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Ren Q, Liu Z, Wu L, Yin G, Xie X, Kong W, Zhou J, Liu S. C/EBPβ: The structure, regulation, and its roles in inflammation-related diseases. Biomed Pharmacother 2023; 169:115938. [PMID: 38000353 DOI: 10.1016/j.biopha.2023.115938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 11/08/2023] [Accepted: 11/21/2023] [Indexed: 11/26/2023] Open
Abstract
Inflammation, a mechanism of the human body, has been implicated in many diseases. Inflammatory responses include the release of inflammatory mediators by activating various signaling pathways. CCAAT/enhancer binding protein β (C/EBPβ), a transcription factor in the C/EBP family, contains the leucine zipper (bZIP) domain. The expression of C/EBPβ is mediated at the transcriptional and post-translational levels, such as phosphorylation, acetylation, methylation, and SUMOylation. C/EBPβ has been involved in inflammatory responses by mediating several signaling pathways, such as MAPK/NF-κB and IL-6/JAK/STAT3 pathways. C/EBPβ plays an important role in the pathological development of inflammation-related diseases, such as osteoarthritis, pneumonia, hepatitis, inflammatory bowel diseases, and rheumatoid arthritis. Here, we comprehensively discuss the structure and biological effects of C/EBPβ and its role in inflammatory diseases.
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Affiliation(s)
- Qun Ren
- Department of Pharmacy, Gannan Medical University, Ganzhou 341000, China
| | - Zhaowen Liu
- Department of Pharmacy, Gannan Medical University, Ganzhou 341000, China
| | - Longhuo Wu
- Department of Pharmacy, Gannan Medical University, Ganzhou 341000, China
| | - Guoqiang Yin
- Ganzhou People's Hospital Affiliated to Nanchang University, Ganzhou 341000, China
| | - Xunlu Xie
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Weihao Kong
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Jianguo Zhou
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Shiwei Liu
- Department of Joint Surgery, Ganzhou People's Hospital, Ganzhou 341000, China.
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2
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Luo Y, Ge P, Wen H, Zhang Y, Liu J, Dong X, Lan B, Zhang G, Yang Q, Chen H. C/EBPβ Promotes LPS-Induced IL-1β Transcription and Secretion in Alveolar Macrophages via NOD2 Signaling. J Inflamm Res 2022; 15:5247-5263. [PMID: 36120185 PMCID: PMC9477153 DOI: 10.2147/jir.s377499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/01/2022] [Indexed: 12/11/2022] Open
Abstract
Objective C/EBPβ, a crucial transcription factor, regulates innate immunity and inflammatory responses. However, the role played by C/EBPβ in alveolar macrophage (AM) inflammatory responses remains unknown. This study aimed to investigate the role and mechanism of C/EBPβ in alveolar macrophages (AMs) from the transcriptional level and to search for natural compounds targeting C/EBPβ. Methods Rat AMs were infected with Lv-sh-C/EBPβ and treated with LPS, and the expression levels of iNOS, TNF-α, IL-6, and IL-1β were measured by RT-qPCR, Western blotting, and ELISA. Mechanistically, transcriptome sequencing (RNA-seq) revealed changes in gene expression patterns in AMs after LPS stimulation and C/EBPβ knockdown. Functional enrichment analyses and rescue experiments identified and validated inflammation-associated cell signaling pathways regulated by C/EBPβ. Furthermore, virtual screening was used to search for natural compounds that inhibit C/EBPβ with the structure of helenalin as a reference. Results Following stimulation with LPS, AMs exhibited an increased expression of C/EBPβ. C/EBPβ knockdown significantly decreased the expression levels of inflammatory mediators. A total of 374 differentially expressed genes (DEGs) were identified between LPS-stimulated C/EBPβ knockdown and negative control cells. The NOD-like receptor signaling may be a key target for C/EBPβ, according to functional enrichment analyses of the DEGs. Further experiments showed that the muramyl dipeptide (MDP, NOD2 agonist) reversed the downregulation of inflammatory mediators and the NF-κB pathway caused by the C/EBPβ knockdown. The virtual screening revealed that N-caffeoyltryptophan, orilotimod, and petasiphenone have comparable pharmacological properties to helenalin (a known C/EBPβ inhibitor) and demonstrate a great binding capacity to C/EBPβ. Conclusion Ablation of C/EBPβ may attenuate LPS-induced inflammatory damage in AMs by inhibiting the NOD2 receptor signaling pathway. Three natural compounds, N-caffeoyltryptophan, orilotimod, and petasiphenone, may be potential C/EBPβ inhibitors.
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Affiliation(s)
- Yalan Luo
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Peng Ge
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Haiyun Wen
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Yibo Zhang
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Jin Liu
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Xuanchi Dong
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Bowen Lan
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Guixin Zhang
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Qi Yang
- Department of Traditional Chinese Medicine, The Second Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Hailong Chen
- Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.,Institute (College) of Integrative Medicine, Dalian Medical University, Dalian, People's Republic of China.,Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
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3
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Wang L, Wang P, Xu S, Li Z, Duan DD, Ye J, Li J, Ding Y, Zhang W, Lu J, Liu P. The cross-talk between PARylation and SUMOylation in C/EBPβ at K134 site participates in pathological cardiac hypertrophy. Int J Biol Sci 2022; 18:783-799. [PMID: 35002525 PMCID: PMC8741850 DOI: 10.7150/ijbs.65211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 11/13/2021] [Indexed: 12/23/2022] Open
Abstract
Poly(ADP-ribosyl)ation (PARylation) and SUMO modification (SUMOylation) are novel post-translational modifications (PTMs) mainly induced by PARP1 and SUMO1. Growing evidence has revealed that C/EBPβ plays multiple roles in biological processes and participates in cardiovascular diseases. However, the cross-talk between C/EBPβ PARylation and SUMOylation during cardiovascular diseases is unknown. This study aims to investigate the effects of C/EBPβ PTMs on cardiac hypertrophy and its underlying mechanism. Abdominal aortic constriction (AAC) and phenylephrine (PE) were conducted to induce cardiac hypertrophy. Intramyocardial delivery of recombinant adenovirus (Ad-PARP1) was taken to induce PARP1 overexpression. In this study, we found C/EBPβ participates in PARP1-induced cardiac hypertrophy. C/EBPβ K134 residue could be both PARylated and SUMOylated individually by PARP1 and SUMO1. Moreover, the accumulation of PARylation on C/EBPβ at K134 site exhibits downregulation of C/EBPβ SUMOylation at the same site. Importantly, C/EBPβ K134 site SUMOylation could decrease C/EBPβ protein stability and participates in PARP1-induced cardiac hypertrophy. Taken together, these findings highlight the importance of the cross-talk between C/EBPβ PTMs at K134 site in determining its protein level and function, suggesting that multi-target pharmacological strategies inhibiting PARP1 and activating C/EBPβ SUMOylation would be potential for treating pathological cardiac hypertrophy.
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Affiliation(s)
- Luping Wang
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China.,Laboratory of Hematopathology & Drug Discovery, School of Medicine, South China University of Technology, Guangdong, China
| | - Panxia Wang
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Suowen Xu
- Department of Endocrinology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Anhui, China
| | - Zhuoming Li
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Dayue Darrel Duan
- Center for Phenomics of Traditional Chinese Medicine/the Affiliated Hospital of Traditional Chinese Medicine, Southwest Medical University, Sichuan, China
| | - Jiantao Ye
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Jingyan Li
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Yanqing Ding
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Wenqing Zhang
- Laboratory of Hematopathology & Drug Discovery, School of Medicine, South China University of Technology, Guangdong, China
| | - Jing Lu
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China
| | - Peiqing Liu
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China.,National and Local United Engineering Lab of Druggability and New Drugs Evaluation, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangdong, China.,School of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangdong, China
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4
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Xiao Y, Qureischi M, Dietz L, Vaeth M, Vallabhapurapu SD, Klein-Hessling S, Klein M, Liang C, König A, Serfling E, Mottok A, Bopp T, Rosenwald A, Buttmann M, Berberich I, Beilhack A, Berberich-Siebelt F. Lack of NFATc1 SUMOylation prevents autoimmunity and alloreactivity. J Exp Med 2021; 218:152124. [PMID: 32986812 PMCID: PMC7953626 DOI: 10.1084/jem.20181853] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 04/22/2020] [Accepted: 07/17/2020] [Indexed: 12/16/2022] Open
Abstract
Posttranslational modification with SUMO is known to regulate the activity of transcription factors, but how SUMOylation of individual proteins might influence immunity is largely unexplored. The NFAT transcription factors play an essential role in antigen receptor-mediated gene regulation. SUMOylation of NFATc1 represses IL-2 in vitro, but its role in T cell-mediated immune responses in vivo is unclear. To this end, we generated a novel transgenic mouse in which SUMO modification of NFATc1 is prevented. Avoidance of NFATc1 SUMOylation ameliorated experimental autoimmune encephalomyelitis as well as graft-versus-host disease. Elevated IL-2 production in T cells promoted T reg expansion and suppressed autoreactive or alloreactive immune responses. Mechanistically, increased IL-2 secretion counteracted IL-17 and IFN-γ expression through STAT5 and Blimp-1 induction. Then, Blimp-1 repressed IL-2 itself, as well as the induced, proliferation-associated survival factor Bcl2A1. Collectively, these data demonstrate that prevention of NFATc1 SUMOylation fine-tunes T cell responses toward lasting tolerance. Thus, targeting NFATc1 SUMOylation presents a novel and promising strategy to treat T cell-mediated inflammatory diseases.
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Affiliation(s)
- Yin Xiao
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Musga Qureischi
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany.,Department of Medicine II, Center for Interdisciplinary Clinical Research, University Hospital Wuerzburg, Wuerzburg, Germany.,Graduate School of Life Sciences, University of Wuerzburg, Wuerzburg, Germany
| | - Lena Dietz
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Martin Vaeth
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | | | - Stefan Klein-Hessling
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany.,Department of Molecular Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Matthias Klein
- Institute for Immunology, University Medical Center, University of Mainz, Mainz, Germany
| | - Chunguang Liang
- Functional Genomics and Systems Biology Group, Department of Bioinformatics, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Anika König
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Edgar Serfling
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany.,Department of Molecular Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Anja Mottok
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Tobias Bopp
- Institute for Immunology, University Medical Center, University of Mainz, Mainz, Germany.,Research Center for Immunotherapy, University Medical Center, University of Mainz, Mainz, Germany.,University Cancer Center Mainz, University Medical Center, University of Mainz, Mainz, Germany.,German Cancer Consortium, University Medical Center, University of Mainz, Mainz, Germany
| | - Andreas Rosenwald
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany.,Comprehensive Cancer Centre Mainfranken, University of Wuerzburg, Wuerzburg, Germany
| | - Mathias Buttmann
- Department of Neurology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Ingolf Berberich
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Andreas Beilhack
- Department of Medicine II, Center for Interdisciplinary Clinical Research, University Hospital Wuerzburg, Wuerzburg, Germany
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5
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Joshi H, Lunz B, Peters A, Zölch M, Berberich I, Berberich-Siebelt F. The extreme C-terminus of IRAK2 assures full TRAF6 ubiquitination and optimal TLR signaling. Mol Immunol 2021; 134:172-182. [PMID: 33799071 DOI: 10.1016/j.molimm.2021.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 02/15/2021] [Accepted: 03/18/2021] [Indexed: 01/10/2023]
Abstract
Macrophages are fundamental for initiation, maintenance, and resolution of inflammation. They can be activated by 'Toll-like receptor' (TLR) engagement, which initiates critical pathways to fight infections. 'Interleukin receptor-associated kinase 2' (IRAK2) is part of the membrane-proximal Myddosome formed at IL-1R/TLRs, but utility and regulation of IRAK2 within is not completely understood. In this study, we addressed the importance of the evolutionary conserved extreme C-terminus of IRAK2 in TLR signaling. The last 55 amino acids lack any known functional domain. The C-terminus deletion mutant IRAK2Δ55 was hypofunctional and disabled to conduct TLR4-inducible NF-κB and ERK2 activation. Accordingly, it could neither fully support subsequent CD40 cell surface expression nor IL-6 and nitric oxide release. Interestingly, IRAK2Δ55 was still capable to bind to 'tumor necrosis factor receptor-associated factor 6' (TRAF6), which is requisite to activate TRAF6 as an E3-ubiquitin ligase for further downstream signaling. However, IRAK-dependent auto-ubiquitination of TRAF6 was impaired, when IRAK2Δ55 was bound. Thus, the conserved last 55 amino acids enable IRAK2 to sustain an optimal TLR response. This knowledge might spark ideas how overshooting inflammatory responses could be modified without blocking the entire immune response.
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Affiliation(s)
- Hemant Joshi
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Benjamin Lunz
- Institute of Pathology, University of Wuerzburg, Wuerzburg, Germany
| | - Andrea Peters
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Michael Zölch
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Ingolf Berberich
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
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Piazzi M, Bavelloni A, Faenza I, Blalock W. Glycogen synthase kinase (GSK)-3 and the double-strand RNA-dependent kinase, PKR: When two kinases for the common good turn bad. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118769. [PMID: 32512016 PMCID: PMC7273171 DOI: 10.1016/j.bbamcr.2020.118769] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 01/08/2023]
Abstract
Glycogen synthase kinase (GSK)-3α/β and the double-stranded RNA-dependent kinase PKR are two sentinel kinases that carry-out multiple similar yet distinct functions in both the cytosol and the nucleus. While these kinases belong to separate signal transduction cascades, they demonstrate an uncanny propensity to regulate many of the same proteins either through direct phosphorylation or by altering transcription/translation, including: c-MYC, NF-κB, p53 and TAU, as well as each another. A significant number of studies centered on the GSK3 kinases have led to the identification of the GSK3 interactome and a number of substrates, which link GSK3 activity to metabolic control, translation, RNA splicing, ribosome biogenesis, cellular division, DNA repair and stress/inflammatory signaling. Interestingly, many of these same pathways and processes are controlled by PKR, but unlike the GSK3 kinases, a clear picture of proteins interacting with PKR and a complete listing of its substrates is still missing. In this review, we take a detailed look at what is known about the PKR and GSK3 kinases, how these kinases interact to influence common cellular processes (innate immunity, alternative splicing, translation, glucose metabolism) and how aberrant activation of these kinases leads to diseases such as Alzheimer's disease (AD), diabetes mellitus (DM) and cancer. GSK3α/β and PKR are major regulators of cellular homeostasis and the response to stress/inflammation and infection. GSK3α/β and PKR interact with and/or modify many of the same proteins and affect the expression of similar genes. A balance between AKT and PKR nuclear signaling may be responsible for regulating the activation of nuclear GSK3β. GSK3α/β- and PKR-dependent signaling influence major molecular mechanisms of the cell through similar intermediates. Aberrant activation of GSK3α/β and PKR is highly involved in cancer, metabolic disorders, and neurodegenerative diseases.
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Affiliation(s)
- Manuela Piazzi
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza", Consiglio Nazionale delle Ricerche (IGM-CNR), Bologna, Italy; IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Alberto Bavelloni
- Laboratoria di Oncologia Sperimentale, IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Irene Faenza
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - William Blalock
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza", Consiglio Nazionale delle Ricerche (IGM-CNR), Bologna, Italy; IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy.
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7
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Spike AJ, Rosen JM. C/EBPß Isoform Specific Gene Regulation: It's a Lot more Complicated than you Think! J Mammary Gland Biol Neoplasia 2020; 25:1-12. [PMID: 32078094 PMCID: PMC7694698 DOI: 10.1007/s10911-020-09444-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/06/2020] [Indexed: 11/29/2022] Open
Abstract
It has been almost 30 years since C/EBPß was discovered. Seminal studies have shown that C/EBPß is a master regulator of mammary gland development and has been shown to control and influence proliferation and differentiation through varying mechanisms. The single-exon C/EBPß mRNA yields at least three different protein isoforms which have diverse, specific, context-dependent, and often non-overlapping roles throughout development and breast cancer progression. These roles are dictated by a number of complex factors including: expression levels of other C/EBP family members and their stoichiometry relative to the isoform in question, binding site affinity, post-translational modifications, co-factor expression, and even hormone levels and lactogenic status. Here we summarize the historical work up to the latest findings in the field on C/EBPß in the mammary gland and in breast cancer. With the current emphasis on improving immunotherapy in breast cancer the role of specific C/EBPß isoforms in regulating specific chemokine and cytokine expression and the immune microenvironment will be of increasing interest.
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Affiliation(s)
- Aaron J Spike
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Jeffrey M Rosen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA.
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8
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Cappelletti M, Presicce P, Lawson MJ, Chaturvedi V, Stankiewicz TE, Vanoni S, Harley IT, McAlees JW, Giles DA, Moreno-Fernandez ME, Rueda CM, Senthamaraikannan P, Sun X, Karns R, Hoebe K, Janssen EM, Karp CL, Hildeman DA, Hogan SP, Kallapur SG, Chougnet CA, Way SS, Divanovic S. Type I interferons regulate susceptibility to inflammation-induced preterm birth. JCI Insight 2017; 2:e91288. [PMID: 28289719 DOI: 10.1172/jci.insight.91288] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Preterm birth (PTB) is a leading worldwide cause of morbidity and mortality in infants. Maternal inflammation induced by microbial infection is a critical predisposing factor for PTB. However, biological processes associated with competency of pathogens, including viruses, to induce PTB or sensitize for secondary bacterial infection-driven PTB are unknown. We show that pathogen/pathogen-associated molecular pattern-driven activation of type I IFN/IFN receptor (IFNAR) was sufficient to prime for systemic and uterine proinflammatory chemokine and cytokine production and induction of PTB. Similarly, treatment with recombinant type I IFNs recapitulated such effects by exacerbating proinflammatory cytokine production and reducing the dose of secondary inflammatory challenge required for induction of PTB. Inflammatory challenge-driven induction of PTB was eliminated by defects in type I IFN, TLR, or IL-6 responsiveness, whereas the sequence of type I IFN sensing by IFNAR on hematopoietic cells was essential for regulation of proinflammatory cytokine production. Importantly, we also show that type I IFN priming effects are conserved from mice to nonhuman primates and humans, and expression of both type I IFNs and proinflammatory cytokines is upregulated in human PTB. Thus, activation of the type I IFN/IFNAR axis in pregnancy primes for inflammation-driven PTB and provides an actionable biomarker and therapeutic target for mitigating PTB risk.
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Affiliation(s)
| | - Pietro Presicce
- Division of Neonatology/Pulmonary Biology, Cincinnati Children's Hospital Research Foundation
| | - Matthew J Lawson
- Division of Immunobiology.,Molecular, Cellular and Biochemical Pharmacology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | | | - Simone Vanoni
- Division of Allergy and Immunology, Cincinnati Children's Hospital Research Foundation, and the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | | | - Daniel A Giles
- Division of Immunobiology.,Immunology Graduate Program, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | | | | | | | - Rebekah Karns
- Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Research Foundation, and the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | | | | | | | | | - Simon P Hogan
- Division of Allergy and Immunology, Cincinnati Children's Hospital Research Foundation, and the University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Suhas G Kallapur
- Division of Neonatology/Pulmonary Biology, Cincinnati Children's Hospital Research Foundation
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9
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Ding S, Gan T, Song M, Dai Q, Huang H, Xu Y, Zhong C. C/EBPB-CITED4 in Exercised Heart. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1000:247-259. [PMID: 29098625 DOI: 10.1007/978-981-10-4304-8_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
C/EBPB is a crucial transcription factor, participating in a variety of biological processes including cell proliferation, differentiation and development. In the cardiovascular system, C/EBPB-CITED4 signaling is known as a signaling pathway mediating exercise-induced cardiac growth. After its exact role in exercised heart firstly reported in 2010, more and more evidence confirmed that. MicroRNA (e.g. miR-222) and many molecules (e.g. Alpha-lipoic acid) can regulate this pathway and then involve in the cardiac protection effect induced by endurance exercise training. In addition, in cardiac growth during pregnancy, C/EBPB is also a required regulator. This chapter will give an introduction of the C/EBPB-CITED4 signaling and the regulatory network based on this signaling pathway in exercised heart.
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Affiliation(s)
- Shengguang Ding
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Tianyi Gan
- State Key Laboratory of Cardiovascular Disease, Heart Failure Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China
| | - Meiyi Song
- Division of Gastroenterology and Hepatology, Digestive Disease Institute, Shanghai Tongji Hospital, Tongji University School of Medicine, 389 Xin Cun Road, Shanghai, 200065, China
| | - Qiying Dai
- Metrowest Medical Center, Framingham, 01702, MA, USA.,Department of Cardiology, First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Haitao Huang
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Yiming Xu
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Chongjun Zhong
- Department of Thoracic and Cardiovascular Surgery, The Second Affiliated Hospital of Nantong University, Nantong, 226001, China.
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10
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Martinez-Castillo M, Bonilla-Moreno R, Aleman-Lazarini L, Meraz-Rios MA, Orozco L, Cedillo-Barron L, Cordova EJ, Villegas-Sepulveda N. A Subpopulation of the K562 Cells Are Killed by Curcumin Treatment after G2/M Arrest and Mitotic Catastrophe. PLoS One 2016; 11:e0165971. [PMID: 27832139 PMCID: PMC5104431 DOI: 10.1371/journal.pone.0165971] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 10/20/2016] [Indexed: 01/29/2023] Open
Abstract
Curcumin is extensively investigated as a good chemo-preventive agent in the development of many cancers and particularly in leukemia, including treatment of chronic myelogenous leukemia and it has been proposed as an adjuvant for leukemia therapies. Human chronic myeloid leukemia cells (K562), were treated with 20 μM of curcumin, and we found that a subpopulation of these cells were arrested and accumulate in the G2/M phase of the cell cycle. Characterization of this cell subpopulation showed that the arrested cells presented nuclear morphology changes resembling those described for mitotic catastrophe. Mitotic cells displayed abnormal chromatin organization, collapse of the mitotic spindle and abnormal chromosome segregation. Then, these cells died in an apoptosis dependent manner and showed diminution in the protein levels of BCL-2 and XIAP. Moreover, our results shown that a transient activation of the nuclear factor κB (NFκB) occurred early in these cells, but decreased after 6 h of the treatment, explaining in part the diminution of the anti-apoptotic proteins. Additionally, P73 was translocated to the cell nuclei, because the expression of the C/EBPα, a cognate repressor of the P73 gene, was decreased, suggesting that apoptosis is trigger by elevation of P73 protein levels acting in concert with the diminution of the two anti-apoptotic molecules. In summary, curcumin treatment might produce a P73-dependent apoptotic cell death in chronic myelogenous leukemia cells (K562), which was triggered by mitotic catastrophe, due to sustained BAX and survivin expression and impairment of the anti-apoptotic proteins BCL-2 and XIAP.
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Affiliation(s)
- Macario Martinez-Castillo
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
| | - Raul Bonilla-Moreno
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
| | - Leticia Aleman-Lazarini
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
| | - Marco Antonio Meraz-Rios
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
| | - Lorena Orozco
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, Instituto Nacional de Medicina Genómica, Secretaria de Salud, Mexico City, México
| | - Leticia Cedillo-Barron
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
| | - Emilio J. Cordova
- Laboratorio de Inmunogenómica y Enfermedades Metabólicas, Instituto Nacional de Medicina Genómica, Secretaria de Salud, Mexico City, México
| | - Nicolas Villegas-Sepulveda
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados, Mexico City, Mexico
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11
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In K, Zaini MA, Müller C, Warren AJ, von Lindern M, Calkhoven CF. Shwachman-Bodian-Diamond syndrome (SBDS) protein deficiency impairs translation re-initiation from C/EBPα and C/EBPβ mRNAs. Nucleic Acids Res 2016; 44:4134-46. [PMID: 26762974 PMCID: PMC4872075 DOI: 10.1093/nar/gkw005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/31/2015] [Indexed: 01/24/2023] Open
Abstract
Mutations in the Shwachman–Bodian–Diamond Syndrome (SBDS) gene cause Shwachman–Diamond Syndrome (SDS), a rare congenital disease characterized by bone marrow failure with neutropenia, exocrine pancreatic dysfunction and skeletal abnormalities. The SBDS protein is important for ribosome maturation and therefore SDS belongs to the ribosomopathies. It is unknown, however, if loss of SBDS functionality affects the translation of specific mRNAs and whether this could play a role in the development of the clinical features of SDS. Here, we report that translation of the C/EBPα and -β mRNAs, that are indispensible regulators of granulocytic differentiation, is altered by SBDS mutations or knockdown. We show that SBDS function is specifically required for efficient translation re-initiation into the protein isoforms C/EBPα-p30 and C/EBPβ-LIP, which is controlled by a single cis-regulatory upstream open reading frame (uORF) in the 5′ untranslated regions (5′ UTRs) of both mRNAs. Furthermore, we show that as a consequence of the C/EBPα and -β deregulation the expression of MYC is decreased with associated reduction in proliferation, suggesting that failure of progenitor proliferation contributes to the haematological phenotype of SDS. Therefore, our study provides the first indication that disturbance of specific translation by loss of SBDS function may contribute to the development of the SDS phenotype.
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Affiliation(s)
- Kyungmin In
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany
| | - Mohamad A Zaini
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany European Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD, Groningen, The Netherlands
| | - Christine Müller
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany European Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD, Groningen, The Netherlands
| | - Alan J Warren
- Cambridge Institute for Medical Research, Wellcome Trust-Medical Research Council Stem Cell Institute, the Department of Haematology, University of Cambridge, CB2 0XY, Cambridge, UK
| | - Marieke von Lindern
- Sanquin Research and Landsteiner Laboratory, Department of Hematopoiesis, 1066 CX Amsterdam, The Netherlands
| | - Cornelis F Calkhoven
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstrasse 11, D-07745 Jena, Germany European Institute for the Biology of Ageing (ERIBA), University Medical Center Groningen, University of Groningen, 9700 AD, Groningen, The Netherlands
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12
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Pulido-Salgado M, Vidal-Taboada JM, Saura J. C/EBPβ and C/EBPδ transcription factors: Basic biology and roles in the CNS. Prog Neurobiol 2015; 132:1-33. [PMID: 26143335 DOI: 10.1016/j.pneurobio.2015.06.003] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 05/08/2015] [Accepted: 06/16/2015] [Indexed: 02/01/2023]
Abstract
CCAAT/enhancer binding protein (C/EBP) β and C/EBPδ are transcription factors of the basic-leucine zipper class which share phylogenetic, structural and functional features. In this review we first describe in depth their basic molecular biology which includes fascinating aspects such as the regulated use of alternative initiation codons in the C/EBPβ mRNA. The physical interactions with multiple transcription factors which greatly opens the number of potentially regulated genes or the presence of at least five different types of post-translational modifications are also remarkable molecular mechanisms that modulate C/EBPβ and C/EBPδ function. In the second part, we review the present knowledge on the localization, expression changes and physiological roles of C/EBPβ and C/EBPδ in neurons, astrocytes and microglia. We conclude that C/EBPβ and C/EBPδ share two unique features related to their role in the CNS: whereas in neurons they participate in memory formation and synaptic plasticity, in glial cells they regulate the pro-inflammatory program. Because of their role in neuroinflammation, C/EBPβ and C/EBPδ in microglia are potential targets for treatment of neurodegenerative disorders. Any strategy to reduce C/EBPβ and C/EBPδ activity in neuroinflammation needs to take into account its potential side-effects in neurons. Therefore, cell-specific treatments will be required for the successful application of this strategy.
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Affiliation(s)
- Marta Pulido-Salgado
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Jose M Vidal-Taboada
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain
| | - Josep Saura
- Biochemistry and Molecular Biology Unit, School of Medicine, University of Barcelona, IDIBAPS, Casanova 143, planta 3, 08036 Barcelona, Spain.
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13
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Guo L, Li X, Tang QQ. Transcriptional regulation of adipocyte differentiation: a central role for CCAAT/enhancer-binding protein (C/EBP) β. J Biol Chem 2014; 290:755-61. [PMID: 25451943 DOI: 10.1074/jbc.r114.619957] [Citation(s) in RCA: 224] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A detailed understanding of the processes controlling adipogenesis is instrumental in the fight against the obesity epidemic. Adipogenesis is controlled by a transcriptional cascade composed of a large number of transcriptional factors, among which CCAAT/enhancer-binding protein (C/EBP) β plays an essential role. During 3T3-L1 adipocyte differentiation, C/EBPβ is induced early to transactivate the expression of C/EBPα and peroxisome proliferator-activated receptor γ (PPARγ), two master transcription factors for terminal adipocyte differentiation. Studies in recent years have revealed many new target genes of C/EBPβ, implicating its participation in many other processes during adipogenesis, such as mitotic clonal expansion, epigenetic regulation, unfolded protein response, and autophagy. Moreover, the function of C/EBPβ is highly regulated by post-translational modifications, which are crucial for the proper activation of the adipogenic program. Advances toward elucidation of the function and roles of the post-translational modification of C/EBPβ during adipogenesis will greatly improve our understanding of the molecular mechanisms governing adipogenesis.
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Affiliation(s)
- Liang Guo
- From the Key Laboratory of Metabolism and Molecular Medicine, the Ministry of Education and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, China
| | - Xi Li
- From the Key Laboratory of Metabolism and Molecular Medicine, the Ministry of Education and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, China
| | - Qi-Qun Tang
- From the Key Laboratory of Metabolism and Molecular Medicine, the Ministry of Education and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, China
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14
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Leidner J, Voogdt C, Niedenthal R, Möller P, Marienfeld U, Marienfeld RB. SUMOylation Attenuates the Transcriptional Activity of the NF-κB Subunit RelB. J Cell Biochem 2014; 115:1430-40. [DOI: 10.1002/jcb.24794] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 02/20/2014] [Indexed: 12/22/2022]
Affiliation(s)
- Julia Leidner
- Institute of Physiological Chemistry; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Cornelia Voogdt
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Rainer Niedenthal
- Institute for Physiological Chemistry/Biochemistry; Hannover Medical School; Carl-Neuberg Strasse 1 30625 Hannover Germany
| | - Peter Möller
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Uta Marienfeld
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
| | - Ralf B. Marienfeld
- Institute of Pathology; University of Ulm; Albert-Einstein-Allee 23 89070 Ulm Germany
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15
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Cassone CG, Taylor JJ, O'Brien JM, Williams A, Yauk CL, Crump D, Kennedy SW. Transcriptional profiles in the cerebral hemisphere of chicken embryos following in ovo perfluorohexane sulfonate exposure. Toxicol Sci 2012; 129:380-91. [PMID: 22790973 DOI: 10.1093/toxsci/kfs219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In a recent egg injection study, we showed that in ovo exposure to perfluorohexane sulfonate (PFHxS) affects the pipping success of developing chicken (Gallus gallus domesticus) embryos. We also found evidence of thyroid hormone (TH) pathway interference at multiple levels of biological organization (i.e., somatic growth, messenger RNA expression, and circulating free thyroxine levels). Based on these findings, we hypothesize that PFHxS exposure interferes with TH-dependent neurodevelopmental pathways. This study investigates global transcriptional profiles in cerebral hemispheres of chicken embryos following exposure to a solvent control, 890 or 38,000 ng PFHxS/g egg (n = 4-5 per group); doses that lead to the adverse effects indicated above. PFHxS significantly alters the expression (≥ 1.5-fold, p ≤ 0.001) of 11 transcripts at the low dose (890 ng/g) and 101 transcripts at the high dose (38,000 ng/g). Functional enrichment analysis shows that PFHxS affects genes involved in tissue development and morphology, cellular assembly and organization, and cell-to-cell signaling. Pathway and interactome analyses suggest that genes may be affected through several potential regulatory molecules, including integrin receptors, myelocytomatosis viral oncogene, and CCAAT/enhancer-binding protein. This study identifies key functional and regulatory modes of PFHxS action involving TH-dependent and -independent neurodevelopmental pathways. Some of these TH-dependent mechanisms that occur during embryonic development include tight junction formation, signal transduction, and integrin signaling, whereas TH-independent mechanisms include gap junction intercellular communication.
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Affiliation(s)
- Cristina G Cassone
- Environment Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada K1A 0H3
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16
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Leutz A, Pless O, Lappe M, Dittmar G, Kowenz-Leutz E. Crosstalk between phosphorylation and multi-site arginine/lysine methylation in C/EBPs. Transcription 2012; 2:3-8. [PMID: 21326902 DOI: 10.4161/trns.2.1.13510] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/01/2010] [Accepted: 09/01/2010] [Indexed: 12/24/2022] Open
Abstract
C/EBPs are implied in an amazing number of cellular functions: C/EBPs regulate tissue and cell type specific gene expression, proliferation, and differentiation control. C/EBPs assist in energy metabolism, female reproduction, innate immunity, inflammation, senescence, and the development of neoplasms. How can C/EBPs fulfill so many functions? Here we discuss that C/EBPs are extensively modified by methylation of arginine and lysine side chains and that regulated methylation profoundly affects the activity of C/EBPs.
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Affiliation(s)
- Achim Leutz
- Max Delbrueck Center for Molecular Medicine, Berlin, Germany.
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17
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Ye S, Xu H, Jin J, Yang M, Wang C, Yu Y, Cao X. The E3 ubiquitin ligase neuregulin receptor degradation protein 1 (Nrdp1) promotes M2 macrophage polarization by ubiquitinating and activating transcription factor CCAAT/enhancer-binding Protein β (C/EBPβ). J Biol Chem 2012; 287:26740-8. [PMID: 22707723 DOI: 10.1074/jbc.m112.383265] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Macrophage activation, including classical (M1) activation and alternative (M2) activation, plays important roles in host immune response and pathogenesis of diseases. Ubiquitination has been shown to be involved in the differentiation of immune cells and in the regulation of immune responses. However, the role of ubiquitination during M1 versus M2 polarization is poorly explored. Here, we showed that arginase 1 (Arg1), a well recognized marker of M2 macrophages, is highly up-regulated in peritoneal macrophages derived from E3 ubiquitin ligase Nrdp1 transgenic (Nrdp1-TG) mice. Furthermore, other M2 feature markers such as MR, Ym1, and Fizz1, as well as Th2 cytokine IL-10, are also up-regulated in Nrdp1-TG macrophages after IL-4 stimulation. Knockdown of Nrdp1 expression effectively inhibits IL-4-induced expression of M2-related genes in macrophages. Moreover, Nrdp1 inhibits LPS-induced production of inducible NOS and pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in macrophages. Immunoprecipitation assays show that Nrdp1 interacts with and ubiquitinates transcriptional factor C/EBPβ via Lys-63-linked ubiquitination. Nrdp1 enhances C/EBPβ-triggered transcriptional activation of the Arg1 reporter gene in the presence of IL-4 stimulation. Thus, we demonstrate that Nrdp1-mediated ubiquitination and activation of C/EBPβ contributes to a ubiquitin-dependent nonproteolytic pathway that up-regulates Arg1 expression and promotes M2 macrophage polarization.
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Affiliation(s)
- Shuo Ye
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou 310058, China
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18
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Abstract
Glucocorticoids (GCs) have been successfully used in the treatment of inflammatory diseases for decades. However, there is a relative GC resistance in several inflammatory lung disorders, such as chronic obstructive pulmonary disease (COPD), but still the mechanism(s) behind this unresponsiveness remains unknown. Interaction between transcription factors and the GC receptor contribute to GC effects but may also provide mechanisms explaining steroid resistance. CCAAT/enhancer-binding protein (C/EBP) transcription factors are important regulators of pulmonary gene expression and have been implicated in inflammatory lung diseases such as asthma, pulmonary fibrosis, cystic fibrosis, sarcoidosis, and COPD. In addition, several studies have indicated a role for C/EBPs in mediating GC effects. In this review, we discuss the different mechanisms of GC action as well as the function of the lung-enriched members of the C/EBP transcription factor family. We also summarize the current knowledge of the role of C/EBP transcription factors in mediating the effects of GCs, with emphasis on pulmonary effects, and their potential role in mediating GC resistance.
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Affiliation(s)
- Abraham B Roos
- Respiratory Medicine Unit, Lung Research Laboratory L4:01, Department of Medicine, Karolinska Institutet, Karolinska University Hospital - Solna, 171 76 Stockholm, Sweden.
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19
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Gutsch R, Kandemir JD, Pietsch D, Cappello C, Meyer J, Simanowski K, Huber R, Brand K. CCAAT/enhancer-binding protein beta inhibits proliferation in monocytic cells by affecting the retinoblastoma protein/E2F/cyclin E pathway but is not directly required for macrophage morphology. J Biol Chem 2011; 286:22716-29. [PMID: 21558273 PMCID: PMC3123039 DOI: 10.1074/jbc.m110.152538] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Monocytic differentiation is orchestrated by complex networks that are not fully understood. This study further elucidates the involvement of transcription factor CCAAT/enhancer-binding protein β (C/EBPβ). Initially, we demonstrated a marked increase in nuclear C/EBPβ-liver-enriched activating protein* (LAP*)/liver-enriched activating protein (LAP) levels and LAP/liver-enriched inhibiting protein (LIP) ratios in phorbol 12-myristate 13-acetate (PMA)-treated differentiating THP-1 premonocytic cells accompanied by reduced proliferation. To directly study C/EBPβ effects on monocytic cells, we generated novel THP-1-derived (low endogenous C/EBPβ) cell lines stably overexpressing C/EBPβ isoforms. Most importantly, cells predominantly overexpressing LAP* (C/EBPβ-long), but not those overexpressing LIP (C/EBPβ-short), exhibited a reduced proliferation, with no effect on morphology. PMA-induced inhibition of proliferation was attenuated in C/EBPβ-short cells. In C/EBPβWT macrophage-like cells (high endogenous C/EBPβ), we measured a reduced proliferation/cycling index compared with C/EBPβKO. The typical macrophage morphology was only observed in C/EBPβWT, whereas C/EBPβKO stayed round. C/EBPα did not compensate for C/EBPβ effects on proliferation/morphology. Serum reduction, an independent approach known to inhibit proliferation, induced macrophage morphology in C/EBPβKO macrophage-like cells but not THP-1. In PMA-treated THP-1 and C/EBPβ-long cells, a reduced phosphorylation of cell cycle repressor retinoblastoma was found. In addition, C/EBPβ-long cells showed reduced c-Myc expression accompanied by increased CDK inhibitor p27 and reduced cyclin D1 levels. Finally, C/EBPβ-long and C/EBPβWT cells exhibited low E2F1 and cyclin E levels, and C/EBPβ overexpression was found to inhibit cyclin E1 promoter-dependent transcription. Our results suggest that C/EBPβ reduces monocytic proliferation by affecting the retinoblastoma/E2F/cyclin E pathway and that it may contribute to, but is not directly required for, macrophage morphology. Inhibition of proliferation by C/EBPβ may be important for coordinated monocytic differentiation.
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Affiliation(s)
- Romina Gutsch
- Institute of Clinical Chemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany
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20
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Abstract
Genetic screens in Drosophila have been instrumental in distinguishing approximately 390 loci involved in position effect variegation and heterochromatin stabilization. Most of the identified genes [so-called Su(var) and E(var) genes] are also conserved in mammals, where more than 50 of their gene products are known to localize to constitutive heterochromatin. From these proteins, approximately 12 core heterochromatin components can be inferred. In addition, there are approximately 30 additional Su(var) and 10 E(var) factors that can, under distinct developmental options, interchange with constitutive heterochromatin and participate in the partitioning of the genome into repressed and active chromatin domains. A significant fraction of the Su(var) and E(var) factors are enzymes that respond to environmental and metabolic signals, thereby allowing both the variation and propagation of epigenetic states to a dynamic chromatin template. Moreover, the misregulation of human SU(VAR) and E(VAR) function can advance cancer and many other human diseases including more complex disorders. As such, mammalian Su(var) and E(var) genes and their products provide a rich source of novel targets for diagnosis of and pharmaceutical intervention in many human diseases.
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Affiliation(s)
- Barna D Fodor
- Max-Planck Institute of Immunobiology, D-79108 Freiburg, Germany.
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21
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DNA binding sites target nuclear NFATc1 to heterochromatin regions in adult skeletal muscle fibers. Histochem Cell Biol 2010; 134:387-402. [PMID: 20865272 DOI: 10.1007/s00418-010-0744-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2010] [Indexed: 10/19/2022]
Abstract
We have previously demonstrated that Ca²+/calcineurin-dependent dephosphorylation of the transcription factor nuclear factor of activated T cells subtype 1 (NFATc1) during repetitive skeletal muscle activity causes NFAT nuclear translocation and concentration in subnuclear NFAT foci. We now show that NFAT nuclear foci colocalize with heterochromatin regions of intense staining by DAPI or TO-PRO-3 that are present in the nucleus prior to NFATc1 nuclear entry. Nuclear NFATc1 also colocalizes with the heterochromatin markers trimethyl-histone H3 (Lys9) and heterochromatin protein 1α. Mutation of the NFATc1 DNA binding sites prevents entry and localization of NFATc1 in heterochromatin regions. However, fluorescence in situ hybridization shows that the NFAT-regulated genes for slow and fast myosin heavy chains are not localized within the heterochromatin regions. Fluorescence recovery after photobleaching shows that within a given nucleus, NFATc1 redistributes relatively rapidly (t(¹/₂) < 1 min) between NFAT foci. Nuclear export of an NFATc1 mutant not concentrated in NFAT foci is accelerated following nuclear entry during fiber activity, indicating buffering of free nuclear NFATc1 by NFATc1 within the NFAT foci. Taken together, our results suggest that NFAT foci serve as nuclear storage sites for NFATc1, allowing it to rapidly mobilize to other nuclear regions as required.
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22
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Lin BS, Tsai PY, Hsieh WY, Tsao HW, Liu MW, Grenningloh R, Wang LF, Ho IC, Miaw SC. SUMOylation attenuates c-Maf-dependent IL-4 expression. Eur J Immunol 2010; 40:1174-84. [PMID: 20127678 DOI: 10.1002/eji.200939788] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The function of transcription factors can be critically regulated by SUMOylation. c-Maf, the cellular counterpart of v-maf oncogene, is a potent transactivator of the IL-4 gene in Th2 cells. We found in a yeast two-hybrid screen that c-Maf can interact with Ubc9 and PIAS1, two key enzymes of the SUMOylation pathway. In this study, we report that c-Maf co-localized with these two SUMO (small ubiquitin-like modifier) ligases in the nucleus and that c-Maf can be SUMOylated in vitro and also in primary Th2 cells. We also demonstrated that lysine-33 is the dominant, if not the only, SUMO acceptor site of c-Maf. SUMOylation of c-Maf attenuated its transcriptional activity. Reciprocally, a SUMOylation resistant c-Maf was more potent than WT-c-Maf in driving IL-4 production in c-Maf-deficient Th2 cells. Furthermore, we showed that ablation of the SUMO site did not alter the subcellular localization or the stability of c-Maf protein but instead enhanced its recruitment to the Il4-promoter. We conclude that SUMOylation at lysine-33 is a functionally critical post-translational modification event of c-Maf in Th cells.
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Affiliation(s)
- Bo-Shiou Lin
- Graduate Institute of Immunology, National Taiwan University College of Medicine, Taipei, Taiwan
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23
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Laureys G, Clinckers R, Gerlo S, Spooren A, Wilczak N, Kooijman R, Smolders I, Michotte Y, De Keyser J. Astrocytic beta(2)-adrenergic receptors: from physiology to pathology. Prog Neurobiol 2010; 91:189-99. [PMID: 20138112 DOI: 10.1016/j.pneurobio.2010.01.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 12/07/2009] [Accepted: 01/27/2010] [Indexed: 12/24/2022]
Abstract
Evidence accumulates for a key role of the beta(2)-adrenergic receptors in the many homeostatic and neuroprotective functions of astrocytes, including glycogen metabolism, regulation of immune responses, release of neurotrophic factors, and the astrogliosis that occurs in response to neuronal injury. A dysregulation of the astrocytic beta(2)-adrenergic-pathway is suspected to contribute to the physiopathology of a number of prevalent and devastating neurological conditions such as multiple sclerosis, Alzheimer's disease, human immunodeficiency virus encephalitis, stroke and hepatic encephalopathy. In this review we focus on the physiological functions of astrocytic beta(2)-adrenergic receptors, and their possible impact in disease states.
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Affiliation(s)
- Guy Laureys
- Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Belgium
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24
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Ravimohan S, Gama L, Barber SA, Clements JE. Regulation of SIV mac 239 basal long terminal repeat activity and viral replication in macrophages: functional roles of two CCAAT/enhancer-binding protein beta sites in activation and interferon beta-mediated suppression. J Biol Chem 2009; 285:2258-73. [PMID: 19933495 DOI: 10.1074/jbc.m109.075929] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
CCAAT/enhancer-binding protein (C/EBP) beta and C/EBP sites in the HIV-1 long terminal repeat (LTR) are crucial for HIV-1 replication in monocyte/macrophages and for the ability of interferon beta (IFN beta) to inhibit ongoing active HIV replication in these cells. This IFN beta-mediated down-regulation involves induction of the truncated, dominant-negative isoform of C/EBP beta referred to as liver-enriched transcriptional inhibitory protein (LIP). Although binding of the C/EBP beta isoform to C/EBP sites in the simian immunodeficiency virus (SIV) LTR has previously been examined, the importance of these sites in core promoter-mediated transcription, virus replication, IFN beta-mediated regulation, and the relative binding of the two isoforms (C/EBP beta and LIP) has not been investigated. Here, we specifically examine two C/EBP sites, JC1 (-100 bp) and DS1 (+134 bp), located within the minimal region of the SIV LTR, required for core promoter-mediated transcription and virus replication in macrophages. Our studies revealed that the JC1 but not DS1 C/EBP site is important for basal level transcription, whereas the DS1 C/EBP site is imperative for productive virus replication in primary macrophages. In contrast, either JC1 or DS1 C/EBP site is sufficient to mediate IFN beta-induced down-regulation of SIV LTR activity and virus replication in these cells. We also characterized the differential binding properties of C/EBP beta and LIP to the JC1 and DS1 sites. In conjunction with previous studies from our laboratory, we demonstrate the importance of these sites in virus gene expression, and we propose a model for their role in establishing latency and persistence in macrophages in the brain.
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Affiliation(s)
- Shruthi Ravimohan
- McKusick-Nathans Institute of Genetic Medicine and Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Wethkamp N, Klempnauer KH. Daxx is a transcriptional repressor of CCAAT/enhancer-binding protein beta. J Biol Chem 2009; 284:28783-94. [PMID: 19690170 DOI: 10.1074/jbc.m109.041186] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
CCAAT/enhancer-binding Protein beta (C/EBPbeta) is a member of the bZIP transcription factor family that is expressed in various tissues, including cells of the hematopoietic system. C/EBPbeta is involved in tissue-specific gene expression and thereby takes part in fundamental cellular processes such as proliferation and differentiation. Here, we show that the activity of C/EBPbeta is negatively regulated by the transcriptional co-repressor Daxx. C/EBPbeta was found to directly interact with Daxx after overexpression as well as on the endogenous level. Glutathione S-transferase pulldown assays showed that Daxx binds via amino acids 190-400 to the C-terminal part of C/EBPbeta. Co-expression of C/EBPbeta changed the sub-nuclear Daxx distribution pattern from predominantly POD-localized to nucleoplasmic. Daxx suppressed basal and p300-enhanced transcriptional activity of C/EBPbeta. Furthermore, Daxx decreased the C/EBPbeta-dependent phosphorylation of p300, which in turn was associated with a diminished level of p300-mediated C/EBPbeta acetylation. Co-expression of promyelocytic leukemia protein abrogated the repressive effect of Daxx on C/EBPbeta as well as the direct interaction of Daxx and C/EBPbeta, presumably by re-recruiting Daxx to PML-oncogenic domains. In acute promyelocytic leukemia (APL) cells, C/EBPbeta activity is known to be required for all-trans-retinoic acid-induced cell differentiation and disease remission. We show that all-trans-retinoic acid as well as arsenic trioxide treatment leads to a reduced C/EBPbeta fraction associated with Daxx suggesting a relief of Daxx-dependent C/EBPbeta repression as an important molecular event leading to APL cell differentiation. Overall, our data identify Daxx as a new negative regulator of C/EBPbeta and provide first clues for a link between abrogation of Daxx-C/EBPbeta complex formation and APL remission.
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Affiliation(s)
- Nils Wethkamp
- Institut für Biochemie, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 2, Münster D-48149, Germany
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Ranjan R, Thompson EA, Yoon K, Smart RC. C/EBPalpha expression is partially regulated by C/EBPbeta in response to DNA damage and C/EBPalpha-deficient fibroblasts display an impaired G1 checkpoint. Oncogene 2009; 28:3235-45. [PMID: 19581927 PMCID: PMC2741539 DOI: 10.1038/onc.2009.176] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We observed that C/EBPα is highly inducible in primary fibroblasts by DNA damaging agents that induce strand breaks, alkylate and crosslink DNA as well as those that produce bulky DNA lesions. Fibroblasts deficient in C/EBPα (C/EBPα-/-) display an impaired G1 checkpoint as evidenced by inappropriate entry into S-phase in response to DNA damage and these cells also display an enhanced G1 to S transition in response to mitogens. The induction of C/EBPα by DNA damage in fibroblasts does not require p53. EMSA analysis of nuclear extracts prepared from UVB- and MNNG-treated fibroblasts revealed increased binding of C/EBPβ to a C/EBP consensus sequence and ChIP analysis revealed increased C/EBPβ binding to the C/EBPα promoter. To determine whether C/EBPβ has a role in the regulation of C/EBPα we treated C/EBPβ-/- fibroblasts with UVB or MNNG. We observed C/EBPα induction was impaired in both UVB- and MNNG- treated C/EBPβ-/- fibroblasts. Our study reveals a novel role for C/EBPβ in the regulation of C/EBPα in response to DNA damage and provides definitive genetic evidence that C/EBPα has a critical role in the DNA damage G1 checkpoint.
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Affiliation(s)
- R Ranjan
- Cell Signaling and Cancer Group, Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695-7633, USA
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Leavenworth JW, Ma X, Mo YY, Pauza ME. SUMO conjugation contributes to immune deviation in nonobese diabetic mice by suppressing c-Maf transactivation of IL-4. THE JOURNAL OF IMMUNOLOGY 2009; 183:1110-9. [PMID: 19553542 DOI: 10.4049/jimmunol.0803671] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
It is not clear why the development of protective Th2 cells is poor in type 1 diabetes (T1D). c-Maf transactivates the IL-4 gene promoting Th2 cell development; therefore, abnormalities in c-Maf may contribute to reduced IL-4 production by CD4 cells from nonobese diabetic (NOD) mice. In this study we demonstrate that despite normal expression, c-Maf binds poorly to the IL-4 promoter (IL-4p) in NOD CD4 cells. Immunoblotting demonstrates that c-Maf can be modified at lysine 33 by SUMO-1 (small ubiquitin-like modifier 1). Sumoylation is facilitated by direct interaction with the E2-conjugating enzyme Ubc9 and increases following T cell stimulation. In transfected cells, sumoylation decreases c-Maf transactivation of IL-4p-driven luciferase reporter activity, reduces c-Maf binding to the IL-4p in chromatin immunoprecipitation assays, and enhances c-Maf localization into promyelocytic leukemia nuclear bodies. Sumoylation of c-Maf is increased in NOD CD4 cells as compared with CD4 cells from diabetes-resistant B10.D2 mice, suggesting that increased c-Maf sumoylation contributes to immune deviation in T1D by reducing c-Maf access to and transactivation of the IL-4 gene.
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Affiliation(s)
- Jianmei W Leavenworth
- Department of Medical Microbiology, Immunology, and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62702, USA
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Liu Y, Nonnemacher MR, Wigdahl B. CCAAT/enhancer-binding proteins and the pathogenesis of retrovirus infection. Future Microbiol 2009; 4:299-321. [PMID: 19327116 DOI: 10.2217/fmb.09.4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Previous studies indicate that two upstream CCAAT/enhancer-binding protein (C/EBP) sites and C/EBPbeta are required for subtype B HIV-1 gene expression in cells of the monocyte-macrophage lineage. The mechanisms of C/EBP regulation of HIV-1 transcription and replication remain unclear. This review focuses on studies concerning the role of C/EBP factors in HIV-1, human T-cell leukemia virus type 1, and SIV transcription in various cell types and tissues cultured in vitro, animal models and during human infection. The structure and function of the C/EBPbeta gene and the related protein isoforms are discussed along with the transcription factors, coactivators, viral proteins, cytokines and chemokines that affect C/EBP function.
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Affiliation(s)
- Yujie Liu
- Department of Microbiology & Immunology, Center for Molecular Virology & Neuroimmunology, Center for Cancer Biology, Philadelphia, PA 19129, USA
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CCAAT/enhancer-binding protein beta: its role in breast cancer and associations with receptor tyrosine kinases. Expert Rev Mol Med 2009; 11:e12. [PMID: 19351437 DOI: 10.1017/s1462399409001033] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The CCAAT/enhancer-binding proteins (C/EBPs) are a family of leucine-zipper transcription factors that regulate gene expression to control cellular proliferation, differentiation, inflammation and metabolism. Encoded by an intronless gene, C/EBPbeta is expressed as several distinct protein isoforms (LAP1, LAP2, LIP) whose expression is regulated by the differential use of several in-frame translation start sites. LAP1 and LAP2 are transcriptional activators and are associated with differentiation, whereas LIP is frequently elevated in proliferative tissue and acts as a dominant-negative inhibitor of transcription. However, emerging evidence suggests that LIP can serve as a transcriptional activator in some cellular contexts, and that LAP1 and LAP2 might also have unique actions. The LIP:LAP ratio is crucial for the maintenance of normal growth and development, and increases in this ratio lead to aggressive forms of breast cancer. This review discusses the regulation of C/EBPbeta activity by post-translational modification, the individual actions of LAP1, LAP2 and LIP, and the functions and downstream targets that are unique to each isoform. The role of the C/EBPbeta isoforms in breast cancer is discussed and emphasis is placed on their interactions with receptor tyrosine kinases.
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Akar CA, Feinstein DL. Modulation of inducible nitric oxide synthase expression by sumoylation. J Neuroinflammation 2009; 6:12. [PMID: 19323834 PMCID: PMC2667488 DOI: 10.1186/1742-2094-6-12] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Accepted: 03/26/2009] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND In astrocytes, the inflammatory induction of Nitric Oxide Synthase type 2 (NOS2) is inhibited by noradrenaline (NA) at the transcriptional level however its effects on specific transcription factors are not fully known. Recent studies show that the activity of several transcription factors including C/EBPbeta, which is needed for maximal NOS2 expression, is modulated by conjugation of the small molecular weight protein SUMO. We examined whether the expression of SUMO Related Genes (SRGs: SUMO-1, the conjugating enzyme Ubc9, and the protease SENP1) are affected by inflammatory conditions or NA and whether SUMO-1 regulates NOS2 through interaction with C/EBPbeta. METHODS Bacterial endotoxin lipopolysaccharide (LPS) was used to induce inflammatory responses including NOS2 expression in primary astrocytes. The mRNA levels of SRGs were determined by QPCR. A functional role for SUMOylation was evaluated by determining effects of over-expressing SRGs on NOS2 promoter and NFkappaB binding-element reporter constructs. Interactions of SUMO-1 and C/EBPbeta with the NOS2 promoter were examined by chromatin immunoprecipitation assays. Interactions of SUMO-1 with C/EBPbeta were examined by immunoprecipitation and Western blot analysis and by fluorescence resonance energy transfer (FRET) assays. RESULTS LPS decreased mRNA levels of SUMO-1, Ubc9 and SENP1 in primary astrocytes and a similar decrease occurred during normal aging in brain. NA attenuated the LPS-induced reductions and increased SUMO-1 above basal levels. Over-expression of SUMO-1, Ubc9, or SENP1 reduced the activation of a NOS2 promoter, whereas activation of a 4 x NFkappaB binding-element reporter was only reduced by SUMO-1. ChIP studies revealed interactions of SUMO-1 and C/EBPbeta with C/EBP binding sites on the NOS2 promoter that were modulated by LPS and NA. SUMO-1 co-precipitated with C/EBPbeta and a close proximity was confirmed by FRET analysis. CONCLUSION Our results demonstrate that SUMOylation regulates NOS2 expression in astrocytes, and point to modification of C/EBPbeta as a possible mechanism of action. Targeting the SUMOylation pathway may therefore offer a novel means to regulate inflammatory NOS2 expression in neurological conditions and diseases.
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Affiliation(s)
- Candan A Akar
- Department of Anesthesiology, University of Illinois, Chicago, IL 60612, USA.
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Nayak A, Glöckner-Pagel J, Vaeth M, Schumann JE, Buttmann M, Bopp T, Schmitt E, Serfling E, Berberich-Siebelt F. Sumoylation of the transcription factor NFATc1 leads to its subnuclear relocalization and interleukin-2 repression by histone deacetylase. J Biol Chem 2009; 284:10935-46. [PMID: 19218564 DOI: 10.1074/jbc.m900465200] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The family of NFAT (nuclear factor of activated T-cells) transcription factors plays an important role in cytokine gene regulation. In peripheral T-cells NFATc1 and -c2 are predominantly expressed. Because of different promoter and poly(A) site usage as well as alternative splicing events, NFATc1 is synthesized in multiple isoforms. The highly inducible NFATc1/A contains a relatively short C terminus, whereas the longer, constitutively expressed isoform NFATc1/C spans an extra C-terminal peptide of 246 amino acids. Interestingly, this NFATc1/C-specific terminus can be highly sumoylated. Upon sumoylation, NFATc1/C, but not the unsumoylated NFATc1/A, translocates to promyelocytic leukemia nuclear bodies. This leads to interaction with histone deacetylases followed by deacetylation of histones, which in turn induces transcriptionally inactive chromatin. As a consequence, expression of the NFATc1 target gene interleukin-2 is suppressed. These findings demonstrate that the modification by SUMO (small ubiquitin-like modifier) converts NFATc1 from an activator to a site-specific transcriptional repressor, revealing a novel regulatory mechanism for NFATc1 function.
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Affiliation(s)
- Arnab Nayak
- Departments of Molecular Pathology and Neurology, Julius Maximilians-University, 97080 Wuerzburg and Institute of Immunology, Johannes Gutenberg-University, 55131 Mainz, Germany
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Pless O, Kowenz-Leutz E, Knoblich M, Lausen J, Beyermann M, Walsh MJ, Leutz A. G9a-mediated lysine methylation alters the function of CCAAT/enhancer-binding protein-beta. J Biol Chem 2008; 283:26357-63. [PMID: 18647749 DOI: 10.1074/jbc.m802132200] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The functional capacity of the transcriptional regulatory CCAAT/enhancer-binding protein-beta (C/EBPbeta) is governed by protein interactions and post-translational protein modifications. In a proteome-wide interaction screen, the histone-lysine N-methyltransferase, H3 lysine 9-specific 3 (G9a), was found to directly interact with the C/EBPbeta transactivation domain (TAD). Binding between G9a and C/EBPbeta was confirmed by glutathione S-transferase pulldown and co-immunoprecipitation. Metabolic labeling showed that C/EBPbeta is post-translationally modified by methylation in vivo. A conserved lysine residue in the C/EBPbeta TAD served as a substrate for G9a-mediated methylation. G9a, but not a methyltransferase-defective G9a mutant, abrogated the transactivation potential of wild type C/EBPbeta. A C/EBPbeta TAD mutant that contained a lysine-to-alanine exchange was resistant to G9a-mediated inhibition. Moreover, the same mutation conferred super-activation of a chromatin-embedded, endogenous C/EBPbeta target gene. Our data identify C/EBPbeta as a direct substrate of G9a-mediated post-translational modification that alters the functional properties of C/EBPbeta during gene regulation.
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Affiliation(s)
- Ole Pless
- Max Delbrück Center for Molecular Medicine, Humboldt University of Berlin, Berlin, Germany
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C/EBPs: recipients of extracellular signals through proteome modulation. Curr Opin Cell Biol 2008; 20:180-5. [DOI: 10.1016/j.ceb.2008.02.002] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/05/2008] [Accepted: 02/06/2008] [Indexed: 12/27/2022]
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Hsu YHR, Sarker KP, Pot I, Chan A, Netherton SJ, Bonni S. Sumoylated SnoN represses transcription in a promoter-specific manner. J Biol Chem 2006; 281:33008-18. [PMID: 16966324 DOI: 10.1074/jbc.m604380200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The transcriptional modulator SnoN controls a diverse set of biological processes, including cell proliferation and differentiation. The mechanisms by which SnoN regulates these processes remain incompletely understood. Recent studies have shown that SnoN exerts positive or negative regulatory effects on transcription. Because post-translational modification of proteins by small ubiquitin-like modifier (SUMO) represents an important mechanism in the control of the activity of transcriptional regulators, we asked if this modification regulates SnoN function. Here, we show that SnoN is sumoylated. Our data demonstrate that the SUMO-conjugating E2 enzyme Ubc9 is critical for SnoN sumoylation and that the SUMO E3 ligase PIAS1 selectively interacts with and enhances the sumoylation of SnoN. We identify lysine residues 50 and 383 as the SUMO acceptor sites in SnoN. Analyses of SUMO "loss-of-function" and "gain-of-function" SnoN mutants in transcriptional reporter assays reveal that sumoylation of SnoN contributes to the ability of SnoN to repress gene expression in a promoter-specific manner. Although this modification has little effect on SnoN repression of the plasminogen activator inhibitor-1 promoter and only modestly potentiates SnoN repression of the p21 promoter, SnoN sumoylation robustly augments the ability of SnoN to suppress transcription of the myogenesis master regulatory gene myogenin. In addition, we show that the SnoN SUMO E3 ligase, PIAS1, at its endogenous levels, suppresses myogenin transcription. Collectively, our findings suggest that SnoN is directly regulated by sumoylation leading to the enhancement of the ability of SnoN to repress transcription in a promoter-specific manner. Our study also points to a physiological role for SnoN sumoylation in the control of myogenin expression in differentiating muscle cells.
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Affiliation(s)
- Ying-Han R Hsu
- Southern Alberta Cancer Research Institute and Department of Biochemistry & Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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