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Severa M, Islam SA, Waggoner SN, Jiang Z, Kim ND, Ryan G, Kurt-Jones E, Charo I, Caffrey DR, Boyartchuk VL, Luster AD, Fitzgerald KA. The transcriptional repressor BLIMP1 curbs host defenses by suppressing expression of the chemokine CCL8. THE JOURNAL OF IMMUNOLOGY 2014; 192:2291-304. [PMID: 24477914 DOI: 10.4049/jimmunol.1301799] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The transcriptional repressor B lymphocyte-induced maturation protein 1 (BLIMP1) is a master regulator of B and T cell differentiation. To examine the role of BLIMP1 in innate immunity, we used a conditional knockout (CKO) of Blimp1 in myeloid cells and found that Blimp1 CKO mice were protected from lethal infection induced by Listeria monocytogenes. Transcriptome analysis of Blimp1 CKO macrophages identified the murine chemokine (C-C motif) ligand 8, CCL8, as a direct target of Blimp1-mediated transcriptional repression in these cells. BLIMP1-deficient macrophages expressed elevated levels of Ccl8, and consequently Blimp1 CKO mice had higher levels of circulating CCL8, resulting in increased neutrophils in the peripheral blood, promoting a more aggressive antibacterial response. Mice lacking the Ccl8 gene were more susceptible to L. monocytogenes infection than were wild-type mice. Although CCL8 failed to recruit neutrophils directly, it was chemotactic for γ/δ T cells, and CCL8-responsive γ/δ T cells were enriched for IL-17F. Finally, CCL8-mediated enhanced clearance of L. monocytogenes was dependent on γ/δ T cells. Collectively, these data reveal an important role for BLIMP1 in modulating host defenses by suppressing expression of the chemokine CCL8.
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Affiliation(s)
- Martina Severa
- Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605
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102
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Swider A, Siegel R, Eskdale J, Gallagher G. Regulation of interferon lambda-1 (IFNL1/IFN-λ1/IL-29) expression in human colon epithelial cells. Cytokine 2014; 65:17-23. [PMID: 24140069 DOI: 10.1016/j.cyto.2013.09.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 08/14/2013] [Accepted: 09/23/2013] [Indexed: 12/21/2022]
Abstract
The efficient regulation of intestinal immune responses is critical to colon health. Viruses, for example noraviruses, are key pathogens of the intestine. The lambda interferons (comprising three ligands: IFNL1, L2 and L3 - the so-called "Type III" interferons) constitute the most recently discovered IFN family and are known to be important in intestinal anti-viral defense. A fourth family member, IFNL4, was recently described. Expression of the IFN-lambda receptor is restricted to epithelial and immune cells; together, these ligands and their receptor represent an important anti-viral and immunoregulatory component of the immune/epithelial inteface. We investigated control of IFNL1 expression in human colon epithelial cells. We used the TLR3 agonist poly I:C to drive expression of IFNL1 in SW480 cells, and small interfering RNA (siRNA) to knockdown target transcription factors. We identified ZEB1 and BLIMP-1 as transcription factors that strongly inhibited IFNL1 expression in SW480 cells. Interestingly, while BLIMP-1 inhibited both type-III and type-I interferons (IFN-β), the inhibitory action of ZEB1 was specific for IFNL1. We also defined the NF-κB family member, p65 as a key activator of IFNL1 and NF-κB p50 as a key inhibitor. Finally, we demonstrated that siRNA targeting of ZEB1 or NF-κB p50 resulted in a significant elevation of secreted IFN-λ1 protein and expression of the anti-viral gene OAS1, while knockdown of p65 inhibited these events. Our data provide insight to the regulation of IFNL1 expression in the human colon and suggest novel therapeutic approaches to elevate IFNλ-1 protein where required.
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Affiliation(s)
- Adam Swider
- Genetic Immunology Laboratory, HUMIGEN LLC, 2439 Kuser Road, Hamilton, NJ 08690, United States(1)
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103
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Identification and expression profiles of prdm1 in medaka Oryzias latipes. Mol Biol Rep 2013; 41:617-26. [PMID: 24343424 DOI: 10.1007/s11033-013-2899-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 12/09/2013] [Indexed: 12/13/2022]
Abstract
Mouse Prdm1, also known as Blimp1, plays important roles in maturation and survival of lymphoid cells, as well as in organogenesis of muscle, limb, sensor organs and primordial germ cells. The homologues of mouse prdm1 have been identified in a diverse of animals including zebrafish and fugu. Here, we report the identification and expression profiles of two homologues of prdm1, namely prdm1a and prdm1b in medaka, Oryzias latipes. The transcripts of prdm1a and prdm1b were detectable in all the tissues including immune organs such as gill, spleen, kidney, liver and intestine that we have checked on. The transcripts of prdm1a could be detected in the embryonic shield at mid-gastrula stage and later in the somite, eye, otic vesicle, branchial arches, fin, intestine and cloaca during embryogenesis using in situ hybridization. Moreover, the expression of prdm1a in the liver of both medaka and zebrafish could be up-regulated by the immune stimuli including lipopolysaccharide, polyI:C and the grass carp reovirus, similarly to the up-regulation of IL1B. These results indicate that Prdm1a may play important roles in embryogenesis and also in immune response in fish.
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104
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Hodgkin Disease Therapy Induced Second Malignancy Susceptibility 6q21 Functional Variants in Roma and Hungarian Population Samples. Pathol Oncol Res 2013; 20:529-33. [DOI: 10.1007/s12253-013-9724-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 11/11/2013] [Indexed: 10/25/2022]
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105
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Parlato S, Bruni R, Fragapane P, Salerno D, Marcantonio C, Borghi P, Tataseo P, Ciccaglione AR, Presutti C, Romagnoli G, Bozzoni I, Belardelli F, Gabriele L. IFN-α regulates Blimp-1 expression via miR-23a and miR-125b in both monocytes-derived DC and pDC. PLoS One 2013; 8:e72833. [PMID: 23977359 PMCID: PMC3745402 DOI: 10.1371/journal.pone.0072833] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 07/15/2013] [Indexed: 01/04/2023] Open
Abstract
Type I interferon (IFN-I) have emerged as crucial mediators of cellular signals controlling DC differentiation and function. Human DC differentiated from monocytes in the presence of IFN-α (IFN-α DC) show a partially mature phenotype and a special capability of stimulating CD4+ T cell and cross-priming CD8+ T cells. Likewise, plasmacytoid DC (pDC) are blood DC highly specialized in the production of IFN-α in response to viruses and other danger signals, whose functional features may be shaped by IFN-I. Here, we investigated the molecular mechanisms stimulated by IFN-α in driving human monocyte-derived DC differentiation and performed parallel studies on peripheral unstimulated and IFN-α-treated pDC. A specific miRNA signature was induced in IFN-α DC and selected miRNAs, among which miR-23a and miR-125b, proved to be negatively associated with up-modulation of Blimp-1 occurring during IFN-α-driven DC differentiation. Of note, monocyte-derived IFN-α DC and in vitro IFN-α-treated pDC shared a restricted pattern of miRNAs regulating Blimp-1 expression as well as some similar phenotypic, molecular and functional hallmarks, supporting the existence of a potential relationship between these DC populations. On the whole, these data uncover a new role of Blimp-1 in human DC differentiation driven by IFN-α and identify Blimp-1 as an IFN-α-mediated key regulator potentially accounting for shared functional features between IFN-α DC and pDC.
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Affiliation(s)
- Stefania Parlato
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Roberto Bruni
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Fragapane
- Institute of Molecular Biology and Pathology, Consiglio Nazionale delle Ricerche, Rome, Italy
| | - Debora Salerno
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Cinzia Marcantonio
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Borghi
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Tataseo
- Transfusional Medicine and Molecular Biology Laboratory, ASL, Avezzano-Sulmona, Sulmona, Italy
| | - Anna Rita Ciccaglione
- Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Carlo Presutti
- Department of Genetics and Molecular Biology, Sapienza University, Rome, Italy
| | - Giulia Romagnoli
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Irene Bozzoni
- Department of Genetics and Molecular Biology, Sapienza University, Rome, Italy
| | - Filippo Belardelli
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Lucia Gabriele
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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106
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Magnúsdóttir E, Dietmann S, Murakami K, Günesdogan U, Tang F, Bao S, Diamanti E, Lao K, Gottgens B, Surani MA. A tripartite transcription factor network regulates primordial germ cell specification in mice. Nat Cell Biol 2013; 15:905-15. [PMID: 23851488 PMCID: PMC3796875 DOI: 10.1038/ncb2798] [Citation(s) in RCA: 201] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 06/03/2013] [Indexed: 12/11/2022]
Abstract
Transitions in cell states are controlled by combinatorial actions of transcription factors. BLIMP1, the key regulator of primordial germ cell (PGC) specification, apparently acts together with PRDM14 and AP2γ. To investigate their individual and combinatorial functions, we first sought an in vitro system for transcriptional readouts and chromatin immunoprecipitation sequencing analysis. We then integrated this data with information from single-cell transcriptome analysis of normal and mutant PGCs. Here we show that BLIMP1 binds directly to repress somatic and cell proliferation genes. It also directly induces AP2γ, which together with PRDM14 initiates the PGC-specific fate. We determined the occupancy of critical genes by AP2γ-which, when computed altogether with those of BLIMP1 and PRDM14 (both individually and cooperatively), reveals a tripartite mutually interdependent transcriptional network for PGCs. We also demonstrate that, in principle, BLIMP1, AP2γ and PRDM14 are sufficient for PGC specification, and the unprecedented resetting of the epigenome towards a basal state.
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Affiliation(s)
- Erna Magnúsdóttir
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
| | - Sabine Dietmann
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | - Kazuhiro Murakami
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
| | - Ufuk Günesdogan
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
| | - Fuchou Tang
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
| | - Siqin Bao
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
| | - Evangelia Diamanti
- Cambridge Institute for Medical Research, Wellcome Trust–MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - Kaiqin Lao
- Genetic Systems, Applied Biosystems, Part of Life Technologies, 850 Lincoln Centre Drive, Foster City, CA 94404, USA
| | - Bertie Gottgens
- Cambridge Institute for Medical Research, Wellcome Trust–MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom
| | - M. Azim Surani
- Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, United Kingdom
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
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107
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Jackson HE, Ingham PW. Control of muscle fibre-type diversity during embryonic development: the zebrafish paradigm. Mech Dev 2013; 130:447-57. [PMID: 23811405 DOI: 10.1016/j.mod.2013.06.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 06/04/2013] [Accepted: 06/04/2013] [Indexed: 01/01/2023]
Abstract
Vertebrate skeletal muscle is composed of distinct types of fibre that are functionally adapted through differences in their physiological and metabolic properties. An understanding of the molecular basis of fibre-type specification is of relevance to human health and fitness. The zebrafish provides an attractive model for investigating fibre type specification; not only are their rapidly developing embryos optically transparent, but in contrast to amniotes, the embryonic myotome shows a discrete temporal and spatial separation of fibre type ontogeny that simplifies its analysis. Here we review the current state of understanding of muscle fibre type specification and differentiation during embryonic development of the zebrafish, with a particular focus on the roles of the Prdm1a and Sox6 transcription factors, and consider the relevance of these findings to higher vertebrate muscle biology.
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Affiliation(s)
- Harriet E Jackson
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
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108
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Amalraj J, Cutler SJ, Ghazawi I, Boyle GM, Ralph SJ. REST Negatively and ISGF3 Positively Regulate the Human STAT1 Gene in Melanoma. Mol Cancer Ther 2013; 12:1288-98. [DOI: 10.1158/1535-7163.mct-12-0923] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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109
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Seervai RNH, Wessel GM. Lessons for inductive germline determination. Mol Reprod Dev 2013; 80:590-609. [PMID: 23450642 DOI: 10.1002/mrd.22151] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 01/03/2013] [Indexed: 12/25/2022]
Abstract
Formation of the germline in an embryo marks a fresh round of reproductive potential, yet the developmental stage and location within the embryo where the primordial germ cells (PGCs) form differs wildly among species. In most animals, the germline is formed either by an inherited mechanism, in which maternal provisions within the oocyte drive localized germ-cell fate once acquired in the embryo, or an inductive mechanism that involves signaling between cells that directs germ-cell fate. The inherited mechanism has been widely studied in model organisms such as Drosophila melanogaster, Caenorhabditis elegans, Xenopus laevis, and Danio rerio. Given the rapid generation time and the effective adaptation for laboratory research of these organisms, it is not coincidental that research on these organisms has led the field in elucidating mechanisms for germline specification. The inductive mechanism, however, is less well understood and is studied primarily in the mouse (Mus musculus). In this review, we compare and contrast these two fundamental mechanisms for germline determination, beginning with the key molecular determinants that play a role in the formation of germ cells across all animal taxa. We next explore the current understanding of the inductive mechanism of germ-cell determination in mice, and evaluate the hypotheses for selective pressures on these contrasting mechanisms. We then discuss the hypothesis that the transition between these determination mechanisms, which has happened many times in phylogeny, is more of a continuum than a binary change. Finally, we propose an analogy between germline determination and sex determination in vertebrates-two of the milestones of reproduction and development-in which animals use contrasting strategies to activate similar pathways.
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Affiliation(s)
- Riyad N H Seervai
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, 02192, USA
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110
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PRDM1 is directly targeted by miR-30a-5p and modulates the Wnt/β-catenin pathway in a Dkk1-dependent manner during glioma growth. Cancer Lett 2013; 331:211-9. [PMID: 23348703 DOI: 10.1016/j.canlet.2013.01.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/30/2012] [Accepted: 01/03/2013] [Indexed: 12/21/2022]
Abstract
The transcriptional regulator PRDM1 controls cell-fate decisions and has been implicated in human tumorigenesis as a tumor suppressor. However, its pathological role in glioma remains elusive. In this study, we showed that PRDM1 protein levels were inversely correlated with the pathological grade of gliomas and were predictive of patient survival in a retrospective analysis. Restored expression of PRDM1 inhibited proliferation and suppressed invasion by glioma cells. Mechanistic investigation revealed that PRDM1 attenuated glioma malignancy by negatively modulating Wnt/β-catenin signaling and this modulation was dependent on the Wnt inhibitor Dkk1. Using bioinformatics and biological approaches, we found that PRDM1 was a direct target of miR-30a-5p, and PRDM1 dysfunction was attributable to miR-30a-5p-mediated repression. Our results provide evidence that PRDM1 deficiency contributes to the phenotype maintenance and pathogenesis of gliomas.
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111
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Romagnoli M, Belguise K, Yu Z, Wang X, Landesman-Bollag E, Seldin DC, Chalbos D, Barillé-Nion S, Jézéquel P, Seldin ML, Sonenshein GE. Epithelial-to-mesenchymal transition induced by TGF-β1 is mediated by Blimp-1-dependent repression of BMP-5. Cancer Res 2012; 72:6268-78. [PMID: 23054396 DOI: 10.1158/0008-5472.can-12-2270] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Induction of epithelial-to-mesenchymal transition (EMT) by TGF-β1 requires Ras signaling. We recently identified the transcriptional repressor Blimp-1 (PRDM1) as a downstream effector of the NF-κB, RelB/Bcl-2/Ras-driven pathway that promotes breast cancer cell migration. As the RelB/Blimp-1 pathway similarly required Ras signaling activation, we tested whether Blimp-1 plays a role in TGF-β1-mediated EMT. Here, TGF-β1 treatment of untransformed NMuMG mammary epithelial and MDA-MB-231 breast cancer cells was shown to induce Blimp-1 expression, which promoted an EMT signature and cell migration. TGFB1 and BLIMP1 RNA levels were correlated in patient breast tumors. BLIMP1 gene transcription was activated by TGF-β1 via a c-Raf (RAF1) to AP-1 pathway. Blimp-1 induced expression of the EMT master regulator Snail (SNAI1) via repressing BMP-5, which inhibited Snail expression upon TGF-β1 treatment. Interestingly, a similar cascade was observed during postnatal mouse mammary gland development. RelB expression was detected early in pregnancy followed progressively by Blimp-1 and then Snail; whereas, BMP-5 levels were high in nulliparous and regressing glands. Finally, lower BMP5 RNA levels were detected in patient breast tumors versus normal tissues, and correlated with cancer recurrence. Thus, the Ras effector Blimp-1 plays an essential role in TGF-β1-induced EMT via repression of BMP-5 in breast cancer.
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Affiliation(s)
- Mathilde Romagnoli
- Department of Biochemistry, Tufts University School of Medicine, Boston, MA 02111, USA
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112
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Vrzalikova K, Woodman CBJ, Murray PG. BLIMP1α, the master regulator of plasma cell differentiation is a tumor supressor gene in B cell lymphomas. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2012; 156:1-6. [PMID: 22580854 DOI: 10.5507/bp.2012.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
AIMS The aim of this review was to summarize recent knowledge of the structure and function of a transcriptional repressor, B lymphocyte induced maturation protein 1 (BLIMP1) and its participation in the pathogenesis of B lymphomas. METHODS AND RESULTS This review summarizes the structure and function of BLIMP1, its major target genes and its role as a tumour suppressor in B cell lymphomas. We review our recent data implicating the loss of BLIMP1α as an important step in the pathogenesis of the Epstein-Barr virus (EBV) associated B cell lymphomas. CONCLUSIONS BLIMP1 is a transcriptional repressor essential for the differentiation of germinal centre (GC) B cells to plasma cells. The loss of BLIMP1 in GC B cells could contribute to the pathogenesis of EBV-associated lymphomas by preventing plasma cell differentiation and viral replication.
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Affiliation(s)
- Katerina Vrzalikova
- School of Cancer Sciences, University of Birmingham, Birmingham, United Kingdom.
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113
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Morgan MAJ, Mould AW, Li L, Robertson EJ, Bikoff EK. Alternative splicing regulates Prdm1/Blimp-1 DNA binding activities and corepressor interactions. Mol Cell Biol 2012; 32:3403-13. [PMID: 22733990 PMCID: PMC3422002 DOI: 10.1128/mcb.00174-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 06/16/2012] [Indexed: 01/14/2023] Open
Abstract
Prdm1/Blimp-1 is a master regulator of gene expression in diverse tissues of the developing embryo and adult organism. Its C-terminal zinc finger domain mediates nuclear import, DNA binding, and recruitment of the corepressors G9a and HDAC1/2. Alternatively spliced transcripts lacking exon 7 sequences encode a structurally divergent isoform (Blimp-1Δexon7) predicted to have distinct functions. Here we demonstrate that the short Blimp-1Δexon7 isoform lacks DNA binding activity and fails to bind G9a or HDAC1/2 but retains the ability to interact with PRMT5. To investigate functional roles of alternative splicing in vivo, we engineered novel mouse strains via embryonic stem (ES) cell technology. Like null mutants, embryos carrying a targeted deletion of exon 7 and exclusively expressing Blimp-1Δexon7 die at around embryonic day 10.5 (E10.5) due to placental defects. In heterozygous Δexon7 mice, there is no evidence of dominant-negative effects. Mice carrying a knock-in allele with an exon 6-exon 7 fusion express full-length Blimp-1 only, develop normally, are healthy and fertile as adults, and efficiently generate mature plasma cells. These findings strongly suggest that the short Blimp-1Δexon7 isoform is dispensable. We propose that developmentally regulated alternative splicing is influenced by chromatin structure at the locus and fine-tunes Blimp-1's functional capabilities.
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Affiliation(s)
- Marc A J Morgan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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114
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Adrianto I, Lin CP, Hale JJ, Levin AM, Datta I, Parker R, Adler A, Kelly JA, Kaufman KM, Lessard CJ, Moser KL, Kimberly RP, Harley JB, Iannuzzi MC, Rybicki BA, Montgomery CG. Genome-wide association study of African and European Americans implicates multiple shared and ethnic specific loci in sarcoidosis susceptibility. PLoS One 2012; 7:e43907. [PMID: 22952805 PMCID: PMC3428296 DOI: 10.1371/journal.pone.0043907] [Citation(s) in RCA: 90] [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: 02/24/2012] [Accepted: 07/27/2012] [Indexed: 12/21/2022] Open
Abstract
Sarcoidosis is a systemic inflammatory disease characterized by the formation of granulomas in affected organs. Genome-wide association studies (GWASs) of this disease have been conducted only in European population. We present the first sarcoidosis GWAS in African Americans (AAs, 818 cases and 1,088 related controls) followed by replication in independent sets of AAs (455 cases and 557 controls) and European Americans (EAs, 442 cases and 2,284 controls). We evaluated >6 million SNPs either genotyped using the Illumina Omni1-Quad array or imputed from the 1000 Genomes Project data. We identified a novel sarcoidosis-associated locus, NOTCH4, that reached genome-wide significance in the combined AA samples (rs715299, P(AA-meta) = 6.51 × 10(-10)) and demonstrated the independence of this locus from others in the MHC region in the same sample. We replicated previous European GWAS associations within HLA-DRA, HLA-DRB5, HLA-DRB1, BTNL2, and ANXA11 in both our AA and EA datasets. We also confirmed significant associations to the previously reported HLA-C and HLA-B regions in the EA but not AA samples. We further identified suggestive associations with several other genes previously reported in lung or inflammatory diseases.
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Affiliation(s)
- Indra Adrianto
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Chee Paul Lin
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Jessica J. Hale
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Albert M. Levin
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Indrani Datta
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Ryan Parker
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Adam Adler
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Jennifer A. Kelly
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Kenneth M. Kaufman
- Division of Rheumatology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- The United States Department of Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Christopher J. Lessard
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Kathy L. Moser
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Robert P. Kimberly
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - John B. Harley
- Division of Rheumatology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- The United States Department of Veterans Affairs Medical Center, Cincinnati, Ohio, United States of America
| | - Michael C. Iannuzzi
- Department of Medicine, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Benjamin A. Rybicki
- Department of Public Health Sciences, Henry Ford Health System, Detroit, Michigan, United States of America
| | - Courtney G. Montgomery
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
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115
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Hohenauer T, Moore AW. The Prdm family: expanding roles in stem cells and development. Development 2012; 139:2267-82. [PMID: 22669819 DOI: 10.1242/dev.070110] [Citation(s) in RCA: 184] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Members of the Prdm family are characterized by an N-terminal PR domain that is related to the SET methyltransferase domain, and multiple zinc fingers that mediate sequence-specific DNA binding and protein-protein interactions. Prdm factors either act as direct histone methyltransferases or recruit a suite of histone-modifying enzymes to target promoters. In this way, they function in many developmental contexts to drive and maintain cell state transitions and to modify the activity of developmental signalling pathways. Here, we provide an overview of the structure and function of Prdm family members and discuss the roles played by these proteins in stem cells and throughout development.
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Affiliation(s)
- Tobias Hohenauer
- Disease Mechanism Research Core, RIKEN Brain Science Institute, Wako, Saitama, 351-0198, Japan
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116
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Yu Z, Sato S, Trackman PC, Kirsch KH, Sonenshein GE. Blimp1 activation by AP-1 in human lung cancer cells promotes a migratory phenotype and is inhibited by the lysyl oxidase propeptide. PLoS One 2012; 7:e33287. [PMID: 22438909 PMCID: PMC3305320 DOI: 10.1371/journal.pone.0033287] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 02/10/2012] [Indexed: 01/04/2023] Open
Abstract
B lymphocyte-induced maturation protein 1 (Blimp1) is a master regulator of B cell differentiation, and controls migration of primordial germ cells. Recently we observed aberrant Blimp1 expression in breast cancer cells resulting from an NF-κB RelB to Ras signaling pathway. In order to address the question of whether the unexpected expression of Blimp1 is seen in other epithelial-derived tumors, we selected lung cancers as they are frequently driven by Ras signaling. Blimp1 was detected in all five lung cancer cell lines examined and shown to promote lung cancer cell migration and invasion. Interrogation of microarray datasets demonstrated elevated BLIMP1 RNA expression in lung adenocarcinoma, pancreatic ductal carcinomas, head and neck tumors as well as in glioblastomas. Involvement of Ras and its downstream kinase c-Raf was confirmed using mutant and siRNA strategies. We next addressed the issue of mechanism of Blimp1 activation in lung cancer. Using knockdown and ectopic expression, the role of the Activator Protein (AP)-1 family of transcription factors was demonstrated. Further, chromatin immunoprecipitation assays confirmed binding to identified AP-1 elements in the BLIMP1 promoter of ectopically expressed c-Jun and of endogenous AP-1 subunits following serum stimulation. The propeptide domain of lysyl oxidase (LOX-PP) was identified as a tumor suppressor, with ability to reduce Ras signaling in lung cancer cells. LOX-PP reduced expression of Blimp1 by binding to c-Raf and inhibiting activation of AP-1, thereby attenuating the migratory phenotype of lung cancer cells. Thus, Blimp1 is a mediator of Ras/Raf/AP-1 signaling that promotes cell migration, and is repressed by LOX-PP in lung cancer.
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Affiliation(s)
- Ziyang Yu
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Seiichi Sato
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Philip C. Trackman
- Division of Oral Biology, Boston University Henry M. Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Kathrin H. Kirsch
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Gail E. Sonenshein
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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117
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Fang TC, Schaefer U, Mecklenbrauker I, Stienen A, Dewell S, Chen MS, Rioja I, Parravicini V, Prinjha RK, Chandwani R, MacDonald MR, Lee K, Rice CM, Tarakhovsky A. Histone H3 lysine 9 di-methylation as an epigenetic signature of the interferon response. ACTA ACUST UNITED AC 2012; 209:661-9. [PMID: 22412156 PMCID: PMC3328357 DOI: 10.1084/jem.20112343] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Effective antiviral immunity depends on the ability of infected cells or cells triggered with virus-derived nucleic acids to produce type I interferon (IFN), which activates transcription of numerous antiviral genes. However, disproportionately strong or chronic IFN expression is a common cause of inflammatory and autoimmune diseases. We describe an epigenetic mechanism that determines cell type-specific differences in IFN and IFN-stimulated gene (ISG) expression in response to exogenous signals. We identify di-methylation of histone H3 at lysine 9 (H3K9me2) as a suppressor of IFN and IFN-inducible antiviral gene expression. We show that levels of H3K9me2 at IFN and ISG correlate inversely with the scope and amplitude of IFN and ISG expression in fibroblasts and dendritic cells. Accordingly, genetic ablation or pharmacological inactivation of lysine methyltransferase G9a, which is essential for the generation of H3K9me2, resulted in phenotypic conversion of fibroblasts into highly potent IFN-producing cells and rendered these cells resistant to pathogenic RNA viruses. In summary, our studies implicate H3K9me2 and enzymes controlling its abundance as key regulators of innate antiviral immunity.
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Affiliation(s)
- Terry C Fang
- Laboratory of Immune Cell Epigenetics and Signaling, Rockefeller University, New York, NY 10065, USA.
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118
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Josse T, Mokrani-Benhelli H, Benferhat R, Shestakova E, Mansuroglu Z, Kakanakou H, Billecocq A, Bouloy M, Bonnefoy E. Association of the interferon-β gene with pericentromeric heterochromatin is dynamically regulated during virus infection through a YY1-dependent mechanism. Nucleic Acids Res 2012; 40:4396-411. [PMID: 22287632 PMCID: PMC3378888 DOI: 10.1093/nar/gks050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Nuclear architecture as well as gene nuclear positioning can modulate gene expression. In this work, we have analyzed the nuclear position of the interferon-β (IFN-β) locus, responsible for the establishment of the innate antiviral response, with respect to pericentromeric heterochromatin (PCH) in correlation with virus-induced IFN-β gene expression. Experiments were carried out in two different cell types either non-infected (NI) or during the time course of three different viral infections. In NI cells, we showed a monoallelic IFN-β promoter association with PCH that strongly decreased after viral infection. Dissociation of the IFN-β locus away from these repressive regions preceded strong promoter transcriptional activation and was reversible within 12 h after infection. No dissociation was observed after infection with a virus that abnormally maintained the IFN-β gene in a repressed state. Dissociation induced after virus infection specifically targeted the IFN-β locus without affecting the general structure and nuclear distribution of PCH clusters. Using cell lines stably transfected with wild-type or mutated IFN-β promoters, we identified the proximal region of the IFN-β promoter containing YY1 DNA-binding sites as the region regulating IFN-β promoter association with PCH before as well as during virus infection.
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Affiliation(s)
- T Josse
- Régulation de la Transcription et Maladies Génétiques, CNRS FRE3235, Université Paris Descartes, 45 rue des Saints Pères, 75270, Paris cedex 06, France
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119
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Chevrier N, Mertins P, Artyomov MN, Shalek AK, Iannacone M, Ciaccio MF, Gat-Viks I, Tonti E, DeGrace MM, Clauser KR, Garber M, Eisenhaure TM, Yosef N, Robinson J, Sutton A, Andersen MS, Root DE, von Andrian U, Jones RB, Park H, Carr SA, Regev A, Amit I, Hacohen N. Systematic discovery of TLR signaling components delineates viral-sensing circuits. Cell 2012; 147:853-67. [PMID: 22078882 DOI: 10.1016/j.cell.2011.10.022] [Citation(s) in RCA: 151] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/27/2011] [Accepted: 10/17/2011] [Indexed: 12/30/2022]
Abstract
Deciphering the signaling networks that underlie normal and disease processes remains a major challenge. Here, we report the discovery of signaling components involved in the Toll-like receptor (TLR) response of immune dendritic cells (DCs), including a previously unkown pathway shared across mammalian antiviral responses. By combining transcriptional profiling, genetic and small-molecule perturbations, and phosphoproteomics, we uncover 35 signaling regulators, including 16 known regulators, involved in TLR signaling. In particular, we find that Polo-like kinases (Plk) 2 and 4 are essential components of antiviral pathways in vitro and in vivo and activate a signaling branch involving a dozen proteins, among which is Tnfaip2, a gene associated with autoimmune diseases but whose role was unknown. Our study illustrates the power of combining systematic measurements and perturbations to elucidate complex signaling circuits and discover potential therapeutic targets.
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Affiliation(s)
- Nicolas Chevrier
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
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120
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Siegel R, Eskdale J, Gallagher G. Regulation of IFN-λ1 promoter activity (IFN-λ1/IL-29) in human airway epithelial cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 187:5636-44. [PMID: 22058416 DOI: 10.4049/jimmunol.1003988] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The type III (λ) IFNs (IFN-λ1, IFN-λ2, and IFN-λ3) and their receptor are the most recently discovered IFN family. They are induced by viruses and mediate antiviral activity, but type III IFNs have an important, specific functional niche at the immune/epithelial interface, as well as in the regulation of Th2 cytokines. Their expression appears diminished in bronchial epithelial cells of rhinovirus-infected asthmatic individuals. We investigated the regulation of IFN-λ1 expression in human airway epithelial cells using reporter genes analysis, chromatin immunoprecipitation, small interfering RNA knockdown, and DNase footprinting. In this article, we define the c-REL/p65 NF-κB heterodimer and IRF-1 as key transcriptional activators and ZEB1, B lymphocyte-induced maturation protein 1, and the p50 NF-κB homodimer as key repressors of the IFN-λ1 gene. We further show that ZEB1 selectively regulates type III IFNs. To our knowledge, this study presents the first characterization of any type III IFN promoter in its native context and conformation in epithelial cells and can now be applied to understanding pathogenic dysregulation of IFN-λ1 in human disease.
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Affiliation(s)
- Rachael Siegel
- Genetic Immunology Laboratory, HUMIGEN LLC, Institute for Genetic Immunology, Genesis Biotechnology Group, Hamilton, NJ 08690, USA
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121
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Kim SJ, Zou YR, Goldstein J, Reizis B, Diamond B. Tolerogenic function of Blimp-1 in dendritic cells. ACTA ACUST UNITED AC 2011; 208:2193-9. [PMID: 21948081 PMCID: PMC3201204 DOI: 10.1084/jem.20110658] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Blimp-1 has been identified as a key regulator of plasma cell differentiation in B cells and effector/memory function in T cells. We demonstrate that Blimp-1 in dendritic cells (DCs) is required to maintain immune tolerance in female but not male mice. Female mice lacking Blimp-1 expression in DCs (DCBlimp-1(ko)) or haploid for Blimp-1 expression exhibit normal DC development but an altered DC function and develop lupus-like autoantibodies. Although DCs have been implicated in the pathogenesis of lupus, a defect in DC function has not previously been shown to initiate the disease process. Blimp-1(ko) DCs display increased production of IL-6 and preferentially induce differentiation of follicular T helper cells (T(FH) cells) in vitro. In vivo, the expansion of T(FH) cells is associated with an enhanced germinal center (GC) response and the development of autoreactivity. These studies demonstrate a critical role for Blimp-1 in the tolerogenic function of DCs and show that a diminished expression of Blimp-1 in DCs can result in aberrant activation of the adaptive immune system with the development of a lupus-like serology in a gender-specific manner. This study is of particular interest because a polymorphism of Blimp-1 associates with SLE.
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Affiliation(s)
- Sun Jung Kim
- Center for Autoimmune and Musculoskeletal Diseases, Feinstein Institute for Medical Research, Manhasset, NY 11030, USA
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122
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Harper J, Mould A, Andrews RM, Bikoff EK, Robertson EJ. The transcriptional repressor Blimp1/Prdm1 regulates postnatal reprogramming of intestinal enterocytes. Proc Natl Acad Sci U S A 2011; 108:10585-90. [PMID: 21670299 PMCID: PMC3127883 DOI: 10.1073/pnas.1105852108] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Female mammals produce milk to feed their newborn offspring before teeth develop and permit the consumption of solid food. Intestinal enterocytes dramatically alter their biochemical signature during the suckling-to-weaning transition. The transcriptional repressor Blimp1 is strongly expressed in immature enterocytes in utero, but these are gradually replaced by Blimp1(-) crypt-derived adult enterocytes. Here we used a conditional inactivation strategy to eliminate Blimp1 function in the developing intestinal epithelium. There was no noticeable effect on gross morphology or formation of mature cell types before birth. However, survival of mutant neonates was severely compromised. Transcriptional profiling experiments reveal global changes in gene expression patterns. Key components of the adult enterocyte biochemical signature were substantially and prematurely activated. In contrast, those required for processing maternal milk were markedly reduced. Thus, we conclude Blimp1 governs the developmental switch responsible for postnatal intestinal maturation.
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Affiliation(s)
- James Harper
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom; and
| | - Arne Mould
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom; and
| | - Robert M. Andrews
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton-Cambridge CB10 1SA, United Kingdom
| | - Elizabeth K. Bikoff
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom; and
| | - Elizabeth J. Robertson
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom; and
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123
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PR-domain-containing Mds1-Evi1 is critical for long-term hematopoietic stem cell function. Blood 2011; 118:3853-61. [PMID: 21666053 DOI: 10.1182/blood-2011-02-334680] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Mds1 and Evi1 complex locus (Mecom) gives rise to several alternative transcripts implicated in leukemogenesis. However, the contribution that Mecom-derived gene products make to normal hematopoiesis remains largely unexplored. To investigate the role of the upstream transcription start site of Mecom in adult hematopoiesis, we created a mouse model with a lacZ knock-in at this site, termed ME(m1), which eliminates Mds1-Evi1 (ME), the longer, PR-domain-containing isoform produced by the gene (also known as PRDM3). β-galactosidase-marking studies revealed that, within hematopoietic cells, ME is exclusively expressed in the stem cell compartment. ME deficiency leads to a reduction in the number of HSCs and a complete loss of long-term repopulation capacity, whereas the stem cell compartment is shifted from quiescence to active cycling. Genetic exploration of the relative roles of endogenous ME and EVI1 isoforms revealed that ME preferentially rescues long-term HSC defects. RNA-seq analysis in Lin(-)Sca-1(+)c-Kit(+) cells (LSKs) of ME(m1) documents near complete silencing of Cdkn1c, encoding negative cell-cycle regulator p57-Kip2. Reintroduction of ME into ME(m1) LSKs leads to normalization of both p57-Kip2 expression and growth control. Our results clearly demonstrate a critical role of PR-domain-containing ME in linking p57-kip2 regulation to long-term HSC function.
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124
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Ye J, Maniatis T. Negative regulation of interferon-β gene expression during acute and persistent virus infections. PLoS One 2011; 6:e20681. [PMID: 21677781 PMCID: PMC3108996 DOI: 10.1371/journal.pone.0020681] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 05/06/2011] [Indexed: 01/19/2023] Open
Abstract
The production of type I interferons (IFNs) in response to viral infections is critical for antiviral immunity. However, IFN production is transient, and continued expression can lead to inflammatory or autoimmune diseases. Thus, understanding the mechanisms underlying the negative regulation of IFN expression could lead to the development of novel therapeutic approaches to the treatment of these diseases. We report that the transcription factor IRF3 plays a central role in the negative regulation of interferon-β (IFNβ) expression during both acute and persistent (chronic) virus infections. We show that the degradation of IRF3 during acute infections, rather than the activation of transcriptional repressors, leads to the down regulation of IFNβ expression. We also show that the block to IFNβ expression in mouse embryonic fibroblasts that are persistently infected with Sendai virus (SeV) correlates with the absence of transcriptionally active IRF3. Remarkably, ongoing protein synthesis and viral replication are required to maintain repression of the IFNβ gene in persistently infected cells, as the gene can be activated by the protein synthesis inhibitor cycloheximide, or by the antiviral drug ribavirin. Finally, we show that the SeV V protein inhibits IRF3 activity in persistently infected cells. Thus, in conjunction with the known interference with STAT1 by the SeV C protein, both IFN activation and its signaling pathways are blocked in persistently infected cells. We conclude that the transcription factor IRF3 is targeted for turnover and inactivation through distinct mechanisms from both the host cells and virus, leading to the inhibition of IFNβ gene expression during acute and persistent viral infections. These observations show that IRF3 plays a critical role, not only in the activation of the IFNβ gene, but also in the controlling the duration of its expression. (284 words)
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Affiliation(s)
- Junqiang Ye
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Tom Maniatis
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail:
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125
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Horn KH, Warner DR, Pisano M, Greene RM. PRDM16 expression in the developing mouse embryo. Acta Histochem 2011; 113:150-5. [PMID: 19853285 DOI: 10.1016/j.acthis.2009.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 09/10/2009] [Accepted: 09/16/2009] [Indexed: 11/29/2022]
Abstract
PRDM16 is a member of the PR domain-containing protein family and is associated with various disease states including myelodysplastic syndrome and adult T-cell leukemia, as well as developmental abnormalities such as cleft palate. It is also known to act as a regulator of cell differentiation. Expression analysis of PRDM16 is limited, especially within the developing embryo. The current study evaluated the temporal and spatial localization of PRDM16 during early mouse development (embryonic days 8.5-14.5). PRDM16 was first detected on E9.5 in a limited number of tissues and by E14.5, was expressed in a broad range of developing tissues including those of the brain, lung, kidney, and gastrointestinal tract. The expression pattern is consistent with a role for PRDM16 in the development of multiple tissues. Collectively, these studies are the first to characterize the expression of the PRDM16 gene during early murine development.
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Affiliation(s)
- Kristin H Horn
- University of Louisville Birth Defects Center, Department of Molecular, Cellular and Craniofacial Biology, School of Dentistry, 501 South Preston Street, Louisville, KY 40292, USA
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126
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Ohtani M, Miyadai T. Functional analysis of fish BCL-6 and Blimp-1 in vitro: transcriptional repressors for B-cell terminal differentiation in fugu (Takifugu rubripes). Mol Immunol 2011; 48:818-25. [PMID: 21216469 DOI: 10.1016/j.molimm.2010.10.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 10/24/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
Abstract
The transcriptional repressors BCL-6 and Blimp-1 are key regulators of B-cell terminal differentiation in mammals. We have previously identified the BCL-6 gene and Blimp-1 gene in fugu (Takifugu rubripes). In the present report, we conducted a functional analysis of fugu BCL-6 and Blimp-1 by using a one-hybrid reporter assay with Gal4 fusion proteins and Gal4DBD luciferase reporter gene. Results from the reporter assays in mammalian cell lines (HeLa, HEK-293, CV-1 and NIH3T3) and the fish cell line EPC show that Gal4-BCL6 and Gal4-Blimp1 strongly repress the transcription of the luciferase gene in all cell lines. Furthermore, deletion analyses show that the N-terminal region of BCL-6 has transcriptional repression activity; the BTB/POZ domain is an especially potent repression domain. In contrast to BCL-6, although the N-acidic domain and PR domain are insufficient for repression, most functional motifs of Blimp-1 are associated with transcriptional repression. These results suggest that BCL-6 and Blimp-1 are functional transcriptional repressors in fugu and that they regulate B-cell terminal differentiation in fugu.
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Affiliation(s)
- Maki Ohtani
- Laboratory of Marine Biotechnology, Faculty of Marine Bioscience, Fukui Prefectural University, 1-1 Gakuen-Chou, Obama, Fukui 917-0003, Japan
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127
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Xin A, Nutt SL, Belz GT, Kallies A. Blimp1: driving terminal differentiation to a T. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 780:85-100. [PMID: 21842367 DOI: 10.1007/978-1-4419-5632-3_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
B lymphocyte maturation-induced protein-1 (Blimp1) is a transcriptional repressor expressed in diverse cell types. In the adaptive immune system, Blimp1 is expressed in lymphocytes that have undergone effector differentiation. Blimp1 is a master regulator of plasma cell differentiation and plays important roles in controlling T cell homeostasis and effector differentiation. Blimp1 can be induced by a variety of cytokines including IL-2, IL-4, IL-12, and IL-21 in addition to TCR and co-stimulatory signals. Blimp1-deficient mice develop spontaneous inflammatory disease mediated by infiltration of activated T cells into tissues. During immune responses Blimp1 is required for the differentiation of plasma cells as well as short-lived CD8(+) cytotoxic T cells. Mounting evidence suggests that Blimp1 plays a common role in the terminal differentiation of multiple cell subsets.
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128
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Sulentic CEW, Kaminski NE. The long winding road toward understanding the molecular mechanisms for B-cell suppression by 2,3,7,8-tetrachlorodibenzo-p-dioxin. Toxicol Sci 2010; 120 Suppl 1:S171-91. [PMID: 20952503 DOI: 10.1093/toxsci/kfq324] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Suppression of humoral immune responses by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was first reported in the mid-1970s. Since this initial observation, much effort has been devoted by many laboratories toward elucidation of the cellular and molecular mechanisms responsible for the profound impairment of humoral immune responses by TCDD, which is characterized by decreased B cell to plasma cell differentiation and suppression of immunoglobulin production. These efforts have led to a significant body of research demonstrating a direct effect of TCDD on B-cell maturation and function as well as a requisite but as yet undefined role of the aryl hydrocarbon receptor (AhR) in these effects. Likewise, a number of molecular targets putatively involved in mediating B-cell dysfunction by TCDD, and other AhR ligands, have been identified. However, our current understanding has primarily relied on findings from mouse models, and the translation of this knowledge to effects on human B cells and humoral immunity in humans is less clear. Therefore, a current challenge is to determine how TCDD and the AhR affect human B cells. Efforts have been made in this direction but continued progress in developing adequate human models is needed. An in-depth discussion of these advances and limitations in elucidating the cellular and molecular mechanisms putatively involved in the suppression of B-cell function by TCDD as well as the implications on human diseases associated in epidemiological studies with exposure to TCDD and dioxin-like compounds is the primary focus of this review.
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Affiliation(s)
- Courtney E W Sulentic
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
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129
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Smith MA, Maurin M, Cho HI, Becknell B, Freud AG, Yu J, Wei S, Djeu J, Celis E, Caligiuri MA, Wright KL. PRDM1/Blimp-1 controls effector cytokine production in human NK cells. THE JOURNAL OF IMMUNOLOGY 2010; 185:6058-67. [PMID: 20944005 DOI: 10.4049/jimmunol.1001682] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
NK cells are major effectors of the innate immune response through cytolysis and bridge to the adaptive immune response through cytokine release. The mediators of activation are well studied; however, little is known about the mechanisms that restrain activation. In this report, we demonstrate that the transcriptional repressor PRDM1 (also known as Blimp-1 or PRDI-BF1) is a critical negative regulator of NK function. Three distinct PRDM1 isoforms are selectively induced in the CD56(dim) NK population in response to activation. PRDM1 coordinately suppresses the release of IFN-γ, TNF-α, and TNF-β through direct binding to multiple conserved regulatory regions. Ablation of PRDM1 expression leads to enhanced production of IFN-γ and TNF-α but does not alter cytotoxicity, whereas overexpression blocks cytokine production. PRDM1 response elements are defined at the IFNG and TNF loci. Collectively, these data demonstrate a key role for PRDM1 in the negative regulation of NK activation and position PRDM1 as a common regulator of the adaptive and innate immune response.
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Affiliation(s)
- Matthew A Smith
- H. Lee Moffitt Cancer Center and Research Institute, University of South Florida, Tampa, FL 33612, USA
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130
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Doody GM, Care MA, Burgoyne NJ, Bradford JR, Bota M, Bonifer C, Westhead DR, Tooze RM. An extended set of PRDM1/BLIMP1 target genes links binding motif type to dynamic repression. Nucleic Acids Res 2010; 38:5336-50. [PMID: 20421211 PMCID: PMC2938208 DOI: 10.1093/nar/gkq268] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 03/11/2010] [Accepted: 03/30/2010] [Indexed: 11/14/2022] Open
Abstract
The transcriptional repressor B lymphocyte-induced maturation protein-1 (BLIMP1) regulates gene expression and cell fate. The DNA motif bound by BLIMP1 in vitro overlaps with that of interferon regulatory factors (IRFs), which respond to inflammatory/immune signals. At such sites, BLIMP1 and IRFs can antagonistically regulate promoter activity. In vitro motif selection predicts that only a subset of BLIMP1 or IRF sites is subject to antagonistic regulation, but the extent to which antagonism occurs is unknown, since an unbiased assessment of BLIMP1 occupancy in vivo is lacking. To address this, we identified an extended set of promoters occupied by BLIMP1. Motif discovery and enrichment analysis demonstrate that multiple motif variants are required to capture BLIMP1 binding specificity. These are differentially associated with CpG content, leading to the observation that BLIMP1 DNA-binding is methylation sensitive. In occupied promoters, only a subset of BLIMP1 motifs overlap with IRF motifs. Conversely, a distinct subset of IRF motifs is not enriched amongst occupied promoters. Genes linked to occupied promoters containing overlapping BLIMP1/IRF motifs (e.g. AIM2, SP110, BTN3A3) are shown to constitute a dynamic target set which is preferentially activated by BLIMP1 knock-down. These data confirm and extend the competitive model of BLIMP1 and IRF interaction.
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Affiliation(s)
- Gina M. Doody
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - Matthew A. Care
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - Nicholas J. Burgoyne
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - James R. Bradford
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - Maria Bota
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - Constanze Bonifer
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - David R. Westhead
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
| | - Reuben M. Tooze
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, Bioinformatics Group, Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and Applied Computational Biology and Bioinformatics, Paterson Institute of Cancer Research, University of Manchester, Manchester, UK
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131
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Affiliation(s)
- Kathryn Calame
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
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132
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Flesher DLT, Sun X, Behrens TW, Graham RR, Criswell LA. Recent advances in the genetics of systemic lupus erythematosus. Expert Rev Clin Immunol 2010; 6:461-79. [PMID: 20441431 DOI: 10.1586/eci.10.8] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the production of antinuclear autoantibodies and the inflammatory infiltration of many organ systems. SLE is a complex disorder in which multiple genetic variants, together with environmental and hormonal factors, contribute to disease risk. In this article, we summarize our current understanding of the genetic contribution to SLE in light of recent genome-wide association studies, which have brought the total number of confirmed SLE susceptibility loci to 29. In the second section, we explore the functional implications of these risk loci and, in particular, highlight the role that many of these genes play in the Toll-like receptor and type I interferon signaling pathways. Finally, we discuss the genetic overlap between SLE and other autoimmune and inflammatory conditions as several risk loci are shared among multiple disorders, suggesting common underlying pathogenic mechanisms.
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Affiliation(s)
- Donna L Thibault Flesher
- ITGR Human Genetics, Genentech Research & Early Development, 1 DNA Way, South San Francisco, CA 94080-94990, USA
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133
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Blimp1 suppresses Chx10 expression in differentiating retinal photoreceptor precursors to ensure proper photoreceptor development. J Neurosci 2010; 30:6515-26. [PMID: 20463215 DOI: 10.1523/jneurosci.0771-10.2010] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The zinc finger transcription factor Blimp1 plays fundamentally important roles in many cell lineages and in the early development of several cell types, including B and T lymphocytes and germ cells. Although Blimp1 expression in developing retinal photoreceptor cells has been reported, its function remains unclear. We identified Blimp1 as a downstream factor of Otx2, which plays an essential role in photoreceptor cell fate determination. To investigate Blimp1 function in the mouse retina, we ablated Blimp1 in the developing retina by conditional gene targeting. In the Blimp1 conditional knockout (CKO) retina, the number of photoreceptor cells was markedly reduced in the differentiated retina. We found that the numbers of both bipolar-like cells and proliferating retinal cells increased noticeably, with ectopic localizations in the postnatal developing retina. In contrast, a reduction of the number of photoreceptor precursors was observed during development. Forced expression of Blimp1 by in vivo electroporation suppressed bipolar cell genesis in the developing retina. Multiple genes involved in bipolar development, including Chx10, were upregulated in the Blimp1 CKO retina. Furthermore, we showed that Blimp1 can bind to the Chx10 enhancer and repress Chx10 enhancer activity. These results suggest that Blimp1 plays a crucial role in photoreceptor development by repressing genes involved in bipolar cell fate specification and retinal cell proliferation in differentiating photoreceptor precursors.
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134
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Miyauchi Y, Ninomiya K, Miyamoto H, Sakamoto A, Iwasaki R, Hoshi H, Miyamoto K, Hao W, Yoshida S, Morioka H, Chiba K, Kato S, Tokuhisa T, Saitou M, Toyama Y, Suda T, Miyamoto T. The Blimp1-Bcl6 axis is critical to regulate osteoclast differentiation and bone homeostasis. ACTA ACUST UNITED AC 2010; 207:751-62. [PMID: 20368579 PMCID: PMC2856022 DOI: 10.1084/jem.20091957] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Controlling osteoclastogenesis is critical to maintain physiological bone homeostasis and prevent skeletal disorders. Although signaling activating nuclear factor of activated T cells 1 (NFATc1), a transcription factor essential for osteoclastogenesis, has been intensively investigated, factors antagonistic to NFATc1 in osteoclasts have not been characterized. Here, we describe a novel pathway that maintains bone homeostasis via two transcriptional repressors, B cell lymphoma 6 (Bcl6) and B lymphocyte–induced maturation protein-1 (Blimp1). We show that Bcl6 directly targets ‘osteoclastic’ molecules such as NFATc1, cathepsin K, and dendritic cell-specific transmembrane protein (DC-STAMP), all of which are targets of NFATc1. Bcl6-overexpression inhibited osteoclastogenesis in vitro, whereas Bcl6-deficient mice showed accelerated osteoclast differentiation and severe osteoporosis. We report that Bcl6 is a direct target of Blimp1 and that mice lacking Blimp1 in osteoclasts exhibit osteopetrosis caused by impaired osteoclastogenesis resulting from Bcl6 up-regulation. Indeed, mice doubly mutant in Blimp1 and Bcl6 in osteoclasts exhibited decreased bone mass with increased osteoclastogenesis relative to osteoclast-specific Blimp1-deficient mice. These results reveal a Blimp1–Bcl6–osteoclastic molecule axis, which critically regulates bone homeostasis by controlling osteoclastogenesis and may provide a molecular basis for novel therapeutic strategies.
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Affiliation(s)
- Yoshiteru Miyauchi
- Department of Orthopedic Surgery, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
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135
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Abstract
IFN-regulatory factor 5 (IRF-5), a member of the IRF family, is a transcription factor that has a key role in the induction of the antiviral and inflammatory response. When compared with C57BL/6 mice, Irf5(-/-) mice show higher susceptibility to viral infection and decreased serum levels of type I IFN and the inflammatory cytokines IL-6 and TNF-alpha. Here, we demonstrate that IRF-5 is involved in B-cell maturation and the stimulation of Blimp-1 expression. The Irf5(-/-) mice develop an age-related splenomegaly, associated with a dramatic accumulation of CD19(+)B220(-) B cells and a disruption of normal splenic architecture. Splenic B cells from Irf5(-/-) mice also exhibited a decreased level of plasma cells. The CD19(+) Irf5(-/-) B cells show a defect in Toll-like receptor (TLR) 7- and TLR9-induced IL-6 production, and the aged Irf5(-/-) mice have decreased serum levels of natural antibodies; however, the antigen-specific IgG1 primary response was already dependent in IRF-5 in young mice, although the IgM response was not. Analysis of the profile of transcription factors associated with plasma cell differentiation shows down-regulation of Blimp-1 expression, a master regulator of plasma cell differentiation, which can be reconstituted with ectopic IRF-5. IRF-5 stimulates transcription of the Prdm1 gene encoding Blimp-1 and binds to the IRF site in the Prdm1 promoter. Collectively, these results reveal that the age-related splenomegaly in Irf5(-/-) mice is associated with an accumulation of CD19(+)B220(-) B cells with impaired functions and show the role of IRF-5 in the direct regulation of the plasma cell commitment factor Blimp-1 and in B-cell terminal differentiation.
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136
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Hangaishi A, Kurokawa M. Blimp-1 is a tumor suppressor gene in lymphoid malignancies. Int J Hematol 2010; 91:46-53. [DOI: 10.1007/s12185-009-0472-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 12/02/2009] [Accepted: 12/10/2009] [Indexed: 01/18/2023]
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137
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Cameron RA, Davidson EH. Flexibility of transcription factor target site position in conserved cis-regulatory modules. Dev Biol 2009; 336:122-35. [DOI: 10.1016/j.ydbio.2009.09.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 09/09/2009] [Accepted: 09/10/2009] [Indexed: 10/20/2022]
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138
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Chan YH, Chiang MF, Tsai YC, Su ST, Chen MH, Hou MS, Lin KI. Absence of the transcriptional repressor Blimp-1 in hematopoietic lineages reveals its role in dendritic cell homeostatic development and function. THE JOURNAL OF IMMUNOLOGY 2009; 183:7039-46. [PMID: 19915049 DOI: 10.4049/jimmunol.0901543] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Dendritic cells (DCs) are important for the initiation and regulation of immune responses. In this study, we demonstrate that DC homeostatic development in peripheral lymphoid organs is negatively regulated by the transcriptional repressor, Blimp-1, which is critical for regulation of plasma cell differentiation and T cell homeostasis and function. Deletion of Prdm1, the gene encoding Blimp-1, in mouse hematopoietic lineages resulted in an increase in the steady-state number of conventional DCs (cDCs). Specifically, Prdm1 deletion increased immediate CD8(-) cDC precursors in peripheral lymphoid organs, causing selective expansion of the CD8(-) cDC population. Upon stimulus-induced maturation, Blimp-1 was up-regulated in bone marrow-derived DCs via the p38 MAPK and NF-kappaB pathways. Notably, Blimp-1-deficient DCs matured poorly upon stimulation in vitro and in vivo. Blimp-1 binds to the proinflammatory cytokine/chemokine genes, Il-6 and Ccl2, and negatively regulates their expression. Collectively, our findings reveal two new roles for Blimp-1: negative regulation of a select subset of cDCs during homeostatic development, and enhancement of DC maturation.
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Affiliation(s)
- Yueh-Hsuan Chan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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139
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Morgan MAJ, Magnusdottir E, Kuo TC, Tunyaplin C, Harper J, Arnold SJ, Calame K, Robertson EJ, Bikoff EK. Blimp-1/Prdm1 alternative promoter usage during mouse development and plasma cell differentiation. Mol Cell Biol 2009; 29:5813-27. [PMID: 19737919 PMCID: PMC2772737 DOI: 10.1128/mcb.00670-09] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Revised: 07/11/2009] [Accepted: 08/22/2009] [Indexed: 12/14/2022] Open
Abstract
The zinc-finger PR domain transcriptional repressor Blimp-1/Prdm1 plays essential roles in primordial germ cell specification, placental, heart, and forelimb development, plasma cell differentiation, and T-cell homeostasis. The present experiments demonstrate that the mouse Prdm1 gene has three alternative promoter regions. All three alternative first exons splice directly to exon 3, containing the translational start codon. To examine possible cell-type-specific functional activities in vivo, we generated targeted deletions that selectively eliminate two of these transcriptional start sites. Remarkably, mice lacking the previously described first exon develop normally and are fertile. However, this region contains NF-kappaB binding sites, and as shown here, NF-kappaB signaling is required for Prdm1 induction. Thus, mutant B cells fail to express Prdm1 in response to lipopolysaccharide stimulation and lack the ability to become antibody-secreting cells. An alternative distal promoter located approximately 70 kb upstream, giving rise to transcripts strongly expressed in the yolk sac, is dispensable. Thus, the deletion of exon 1B has no noticeable effect on expression levels in the embryo or adult tissues. Collectively, these experiments provide insight into the organization of the Prdm1 gene and demonstrate that NF-kappaB is a key mediator of Prdm1 expression.
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Affiliation(s)
- Marc A. J. Morgan
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Erna Magnusdottir
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Tracy C. Kuo
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Chai Tunyaplin
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - James Harper
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Sebastian J. Arnold
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Kathryn Calame
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Elizabeth J. Robertson
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
| | - Elizabeth K. Bikoff
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom, Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032
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140
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Barnes NA, Stephenson SJ, Tooze RM, Doody GM. Amino acid deprivation links BLIMP-1 to the immunomodulatory enzyme indoleamine 2,3-dioxygenase. THE JOURNAL OF IMMUNOLOGY 2009; 183:5768-77. [PMID: 19828629 DOI: 10.4049/jimmunol.0803480] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Catabolism of tryptophan by IDO1 plays an important role in the control of immune responses. Activation of the eukaryotic initiation factor 2alpha (eIF2alpha) kinase general control nonderepressible-2 (GCN2) following tryptophan depletion is a major pathway mediating this effect. However, immunomodulatory target genes of GCN2 activation are poorly defined. The transcriptional repressor B lymphocyte-induced maturation protein-1 (BLIMP-1) is a target of the eIF2alpha kinase1, protein kinase-like ER kinase (PERK) during the unfolded protein response of the endoplasmic reticulum. Thus, BLIMP-1 might also be a mediator of the GCN2 stress response pathway activated by IDO1 and tryptophan depletion. Indeed, in human monocytes BLIMP-1 mRNA and protein are up-regulated in response to both a pharmacological activator of GCN2 and tryptophan-depletion generated by IDO1-transfected cells. This suggests a functional role for BLIMP-1 in the immunomodulatory effects of the IDO1-GCN2 axis. BLIMP-1 has been shown to repress IFN-gamma-regulated promoters. As IDO1 is itself highly responsive to IFN-gamma, we hypothesized that BLIMP-1 functions in a feedback loop to regulate IDO1 expression. We found that BLIMP-1 binds to IFN-responsive sites in the IDO1 promoter and represses IFN-dependent IDO1 activation. We propose that BLIMP-1 acts in a negative feedback loop to successfully balance the outcome of tolerance vs inflammation.
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Affiliation(s)
- Nicholas A Barnes
- Section of Experimental Haematology, Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, United Kingdom
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141
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Desai S, Bolick SCE, Maurin M, Wright KL. PU.1 regulates positive regulatory domain I-binding factor 1/Blimp-1 transcription in lymphoma cells. THE JOURNAL OF IMMUNOLOGY 2009; 183:5778-87. [PMID: 19828640 DOI: 10.4049/jimmunol.0901120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The human positive regulatory domain I-binding factor 1 (PRDI-BF1) and its murine homolog Blimp-1 promote differentiation of mature B cells into Ab-secreting plasma cells. In contrast, ectopic expression of PRDI-BF1 in lymphoma cells can lead to inhibition of proliferation or apoptosis. However, little is currently known about the regulation of PRDM1, the gene encoding PRDI-BF1. This report establishes that in lymphoma cells stimulation through the BCR rapidly induces endogenous PRDM1 at the level of transcription with minor changes in mRNA stability. The induced PRDM1-encoded protein localizes to its target genes in vivo and suppresses their expression. In vivo genomic footprinting of the PRDM1 promoter in unstimulated lymphoma and myeloma cells reveals multiple common in vivo occupied elements throughout the promoter. Further functional and structural analysis of the promoter reveals that the promoter is preloaded and poised for activation in the B cell lines. The transcription factor PU.1 is shown to be required for the BCR-induced expression of PRDM1 in lymphoma cells and in PU.1-positive myeloma cells. Activation of PRDM1 is associated with loss of the corepressor transducin-like enhancer of split 4 from the PU.1 complex. These findings indicate that PRDM1 is poised for activation in lymphoma cells and therefore may be a potential therapeutic target to inhibit lymphoma cell proliferation and survival.
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Affiliation(s)
- Shruti Desai
- H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
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142
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Bikoff EK, Morgan MA, Robertson EJ. An expanding job description for Blimp-1/PRDM1. Curr Opin Genet Dev 2009; 19:379-85. [PMID: 19592232 DOI: 10.1016/j.gde.2009.05.005] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 05/19/2009] [Accepted: 05/19/2009] [Indexed: 12/13/2022]
Abstract
The master transcriptional regulator Blimp-1/PRDM1 contains an N-terminal PR/SET domain and five C2H2 zinc fingers located near its C-terminus that mediate DNA binding, nuclear import and recruitment of histone modifying enzymes. These activities account for its ability to control cell-fate decisions in the embryo and govern tissue homeostasis in multiple cell types in the adult organism. New experiments demonstrate an increasing degree of complexity associated with Blimp-1/PRDM1 target site selection and its associations with epigenetic modifiers. Our current understanding of how this single unique species within the family of structurally similar PRDM proteins regulates gene expression patterns and governs developmental programmes in different cell lineages is discussed.
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Affiliation(s)
- Elizabeth K Bikoff
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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143
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Beuten J, Gelfond JAL, Martinez-Fierro ML, Weldon KS, Crandall AC, Rojas-Martinez A, Thompson IM, Leach RJ. Association of chromosome 8q variants with prostate cancer risk in Caucasian and Hispanic men. Carcinogenesis 2009; 30:1372-9. [PMID: 19528667 DOI: 10.1093/carcin/bgp148] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Genotyping of a 615 kb region within 8q24 with 49 haplotype-tagged single-nucleotide polymorphisms (SNPs) in 2109 samples (797 cases and 1312 controls) of two ethnic/racial groups found SNPs that are significantly associated with the risk for prostate cancer (PCa). The highest significance in Caucasian men was found for rs6983267; the AA genotype reduced the risk for PCa [odds ratio (OR) = 0.48, 95% confidence interval (CI) = 0.35-0.65, P = 2.74 x 10(-6)]. This SNP also had a significant independent effect from other SNPs in the region in this group. In Hispanic men, rs7837328 and rs921146 showed independent effects (OR = 2.55, 95% CI = 1.51-4.31, P = 4.33 x 10(-4), OR = 2.09, 95% CI = 1.40-3.12, P = 3.13 x 10(-4), respectively). Significant synergist effects for increasing numbers of high-risk alleles were found in both ethnicities. Haplotype analysis revealed major haplotypes, containing the non-risk alleles, conferred protection against PCa. We found high linkage disequilibrium between significant SNPs within the region and SNPs within the CUB and Sushi Multiple Domains 1 gene (CSMD1), on the short arm of chromosome 8 in both ethnicities. These data suggest that multiple interacting SNPs within 8q24, as well as different regions on chromosome 8 far beyond this 8q24 candidate region, may confer increased risk of PCa. This is the first report to investigate the involvement of 8q24 variants in the susceptibility for PCa in Hispanic men.
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Affiliation(s)
- Joke Beuten
- Department of Pediatrics, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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144
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RelB NF-kappaB represses estrogen receptor alpha expression via induction of the zinc finger protein Blimp1. Mol Cell Biol 2009; 29:3832-44. [PMID: 19433448 DOI: 10.1128/mcb.00032-09] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Aberrant constitutive expression of NF-kappaB subunits, reported in more than 90% of breast cancers and multiple other malignancies, plays pivotal roles in tumorigenesis. Higher RelB subunit expression was demonstrated in estrogen receptor alpha (ERalpha)-negative breast cancers versus ERalpha-positive ones, due in part to repression of RelB synthesis by ERalpha signaling. Notably, RelB promoted a more invasive phenotype in ERalpha-negative cancers via induction of the BCL2 gene. We report here that RelB reciprocally inhibits ERalpha synthesis in breast cancer cells, which contributes to a more migratory phenotype. Specifically, RelB is shown for the first time to induce expression of the zinc finger repressor protein Blimp1 (B-lymphocyte-induced maturation protein), the critical mediator of B- and T-cell development, which is transcribed from the PRDM1 gene. Blimp1 protein repressed ERalpha (ESR1) gene transcription. Commensurately higher Blimp1/PRDM1 expression was detected in ERalpha-negative breast cancer cells and primary breast tumors. Induction of PRDM1 gene expression was mediated by interaction of Bcl-2, localized in the mitochondria, with Ras. Thus, the induction of Blimp1 represents a novel mechanism whereby the RelB NF-kappaB subunit mediates repression, specifically of ERalpha, thereby promoting a more migratory phenotype.
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145
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Lord CA, Savitsky D, Sitcheran R, Calame K, Wright JR, Ting JPY, Williams KL. Blimp-1/PRDM1 mediates transcriptional suppression of the NLR gene NLRP12/Monarch-1. THE JOURNAL OF IMMUNOLOGY 2009; 182:2948-58. [PMID: 19234190 DOI: 10.4049/jimmunol.0801692] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
NLR (nucleotide-binding domain, leucine-rich repeat) proteins are intracellular regulators of host defense and immunity. One NLR gene, NLRP12 (NLR family, pyrin domain containing 12)/Monarch-1, has emerged as an important inhibitor of inflammatory gene expression in human myeloid cells. This is supported by genetic analysis linking the loss of a functional NLRP12 protein to hereditary periodic fever. NLRP12 transcription is diminished by specific TLR stimulation and myeloid cell maturation, consistent with its role as a negative regulator of inflammation. The NLRP12 promoter contains a novel Blimp-1 (B lymphocyte-induced maturation protein-1)/PRDM1 (PR domain-containing 1, with ZNF domain) binding site, and Blimp-1 reduces NLRP12 promoter activity, expression, and histone 3 acetylation. Blimp-1 associates with the endogenous NLRP12 promoter in a TLR-inducible manner and mediates the down-regulation of NLRP12 expression by TLR agonists. As expected, the expression of NLRP12 and Blimp-1 is inversely correlated. Analysis of Blimp-1(-/-) murine myeloid cells provides physiologic evidence that Blimp-1 reduces NLRP12 gene expression during cell differentiation. This demonstrates a novel role for Blimp-1 in the regulation of an NLR gene.
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Affiliation(s)
- Christopher A Lord
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
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146
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John SA, Garrett-Sinha LA. Blimp1: a conserved transcriptional repressor critical for differentiation of many tissues. Exp Cell Res 2008; 315:1077-84. [PMID: 19073176 DOI: 10.1016/j.yexcr.2008.11.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 11/21/2008] [Accepted: 11/23/2008] [Indexed: 02/03/2023]
Abstract
B lymphocyte induced maturation protein 1 (Blimp1) is a zinc finger transcriptional repressor whose function as a master regulator of terminal differentiation of B cells into plasma cells has long been studied and is well established. Recent studies have identified novel roles for Blimp1 including homeostasis of effector T cells, specification of primordial germ cells in mouse, specification of muscle fiber type in zebrafish and as a tumor suppressor gene in germinal center derived B cells. Blimp1 associates with a multitude of chromatin modifying enzymes inducing epigenetic changes at specific targets to regulate these diverse cell fates. In this review, we focus on the novel and emerging roles of Blimp1 in multiple tissues, on mechanisms of transcriptional repression by Blimp1 and on the activity of Blimp1 as a tumor suppressor.
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Affiliation(s)
- Shinu A John
- Department of Biochemistry, Center for Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, Buffalo, NY 14203, USA
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147
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Recurrent inactivation of the PRDM1 gene in primary central nervous system lymphoma. J Neuropathol Exp Neurol 2008; 67:720-7. [PMID: 18596541 DOI: 10.1097/nen.0b013e31817dd02d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Primary lymphomas of the CNS (PCNSLs) show molecular features of the late germinal center exit B-cell phenotype and are impaired in their terminal differentiation as indicated by a lack of immunoglobulin class switching. Because the positive regulatory domain I protein with ZNF domain (PRDM1/BLIMP1) is a master regulator of terminal B-cell differentiation into plasma cells, we investigated a series of 21 PCNSLs for the presence of mutations in the PRDM1 gene and alterations in the expression pattern of the PRDM1 protein. Direct sequencing of all coding exons of the PRDM1 gene identified deleterious mutations associated with abrogation of PRDM1 protein expression in 4 of 21 (19%) PCNSLs. Thus, similar to systemic diffuse large B-cell lymphomas, PRDM1 may be a tumor suppressor in some PCNSL and contribute to lymphomagenesis by impairing terminal differentiation.
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148
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Mora-López F, Pedreño-Horrillo N, Delgado-Pérez L, Brieva JA, Campos-Caro A. Transcription of PRDM1, the master regulator for plasma cell differentiation, depends on an SP1/SP3/EGR-1 GC-box. Eur J Immunol 2008; 38:2316-24. [PMID: 18604866 DOI: 10.1002/eji.200737861] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The positive regulatory domain containing 1, encoded by the PRDM1 gene, is a transcriptional repressor considered as a master regulator that is required and sufficient for plasma cell differentiation. In the present study we have performed sequence analysis of the upstream region of the human PRDM1 gene to detect the minimal promoter region necessary for PRDM1 gene transcription. This region comprises the region upstream of the initiation site, as well as the first exon. Collectively, deletion and mutation analysis in conjunction with luciferase reporter assays, EMSA and supershift assays identified a phylogenetically conserved GC-box as an essential element for PRDM1 expression. This GC-box element matches to a binding site for multiple transcription factors such as SP1 and SP3 isoforms as well as early growth response 1. Chromatin immunoprecipitation assays confirmed the in vivo binding capability of these factors to the human PRDM1 promoter. These studies together characterize for the first time the basal activity of the human PRDM1 promoter, through which several factors, including SP1, SP3 and early growth response 1, modulate its expression through a conserved GC-box.
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Abstract
B lymphocyte-induced maturation protein-1 (Blimp-1), discovered 16 years ago as a transcriptional repressor of the IFNbeta promoter, plays fundamentally important roles in many cell lineages and in early development. This review focuses on Blimp-1 in lymphocytes. In the B cell lineage, Blimp-1 is required for development of immunoglobulin-secreting cells and for maintenance of long-lived plasma cells (LLPCs). Direct targets of Blimp-1 and the transcriptional cascades Blimp-1 initiates to trigger plasmacytic differentiation are described. Blimp-1 also affects the homeostasis and function of CD4(+), CD8(+), and regulatory CD4(+) T cells, and Blimp-1 levels are highest in antigen-experienced T cells. Blimp-1 attenuates T cell proliferation and survival and modulates differentiation. Roles for Blimp-1 in Th1/Th2 specification, regulatory T cell function, and CD8 differentiation and function are under investigation. Signals that induce Blimp-1 in B cells include Toll-like receptor ligands and cytokines; in T cells, T cell receptors and cytokines induce Blimp-1. In spite of some commonalities, different targets and regulators of Blimp-1 in B and T cells suggest intriguing evolutionary divergence of this regulatory machinery.
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Affiliation(s)
- Gislâine Martins
- Department of Microbiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
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150
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Prdm1- and Sox6-mediated transcriptional repression specifies muscle fibre type in the zebrafish embryo. EMBO Rep 2008; 9:683-9. [PMID: 18535625 PMCID: PMC2424280 DOI: 10.1038/embor.2008.73] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 03/20/2008] [Accepted: 04/02/2008] [Indexed: 11/20/2022] Open
Abstract
The zebrafish u-boot (ubo) gene encodes the transcription factor Prdm1, which is essential for the specification of the primary slow-twitch muscle fibres that derive from adaxial cells. Here, we show that Prdm1 functions by acting as a transcriptional repressor and that slow-twitch-specific muscle gene expression is activated by Prdm1-mediated repression of the transcriptional repressor Sox6. Genes encoding fast-specific isoforms of sarcomeric proteins are ectopically expressed in the adaxial cells of ubotp39 mutant embryos. By using chromatin immunoprecipitation, we show that these are direct targets of Prdm1. Thus, Prdm1 promotes slow-twitch fibre differentiation by acting as a global repressor of fast-fibre-specific genes, as well as by abrogating the repression of slow-fibre-specific genes.
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