|
18
|
Mehta GD, Kumar R, Srivastava S, Ghosh SK. Cohesin: functions beyond sister chromatid cohesion. FEBS Lett 2013; 587:2299-312. [PMID: 23831059 DOI: 10.1016/j.febslet.2013.06.035] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 06/23/2013] [Accepted: 06/24/2013] [Indexed: 11/22/2022]
Abstract
Faithful segregation of chromosomes during mitosis and meiosis is the cornerstone process of life. Cohesin, a multi-protein complex conserved from yeast to human, plays a crucial role in this process by keeping the sister chromatids together from S-phase to anaphase onset during mitosis and meiosis. Technological advancements have discovered myriad functions of cohesin beyond its role in sister chromatid cohesion (SCC), such as transcription regulation, DNA repair, chromosome condensation, homolog pairing, monoorientation of sister kinetochore, etc. Here, we have focused on such functions of cohesin that are either independent of or dependent on its canonical role of sister chromatid cohesion. At the end, human diseases associated with malfunctioning of cohesin, albeit with mostly unperturbed sister chromatid cohesion, have been discussed.
Collapse
Affiliation(s)
- Gunjan D Mehta
- Department of Biosciences and Bioengineering, Wadhwani Research Centre for Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Mumbai 400076, India
| | | | | | | |
Collapse
|
19
|
Berrozpe G, Bryant GO, Warpinski K, Ptashne M. Regulation of a mammalian gene bearing a CpG island promoter and a distal enhancer. Cell Rep 2013; 4:445-53. [PMID: 23911283 DOI: 10.1016/j.celrep.2013.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 06/04/2013] [Accepted: 07/01/2013] [Indexed: 11/30/2022] Open
Abstract
A quantitative nucleosome occupancy assay revealed rules for nucleosome disposition in yeast and showed how disposition affects regulation of the GAL genes. Here, we show how those findings apply to the control of Kit, a mammalian gene. The Kit promoter lies in a CpG island, and its enhancer (active in mast cells) lies some 150 kb upstream. Nucleosomes form with especially high avidities at the Kit promoter, a reaction that, we surmise, ensures extremely low basal expression. In mast cells, transcriptional activators displace nucleosomes that are less tightly formed at the Kit enhancer. In turn, the active enhancer replaces a single Kit promoter nucleosome with the transcriptional machinery, thereby inducing transcription over 1,000-fold. As at the yeast GAL genes, the inhibitory effects of nucleosomes facilitate high factors of induction by mammalian activators working in the absence of specific repressors.
Collapse
Affiliation(s)
- Georgina Berrozpe
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, 430 East 67(th) Street, New York, NY 10065, USA
| | | | | | | |
Collapse
|
20
|
DeMare LE, Leng J, Cotney J, Reilly SK, Yin J, Sarro R, Noonan JP. The genomic landscape of cohesin-associated chromatin interactions. Genome Res 2013; 23:1224-34. [PMID: 23704192 PMCID: PMC3730097 DOI: 10.1101/gr.156570.113] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/20/2013] [Indexed: 12/19/2022]
Abstract
Cohesin is implicated in establishing tissue-specific DNA loops that target enhancers to promoters, and also localizes to sites bound by the insulator protein CTCF, which blocks enhancer-promoter communication. However, cohesin-associated interactions have not been characterized on a genome-wide scale. Here we performed chromatin interaction analysis with paired-end tag sequencing (ChIA-PET) of the cohesin subunit SMC1A in developing mouse limb. We identified 2264 SMC1A interactions, of which 1491 (65%) involved sites co-occupied by CTCF. SMC1A participates in tissue-specific enhancer-promoter interactions and interactions that demarcate regions of correlated regulatory output. In contrast to previous studies, we also identified interactions between promoters and distal sites that are maintained in multiple tissues but are poised in embryonic stem cells and resolve to tissue-specific activated or repressed chromatin states in the mouse embryo. Our results reveal the diversity of cohesin-associated interactions in the genome and highlight their role in establishing the regulatory architecture of development.
Collapse
Affiliation(s)
- Laura E. DeMare
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Jing Leng
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut 06520, USA
| | - Justin Cotney
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Steven K. Reilly
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Jun Yin
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - Richard Sarro
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| | - James P. Noonan
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut 06520, USA
- Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| |
Collapse
|
21
|
Holwerda SJB, de Laat W. CTCF: the protein, the binding partners, the binding sites and their chromatin loops. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120369. [PMID: 23650640 PMCID: PMC3682731 DOI: 10.1098/rstb.2012.0369] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CTCF has it all. The transcription factor binds to tens of thousands of genomic sites, some tissue-specific, others ultra-conserved. It can act as a transcriptional activator, repressor and insulator, and it can pause transcription. CTCF binds at chromatin domain boundaries, at enhancers and gene promoters, and inside gene bodies. It can attract many other transcription factors to chromatin, including tissue-specific transcriptional activators, repressors, cohesin and RNA polymerase II, and it forms chromatin loops. Yet, or perhaps therefore, CTCF's exact function at a given genomic site is unpredictable. It appears to be determined by the associated transcription factors, by the location of the binding site relative to the transcriptional start site of a gene, and by the site's engagement in chromatin loops with other CTCF-binding sites, enhancers or gene promoters. Here, we will discuss genome-wide features of CTCF binding events, as well as locus-specific functions of this remarkable transcription factor.
Collapse
Affiliation(s)
| | - Wouter de Laat
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| |
Collapse
|
22
|
Panigrahi AK, Pati D. Higher-order orchestration of hematopoiesis: is cohesin a new player? Exp Hematol 2012; 40:967-73. [PMID: 23022223 PMCID: PMC3595174 DOI: 10.1016/j.exphem.2012.09.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 09/10/2012] [Accepted: 09/21/2012] [Indexed: 12/20/2022]
Abstract
Hematopoiesis-the process that generates distinct lineage-committed blood cells from a single multipotent hematopoietic stem cell-is a complex process of cellular differentiation regulated by a set of dynamic transcriptional programs. Cytokines and growth factors, transcription factors, chromatin remodeling, and modifying enzymes have been suggested to enact critical roles during hematopoiesis, leading to the development of myeloid, lymphoid, erythroid and platelet precursors. How is such a complex process orchestrated? Is there a higher order of hematopoiesis regulation? These are some of the unresolved questions in the field of hematopoiesis. Here, we suggest that cohesin, which is known to mediate chromosomal cohesion between sister chromatids, may have a central role in the orchestration of hematopoiesis and serve as a master transcriptional regulator.
Collapse
Affiliation(s)
- Anil K Panigrahi
- Texas Children's Cancer Center, Department of Pediatric Hematology/Oncology, Baylor College of Medicine, Houston, TX 77030, USA.
| | | |
Collapse
|
23
|
Holwerda S, de Laat W. Chromatin loops, gene positioning, and gene expression. Front Genet 2012; 3:217. [PMID: 23087710 PMCID: PMC3473233 DOI: 10.3389/fgene.2012.00217] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 10/01/2012] [Indexed: 01/09/2023] Open
Abstract
Technological developments and intense research over the last years have led to a better understanding of the 3D structure of the genome and its influence on genome function inside the cell nucleus. We will summarize topological studies performed on four model gene loci: the α- and β-globin gene loci, the antigen receptor loci, the imprinted H19-Igf2 locus and the Hox gene clusters. Collectively, these studies show that regulatory DNA sequences physically contact genes to control their transcription. Proteins set up the 3D configuration of the genome and we will discuss the roles of the key structural organizers CTCF and cohesin, the nuclear lamina and the transcription machinery. Finally, genes adopt non-random positions in the nuclear interior. We will review studies on gene positioning and propose that cell-specific genome conformations can juxtapose a regulatory sequence on one chromosome to a responsive gene on another chromosome to cause altered gene expression in subpopulations of cells.
Collapse
Affiliation(s)
- Sjoerd Holwerda
- Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences, University Medical Center Utrecht Utrecht, Netherlands
| | | |
Collapse
|
24
|
Chen HS, Wikramasinghe P, Showe L, Lieberman PM. Cohesins repress Kaposi's sarcoma-associated herpesvirus immediate early gene transcription during latency. J Virol 2012; 86:9454-64. [PMID: 22740398 PMCID: PMC3416178 DOI: 10.1128/jvi.00787-12] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 06/14/2012] [Indexed: 12/14/2022] Open
Abstract
Chromatin-organizing factors such as CTCF and cohesins have been implicated in the control of complex viral regulatory programs. We investigated the role of CTCF and cohesins in the control of the switch from latency to the lytic cycle for Kaposi's sarcoma-associated herpesvirus (KSHV). We found that cohesin subunits but not CTCF are required for the repression of KSHV immediate early gene transcription. Depletion of the cohesin subunits Rad21, SMC1, and SMC3 resulted in lytic cycle gene transcription and viral DNA replication. In contrast, depletion of CTCF failed to induce lytic transcription or DNA replication. Chromatin immunoprecipitation with high-throughput sequencing (ChIP-Seq) revealed that cohesins and CTCF bound to several sites within the immediate early control region for ORF50 and to more distal 5' sites that also regulate the divergently transcribed ORF45-ORF46-ORF47 gene cluster. Rad21 depletion led to a robust increase in ORF45, ORF46, ORF47, and ORF50 transcripts, with similar kinetics to that observed with chemical induction by sodium butyrate. During latency, the chromatin between the ORF45 and ORF50 transcription start sites was enriched in histone H3K4me3, with elevated H3K9ac at the ORF45 promoter and elevated H3K27me3 at the ORF50 promoter. A paused form of RNA polymerase II (Pol II) was loosely associated with the ORF45 promoter region during latency but was converted to an active elongating form upon reactivation induced by Rad21 depletion. Butyrate treatment caused a rapid dissociation of cohesins and loss of CTCF binding at the immediate early gene locus, suggesting that cohesins may be a direct target of butyrate-mediated lytic induction. Our findings implicate cohesins as a major repressor of KSHV lytic gene activation and show that they function coordinately with CTCF to regulate the switch between latent and lytic gene activity.
Collapse
|
25
|
Abstract
Long-range interactions between transcription regulatory elements play an important role in gene activation, epigenetic silencing, and chromatin organization. Transcriptional activation or repression of developmentally regulated genes is often accomplished through tissue-specific chromatin architecture and dynamic localization between active transcription factories and repressive Polycomb bodies. However, the mechanisms underlying the structural organization of chromatin and the coordination of physical interactions are not fully understood. Insulators and Polycomb group proteins form highly conserved multiprotein complexes that mediate functional long-range interactions and have proposed roles in nuclear organization. In this review, we explore recent findings that have broadened our understanding of the function of these proteins and provide an integrative model for the roles of insulators in nuclear organization.
Collapse
Affiliation(s)
- Kevin Van Bortle
- Department of Biology, Emory University, Atlanta, Georgia 30322, USA
| | | |
Collapse
|
26
|
Abstract
The cohesin complex, named for its key role in sister chromatid cohesion, also plays critical roles in gene regulation and DNA repair. It performs all three functions in single cell eukaryotes such as yeasts, and in higher organisms such as man. Minor disruption of cohesin function has significant consequences for human development, even in the absence of measurable effects on chromatid cohesion or chromosome segregation. Here we survey the roles of cohesin in gene regulation and DNA repair, and how these functions vary from yeast to man.
Collapse
Affiliation(s)
- Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA.
| | | |
Collapse
|
27
|
Seitan VC, Merkenschlager M. Cohesin and chromatin organisation. Curr Opin Genet Dev 2012; 22:93-100. [PMID: 22155130 DOI: 10.1016/j.gde.2011.11.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 11/10/2011] [Indexed: 01/20/2023]
Abstract
Cohesin defines the topology of chromosomes in mitosis and meiosis by holding sister chromatids together; more recently a role for cohesin in chromatin organisation and gene expression in interphase has emerged.
Collapse
Affiliation(s)
- Vlad C Seitan
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College London, London W12 0NN, UK.
| | | |
Collapse
|
28
|
Krivega I, Dean A. Enhancer and promoter interactions-long distance calls. Curr Opin Genet Dev 2012; 22:79-85. [PMID: 22169023 PMCID: PMC3342482 DOI: 10.1016/j.gde.2011.11.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 11/09/2011] [Indexed: 12/23/2022]
Abstract
In metazoans, enhancers of gene transcription must often exert their effects over tens of kilobases of DNA. Over the past decade it has become clear that to do this, enhancers come into close proximity with target promoters with the looping away of intervening sequences. In a few cases proteins that are involved in the establishment or maintenance of these loops have been revealed but how the proper gene target is selected remains mysterious. Chromatin insulators had been appreciated as elements that play a role in enhancer fidelity through their enhancer blocking or barrier activity. However, recent work suggests more direct participation of insulators in enhancer-gene interactions. The emerging view begins to incorporate transcription activation by distant enhancers with large scale nuclear architecture and subnuclear movement.
Collapse
Affiliation(s)
- Ivan Krivega
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20982
| | - Ann Dean
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20982
| |
Collapse
|