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Spolski R, Li P, Chandra V, Shin B, Goel S, Sakamoto K, Liu C, Oh J, Ren M, Enomoto Y, West EE, Christensen SM, Wan ECK, Ge M, Lin JX, Yan B, Kazemian M, Yu ZX, Nagao K, Vijayanand P, Rothenberg EV, Leonard WJ. Distinct use of super-enhancer elements controls cell type-specific CD25 transcription and function. Sci Immunol 2023; 8:eadi8217. [PMID: 37922339 PMCID: PMC10832512 DOI: 10.1126/sciimmunol.adi8217] [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: 05/24/2023] [Accepted: 10/10/2023] [Indexed: 11/05/2023]
Abstract
The IL-2 receptor α chain (IL-2Rα/CD25) is constitutively expressed on double-negative (DN2/DN3 thymocytes and regulatory T cells (Tregs) but induced by IL-2 on T and natural killer (NK) cells, with Il2ra expression regulated by a STAT5-dependent super-enhancer. We investigated CD25 regulation and function using a series of mice with deletions spanning STAT5-binding elements. Deleting the upstream super-enhancer region mainly affected constitutive CD25 expression on DN2/DN3 thymocytes and Tregs, with these mice developing autoimmune alopecia, whereas deleting an intronic region decreased IL-2-induced CD25 on peripheral T and NK cells. Thus, distinct super-enhancer elements preferentially control constitutive versus inducible expression in a cell type-specific manner. The mediator-1 coactivator colocalized with specific STAT5-binding sites. Moreover, both upstream and intronic regions had extensive chromatin interactions, and deletion of either region altered the super-enhancer structure in mature T cells. These results demonstrate differential functions for distinct super-enhancer elements, thereby indicating previously unknown ways to manipulate CD25 expression in a cell type-specific fashion.
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Affiliation(s)
- Rosanne Spolski
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Peng Li
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Vivek Chandra
- La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Boyoung Shin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Shubham Goel
- Cutaneous Leukocyte Biology Section, Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Keiko Sakamoto
- Cutaneous Leukocyte Biology Section, Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Hamamatsu University School of Medicine, Department of Dermatology, Hamamatsu, Japan
| | - Chengyu Liu
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jangsuk Oh
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Min Ren
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yutaka Enomoto
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Erin E West
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Stephen M Christensen
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Edwin C K Wan
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Meili Ge
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jian-Xin Lin
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Bingyu Yan
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
| | - Majid Kazemian
- Department of Biochemistry, Purdue University, West Lafayette, IN, USA
| | - Zu-Xi Yu
- Pathology Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Keisuke Nagao
- Cutaneous Leukocyte Biology Section, Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Warren J Leonard
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
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Kuwayama N, Kujirai T, Kishi Y, Hirano R, Echigoya K, Fang L, Watanabe S, Nakao M, Suzuki Y, Ishiguro KI, Kurumizaka H, Gotoh Y. HMGA2 directly mediates chromatin condensation in association with neuronal fate regulation. Nat Commun 2023; 14:6420. [PMID: 37828010 PMCID: PMC10570362 DOI: 10.1038/s41467-023-42094-9] [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: 01/09/2023] [Accepted: 09/27/2023] [Indexed: 10/14/2023] Open
Abstract
Identification of factors that regulate chromatin condensation is important for understanding of gene regulation. High-mobility group AT-hook (HMGA) proteins 1 and 2 are abundant nonhistone chromatin proteins that play a role in many biological processes including tissue stem-progenitor cell regulation, but the nature of their protein function remains unclear. Here we show that HMGA2 mediates direct condensation of polynucleosomes and forms droplets with nucleosomes. Consistently, most endogenous HMGA2 localized to transposase 5- and DNase I-inaccessible chromatin regions, and its binding was mostly associated with gene repression, in mouse embryonic neocortical cells. The AT-hook 1 domain was necessary for chromatin condensation by HMGA2 in vitro and in cellulo, and an HMGA2 mutant lacking this domain was defective in the ability to maintain neuronal progenitors in vivo. Intrinsically disordered regions of other proteins could substitute for the AT-hook 1 domain in promoting this biological function of HMGA2. Taken together, HMGA2 may regulate neural cell fate by its chromatin condensation activity.
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Grants
- This research was supported by AMED-CREST and AMED-PRIME of the Japan Agency for Medical Research and Development (JP22gm1310004, JP22gm6110021), SECOM Science and Technology Foundation SECOM Science and Technology Foundation (for Y.K.), Platform Project for Supporting Drug Discovery and Life Science Research from AMED JP21am0101076 and (for H.K.), Research Support Project for Life Science and Drug Discovery from AMED JP22ama121009 (for H.K.), Japan Science and Technology Agency ERATO JPMJER1901 (for H.K.) and by KAKENHI grants from the Ministry of Education, Culture, Sports, Science, and Technology of Japan and the Japan Society for the Promotion of Science (JP21J14115 for N.K.; JP22K15033 for T.K.;16H06279, 20H03179, 21H00242 and 22H04687 for Y.K.; 20K07589 for S.W.; JP20H00449, JP18H05534 for H.K.; JP22H00431, JP16H06279 and JP22H04925 for Y.G.)
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Affiliation(s)
- Naohiro Kuwayama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Tomoya Kujirai
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Yusuke Kishi
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Rina Hirano
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Kenta Echigoya
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan
| | - Lingyan Fang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Sugiko Watanabe
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Mitsuyoshi Nakao
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Yutaka Suzuki
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, 277-8561, Japan
| | - Kei-Ichiro Ishiguro
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, 860-0811, Japan
| | - Hitoshi Kurumizaka
- Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, 113-0032, Japan.
| | - Yukiko Gotoh
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo, Tokyo, 113-0033, Japan.
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Piotrowska M, Gliwiński M, Trzonkowski P, Iwaszkiewicz-Grzes D. Regulatory T Cells-Related Genes Are under DNA Methylation Influence. Int J Mol Sci 2021; 22:7144. [PMID: 34281195 PMCID: PMC8267835 DOI: 10.3390/ijms22137144] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
Regulatory T cells (Tregs) exert a highly suppressive function in the immune system. Disturbances in their function predispose an individual to autoimmune dysregulation, with a predominance of the pro-inflammatory environment. Besides Foxp3, which is a master regulator of these cells, other genes (e.g., Il2ra, Ctla4, Tnfrsf18, Ikzf2, and Ikzf4) are also involved in Tregs development and function. Multidimensional Tregs suppression is determined by factors that are believed to be crucial in the action of Tregs-related genes. Among them, epigenetic changes, such as DNA methylation, tend to be widely studied over the past few years. DNA methylation acts as a repressive mark, leading to diminished gene expression. Given the role of increased CpG methylation upon Tregs imprinting and functional stability, alterations in the methylation pattern can cause an imbalance in the immune response. Due to the fact that epigenetic changes can be reversible, so-called epigenetic modifiers are broadly used in order to improve Tregs performance. In this review, we place emphasis on the role of DNA methylation of the genes that are key regulators of Tregs function. We also discuss disease settings that have an impact on the methylation status of Tregs and systematize the usefulness of epigenetic drugs as factors able to influence Tregs functions.
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Affiliation(s)
| | | | | | - Dorota Iwaszkiewicz-Grzes
- Department of Medical Immunology, Medical University of Gdansk, 80-210 Gdańsk, Poland; (M.P.); (M.G.); (P.T.)
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The Mammalian High Mobility Group Protein AT-Hook 2 (HMGA2): Biochemical and Biophysical Properties, and Its Association with Adipogenesis. Int J Mol Sci 2020; 21:ijms21103710. [PMID: 32466162 PMCID: PMC7279267 DOI: 10.3390/ijms21103710] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/30/2020] [Accepted: 05/12/2020] [Indexed: 12/11/2022] Open
Abstract
The mammalian high-mobility-group protein AT-hook 2 (HMGA2) is a small DNA-binding protein and consists of three “AT-hook” DNA-binding motifs and a negatively charged C-terminal motif. It is a multifunctional nuclear protein directly linked to obesity, human height, stem cell youth, human intelligence, and tumorigenesis. Biochemical and biophysical studies showed that HMGA2 is an intrinsically disordered protein (IDP) and could form homodimers in aqueous buffer solution. The “AT-hook” DNA-binding motifs specifically bind to the minor groove of AT-rich DNA sequences and induce DNA-bending. HMGA2 plays an important role in adipogenesis most likely through stimulating the proliferative expansion of preadipocytes and also through regulating the expression of transcriptional factor Peroxisome proliferator-activated receptor γ (PPARγ) at the clonal expansion step from preadipocytes to adipocytes. Current evidence suggests that a main function of HMGA2 is to maintain stemness and renewal capacity of stem cells by which HMGA2 binds to chromosome and lock chromosome into a specific state, to allow the human embryonic stem cells to maintain their stem cell potency. Due to the importance of HMGA2 in adipogenesis and tumorigenesis, HMGA2 is considered a potential therapeutic target for anticancer and anti-obesity drugs. Efforts are taken to identify inhibitors targeting HMGA2.
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Belot MP, Castell AL, Le Fur S, Bougnères P. Dynamic demethylation of the IL2RA promoter during in vitro CD4+ T cell activation in association with IL2RA expression. Epigenetics 2018; 13:459-472. [PMID: 30096258 DOI: 10.1080/15592294.2018.1469893] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
IL2RA, a subunit of the high affinity receptor for interleukin-2 (IL2), plays a crucial role in immune homeostasis. Notably, IL2RA expression is induced in CD4+ T cells in response to various stimuli and is constitutive in regulatory T cells (Tregs). We selected for our study 18 CpGs located within cognate regulatory regions of the IL2RA locus and characterized their methylation in naive, regulatory, and memory CD4+ T cells. We found that 5/18 CpGs (notably CpG + 3502) show dynamic, active demethylation during the in vitro activation of naive CD4+ T cells. Demethylation of these CpGs correlates with appearance of IL2RA protein at the cell surface. We found no influence of cis located SNP alleles upon CpG methylation. Treg cells show constitutive demethylation at all studied CpGs. Methylation of 9/18 CpGs, including CpG +3502, decreases with age. Our data thus identify CpG +3502 and a few other CpGs at the IL2RA locus as coordinated epigenetic regulators of IL2RA expression in CD4+ T cells. This may contribute to unravel how the IL2RA locus can be involved in immune physiology and pathology.
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Affiliation(s)
- Marie-Pierre Belot
- a Institut National de la Santé et de la Recherche Médicale UMR1169 , Paris Sud University, Bicêtre Hospital , Le Kremlin-Bicêtre , France.,b Fondation de l'AP-HP pour la Recherche , Paris , France
| | - Anne-Laure Castell
- c Service de Médecine des Adolescents , Paris Sud University, Bicêtre Hospital , Le Kremlin-Bicêtre , France
| | - Sophie Le Fur
- a Institut National de la Santé et de la Recherche Médicale UMR1169 , Paris Sud University, Bicêtre Hospital , Le Kremlin-Bicêtre , France
| | - Pierre Bougnères
- a Institut National de la Santé et de la Recherche Médicale UMR1169 , Paris Sud University, Bicêtre Hospital , Le Kremlin-Bicêtre , France.,c Service de Médecine des Adolescents , Paris Sud University, Bicêtre Hospital , Le Kremlin-Bicêtre , France
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Schulert GS, Zhang M, Husami A, Fall N, Brunner H, Zhang K, Cron RQ, Grom AA. Brief Report: Novel UNC13D Intronic Variant Disrupting an NF-κB Enhancer in a Patient With Recurrent Macrophage Activation Syndrome and Systemic Juvenile Idiopathic Arthritis. Arthritis Rheumatol 2018; 70:963-970. [PMID: 29409136 DOI: 10.1002/art.40438] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 01/30/2018] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Macrophage activation syndrome (MAS) is a life-threatening complication of systemic juvenile idiopathic arthritis (JIA) and has pathologic similarity to hemophagocytic lymphohistiocytosis (HLH). Intronic variants in UNC13D are found in patients with familial HLH type 3 (FHLH3), but the role of noncoding variants in MAS is unknown. The objective of this study was to identify deep intronic UNC13D variants in patients with MAS. METHODS A custom enrichment library was constructed to sequence a genomic region of ~1 Mb flanking UNC13D in 24 patients with systemic JIA, recurrent MAS, and negative results of prior genetic (exon/coding) testing. The functional consequences of intronic variants were assessed using quantitative polymerase chain reaction in patient-derived peripheral blood mononuclear cells (PBMCs), electromobility shift assay, in vitro transcriptional enhancer assays, and natural killer (NK) cell degranulation assays. RESULTS We evaluated a patient with systemic JIA and recurrent MAS in whom a novel functional intronic variant in UNC13D, c.117+143A>G, was observed. This variant occurred in a proposed regulatory region that drives lymphocyte-specific UNC13D expression and is associated with reduced transcript levels in patient PBMCs. This variant also disrupted NF-κB binding to a functional transcriptional enhancer, leading to reduced enhancer activity in vitro. Partial knockdown of UNC13D expression also led to impaired NK cell degranulation. An additional patient was identified with a previously described UNC13D intronic variant, for a total noncoding variant hit rate of 8.3% (2 of 24). CONCLUSION These findings highlight the notion that intronic variants in key regulatory regions may be associated with MAS in patients with systemic JIA and support deep sequencing approaches when causative coding variants are not identified.
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Affiliation(s)
- Grant S Schulert
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Mingce Zhang
- Children's Hospital of Alabama, University of Alabama at Birmingham
| | - Ammar Husami
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Ndate Fall
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Hermine Brunner
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Kejian Zhang
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Randy Q Cron
- Children's Hospital of Alabama, University of Alabama at Birmingham
| | - Alexei A Grom
- Cincinnati Children's Hospital Medical Center and University of Cincinnati College of Medicine, Cincinnati, Ohio
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7
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Huang Y, Cao Y, Li J, Liu Y, Zhong W, Li X, Chen C, Hao P. A survey on cellular RNA editing activity in response to Candida albicans infections. BMC Genomics 2018; 19:43. [PMID: 29363428 PMCID: PMC5780849 DOI: 10.1186/s12864-017-4374-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Background Adenosine-to-Inosine (A-to-I) RNA editing is catalyzed by the adenosine deaminase acting on RNA (ADAR) family of enzymes, which induces alterations in mRNA sequence. It has been shown that A-to-I RNA editing events are of significance in the cell’s innate immunity and cellular response to viral infections. However, whether RNA editing plays a role in cellular response to microorganism/fungi infection has not been determined. Candida albicans, one of the most prevalent human pathogenic fungi, usually act as a commensal on skin and superficial mucosal, but has been found to cause candidiasis in immunosuppression patients. Previously, we have revealed the up-regulation of A-to-I RNA editing activity in response to different types of influenza virus infections. The current work is designed to study the effect of microorganism/fungi infection on the activity of A-to-I RNA editing in infected hosts. Results We first detected and characterized the A-to-I RNA editing events in oral epithelial cells (OKF6) and primary human umbilical vein endothelial cells (HUVEC), under normal growth condition or with C. albicans infection. Eighty nine thousand six hundred forty eight and 60,872 A-to-I editing sites were detected in normal OKF6 and HUVEC cells, respectively. They were validated against the RNA editing databases, DARNED, RADAR, and REDIportal with 50, 80, and 80% success rates, respectively. While over 95% editing sites were detected in Alu regions, among the rest of the editing sites in non repetitive regions, the majority was located in introns and UTRs. The distributions of A-to-I editing activity and editing depth were analyzed during the course of C. albicans infection. While the normalized editing levels of common editing sites exhibited a significant increase, especially in Alu regions, no significant change in the expression of ADAR1 or ADAR2 was observed. Second, we performed further analysis on data from in vivo mouse study with C. albicans infection. One thousand one hundred thirty three and 955 A-to-I editing sites were identified in mouse tongue and kidney tissues, respectively. The number of A-to-I editing events was much smaller than in human epithelial or endothelial cells, due to the lack of Alu elements in mouse genome. Furthermore, during the course of C. albicans infection we observed stable level of A-to-I editing activity in 131 and 190 common editing sites in the mouse tongue and kidney tissues, and found no significant change in ADAR1 or ADAR2 expression (with the exception of ADAR2 displaying a significant increase at 12 h after infection in mouse kidney tissue before returning to normal). Conclusions This work represents the first comprehensive analysis of A-to-I RNA editome in human epithelial and endothelial cells. C. albicans infection of human epithelial and endothelial cells led to the up-regulation of A-to-I editing activities, through a mechanism different from that of viral infections in human hosts. However, the in vivo mouse model with C. albicans infection did not show significant changes in A-to-I editing activities in tongue and kidney tissues. The different results in the mouse model were likely due to the presence of more complex in vivo environments, e.g. circulation and mixed cell types. Electronic supplementary material The online version of this article (10.1186/s12864-017-4374-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yaowei Huang
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 20031, China
| | - Yingying Cao
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 20031, China
| | - Jiarui Li
- Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, 100102, China.,Beijing Key Laboratory of Emerging Infectious Diseases, Beijing, 100102, China
| | - Yuanhua Liu
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 20031, China
| | - Wu Zhong
- National Engineering Research Center For the Emergence Drugs, Beijing Institute of Pharmacology and Toxicology, Beijing, 100850, China
| | - Xuan Li
- Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 20032, China.
| | - Chen Chen
- Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, 100102, China. .,Beijing Key Laboratory of Emerging Infectious Diseases, Beijing, 100102, China.
| | - Pei Hao
- Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, 20031, China.
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Sumter TF, Xian L, Huso T, Koo M, Chang YT, Almasri TN, Chia L, Inglis C, Reid D, Resar LMS. The High Mobility Group A1 (HMGA1) Transcriptome in Cancer and Development. Curr Mol Med 2016; 16:353-93. [PMID: 26980699 DOI: 10.2174/1566524016666160316152147] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 02/15/2016] [Accepted: 03/10/2016] [Indexed: 01/19/2023]
Abstract
BACKGROUND & OBJECTIVES Chromatin structure is the single most important feature that distinguishes a cancer cell from a normal cell histologically. Chromatin remodeling proteins regulate chromatin structure and high mobility group A (HMGA1) proteins are among the most abundant, nonhistone chromatin remodeling proteins found in cancer cells. These proteins include HMGA1a/HMGA1b isoforms, which result from alternatively spliced mRNA. The HMGA1 gene is overexpressed in cancer and high levels portend a poor prognosis in diverse tumors. HMGA1 is also highly expressed during embryogenesis and postnatally in adult stem cells. Overexpression of HMGA1 drives neoplastic transformation in cultured cells, while inhibiting HMGA1 blocks oncogenic and cancer stem cell properties. Hmga1 transgenic mice succumb to aggressive tumors, demonstrating that dysregulated expression of HMGA1 causes cancer in vivo. HMGA1 is also required for reprogramming somatic cells into induced pluripotent stem cells. HMGA1 proteins function as ancillary transcription factors that bend chromatin and recruit other transcription factors to DNA. They induce oncogenic transformation by activating or repressing specific genes involved in this process and an HMGA1 "transcriptome" is emerging. Although prior studies reveal potent oncogenic properties of HMGA1, we are only beginning to understand the molecular mechanisms through which HMGA1 functions. In this review, we summarize the list of putative downstream transcriptional targets regulated by HMGA1. We also briefly discuss studies linking HMGA1 to Alzheimer's disease and type-2 diabetes. CONCLUSION Further elucidation of HMGA1 function should lead to novel therapeutic strategies for cancer and possibly for other diseases associated with aberrant HMGA1 expression.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - L M S Resar
- Department of Medicine, Faculty of the Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Research Building, Room 1025, Baltimore, MD 21205-2109, USA.
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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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Schmidt AM, Zou T, Joshi RP, Leichner TM, Pimentel MA, Sommers CL, Kambayashi T. Diacylglycerol kinase ζ limits the generation of natural regulatory T cells. Sci Signal 2013; 6:ra101. [PMID: 24280042 DOI: 10.1126/scisignal.2004411] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Natural regulatory T (nT(reg)) cells are important for maintaining tolerance to self- and foreign antigens, and they are thought to develop from thymocytes that receive strong T cell receptor (TCR)-mediated signals in the thymus. TCR engagement leads to the activation of phospholipase C-γ1, which generates the lipid second messenger diacylglycerol (DAG) from phosphatidylinositol 4,5-bisphosphate. We used mice that lack the ζ isoform of DAG kinase (DGKζ), which metabolizes DAG to terminate its signaling, to enhance TCR-mediated signaling and identify critical signaling events in nT(reg) cell development. Loss of DGKζ resulted in increased numbers of thymic CD25(+)Foxp3(-)CD4(+) nT(reg) cell precursors and Foxp3(+)CD4(+) nT(reg) cells in a cell-autonomous manner. DGKζ-deficient T cells exhibited increased nuclear translocation of the nuclear factor κB subunit c-Rel, as well as enhanced extracellular signal-regulated kinase (ERK) phosphorylation in response to TCR stimulation, suggesting that these downstream pathways may contribute to nT(reg) cell development. Indeed, reducing c-Rel abundance or blocking ERK phosphorylation abrogated the increased generation of nTreg cells by DGKζ-deficient thymocytes. The extent of ERK phosphorylation correlated with TCR-mediated acquisition of Foxp3 in immature thymocytes in vitro. Furthermore, the development of nT(reg) cells was augmented in mice in which ERK activation was selectively enhanced in T cells. Together, these data suggest that DGKζ regulates the development of nT(reg) cells by limiting the extent of activation of the ERK and c-Rel signaling pathways.
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Affiliation(s)
- Amanda M Schmidt
- 1Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 10194, USA
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Watanabe M, Ni S, Lindenberger AL, Cho J, Tinch SL, Kennedy MA. Characterization of the Stoichiometry of HMGA1/DNA Complexes. Open Biochem J 2013; 7:73-81. [PMID: 24062859 PMCID: PMC3778555 DOI: 10.2174/1874091x01307010073] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 12/09/2011] [Accepted: 12/20/2011] [Indexed: 11/22/2022] Open
Abstract
High-mobility group A1 (HMGA1) non-histone chromatin architectural transcription factors regulate gene expression, embryogenesis, cell differentiation, and adaptive immune responses by binding DNA and other transcription factors. HMGA1 has also been shown to be highly over-expressed in many human cancers and is considered to be a valuable cancer biomarker. Elevated HMGA1 expression levels also make cancer cells resistant to chemotherapy. Here, HMGA1/DNA complex formation was investigated using electrophoretic mobility shift assays (EMSA). Collectively, the EMSA results indicated that full length HMGA1 mixed with DNA containing three AT-hook binding sites formed four distinct HMGA1/DNA complexes ranging in stoichiometry from 1:2 to 3:1 in HMGA1:DNA ratio. The data indicated that the distribution of complexes with different HMGA1 to DNA stoichiometries depended on the molar ratio of HMGA1 to DNA in solution, which could have significant biological implications given that HMGA1 is highly over-expressed in human cancer cells. The two naturally occurring isoforms of HMGA1, HMGA1a and HMGA1b, the latter containing an 11 amino acid deletion between the first and second AT-hooks, were observed to have slightly different DNA binding profiles. Finally, HMGA1 binding affinity to DNA was found to be influenced by the DNA A:T segment sequence context, with higher specificity be observed in HMGA1 binding to TnAn segments, which have two local minor groove minima on either side of the TpA step, compared to An:Tn segments, which have a single minor groove minimum at the 3' end of the An run, implying AT-hook binding favors narrow minor groove structure.
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Affiliation(s)
- Miki Watanabe
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
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12
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Sadighi Akha AA, Theriot CM, Erb-Downward JR, McDermott AJ, Falkowski NR, Tyra HM, Rutkowski DT, Young VB, Huffnagle GB. Acute infection of mice with Clostridium difficile leads to eIF2α phosphorylation and pro-survival signalling as part of the mucosal inflammatory response. Immunology 2013; 140:111-22. [PMID: 23668260 PMCID: PMC3809711 DOI: 10.1111/imm.12122] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 12/22/2022] Open
Abstract
The current study sought to delineate the gene expression profile of the host response in the caecum and colon during acute infection with Clostridium difficile in a mouse model of infection, and to investigate the nature of the unfolded protein response in this process. The infected mice displayed a significant up-regulation in the expression of chemokines (Cxcl1, Cxcl2 and Ccl2), numerous pro-inflammatory cytokines (Ifng, Il1b, Il6, and Il17f), as well as Il22 and a number of anti-microbial peptides (Defa1, Defa28, Defb1, Slpi and Reg3g) at the site(s) of infection. This was accompanied by a significant influx of neutrophils, dendritic cells, cells of the monocyte/macrophage lineage and all major subsets of lymphocytes to these site(s). However, CD4 T cells of the untreated and C. difficile-infected mice expressed similar levels of CD69 and CD25. Neither tissue had up-regulated levels of Tbx21, Gata3 or Rorc. The caeca and colons of the infected mice showed a significant increase in eukaryotic initiation factor 2α (eIF2α) phosphorylation, but neither the splicing of Xbp1 nor the up-regulation of endoplasmic reticulum chaperones, casting doubt on the full-fledged induction of the unfolded protein response by C. difficile. They also displayed significantly higher phosphorylation of AKT and signal transducer and activator of transcription 3 (STAT3), an indication of pro-survival signalling. These data underscore the local, innate, pro-inflammatory nature of the response to C. difficile and highlight eIF2α phosphorylation and the interleukin-22-pSTAT3-RegIIIγ axis as two of the pathways that could be used to contain and counteract the damage inflicted on the intestinal epithelium.
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Affiliation(s)
- Amir A Sadighi Akha
- Divisions of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109-5642, USA
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13
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Eilebrecht S, Wilhelm E, Benecke BJ, Bell B, Benecke AG. HMGA1 directly interacts with TAR to modulate basal and Tat-dependent HIV transcription. RNA Biol 2013; 10:436-44. [PMID: 23392246 DOI: 10.4161/rna.23686] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The transactivating response element (TAR) of human immunodeficiency virus 1 (HIV-1) is essential for promoter transactivation by the viral transactivator of transcription (Tat). The Tat-TAR interaction thereby recruits active positive transcription elongation factor b (P-TEFb) from its inactive, 7SK/HEXIM1-bound form, leading to efficient viral transcription. Here, we show that the 7SK RNA-associating chromatin regulator HMGA1 can specifically bind to the HIV-1 TAR element and that 7SK RNA can thereby compete with TAR. The HMGA1-binding interface of TAR is located within the binding site for Tat and other cellular activators, and we further provide evidence for competition between HMGA1 and Tat for TAR-binding. HMGA1 negatively influences the expression of a HIV-1 promoter-driven reporter in a TAR-dependent manner, both in the presence and in the absence of Tat. The overexpression of the HMGA1-binding substructure of 7SK RNA results in a TAR-dependent gain of HIV-1 promoter activity similar to the effect of the shRNA-mediated knockdown of HMGA1. Our results support a model in which the HMGA1/TAR interaction prevents the binding of transcription-activating cellular co-factors and Tat, subsequently leading to reduced HIV-1 transcription.
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Affiliation(s)
- Sebastian Eilebrecht
- Institut des Hautes Études Scientifiques - Centre National de la Recherche Scientifique; Bures sur Yvette; France & Vaccine Research Institute; Institut Mondor de Recherche Biomédicale; Créteil, France
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14
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Sun H, Guns T, Fierro AC, Thorrez L, Nijssen S, Marchal K. Unveiling combinatorial regulation through the combination of ChIP information and in silico cis-regulatory module detection. Nucleic Acids Res 2012; 40:e90. [PMID: 22422841 PMCID: PMC3384348 DOI: 10.1093/nar/gks237] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Computationally retrieving biologically relevant cis-regulatory modules (CRMs) is not straightforward. Because of the large number of candidates and the imperfection of the screening methods, many spurious CRMs are detected that are as high scoring as the biologically true ones. Using ChIP-information allows not only to reduce the regions in which the binding sites of the assayed transcription factor (TF) should be located, but also allows restricting the valid CRMs to those that contain the assayed TF (here referred to as applying CRM detection in a query-based mode). In this study, we show that exploiting ChIP-information in a query-based way makes in silico CRM detection a much more feasible endeavor. To be able to handle the large datasets, the query-based setting and other specificities proper to CRM detection on ChIP-Seq based data, we developed a novel powerful CRM detection method 'CPModule'. By applying it on a well-studied ChIP-Seq data set involved in self-renewal of mouse embryonic stem cells, we demonstrate how our tool can recover combinatorial regulation of five known TFs that are key in the self-renewal of mouse embryonic stem cells. Additionally, we make a number of new predictions on combinatorial regulation of these five key TFs with other TFs documented in TRANSFAC.
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Affiliation(s)
- Hong Sun
- Department of Microbial and Molecular Systems, Katholieke Universiteit Leuven, Leuven, Belgium
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15
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Dryden NH, Sperone A, Martin-Almedina S, Hannah RL, Birdsey GM, Khan ST, Layhadi JA, Mason JC, Haskard DO, Göttgens B, Randi AM. The transcription factor Erg controls endothelial cell quiescence by repressing activity of nuclear factor (NF)-κB p65. J Biol Chem 2012; 287:12331-42. [PMID: 22337883 PMCID: PMC3320982 DOI: 10.1074/jbc.m112.346791] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The interaction of transcription factors with specific DNA sequences is critical for activation of gene expression programs. In endothelial cells (EC), the transcription factor NF-κB is important in the switch from quiescence to activation, and is tightly controlled to avoid excessive inflammation and organ damage. Here we describe a novel mechanism that controls the activation of NF-κB in EC. The transcription factor Erg, the most highly expressed ETS member in resting EC, controls quiescence by repressing proinflammatory gene expression. Focusing on intercellular adhesion molecule 1(ICAM)-1 as a model, we identify two ETS binding sites (EBS −118 and −181) within the ICAM-1 promoter required for Erg-mediated repression. We show that Erg binds to both EBS −118 and EBS −181, the latter located within the NF-κB binding site. Interestingly, inhibition of Erg expression in quiescent EC results in increased NF-κB-dependent ICAM-1 expression, indicating that Erg represses basal NF-κB activity. Erg prevents NF-κB p65 from binding to the ICAM-1 promoter, suggesting a direct mechanism of interference. Gene set enrichment analysis of transcriptome profiles of Erg and NF-κB-dependent genes, together with chromatin immunoprecipitation (ChIP) studies, reveals that this mechanism is common to other proinflammatory genes, including cIAP-2 and IL-8. These results identify a role for Erg as a gatekeeper controlling vascular inflammation, thus providing an important barrier to protect against inappropriate endothelial activation.
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Affiliation(s)
- Nicola H Dryden
- National Heart and Lung Institute Cardiovascular Sciences Unit, Hammersmith Hospital, Imperial College London, London W12 0NN, UK
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16
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Xi Y, Watanabe S, Hino Y, Sakamoto C, Nakatsu Y, Okada S, Nakao M. Hmga1 is differentially expressed and mediates silencing of the CD4/CD8 loci in T cell lineages and leukemic cells. Cancer Sci 2011; 103:439-47. [PMID: 22106824 DOI: 10.1111/j.1349-7006.2011.02159.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
High-mobility group A1 (Hmga1) protein is an architectural chromatin factor, and aberrant Hmga1 expression in mice causes hematopoietic malignancies with defects in cellular differentiation. However, the functional involvement of Hmga1 in hematopoietic development and leukemic cells remains to be elucidated. Using Hmga1-green fluorescent protein (GFP) knock-in mice that endogenously express an Hmga1-GFP fusion protein, we examined Hmga1 expression in undifferentiated and differentiated populations of hematopoietic cells. During early T cell development in the thymus, Hmga1 is highly expressed in CD4/CD8-double negative (DN) cells and is transiently downregulated in CD4/CD8-double positive (DP) cells. Consistently, Hmga1 directly binds to cis-regulatory elements in the CD4/CD8 loci and the heterochromatin foci in DN-stage cells, but not in DP cells. Interestingly, CD4/CD8 expression in DN-stage leukemic cells is induced by inhibition of Hmga1 binding to nuclear DNA or RNA interference-mediated Hmga1 knockdown. In addition, Hmga1-depleted leukemic T cells markedly diminish proliferation, with transcriptional activation of cyclin-dependent kinase inhibitor genes as a direct target of Hmga1. The data in the present study reveal a role of Hmga1 in transcriptional silencing in T cell lineages and leukemic cells.
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Affiliation(s)
- Yang Xi
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, and Global Center of Excellence Cell Fate Regulation Research and Education Unit, Kumamoto University, Kumamoto, Japan
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Mechanics of the IL2RA gene activation revealed by modeling and atomic force microscopy. PLoS One 2011; 6:e18811. [PMID: 21533205 PMCID: PMC3076448 DOI: 10.1371/journal.pone.0018811] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 03/16/2011] [Indexed: 01/22/2023] Open
Abstract
Transcription implies recruitment of RNA polymerase II and transcription factors (TFs) by DNA melting near transcription start site (TSS). Combining atomic force microscopy and computer modeling, we investigate the structural and dynamical properties of the IL2RA promoter and identify an intrinsically negative supercoil in the PRRII region (containing Elf-1 and HMGA1 binding sites), located upstream of a curved DNA region encompassing TSS. Conformational changes, evidenced by time-lapse studies, result in the progressive positioning of curvature apex towards the TSS, likely facilitating local DNA melting. In vitro assays confirm specific binding of the General Transcription Factors (GTFs) TBP and TFIIB over TATA-TSS position, where an inhibitory nucleosome prevented preinitiation complex (PIC) formation and uncontrolled DNA melting. These findings represent a substantial advance showing, first, that the structural properties of the IL2RA promoter are encoded in the DNA sequence and second, that during the initiation process DNA conformation is dynamic and not static.
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18
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Yang J, Yang W, Hirankarn N, Ye DQ, Zhang Y, Pan HF, Mok CC, Chan TM, Wong RWS, Mok MY, Lee KW, Wong SN, Leung AMH, Li XP, Avihingsanon Y, Rianthavorn P, Deekajorndej T, Suphapeetiporn K, Shotelersuk V, Baum L, Kwan P, Lee TL, Ho MHK, Lee PPW, Wong WHS, Zeng S, Zhang J, Wong CM, Ng IOL, Garcia-Barceló MM, Cherny SS, Tam PKH, Sham PC, Lau CS, Lau YL. ELF1 is associated with systemic lupus erythematosus in Asian populations. Hum Mol Genet 2010; 20:601-7. [PMID: 21044949 DOI: 10.1093/hmg/ddq474] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease with a strong genetic involvement. The susceptibility genes identified so far can only explain a small proportion of disease heritability. Through a genome-wide association in a Hong Kong Chinese cohort and subsequent replication in two other Asian populations, with a total of 3164 patients and 4482 matched controls, we identified association of ELF1 (E74-like factor 1) with SLE (rs7329174, OR = 1.26, joint P= 1.47 × 10(-8)). ELF1 belongs to the ETS family of transcription factors and is known to be involved in T cell development and function. Database analysis revealed transcripts making use of three alternative exon1s for this gene. Near equivalent expression levels of distinct transcripts initiated from alternative exon1s were detected in peripheral blood mononuclear cells from both SLE patients and healthy controls. Although a direct association of rs7329174 with the three forms of transcripts for this gene was not detected, these findings support an important role of ELF1 in SLE susceptibility and suggest a potentially tight regulation for the expression of this gene.
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Affiliation(s)
- Jing Yang
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, LKS Faculty of Medicine,The University of Hong Kong, 21 Sassoon Road, Hong Kong, China
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19
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Amino acid residues in the β3 strand and subsequent loop of the conserved ETS domain that mediate basic leucine zipper (bZIP) recruitment and potentially distinguish functional attributes of Ets proteins. Biochem J 2010; 430:129-39. [DOI: 10.1042/bj20091742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ets family members share a conserved DNA-binding ETS domain, and serve a variety of roles in development, differentiation and oncogenesis. Besides DNA binding, the ETS domain also participates in protein–protein interactions with other structurally unrelated transcription factors. Although this mechanism appears to confer tissue- or development stage-specific functions on individual Ets proteins, the biological significance of many of these interactions remains to be evaluated, because their molecular basis has been elusive. We previously demonstrated a direct interaction between the ETS domain of the widely expressed GABPα (GA-binding protein α) and the granulocyte inducer C/EBPα (CCAAT/enhancer-binding protein α), and suggested its involvement in co-operative transcriptional activation of myeloid-specific genes, such as human FCAR encoding FcαR [Fc receptor for IgA (CD89)]. By deletion analysis, we identified helix α3 and the β3/β4 region as the C/EBPα-interacting region. Domain-swapping of individual sub-domains with those of other Ets proteins allowed us to highlight β-strand 3 and the subsequent loop, which when exchanged by those of Elf-1 (E74-like factor 1) reduced the ability to recruit C/EBPα. Further analysis identified a four-amino acid swap mutation of this region (I387L/C388A/K393Q/F395L) that reduces both physical interaction and co-operative transcriptional activation with C/EBPα without affecting its transactivation capacity by itself. Moreover, re-ChIP (re-chromatin immunoprecipitation) analysis demonstrated that GABPα recruits C/EBPα to the FCAR promoter, depending on these residues. The identified amino acid residues could confer the specificity of the action on the Ets proteins in diverse biological processes through mediating the recruitment of its partner factor.
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20
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Hu Z, Gallo SM. Identification of interacting transcription factors regulating tissue gene expression in human. BMC Genomics 2010; 11:49. [PMID: 20085649 PMCID: PMC2822763 DOI: 10.1186/1471-2164-11-49] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 01/19/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tissue gene expression is generally regulated by multiple transcription factors (TFs). A major first step toward understanding how tissues achieve their specificity is to identify, at the genome scale, interacting TFs regulating gene expression in different tissues. Despite previous discoveries, the mechanisms that control tissue gene expression are not fully understood. RESULTS We have integrated a function conservation approach, which is based on evolutionary conservation of biological function, and genes with highest expression level in human tissues to predict TF pairs controlling tissue gene expression. To this end, we have identified 2549 TF pairs associated with a certain tissue. To find interacting TFs controlling tissue gene expression in a broad spatial and temporal manner, we looked for TF pairs common to the same type of tissues and identified 379 such TF pairs, based on which TF-TF interaction networks were further built. We also found that tissue-specific TFs may play an important role in recruiting non-tissue-specific TFs to the TF-TF interaction network, offering the potential for coordinating and controlling tissue gene expression across a variety of conditions. CONCLUSION The findings from this study indicate that tissue gene expression is regulated by large sets of interacting TFs either on the same promoter of a gene or through TF-TF interaction networks.
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Affiliation(s)
- Zihua Hu
- Center for Computational Research, New York State Center of Excellence in Bioinformatics & Life Sciences, Department of Biostatistics, Department of Medicine, State University of New York (SUNY), Buffalo, NY 14260, USA
| | - Steven M Gallo
- Center for Computational Research, New York State Center of Excellence in Bioinformatics & Life Sciences, State University of New York (SUNY), Buffalo, NY 14260, USA
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21
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Akaboshi SI, Watanabe S, Hino Y, Sekita Y, Xi Y, Araki K, Yamamura KI, Oshima M, Ito T, Baba H, Nakao M. HMGA1 is induced by Wnt/beta-catenin pathway and maintains cell proliferation in gastric cancer. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:1675-85. [PMID: 19729480 PMCID: PMC2751563 DOI: 10.2353/ajpath.2009.090069] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/23/2009] [Indexed: 01/12/2023]
Abstract
The development of stomach cancer is closely associated with chronic inflammation, and the Wnt/beta-catenin signaling pathway is activated in most cases of this cancer. High-mobility group A (HMGA) proteins are oncogenic chromatin factors that are primarily expressed not only in undifferentiated tissues but also in various tumors. Here we report that HMGA1 is induced by the Wnt/beta-catenin pathway and maintains proliferation of gastric cancer cells. Specific knockdown of HMGA1 resulted in marked reduction of cell growth. The loss of beta-catenin or its downstream c-myc decreased HMGA1 expression, whereas Wnt3a treatment increased HMGA1 and c-myc transcripts. Furthermore, Wnt3a-induced expression of HMGA1 was inhibited by c-myc knockdown, suggesting that HMGA1 is a downstream target of the Wnt/beta-catenin pathway. Enhanced expression of HMGA1 coexisted with the nuclear accumulation of beta-catenin in about 30% of gastric cancer tissues. To visualize the expression of HMGA1 in vivo, transgenic mice expressing endogenous HMGA1 fused to enhanced green fluorescent protein were generated and then crossed with K19-Wnt1/C2mE mice, which develop gastric tumors through activation of both the Wnt and prostaglandin E2 pathways. Expression of HMGA1-enhanced green fluorescent protein was normally detected in the forestomach, along the upper border of the glandular stomach, but its expression was also up-regulated in cancerous glandular stomach. These data suggest that HMGA1 is involved in proliferation and gastric tumor formation via the Wnt/beta-catenin pathway.
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Affiliation(s)
- Shin-ichi Akaboshi
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
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22
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Reeves R. Nuclear functions of the HMG proteins. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1799:3-14. [PMID: 19748605 DOI: 10.1016/j.bbagrm.2009.09.001] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 09/04/2009] [Indexed: 12/12/2022]
Abstract
Although the three families of mammalian HMG proteins (HMGA, HMGB and HMGN) participate in many of the same nuclear processes, each family plays its own unique role in modulating chromatin structure and regulating genomic function. This review focuses on the similarities and differences in the mechanisms by which the different HMG families impact chromatin structure and influence cellular phenotype. The biological implications of having three architectural transcription factor families with complementary, but partially overlapping, nuclear functions are discussed.
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Affiliation(s)
- Raymond Reeves
- School of Molecular Biosciences, Washington State University, Biotechnology/Life Sciences Bldg., Rm. 143, Pullman, WA 99164-7520, USA.
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De Siervi A, De Luca P, Moiola C, Gueron G, Tongbai R, Chandramouli GVR, Haggerty C, Dzekunova I, Petersen D, Kawasaki E, Kil WJ, Camphausen K, Longo D, Gardner K. Identification of new Rel/NFkappaB regulatory networks by focused genome location analysis. Cell Cycle 2009; 8:2093-100. [PMID: 19502793 DOI: 10.4161/cc.8.13.8926] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
NFkappaB is an inducible transcription factor that controls kinetically complex patterns of gene expression. Several studies reveal multiple pathways linking NFkappaB to the promotion and progression of various cancers. Despite extensive interest and characterization, many NFkappaB controlled genes still remain to be identified. We used chromatin immunoprecipitation combined with microarray technology (ChIP/chip) to investigate the dynamic interaction of NFkappaB with the promoter regions of 100 genes known to be expressed in mitogen-induced T-cells. Six previously unrecognized NFkappaB controlled genes (ATM, EP300, TGFbeta, Selectin, MMP-1 and SFN) were identified. Each gene is induced in mitogen-stimulated T-cells, repressed by pharmacological NFkappaB blockade, reduced in cells deficient in the p50 NFkappaB subunit and dramatically repressed by RNAi specifically designed against cRel. A coregulatory role for Ets transcription factors in the expression of the NFkappaB controlled genes was predicted by comparative promoter analysis and confirmed by ChIP and by functional disruption of Ets. NFkappaB deficiency produces a deficit in ATM function and DNA repair indicating an active role for NFkappaB in maintaining DNA integrity. These results define new potential targets and transcriptional networks governed by NFkappaB and provide novel functional insights for the role of NFkappaB in genomic stability, cell cycle control, cell-matrix and cell-cell interactions during tumor progression.
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Affiliation(s)
- Adriana De Siervi
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, Bethesda, MD 20892, USA.
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25
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Shiota M, Izumi H, Miyamoto N, Onitsuka T, Kashiwagi E, Kidani A, Hirano G, Takahashi M, Ono M, Kuwano M, Naito S, Sasaguri Y, Kohno K. Ets regulates peroxiredoxin1 and 5 expressions through their interaction with the high-mobility group protein B1. Cancer Sci 2008; 99:1950-9. [PMID: 19016754 PMCID: PMC11159958 DOI: 10.1111/j.1349-7006.2008.00912.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 06/02/2008] [Accepted: 06/08/2008] [Indexed: 01/12/2023] Open
Abstract
Peroxiredoxins (Prdxs) are thiol-specific antioxidant proteins that are highly expressed in human cancer cells. Prdxs have been shown to be involved in tumor cell proliferation under conditions of microenvironmental stress such as hypoxia. We hypothesized that Prdxs could be categorized into two groups, stress-inducible and non-inducible ones. In this study, we analyzed the promoter activity and expression levels of five Prdx family members in human cancer cells. We found that both Prdx1 and Prdx5 are inducible after treatment with hydrogen peroxide or hypoxia, but that Prdx2, Prdx3, and Prdx4 are not or are only marginally inducible. We also found that Ets transcription factors are the key activators for stress-inducible expression. High-mobility group protein HMGB1 was shown to function as a coactivator through direct interactions with Ets transcription factors. The DNA binding of Ets transcription factors was significantly enhanced by HMGB1. Silencing of Ets1, Ets2, Prdx1, and Prdx5 expression sensitized cells to oxidative stress. These data indicate that transcription of Prdx genes mediated by Ets/HMG proteins might protect cells from oxidative stress.
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Affiliation(s)
- Masaki Shiota
- Department of Molecular Biology, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan
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Krishna D, Raykin J, Le Doux JM. Targeted Receptor Trafficking Affects the Efficiency of Retrovirus Transduction. Biotechnol Prog 2008; 21:263-73. [PMID: 15903265 DOI: 10.1021/bp049767b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the development of an experimental system to test the hypothesis that the efficiency of retrovirus transduction is dependent on the pathway of virus entry into the host cell and the intracellular trafficking itinerary of the cellular receptor with which it interacts. The experimental system consists of three model target cell lines, derived from HeLa cells, that stably express one of three interleukin-2 receptor alpha chain (CD25) chimeras, TAC, TAC-CD16, and TAC-DKQTLL, which have identical extracellular domains but different intracellular trafficking itineraries, and a targeted amphotropic murine leukemia retrovirus whose envelope proteins were modified to include a binding site for TAC at their N-termini. We found that the efficiency of retrovirus transduction was affected by the distribution and trafficking itinerary of the TAC receptors. Transduction of cells that expressed TAC-DKQTLL was nearly 4-fold lower than transduction of control cells that did not express any of the TAC receptors. In contrast, transduction of cells that expressed TAC was 1.6-fold higher than transduction of control cells, whereas transduction was not significantly affected by the expression of TAC-CD16. Our results suggest that in the course of designing a targeted retrovirus it may be prudent to target only those receptors that internalize retroviruses via pathways that most efficiently support post-binding steps of infection.
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Affiliation(s)
- Delfi Krishna
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0535, USA
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Liau SS, Rocha F, Matros E, Redston M, Whang E. High mobility group AT-hook 1 (HMGA1) is an independent prognostic factor and novel therapeutic target in pancreatic adenocarcinoma. Cancer 2008; 113:302-14. [PMID: 18473350 DOI: 10.1002/cncr.23560] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND High mobility group AT-hook 1 (HMGA1) proteins are architectural transcription factors that are overexpressed by pancreatic adenocarcinomas. The authors hypothesized that tumor HMGA1 status represents a novel prognostic marker in pancreatic adenocarcinoma. They also tested the hypothesis that HMGA1 promotes anchorage-independent cellular proliferation and in vivo tumorigenicity. METHODS Tumor HMGA1 expression was examined by immunohistochemical analysis of tissues from 89 consecutive patients who underwent resection for pancreatic adenocarcinoma. Short-hairpin RNA (shRNA)-mediated RNA interference was used to silence HMGA1 expression in MiaPaCa2 and PANC1 pancreatic cancer cells. Anchorage-independent proliferation was assessed by using soft agar assays. The roles of phosphatidylinositol 3-kinase (PI3-K)/Akt and extracellular signal-regulated kinase (ERK) signaling were investigated by using specific inhibitors and adenoviral dominant-negative/active Akt constructs. In vivo tumorigenicity was assessed by using a nude mouse xenograft model. RESULTS Tumor HMGA1 expression was detected in 93% of patients with pancreatic adenocarcinoma. Patients with HMGA1-negative tumors had a significantly longer median survival than patients with HMGA1-expressing cancers in univariate analysis (P = .0028) and in multivariate analysis (P<.05). shRNA-mediated HMGA1 silencing resulted in significant reductions in anchorage-independent proliferation in soft agar. Forced HMGA1 overexpression promoted proliferation in soft agar through a process that was dependent on PI3-K/Akt-activited signaling, but not on mitogen-activated protein kinase (MEK)/ERK signaling. Targeted silencing of HMGA1 reduced tumor growth in vivo through reduced proliferation (Ki-67 index) and increased apoptosis (terminal deoxynucleotidyl transferase nick-end labeling). CONCLUSIONS The current findings suggested that HMGA1 is an independent predictor of poor postoperative survival in patients with pancreatic adenocarcinoma. Furthermore, HMGA1 promotes tumorigenicity through a PI3-K/Akt-dependent mechanism. HMGA1 warrants further evaluation as a prognostic marker and therapeutic target in pancreatic cancer.
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Affiliation(s)
- Siong-Seng Liau
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Liau SS, Whang E. HMGA1 is a molecular determinant of chemoresistance to gemcitabine in pancreatic adenocarcinoma. Clin Cancer Res 2008; 14:1470-7. [PMID: 18316571 PMCID: PMC2652398 DOI: 10.1158/1078-0432.ccr-07-1450] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE HMGA1 proteins are architectural transcription factors that are overexpressed by pancreatic adenocarcinomas. We previously have shown that RNA interference targeting the HMGA1 gene may represent a potential chemosensitizing strategy in pancreatic adenocarcinoma cells. In this study, we tested the hypothesis that HMGA1 promotes chemoresistance to gemcitabine in pancreatic cancer cells. EXPERIMENTAL DESIGN AND RESULTS Stable short hairpin RNA-mediated HMGA1 silencing in BxPC3 and MiaPaCa2 cells promoted chemosensitivity to gemcitabine, with reductions in gemcitabine IC(50) and increases in gemcitabine-induced apoptosis and caspase-3 activation. In contrast, forced HMGA1 overexpression in MiaPaCa2 cells promoted chemoresistance to gemcitabine, with increases in gemcitabine IC(50) and reductions in gemcitabine-induced apoptosis and caspase-3 activation. Dominant negative Akt abrogated HMGA1 overexpression-induced increases in chemoresistance to gemcitabine. Finally, HMGA1 silencing promoted chemosensitivity to gemcitabine in vivo in a nude mouse xenograft model of pancreatic adenocarcinoma. CONCLUSION Our findings suggest that HMGA1 promotes chemoresistance to gemcitabine through an Akt-dependent mechanism. Targeted therapies directed at HMGA1 represent a potential strategy for ameliorating chemoresistance in pancreatic adenocarcinoma.
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Affiliation(s)
- Siong-Seng Liau
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Xiong X, Feng Q, Chen L, Xie L, Zhang R. Cloning and characterization of an IKK homologue from pearl oyster, Pinctada fucata. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:15-25. [PMID: 17568671 DOI: 10.1016/j.dci.2007.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Revised: 03/25/2007] [Accepted: 03/29/2007] [Indexed: 05/15/2023]
Abstract
IkappaB kinase (IKK) play central roles in cell signaling by regulating nuclear factor-kappaB (NF-kappaB) activation, which is involved in inflammatory response, proliferation, development and bone homeostasis. We report here for the first time that an IKK homologue was cloned and functionally characterized in pearl oyster, Pinctada fucata. The full-length cDNA consists of 2546bp with an ORF encoding a 737 amino acids protein. The putative pearl oyster IKK protein (Pf-IKK) possesses the characteristic organization of the mammalian IKK proteins, namely an amino-terminal kinase domain followed by a leucine zipper region and a carboxylterminal helix-loop-helix motif. Real-time PCR (RT-PCR) analysis indicated that Pf-IKK was ubiquitously expressed in pearl oyster. We also found that lipopolysaccharides (LPS) transiently stimulates IkappaBalpha degradation, but not expression levels of Pf-IKK. When transfected into NIH3T3 cells, Pf-IKK activated the expression of NF-kappaB-controlled reporter gene and induced NF-kappaB translocation, whereas the activation was greatly deduced by pyrrolidine dithiocarbamate (PDTC). We also found that overexpression of Pf-IKK increased the alkaline phosphatase (ALP) activity significantly. Based on the results and the homology to the vertebrate NF-kappaB cascade, these studies help to highlight a potentially important regulatory pathway to the study of the related functions in mollusks.
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Affiliation(s)
- Xunhao Xiong
- Institute of Marine Biotechnology, Department of Biological Science and Biotechnology, Tsinghua University, Beijing, 100084, China
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30
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Kumar K, Singal A, Rizvi MMA, Chauhan VS. High mobility group box (HMGB) proteins of Plasmodium falciparum: DNA binding proteins with pro-inflammatory activity. Parasitol Int 2007; 57:150-7. [PMID: 18234548 DOI: 10.1016/j.parint.2007.11.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 11/21/2007] [Accepted: 11/23/2007] [Indexed: 11/17/2022]
Abstract
High mobility group box chromosomal protein 1 (HMGB1), known as an abundant, non-histone architectural chromosomal protein, is highly conserved across different species. Homologues of HMGB1 were identified and cloned from malaria parasite, Plasmodium falciparum. Sequence analyses showed that the P. falciparum HMGB1 (PfHMGB1) exhibits 45, 23 and 18%, while PfHMGB2 shares 42, 21 and 17% homology with Saccharomyces cerevisiae, human and mouse HMG box proteins respectively. Parasite PfHMGB1and PfHMGB2 proteins contain one HMG Box domain similar to B-Box of mammalian HMGB1. Electrophoretic Mobility Shift Assay (EMSA) showed that recombinant PfHMGB1 and PfHMGB2 bind to DNA. Immunofluorescence Assay using specific antibodies revealed that these proteins are expressed abundantly in the ring stage nuclei. Significant levels of PfHMGB1 and PfHMGB2 were also present in the parasite cytosol at trophozoite and schizont stages. Both, PfHMGB1 and PfHMGB2 were found to be potent inducers of pro-inflammatory cytokines such as TNFalpha from mouse peritoneal macrophages as analyzed by both reverse transcription PCR and by ELISA. These results suggest that secreted PfHMGB1 and PfHMGB2 may be responsible for eliciting/ triggering host inflammatory immune responses associated with malaria infection.
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Affiliation(s)
- Krishan Kumar
- International Centre of Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi-110067, India
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Milani P, Marilley M, Rocca-Serra J. TBP binding capacity of the TATA box is associated with specific structural properties: AFM study of the IL-2R alpha gene promoter. Biochimie 2006; 89:528-33. [PMID: 17336441 DOI: 10.1016/j.biochi.2006.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2006] [Accepted: 12/12/2006] [Indexed: 11/27/2022]
Abstract
DNA is not only a nucleotide sequence which allows the binding of regulators but its intrinsic structural properties such as curvature and flexibility are also viewed as playing an active role in the regulation of transcription. Our combination of computer modelling and AFM imaging allow direct access to DNA curvature and flexibility. We have searched for these DNA structural features involved in transcription regulation within the IL-2Ralpha gene promoter. Investigation of these structural characteristics shows concordant results. First, in the core promoter, the region containing the functional TATA box shows intrinsic curvature associated with a peculiar distribution of flexibility. Both these inherent properties are characteristic of this region as compared with the other parts of the promoter. Second, the proximal promoter exhibits two important regions: a first one flexible and curved, followed by a segment of rigid linear DNA, each localised within one of the two Positive Regulatory Regions PRRI and PRRII respectively. Based on these observations, we propose different roles for DNA curvature and/or flexibility in promoter sequences.
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Affiliation(s)
- Pascale Milani
- RGFCP EA 3290, Faculté de Médecine, Université de la Méditerranée, 27, Bvd Jean Moulin, 13385 Marseille cedex 5, France.
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Sadighi Akha AA, Berger SB, Miller RA. Enhancement of CD8 T-cell function through modifying surface glycoproteins in young and old mice. Immunology 2006; 119:187-94. [PMID: 16805788 PMCID: PMC1782347 DOI: 10.1111/j.1365-2567.2006.02420.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Previous work from our laboratory has shown that modifying cell surface glycosylation with either a Clostridium perfringens-derived sialidase (CP-Siase), or an O-linked glycoprotein endopeptidase (OSGE) can enhance the function of CD4 T cells from both young and old mice at multiple levels. Here we have re-assessed the effect of age on CD8 T-cell function, and examined the outcome of enzymatic treatment with CP-Siase and OSGE on its different aspects. Pre-treatment of CD8 T cells with either CP-Siase or OSGE led to a significant increase in anti-CD3-mediated Ca2+ response in both young and old mice. Pre-treated CD8 T cells from both age groups also displayed a significant increase in activation-induced CD69 and CD25 expression, and produced significantly higher amounts of interleukin-2 and interferon-gamma in comparison to their untreated counterparts. Furthermore, pretreatment with either enzyme enhanced granzyme B expression in CD8 T cells, and increased their cytolytic activity in vitro. These data support the notion that glycosylated surface proteins hinder CD8 T-cell activation and function in both young and old mice, and raise the possibility of significantly improving CD8 T cell function in older individuals through enzymatic alteration of surface glycoproteins.
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Affiliation(s)
- Amir A Sadighi Akha
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA.
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Liau SS, Ashley SW, Whang EE. Lentivirus-mediated RNA interference of HMGA1 promotes chemosensitivity to gemcitabine in pancreatic adenocarcinoma. J Gastrointest Surg 2006; 10:1254-62; discussion 1263. [PMID: 17114012 DOI: 10.1016/j.gassur.2006.06.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2006] [Accepted: 06/20/2006] [Indexed: 01/31/2023]
Abstract
The high mobility group A1 (HMGA1) proteins are overexpressed in pancreatic cancers. They are architectural nuclear proteins, which regulate expression of multiple genes implicated in the malignant phenotype. In this study, we hypothesized that HMG A1 silencing will promote chemosensitivity in pancreatic adenocarcinoma. We studied highly malignant pancreatic adenocarcinoma cell lines (MiaPaCa2 and PANC1). Lentiviral short-hairpin RNA (shHMGA1) expression vectors targeting HMGA1 were used for generation of lentiviral particles. Stable transfectants were developed after lentiviral transduction. Nuclear expression of HMGA1 was assayed using Western blot analysis. Chemosensitivity to gemcitabine was determined by IC50 analysis. Caspase activity was quantitated using fluorometric caspase profiling. Apoptosis was assessed by flow cytometric analysis. Lentivirus-mediated RNA interference resulted in 90% silencing of HMGA1 expression in each of MiaPaCa2 and PANC1 cell lines. HMGA1 silencing enhanced chemosensitivity to gemcitabine with an approximately 50% reduction in IC50 in each cell line. Lentivirus-mediated HMGA1 silencing promoted the activation of caspases 3, 2, 9, and 8, on exposure to gemcitabine. HMGA1 silencing resulted in reduction in Akt kinase activity. Lentivirus-mediated RNA interference of HMGA1 promoted chemosensitivity to gemcitabine in pancreatic adenocarcinoma. HMGA1 may represent a novel therapeutic target in pancreatic cancer.
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Affiliation(s)
- Siong-Seng Liau
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Kim HP, Imbert J, Leonard WJ. Both integrated and differential regulation of components of the IL-2/IL-2 receptor system. Cytokine Growth Factor Rev 2006; 17:349-66. [PMID: 16911870 DOI: 10.1016/j.cytogfr.2006.07.003] [Citation(s) in RCA: 229] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Interleukin-2 was discovered in 1976 as a T-cell growth factor. It was the first type I cytokine cloned and the first for which a receptor component was cloned. Its importance includes its multiple actions, therapeutic potential, and lessons for receptor biology, with three components differentially combining to form high, intermediate, and low-affinity receptors. IL-2Ralpha and IL-2Rbeta, respectively, are markers for double-negative thymocytes and regulatory T-cells versus memory cells. gamma(c), which is shared by six cytokines, is mutated in patients with X-linked severe-combined immunodeficiency. We now cover an under-reviewed area-the regulation of genes encoding IL-2 and IL-2R components, with an effort to integrate/explain this knowledge.
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Affiliation(s)
- Hyoung Pyo Kim
- Laboratory of Molecular Immunology, Immunology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1674, United States.
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35
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Fedele M, Fidanza V, Battista S, Pentimalli F, Klein-Szanto AJP, Visone R, De Martino I, Curcio A, Morisco C, Del Vecchio L, Baldassarre G, Arra C, Viglietto G, Indolfi C, Croce CM, Fusco A. Haploinsufficiency of theHmga1Gene Causes Cardiac Hypertrophy and Myelo-Lymphoproliferative Disorders in Mice. Cancer Res 2006; 66:2536-43. [PMID: 16510570 DOI: 10.1158/0008-5472.can-05-1889] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The HMGA1 protein is a major factor in chromatin architecture and gene control. It plays a critical role in neoplastic transformation. In fact, blockage of HMGA1 synthesis prevents rat thyroid cell transformation by murine transforming retroviruses, and an adenovirus carrying the HMGA1 gene in the antisense orientation induces apoptotic cell death in anaplastic human thyroid carcinoma cell lines, but not in normal thyroid cells. Moreover, both in vitro and in vivo studies have established the oncogenic role of the HMGA1 gene. In this study, to define HMGA1 function in vivo, we examined the consequences of disrupting the Hmga1 gene in mice. Both heterozygous and homozygous mice for the Hmga1-null allele show cardiac hypertrophy due to the direct role of HMGA1 on cardiomyocytic cell growth regulation. These mice also developed hematologic malignancies, including B cell lymphoma and myeloid granuloerythroblastic leukemia. The B cell expansion and the increased expression of the RAG1/2 endonuclease, observed in HMGA1-knockout spleen tissues, might be responsible for the high rate of abnormal IgH rearrangements observed in these neoplasias. Therefore, the data reported here indicate the critical role of HMGA1 in heart development and growth, and reveal an unsuspected antioncogenic potential for this gene in hematologic malignancies.
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Affiliation(s)
- Monica Fedele
- Istituto di Endocrinologia ed Oncologia Sperimentale del Consiglio Nazionale delle Ricerche c/o Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II, Italy
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36
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Ganster RW, Guo Z, Shao L, Geller DA. Differential effects of TNF-alpha and IFN-gamma on gene transcription mediated by NF-kappaB-Stat1 interactions. J Interferon Cytokine Res 2006; 25:707-19. [PMID: 16318585 DOI: 10.1089/jir.2005.25.707] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Regulation of gene transcription by the cytokines tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) involves complex interactions between NF-kappaB and Stat families of transcription factors. The purpose of this study was to identify the spatial promoter requirements that govern cytokine synergy for gene transcription regulated by NF-kappaB and Stat factors. Using a set of transcription reporter-luciferase constructs, we show that the relative orientation of juxtaposed NF-kappaB-Stat (SIE) cis-elements determines the ability of TNF-alpha and IFN- gamma to induce gene transcription. Further, NF-kappaB and Stat1 proteins directly regulate transcription by interacting cooperatively on NF-kappaB-SIE DNA binding in response to TNF-alpha plus IFN-gamma. Coimmunoprecipitation provides evidence for a direct NF-kappaB/Stat1 protein-protein interaction. In contrast, IFN-gamma inhibits TNF-alpha-induced transcription of an NF-kappaB reporter gene in a Stat1-dependent mechanism in 2fTGH fibroblasts. Similarly, Stat1 is inhibitory to NF-kappaB overexpression-induced transcription. IFN-gamma and Stat1-dependent inhibition of NF-kappaB transcription occurs independent of TNF-alpha-induced NF-kappaB DNA binding. Interestingly, IFN-gamma pretreatment of 2fTGH fibroblasts potentiates TNF-alpha induction of Stat1 DNA binding. Further, ChIP analysis was applied to detect cytokine-induced in vivo binding and transcriptional regulation of the human inducible nitric oxide synthase (iNOS) gene by NF-kappaB and Stat1. These data demonstrate complex transcriptional regulatory mechanisms elicited by TNF-alpha and IFN-gamma and have potentially important implications for other genes differentially controlled by cytokines.
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Affiliation(s)
- Raymond W Ganster
- Department of Surgery, University of Pittsburgh School of Medicine, PA 15261, USA
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37
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Bunting K, Wang J, Shannon MF. Control of interleukin-2 gene transcription: a paradigm for inducible, tissue-specific gene expression. VITAMINS AND HORMONES 2006; 74:105-45. [PMID: 17027513 DOI: 10.1016/s0083-6729(06)74005-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Interleukin-2 (IL-2) is a key cytokine that controls immune cell function, in particular the adaptive arm of the immune system, through its ability to control the clonal expansion and homeostasis of peripheral T cells. IL-2 is produced almost exclusively by T cells in response to antigenic stimulation and thus provides an excellent example of a cell-specific inducible gene. The mechanisms that control IL-2 gene transcription have been studied in detail for the past 20 years and our current understanding of the nature of the inducible and tissue-specific controls will be discussed.
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Affiliation(s)
- Karen Bunting
- Division of Molecular Bioscience, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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Battista S, Fedele M, Hoyos J, Pentimalli F, Pierantoni G, Visone R, De Martino I, Croce C, Fusco A. High-mobility-group A1 (HMGA1) proteins down-regulate the expression of the recombination activating gene 2 (RAG2). Biochem J 2005; 389:91-7. [PMID: 15713121 PMCID: PMC1184541 DOI: 10.1042/bj20041607] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
HMGA1 (high-mobility-group A1) proteins are architectural transcription factors that are found overexpressed in embryogenesis and malignant tumours. We have shown previously that they have a role in lymphopoiesis, since the loss of HMGA1 expression leads to an impairment of T-cell development and to an increase in B-cell population. Since RAGs (recombination activating genes) are key regulators of lymphoid differentiation, in the present study we investigate whether RAG2 expression is dependent on HMGA1 activity. We show that RAG2 gene expression is up-regulated in Hmga1-/- ES (embryonic stem) cells and EBs (embryoid bodies) as well as in yolk sacs and fibroblasts from Hmga1-/- mice, suggesting that HMGA1 proteins control RAG2 gene expression both in vitro and in vivo. We show that the effect of HMGA1 on RAG2 expression is direct, identify the responsible region in the RAG2 promoter and demonstrate binding to the promoter in vivo using chromatin immunoprecipitation. Since RAG2 is necessary for lymphoid cell development, our results suggest a novel mechanism by which HMGA1 might regulate lymphoid differentiation.
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Affiliation(s)
- Sabrina Battista
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Monica Fedele
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Josefina Martinez Hoyos
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Francesca Pentimalli
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Giovanna Maria Pierantoni
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Rosa Visone
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Ivana De Martino
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
| | - Carlo Maria Croce
- †Kimmel Cancer Center, Thomas Jefferson University, 233 S 10th Street, Philadelphia, PA 19107, U.S.A
| | - Alfredo Fusco
- *Dipartimento di Biologia e Patologia Cellulare e Molecolare e/o Istituto di Endocrinologia ed Oncologia Sperimentale del CNR, Facoltà di Medicina e Chirurgia di Napoli, Università degli Studi di Napoli ‘Federico II’, via Pansini, 5, 80131 Naples, Italy
- ‡NOGEC (Naples Oncogenomic Center)–CEINGE, Biotecnologie Avanzate, via Comunale Margherita 482, 80145, Naples, Italy
- To whom correspondence should be addressed, at Dipartimento di Biologia e Patologia Cellulare e Molecolare (email )
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Lu Y, Sheng DQ, Mo ZC, Li HF, Wu NH, Shen YF. A negative regulatory element-dependent inhibitory role of ITF2B on IL-2 receptor alpha gene. Biochem Biophys Res Commun 2005; 336:142-9. [PMID: 16126178 DOI: 10.1016/j.bbrc.2005.08.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 08/05/2005] [Indexed: 11/23/2022]
Abstract
Despite the fact that the negative regulatory element (NRE) within the upstream regulatory region of human IL-2 receptor alpha (IL-2Ralpha) gene has been identified two decades ago, mechanisms of the NRE function on the gene are hitherto unknown. In this paper, we report for the first time that the immunoglobulin transcription factor 2B (ITF2B) encoded by transcription factor 4 (TCF4) gene is a NRE binding protein. The full-length TCF4 cDNA clone was obtained from a HTLV-1 transformed human peripheral T cell MACHERMAKER cDNA library with NRE as the bait in yeast one-hybrid system. The NRE binding ability of ITF2B was further confirmed in chromatin-immunoprecipitation assay. Competitive RT-PCR-based promoter activity assay showed that over-expression of ITF2B protein inhibited the expression of IL-2Ralpha gene in Jurkat cells in an NRE-dependent manner. The function of ITF2B on the inhibition of both the IL-2Ralpha and the 5'LTR activity of HIV-1 shed light on the essence of NRE binding protein as a potential target for immune therapy and treatment in AIDS patients.
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Affiliation(s)
- Yu Lu
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
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Kim HP, Kim BG, Letterio J, Leonard WJ. Smad-dependent cooperative regulation of interleukin 2 receptor alpha chain gene expression by T cell receptor and transforming growth factor-beta. J Biol Chem 2005; 280:34042-7. [PMID: 16087671 DOI: 10.1074/jbc.m505833200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The interleukin 2 receptor alpha chain (IL-2Ralpha) is a component of high affinity IL-2 receptors and thus critically regulates T cell growth and other lymphoid functions. Five positive regulatory regions together control lineage-restricted and activation-dependent IL-2Ralpha induction in response to antigen and IL-2. We now show that TGF-beta cooperates with T cell receptor (TCR) signaling to increase IL-2Ralpha gene expression. Moreover, we identify a sixth positive regulatory region that regulates IL-2Ralpha expression in cells treated with anti-CD3 + anti-CD28 as well as TGF-beta and show that this region contains binding sites for Smad3, AP-1, and cAMP-responsive element-binding protein/ATF proteins. The importance of Smad complexes is indicated by impaired IL-2Ralpha induction by TGF-beta in CD4+ T cells from both Smad3-/- and Smad4-/- mice. Thus, we have identified a novel positive regulatory region in the IL-2Ralpha gene that mediates TGF-beta-dependent induction of the gene. These findings have implications related to IL-2Ralpha expression on activated T cells and regulatory T cells.
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Affiliation(s)
- Hyoung-Pyo Kim
- Laboratory of Molecular Immunology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892-1674, USA
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Sgarra R, Tessari MA, Di Bernardo J, Rustighi A, Zago P, Liberatori S, Armini A, Bini L, Giancotti V, Manfioletti G. Discovering high mobility group A molecular partners in tumour cells. Proteomics 2005; 5:1494-506. [PMID: 15798993 DOI: 10.1002/pmic.200401028] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
DNA-based activities rely on an extremely coordinated sequence of events performed by several chromatin-associated proteins which act in concert. High Mobility Group A (HMGA) proteins are non-histone architectural nuclear factors that participate in the regulation of specific genes but they are also believed to have a more general role in chromatin dynamics. The peculiarity of these proteins is their flexibility, both in terms of DNA-binding and in protein-protein interactions. Since these proteins act as core elements in the assembly of multiprotein complexes called enhanceosomes, and have already displayed the ability to interact with several different proteins, we started a proteomic approach for the systematic identification of their molecular partners. By a combination of affinity chromatography, two-dimensional gel electrophoresis and mass spectrometry we have identified about twenty putative HMGA interactors which could be roughly assigned to three different classes: mRNA processing proteins, chromatin remodelling related factors and structural proteins. Direct HMGA interaction with some of these proteins was confirmed by glutathione-S-transferase pull-down assays and the HMGA domain involved was mapped. Blot-overlay experiments reveal that members of the HMGA family share most of their molecular partners but, interestingly, it seems that there are some cell-type specific partners. Taken together, these experimental data indicate that HMGA proteins are highly connected nodes in the chromatin protein network. Since these proteins are strongly implicated with cancer development, the identification of molecules able to perturb the HMGA molecular network could be a possible tool to interfere with their oncogenic activity.
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Affiliation(s)
- Riccardo Sgarra
- Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, Trieste, Italy
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42
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Adair JE, Kwon Y, Dement GA, Smerdon MJ, Reeves R. Inhibition of nucleotide excision repair by high mobility group protein HMGA1. J Biol Chem 2005; 280:32184-92. [PMID: 16033759 DOI: 10.1074/jbc.m505600200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The mammalian non-histone "high mobility group" A (HMGA) proteins are the primary nuclear proteins that bind to the minor groove of AT-rich DNA. They may, therefore, influence the formation and/or repair of DNA lesions that occur in AT-rich DNA, such as cyclobutane pyrimidine dimers (CPDs) induced by UV radiation. Employing both stably transfected lines of human MCF7 cells containing tetracycline-regulated HMGA1 transgenes and primary Hs578T tumor cells, which naturally overexpress HMGA1 proteins, we have shown that cells overexpressing HMGA1a protein exhibit increased UV sensitivity. Moreover, we demonstrated that knockdown of intracellular HMGA1 concentrations via two independent methods abrogated this sensitivity. Most significantly, we observed that HMGA1a overexpression inhibited global genomic nucleotide excision repair of UV-induced CPD lesions in MCF-7 cells. Consistent with these findings in intact cells, DNA repair experiments employing Xenopus oocyte nuclear extracts and lesion-containing DNA substrates demonstrated that binding of HMGA1a markedly inhibits removal of CPDs in vitro. Furthermore, UV "photo-foot-printing" demonstrated that CPD formation within a long run of Ts (T(18)-tract) in a DNA substrate changes significantly when HMGA1 is bound prior to UV irradiation. Together, these results suggest that HMGA1 directly influences both the formation and repair of UV-induced DNA lesions in intact cells. These findings have important implications for the role that HMGA protein overexpression might play in the accumulation of mutations and genomic instabilities associated with many types of human cancers.
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Affiliation(s)
- Jennifer E Adair
- School of Molecular Biosciences, Biochemistry, and Biophysics, Washingston State University, Pullman, 99164-4660, USA
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43
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Sandberg AA. Updates on the cytogenetics and molecular genetics of bone and soft tissue tumors: leiomyoma. ACTA ACUST UNITED AC 2005; 158:1-26. [PMID: 15771900 DOI: 10.1016/j.cancergencyto.2004.08.025] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 08/11/2004] [Accepted: 08/11/2004] [Indexed: 12/22/2022]
Affiliation(s)
- Avery A Sandberg
- Department of DNA Diagnostics, St. Joseph's Hospital and Medical Center, 350 West Thomas Road, Phoenix, AZ 85013, USA.
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44
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Odero MD, Grand FH, Iqbal S, Ross F, Roman JP, Vizmanos JL, Andrieux J, Laï JL, Calasanz MJ, Cross NCP. Disruption and aberrant expression of HMGA2 as a consequence of diverse chromosomal translocations in myeloid malignancies. Leukemia 2005; 19:245-52. [PMID: 15618963 DOI: 10.1038/sj.leu.2403605] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chromosomal translocations that target HMGA2 at chromosome band 12q14 are seen in a variety of malignancies, notably lipoma, pleomorphic salivary adenoma and uterine leiomyoma. Although some HMGA2 fusion genes have been reported, several lines of evidence suggest that the critical pathogenic event is the expression of truncated HMGA2 isoforms. We report here the involvement of HMGA2 in six patients with myeloid neoplasia, dysplastic features and translocations or an inversion involving chromosome bands 12q13-15 and either 7p12, 8q22, 11q23, 12p11, 14q31 or 20q11. Breaks within or very close to HMGA2 were found in all six cases by molecular cytogenetic analysis, leading to overexpression of this gene as assessed by RT-PCR. Truncated transcripts consisting of HMGA2 exons 1-2 or exons 1-3 spliced to intron-derived sequences were identified in two patients, but were not seen in controls. These findings suggest that abnormalities of HMGA2 play an important and previously unsuspected role in myelodysplasia.
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Affiliation(s)
- M D Odero
- Department of Genetics, School of Science, University of Navarra, Pamplona, Spain
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45
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Xue HH, Bollenbacher J, Rovella V, Tripuraneni R, Du YB, Liu CY, Williams A, McCoy JP, Leonard WJ. GA binding protein regulates interleukin 7 receptor alpha-chain gene expression in T cells. Nat Immunol 2004; 5:1036-44. [PMID: 15361867 DOI: 10.1038/ni1117] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2004] [Accepted: 08/13/2004] [Indexed: 11/08/2022]
Abstract
The interleukin 7 receptor alpha-chain (IL-7Ralpha) is essential for T cell development in both humans and mice and for B cell development in mice. Whereas the transcription factor PU.1 regulates IL-7Ralpha expression in mouse pro-B cells via a GGAA motif, we demonstrate here that GA binding protein (GABP) bound to this site and was essential in the regulation of IL-7Ralpha expression in T cells, where PU.1 is not expressed. Moreover, IL-7Ralpha expression was diminished substantially in thymocytes but was normal on B220(+) fetal liver cells from mouse embryos with diminished expression of GABPalpha. Thus, GABP is essential for the regulation of IL-7Ralpha expression in T cells, and the differential regulation of IL-7Ralpha in distinct lymphoid lineages is achieved at least in part by differential recruitment of factors to the same GGAA motif.
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Affiliation(s)
- Hai-Hui Xue
- Laboratory of Molecular Immunology, National Heart, Lung, and Blood Institute, National Institutes of Health, Building 10, Room 7N252, Bethesda, Maryland 20892-1674, USA
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46
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Balcerczak M, Pasz-Walczak G, Balcerczak E, Wojtylak M, Kordek R, Mirowski M. HMGI(Y) gene expression in colorectal cancer: comparison with some histological typing, grading, and clinical staging. Pathol Res Pract 2004; 199:641-6. [PMID: 14666966 DOI: 10.1078/0344-0338-00475] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We investigated HMGI(Y) gene expression in 81 pairs of frozen samples obtained from colorectal carcinomas and adjacent normal colorectal mucosas and in four samples from colorectal mucosa from patients without neoplastic diseases. In this group, HMGI(Y)-positive/-negative expression was compared with some histological features, grading, and clinical staging of neoplasms investigated to assess its potential role as a prognostic marker for colorectal cancer. Expression of HMGI(Y) gene was found in 51 of 81 cases of colorectal cancers, while, in normal mucosa, expression of this gene was not observed. HMGI(Y) gene expression was associated with more advanced tumors (T3, T4) and metastases to lymph nodes (N1, N2). The most interesting finding was that expression of this gene correlated with distant metastases. HMGI(Y) gene expression was detected in all cases classified as M1 (n = 19, p = 0.0008). We did not find any association between age, gender, tumor localization, histological type and this gene expression.
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Affiliation(s)
- M Balcerczak
- Department of Pharmaceutical Biochemistry, Molecular Biology Laboratory, Lodz, Poland
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47
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Chen X, Lechago J, Ertan A, Ergun G, Verm R, Bridges M, Johnson C, Woods K, Meriano F, Chirala M, Younes M. Expression of the high mobility group proteins HMGI(Y) correlates with malignant progression in Barrett's metaplasia. Cancer Epidemiol Biomarkers Prev 2004; 13:30-3. [PMID: 14744729 DOI: 10.1158/1055-9965.epi-03-0151] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Expression of the high mobility group proteins HMGI(Y) has been shown to be a marker of malignancy in thyroid and pancreatic lesions and to correlate significantly with malignant progression in the colon. The aim of this study was to determine whether HMGI(Y) expression is associated with malignant progression in Barrett's metaplasia (BM). Immunoperoxidase staining for HMGI(Y) was performed on sections of formalin-fixed paraffin-embedded endoscopic esophageal biopsies from 42 patients with BM. These consisted of 19 biopsies negative for dysplasia (ND), 16 with low-grade dysplasia (LGD)/indeterminate for dysplasia (IND), and 7 with high-grade dysplasia (HGD)/adenocarcinoma (CA). The percentage of positive cells was recorded, and nuclear HMGI(Y) immunoreactivity in >10% of the cells was considered positive. Statistical analysis was performed using Fisher's exact test. Positive HMGI(Y) staining was detected in 2 of 19 (11%) cases ND, 5 of 16 (30%) LGD/IND cases, and 7 of 7 (100%) HGD/CA cases. Biopsies with HGD/CA were significantly more likely to be positive for HMGI(Y) than biopsies ND (P < 0.0001) or with LGD/IND (P = 0.0046). We conclude that HMGI(Y) expression is significantly associated with malignant progression in BM. Additional studies are needed to determine whether BM biopsies that are ND or LGD/IND and positive for HMGI(Y) are more likely to progress to adenocarcinoma.
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Affiliation(s)
- Xueyun Chen
- Department of Pathology, Section of Gastroenterology, Baylor College of Medicine and The Methodist Hospital, Houston, Texas, USA
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48
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Affiliation(s)
- Raymond Reeves
- School of Molecular Biosciences, Biochemistry/Biophysics, Washington State University, Pullman, Washington 99164-4660, USA
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49
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Massaad-Massade L, Tacine R, Dulauroy S, Reeves R, Barouki R. The functional interaction between HMGA1 and the estrogen receptor requires either the N- or the C-terminal domain of the receptor. FEBS Lett 2004; 559:89-95. [PMID: 14960313 DOI: 10.1016/s0014-5793(04)00032-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2003] [Revised: 01/09/2004] [Accepted: 01/09/2004] [Indexed: 11/21/2022]
Abstract
We have previously shown that HMGA1 enhances the transcriptional activity of promoters containing the estrogen response element (ERE) and increases binding of the estrogen receptor (ER) to ERE. Herein, we have assessed the transcriptional activity and ERE-binding ability of deleted ER fragments in absence or in presence of HMGA1. The HMGA1 protein stimulated binding and transcriptional activity by a factor of about 2-fold compared to the wild-type ER and both the N- and C-terminal ER deleted domains, but had no effect when both domains were deleted. These data show that HMGA1 cooperates with either the N- or the C-terminal transcriptional activation domain of the ER.
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Affiliation(s)
- Liliane Massaad-Massade
- Université René Descartes, Laboratoire de Toxicologie Moléculaire, U-490 INSERM, 45 rue des Saints-Pères, 75270 Paris Cedex, France.
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50
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O'Sullivan A, Chang HC, Yu Q, Kaplan MH. STAT4 is required for interleukin-12-induced chromatin remodeling of the CD25 locus. J Biol Chem 2003; 279:7339-45. [PMID: 14660657 DOI: 10.1074/jbc.m309979200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signal transducer and activator of transcription 4 (STAT4) is a critical mediator of interleukin-12 (IL-12)-stimulated inflammatory immune responses. Despite extensive analysis of the immune responses of STAT4-deficient mice, there is still very little understood about STAT4-dependent gene induction. IL-12 stimulated increases in IL-2 receptor alpha chain gene (CD25) mRNA levels and surface expression require STAT4. In this report, we utilize chromatin immunoprecipitation assays to analyze IL-12-stimulated and STAT4-dependent changes in chromatin remodeling of the CD25 gene. Gene activation requires binding of STAT4 to the PRRIII upstream regulatory element, the recruitment of the CREB-binding protein (CBP), and chromatin remodeling including increased acetylation and decreased methylation of histones within the CD25 promoter. Evidence suggests that STAT4 also facilitates binding of other factors to the CD25 promoter including c-Jun. Thus, these results provide a model for STAT4-dependent gene induction and a mechanism for cytokine-induced expression of the CD25 gene.
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Affiliation(s)
- Audrey O'Sullivan
- Department of Microbiology and Immunology and the Walther Oncology Center, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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