1
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Inge M, Miller R, Hook H, Bray D, Keenan J, Zhao R, Gilmore T, Siggers T. Rapid profiling of transcription factor-cofactor interaction networks reveals principles of epigenetic regulation. Nucleic Acids Res 2024; 52:10276-10296. [PMID: 39166482 PMCID: PMC11417405 DOI: 10.1093/nar/gkae706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/14/2024] [Accepted: 08/19/2024] [Indexed: 08/23/2024] Open
Abstract
Transcription factor (TF)-cofactor (COF) interactions define dynamic, cell-specific networks that govern gene expression; however, these networks are understudied due to a lack of methods for high-throughput profiling of DNA-bound TF-COF complexes. Here, we describe the Cofactor Recruitment (CoRec) method for rapid profiling of cell-specific TF-COF complexes. We define a lysine acetyltransferase (KAT)-TF network in resting and stimulated T cells. We find promiscuous recruitment of KATs for many TFs and that 35% of KAT-TF interactions are condition specific. KAT-TF interactions identify NF-κB as a primary regulator of acutely induced histone 3 lysine 27 acetylation (H3K27ac). Finally, we find that heterotypic clustering of CBP/P300-recruiting TFs is a strong predictor of total promoter H3K27ac. Our data support clustering of TF sites that broadly recruit KATs as a mechanism for widespread co-occurring histone acetylation marks. CoRec can be readily applied to different cell systems and provides a powerful approach to define TF-COF networks impacting chromatin state and gene regulation.
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Affiliation(s)
- Melissa M Inge
- Department of Biology, Boston University, Boston, MA 02215, USA
- Biological Design Center, Boston University, Boston, MA 02215, USA
| | - Rebekah Miller
- Department of Biology, Boston University, Boston, MA 02215, USA
- Biological Design Center, Boston University, Boston, MA 02215, USA
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Heather Hook
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - David Bray
- Department of Biology, Boston University, Boston, MA 02215, USA
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Jessica L Keenan
- Department of Biology, Boston University, Boston, MA 02215, USA
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Rose Zhao
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Trevor Siggers
- Department of Biology, Boston University, Boston, MA 02215, USA
- Biological Design Center, Boston University, Boston, MA 02215, USA
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
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2
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Nordin A, Pagella P, Zambanini G, Cantù C. Exhaustive identification of genome-wide binding events of transcriptional regulators. Nucleic Acids Res 2024; 52:e40. [PMID: 38499482 PMCID: PMC11040144 DOI: 10.1093/nar/gkae180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 02/20/2024] [Accepted: 02/29/2024] [Indexed: 03/20/2024] Open
Abstract
Genome-wide binding assays aspire to map the complete binding pattern of gene regulators. Common practice relies on replication-duplicates or triplicates-and high stringency statistics to favor false negatives over false positives. Here we show that duplicates and triplicates of CUT&RUN are not sufficient to discover the entire activity of transcriptional regulators. We introduce ICEBERG (Increased Capture of Enrichment By Exhaustive Replicate aGgregation), a pipeline that harnesses large numbers of CUT&RUN replicates to discover the full set of binding events and chart the line between false positives and false negatives. We employed ICEBERG to map the full set of H3K4me3-marked regions, the targets of the co-factor β-catenin, and those of the transcription factor TBX3, in human colorectal cancer cells. The ICEBERG datasets allow benchmarking of individual replicates, comparing the performance of peak calling and replication approaches, and expose the arbitrary nature of strategies to identify reproducible peaks. Instead of a static view of genomic targets, ICEBERG establishes a spectrum of detection probabilities across the genome for a given factor, underlying the intrinsic dynamicity of its mechanism of action, and permitting to distinguish frequent from rare regulation events. Finally, ICEBERG discovered instances, undetectable with other approaches, that underlie novel mechanisms of colorectal cancer progression.
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Affiliation(s)
- Anna Nordin
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Pierfrancesco Pagella
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Gianluca Zambanini
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Claudio Cantù
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
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3
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Inge MM, Miller R, Hook H, Bray D, Keenan JL, Zhao R, Gilmore TD, Siggers T. Rapid profiling of transcription factor-cofactor interaction networks reveals principles of epigenetic regulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.05.588333. [PMID: 38617258 PMCID: PMC11014505 DOI: 10.1101/2024.04.05.588333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Transcription factor (TF)-cofactor (COF) interactions define dynamic, cell-specific networks that govern gene expression; however, these networks are understudied due to a lack of methods for high-throughput profiling of DNA-bound TF-COF complexes. Here we describe the Cofactor Recruitment (CoRec) method for rapid profiling of cell-specific TF-COF complexes. We define a lysine acetyltransferase (KAT)-TF network in resting and stimulated T cells. We find promiscuous recruitment of KATs for many TFs and that 35% of KAT-TF interactions are condition specific. KAT-TF interactions identify NF-κB as a primary regulator of acutely induced H3K27ac. Finally, we find that heterotypic clustering of CBP/P300-recruiting TFs is a strong predictor of total promoter H3K27ac. Our data supports clustering of TF sites that broadly recruit KATs as a mechanism for widespread co-occurring histone acetylation marks. CoRec can be readily applied to different cell systems and provides a powerful approach to define TF-COF networks impacting chromatin state and gene regulation.
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Affiliation(s)
- M M Inge
- Department of Biology, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- These authors contributed equally
| | - R Miller
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- These authors contributed equally
| | - H Hook
- Department of Biology, Boston University, Boston, MA, USA
| | - D Bray
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
| | - J L Keenan
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
| | - R Zhao
- Department of Biology, Boston University, Boston, MA, USA
| | - T D Gilmore
- Department of Biology, Boston University, Boston, MA, USA
| | - T Siggers
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
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4
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Blayney JW, Francis H, Rampasekova A, Camellato B, Mitchell L, Stolper R, Cornell L, Babbs C, Boeke JD, Higgs DR, Kassouf M. Super-enhancers include classical enhancers and facilitators to fully activate gene expression. Cell 2023; 186:5826-5839.e18. [PMID: 38101409 PMCID: PMC10858684 DOI: 10.1016/j.cell.2023.11.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 07/06/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023]
Abstract
Super-enhancers are compound regulatory elements that control expression of key cell identity genes. They recruit high levels of tissue-specific transcription factors and co-activators such as the Mediator complex and contact target gene promoters with high frequency. Most super-enhancers contain multiple constituent regulatory elements, but it is unclear whether these elements have distinct roles in activating target gene expression. Here, by rebuilding the endogenous multipartite α-globin super-enhancer, we show that it contains bioinformatically equivalent but functionally distinct element types: classical enhancers and facilitator elements. Facilitators have no intrinsic enhancer activity, yet in their absence, classical enhancers are unable to fully upregulate their target genes. Without facilitators, classical enhancers exhibit reduced Mediator recruitment, enhancer RNA transcription, and enhancer-promoter interactions. Facilitators are interchangeable but display functional hierarchy based on their position within a multipartite enhancer. Facilitators thus play an important role in potentiating the activity of classical enhancers and ensuring robust activation of target genes.
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Affiliation(s)
- Joseph W Blayney
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Helena Francis
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Alexandra Rampasekova
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Brendan Camellato
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Leslie Mitchell
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Rosa Stolper
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Lucy Cornell
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Christian Babbs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA; Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY 11201, USA.
| | - Douglas R Higgs
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK; Chinese Academy of Medical Sciences Oxford Institute, Oxford OX3 7BN, UK.
| | - Mira Kassouf
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
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5
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Saavedra Núñez G, González-Villanueva E, Ramos P. Floral Development on Vitis vinifera Is Associated with MADS-Box Transcription Factors through the Transcriptional Regulation of VviZIP3. PLANTS (BASEL, SWITZERLAND) 2023; 12:3322. [PMID: 37765487 PMCID: PMC10535425 DOI: 10.3390/plants12183322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/11/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023]
Abstract
Several grapevine (Vitis vinifera L.) cultivars show a tendency to develop parthenocarpic seedless grapes, affecting fruit yield and quality. This reproductive disorder originates in defective ovule fertilization due to a failure in pollen tube growth. Zinc (Zn) is a crucial trace element, playing a vital role in various physiological and metabolic processes. It is particularly essential for the healthy growth of flowers and fruits. Insufficient zinc has been suggested as a potential reason for issues in this development process. This microelement is taken up through a mechanism that involves transporters, including the ZRT-IRT-like protein (ZIP) gene family, associated with the influx of Zn into the cell. In grapevines, 20 genes for ZIP-type transporters have been described. In this study, we analyzed the expression pattern of VviZIP3 during flower development and employ transgenic methods to assess its transcriptional regulation. Furthermore, through computational examination of the promoter region, we identified two CArG boxes, recognized as responsive elements to MADS transcription factors. These factors play a key role in shaping various components of a flower, such as pollen. Our investigation of the VviZIP3 promoter confirms the functionality of these CArG boxes. Overall, our results suggest that the increased expression of VviZIP3 during flowering is likely under the influence of MADS transcription factors.
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Affiliation(s)
- Germán Saavedra Núñez
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3460787, Chile; (G.S.N.); (E.G.-V.)
| | | | - Patricio Ramos
- Instituto de Ciencias Biológicas, Universidad de Talca, Talca 3460787, Chile; (G.S.N.); (E.G.-V.)
- Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3480112, Chile
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6
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Uyehara CM, Apostolou E. 3D enhancer-promoter interactions and multi-connected hubs: Organizational principles and functional roles. Cell Rep 2023; 42:112068. [PMID: 37059094 PMCID: PMC10556201 DOI: 10.1016/j.celrep.2023.112068] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/25/2022] [Accepted: 01/20/2023] [Indexed: 04/16/2023] Open
Abstract
The spatiotemporal control of gene expression is dependent on the activity of cis-acting regulatory sequences, called enhancers, which regulate target genes over variable genomic distances and, often, by skipping intermediate promoters, suggesting mechanisms that control enhancer-promoter communication. Recent genomics and imaging technologies have revealed highly complex enhancer-promoter interaction networks, whereas advanced functional studies have started interrogating the forces behind the physical and functional communication among multiple enhancers and promoters. In this review, we first summarize our current understanding of the factors involved in enhancer-promoter communication, with a particular focus on recent papers that have revealed new layers of complexities to old questions. In the second part of the review, we focus on a subset of highly connected enhancer-promoter "hubs" and discuss their potential functions in signal integration and gene regulation, as well as the putative factors that might determine their dynamics and assembly.
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Affiliation(s)
- Christopher M Uyehara
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA
| | - Effie Apostolou
- Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10021, USA.
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7
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Zambanini G, Nordin A, Jonasson M, Pagella P, Cantù C. A new CUT&RUN low volume-urea (LoV-U) protocol optimized for transcriptional co-factors uncovers Wnt/β-catenin tissue-specific genomic targets. Development 2022; 149:dev201124. [PMID: 36355069 PMCID: PMC10112916 DOI: 10.1242/dev.201124] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/26/2022] [Indexed: 11/11/2022]
Abstract
Upon WNT/β-catenin pathway activation, stabilized β-catenin travels to the nucleus where it associates with the TCF/LEF transcription factors, constitutively bound to genomic Wnt-responsive elements (WREs), to activate target gene transcription. Discovering the binding profile of β-catenin is therefore required to unambiguously assign direct targets of WNT signaling. Cleavage under targets and release using nuclease (CUT&RUN) has emerged as prime technique for mapping the binding profile of DNA-interacting proteins. Here, we present a modified version of CUT&RUN, named LoV-U (low volume and urea), that enables the robust and reproducible generation of β-catenin binding profiles, uncovering direct WNT/β-catenin target genes in human cells, as well as in cells isolated from developing mouse tissues. CUT&RUN-LoV-U outperforms original CUT&RUN when targeting co-factors that do not bind the DNA, can profile all classes of chromatin regulators and is well suited for simultaneous processing of several samples. We believe that the application of our protocol will allow the detection of the complex system of tissue-specific WNT/β-catenin target genes, together with other non-DNA-binding transcriptional regulators that act downstream of ontogenetically fundamental signaling cascades.
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Affiliation(s)
- Gianluca Zambanini
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping SE-58183, Sweden
- Department of Biomedical and Clinical Sciences (BKV), Division of Molecular Medicine and Virology (MMV), Faculty of Medicine and Health Sciences, Linköping University, Linköping SE-58183, Sweden
| | - Anna Nordin
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping SE-58183, Sweden
- Department of Biomedical and Clinical Sciences (BKV), Division of Molecular Medicine and Virology (MMV), Faculty of Medicine and Health Sciences, Linköping University, Linköping SE-58183, Sweden
| | - Mattias Jonasson
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping SE-58183, Sweden
- Department of Biomedical and Clinical Sciences (BKV), Division of Molecular Medicine and Virology (MMV), Faculty of Medicine and Health Sciences, Linköping University, Linköping SE-58183, Sweden
| | - Pierfrancesco Pagella
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping SE-58183, Sweden
- Department of Biomedical and Clinical Sciences (BKV), Division of Molecular Medicine and Virology (MMV), Faculty of Medicine and Health Sciences, Linköping University, Linköping SE-58183, Sweden
| | - Claudio Cantù
- Wallenberg Centre for Molecular Medicine, Linköping University, Linköping SE-58183, Sweden
- Department of Biomedical and Clinical Sciences (BKV), Division of Molecular Medicine and Virology (MMV), Faculty of Medicine and Health Sciences, Linköping University, Linköping SE-58183, Sweden
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8
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Llimos G, Gardeux V, Koch U, Kribelbauer JF, Hafner A, Alpern D, Pezoldt J, Litovchenko M, Russeil J, Dainese R, Moia R, Mahmoud AM, Rossi D, Gaidano G, Plass C, Lutsik P, Gerhauser C, Waszak SM, Boettiger A, Radtke F, Deplancke B. A leukemia-protective germline variant mediates chromatin module formation via transcription factor nucleation. Nat Commun 2022; 13:2042. [PMID: 35440565 PMCID: PMC9018852 DOI: 10.1038/s41467-022-29625-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 03/24/2022] [Indexed: 12/13/2022] Open
Abstract
Non-coding variants coordinate transcription factor (TF) binding and chromatin mark enrichment changes over regions spanning >100 kb. These molecularly coordinated regions are named "variable chromatin modules" (VCMs), providing a conceptual framework of how regulatory variation might shape complex traits. To better understand the molecular mechanisms underlying VCM formation, here, we mechanistically dissect a VCM-modulating noncoding variant that is associated with reduced chronic lymphocytic leukemia (CLL) predisposition and disease progression. This common, germline variant constitutes a 5-bp indel that controls the activity of an AXIN2 gene-linked VCM by creating a MEF2 binding site, which, upon binding, activates a super-enhancer-like regulatory element. This triggers a large change in TF binding activity and chromatin state at an enhancer cluster spanning >150 kb, coinciding with subtle, long-range chromatin compaction and robust AXIN2 up-regulation. Our results support a model in which the indel acts as an AXIN2 VCM-activating TF nucleation event, which modulates CLL pathology.
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Affiliation(s)
- Gerard Llimos
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Vincent Gardeux
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Ute Koch
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Judith F Kribelbauer
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Antonina Hafner
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Daniel Alpern
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Joern Pezoldt
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Maria Litovchenko
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Cancer Research UK Lung Cancer Centre of Excellence, University College London (UCL) Cancer Institute, Cancer Genome Evolution Research Group, London, UK
| | - Julie Russeil
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Riccardo Dainese
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Riccardo Moia
- Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy
| | - Abdurraouf Mokhtar Mahmoud
- Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy
| | - Davide Rossi
- Oncology Institute of Southern Switzerland, Università della Svizzera italiana, Bellinzona, Switzerland
- Institute of Oncology Research, Università della Svizzera italiana, Bellinzona, Switzerland
| | - Gianluca Gaidano
- Division of Hematology, Department of Translational Medicine, University of Eastern Piedmont, Novara, Italy
| | - Christoph Plass
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Pavlo Lutsik
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Clarissa Gerhauser
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian M Waszak
- Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo and Oslo University Hospital, Oslo, Norway
- Department of Pediatric Research, Division of Paediatric and Adolescent Medicine, Rikshospitalet, Oslo University Hospital, Oslo, Norway
| | - Alistair Boettiger
- Department of Developmental Biology, Stanford University, Stanford, CA, USA
| | - Freddy Radtke
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bart Deplancke
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
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9
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Woo SJ, Choi HJ, Park YH, Rengaraj D, Kim JK, Han JY. Amplification of immunity by engineering chicken MDA5 combined with the C terminal domain (CTD) of RIG-I. Appl Microbiol Biotechnol 2022; 106:1599-1613. [PMID: 35129655 DOI: 10.1007/s00253-022-11806-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 12/24/2021] [Accepted: 01/26/2022] [Indexed: 11/24/2022]
Abstract
Innate immune system is triggered by pattern recognition receptors (PRRs) recognition. Retinoic acid-inducible gene 1 (RIG-I) is a major sensor that recognizes RNA ligands. However, chickens have no homologue of RIG-I; instead, they rely on melanoma differentiation-associated protein 5 (MDA5) to recognize RNA ligands, which renders chickens susceptible to infection by influenza A viruses (IAVs). Here, we engineered the cMDA5 viral RNA sensing domain (C-terminal domain, CTD) such that it functions similarly to human RIG-I (hRIG-I) by mutating histidine 925 into phenylalanine, a key residue for hRIG-I RNA binding loop function, or by swapping the CTD of cMDA5 with that of hRIG-I or duck RIG-I (dRIG-I). The engineered cMDA5 gene was expressed in cMDA5 knockout DF-1 cells, and interferon-beta (IFN-β) activity and expression of interferon-related genes were measured after transfection of cells with RNA ligands of hRIG-I or human MDA5 (hMDA5). We found that both mutant cMDA5 and engineered cMDA5 triggered significantly stronger interferon-mediated immune responses than wild-type cMDA5. Moreover, engineered cMDA5 reduced the IAV titer by 100-fold compared with that in control cells. Collectively, engineered cMDA5/RIG-I CTD significantly enhanced interferon-mediated immune responses, making them invaluable strategies for production of IAV-resistant chickens. KEY POINTS: • Mutant chicken MDA5 with critical residue of RIG-I (phenylalanine) enhanced immunity. • Engineered chicken MDA5 with CTD of RIG-I increased IFN-mediated immune responses. • Engineered chicken MDA5 reduced influenza A virus titers by up to 100-fold.
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Affiliation(s)
- Seung Je Woo
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Hee Jung Choi
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Young Hyun Park
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Deivendran Rengaraj
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea
| | - Jin-Kyoo Kim
- Department of Microbiology, Changwon National University, Changwon, South Korea
| | - Jae Yong Han
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
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10
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Liang N, Deme L, Kong Q, Sun L, Cao Y, Wu T, Huang X, Xu S, Yang G. Divergence of Tbx4 hindlimb enhancer HLEA underlies the hindlimb loss during cetacean evolution. Genomics 2022; 114:110292. [DOI: 10.1016/j.ygeno.2022.110292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/13/2022] [Accepted: 02/01/2022] [Indexed: 11/04/2022]
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11
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Kasprzyk ME, Sura W, Dzikiewicz-Krawczyk A. Enhancing B-Cell Malignancies-On Repurposing Enhancer Activity towards Cancer. Cancers (Basel) 2021; 13:3270. [PMID: 34210001 PMCID: PMC8269369 DOI: 10.3390/cancers13133270] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 01/19/2023] Open
Abstract
B-cell lymphomas and leukemias derive from B cells at various stages of maturation and are the 6th most common cancer-related cause of death. While the role of several oncogenes and tumor suppressors in the pathogenesis of B-cell neoplasms was established, recent research indicated the involvement of non-coding, regulatory sequences. Enhancers are DNA elements controlling gene expression in a cell type- and developmental stage-specific manner. They ensure proper differentiation and maturation of B cells, resulting in production of high affinity antibodies. However, the activity of enhancers can be redirected, setting B cells on the path towards cancer. In this review we discuss different mechanisms through which enhancers are exploited in malignant B cells, from the well-studied translocations juxtaposing oncogenes to immunoglobulin loci, through enhancer dysregulation by sequence variants and mutations, to enhancer hijacking by viruses. We also highlight the potential of therapeutic targeting of enhancers as a direction for future investigation.
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12
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Agelopoulos M, Foutadakis S, Thanos D. The Causes and Consequences of Spatial Organization of the Genome in Regulation of Gene Expression. Front Immunol 2021; 12:682397. [PMID: 34149720 PMCID: PMC8212036 DOI: 10.3389/fimmu.2021.682397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 05/18/2021] [Indexed: 01/05/2023] Open
Abstract
Regulation of gene expression in time, space and quantity is orchestrated by the functional interplay of cis-acting elements and trans-acting factors. Our current view postulates that transcription factors recognize enhancer DNA and read the transcriptional regulatory code by cooperative DNA binding to specific DNA motifs, thus instructing the recruitment of transcriptional regulatory complexes forming a plethora of higher-ordered multi-protein-DNA and protein-protein complexes. Here, we reviewed the formation of multi-dimensional chromatin assemblies implicated in gene expression with emphasis on the regulatory role of enhancer hubs as coordinators of stochastic gene expression. Enhancer hubs contain many interacting regulatory elements and represent a remarkably dynamic and heterogeneous network of multivalent interactions. A functional consequence of such complex interaction networks could be that individual enhancers function synergistically to ensure coordination, tight control and robustness in regulation of expression of spatially connected genes. In this review, we discuss fundamental paradigms of such inter- and intra- chromosomal associations both in the context of immune-related genes and beyond.
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Affiliation(s)
| | | | - Dimitris Thanos
- Biomedical Research Foundation, Academy of Athens, Athens, Greece
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13
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Matsubara K, Matsubara Y, Uchikura Y, Takagi K, Yano A, Sugiyama T. HMGA1 Is a Potential Driver of Preeclampsia Pathogenesis by Interference with Extravillous Trophoblasts Invasion. Biomolecules 2021; 11:biom11060822. [PMID: 34072941 PMCID: PMC8227282 DOI: 10.3390/biom11060822] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/18/2022] Open
Abstract
Preeclampsia (PE) is a serious disease that can be fatal for the mother and fetus. The two-stage theory has been proposed as its cause, with the first stage comprising poor placentation associated with the failure of fertilized egg implantation. Successful implantation and placentation require maternal immunotolerance of the fertilized egg as a semi-allograft and appropriate extravillous trophoblast (EVT) invasion of the decidua and myometrium. The disturbance of EVT invasion during implantation in PE results in impaired spiral artery remodeling. PE is thought to be caused by hypoxia during remodeling failure-derived poor placentation, which results in chronic inflammation. High-mobility group protein A (HMGA) is involved in the growth and invasion of cancer cells and likely in the growth and invasion of trophoblasts. Its mechanism of action is associated with immunotolerance. Thus, HMGA is thought to play a pivotal role in successful pregnancy, and its dysfunction may be related to the pathogenesis of PE. The evaluation of HMGA function and its changes in PE might confirm that it is a reliable biomarker of PE and provide prospects for PE treatment through the induction of EVT proliferation and invasion during the implantation.
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Affiliation(s)
- Keiichi Matsubara
- Department of Regional Pediatrics and Perinatology, Graduate School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan
- Correspondence:
| | - Yuko Matsubara
- Department of Obstetrics and Gynecology, School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan; (Y.M.); (Y.U.); (K.T.); (A.Y.); (T.S.)
| | - Yuka Uchikura
- Department of Obstetrics and Gynecology, School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan; (Y.M.); (Y.U.); (K.T.); (A.Y.); (T.S.)
| | - Katsuko Takagi
- Department of Obstetrics and Gynecology, School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan; (Y.M.); (Y.U.); (K.T.); (A.Y.); (T.S.)
| | - Akiko Yano
- Department of Obstetrics and Gynecology, School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan; (Y.M.); (Y.U.); (K.T.); (A.Y.); (T.S.)
| | - Takashi Sugiyama
- Department of Obstetrics and Gynecology, School of Medicine, Ehime University, Ehime, Toon-shi 791-0295, Shitsukawa, Japan; (Y.M.); (Y.U.); (K.T.); (A.Y.); (T.S.)
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14
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Panigrahi A, O'Malley BW. Mechanisms of enhancer action: the known and the unknown. Genome Biol 2021; 22:108. [PMID: 33858480 PMCID: PMC8051032 DOI: 10.1186/s13059-021-02322-1] [Citation(s) in RCA: 144] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/23/2021] [Indexed: 12/13/2022] Open
Abstract
Differential gene expression mechanisms ensure cellular differentiation and plasticity to shape ontogenetic and phylogenetic diversity of cell types. A key regulator of differential gene expression programs are the enhancers, the gene-distal cis-regulatory sequences that govern spatiotemporal and quantitative expression dynamics of target genes. Enhancers are widely believed to physically contact the target promoters to effect transcriptional activation. However, our understanding of the full complement of regulatory proteins and the definitive mechanics of enhancer action is incomplete. Here, we review recent findings to present some emerging concepts on enhancer action and also outline a set of outstanding questions.
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Affiliation(s)
- Anil Panigrahi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
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15
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Avsec Ž, Weilert M, Shrikumar A, Krueger S, Alexandari A, Dalal K, Fropf R, McAnany C, Gagneur J, Kundaje A, Zeitlinger J. Base-resolution models of transcription-factor binding reveal soft motif syntax. Nat Genet 2021; 53:354-366. [PMID: 33603233 PMCID: PMC8812996 DOI: 10.1038/s41588-021-00782-6] [Citation(s) in RCA: 262] [Impact Index Per Article: 87.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 01/07/2021] [Indexed: 01/30/2023]
Abstract
The arrangement (syntax) of transcription factor (TF) binding motifs is an important part of the cis-regulatory code, yet remains elusive. We introduce a deep learning model, BPNet, that uses DNA sequence to predict base-resolution chromatin immunoprecipitation (ChIP)-nexus binding profiles of pluripotency TFs. We develop interpretation tools to learn predictive motif representations and identify soft syntax rules for cooperative TF binding interactions. Strikingly, Nanog preferentially binds with helical periodicity, and TFs often cooperate in a directional manner, which we validate using clustered regularly interspaced short palindromic repeat (CRISPR)-induced point mutations. Our model represents a powerful general approach to uncover the motifs and syntax of cis-regulatory sequences in genomics data.
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Affiliation(s)
- Žiga Avsec
- Department of Informatics, Technical University of Munich, Garching, Germany,Graduate School of Quantitative Biosciences (QBM), Ludwig-Maximilians-Universität München, Munich, Germany,Currently at DeepMind, London, UK
| | - Melanie Weilert
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Avanti Shrikumar
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Sabrina Krueger
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Amr Alexandari
- Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Khyati Dalal
- Stowers Institute for Medical Research, Kansas City, MO, USA,The University of Kansas Medical Center, Kansas City, KS, USA
| | - Robin Fropf
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Charles McAnany
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | - Julien Gagneur
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Anshul Kundaje
- Department of Computer Science, Stanford University, Stanford, CA, USA,Department of Genetics, Stanford University, Stanford, CA, USA,correspondence: ,
| | - Julia Zeitlinger
- Stowers Institute for Medical Research, Kansas City, MO, USA,The University of Kansas Medical Center, Kansas City, KS, USA,correspondence: ,
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16
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Fultang N, Li X, Li T, Chen YH. Myeloid-Derived Suppressor Cell Differentiation in Cancer: Transcriptional Regulators and Enhanceosome-Mediated Mechanisms. Front Immunol 2021; 11:619253. [PMID: 33519825 PMCID: PMC7840597 DOI: 10.3389/fimmu.2020.619253] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/30/2020] [Indexed: 01/16/2023] Open
Abstract
Myeloid-derived Suppressor Cells (MDSCs) are a sub-population of leukocytes that are important for carcinogenesis and cancer immunotherapy. During carcinogenesis or severe infections, inflammatory mediators induce MDSCs via aberrant differentiation of myeloid precursors. Although several transcription factors, including C/EBPβ, STAT3, c-Rel, STAT5, and IRF8, have been reported to regulate MDSC differentiation, none of them are specifically expressed in MDSCs. How these lineage-non-specific transcription factors specify MDSC differentiation in a lineage-specific manner is unclear. The recent discovery of the c-Rel-C/EBPβ enhanceosome in MDSCs may help explain these context-dependent roles. In this review, we examine several transcriptional regulators of MDSC differentiation, and discuss the concept of non-modular regulation of MDSC signature gene expression by transcription factors such as c-Rel and C/EBPß.
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Affiliation(s)
- Norman Fultang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | | | | | - Youhai H. Chen
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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17
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Papathanasiou M, Tsiftsoglou SA, Polyzos AP, Papadopoulou D, Valakos D, Klagkou E, Karagianni P, Pliatska M, Talianidis I, Agelopoulos M, Thanos D. Identification of a dynamic gene regulatory network required for pluripotency factor-induced reprogramming of mouse fibroblasts and hepatocytes. EMBO J 2021; 40:e102236. [PMID: 33034061 PMCID: PMC7780151 DOI: 10.15252/embj.2019102236] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 08/27/2020] [Accepted: 09/07/2020] [Indexed: 01/04/2023] Open
Abstract
The generation of induced pluripotent stem cells (iPSCs) from somatic cells provides an excellent model to study mechanisms of transcription factor-induced global alterations of the epigenome and genome function. Here, we have investigated the early transcriptional events of cellular reprogramming triggered by the co-expression of Oct4, Sox2, Klf4, and c-Myc (OSKM) in mouse embryonic fibroblasts (MEFs) and mouse hepatocytes (mHeps). In this analysis, we identified a gene regulatory network composed of nine transcriptional regulators (9TR; Cbfa2t3, Gli2, Irf6, Nanog, Ovol1, Rcan1, Taf1c, Tead4, and Tfap4), which are directly targeted by OSKM, in vivo. Functional studies using single and double shRNA knockdowns of any of these factors caused disruption of the network and dramatic reductions in reprogramming efficiency, indicating that this network is essential for the induction and establishment of pluripotency. We demonstrate that the stochastic co-expression of 9TR network components occurs in a remarkably small number of cells, approximating the percentage of terminally reprogrammed cells as a result of dynamic molecular events. Thus, the early DNA-binding patterns of OSKM and the subsequent probabilistic co-expression of essential 9TR components in subpopulations of cells undergoing reprogramming steer the reconstruction of a gene regulatory network marking the transition to pluripotency.
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Affiliation(s)
| | | | | | | | | | | | | | - Maria Pliatska
- Biomedical Research Foundation Academy of AthensAthensGreece
| | | | | | - Dimitris Thanos
- Biomedical Research Foundation Academy of AthensAthensGreece
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18
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Söderholm S, Cantù C. The WNT/β‐catenin dependent transcription: A tissue‐specific business. WIREs Mech Dis 2020; 13:e1511. [PMID: 33085215 PMCID: PMC9285942 DOI: 10.1002/wsbm.1511] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/11/2022]
Abstract
β‐catenin‐mediated Wnt signaling is an ancient cell‐communication pathway in which β‐catenin drives the expression of certain genes as a consequence of the trigger given by extracellular WNT molecules. The events occurring from signal to transcription are evolutionarily conserved, and their final output orchestrates countless processes during embryonic development and tissue homeostasis. Importantly, a dysfunctional Wnt/β‐catenin pathway causes developmental malformations, and its aberrant activation is the root of several types of cancer. A rich literature describes the multitude of nuclear players that cooperate with β‐catenin to generate a transcriptional program. However, a unified theory of how β‐catenin drives target gene expression is still missing. We will discuss two types of β‐catenin interactors: transcription factors that allow β‐catenin to localize at target regions on the DNA, and transcriptional co‐factors that ultimately activate gene expression. In contrast to the presumed universality of β‐catenin's action, the ensemble of available evidence suggests a view in which β‐catenin drives a complex system of responses in different cells and tissues. A malleable armamentarium of players might interact with β‐catenin in order to activate the right “canonical” targets in each tissue, developmental stage, or disease context. Discovering the mechanism by which each tissue‐specific β‐catenin response is executed will be crucial to comprehend how a seemingly universal pathway fosters a wide spectrum of processes during development and homeostasis. Perhaps more importantly, this could ultimately inform us about which are the tumor‐specific components that need to be targeted to dampen the activity of oncogenic β‐catenin. This article is categorized under:Cancer > Molecular and Cellular Physiology Cancer > Genetics/Genomics/Epigenetics Cancer > Stem Cells and Development
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Affiliation(s)
- Simon Söderholm
- Wallenberg Centre for Molecular Medicine Linköping University Linköping Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Health Science Linköping University Linköping Sweden
| | - Claudio Cantù
- Wallenberg Centre for Molecular Medicine Linköping University Linköping Sweden
- Department of Biomedical and Clinical Sciences, Division of Molecular Medicine and Virology, Faculty of Health Science Linköping University Linköping Sweden
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19
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Chen R, Zhang M, Zhou Y, Guo W, Yi M, Zhang Z, Ding Y, Wang Y. The application of histone deacetylases inhibitors in glioblastoma. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2020; 39:138. [PMID: 32682428 PMCID: PMC7368699 DOI: 10.1186/s13046-020-01643-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/13/2020] [Indexed: 12/14/2022]
Abstract
The epigenetic abnormality is generally accepted as the key to cancer initiation. Epigenetics that ensure the somatic inheritance of differentiated state is defined as a crucial factor influencing malignant phenotype without altering genotype. Histone modification is one such alteration playing an essential role in tumor formation, progression, and resistance to treatment. Notably, changes in histone acetylation have been strongly linked to gene expression, cell cycle, and carcinogenesis. The balance of two types of enzyme, histone acetyltransferases (HATs) and histone deacetylases (HDACs), determines the stage of histone acetylation and then the architecture of chromatin. Changes in chromatin structure result in transcriptional dysregulation of genes that are involved in cell-cycle progression, differentiation, apoptosis, and so on. Recently, HDAC inhibitors (HDACis) are identified as novel agents to keep this balance, leading to numerous researches on it for more effective strategies against cancers, including glioblastoma (GBM). This review elaborated influences on gene expression and tumorigenesis by acetylation and the antitumor mechanism of HDACis. Besdes, we outlined the preclinical and clinical advancement of HDACis in GBM as monotherapies and combination therapies.
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Affiliation(s)
- Rui Chen
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Mengxian Zhang
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Yangmei Zhou
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Wenjing Guo
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ming Yi
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ziyan Zhang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510000, Guangdong, China
| | - Yanpeng Ding
- Department of Oncology, Zhongnan Hospital, Wuhan University, Wuhan, 430030, China
| | - Yali Wang
- Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
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20
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Schwanke H, Stempel M, Brinkmann MM. Of Keeping and Tipping the Balance: Host Regulation and Viral Modulation of IRF3-Dependent IFNB1 Expression. Viruses 2020; 12:E733. [PMID: 32645843 PMCID: PMC7411613 DOI: 10.3390/v12070733] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 07/03/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
The type I interferon (IFN) response is a principal component of our immune system that allows to counter a viral attack immediately upon viral entry into host cells. Upon engagement of aberrantly localised nucleic acids, germline-encoded pattern recognition receptors convey their find via a signalling cascade to prompt kinase-mediated activation of a specific set of five transcription factors. Within the nucleus, the coordinated interaction of these dimeric transcription factors with coactivators and the basal RNA transcription machinery is required to access the gene encoding the type I IFN IFNβ (IFNB1). Virus-induced release of IFNβ then induces the antiviral state of the system and mediates further mechanisms for defence. Due to its key role during the induction of the initial IFN response, the activity of the transcription factor interferon regulatory factor 3 (IRF3) is tightly regulated by the host and fiercely targeted by viral proteins at all conceivable levels. In this review, we will revisit the steps enabling the trans-activating potential of IRF3 after its activation and the subsequent assembly of the multi-protein complex at the IFNβ enhancer that controls gene expression. Further, we will inspect the regulatory mechanisms of these steps imposed by the host cell and present the manifold strategies viruses have evolved to intervene with IFNβ transcription downstream of IRF3 activation in order to secure establishment of a productive infection.
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Affiliation(s)
- Hella Schwanke
- Institute of Genetics, Technische Universität Braunschweig, 38106 Braunschweig, Germany; (H.S.); (M.S.)
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Markus Stempel
- Institute of Genetics, Technische Universität Braunschweig, 38106 Braunschweig, Germany; (H.S.); (M.S.)
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Melanie M. Brinkmann
- Institute of Genetics, Technische Universität Braunschweig, 38106 Braunschweig, Germany; (H.S.); (M.S.)
- Viral Immune Modulation Research Group, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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21
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Li T, Li X, Zamani A, Wang W, Lee CN, Li M, Luo G, Eiler E, Sun H, Ghosh S, Jin J, Murali R, Ruan Q, Shi W, Chen YH. c-Rel Is a Myeloid Checkpoint for Cancer Immunotherapy. ACTA ACUST UNITED AC 2020; 1:507-517. [PMID: 33458695 DOI: 10.1038/s43018-020-0061-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Immunotherapy that targets lymphoid cell checkpoints holds great promise for curing cancer. However, a majority of cancer patients do not respond to this form of therapy. In addition to lymphoid cells, myeloid cells play essential roles in controlling immunity to cancer. Whether myeloid checkpoints exist that can be targeted to treat cancer is not well established. Here we show that c-Rel, a member of the nuclear factor (NF)-B family, specified the generation of myeloid-derived suppressor cells (MDSCs) by selectively turning on pro-tumoral genes while switching off anti-tumoral genes through a c-Rel enhanceosome. c-Rel deficiency in myeloid cells markedly inhibited cancer growth in mice, and pharmaceutical inhibition of c-Rel had the same effect. Combination therapy that blocked both c-Rel and the lymphoid checkpoint protein PD1 was more effective in treating cancer than blocking either alone. Thus, c-Rel is a myeloid checkpoint that can be targeted for treating cancer.
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Affiliation(s)
- Ting Li
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Contributed equally to this work
| | - Xinyuan Li
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.,Contributed equally to this work
| | - Ali Zamani
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wei Wang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Chin-Nien Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mingyue Li
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - George Luo
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Emily Eiler
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Honghong Sun
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sankar Ghosh
- Department of Microbiology and Immunology, College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences and Oncological Sciences, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ramachandran Murali
- Department of Biomedical Sciences, Research Division of Immunology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Qingguo Ruan
- Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Weiyun Shi
- Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Youhai H Chen
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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22
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Sheu K, Luecke S, Hoffmann A. Stimulus-specificity in the Responses of Immune Sentinel Cells. ACTA ACUST UNITED AC 2019; 18:53-61. [PMID: 32864512 DOI: 10.1016/j.coisb.2019.10.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Innate immune sentinel cells must initiate and orchestrate appropriate immune responses for myriad pathogens. These stimulus-specific gene expression responses are mediated by combinatorial and temporal coding within a handful of immune response signaling pathways. We outline the scope of our current understanding and indicate pressing outstanding questions. The innate immune response is a first-line defense against invading pathogens and coordinates the activation and recruitment of specialized immune cells, thereby initiating the adaptive immune response. While the adaptive immune system is capable of highly pathogen-specific immunity through the process of genetic recombination and clonal selection, innate immunity is frequently viewed as a catch-all system that initiates general immune activation. In this review, we are re-examining this view, as we are distinguishing between immune sentinel functions mediated by macrophages and dendritic cells and innate immune effector functions mediated by cells such as neutrophils, NK cells, etc. Given pathogen diversity, including modes of entry, replication cycles, and strategies of immune evasion and spread, all successive waves of the immune response ought to be tailored to the specific immune threat, leading us to postulate that immune sentinel functions by macrophages and dendritic cells ought to be highly stimulus-specific. Here we review the experimental evidence for stimulus-specific responses by immune sentinel cells which initiate and coordinate immune responses, as well as the mechanisms by which this specificity may be achieved.
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Affiliation(s)
- Katherine Sheu
- Institute for Quantitative and Computational Biosciences and Department for Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Stefanie Luecke
- Institute for Quantitative and Computational Biosciences and Department for Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| | - Alexander Hoffmann
- Institute for Quantitative and Computational Biosciences and Department for Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095
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23
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Li S, Kvon EZ, Visel A, Pennacchio LA, Ovcharenko I. Stable enhancers are active in development, and fragile enhancers are associated with evolutionary adaptation. Genome Biol 2019; 20:140. [PMID: 31307522 PMCID: PMC6631995 DOI: 10.1186/s13059-019-1750-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 06/28/2019] [Indexed: 12/13/2022] Open
Abstract
Background Despite continual progress in the identification and characterization of trait- and disease-associated variants that disrupt transcription factor (TF)-DNA binding, little is known about the distribution of TF binding deactivating mutations (deMs) in enhancer sequences. Here, we focus on elucidating the mechanism underlying the different densities of deMs in human enhancers. Results We identify two classes of enhancers based on the density of nucleotides prone to deMs. Firstly, fragile enhancers with abundant deM nucleotides are associated with the immune system and regular cellular maintenance. Secondly, stable enhancers with only a few deM nucleotides are associated with the development and regulation of TFs and are evolutionarily conserved. These two classes of enhancers feature different regulatory programs: the binding sites of pioneer TFs of FOX family are specifically enriched in stable enhancers, while tissue-specific TFs are enriched in fragile enhancers. Moreover, stable enhancers are more tolerant of deMs due to their dominant employment of homotypic TF binding site (TFBS) clusters, as opposed to the larger-extent usage of heterotypic TFBS clusters in fragile enhancers. Notably, the sequence environment and chromatin context of the cognate motif, other than the motif itself, contribute more to the susceptibility to deMs of TF binding. Conclusions This dichotomy of enhancer activity is conserved across different tissues, has a specific footprint in epigenetic profiles, and argues for a bimodal evolution of gene regulatory programs in vertebrates. Specifically encoded stable enhancers are evolutionarily conserved and associated with development, while differently encoded fragile enhancers are associated with the adaptation of species. Electronic supplementary material The online version of this article (10.1186/s13059-019-1750-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shan Li
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Evgeny Z Kvon
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Axel Visel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,United States Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA.,School of Natural Sciences, University of California, Merced, CA, 95343, USA
| | - Len A Pennacchio
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.,United States Department of Energy Joint Genome Institute, Walnut Creek, CA, 94598, USA.,Comparative Biochemistry Program, University of California, Berkeley, CA, 94720, USA
| | - Ivan Ovcharenko
- Computational Biology Branch, National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, 20892, USA.
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24
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Mookerjee-Basu J, Hua X, Ge L, Nicolas E, Li Q, Czyzewicz P, Zhongping D, Peri S, FuxmanBass JI, Walhout AJM, Kappes DJ. Functional Conservation of a Developmental Switch in Mammals since the Jurassic Age. Mol Biol Evol 2019; 36:39-53. [PMID: 30295892 DOI: 10.1093/molbev/msy191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
ThPOK is a "master regulator" of T lymphocyte lineage choice, whose presence or absence is sufficient to dictate development to the CD4 or CD8 lineages, respectively. Induction of ThPOK is transcriptionally regulated, via a lineage-specific silencer element, SilThPOK. Here, we take advantage of the available genome sequence data as well as site-specific gene targeting technology, to evaluate the functional conservation of ThPOK regulation across mammalian evolution, and assess the importance of motif grammar (order and orientation of TF binding sites) on SilThPOK function in vivo. We make three important points: First, the SilThPOK is present in marsupial and placental mammals, but is not found in available genome assemblies of nonmammalian vertebrates, indicating that it arose after divergence of mammals from other vertebrates. Secondly, by replacing the murine SilThPOK in situ with its marsupial equivalent using a knockin approach, we demonstrate that the marsupial SilThPOK supports correct CD4 T lymphocyte lineage-specification in mice. To our knowledge, this is the first in vivo demonstration of functional equivalency for a silencer element between marsupial and placental mammals using a definitive knockin approach. Finally, we show that alteration of the position/orientation of a highly conserved region within the murine SilThPOK is sufficient to destroy silencer activity in vivo, demonstrating that motif grammar of this "solid" synteny block is critical for silencer function. Dependence of SilThPOK function on motif grammar conserved since the mid-Jurassic age, 165 Ma, suggests that the SilThPOK operates as a silenceosome, by analogy with the previously proposed enhanceosome model.
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Affiliation(s)
- Jayati Mookerjee-Basu
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Xiang Hua
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Lu Ge
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Emmanuelle Nicolas
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Qin Li
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Philip Czyzewicz
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Dai Zhongping
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Suraj Peri
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
| | - Juan I FuxmanBass
- Program in Systems Biology, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Albertha J M Walhout
- Program in Systems Biology, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Dietmar J Kappes
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA
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25
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Vermunt MW, Zhang D, Blobel GA. The interdependence of gene-regulatory elements and the 3D genome. J Cell Biol 2019; 218:12-26. [PMID: 30442643 PMCID: PMC6314554 DOI: 10.1083/jcb.201809040] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/29/2018] [Accepted: 10/29/2018] [Indexed: 01/12/2023] Open
Abstract
Imaging studies, high-resolution chromatin conformation maps, and genome-wide occupancy data of architectural proteins have revealed that genome topology is tightly intertwined with gene expression. Cross-talk between gene-regulatory elements is often organized within insulated neighborhoods, and regulatory cues that induce transcriptional changes can reshape chromatin folding patterns and gene positioning within the nucleus. The cause-consequence relationship of genome architecture and gene expression is intricate, and its molecular mechanisms are under intense investigation. Here, we review the interdependency of transcription and genome organization with emphasis on enhancer-promoter contacts in gene regulation.
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Affiliation(s)
- Marit W Vermunt
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
| | - Di Zhang
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Gerd A Blobel
- Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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26
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Zandvakili A, Uhl JD, Campbell I, Salomone J, Song YC, Gebelein B. The cis-regulatory logic underlying abdominal Hox-mediated repression versus activation of regulatory elements in Drosophila. Dev Biol 2018; 445:226-236. [PMID: 30468713 DOI: 10.1016/j.ydbio.2018.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/12/2018] [Indexed: 11/19/2022]
Abstract
During development diverse transcription factor inputs are integrated by cis-regulatory modules (CRMs) to yield cell-specific gene expression. Defining how CRMs recruit the appropriate combinations of factors to either activate or repress gene expression remains a challenge. In this study, we compare and contrast the ability of two CRMs within the Drosophila embryo to recruit functional Hox transcription factor complexes. The DCRE CRM recruits Ultrabithorax (Ubx) and Abdominal-A (Abd-A) Hox complexes that include the Extradenticle (Exd) and Homothorax (Hth) transcription factors to repress the Distal-less leg selector gene, whereas the RhoA CRM selectively recruits Abd-A/Exd/Hth complexes to activate rhomboid and stimulate Epidermal Growth Factor secretion in sensory cell precursors. By swapping binding sites between these elements, we found that the RhoA Exd/Hth/Hox site configuration that mediates Abd-A specific activation can convey transcriptional repression by both Ubx and Abd-A when placed into the DCRE. We further show that the orientation and spacing of Hox sites relative to additional binding sites within the RhoA and DCRE is critical to mediate cell- and segment-specific output. These results indicate that the configuration of Exd, Hth, and Hox site within RhoA is neither Abd-A specific nor activation specific. Instead Hox specific output is largely dependent upon the presence of appropriately spaced and oriented binding sites for additional TF inputs. Taken together, these studies provide insight into the cis-regulatory logic used to generate cell-specific outputs via recruiting Hox transcription factor complexes.
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Affiliation(s)
- Arya Zandvakili
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA; Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Juli D Uhl
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA; Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Ian Campbell
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, USA
| | - Joseph Salomone
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA; Medical-Scientist Training Program, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Yuntao Charlie Song
- Graduate Program in Molecular and Developmental Biology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
| | - Brian Gebelein
- Division of Developmental Biology, Cincinnati Children's Hospital, 3333 Burnet Ave, MLC 7007, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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27
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Kuzin A, Smith S, Brody T, Odenwald WF. Structure and cis-regulatory analysis of a Drosophila grainyhead neuroblast enhancer. Genesis 2018; 56:e23094. [PMID: 29417712 DOI: 10.1002/dvg.23094] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 02/06/2023]
Abstract
Evolutionary analysis of cis-regulatory DNA reveals that enhancers consist of clusters of conserved sequence blocks (CSBs) that are made up of both unique and repeated sequence elements. This study seeks to address the basis for spatial and temporal regulation of neuroblas. A search for temporally restricted CNS NB enhancers identified one within the transcription factor grainyhead (grh) gene locus. The intronic enhancer, grh-15, contains two separable semi-autonomous activities, one that drives expression predominantly within the developing brain NBs and another in ventral cord NBs. To gain insight into the function of the CSBs constituting the brain-specific enhancer, we have systematically deleted each CSB and compared the activity of the altered enhancer to that of the full brain-specific enhancer. While our results indicate that information regulating enhancer activity is highly redundant, we have found that individual CSBs convey expression in subsets of larval lineages that are generated from either Type I or Type II NBs. These studies also highlight how evolutionary sequence conservation can be used as a guide the functional analysis of cis-regulatory DNA.
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Affiliation(s)
- Alexander Kuzin
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Svetlana Smith
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Thomas Brody
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
| | - Ward F Odenwald
- Neural Cell-Fate Determinants Section, NINDS, NIH, Bethesda, Maryland
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28
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Enane FO, Saunthararajah Y, Korc M. Differentiation therapy and the mechanisms that terminate cancer cell proliferation without harming normal cells. Cell Death Dis 2018; 9:912. [PMID: 30190481 PMCID: PMC6127320 DOI: 10.1038/s41419-018-0919-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 12/24/2022]
Abstract
Chemotherapeutic drugs have a common intent to activate apoptosis in tumor cells. However, master regulators of apoptosis (e.g., p53, p16/CDKN2A) are frequently genetically inactivated in cancers, resulting in multidrug resistance. An alternative, p53-independent method for terminating malignant proliferation is to engage terminal-differentiation. Normally, the exponential proliferation of lineage-committed progenitors, coordinated by the master transcription factor (TF) MYC, is self-limited by forward-differentiation to terminal lineage-fates. In cancers, however, this exponential proliferation is disengaged from terminal-differentiation. The mechanisms underlying this decoupling are mostly unknown. We performed a systematic review of published literature (January 2007-June 2018) to identify gene pathways linked to differentiation-failure in three treatment-recalcitrant cancers: hepatocellular carcinoma (HCC), ovarian cancer (OVC), and pancreatic ductal adenocarcinoma (PDAC). We analyzed key gene alterations in various apoptosis, proliferation and differentiation pathways to determine whether it is possible to predict treatment outcomes and suggest novel therapies. Poorly differentiated tumors were linked to poorer survival across histologies. Our analyses suggested loss-of-function events to master TF drivers of lineage-fates and their cofactors as being linked to differentiation-failure: genomic data in TCGA and ICGC databases demonstrated frequent haploinsufficiency of lineage master TFs (e.g., GATA4/6) in poorly differentiated tumors; the coactivators that these TFs use to activate genes (e.g. ARID1A, PBRM1) were also frequently inactivated by genetic mutation and/or deletion. By contrast, corepressor components (e.g., DNMT1, EED, UHRF1, and BAZ1A/B), that oppose coactivators to repress or turn off genes, were frequently amplified instead, and the level of amplification was highest in poorly differentiated lesions. This selection by neoplastic evolution towards unbalanced activity of transcriptional corepressors suggests these enzymes as candidate targets for inhibition aiming to re-engage forward-differentiation. This notion is supported by both pre-clinical and clinical trial literature.
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Affiliation(s)
- Francis O Enane
- Department of Medicine, Indiana University School of Medicine Indianapolis, Indianapolis, IN, 46202, USA.
| | - Yogen Saunthararajah
- Department of Hematology and Oncology, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, 44195, USA
- Department of Translational Hematology and Oncology Research, Taussig Cancer Center, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Murray Korc
- Department of Medicine, Indiana University School of Medicine Indianapolis, Indianapolis, IN, 46202, USA.
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- The Pancreatic Cancer Signature Center at Indiana University Purdue University Indianapolis and Indiana University Simon Cancer, Indianapolis, IN, 46202, USA.
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29
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Smith JA. Regulation of Cytokine Production by the Unfolded Protein Response; Implications for Infection and Autoimmunity. Front Immunol 2018; 9:422. [PMID: 29556237 PMCID: PMC5844972 DOI: 10.3389/fimmu.2018.00422] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/16/2018] [Indexed: 12/14/2022] Open
Abstract
Protein folding in the endoplasmic reticulum (ER) is an essential cell function. To safeguard this process in the face of environmental threats and internal stressors, cells mount an evolutionarily conserved response known as the unfolded protein response (UPR). Invading pathogens induce cellular stress that impacts protein folding, thus the UPR is well situated to sense danger and contribute to immune responses. Cytokines (inflammatory cytokines and interferons) critically mediate host defense against pathogens, but when aberrantly produced, may also drive pathologic inflammation. The UPR influences cytokine production on multiple levels, from stimulation of pattern recognition receptors, to modulation of inflammatory signaling pathways, and the regulation of cytokine transcription factors. This review will focus on the mechanisms underlying cytokine regulation by the UPR, and the repercussions of this relationship for infection and autoimmune/autoinflammatory diseases. Interrogation of viral and bacterial infections has revealed increasing numbers of examples where pathogens induce or modulate the UPR and implicated UPR-modulated cytokines in host response. The flip side of this coin, the UPR/ER stress responses have been increasingly recognized in a variety of autoimmune and inflammatory diseases. Examples include monogenic disorders of ER function, diseases linked to misfolding protein (HLA-B27 and spondyloarthritis), diseases directly implicating UPR and autophagy genes (inflammatory bowel disease), and autoimmune diseases targeting highly secretory cells (e.g., diabetes). Given the burgeoning interest in pharmacologically targeting the UPR, greater discernment is needed regarding how the UPR regulates cytokine production during specific infections and autoimmune processes, and the relative place of this interaction in pathogenesis.
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Affiliation(s)
- Judith A Smith
- Department of Pediatrics, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States.,Department of Medical Microbiology and Immunology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, United States
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30
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Shu G, Kramár EA, López AJ, Huynh G, Wood MA, Kwapis JL. Deleting HDAC3 rescues long-term memory impairments induced by disruption of the neuron-specific chromatin remodeling subunit BAF53b. ACTA ACUST UNITED AC 2018; 25:109-114. [PMID: 29449454 PMCID: PMC5817283 DOI: 10.1101/lm.046920.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/19/2017] [Indexed: 12/31/2022]
Abstract
Multiple epigenetic mechanisms, including histone acetylation and nucleosome remodeling, are known to be involved in long-term memory formation. Enhancing histone acetylation by deleting histone deacetylases, like HDAC3, typically enhances long-term memory formation. In contrast, disrupting nucleosome remodeling by blocking the neuron-specific chromatin remodeling subunit BAF53b impairs long-term memory. Here, we show that deleting HDAC3 can ameliorate the impairments in both long-term memory and synaptic plasticity caused by BAF53b mutation. This suggests a dynamic interplay exists between histone acetylation/deacetylation and nucleosome remodeling mechanisms in the regulation of memory formation.
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Affiliation(s)
- Guanhua Shu
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
| | - Enikö A Kramár
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
| | - Alberto J López
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
| | - Grace Huynh
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
| | - Marcelo A Wood
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
| | - Janine L Kwapis
- Department of Neurobiology and Behavior, University of California, Irvine, California, 92697, USA.,Center for Neurobiology of Learning and Memory, Irvine, California, 92697, USA
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31
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Conserved Upstream Regulatory Regions in Mammalian Tyrosine Hydroxylase. Mol Neurobiol 2018; 55:7340-7351. [PMID: 29404959 DOI: 10.1007/s12035-018-0936-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 01/25/2018] [Indexed: 10/18/2022]
Abstract
Tyrosine hydroxylase (Th) encodes the rate-limiting enzyme in catecholamine biosynthesis, and the regulation of its transcription is critical for the specification and maintenance of catecholaminergic neuron phenotypes. For many genes, regulatory genomic DNA sequences that are upstream of the proximal promoter control expression levels as well as region-specific expression patterns. The regulatory architecture of the genomic DNA upstream of the Th proximal promoter, however, is poorly understood. In this study, we examined the 11 kb upstream nucleotide sequence of Th from nine mammalian species and identified five highly conserved regions. Using cultured human cells and mouse olfactory bulb tissue, chromatin immunoprecipitation (ChIP) assays show that these conserved regions recruit transcription factors that are established regulators of Th transcription (such as NURR1, PITX3, FOXA2, MEIS2, and PAX6). This analysis also identified a conserved binding site for CTCF, and functional studies in cultured human cells and ChIP assays with mouse tissue show that CTCF is a novel regulator of Th transcription in the forebrain. Together, the findings in this study provide key insights into the upstream regulatory genomic architecture and regulatory mechanisms controlling mammalian Th gene transcription.
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32
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Hassan F, Ni S, Arnett TC, McKell MC, Kennedy MA. Adenovirus-Mediated Delivery of Decoy Hyper Binding Sites Targeting Oncogenic HMGA1 Reduces Pancreatic and Liver Cancer Cell Viability. MOLECULAR THERAPY-ONCOLYTICS 2018; 8:52-61. [PMID: 29511732 PMCID: PMC5832671 DOI: 10.1016/j.omto.2018.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 01/17/2018] [Indexed: 11/23/2022]
Abstract
High mobility group AT-hook 1 (HMGA1) protein is an oncogenic architectural transcription factor that plays an essential role in early development, but it is also implicated in many human cancers. Elevated levels of HMGA1 in cancer cells cause misregulation of gene expression and are associated with increased cancer cell proliferation and increased chemotherapy resistance. We have devised a strategy of using engineered viruses to deliver decoy hyper binding sites for HMGA1 to the nucleus of cancer cells with the goal of sequestering excess HMGA1 at the decoy hyper binding sites due to binding competition. Sequestration of excess HMGA1 at the decoy binding sites is intended to reduce HMGA1 binding at the naturally occurring genomic HMGA1 binding sites, which should result in normalized gene expression and restored sensitivity to chemotherapy. As proof of principle, we engineered the replication defective adenovirus serotype 5 genome to contain hyper binding sites for HMGA1 composed of six copies of an individual HMGA1 binding site, referred to as HMGA-6. A 70%–80% reduction in cell viability and increased sensitivity to gemcitabine was observed in five different pancreatic and liver cancer cell lines 72 hr after infection with replication defective engineered adenovirus serotype 5 virus containing the HMGA-6 decoy hyper binding sites. The decoy hyper binding site strategy should be general for targeting overexpression of any double-stranded DNA-binding oncogenic transcription factor responsible for cancer cell proliferation.
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Affiliation(s)
- Faizule Hassan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Shuisong Ni
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Tyler C Arnett
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Melanie C McKell
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Michael A Kennedy
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
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33
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Chiefari E, Foti DP, Sgarra R, Pegoraro S, Arcidiacono B, Brunetti FS, Greco M, Manfioletti G, Brunetti A. Transcriptional Regulation of Glucose Metabolism: The Emerging Role of the HMGA1 Chromatin Factor. Front Endocrinol (Lausanne) 2018; 9:357. [PMID: 30034366 PMCID: PMC6043803 DOI: 10.3389/fendo.2018.00357] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 06/13/2018] [Indexed: 02/06/2023] Open
Abstract
HMGA1 (high mobility group A1) is a nonhistone architectural chromosomal protein that functions mainly as a dynamic regulator of chromatin structure and gene transcription. As such, HMGA1 is involved in a variety of fundamental cellular processes, including gene expression, epigenetic regulation, cell differentiation and proliferation, as well as DNA repair. In the last years, many reports have demonstrated a role of HMGA1 in the transcriptional regulation of several genes implicated in glucose homeostasis. Initially, it was proved that HMGA1 is essential for normal expression of the insulin receptor (INSR), a critical link in insulin action and glucose homeostasis. Later, it was demonstrated that HMGA1 is also a downstream nuclear target of the INSR signaling pathway, representing a novel mediator of insulin action and function at this level. Moreover, other observations have indicated the role of HMGA1 as a positive modulator of the Forkhead box protein O1 (FoxO1), a master regulatory factor for gluconeogenesis and glycogenolysis, as well as a positive regulator of the expression of insulin and of a series of circulating proteins that are involved in glucose counterregulation, such as the insulin growth factor binding protein 1 (IGFBP1), and the retinol binding protein 4 (RBP4). Thus, several lines of evidence underscore the importance of HMGA1 in the regulation of glucose production and disposal. Consistently, lack of HMGA1 causes insulin resistance and diabetes in humans and mice, while variations in the HMGA1 gene are associated with the risk of type 2 diabetes and metabolic syndrome, two highly prevalent diseases that share insulin resistance as a common pathogenetic mechanism. This review intends to give an overview about our current knowledge on the role of HMGA1 in glucose metabolism. Although research in this field is ongoing, many aspects still remain elusive. Future directions to improve our insights into the pathophysiology of glucose homeostasis may include epigenetic studies and the use of "omics" strategies. We believe that a more comprehensive understanding of HMGA1 and its networks may reveal interesting molecular links between glucose metabolism and other biological processes, such as cell proliferation and differentiation.
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Affiliation(s)
- Eusebio Chiefari
- Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Daniela P. Foti
- Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Riccardo Sgarra
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Silvia Pegoraro
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Biagio Arcidiacono
- Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Francesco S. Brunetti
- Department of Medical and Surgical Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | - Manfredi Greco
- Department of Clinical and Experimental Medicine, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
| | | | - Antonio Brunetti
- Department of Health Sciences, University “Magna Græcia” of Catanzaro, Catanzaro, Italy
- *Correspondence: Antonio Brunetti
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34
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Brown AJ, Gibson SJ, Hatton D, James DC. In silico design of context-responsive mammalian promoters with user-defined functionality. Nucleic Acids Res 2017; 45:10906-10919. [PMID: 28977454 PMCID: PMC5737543 DOI: 10.1093/nar/gkx768] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 08/22/2017] [Indexed: 12/19/2022] Open
Abstract
Comprehensive de novo-design of complex mammalian promoters is restricted by unpredictable combinatorial interactions between constituent transcription factor regulatory elements (TFREs). In this study, we show that modular binding sites that do not function cooperatively can be identified by analyzing host cell transcription factor expression profiles, and subsequently testing cognate TFRE activities in varying homotypic and heterotypic promoter architectures. TFREs that displayed position-insensitive, additive function within a specific expression context could be rationally combined together in silico to create promoters with highly predictable activities. As TFRE order and spacing did not affect the performance of these TFRE-combinations, compositions could be specifically arranged to preclude the formation of undesirable sequence features. This facilitated simple in silico-design of promoters with context-required, user-defined functionalities. To demonstrate this, we de novo-created promoters for biopharmaceutical production in CHO cells that exhibited precisely designed activity dynamics and long-term expression-stability, without causing observable retroactive effects on cellular performance. The design process described can be utilized for applications requiring context-responsive, customizable promoter function, particularly where co-expression of synthetic TFs is not suitable. Although the synthetic promoter structure utilized does not closely resemble native mammalian architectures, our findings also provide additional support for a flexible billboard model of promoter regulation.
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Affiliation(s)
- Adam J Brown
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield S1 3JD, UK
| | - Suzanne J Gibson
- Biopharmaceutical Development, MedImmune, Cambridge CB21 6GH, UK
| | - Diane Hatton
- Biopharmaceutical Development, MedImmune, Cambridge CB21 6GH, UK
| | - David C James
- Department of Chemical and Biological Engineering, University of Sheffield, Mappin St., Sheffield S1 3JD, UK
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Peacock J, Jaynes JB. Using competition assays to quantitatively model cooperative binding by transcription factors and other ligands. Biochim Biophys Acta Gen Subj 2017; 1861:2789-2801. [PMID: 28774855 PMCID: PMC5623634 DOI: 10.1016/j.bbagen.2017.07.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/27/2017] [Accepted: 07/29/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND The affinities of DNA binding proteins for target sites can be used to model the regulation of gene expression. These proteins can bind to DNA cooperatively, strongly impacting their affinity and specificity. However, current methods for measuring cooperativity do not provide the means to accurately predict binding behavior over a wide range of concentrations. METHODS We use standard computational and mathematical methods, and develop novel methods as described in Results. RESULTS We explore some complexities of cooperative binding, and develop an improved method for relating in vitro measurements to in vivo function, based on ternary complex formation. We derive expressions for the equilibria among the various complexes, and explore the limitations of binding experiments that model the system using a single parameter. We describe how to use single-ligand binding and ternary complex formation in tandem to determine parameters that have thermodynamic relevance. We develop an improved method for finding both single-ligand dissociation constants and concentrations simultaneously. We show how the cooperativity factor can be found when only one of the single-ligand dissociation constants can be measured. CONCLUSIONS The methods that we develop constitute an optimized approach to accurately model cooperative binding. GENERAL SIGNIFICANCE The expressions and methods we develop for modeling and analyzing DNA binding and cooperativity are applicable to most cases where multiple ligands bind to distinct sites on a common substrate. The parameters determined using these methods can be fed into models of higher-order cooperativity to increase their predictive power.
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Affiliation(s)
- Jacob Peacock
- Dept. of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - James B Jaynes
- Dept. of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
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Ubhe S, Rawat M, Verma S, Anamika K, Karmodiya K. Genome-wide identification of novel intergenic enhancer-like elements: implications in the regulation of transcription in Plasmodium falciparum. BMC Genomics 2017; 18:656. [PMID: 28836940 PMCID: PMC5569477 DOI: 10.1186/s12864-017-4052-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 08/11/2017] [Indexed: 01/28/2023] Open
Abstract
Background The molecular mechanisms of transcriptional regulation are poorly understood in Plasmodium falciparum. In addition, most of the genes in Plasmodium falciparum are transcriptionally poised and only a handful of cis-regulatory elements are known to operate in transcriptional regulation. Here, we employed an epigenetic signature based approach to identify significance of previously uncharacterised intergenic regions enriched with histone modification marks leading to discovery of enhancer-like elements. Results We found that enhancer-like elements are significantly enriched with H3K4me1, generate unique non-coding bi-directional RNAs and majority of them can function as cis-regulators. Furthermore, functional enhancer reporter assay demonstrates that the enhancer-like elements regulate transcription of target genes in Plasmodium falciparum. Our study also suggests that the Plasmodium genome segregates functionally related genes into discrete housekeeping and pathogenicity/virulence clusters, presumably for robust transcriptional control of virulence/pathogenicity genes. Conclusions This report contributes to the understanding of parasite regulatory genomics by identification of enhancer-like elements, defining their epigenetic and transcriptional features and provides a resource of functional cis-regulatory elements that may give insights into the virulence/pathogenicity of Plasmodium falciparum. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-4052-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Suyog Ubhe
- Department of Biology, Indian Institute of Science Education and Research, Pashan, Pune, 411008, India
| | - Mukul Rawat
- Department of Biology, Indian Institute of Science Education and Research, Pashan, Pune, 411008, India
| | - Srikant Verma
- Labs, Persistent Systems Limited, Pingala - Aryabhata, Erandwane, Pune, 411004, India
| | - Krishanpal Anamika
- Labs, Persistent Systems Limited, Pingala - Aryabhata, Erandwane, Pune, 411004, India
| | - Krishanpal Karmodiya
- Department of Biology, Indian Institute of Science Education and Research, Pashan, Pune, 411008, India.
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Singh P, Han EH, Endrizzi JA, O'Brien RM, Chi YI. Crystal structures reveal a new and novel FoxO1 binding site within the human glucose-6-phosphatase catalytic subunit 1 gene promoter. J Struct Biol 2017; 198:54-64. [PMID: 28223045 DOI: 10.1016/j.jsb.2017.02.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/10/2017] [Accepted: 02/14/2017] [Indexed: 01/07/2023]
Abstract
Human glucose-6-phosphatase plays a vital role in blood glucose homeostasis and holds promise as a therapeutic target for diabetes. Expression of its catalytic subunit gene 1 (G6PC1) is tightly regulated by metabolic-response transcription factors such as FoxO1 and CREB. Although at least three potential FoxO1 binding sites (insulin response elements, IREs) and one CREB binding site (cAMP response element, CRE) within the proximal region of the G6PC1 promoter have been identified, the interplay between FoxO1 and CREB and between FoxO1 bound at multiple IREs has not been well characterized. Here we present the crystal structures of the FoxO1 DNA binding domain in complex with the G6PC1 promoter. These complexes reveal the presence of a new non-consensus FoxO1 binding site that overlaps the CRE, suggesting a mutual exclusion mechanism for FoxO1 and CREB binding at the G6PC1 promoter. Additional findings include (i) non-canonical FoxO1 recognition sites, (ii) incomplete FoxO1 occupancies at the available IRE sites, and (iii) FoxO1 dimeric interactions that may play a role in stabilizing DNA looping. These findings provide insight into the regulation of G6PC1 gene transcription by FoxO1, and demonstrate a high versatility of target gene recognition by FoxO1 that correlates with its diverse roles in biology.
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Affiliation(s)
- Puja Singh
- Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912, United States
| | - Eun Hee Han
- Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912, United States
| | - James A Endrizzi
- Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912, United States
| | - Richard M O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, United States.
| | - Young-In Chi
- Section of Structural Biology, Hormel Institute, University of Minnesota, Austin, MN 55912, United States.
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Buffry AD, Mendes CC, McGregor AP. The Functionality and Evolution of Eukaryotic Transcriptional Enhancers. ADVANCES IN GENETICS 2016; 96:143-206. [PMID: 27968730 DOI: 10.1016/bs.adgen.2016.08.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Enhancers regulate precise spatial and temporal patterns of gene expression in eukaryotes and, moreover, evolutionary changes in these modular cis-regulatory elements may represent the predominant genetic basis for phenotypic evolution. Here, we review approaches to identify and functionally analyze enhancers and their transcription factor binding sites, including assay for transposable-accessible chromatin-sequencing (ATAC-Seq) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9, respectively. We also explore enhancer functionality, including how transcription factor binding sites combine to regulate transcription, as well as research on shadow and super enhancers, and how enhancers can act over great distances and even in trans. Finally, we discuss recent theoretical and empirical data on how transcription factor binding sites and enhancers evolve. This includes how the function of enhancers is maintained despite the turnover of transcription factor binding sites as well as reviewing studies where mutations in enhancers have been shown to underlie morphological change.
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Affiliation(s)
- A D Buffry
- Oxford Brookes University, Oxford, United Kingdom
| | - C C Mendes
- Oxford Brookes University, Oxford, United Kingdom
| | - A P McGregor
- Oxford Brookes University, Oxford, United Kingdom
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Enhancer decommissioning by Snail1-induced competitive displacement of TCF7L2 and down-regulation of transcriptional activators results in EPHB2 silencing. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1353-1367. [PMID: 27504909 DOI: 10.1016/j.bbagrm.2016.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/25/2016] [Accepted: 08/04/2016] [Indexed: 12/20/2022]
Abstract
Transcriptional silencing is a major cause for the inactivation of tumor suppressor genes, however, the underlying mechanisms are only poorly understood. The EPHB2 gene encodes a receptor tyrosine kinase that controls epithelial cell migration and allocation in intestinal crypts. Through its ability to restrict cell spreading, EPHB2 functions as a tumor suppressor in colorectal cancer whose expression is frequently lost as tumors progress to the carcinoma stage. Previously we reported that EPHB2 expression depends on a transcriptional enhancer whose activity is diminished in EPHB2 non-expressing cells. Here we investigated the mechanisms that lead to EPHB2 enhancer inactivation. We show that expression of EPHB2 and SNAIL1 - an inducer of epithelial-mesenchymal transition (EMT) - is anti-correlated in colorectal cancer cell lines and tumors. In a cellular model of Snail1-induced EMT, we observe that features of active chromatin at the EPHB2 enhancer are diminished upon expression of murine Snail1. We identify the transcription factors FOXA1, MYB, CDX2 and TCF7L2 as EPHB2 enhancer factors and demonstrate that Snail1 indirectly inactivates the EPHB2 enhancer by downregulation of FOXA1 and MYB. In addition, Snail1 induces the expression of Lymphoid enhancer factor 1 (LEF1) which competitively displaces TCF7L2 from the EPHB2 enhancer. In contrast to TCF7L2, however, LEF1 appears to repress the EPHB2 enhancer. Our findings underscore the importance of transcriptional enhancers for gene regulation under physiological and pathological conditions and show that SNAIL1 employs a combinatorial mechanism to inactivate the EPHB2 enhancer based on activator deprivation and competitive displacement of transcription factors.
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Bose S, Ganguly S, Kumar S, Boockfor FR. A Pit-1 Binding Site Adjacent to E-box133 in the Rat PRL Promoter is Necessary for Pulsatile Gene Expression Activity. Neurochem Res 2016; 41:1390-400. [PMID: 26875730 DOI: 10.1007/s11064-016-1843-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 12/16/2015] [Accepted: 01/22/2016] [Indexed: 02/03/2023]
Abstract
Recent evidence reveals that prolactin gene expression (PRL-GE) in mammotropes occurs in pulses, but the molecular process(es) underlying this phenomenon remains unclear. Earlier, we have identified an E-box (E-box133) in the rat PRL promoter that binds several circadian elements and is critical for this dynamic process. Preliminary analysis revealed a Pit-1 binding site (P2) located immediately adjacent to this E-box133 raising the possibility that some type of functional relationship may exist between these two promoter regions. In this study, using serum shocked GH3 cell culture system to synchronize PRL-GE activity, we determined that Pit-1 gene expression occurred in pulses with time phases similar to that for PRL. Interestingly, EMSA analysis not only confirmed Pit-1 binding to the P2 site, but also revealed an interaction with factor(s) binding to the adjacent E-box133 promoter element. Additionally, down-regulation of Pit-1 by siRNA reduced PRL levels during pulse periods. Thus, using multiple evidences, our results demonstrate clearly that the Pit-1 P2 site is necessary for PRL-GE elaboration. Furthermore, the proximity of this critical Pit-1 binding site (P2) and the E-box133 element coupled with the evidences of a site-to-site protein interactions suggest that the process of PRL-GE pulse activity might involve more dynamic and intricate cross-talks between promoter elements that may span some, or all, of the proximal region of the PRL promoter in driving its pulsatile expression.
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Affiliation(s)
- Sudeep Bose
- Amity Institute of Biotechnology, Amity University, Gautam Buddha Nagar, Sector-125, Noida, UP, 201313, India. .,Laboratory of Molecular Dynamics, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, 29425, USA.
| | - Surajit Ganguly
- Institute of Molecular Medicine, 254 Okhla Industrial Estate, Phase III, New Delhi, 110020, India
| | - Sachin Kumar
- Amity Institute of Biotechnology, Amity University, Gautam Buddha Nagar, Sector-125, Noida, UP, 201313, India
| | - Fredric R Boockfor
- Laboratory of Molecular Dynamics, Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, 29425, USA
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Lück S, Westermark PO. Circadian mRNA expression: insights from modeling and transcriptomics. Cell Mol Life Sci 2016; 73:497-521. [PMID: 26496725 PMCID: PMC11108398 DOI: 10.1007/s00018-015-2072-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/13/2015] [Accepted: 10/14/2015] [Indexed: 01/08/2023]
Abstract
Circadian clocks synchronize organisms to the 24 h rhythms of the environment. These clocks persist under constant conditions, have their origin at the cellular level, and produce an output of rhythmic mRNA expression affecting thousands of transcripts in many mammalian cell types. Here, we review the charting of circadian output rhythms in mRNA expression, focusing on mammals. We emphasize the challenges in statistics, interpretation, and quantitative descriptions that such investigations have faced and continue to face, and outline remaining outstanding questions.
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Affiliation(s)
- Sarah Lück
- Institute for Theoretical Biology, Charité - Universitätsmedizin Berlin, Invalidenstrasse 43, 10115, Berlin, Germany
| | - Pål O Westermark
- Institute for Theoretical Biology, Charité - Universitätsmedizin Berlin, Invalidenstrasse 43, 10115, Berlin, Germany.
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Crocker J, Noon EPB, Stern DL. The Soft Touch: Low-Affinity Transcription Factor Binding Sites in Development and Evolution. Curr Top Dev Biol 2016; 117:455-69. [PMID: 26969995 DOI: 10.1016/bs.ctdb.2015.11.018] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Transcription factor proteins regulate gene expression by binding to specific DNA regions. Most studies of transcription factor binding sites have focused on the highest affinity sites for each factor. There is abundant evidence, however, that binding sites with a range of affinities, including very low affinities, are critical to gene regulation. Here, we present the theoretical and experimental evidence for the importance of low-affinity sites in gene regulation and development. We also discuss the implications of the widespread use of low-affinity sites in eukaryotic genomes for robustness, precision, specificity, and evolution of gene regulation.
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Affiliation(s)
- Justin Crocker
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - Ella Preger-Ben Noon
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA
| | - David L Stern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, USA.
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Abstract
Interferon regulatory factor 5 (IRF5) has been demonstrated as a key transcription factor of the immune system, playing important roles in modulating inflammatory immune responses in numerous cell types including dendritic cells, macrophages, and B cells. As well as driving the expression of type I interferon in antiviral responses, IRF5 is also crucial for driving macrophages toward a proinflammatory phenotype by regulating cytokine and chemokine expression and modulating B-cell maturity and antibody production. This review highlights the functional importance of IRF5 in a disease setting, by discussing polymorphic mutations at the human Irf5 locus that lead to susceptibility to systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease. In concordance with this, we also discuss lessons in IRF5 functionality learned from murine in vivo models of autoimmune disease and inflammation and hypothesize that modulation of IRF5 activity and expression could provide potential therapeutic benefits in the clinic.
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Affiliation(s)
- Hayley L Eames
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
| | - Alastair L Corbin
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
| | - Irina A Udalova
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom.
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Functional interplay between histone H1 and HMG proteins in chromatin. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1859:462-7. [PMID: 26455954 DOI: 10.1016/j.bbagrm.2015.10.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 11/22/2022]
Abstract
The dynamic interaction of nucleosome binding proteins with their chromatin targets is an important element in regulating the structure and function of chromatin. Histone H1 variants and High Mobility Group (HMG) proteins are ubiquitously expressed in all vertebrate cells, bind dynamically to chromatin, and are known to affect chromatin condensation and the ability of regulatory factors to access their genomic binding sites. Here, we review the studies that focus on the interactions between H1 and HMGs and highlight the functional consequences of the interplay between these architectural chromatin binding proteins. H1 and HMG proteins are mobile molecules that bind to nucleosomes as members of a dynamic protein network. All HMGs compete with H1 for chromatin binding sites, in a dose dependent fashion, but each HMG family has specific effects on the interaction of H1 with chromatin. The interplay between H1 and HMGs affects chromatin organization and plays a role in epigenetic regulation.
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Fagoe ND, Attwell CL, Kouwenhoven D, Verhaagen J, Mason MRJ. Overexpression of ATF3 or the combination of ATF3, c-Jun, STAT3 and Smad1 promotes regeneration of the central axon branch of sensory neurons but without synergistic effects. Hum Mol Genet 2015; 24:6788-800. [PMID: 26385639 DOI: 10.1093/hmg/ddv383] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 09/11/2015] [Indexed: 12/26/2022] Open
Abstract
Peripheral nerve injury results in the activation of a number of transcription factors (TFs) in injured neurons, some of which may be key regulators of the regeneration-associated gene (RAG) programme. Among known RAG TFs, ATF3, Smad1, STAT3 and c-Jun have all been linked to successful axonal regeneration and have known functional and physical interactions. We hypothesised that TF expression would promote regeneration of the central axon branch of DRG neurons in the absence of a peripheral nerve lesion and that simultaneous overexpression of multiple RAG TFs would lead to greater effects than delivery of a single TF. Using adeno-associated viral vectors, we overexpressed either the combination of ATF3, Smad1, STAT3 and c-Jun with farnesylated GFP (fGFP), ATF3 only with fGFP, or fGFP only, in DRG neurons and assessed axonal regeneration after dorsal root transection or dorsal column injury and functional improvement after dorsal root injury. ATF3 alone and the combination of TFs promoted faster regeneration in the injured dorsal root. Surprisingly, however, the combination did not perform better than ATF3 alone. Neither treatment was able to induce functional improvement on sensory tests after dorsal root injury or promote regeneration in a dorsal column injury model. The lack of synergistic effects among these factors indicates that while they do increase the speed of axon growth, there may be functional redundancy between these TFs. Because axon growth is considerably less than that seen after a conditioning lesion, it appears these TFs do not induce the full regeneration programme.
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Affiliation(s)
- Nitish D Fagoe
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, Amsterdam 1105BA, The Netherlands and
| | - Callan L Attwell
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, Amsterdam 1105BA, The Netherlands and
| | - Dorette Kouwenhoven
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, Amsterdam 1105BA, The Netherlands and
| | - Joost Verhaagen
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, Amsterdam 1105BA, The Netherlands and Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, De Boelelaan 1085, Amsterdam 1081HV, The Netherlands
| | - Matthew R J Mason
- Laboratory for Neuroregeneration, Netherlands Institute for Neuroscience, an Institute of the Royal Academy of Arts and Sciences, Meibergdreef 47, Amsterdam 1105BA, The Netherlands and
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Oteiza A, Mechti N. Control of FoxO4 Activity and Cell Survival by TRIM22 Directs TLR3-Stimulated Cells Toward IFN Type I Gene Induction or Apoptosis. J Interferon Cytokine Res 2015; 35:859-74. [PMID: 26237181 DOI: 10.1089/jir.2015.0020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Activation of innate immune response, induced after the recognition of double-stranded RNA (dsRNA), formed during replication of most viruses, results in intracellular signaling cascades ultimately culminating in the expression of type I interferon (IFN). In this study, we provide the first evidence that FoxO4 triggers the activation of the innate immune signaling pathway in coupling stimulation of TLR3 and RIG-like receptors by the synthetic dsRNA analog, poly(I:C), to IFN-β and IFN-induced gene induction, whereas knockdown of FoxO4 had opposite effects. Similar effects of FoxO4 were observed during paramyxovirus-mediated IFN-β transcriptional induction. We further found that knockdown of FoxO4 did not affect IRF3 and NF-κB activation by poly(I:C), suggesting that FoxO4 would act downstream in the signaling pathway. In addition, we show that the IFN-induced TRIM22 ubiquitin ligase targets FoxO4 and antagonizes its activity through an unrelated ubiquitin/autophagosomic-lysosomal pathway. Unexpectedly, TRIM22 knockdown strongly sensitizes cells to dsRNA-induced caspase-dependent apoptosis, as early as 2 h after poly(I:C) stimulation, concomitantly to the inhibition of the expression of the antiapoptotic protein, Bcl-2, indicating that TRIM22 might be a key factor for controlling the cell survival after TLR3 stimulation. Taken together, our data demonstrate that the regulation of FoxO4 protein expression and cell survival by TRIM22 controls TLR3-mediated IFN type I gene induction, preventing excessive antiviral response through dsRNA-induced apoptosis.
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Affiliation(s)
- Alexandra Oteiza
- 1 CNRS, UMR5235, DIMNP, University of Montpellier 2 , Montpellier, France .,2 CNRS UMR5236, University of Montpellier 1 and 2 , Montpellier, France
| | - Nadir Mechti
- 1 CNRS, UMR5235, DIMNP, University of Montpellier 2 , Montpellier, France .,2 CNRS UMR5236, University of Montpellier 1 and 2 , Montpellier, France
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López AJ, Wood MA. Role of nucleosome remodeling in neurodevelopmental and intellectual disability disorders. Front Behav Neurosci 2015; 9:100. [PMID: 25954173 PMCID: PMC4407585 DOI: 10.3389/fnbeh.2015.00100] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/06/2015] [Indexed: 12/20/2022] Open
Abstract
It is becoming increasingly important to understand how epigenetic mechanisms control gene expression during neurodevelopment. Two epigenetic mechanisms that have received considerable attention are DNA methylation and histone acetylation. Human exome sequencing and genome-wide association studies have linked several neurobiological disorders to genes whose products actively regulate DNA methylation and histone acetylation. More recently, a third major epigenetic mechanism, nucleosome remodeling, has been implicated in human developmental and intellectual disability (ID) disorders. Nucleosome remodeling is driven primarily through nucleosome remodeling complexes with specialized ATP-dependent enzymes. These enzymes directly interact with DNA or chromatin structure, as well as histone subunits, to restructure the shape and organization of nucleosome positioning to ultimately regulate gene expression. Of particular interest is the neuron-specific Brg1/hBrm Associated Factor (nBAF) complex. Mutations in nBAF subunit genes have so far been linked to Coffin-Siris syndrome (CSS), Nicolaides-Baraitser syndrome (NBS), schizophrenia, and Autism Spectrum Disorder (ASD). Together, these human developmental and ID disorders are powerful examples of the impact of epigenetic modulation on gene expression. This review focuses on the new and emerging role of nucleosome remodeling in neurodevelopmental and ID disorders and whether nucleosome remodeling affects gene expression required for cognition independently of its role in regulating gene expression required for development.
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Affiliation(s)
- Alberto J López
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine Irvine, CA, USA
| | - Marcelo A Wood
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California Irvine Irvine, CA, USA
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Banerjee AR, Kim YJ, Kim TH. A novel virus-inducible enhancer of the interferon-β gene with tightly linked promoter and enhancer activities. Nucleic Acids Res 2014; 42:12537-54. [PMID: 25348400 PMCID: PMC4227751 DOI: 10.1093/nar/gku1018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Long-range enhancers of transcription are a key component of the genomic regulatory architecture. Recent studies have identified bi-directionally transcribed RNAs emanating from these enhancers known as eRNAs. However, it remains unclear how tightly coupled eRNA production is with enhancer activity. Through our systematic search for long-range elements that interact with the interferon-β gene, a model system for studying inducible transcription, we have identified a novel enhancer, which we have named L2 that regulates the expression of interferon-β. We have demonstrated its virus-inducible enhancer activity by analyzing epigenomic profiles, transcription factor association, nascent RNA production and activity in reporter assays. This enhancer exhibits intimately linked virus-inducible enhancer and bidirectional promoter activity that is largely dependent on a conserved Interferon Stimulated Response Element and robustly generates virus inducible eRNAs. Notably, its enhancer and promoter activities are fully retained in reporter assays even upon a complete elimination of its associated eRNA sequences. Finally, we show that L2 regulates IFNB1 expression by siRNA knockdown of eRNAs, and the deletion of L2 in a BAC transfection assay. Thus, L2 is a novel enhancer that regulates IFNB1 and whose eRNAs exert significant activity in vivo that is distinct from those activities recapitulated in the luciferase reporter assays.
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Affiliation(s)
- A Raja Banerjee
- Department of Genetics, Yale University, School of Medicine, New Haven, CT 06520, USA
| | - Yoon Jung Kim
- Department of Genetics, Yale University, School of Medicine, New Haven, CT 06520, USA
| | - Tae Hoon Kim
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75080, USA
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49
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Smith JA. A new paradigm: innate immune sensing of viruses via the unfolded protein response. Front Microbiol 2014; 5:222. [PMID: 24904537 PMCID: PMC4032990 DOI: 10.3389/fmicb.2014.00222] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 04/27/2014] [Indexed: 12/17/2022] Open
Abstract
The immune system depends upon combinations of signals to mount appropriate responses: pathogen specific signals in the context of co-stimulatory “danger” signals drive immune strength and accuracy. Viral infections trigger anti-viral type I interferon (IFN) responses by stimulating endosomal and cytosolic pattern recognition receptors (PRRs). However, viruses have also evolved many strategies to counteract IFN responses. Are there intracellular danger signals that enhance immune responses to viruses? During infection, viruses place a heavy demand on the protein folding machinery of the host endoplasmic reticulum (ER). To survive ER stress, host cells mount an unfolded protein response (UPR) to decrease ER protein load and enhance protein-folding capacity. Viruses also directly elicit the UPR to enhance their replication. Increasing evidence supports an intersection between the host UPR and inflammation, in particular the production of pro-inflammatory cytokines and type I IFN. The UPR directly activates pro-inflammatory cytokine transcription factors and dramatically enhances cytokine production in response to viral PRR engagement. Additionally, viral PRR engagement may stimulate specific pathways within the UPR to enhance cytokine production. Through these mechanisms, viral detection via the UPR and inflammatory cytokine production are intertwined. Consequently, the UPR response is perfectly poised to act as an infection-triggered “danger” signal. The UPR may serve as an internal “co-stimulatory” signal that (1) provides specificity and (2) critically augments responses to overcome viral subterfuge. Further work is needed to test this hypothesis during viral infections.
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Affiliation(s)
- Judith A Smith
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health Madison, WI, USA
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Todeschini AL, Georges A, Veitia RA. Transcription factors: specific DNA binding and specific gene regulation. Trends Genet 2014; 30:211-9. [PMID: 24774859 DOI: 10.1016/j.tig.2014.04.002] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 03/26/2014] [Accepted: 04/01/2014] [Indexed: 12/15/2022]
Abstract
Specific recognition of cis-regulatory regions is essential for correct gene regulation in response to developmental and environmental signals. Such DNA sequences are recognized by transcription factors (TFs) that recruit the transcriptional machinery. Achievement of specific sequence recognition is not a trivial problem; many TFs recognize similar consensus DNA-binding sites and a genome can harbor thousands of consensus or near-consensus sequences, both functional and nonfunctional. Although genomic technologies have provided large-scale snapshots of TF binding, a full understanding of the mechanistic and quantitative details of specific recognition in the context of gene regulation is lacking. Here, we explore the various ways in which TFs recognizing similar consensus sites distinguish their own targets from a large number of other sequences to ensure specific cellular responses.
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Affiliation(s)
| | - Adrien Georges
- Institut Jacques Monod, Paris, France; Université Paris Diderot, Paris, France
| | - Reiner A Veitia
- Institut Jacques Monod, Paris, France; Université Paris Diderot, Paris, France.
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