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Liu P, Shi C, Qiu L, Shang D, Lu Z, Tu Z, Liu H. Menin signaling and therapeutic targeting in breast cancer. Curr Probl Cancer 2024; 51:101118. [PMID: 38968834 DOI: 10.1016/j.currproblcancer.2024.101118] [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: 01/17/2024] [Accepted: 06/26/2024] [Indexed: 07/07/2024]
Abstract
To date, mounting evidence have shown that patients with multiple endocrine neoplasia type 1 (MEN1) may face an increased risk for breast carcinogenesis. The product of the MEN1 gene, menin, was also indicated to be an important regulator in breast cancer signaling network. Menin directly interacts with MLL, EZH2, JunD, NF-κB, PPARγ, VDR, Smad3, β-catenin and ERα to modulate gene transcriptions leading to cell proliferation inhibition. Moreover, interaction of menin-FANCD2 contributes to the enhancement of BRCA1-mediated DNA repair mechanism. Ectopic expression of menin causes Bax-, Bak- and Caspase-8-dependent apoptosis. However, despite numbers of menin inhibitors were exploited in other cancers, data on the usage of menin inhibitors in breast cancer treatment remain limited. In this review, we focused on the menin associated signaling pathways and gene transcription regulations, with the aim of elucidating its molecular mechanisms and of guiding the development of novel menin targeted drugs in breast cancer therapy.
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Affiliation(s)
- Peng Liu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Chaowen Shi
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Lipeng Qiu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Dongsheng Shang
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Ziwen Lu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Zhigang Tu
- School of Life Sciences, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Hanqing Liu
- School of Pharmacy, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
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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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3
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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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Wang W, Yang C, Lin S, Vellaisamy K, Li G, Tan W, Leung CH, Ma DL. First Synthesis of an Oridonin-Conjugated Iridium(III) Complex for the Intracellular Tracking of NF-κB in Living Cells. Chemistry 2017; 23:4929-4935. [DOI: 10.1002/chem.201700770] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Indexed: 01/22/2023]
Affiliation(s)
- Wanhe Wang
- Department of Chemistry; Hong Kong Baptist University, Kowloon Tong; Hong Kong P. R. China
| | - Chao Yang
- State Key Laboratory of Quality Research in Chinese Medicine; Institute of Chinese Medical Sciences; University of Macau; Macao P. R. China
| | - Sheng Lin
- Department of Chemistry; Hong Kong Baptist University, Kowloon Tong; Hong Kong P. R. China
| | - Kasipandi Vellaisamy
- Department of Chemistry; Hong Kong Baptist University, Kowloon Tong; Hong Kong P. R. China
| | - Guodong Li
- State Key Laboratory of Quality Research in Chinese Medicine; Institute of Chinese Medical Sciences; University of Macau; Macao P. R. China
| | - Weihong Tan
- Department of Chemistry, and Department of Physiology and Functional Genomics; Center for Research at the Bio/Nano Interface; Shands Cancer Center; UF Genetics Institute; McKnight Brain Institute; University of Florida; Gainesville USA
- Molecular Sciences and Biomedicine Laboratory; State Key Laboratory for Chemo/Biosensing and Chemometrics, Department of Chemistry; College of Chemistry and Chemical Engineering, College of Biology; Collaborative Innovation Center for Molecular Engineering and Theranostics; Hunan University; Changsha P. R. China
| | - Chung-Hang Leung
- State Key Laboratory of Quality Research in Chinese Medicine; Institute of Chinese Medical Sciences; University of Macau; Macao P. R. China
| | - Dik-Lung Ma
- Department of Chemistry; Hong Kong Baptist University, Kowloon Tong; Hong Kong P. R. China
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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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Xia P, Zhang R, Ge G. C/EBPβ Mediates TNF-α-Induced Cancer Cell Migration by Inducing MMP Expression Dependent on p38 MAPK. J Cell Biochem 2016; 116:2766-77. [PMID: 25959126 DOI: 10.1002/jcb.25219] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/05/2015] [Indexed: 01/01/2023]
Abstract
Tumor necrosis factor (TNF)-α is a pleiotropic cytokine that triggers cell proliferation, cell death, or inflammation. Besides its cytotoxic effect on cancer cells, TNF-α exerts tumor promoting activity. Aberrant TNF-α signaling promotes cancer cell motility, invasiveness, and enhances cancer metastasis. Exaggerated tumor cell migration, invasion, and metastasis by TNF-α has been attributed to the activation of NF-κB signaling. It is yet to be elucidated if other signaling pathways and effector molecules are involved in TNF-α-induced cancer cell migration and metastasis. Expression of C/EBPβ, a transcription factor involved in metabolism, inflammation, and cancer, is increased upon TNF-α treatment. TNF-α induces C/EBPβ expression by enhancing its transcription and protein stability. Activation of p38 MAPK, but not NF-κB or JNK, is responsible for TNF-α-induced stabilization of C/EBPβ protein. C/EBPβ is involved in TNF-α-induced cancer cell migration. Knockdown of C/EBPβ inhibits TNF-α-induced cell migration, while overexpression of C/EBPβ increases migration of cancer cells. C/EBPβ is translated into transcriptional activator LAP1 and LAP2 and transcriptional repressor LIP utilizing alternative in-frame translation start sites. Despite TNF-α induces expression of all three isoforms, LAP1/2, but not LIP, promote cancer cell migration. TNF-α induced MMP1/3 expression, which was abrogated by C/EBPβ knockdown or p38 MAPK inhibition. MMP inhibitor or knockdown of MMP1/3 diminished TNF-α- and C/EBPβ-induced cell migration. Thus, C/EBPβ mediates TNF-α-induced cancer cell migration by inducing MMP1/3 expression, and may participate in the regulation of inflammation-associated cancer metastasis.
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Affiliation(s)
- Peiyi Xia
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
| | - Rui Zhang
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
| | - Gaoxiang Ge
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
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Xu T, Shen X, Seyfert HM. Stearoyl-CoA desaturase 1 expression is downregulated in liver and udder during E. coli mastitis through enhanced expression of repressive C/EBP factors and reduced expression of the inducer SREBP1A. BMC Mol Biol 2016; 17:16. [PMID: 27439381 PMCID: PMC4955114 DOI: 10.1186/s12867-016-0069-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 07/13/2016] [Indexed: 01/21/2023] Open
Abstract
Background Stearoyl-CoA desaturase 1 (SCD1) desaturates long chain fatty acids and is therefore a key enzyme in fat catabolism. Its synthesis is downregulated in liver during illnesses caused by high levels of circulating lipopolysaccharide (LPS). SCD1 expression is known to be stimulated under adipogenic conditions through a variety of transcription factors, notably SREBP1 and C/EBPα and −β. However, mechanisms downregulating SCD1 expression during illness related reprograming of the metabolism were unknown. Escherichia coli elicited mastitis is an example of such a condition and was found to downregulates milk and milk fat synthesis. This is in part mediated through epigenetic mechanisms. We analyzed here mechanism controlling SCD1 expression in livers and udders from cows suffering from experimentally induced E. coli mastitis. Results We validated with RT-qPCR that SCD1 expression was reduced in these organs of the experimental cows. They also featured decreased levels of mRNAs encoding SREBP1a but increased levels for C/EBP α and −β. Chromatin accessibility PCR (CHART) revealed that downregulation of SCD1 expression in liver was not caused by tighter chromatin compaction of the SCD1 promoter. Reporter gene analyses showed in liver (HepG2) and mammary epithelial (MAC-T) model cells that overexpression of SREBP1a expectedly activated the promoter, while unexpectedly C/EBPα and −β strongly quenched the promoter activity. Abrogation of two from among of the three C/EBP DNA-binding motifs of the promoter revealed that C/EBPα acts in cis but C/EBPβ in trans. Overexpressing truncated C/EBPα or −β factors lacking their repressive domains confirmed in both model cells the direct action of C/EBPα, but not of C/EBPβ on the promoter. Conclusions We found no evidence that epigenetic mechanism remodeling the chromatin compaction of the SCD1 promoter would contribute to downregulate SCD1 expression during infection. Instead, our data show for the first time that C/EBP factors may repress SCD1 expression in liver and udder rather than stimulating as it was previously shown in adipocytes. This cell type specific dual and opposite function of C/EBP factors for regulating SCD1 expression was previously unknown. Infection related activation of their expression combined with downregulated expression of SREBP1a explains reduced SCD1 expression in liver and udder during acute mastitis. Electronic supplementary material The online version of this article (doi:10.1186/s12867-016-0069-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tianle Xu
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.,College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, People's Republic of China
| | - Xiangzhen Shen
- College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, People's Republic of China
| | - Hans-Martin Seyfert
- Leibniz Institute for Farm Animal Biology, Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196, Dummerstorf, Germany.
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8
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Protein Phosphatase 2A in Lipopolysaccharide-Induced Cyclooxygenase-2 Expression in Murine Lymphatic Endothelial Cells. PLoS One 2015; 10:e0137177. [PMID: 26317424 PMCID: PMC4552685 DOI: 10.1371/journal.pone.0137177] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/14/2015] [Indexed: 02/07/2023] Open
Abstract
The lymphatic endothelium plays an important role in the maintenance of tissue fluid homeostasis. It also participates in the pathogenesis of several inflammatory diseases. However, little is known about the underlying mechanisms by which lymphatic endothelial cell responds to inflammatory stimuli. In this study, we explored the mechanisms by which lipopolysaccharide (LPS) induces cyclooxygenase (COX)-2 expression in murine lymphatic endothelial cells (SV-LECs). LPS caused increases in cox-2 mRNA and protein levels, as well as in COX-2 promoter luciferase activity in SV-LECs. These actions were associated with protein phosphatase 2A (PP2A), apoptosis signal-regulating kinase 1 (ASK1), JNK1/2 and p38MAPK activation, and NF-κB subunit p65 and C/EBPβ phosphorylation. PP2A-ASK1 signaling blockade reduced LPS-induced JNK1/2, p38MAPK, p65 and C/EBPβ phosphorylation. Transfection with PP2A siRNA reduced LPS's effects on p65 and C/EBPβ binding to the COX-2 promoter region. Transfected with the NF-κB or C/EBPβ site deletion of COX-2 reporter construct also abrogated LPS's enhancing effect on COX-2 promoter luciferase activity in SV-LECs. Taken together, the induction of COX-2 in SV-LECs exposed to LPS may involve PP2A-ASK1-JNK and/or p38MAPK-NF-κB and/or C/EBPβ cascade.
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9
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Zante MD, Borchel A, Brunner RM, Goldammer T, Rebl A. Cloning and characterization of the proximal promoter region of rainbow trout (Oncorhynchus mykiss) interleukin-6 gene. FISH & SHELLFISH IMMUNOLOGY 2015; 43:249-256. [PMID: 25549935 DOI: 10.1016/j.fsi.2014.12.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 12/15/2014] [Accepted: 12/18/2014] [Indexed: 06/04/2023]
Abstract
Interleukin-6 (IL6) is a pleiotropic cytokine with important immunoregulatory functions. Its expression is inducible in immune cells and tissues of several fish species. We also found that IL6 mRNA abundance was significantly increased in spleen, liver, and gill of rainbow trout after experimental infection with Aeromonas salmonicida. Genomic DNA sequences of IL6 orthologs from three salmonid species revealed a conserved exon/intron structure and a high overall nucleotide identity of >88%. To uncover key mechanisms regulating IL6 expression in salmonid fish, we amplified a fragment of the proximal IL6 promoter from rainbow trout and identified in-silico conserved binding sites for NF-κB and CEBP. The activity of this IL6 promoter fragment was analyzed in the established human embryonic kidney line HEK-293. Luciferase- and GFP-based reporter systems revealed that the proximal IL6 promoter is activated by Escherichia coli. Essentially, both reporter systems proved that NF-κB p50, but not NF-κB p65 or CEBP, activates the IL6 promoter fragment. Truncation of this fragment caused a significant decrease in IL6 promoter activation. This characterization of the proximal promoter of the IL6-encoding gene provides basic knowledge about the IL6 gene expression in rainbow trout.
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Affiliation(s)
- Merle D Zante
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Andreas Borchel
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Ronald M Brunner
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Tom Goldammer
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Alexander Rebl
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
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10
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Yamaguchi J, Tanaka T, Eto N, Nangaku M. Inflammation and hypoxia linked to renal injury by CCAAT/enhancer-binding protein δ. Kidney Int 2015; 88:262-75. [PMID: 25692954 PMCID: PMC4526770 DOI: 10.1038/ki.2015.21] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 12/08/2014] [Accepted: 12/11/2014] [Indexed: 12/11/2022]
Abstract
Tubulointerstitial hypoxia plays a critical role in the pathogenesis of kidney injury, and hypoxia-inducible factor (HIF)-1 is a master regulator of cellular adaptation to hypoxia. Aside from oxygen molecules, factors that modify HIF-1 expression and functional operation remain obscure. Therefore, we sought to identify novel HIF-1-regulating genes in kidney. A short-hairpin RNA library consisting of 150 hypoxia-inducible genes was derived from a microarray analysis of the rat renal artery stenosis model screened for the effect on HIF-1 response. We report that CCAAT/enhancer-binding protein δ (CEBPD), a transcription factor and inflammatory response gene, is a novel HIF-1 regulator in kidney. CEBPD was induced in the nuclei of tubular epithelial cells in both acute and chronic hypoxic kidneys. In turn, CEBPD induction augmented HIF-1α expression and its transcriptional activity. Mechanistically, CEBPD directly bound to the HIF-1α promoter and enhanced its transcription. Notably, CEBPD was rapidly induced by inflammatory cytokines, such as IL-1β in a nuclear factor-κB-dependent manner, which not only increased HIF-1α expression during hypoxia, but was also indispensable for the non-hypoxic induction of HIF-1α. Thus our study provides novel insight into HIF-1 regulation in tubular epithelial cells and offers a potential hypoxia and inflammation link relevant in both acute and chronic kidney diseases.
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Affiliation(s)
- Junna Yamaguchi
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Tetsuhiro Tanaka
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | | | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
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CCAAT/enhancer binding protein β in relation to ER stress, inflammation, and metabolic disturbances. BIOMED RESEARCH INTERNATIONAL 2015; 2015:324815. [PMID: 25699273 PMCID: PMC4324884 DOI: 10.1155/2015/324815] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/12/2014] [Accepted: 12/12/2014] [Indexed: 12/12/2022]
Abstract
The prevalence of the metabolic syndrome and underlying metabolic disturbances increase rapidly in developed countries. Various molecular targets are currently under investigation to unravel the molecular mechanisms that cause these disturbances. This is done in attempt to counter or prevent the negative health consequences of the metabolic disturbances. Here, we reviewed the current knowledge on the role of C/EBP-β in these metabolic disturbances. C/EBP-β deletion in mice resulted in downregulation of hepatic lipogenic genes and increased expression of β-oxidation genes in brown adipose tissue. Furthermore, C/EBP-β is important in the differentiation and maturation of adipocytes and is increased during ER stress and proinflammatory conditions. So far, studies were only conducted in animals and in cell systems. The results found that C/EBP-β is an important transcription factor within the metabolic disturbances of the metabolic system. Therefore, it is interesting to examine the potential role of C/EBP-β at molecular and physiological level in humans.
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12
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Perino A, Pols TWH, Nomura M, Stein S, Pellicciari R, Schoonjans K. TGR5 reduces macrophage migration through mTOR-induced C/EBPβ differential translation. J Clin Invest 2014; 124:5424-36. [PMID: 25365223 DOI: 10.1172/jci76289] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 09/30/2014] [Indexed: 02/06/2023] Open
Abstract
The bile acid-responsive G protein-coupled receptor TGR5 is involved in several metabolic processes, and recent studies suggest that TGR5 activation may promote pathways that are protective against diet-induced diabetes. Here, we investigated the role of macrophage-specific TGR5 signaling in protecting adipose tissue from inflammation and associated insulin resistance. Examination of adipose tissue from obese mice lacking macrophage Tgr5 revealed enhanced inflammation, increased chemokine expression, and higher macrophage numbers compared with control obese animals. Moreover, macrophage-specific deletion of Tgr5 exacerbated insulin resistance in obese animals. Conversely, pharmacological activation of TGR5 markedly decreased LPS-induced chemokine expression in primary macrophages. This reduction was mediated by AKT-dependent activation of mTOR complex 1, which in turn induced the differential translation of the dominant-negative C/EBPβ isoform, liver inhibitory protein (LIP). Overall, these studies reveal a signaling pathway downstream of TGR5 that modulates chemokine expression in response to high-fat diet and suggest that targeting this pathway has the potential to be therapeutically exploited for prevention of chronic inflammatory diseases and type 2 diabetes mellitus.
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Rebl A, Rebl H, Korytář T, Goldammer T, Seyfert HM. The proximal promoter of a novel interleukin-8-encoding gene in rainbow trout (Oncorhynchus mykiss) is strongly induced by CEBPA, but not NF-κB p65. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 46:155-164. [PMID: 24721762 DOI: 10.1016/j.dci.2014.03.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/31/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
Interleukin-8 (IL8) is an immediate-early chemokine that has been well characterized in several fish species. Ten IL8 gene variants have already been described in rainbow trout, but none of their promoters has structurally been defined or functionally characterized in teleost fish. To uncover key factors regulating IL8 expression, we intended to functionally characterize an IL8 promoter from rainbow trout. Incidentally, we isolated a novel IL8 gene variant (IL8-G). It is structurally highly similar to the other trout IL8 gene variants and its mRNA concentration increased significantly in secondary lymphoid tissues after infecting healthy fish with Aeromonas salmonicida. The proximal promoter sequence of the IL8-G-encoding gene features in close proximity two consensus elements for CEBP attachment. The proximal site overlaps with a NF-κB-binding site. Cotransfection of an IL8-G promoter-driven reporter gene together with vectors expressing various mammalian CEBP or NF-κB factors revealed in human HEK-293 cells that CEBPA and NF-κB p50, but not NF-κB p65 activate this promoter. The stimulatory effect of NF-κB p50 is likely conveyed by synergizing with CEBPA. Deletion or mutation of either the distal or the proximal CEBP-binding site, respectively, caused a significant decrease in IL8-G promoter activation. We confirmed the significance of the CEBPA factor for IL8-G expression by comparing the stimulatory capacity of the trout CEBPA and -B factors, thereby reducing the evolutionary distance in the inter-species expression assays. Similar promoter induction potential and intracellular localization of the mammalian and teleostean CEBPA and -B factors suggests their functional conservation throughout evolution.
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Affiliation(s)
- Alexander Rebl
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Henrike Rebl
- Rostock University Medical Center, Department of Cell Biology, Schillingallee 69, 18057 Rostock, Germany
| | - Tomáš Korytář
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Immunology, Südufer 10, 17493 Greifswald-Insel Riems, Germany
| | - Tom Goldammer
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany
| | - Hans-Martin Seyfert
- Leibniz Institute for Farm Animal Biology (FBN), Institute for Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
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Shah S, Alexaki A, Pirrone V, Dahiya S, Nonnemacher MR, Wigdahl B. Functional properties of the HIV-1 long terminal repeat containing single-nucleotide polymorphisms in Sp site III and CCAAT/enhancer binding protein site I. Virol J 2014; 11:92. [PMID: 24886416 PMCID: PMC4047001 DOI: 10.1186/1743-422x-11-92] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 04/25/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND HIV-1 gene expression is driven by the long terminal repeat (LTR), which contains many binding sites shown to interact with an array of host and viral factors. Selective pressures within the host as well as the low fidelity of reverse transcriptase lead to changes in the relative prevalence of genetic variants within the HIV-1 genome, including the LTR, resulting in viral quasispecies that can be differentially regulated and can potentially establish niches within specific cell types and tissues. METHODS Utilizing flow cytometry and electromobility shift assays, specific single-nucleotide sequence polymorphisms (SNPs) were shown to alter both the phenotype of LTR-driven transcription and reactivation. Additional studies also demonstrated differential loading of transcription factors to probes derived from the double-variant LTR as compared to probes from the wild type. RESULTS This study has identified specific SNPs within CCAAT/enhancer binding protein (C/EBP) site I and Sp site III (3 T, C-to-T change at position 3, and 5 T, C-to-T change at position 5 of the binding site, respectively) that alter LTR-driven gene transcription and may alter the course of viral latency and reactivation. The HIV-1 LAI LTRs containing the SNPs of interest were coupled to a plasmid encoding green fluorescent protein (GFP), and polyclonal HIV-1 LTR-GFP stable cell lines utilizing bone marrow progenitor, T, and monocytic cell lines were constructed and utilized to explore the LTR phenotype associated with these genotypic changes. CONCLUSIONS Although the 3 T and 5 T SNPs have been shown to be low-affinity binding sites, the fact that they can still result in effective HIV-1 LTR-driven gene expression, particularly within the TF-1 cell line, has suggested that the low binding site affinities associated with the 3 T C/EBP site I and 5 T Sp site III are potentially compensated for by the interaction of nuclear factor-κB with its corresponding binding sites under selected physiological and cellular conditions. Additionally, tumor necrosis factor-α and Tat can enhance basal transcription of each SNP-specific HIV-1 LTR; however, differential regulation of the LTR is both SNP- and cell type-specific.
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Affiliation(s)
- Sonia Shah
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
| | - Aikaterini Alexaki
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
| | - Vanessa Pirrone
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
| | - Satinder Dahiya
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, and Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA
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Abstract
Adipose tissue historically was believed to be an inert tissue, functioning primarily in the storage of energy and thermal homeostasis. However, recent discoveries point toward a critical role for adipocytes in endocrine function as well as immune regulation. Excess body fat, accumulated through aging and/or a calorie-rich diet, is associated with many chronic metabolic and inflammatory diseases. Within the stromal vascular fraction of adipose tissue, macrophages and T cells accumulate with increasing tissue mass, secreting pro- or anti-inflammatory cytokines. In this review we discuss the current understanding of immune cell function in both diet-induced and age-related obesity. In both models of obesity, the classically activated, pro-inflammatory (M1) subtype takes precedence over the alternatively activated, anti-inflammatory (M2) macrophages, causing tissue necrosis and releasing pro-inflammatory cytokines like interleukin-6. Other distinct adipose tissue macrophage subtypes have been identified by surface marker expression and their functions characterized. Adipose tissue T cell recruitment to adipose tissue is also different between aging- and diet-induced obesity. Under both conditions, T cells exhibit restricted T-cell receptor diversity and produce higher levels of pro-inflammatory signals like interferon-γ and granzyme B relative to young or healthy mice. However, numbers of regulatory T cells are dramatically different between the 2 models of obesity. Taken together, these findings suggest models of age- and diet-induced obesity may be more distinct than previously thought, with many questions yet to be resolved in this multidimensional disease.
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Affiliation(s)
- Sanjay K Garg
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Colin Delaney
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Hang Shi
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
| | - Raymond Yung
- Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan
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Huang YH, Yang HY, Hsu YF, Chiu PT, Ou G, Hsu MJ. Src contributes to IL6-induced vascular endothelial growth factor-C expression in lymphatic endothelial cells. Angiogenesis 2013; 17:407-18. [DOI: 10.1007/s10456-013-9386-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 09/12/2013] [Indexed: 12/20/2022]
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The serine phosphatase SerB of Porphyromonas gingivalis suppresses IL-8 production by dephosphorylation of NF-κB RelA/p65. PLoS Pathog 2013; 9:e1003326. [PMID: 23637609 PMCID: PMC3630210 DOI: 10.1371/journal.ppat.1003326] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
Porphyromonas gingivalis is a major pathogen in severe and chronic manifestations of periodontal disease, which is one of the most common infections of humans. A central feature of P. gingivalis pathogenicity is dysregulation of innate immunity at the gingival epithelial interface, including suppression of IL-8 production by epithelial cells. NF-κB is a transcriptional regulator that controls important aspects of innate immune responses, and NF-κB RelA/p65 homodimers regulate transcription of IL8. Phosphorylation of the NF-κB p65 subunit protein on the serine 536 residue affects nuclear translocation and transcription of target genes. Here we show that SerB, a haloacid dehalogenase (HAD) family serine phosphatase secreted by P. gingivalis, is produced intracellularly and can specifically dephosphorylate S536 of p65 in gingival epithelial cells. A P. gingivalis mutant lacking SerB was impaired in dephosphorylation of p65 S536, and ectopically expressed SerB bound to p65 and co-localized with p65 in the cytoplasm. Ectopic expression of SerB also resulted in dephosphorylation of p65 with reduced nuclear translocation in TNF-α-stimulated epithelial cells. In contrast, the p105/50 subunit of NF-κB was unaffected by SerB. Co-expression of a constitutively active p65 mutant (S536D) relieved inhibition of nuclear translocation. Both the activity of the IL8 promoter and production of IL-8 were diminished by SerB. Deletion and truncation mutants of SerB lacking the HAD-family enzyme motifs of SerB were unable to dephosphorylate p65, inhibit nuclear translocation or abrogate IL8 transcription. Specific dephosphorylation of NF-κB p65 S536 by SerB, and consequent inhibition of nuclear translocation, provides the molecular basis for a bacterial strategy to manipulate host inflammatory pathways and repress innate immunity at mucosal surfaces. Periodontal diseases are one of the most common infections of humans, and are characterized by gingival inflammation and destruction of the hard and soft tissues that support the tooth, eventually causing tooth loss. Porphyromonas gingivalis is a major pathogen in periodontal diseases and a key pathogenic attribute of this organism is the ability to disrupt host innate immunity. Infection of gingival epithelial cells by P. gingivalis suppresses production of the neutrophil chemokine IL-8. This inhibitory process is associated with the P. gingivalis serine phosphatase, SerB. In this study we show that SerB has a potent and specific ability to inhibit activation the NF-κB transcription factor which regulates IL-8 production. Mechanistically, SerB binds to and dephosphorylates the p65 subunit of NF-κB which prevents nuclear translocation and subsequent transcription of the IL8 gene. Targeting the NF-κB p65 subunit allows P. gingivalis to dampen IL-8 dependent inflammatory responses, facilitate survival and potentially to establish a favorable niche for the entire periodontal microbial community.
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Huong LT, Kobayashi M, Nakata M, Shioi G, Miyachi H, Honjo T, Nagaoka H. In vivo analysis of Aicda gene regulation: a critical balance between upstream enhancers and intronic silencers governs appropriate expression. PLoS One 2013; 8:e61433. [PMID: 23613851 PMCID: PMC3628980 DOI: 10.1371/journal.pone.0061433] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 03/08/2013] [Indexed: 12/12/2022] Open
Abstract
The Aicda gene encodes activation-induced cytidine deaminase (AID). Aicda is strongly transcribed in activated B cells to diversify immunoglobulin genes, but expressed at low levels in various other cells in response to physiological or pathological stimuli. AID’s mutagenic nature has been shown to be involved in tumor development. Here, we used a transgenic strategy with bacterial artificial chromosomes (BACs) to examine the in vivo functions of Aicda regulatory elements, which cluster in two regions: in the first intron (region 2), and approximately 8-kb upstream of the transcription start site (region 4). Deleting either of these regions completely abolished the expression of Aicda-BAC reporters, demonstrating these elements’ critical roles. Furthermore, we found that selectively deleting two C/EBP-binding sites in region 4 inactivated the enhancer activity of the region despite the presence of intact NF-κB-, STAT6- and Smad-binding sites. On the other hand, selectively deleting E2F- and c-Myb-binding sites in region 2 increased the frequency of germinal-center B cells in which the Aicda promoter was active, indicating that E2F and c-Myb act as silencers in vivo. Interestingly, the silencer deletion did not cause ectopic activation of the Aicda promoter, indicating that Aicda activation requires enhancer-specific stimulation. In summary, precise regulation of the Aicda promoter appears to depend on a coordinated balance of activities between enhancer and silencer elements.
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Affiliation(s)
- Le Thi Huong
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Maki Kobayashi
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mikiyo Nakata
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Go Shioi
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Hitoshi Miyachi
- Reproductive Engineering Team, Institute of Virus Research, Kyoto University, Kyoto, Japan
| | - Tasuku Honjo
- Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hitoshi Nagaoka
- Department of Molecular Pathobiochemistry, Gifu University Graduate School of Medicine, Gifu, Japan
- * E-mail:
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Interleukin-10-induced neutrophil gelatinase-associated lipocalin production in macrophages with consequences for tumor growth. Mol Cell Biol 2012; 32:3938-48. [PMID: 22851691 DOI: 10.1128/mcb.00413-12] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tumor cell-derived factors, such as interleukin 10 (IL-10), polarize macrophages toward a regulatory M2 phenotype, characterized by the expression of anti-inflammatory cytokines and protumorigenic mediators. Here we explored molecular mechanisms allowing IL-10 to upregulate the protumorigenic protein NGAL in primary human macrophages. Reporter assays of full-length or deletion constructs of the NGAL promoter provided evidence that NGAL production is STAT3 dependent, activated downstream of the IL-10-Janus kinase (Jak) axis, as well as being C/EBPβ dependent. The involvement of STAT3 and C/EBPβ was shown by chromatin immunoprecipitation (ChIP) and ChIP-Western analysis, as well as decoy oligonucleotides scavenging both STAT3 and C/EBPβ in human macrophages. Furthermore, the production of NGAL in macrophages in response to IL-10 induces cellular growth and proliferation of MCF-7 breast cancer cells. We conclude that both STAT3 and C/EBPβ are needed to elicit IL-10-mediated NGAL expression in primary human macrophages. Macrophage-secreted NGAL shapes the protumorigenic macrophage phenotype to promote growth of MCF-7 breast cancer cells. Our data point to a macrophage-dependent IL-10-STAT3-NGAL axis that might contribute to tumor progression.
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20
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Regulation of C/EBPβ and resulting functions in cells of the monocytic lineage. Cell Signal 2012; 24:1287-96. [DOI: 10.1016/j.cellsig.2012.02.007] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/14/2012] [Indexed: 01/10/2023]
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21
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Roos AB, Berg T, Barton JL, Didon L, Nord M. Airway epithelial cell differentiation during lung organogenesis requires C/EBPα and C/EBPβ. Dev Dyn 2012; 241:911-23. [PMID: 22411169 DOI: 10.1002/dvdy.23773] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND CCAAT/enhancer-binding protein (C/EBP)α is crucial for lung development and differentiation of the pulmonary epithelium. Conversely, no lung defects have been observed in C/EBPβ-deficient mice, although C/EBPβ trans-activate pulmonary genes by binding to virtually identical DNA-sequences as C/EBPα. Thus, the pulmonary phenotype of mice lacking C/EBPβ could be explained by functional replacement with C/EBPα. We investigated whether C/EBPα and C/EBPβ have overlapping functions in regulating lung epithelial differentiation during organogenesis. Epithelial differentiation was assessed in mice with a lung epithelial-specific (SFTPC-Cre-mediated) deletion of C/EBPα (Cebpa(ΔLE) ), C/EBPβ (Cebpb(ΔLE) ), or both genes (Cebpa(ΔLE) ; Cebpb(ΔLE) ). RESULTS Both Cebpa(ΔLE) mice and Cebpa(ΔLE) ; Cebpb(ΔLE) mice demonstrated severe pulmonary immaturity compared to wild-type littermates, while no differences in lung histology or epithelial differentiation were observed in Cebpb(ΔLE) mice. In contrast to Cebpa(ΔLE) mice, Cebpa(ΔLE) ; Cebpb(ΔLE) mice also displayed undifferentiated Clara cells with markedly impaired protein and mRNA expression of Clara cell secretory protein (SCGB1A1), compared to wild-type littermates. In addition, ectopic mucus-producing cells were observed in the conducting airways of Cebpa(ΔLE) ; Cebpb(ΔLE) mice. CONCLUSIONS Our findings demonstrate that C/EBPα and C/EBPβ play pivotal, and partly overlapping roles in determining airway epithelial differentiation, with possible implications for tissue regeneration in lung homeostasis and disease.
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Affiliation(s)
- Abraham B Roos
- Department of Medicine, Respiratory Medicine Unit, Karolinska Institutet, Stockholm, Sweden.
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22
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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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Ramberg V, Tracy LM, Samuelsson M, Nilsson LNG, Iverfeldt K. The CCAAT/enhancer binding protein (C/EBP) δ is differently regulated by fibrillar and oligomeric forms of the Alzheimer amyloid-β peptide. J Neuroinflammation 2011; 8:34. [PMID: 21492414 PMCID: PMC3096570 DOI: 10.1186/1742-2094-8-34] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 04/14/2011] [Indexed: 01/11/2023] Open
Abstract
Background The transcription factors CCAAT/enhancer binding proteins (C/EBP) α, β and δ have been shown to be expressed in brain and to be involved in regulation of inflammatory genes in concert with nuclear factor κB (NF-κB). In general, C/EBPα is down-regulated, whereas both C/EBPβ and δ are up-regulated in response to inflammatory stimuli. In Alzheimer's disease (AD) one of the hallmarks is chronic neuroinflammation mediated by astrocytes and microglial cells, most likely induced by the formation of amyloid-β (Aβ) deposits. The inflammatory response in AD has been ascribed both beneficial and detrimental roles. It is therefore important to delineate the inflammatory mediators and signaling pathways affected by Aβ deposits with the aim of defining new therapeutic targets. Methods Here we have investigated the effects of Aβ on expression of C/EBP family members with a focus on C/EBPδ in rat primary astro-microglial cultures and in a transgenic mouse model with high levels of fibrillar Aβ deposits (tg-ArcSwe) by western blot analysis. Effects on DNA binding activity were analyzed by electrophoretic mobility shift assay. Cross-talk between C/EBPδ and NF-κB was investigated by analyzing binding to a κB site using a biotin streptavidin-agarose pull-down assay. Results We show that exposure to fibril-enriched, but not oligomer-enriched, preparations of Aβ inhibit up-regulation of C/EBPδ expression in interleukin-1β-activated glial cultures. Furthermore, we observed that, in aged transgenic mice, C/EBPα was significantly down-regulated and C/EBPβ was significantly up-regulated. C/EBPδ, on the other hand, was selectively down-regulated in the forebrain, a part of the brain showing high levels of fibrillar Aβ deposits. In contrast, no difference in expression levels of C/EBPδ between wild type and transgenic mice was detected in the relatively spared hindbrain. Finally, we show that interleukin-1β-induced C/EBPδ DNA binding activity to both C/EBP and κB sites is abolished after exposure to Aβ. Conclusions These data suggest that both expression and function of C/EBPδ are dysregulated in Alzheimer's disease. C/EBPδ seems to be differently regulated in response to different conformations of Aβ. We propose that Aβ induces an imbalance between NF-κB and C/EBP transcription factors that may result in abnormal responses to inflammatory stimuli.
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Affiliation(s)
- Veronica Ramberg
- Department of Neurochemistry, Stockholm University, SE-10691 Stockholm, Sweden
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Tsukada J, Yoshida Y, Kominato Y, Auron PE. The CCAAT/enhancer (C/EBP) family of basic-leucine zipper (bZIP) transcription factors is a multifaceted highly-regulated system for gene regulation. Cytokine 2011; 54:6-19. [DOI: 10.1016/j.cyto.2010.12.019] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2010] [Revised: 12/19/2010] [Accepted: 12/22/2010] [Indexed: 12/18/2022]
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Lingual antimicrobial peptide and IL-8 expression are oppositely regulated by the antagonistic effects of NF-κB p65 and C/EBPβ in mammary epithelial cells. Mol Immunol 2011; 48:895-908. [PMID: 21255844 DOI: 10.1016/j.molimm.2010.12.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Accepted: 12/20/2010] [Indexed: 01/01/2023]
Abstract
Pathogen contact induces quickly in Mammary Epithelial Cells (MEC) the expression of the proinflammatory cytokine IL-8 and delayed that of the bactericidal β-defensin LAP. Both genes encoding these factors feature on their proximal promoter a composite NF-κB/CEBP binding site. We compare here in MEC the role of NF-κB and C/EBP factors in regulating basal and pathogen-induced expression of both genes from cattle. Abrogating NF-κB binding to that site by introduction of a single point mutation blocks promoter activity of both genes in reporter gene assays. Chromatin accessibility PCR and Chromatin immunoprecipitation reveal that the chromatin of the resting LAP promoter is tightly packed and NF-κB p50 homodimer binding prevails. Infection results in chromatin decompaction accompanied by predominant recruitment of NF-κB p65 for promoter activation. Overexpression of transcription factors confirms a stimulatory role of NF-κB p65 but also a repressive function of C/EBPβ for LAP promoter activity. These factors reverse roles to control IL-8 expression. NF-κB p65 homodimers already reside on the resting IL-8 promoter and induction recruits NF-κB p50. Overexpression of both NF-κB factors represses the promoter in MEC, but not in HEK293 cells. Inhibitors of NF-κB activation and nuclear recruitment both tremendously increase basal and pathogen stimulated IL-8 mRNA concentrations in MEC. Mutation of the C/EBP-binding site blocks and overexpression of C/EBPβ stimulates IL-8-promoter activity. Thus, the pathogen-induced fast activation of diverse transcription factors acting through a common promoter binding site is gene specifically differentiated into opposite functional significance for swiftly (IL-8) or slowly (LAP) induced genes in MEC.
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Yockell-Lelièvre J, Spriet C, Cantin P, Malenfant P, Heliot L, de Launoit Y, Audette M. Functional cooperation between Stat-1 and ets-1 to optimize icam-1 gene transcription. Biochem Cell Biol 2010; 87:905-18. [PMID: 19935876 DOI: 10.1139/o09-055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the immune system, enabling the interactions between effector cells and target cells. It is also known to be involved in tumor growth and metastasis. Its expression is transcriptionally regulated by several proinflammatory cytokines including IFN-gamma, which induces ICAM-1 transcription via the JAK-STAT signaling pathway in a Stat1-dependent fashion. The ICAM-1 promoter contains several cis-active regulatory elements including 2 Ets binding sites (EBSs) located at positions -158 and -138 relatively to the AUG, which were previously shown to play a role in the constitutive activity of the ICAM-1 promoter. In the present study, we have determined whether the EBSs are also involved in the regulation of ICAM-1 gene transcription by pro-inflammatory cytokines. Transient transfection assays were performed with reporter genes containing ICAM-1 promoter constructions cloned upstream from the firefly luciferase gene. Site-specific mutations of the EBS diminished the promoter activity stimulated by IFN-gamma, although the IFN-gamma responsive element (pIgammaRE), which binds Stat1, was intact. Stimulation of the transcriptional activity following IFN-gamma treatment was significantly reduced when both EBSs were inactivated. Co-immunoprecipitation experiments provided evidence of a physical interaction involving Ets1 and Stat1. In COS-1 and HEK 293 cells cotransfected with CFP-Stat1 and YFP-Ets fusion protein, fluorescence resonance energy transfer experiments confirmed the close proximity of these 2 proteins in living cells following treatment with IFN-gamma.
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Affiliation(s)
- Julien Yockell-Lelièvre
- Centre de recherche en endocrinologie moléculaire et oncologique, Centre de recherche du CHUQ, Pavillon CHUL, 2705 boulevard Laurier, QC G1V 4G2, Canada
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Hsu MJ, Chang CK, Chen MC, Chen BC, Ma HP, Hong CY, Lin CH. Apoptosis signal-regulating kinase 1 in peptidoglycan-induced COX-2 expression in macrophages. J Leukoc Biol 2010; 87:1069-82. [PMID: 20200402 DOI: 10.1189/jlb.1009668] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
In this study, we investigated the role of ASK1 in PGN-induced C/EBPbeta activation and COX-2 expression in RAW 264.7 macrophages. The PGN-induced COX-2 expression was attenuated by the DNs of ASK1, JNK1, JNK2, a JNK inhibitor (SP600125), and an AP-1 inhibitor (curcumin). PGN caused ASK1 dephosphorylation time-dependently at Ser967, dissociation from the ASK1-14-3-3 complex, and subsequent ASK1 activation. In addition, PGN activated PP2A and suppression of PP2A by okadaic acid markedly inhibited PGN-induced ASK1 Ser967 dephosphorylation and COX-2 expression. PGN induced the activation of the JNK-AP-1 signaling cascade downstream of ASK1. PGN-increased C/EBPbeta expression and DNA-binding activity were inhibited by the ASK1-JNK-AP-1 signaling blockade. COX-2 promoter luciferase activity induced by PGN was attenuated in cells transfected with the COX-2 reporter construct possessing the C/EBP-binding site mutation. In addition, the ASK1-JNK-AP-1-C/EBPbeta cascade was activated in human peripheral mononuclear cells exposure to PGN. The TLR2 agonist Pam(3)CSK(4) was also shown to induce ASK1 Ser967 dephosphorylation, JNK and c-jun phosphorylation, C/EBPbeta activation, and COX-2 expression in RAW 264.7 macrophages. PGN-induced COX-2 promoter luciferase activity was prevented by selective inhibition of TLR2 and c-Jun in RAW 264.7 macrophages. Our data demonstrate that PGN might activate the TLR2-mediated PP2A-ASK1-JNK-AP-1-C/EBPbeta cascade and subsequent COX-2 expression in RAW 264.7 macrophages.
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Affiliation(s)
- Ming-Jen Hsu
- Graduate Institute of Medical Sciences, Department of Pharmacology, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan
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Cromer D, Stark J, Christophides G. Hidden variable analysis of transcription factor cooperativity from microarray time courses. IET Syst Biol 2010; 4:131-44. [DOI: 10.1049/iet-syb.2009.0012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Lee SH, Krisanapun C, Baek SJ. NSAID-activated gene-1 as a molecular target for capsaicin-induced apoptosis through a novel molecular mechanism involving GSK3beta, C/EBPbeta and ATF3. Carcinogenesis 2010; 31:719-28. [PMID: 20110283 DOI: 10.1093/carcin/bgq016] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Capsaicin, a natural product of the Capsicum species of red peppers, is known to induce apoptosis and suppress growth. Non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1) is a cytokine associated with pro-apoptotic and antitumorigenic property in colorectal and lung cancer. Our data demonstrate that capsaicin leads to induction of apoptosis and up-regulates NAG-1 gene expression at the transcriptional level. Overexpression of CCAAT/enhancer binding protein beta (C/EBPbeta) caused a significant increase of basal and capsaicin-induced NAG-1 promoter activity. We subsequently identified C/EBPbeta binding sites in the NAG-1 promoter responsible for capsaicin-induced NAG-1 transactivation. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay confirmed binding of C/EBPbeta to the NAG-1 promoter. Capsaicin treatment resulted in an increase of phosphorylated serine/threonine residues on C/EBPbeta, and the immunoprecipitation study showed that capsaicin enhanced binding of C/EBPbeta with glycogen synthase kinase 3beta (GSK3beta) and activating transcription factor 3 (ATF3). The phosphorylation and interaction of C/EBPbeta with GSK3beta and ATF3 are decreased by the inhibition of the GSK3beta and Protein Kinase C pathways. Knockdown of C/EBPbeta, GSK3beta or ATF3 ameliorates NAG-1 expression induced by capsaicin treatment. These data indicate that C/EBPbeta phosphorylation through GSK3beta may mediate capsaicin-induced expression of NAG-1 and apoptosis through cooperation with ATF3 in human colorectal cancer cells.
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Affiliation(s)
- Seong-Ho Lee
- Laboratory of Environmental Carcinogenesis, Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37996, USA
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Sow FB, Alvarez GR, Gross RP, Satoskar AR, Schlesinger LS, Zwilling BS, Lafuse WP. Role of STAT1, NF-kappaB, and C/EBPbeta in the macrophage transcriptional regulation of hepcidin by mycobacterial infection and IFN-gamma. J Leukoc Biol 2009; 86:1247-58. [PMID: 19652026 DOI: 10.1189/jlb.1208719] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Hepcidin is an antimicrobial peptide involved in regulating iron homeostasis. It is induced by iron overload and decreased by hypoxia and anemia. Hepcidin regulates iron metabolism by inhibiting iron absorption by the duodenum and by inhibiting macrophage iron recycling. Hepcidin is induced in hepatocytes during the acute-phase response by IL-6. Previously, we have shown that hepcidin is not induced in macrophages by IL-6 but is induced by the synergistic interaction of IFN-gamma and Mycobacterium tuberculosis infection. In the present study, we examined the pathways involved in inducing macrophage hepcidin expression. We show that TLRs TLR2 and TLR4 and the transcription factor STAT1 are required for induction of hepcidin mRNA. Hepcidin promoter activity is also synergistically induced in RAW264.7 macrophages by IFN-gamma and M. tuberculosis. NF-kappaB and C/CEBP binding sites are required for promoter activity. Binding of NF-kappaB (p50/p65) to the NF-kappaB site and STAT1 and C/EBPbeta to the C/CEBP site was confirmed by EMSA. Knockdown of STAT1 and C/EBPbeta expression in RAW264.7 cells with siRNA plasmids inhibited hepcidin promoter activity induced by IFN-gamma and M. tuberculosis. Together, these studies demonstrate that macrophage hepcidin expression is induced by the activation of STAT1 and NF-kappaB and the induction of C/EBPbeta expression.
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Affiliation(s)
- Fatoumata B Sow
- Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
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31
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Chae JJ, Aksentijevich I, Kastner DL. Advances in the understanding of familial Mediterranean fever and possibilities for targeted therapy. Br J Haematol 2009; 146:467-78. [PMID: 19466978 DOI: 10.1111/j.1365-2141.2009.07733.x] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder characterized by seemingly unprovoked recurrent episodes of fever and serosal, synovial, or cutaneous inflammation. FMF is caused by recessively inherited mutations in MEFV, which encodes pyrin, and most of the mutations are present in the C-terminal end of the protein encoding B30.2 domain. The FMF carrier frequencies are extremely high in several eastern Mediterranean populations. Pyrin is expressed in granulocytes, monocytes, dendritic cells, and synovial fibroblasts. Pyrin regulates caspase-1 activation and consequently interleukin-1beta production through the interactions of its N-terminal PYRIN domain and C-terminal B30.2 domain with an adaptor protein, apoptosis-associated speck-like protein with a caspase-recruitment domain (ASC) and caspase-1 respectively. Pyrin is cleaved by caspase-1 and the cleaved N-terminal fragment translocates to nucleus and enhances ASC-independent nuclear factor (NF)-kappaB activation through interactions with p65 NF-kappaB and IkappaB-alpha. In addition to the regulatory role of pyrin for caspase-1, the cleavage of pyrin provides an important clue not only in understanding the molecular pathogenesis of FMF but also in developing new therapeutic targets for FMF.
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Affiliation(s)
- Jae J Chae
- Laboratory of Clinical Investigation, National Institutes of Arthritis and Musculoskeletal and Skin Diseases, Genetics and Genomics Branch, Bethesda, MD 20892-1849, USA.
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Hayashida M, Okazaki K, Fukushi J, Sakamoto A, Iwamoto Y. CCAAT/enhancer binding protein beta mediates expression of matrix metalloproteinase 13 in human articular chondrocytes in inflammatory arthritis. ACTA ACUST UNITED AC 2009; 60:708-16. [PMID: 19248099 DOI: 10.1002/art.24332] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To determine the function of CCAAT/enhancer binding protein beta (C/EBPbeta) in the expression of matrix metalloproteinase 13 (MMP-13) in chondrocytes in inflammatory arthritis. METHODS Cartilage obtained from patients with rheumatoid arthritis and osteoarthritis was immunostained for expression of C/EBPbeta or MMP-13. Interleukin-1beta- or tumor necrosis factor alpha (TNFalpha)-stimulated chondrocytes were subjected to Western blotting and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). MMP-13 promoter assays were conducted, and the C/EBPbeta response element was characterized by deletion and mutation analysis. C-28/I2 cells were treated with TNFalpha and subjected to chromatin immunoprecipitation (ChIP) assays. Finally, C/EBPbeta-liver-enriched activator protein (LAP) was overexpressed in C-28/I2 cells or cartilage tissues, and MMP-13 expression was analyzed. RESULTS C/EBPbeta and MMP-13 expression was colocalized in chondrocytes in arthritic cartilage. MMP-13 promoter activity was stimulated by C/EBPbeta overexpression in a dose-dependent manner. Luciferase assays revealed that a -981-bp promoter had the greatest activity, while deletion to -936 bp strongly diminished promoter activity. Luciferase activity was repressed to basal levels by mutations in potential C/EBP binding sites. The stimulatory effects of C/EBPbeta overexpression were diminished by mutation. ChIP assays revealed that TNFalpha treatment enhanced the binding of C/EBPbeta to the MMP-13 promoter. When C/EBPbeta-LAP was overexpressed in C-28/I2 cells, endogenous MMP-13 expression was stimulated up to 32-fold as detected by real-time RT-PCR. Furthermore, following adenoviral overexpression of C/EBPbeta-LAP in organ culture of articular cartilage, stimulation of MMP-13 was also detected by immunohistochemistry. CONCLUSION C/EBPbeta directly binds to the MMP-13 promoter region and stimulates the expression of MMP-13 in chondrocytes in inflammatory arthritis.
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Qiu X, Aiken KJ, Chokas AL, Beachy DE, Nick HS. Distinct functions of CCAAT enhancer-binding protein isoforms in the regulation of manganese superoxide dismutase during interleukin-1beta stimulation. J Biol Chem 2008; 283:25774-85. [PMID: 18559338 PMCID: PMC2533776 DOI: 10.1074/jbc.m801178200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 06/03/2008] [Indexed: 01/29/2023] Open
Abstract
The mitochondrial antioxidant enzyme manganese superoxide dismutase (Mn-SOD) is crucial in maintaining cellular and organismal homeostasis. Mn-SOD expression is tightly regulated in a manner that synchronizes its cytoprotective functions during inflammatory challenges. Induction of Mn-SOD gene expression by the proinflammatory cytokine IL-1beta is mediated through a complex intronic enhancer element. To identify and characterize the transcription factors required for Mn-SOD enhancer function, a yeast one-hybrid assay was utilized, and two CCAAT enhancer-binding protein (C/EBP) members, C/EBP beta and C/EBP delta, were identified. These two transcription factors responded to IL-1beta treatment with distinct expression profiles, different temporal yet inducible interactions with the endogenous Mn-SOD enhancer, and also opposite effects on Mn-SOD transcription. C/EBP beta is expressed as three isoforms, LAP* (liver-activating protein), LAP, and LIP (liver-inhibitory protein). Our functional analysis demonstrated that only the full-length C/EBP beta/LAP* served as a true activator for Mn-SOD, whereas LAP, LIP, and C/EBP delta functioned as potential repressors. Finally, our systematic mutagenesis of the unique N-terminal 21 amino acids further solidified the importance of LAP* in the induction of Mn-SOD and emphasized the crucial role of this isoform. Our data demonstrating the physiological relevance of the N-terminal peptide also provide a rationale for revisiting the role of LAP* in the regulation of other genes and in pathways such as lipogenesis and development.
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Affiliation(s)
- Xiaolei Qiu
- Department of Neuroscience,
McKnight Brian Institute, and
Department of Biochemistry and Molecular
Biology, University of Florida, Gainesville, Florida 32610
| | - Kimberly J. Aiken
- Department of Neuroscience,
McKnight Brian Institute, and
Department of Biochemistry and Molecular
Biology, University of Florida, Gainesville, Florida 32610
| | - Ann L. Chokas
- Department of Neuroscience,
McKnight Brian Institute, and
Department of Biochemistry and Molecular
Biology, University of Florida, Gainesville, Florida 32610
| | - Dawn E. Beachy
- Department of Neuroscience,
McKnight Brian Institute, and
Department of Biochemistry and Molecular
Biology, University of Florida, Gainesville, Florida 32610
| | - Harry S. Nick
- Department of Neuroscience,
McKnight Brian Institute, and
Department of Biochemistry and Molecular
Biology, University of Florida, Gainesville, Florida 32610
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Matsuo S, Yamazaki S, Takeshige K, Muta T. Crucial roles of binding sites for NF-kappaB and C/EBPs in IkappaB-zeta-mediated transcriptional activation. Biochem J 2007; 405:605-15. [PMID: 17447895 PMCID: PMC2267307 DOI: 10.1042/bj20061797] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
IkappaB-zeta [inhibitor of NF-kappaB (nuclear factor kappaB) zeta] is a nuclear protein that is induced upon stimulation of TLRs (Toll-like receptors) and IL (interleukin)-1 receptor. IkappaB-zeta harbours C-terminal ankyrin repeats that interact with NF-kappaB. Our recent studies have shown that, upon stimulation, IkappaB-zeta is essential for the induction of a subset of inflammatory genes, represented by IL-6, whereas it inhibits the expression of TNF (tumour necrosis factor)-alpha. In the present study, we investigated mechanisms that determine the different functions of IkappaB-zeta. We found that co-expression of IkappaB-zeta and the NF-kappaB subunits synergistically activates transcription of the hBD-2 (human beta-defensin 2) and NGAL (neutrophil gelatinase-associated lipocalin) genes, whereas it inhibits transcription of E-selectin. Reporter analyses indicated that, in addition to an NF-kappaB-binding site, a flanking C/EBP (CCAAT/enhancer-binding protein)-binding site in the promoters is essential for the IkappaB-zeta-mediated transcriptional activation. Using an artificial promoter consisting of the NF-kappaB- and C/EBP-binding sites, transcriptional activation was observed upon co-transfection with IkappaB-zeta and NF-kappaB, indicating that these sequences are minimal elements that confer the IkappaB-zeta-mediated transcriptional activation. Chromatin immunoprecipitation assays and knockdown experiments showed that both IkappaB-zeta and the NF-kappaB subunits were recruited to the NGAL promoter and were essential for the transcriptional activation of the hBD-2 and NGAL promoters on stimulation with IL-1beta. The activation of the NGAL promoter by transfection of IkappaB-zeta and NF-kappaB was suppressed in C/EBPbeta-depleted cells. Thus IkappaB-zeta acts as an essential transcriptional activator by forming a complex with NF-kappaB on promoters harbouring the NF-kappaB- and C/EBP-binding sites, upon stimulation of TLRs or IL-1 receptor.
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Affiliation(s)
- Susumu Matsuo
- *Department of Molecular and Cellular Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Soh Yamazaki
- *Department of Molecular and Cellular Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Koichiro Takeshige
- *Department of Molecular and Cellular Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tatsushi Muta
- *Department of Molecular and Cellular Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- †Laboratory of Cell Recognition and Responses, Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Japan
- To whom correspondence should be addressed (email )
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Soloff MS, Izban MG, Cook DL, Jeng YJ, Mifflin RC. Interleukin-1-induced NF-κB recruitment to the oxytocin receptor gene inhibits RNA polymerase II–promoter interactions in cultured human myometrial cells. ACTA ACUST UNITED AC 2006; 12:619-24. [PMID: 16888077 DOI: 10.1093/molehr/gal067] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The myometrial oxytocin receptor (OTR) is highly regulated during pregnancy, reaching maximal concentrations near term. These levels are then abruptly reduced in advanced labour and the post-partum period. Our goal was to examine the molecular basis for this reduction, using chromatin immunoprecipitation (ChIP). Interleukin-1alpha (IL1A) treatment of cultured human myometrial cells has previously been shown to reduce steady-state levels of OTR mRNA. We show further that IL1A reduced RNA polymerase II cross-linking to the otr promoter, as reflective of transcriptional inhibition. IL1A also increased the recruitment of nuclear factor kappaB (NF-kappaB) to a site 955 bp upstream from the transcriptional start site. Inhibition of NF-kappaB activation negated the effects of IL1A on polymerase II dissociation, indicating a causal relationship, at least in part, between recruitment of NF-kappaB and detachment of polymerase from the otherwise constitutively active otr promoter. IL1A treatment also resulted in increased histone H4 acetylation in the otr promoter region. Whereas NF-kappaB recruitment and histone acetylation are generally associated with activation of gene expression, our findings show that both processes can be involved in dissociation of RNA polymerase II from an active promoter. The results of these studies suggest that the elevation of IL1 in the myometrium occurring at the end of pregnancy initiates the process of down-regulation of OTRs in advanced labour, resulting in the desensitization of the myometrium to elevated levels of OT in the blood during lactation.
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Affiliation(s)
- Melvyn S Soloff
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX 77555-1062, USA.
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36
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Meredith JM, Munks RJL, Grail W, Hurd H, Eggleston P, Lehane MJ. A novel association between clustered NF-kappaB and C/EBP binding sites is required for immune regulation of mosquito Defensin genes. INSECT MOLECULAR BIOLOGY 2006; 15:393-401. [PMID: 16907826 PMCID: PMC1602061 DOI: 10.1111/j.1365-2583.2006.00635.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A comparative analysis identified key cis-acting regulatory elements responsible for the temporal control of mosquito Defensin gene expression. The promoters of Anopheles gambiae Defensin 1 and two isoforms of Aedes aegypti Defensin A are up-regulated by immune challenge. This stimulated activity depends upon a cluster of three NF-kappaB binding sites and closely associated C/EBP-like motifs, which function as a unit for optimal promoter activity. Binding of NF-kappaB and C/EBP like transcription factors is confirmed by electrophoretic mobility shift assay, including supershifts with antibodies to C/EBP. KappaB-like motifs are abundant within antimicrobial peptide gene promoters and most are very closely associated with putative C/EBP binding sites. This novel association between NF-kappaB and C/EBP binding sites may, therefore, be of widespread significance.
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Affiliation(s)
- J M Meredith
- School of Life Sciences, Huxley Building, Keele University, Staffordshire, UK.
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37
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Chiang BT, Liu YW, Chen BK, Wang JM, Chang WC. Direct interaction of C/EBPdelta and Sp1 at the GC-enriched promoter region synergizes the IL-10 gene transcription in mouse macrophage. J Biomed Sci 2006; 13:621-35. [PMID: 16871431 DOI: 10.1007/s11373-006-9101-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 06/12/2006] [Indexed: 11/27/2022] Open
Abstract
We previously reported that LPS activates the transcription of the IL-10 gene through the Sp1 and C/EBP binding sites and indicated that Sp1, C/EBPbeta and C/EBPdelta can coactivate the IL-10 gene expression in mouse macrophage cells [Liu Y.-W., Tseng H.-P., Chen L.-C., Chen B.-K., Chang W.-C. J. Immunol. 171: 821-828, 2003]. In the present report, we demonstrated the direct physical interaction between C/EBPdelta and Sp1, and also mapped the interaction domains of these two proteins. C/EBPdelta binds to Sp1 via its basic region leucine zipper domain. The C-terminus of Sp1 was also the major region interacting with C/EBPdelta. However, both glutamine- and serine/threonine-rich homologus regions of Sp1 also interacted with C/EBPdelta. The binding of Sp1 and C/EBPdelta as a complex to the Sp1 binding site on the promoter of IL-10 was further confirmed by using the DNA affinity precipitation assay. By using Sp1-deficient SL2 cells, we also found that the overexpressions of C/EBPdelta and Sp1 synergically activate the transcriptional activity of IL-10 gene. Taken together, our present results revealed a novel mechanism of a superactivation of Sp1 by C/EBPdelta via a direct interaction between these two transcription factors leading to the activation of the IL-10 gene in mouse macrophage cells.
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Affiliation(s)
- Ben-Tzu Chiang
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
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38
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Borger P, Tamm M, Black JL, Roth M. Asthma: is it due to an abnormal airway smooth muscle cell? Am J Respir Crit Care Med 2006; 174:367-72. [PMID: 16690983 DOI: 10.1164/rccm.200501-082pp] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Asthma is an airway disease highly prevalent in westernized countries and of unknown etiology. Often, asthma is associated with atopy, but not all atopic individuals have asthma. Some patients with asthma outgrow symptoms, whereas many others acquire asthma later in life. Still other patients suffer from asthma their entire life. How can we explain these different patterns? It may be that asthma should be regarded as the clinical manifestation of a group of diseases with similar pathology due to a common factor. In this Pulmonary Perspective, we propose that an aberrant phenotype of airway smooth muscle (ASM) cells could be sufficient to explain the pathology of asthma. We will argue an abnormal ASM cell is a prerequisite to the development of asthma. Our postulate is that inadequate levels of C/EBPalpha, a protein that is pivotal for the suppression of both inflammation and proliferation responses, confer on ASM cells an activated phenotype that is more susceptible to mitogenic and contractile stimuli.
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Affiliation(s)
- Peter Borger
- Pulmonary Cell Research Department of Research University of Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
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39
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King JE, Eugenin EA, Buckner CM, Berman JW. HIV tat and neurotoxicity. Microbes Infect 2006; 8:1347-57. [PMID: 16697675 DOI: 10.1016/j.micinf.2005.11.014] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 11/29/2005] [Indexed: 01/13/2023]
Abstract
HIV tat is the transactivator of HIV-1, supporting efficient viral replication by stabilizing the transcription of viral genes. Tat can be released from HIV-infected cells and alter several functions in uninfected cells. In the brain, tat induces neuronal dysfunction/toxicity, even though neurons cannot be directly infected with HIV, resulting in CNS pathology, such as the dementia and encephalitis associated with NeuroAIDS. This review discusses the most recent data addressing tat-induced neurotoxicity and integrates these new findings in the context of NeuroAIDS.
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Affiliation(s)
- J E King
- Department of Pathology, F727, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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40
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Ralph WM, Liu K, Auborn KJ. CCAAT/enhancer-binding protein beta represses human papillomavirus 11 upstream regulatory region expression through a promoter-proximal YY1-binding site. J Gen Virol 2006; 87:51-59. [PMID: 16361417 DOI: 10.1099/vir.0.81207-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
CCAAT/enhancer-binding protein beta (C/EBPbeta) can function as a repressor or as an activator of human papillomavirus (HPV) gene expression, depending on which cell type the experiments are conducted. In this report, it was shown that within primary human foreskin keratinocyte cells (HFK) the activity of C/EBPbeta can be switched from that of a repressor of HPV11 expression to an activator by mutating a single promoter-proximal consensus YY1-binding site within the HPV11 upstream regulatory region (URR). It was shown that in HFK cells, exogenous expression of C/EBPbeta significantly activates the expression of mutant HPV11 URR reporter plasmids that contain deletions which overlap a 127 bp region (-269 to -142). Inclusive in this region are binding sites for multiple transcription factors, including AP1, YY1 and C/EBPalpha. Only mutation of the YY1 site resulted in the switch in phenotype, indicating that C/EBPbeta represses HPV11 expression in these cells via YY1 binding. The level of YY1 activity was also measured in HFK cells transfected with a C/EBPbeta expression plasmid and a significant increase in YY1 activity as compared with mock-transfected cells was found. C33A cells, which exhibit activation of wild-type HPV11 gene expression with exogenous C/EBPbeta co-expression, failed to demonstrate C/EBPbeta-induced YY1 activation. It was concluded that in HFK cells, exogenous C/EBPbeta induces the activity of YY1, which, in turn, can repress HPV11 URR expression through the promoter-proximal YY1-binding site.
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Affiliation(s)
- Walter M Ralph
- Northshore-Long Island Jewish Research Institute, 350 Community Drive, Manhasset, NY 11030, USA
| | - Kai Liu
- Northshore-Long Island Jewish Research Institute, 350 Community Drive, Manhasset, NY 11030, USA
| | - Karen J Auborn
- Department of Otolaryngology, Long Island Jewish Medical Center, Long Island Campus of Albert Einstein College of Medicine, New Hyde Park, NY 11040, USA
- Northshore-Long Island Jewish Research Institute, 350 Community Drive, Manhasset, NY 11030, USA
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41
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Kalvakolanu DV, Roy SK. CCAAT/enhancer binding proteins and interferon signaling pathways. J Interferon Cytokine Res 2006; 25:757-69. [PMID: 16375604 DOI: 10.1089/jir.2005.25.757] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interferons (IFNs) regulate a number of host responses, including innate and adaptive immunity against viruses, microbes, and neoplastic cells. These responses are dependent on the expression of IFN-stimulated genes (ISGs). Given the diversities in these responses and their kinetics, it is conceivable that a number of different factors are required for controlling them. Here, we describe one such pathway wherein transcription factor CAAAT/enhancer binding protein-beta (C/EBP-beta) is controlled via IFN-gamma-induced MAPK signaling pathways. At least two IFN-gamma-induced MAPK signals converge on to C/EBP-beta for inducing transcription. One of these, driven by extracellular signal-regulated kinases (ERKs), phosphorylates the C/EBP-beta protein in its regulatory domain. The second, driven by the mixed-lineage kinases (MLKs), induces a dephosphorylation leading to the recruitment of transcriptional coactivators.
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Affiliation(s)
- Dhananjaya V Kalvakolanu
- Greenebaum Cancer Center, Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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42
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Paz-Priel I, Cai DH, Wang D, Kowalski J, Blackford A, Liu H, Heckman CA, Gombart AF, Koeffler HP, Boxer LM, Friedman AD. CCAAT/enhancer binding protein alpha (C/EBPalpha) and C/EBPalpha myeloid oncoproteins induce bcl-2 via interaction of their basic regions with nuclear factor-kappaB p50. Mol Cancer Res 2006; 3:585-96. [PMID: 16254192 DOI: 10.1158/1541-7786.mcr-05-0111] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The CEBPA gene is mutated in 10% of acute myeloid leukemia (AML) cases. We find that CEBPA and Bcl-2 RNA levels correlate highly in low-risk human AMLs, suggesting that inhibition of apoptosis via induction of bcl-2 by CCAAT/enhancer binding protein alpha (C/EBPalpha) or its mutant variants contributes to transformation. C/EBPalphap30, lacking a NH2-terminal transactivation domain, or C/EBPalphaLZ, carrying in-frame mutations in the leucine zipper that prevent DNA binding, induced bcl-2 in hematopoietic cell lines, and C/EBPalpha induced bcl-2 in normal murine myeloid progenitors and in the splenocytes of H2K-C/EBPalpha-Emu transgenic mice. C/EBPalpha protected Ba/F3 cells from apoptosis on interleukin-3 withdrawal but not if bcl-2 was knocked down. Remarkably, C/EBPalphaLZ oncoproteins activated the bcl-2 P2 promoter despite lack of DNA binding, and C/EBPalphap30 also activated the promoter. C/EBPalpha and the C/EBPalpha oncoproteins cooperated with nuclear factor-kappaB (NF-kappaB) p50, but not p65, to induce bcl-2 transcription. Endogenous C/EBPalpha preferentially coimmunoprecipitated with p50 versus p65 in myeloid cell extracts. Mutation of residues 297 to 302 in the C/EBPalpha basic region prevented induction of endogenous bcl-2 or the bcl-2 promoter and interaction with p50 but not p65. These findings suggest that C/EBPalpha or its mutant variants tether to a subset of NF-kappaB target genes, including Bcl-2, via p50 to facilitate gene activation and offer an explanation for preferential in-frame rather than out-of-frame mutation of the leucine zipper with sparing of the basic region in C/EBPalphaLZ oncoproteins. Targeting interaction between C/EBPalpha basic region and NF-kappaB p50 may contribute to the therapy of AML and other malignancies expressing C/EBPs.
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MESH Headings
- Adult
- Animals
- Apoptosis/physiology
- CCAAT-Enhancer-Binding Protein-alpha/genetics
- CCAAT-Enhancer-Binding Protein-alpha/metabolism
- Cell Line
- HL-60 Cells
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/metabolism
- Humans
- Leukemia, Myeloid, Acute/enzymology
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Transgenic
- NF-kappa B p50 Subunit/metabolism
- Oncogene Proteins/genetics
- Oncogene Proteins/metabolism
- Promoter Regions, Genetic
- Proto-Oncogene Proteins c-bcl-2/biosynthesis
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Rats
- Transcriptional Activation
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Affiliation(s)
- Ido Paz-Priel
- Division of Pediatric Oncology, Johns Hopkins University, CRB 253, 1650 Orleans Street, Baltimore, Maryland 21231, USA
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43
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Okawa T, Naomoto Y, Nobuhisa T, Takaoka M, Motoki T, Shirakawa Y, Yamatsuji T, Inoue H, Ouchida M, Gunduz M, Nakajima M, Tanaka N. Heparanase Is Involved in Angiogenesis in Esophageal Cancer through Induction of Cyclooxygenase-2. Clin Cancer Res 2005; 11:7995-8005. [PMID: 16299228 DOI: 10.1158/1078-0432.ccr-05-1103] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Both heparanase and cyclooxygenase-2 (COX-2) are thought to play critical roles for tumor malignancy, including angiogenesis, although it is unknown about their relationship with each other in cancer progression. We hypothesized that they may link to each other on tumor angiogenesis. EXPERIMENTAL DESIGN The expressions of heparanase and COX-2 in 77 primary human esophageal cancer tissues were assessed by immunohistochemistry to do statistical analysis for the correlation between their clinicopathologic features, microvessel density, and survival of those clinical cases. Human esophageal cancer cells were transduced with heparanase cDNA and used for reverse transcription-PCR and Western blot to determine the expression of heparanase and COX-2. COX-2 promoter vector and its deletion/mutation constructs were also used along with transduction of heparanase cDNA for luciferase assay. RESULTS Heparanase and COX-2 protein expression exhibited a similar pattern in esophageal tumor tissues, and their expression correlated with tumor malignancy and poor survival. Their expression also revealed a significant correlation with high intratumoral microvessel density. Up-regulation of COX-2 mRNA and protein was observed in esophageal cancer cells transfected with heparanase cDNA. COX-2 promoter was activated after heparanase cDNA was transduced and the deletion/mutation of three transcription factor (cyclic AMP response element, nuclear factor-kappaB, and nuclear factor-interleukin-6) binding elements in COX-2 promoter strongly suppressed its activity. CONCLUSION Our results suggest that heparanase may play a novel role for COX-2-mediated tumor angiogenesis.
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Affiliation(s)
- Takaomi Okawa
- Department of Gastroenterological Surgery, Transplant, and Surgical Oncology, Okayama University, Okayama, Japan
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Voleti B, Agrawal A. Regulation of basal and induced expression of C-reactive protein through an overlapping element for OCT-1 and NF-kappaB on the proximal promoter. THE JOURNAL OF IMMUNOLOGY 2005; 175:3386-90. [PMID: 16116232 PMCID: PMC3818712 DOI: 10.4049/jimmunol.175.5.3386] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
C-reactive protein (CRP) is an acute phase protein produced by hepatocytes. A minor elevation in the baseline levels of serum CRP is considered an indicator of chronic inflammation. In hepatoma Hep3B cells, IL-6 induces CRP expression by activating transcription factors STAT3 and C/EBPbeta. IL-1 synergistically enhances the effects of IL-6. The first 157 bp of the CRP promoter are sufficient for IL-1 synergy. Previously, NF-kappaB, a transcription factor activated by IL-1beta in Hep3B cells, has been shown to increase endogenous CRP expression. The purpose of this study was to investigate the possible action of NF-kappaB on the 157 bp of the proximal promoter. In this study we show that NF-kappaB requires and acts synergistically with C/EBPbeta on the CRP-proximal promoter to regulate CRP expression. We located the regulatory element that consisted of overlapping binding sites for NF-kappaB (p50-p50 and p50-p65) and OCT-1. The kappaB site was responsible for the synergy between NF-kappaB and C/EBPbeta and was also necessary for the CRP transactivation by C/EBPbeta through the C/EBP site. Mutation of the kappaB site decreased the synergistic effect of IL-1beta on IL-6-induced CRP expression. Basal CRP expression increased dramatically when binding of both OCT-1 and NF-kappaB was abolished. Combined data from luciferase transactivation assays and EMSA lead us to conclude that the binding of OCT-1 to the promoter, facilitated by p50-p50 in a novel way, represses, whereas replacement of OCT-1 by p50-p65 induces CRP transcription in cooperation with C/EBPbeta. This model for CRP expression favors the variation seen in baseline serum CRP levels in a normal healthy population.
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Affiliation(s)
| | - Alok Agrawal
- Address correspondence and reprint requests to Dr. Alok Agrawal, Department of Pharmacology, P.O. Box 70577, East Tennessee State University, Johnson City, TN 37614.
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Moxley RA, Jarrett HW. Oligonucleotide trapping method for transcription factor purification systematic optimization using electrophoretic mobility shift assay. J Chromatogr A 2005; 1070:23-34. [PMID: 15861784 DOI: 10.1016/j.chroma.2005.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Oligonucleotide trapping, where a transcription factor-DNA response element complex is formed in solution and then recovered (trapped) on a column, was optimized for the purification of CAAT/enhancer binding protein (C/EBP) from rat liver nuclear extract. Electrophoretic mobility shift assays (EMSAs) with ACEP24(GT)5 oligonucleotide, containing the CAAT element, was used to estimate thebinding affinity and concentration of C/EBP in the nuclear extract and then low concentrations of protein and oligonucleotide, which favor specific binding, were used for all further experiments. Also using EMSA, the highest concentrations of competitors, which inhibit non-specific binding but do not inhibit oligonucleotide binding by C/EBP, were determined to be 932 nM T18 (single-stranded DNA), 50 ng/ml heparin (non-DNA competitor), and 50 microg/ml poly(dI:dC) (duplex DNA). Inclusion of 0.1% Tween-20 improved DNA binding. For complex formation, 110 microg nuclear extract was diluted to 0.2 nM C/EBP (apparent Kd of C/EBP) and 1.34 nM ACEP24(GT)5 was added, along with Tween-20 and the competitors. After incubation, the complex was trapped by annealing the (GT)5 tail of the C/EBP-[ACEP24(GT)5] complex to an (AC)5-Sepharose column under flow at 4 degrees C. The column was washed with 0.4 M NaCl and the protein eluted with 1.2 M NaCl. The purification typically resulted in two proteins of apparent molecular mass 32000 and 38000. The smaller one, the major product, was identified to be C/EBP-alpha. The yield was 2.1 microg (66 pmol) of purified C/EBP-alpha p32. This systematic approach to oligonucleotide trapping is generally applicable for the purification of other transcription factors.
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Affiliation(s)
- Robert A Moxley
- Department of Molecular Sciences, University of Tennessee, 858 Madison Avenue, Suite G-01, Molecular Sciences Building, Memphis, TN 38163, USA
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Du Y, Chen X, Wei X, Bales KR, Berg DT, Paul SM, Farlow MR, Maloney B, Ge YW, Lahiri DK. NF-(kappa)B mediates amyloid beta peptide-stimulated activity of the human apolipoprotein E gene promoter in human astroglial cells. ACTA ACUST UNITED AC 2005; 136:177-88. [PMID: 15893602 DOI: 10.1016/j.molbrainres.2005.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Revised: 01/24/2005] [Accepted: 02/03/2005] [Indexed: 01/04/2023]
Abstract
The apolipoprotein E gene (APOE) plays an important role in the pathogenesis of Alzheimer's disease (AD), and amyloid plaque comprised mostly of the amyloid-beta peptide (A(beta)) is one of the major hallmarks of AD. However, the relationship between these two important molecules is poorly understood. We examined how A(beta) treatment affects APOE expression in cultured cells and tested the role of the transcription factor NF-(kappa)B in APOE gene regulation. To delineate NF-(kappa)B's role, we have characterized a 1098 nucleotide (nt) segment containing the 5'-flanking region of the human APOE gene (-1054/+44, +1 transcription start site). Sequence analysis of this region suggests the presence of two potential NF-(kappa)B elements. To demonstrate promoter activity, the region was cloned upstream of a promoterless luciferase (reporter) gene. This segment was able to drive expression of luciferase in transient transfections of human fetal glial cells. Promoter activity was stimulated twofold by A(beta)(1-40) (25 microM, 24 h) treatment. Pretreatment with double-stranded DNA decoy oligonucleotides against NF-(kappa)B (2 microM) reduced A(beta) stimulation. Deletion and mutagenetic analyses demonstrated that the distal NF-(kappa)B element was functional and showed a strong DNA-protein complex band in gel shift analysis, similar to that from control NF-(kappa)B consensus element. An anti-inflammatory and anti-NF-(kappa)B drug, sodium salicylate, significantly blocked A(beta)-induced APOE promoter function. Our data provide evidence that upregulation of APOE by A(beta) in astroglial cells is mediated by an NF-(kappa)B-element present in the 5'-flanking region of the APOE gene.
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Affiliation(s)
- Yansheng Du
- Department of Neurology, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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47
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Göransson M, Elias E, Ståhlberg A, Olofsson A, Andersson C, Aman P. Myxoid liposarcoma FUS-DDIT3 fusion oncogene induces C/EBP beta-mediated interleukin 6 expression. Int J Cancer 2005; 115:556-60. [PMID: 15688424 DOI: 10.1002/ijc.20893] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The myxoid/round cell liposarcoma oncogene FUS-DDIT3 is the result of a translocation derived gene fusion between the splicing factor FUS and DDIT3. In order to investigate the downstream targets of DDIT3, and the transforming effects of the FUS-DDIT3 fusion protein, we have introduced DDIT3-GFP and FUS-DDIT3-GFP constructs into a human fibrosarcoma cell line. The gene expression profiles of stable transfectants were compared to the original fibrosarcoma cell line by microarray analysis. We here report that the NFkappaB and C/EBP beta controlled gene IL6 is upregulated in DDIT3- and FUS-DDIT3-expressing fibrosarcoma cell lines and in myxoid liposarcoma cell lines. Strong expression of the tumor associated multifunctional cytokine interleukin 6 was confirmed both at mRNA and protein level. Knockdown experiments using siRNA against CEBPB transcripts showed that the effect of FUS-DDIT3 on IL6 expression is C/EBP beta dependent. Chromatin immunoprecipitation revealed direct interaction between the IL6 promoter and the C/EBP beta protein. In addition, the effect of DDIT3 and FUS-DDIT3 on the expression of other acute phase genes was examined using real-time PCR. We demonstrate for the first time that DDIT3 and FUS-DDIT3 show opposite transcriptional regulation of IL8 and suggest that FUS-DDIT3 may affect the synergistic activation of promoters regulated by C/EBP beta and NFkappaB.
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Affiliation(s)
- Melker Göransson
- Lundberg Laboratory for Cancer Research (LLCR), Department of Pathology, Goteborg University, Gothenburg, Sweden.
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Sankpal NV, Mayo MW, Powell SM. Transcriptional repression of TFF1 in gastric epithelial cells by CCAAT/enhancer binding protein-beta. ACTA ACUST UNITED AC 2005; 1728:1-10. [PMID: 15777639 DOI: 10.1016/j.bbaexp.2004.12.014] [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] [Received: 10/13/2004] [Revised: 12/13/2004] [Accepted: 12/16/2004] [Indexed: 01/08/2023]
Abstract
TFF1 is a member of a unique family of gastrointestinal peptides. Loss of TFF1 expression has been observed in the majority of human gastric cancers and the biological significance of this loss has been demonstrated in a Tff1 knockout mouse model. However, few TFF1 gene mutations or allelic loss have also been documented. To understand the molecular mechanism repressing the TFF1 gene expression, the 5'-flanking region of the human TFF1 gene was characterized. We found a repressor region (-241 to -84), which is active in MKN45 and IMGE5 cells expressing endogenous TFF1 gene. A consensus binding site for C/EBPbeta was identified and EMSA analysis demonstrated specific binding of CEBPbeta. Mutation of this C/EBPbeta element potentiated the transactivation of TFF1 by 50% and 145% for MKN45 and IMGE5 cells respectively. Furthermore, co-transfection of C/EBPbeta isoforms specifically decreased TFF1 promoter activity. These findings suggest that C/EBPbeta is involved in the down-regulating of TFF1 gene expression and this mode of repression may account at least in part for the loss of TFF1 gene expression in transformed human and mice gastric epithelial cells.
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Affiliation(s)
- Narendra V Sankpal
- Division of Gastroenterology and Hepatology, University of Virginia Health System, Charlottesville, VA 22908-0708, USA
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Svotelis A, Doyon G, Bernatchez G, Désilets A, Rivard N, Asselin C. IL-1 beta-dependent regulation of C/EBP delta transcriptional activity. Biochem Biophys Res Commun 2005; 328:461-70. [PMID: 15694370 DOI: 10.1016/j.bbrc.2005.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Indexed: 11/19/2022]
Abstract
We have previously shown that the transcription factor C/EBP delta is involved in the intestinal inflammatory response. C/EBP delta regulates several inflammatory response genes, such as haptoglobin, in the rat intestinal epithelial cell line IEC-6 in response to IL-1. However, the different C/EBP delta domains involved in IL-1 beta-mediated transcriptional activation and the kinases implicated have not been properly defined. To address this, we determined the role of the p38 MAP kinase in the regulation of C/EBP delta transcriptional activity. The IL-1-dependent induction of the acute phase protein gene haptoglobin in IEC-6 cells was decreased in response to the p38 MAP kinase inhibitor SB203580, as determined by Northern blot. Transcriptional activity of C/EBP delta was repressed by the specific inhibitor of the p38 MAP kinase, as assessed by transient transfection assays. Mutagenesis studies and transient transfection assays revealed an important domain for transcriptional activation between amino acids 70 and 108. This domain overlapped with a docking site for the p38 MAP kinase, between amino acids 75 and 85, necessary to insure C/EBP delta phosphorylation. Deletion of this domain led to a decrease in basal transcriptional activity of C/EBP delta and in p300-dependent transactivation, as assessed by transient transfection assays, and in IL-1-dependent haptoglobin induction. This unusual arrangement of a kinase docking site within a transactivation domain may functionally be important for the regulation of C/EBP delta transcriptional activity.
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Affiliation(s)
- Amy Svotelis
- CIHR Group on Functional Development and Physiopathology of the Digestive Tract, Département d'Anatomie et Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Que., Canada J1H 5N4
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50
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Burkart AD, Mukherjee A, Sterneck E, Johnson PF, Mayo KE. Repression of the inhibin alpha-subunit gene by the transcription factor CCAAT/enhancer-binding protein-beta. Endocrinology 2005; 146:1909-21. [PMID: 15650079 DOI: 10.1210/en.2004-0842] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Inhibin is a dimeric peptide hormone produced in ovarian granulosa cells that suppresses FSH synthesis and secretion in the pituitary. Expression of inhibin alpha- and beta-subunit genes in the rodent ovary is positively regulated by FSH and negatively regulated after the preovulatory LH surge. We have investigated the role of the transcription factor CCAAT/enhancer-binding protein-beta (C/EBPbeta) in repressing the inhibin alpha-subunit gene. C/EBPbeta knockout mice fail to appropriately down-regulate inhibin alpha-subunit mRNA levels after treatment with human chorionic gonadotropin, indicating that C/EBPbeta may function to repress inhibin gene expression. The expression and regulation of C/EBPbeta were examined in rodent ovary, and these studies show that C/EBPbeta is expressed in ovary and granulosa cells and is induced in response to human chorionic gonadotropin. Transient cotransfections with an inhibin promoter-luciferase reporter in a mouse granulosa cell line, GRMO2 cells, show that C/EBPbeta is capable of repressing both basal and forskolin-stimulated inhibin gene promoter activities. An upstream binding site for C/EBPbeta in the inhibin alpha-subunit promoter was identified by electrophoretic mobility shift assays, which, when mutated, results in elevated inhibin promoter activity. However, C/EBPbeta also represses shorter promoter constructs lacking this site, and this component of repression is dependent on the more proximal promoter cAMP response element (CRE). Electrophoretic mobility shift assays show that C/EBPbeta effectively competes with CRE-binding protein for binding to this atypical CRE. Thus, there are two distinct mechanisms by which C/EBPbeta represses inhibin alpha-subunit gene expression in ovarian granulosa cells.
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Affiliation(s)
- Anna D Burkart
- Department of Biochemistry, Molecular Biology, and Cell Biology, and Center for Reproductive Science, Northwestern University, Evanston, Illinois 60208, USA
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