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Ren Y, Guo W, Qiao B. Abnormal expression of CEBPB promotes the progression of renal cell carcinoma through regulating the generation of IL-6. Heliyon 2023; 9:e20175. [PMID: 37767481 PMCID: PMC10520310 DOI: 10.1016/j.heliyon.2023.e20175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 09/03/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Background The CCAAT/enhancer-binding protein beta (CEBPB), a transcription factor regulating immune and inflammatory responses, has been implicated in the pathogenesis of various malignancies. However, its specific regulatory mechanism in renal cell carcinoma (RCC) remains poorly understood. Methods The expression of CEBPB was detected in RCC cells and tissues using qRT-PCR, western blotting and immunohistochemistry. ELISA assay was used to detect the immune factors regulated by CEBPB in supernatants. Additionally, western blotting was employed to measure the phosphorylation level of STAT3 and the expression levels of its downstream target genes. Results CEBPB was found to be overexpressed in both RCC tissues and cell lines, and its higher expression was associated with a lower survival rate. In RCC cells, CEBPB enhances the expression of IL6, consequently promoting the phosphorylation of STAT3 and the expression of its downstream target genes. This mechanism ultimately facilitates tumor progression. Conclusions The dysregulated expression of CEBPB facilitates RCC progression through the IL6/STAT3 pathway. CEBPB is a potential diagnostic markers and a novel effective therapeutic target for RCC patients.
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Affiliation(s)
- Yaoqiang Ren
- Departments of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Wenke Guo
- Department of Thyroid Surgery, Fenyang Hospital of Shanxi Province, Lüliang, Shanxi, China
| | - Baoping Qiao
- Departments of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
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2
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Amrute JM, Perry AM, Anand G, Cruchaga C, Hock KG, Farnsworth CW, Randolph GJ, Lavine KJ, Steed AL. Cell specific peripheral immune responses predict survival in critical COVID-19 patients. Nat Commun 2022; 13:882. [PMID: 35169146 PMCID: PMC8847593 DOI: 10.1038/s41467-022-28505-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 01/27/2022] [Indexed: 12/12/2022] Open
Abstract
SARS-CoV-2 triggers a complex systemic immune response in circulating blood mononuclear cells. The relationship between immune cell activation of the peripheral compartment and survival in critical COVID-19 remains to be established. Here we use single-cell RNA sequencing and Cellular Indexing of Transcriptomes and Epitomes by sequence mapping to elucidate cell type specific transcriptional signatures that associate with and predict survival in critical COVID-19. Patients who survive infection display activation of antibody processing, early activation response, and cell cycle regulation pathways most prominent within B-, T-, and NK-cell subsets. We further leverage cell specific differential gene expression and machine learning to predict mortality using single cell transcriptomes. We identify interferon signaling and antigen presentation pathways within cDC2 cells, CD14 monocytes, and CD16 monocytes as predictors of mortality with 90% accuracy. Finally, we validate our findings in an independent transcriptomics dataset and provide a framework to elucidate mechanisms that promote survival in critically ill COVID-19 patients. Identifying prognostic indicators among critical COVID-19 patients holds tremendous value in risk stratification and clinical management.
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Affiliation(s)
- Junedh M Amrute
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Alexandra M Perry
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gautam Anand
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Carlos Cruchaga
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Karl G Hock
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Christopher W Farnsworth
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Gwendalyn J Randolph
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Kory J Lavine
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Ashley L Steed
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA.
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Choi YB, Cousins E, Nicholas J. Novel Functions and Virus-Host Interactions Implicated in Pathogenesis and Replication of Human Herpesvirus 8. Recent Results Cancer Res 2021; 217:245-301. [PMID: 33200369 DOI: 10.1007/978-3-030-57362-1_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human herpesvirus 8 (HHV-8) is classified as a γ2-herpesvirus and is related to Epstein-Barr virus (EBV), a γ1-herpesvirus. One important aspect of the γ-herpesviruses is their association with neoplasia, either naturally or in animal model systems. HHV-8 is associated with B-cell-derived primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD), endothelial-derived Kaposi's sarcoma (KS), and KSHV inflammatory cytokine syndrome (KICS). EBV is also associated with a number of B-cell malignancies, such as Burkitt's lymphoma, Hodgkin's lymphoma, and posttransplant lymphoproliferative disease, in addition to epithelial nasopharyngeal and gastric carcinomas. Despite the similarities between these viruses and their associated malignancies, the particular protein functions and activities involved in key aspects of virus biology and neoplastic transformation appear to be quite distinct. Indeed, HHV-8 specifies a number of proteins for which counterparts had not previously been identified in EBV, other herpesviruses, or even viruses in general, and these proteins are believed to play vital functions in virus biology and to be involved centrally in viral pathogenesis. Additionally, a set of microRNAs encoded by HHV-8 appears to modulate the expression of multiple host proteins to provide conditions conductive to virus persistence within the host and possibly contributing to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus-host interactions and their potential roles in both virus biology and virus-associated disease.
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Affiliation(s)
- Young Bong Choi
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA.
| | - Emily Cousins
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA
| | - John Nicholas
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA
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4
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Novel insights and therapeutic approaches in idiopathic multicentric Castleman disease. Blood 2019; 132:2323-2330. [PMID: 30487129 DOI: 10.1182/blood-2018-05-848671] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/05/2018] [Indexed: 12/12/2022] Open
Abstract
Castleman disease (CD) describes a heterogeneous group of hematologic disorders that share characteristic lymph node histopathology. Patients of all ages present with either a solitary enlarged lymph node (unicentric CD) or multicentric lymphadenopathy (MCD) with systemic inflammation, cytopenias, and life-threatening multiple organ dysfunction resulting from a cytokine storm often driven by interleukin 6 (IL-6). Uncontrolled human herpesvirus-8 (HHV-8) infection causes approximately 50% of MCD cases, whereas the etiology is unknown in the remaining HHV-8-negative/idiopathic MCD cases (iMCD). The limited understanding of etiology, cell types, and signaling pathways involved in iMCD has slowed development of treatments and contributed to historically poor patient outcomes. Here, recent progress for diagnosing iMCD, characterizing etio-pathogenesis, and advancing treatments are reviewed. Several clinicopathological analyses provided the evidence base for the first-ever diagnostic criteria and revealed distinct clinical subtypes: thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS), which are both observed all over the world. In 2014, the anti-IL-6 therapy siltuximab became the first iMCD treatment approved by the US Food and Drug Administration, on the basis of a 34% durable response rate; consensus guidelines recommend it as front-line therapy. Recent cytokine and proteomic profiling has revealed normal IL-6 levels in many patients with iMCD and potential alternative driver cytokines. Candidate novel genomic alterations, dysregulated cell types, and signaling pathways have also been identified as candidate therapeutic targets. RNA sequencing for viral transcripts did not reveal novel viruses, HHV-8, or other viruses pathologically associated with iMCD. Despite progress, iMCD remains poorly understood. Further efforts to elucidate etiology, pathogenesis, and treatment approaches, particularly for siltuximab-refractory patients, are needed.
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5
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Fajgenbaum DC. Novel insights and therapeutic approaches in idiopathic multicentric Castleman disease. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2018; 2018:318-325. [PMID: 30504327 PMCID: PMC6245974 DOI: 10.1182/asheducation-2018.1.318] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Castleman disease (CD) describes a heterogeneous group of hematologic disorders that share characteristic lymph node histopathology. Patients of all ages present with either a solitary enlarged lymph node (unicentric CD) or multicentric lymphadenopathy (MCD) with systemic inflammation, cytopenias, and life-threatening multiple organ dysfunction resulting from a cytokine storm often driven by interleukin 6 (IL-6). Uncontrolled human herpesvirus-8 (HHV-8) infection causes approximately 50% of MCD cases, whereas the etiology is unknown in the remaining HHV-8-negative/idiopathic MCD cases (iMCD). The limited understanding of etiology, cell types, and signaling pathways involved in iMCD has slowed development of treatments and contributed to historically poor patient outcomes. Here, recent progress for diagnosing iMCD, characterizing etio-pathogenesis, and advancing treatments are reviewed. Several clinicopathological analyses provided the evidence base for the first-ever diagnostic criteria and revealed distinct clinical subtypes: thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, organomegaly (iMCD-TAFRO) or iMCD-not otherwise specified (iMCD-NOS), which are both observed all over the world. In 2014, the anti-IL-6 therapy siltuximab became the first iMCD treatment approved by the US Food and Drug Administration, on the basis of a 34% durable response rate; consensus guidelines recommend it as front-line therapy. Recent cytokine and proteomic profiling has revealed normal IL-6 levels in many patients with iMCD and potential alternative driver cytokines. Candidate novel genomic alterations, dysregulated cell types, and signaling pathways have also been identified as candidate therapeutic targets. RNA sequencing for viral transcripts did not reveal novel viruses, HHV-8, or other viruses pathologically associated with iMCD. Despite progress, iMCD remains poorly understood. Further efforts to elucidate etiology, pathogenesis, and treatment approaches, particularly for siltuximab-refractory patients, are needed.
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Affiliation(s)
- David C Fajgenbaum
- Division of Translational Medicine & Human Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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6
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7
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Chen EI, Crew KD, Trivedi M, Awad D, Maurer M, Kalinsky K, Koller A, Patel P, Kim Kim J, Hershman DL. Identifying Predictors of Taxane-Induced Peripheral Neuropathy Using Mass Spectrometry-Based Proteomics Technology. PLoS One 2015; 10:e0145816. [PMID: 26710119 PMCID: PMC4692419 DOI: 10.1371/journal.pone.0145816] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 12/09/2015] [Indexed: 11/19/2022] Open
Abstract
Major advances in early detection and therapy have significantly increased the survival of breast cancer patients. Unfortunately, most cancer therapies are known to carry a substantial risk of adverse long-term treatment-related effects. Little is known about patient susceptibility to severe side effects after chemotherapy. Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of taxanes. Recent advances in genome-wide genotyping and sequencing technologies have supported the discoveries of a number of pharmacogenetic markers that predict response to chemotherapy. However, effectively implementing these pharmacogenetic markers in the clinic remains a major challenge. On the other hand, recent advances in proteomic technologies incorporating mass spectrometry (MS) for biomarker discovery show great promise to provide clinically relevant protein biomarkers. In this study, we evaluated the association between protein content in serum exosomes and severity of CIPN. Women with early stage breast cancer receiving adjuvant taxane chemotherapy were assessed with the FACT-Ntx score and serum was collected before and after the taxane treatment. Based on the change in FACT-Ntx score from baseline to 12 month follow-up, we separated patients into two groups: those who had no change (Group 1, N = 9) and those who had a ≥20% worsening (Group 1, N = 8). MS-based proteomics technology was used to identify proteins present in serum exosomes to determine potential biomarkers. Mann-Whitney-Wilcoxon analysis was applied and maximum FDR was controlled at 20%. From the serum exosomes derived from this cohort, we identified over 700 proteins known to be in different subcellular locations and have different functions. Statistical analysis revealed a 12-protein signature that resulted in a distinct separation between baseline serum samples of both groups (q<0.2) suggesting that the baseline samples can predict subsequent neurotoxicity. These toxicity-associated biomarkers can be further validated in larger retrospective cohorts for their utility in identifying patients at high risk for CIPN.
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Affiliation(s)
- Emily I. Chen
- Department of Pharmacology, Columbia University Medical Center, New York, New York, United States of America
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Katherine D. Crew
- Department of Medicine, Columbia University Medical Center, New York, New York, United States of America
- Department of Epidemiology, Columbia University Medical Center, New York, New York, United States of America
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Meghna Trivedi
- Department of Medicine, Columbia University Medical Center, New York, New York, United States of America
| | - Danielle Awad
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Mathew Maurer
- Department of Medicine, Columbia University Medical Center, New York, New York, United States of America
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Kevin Kalinsky
- Department of Medicine, Columbia University Medical Center, New York, New York, United States of America
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Antonius Koller
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Purvi Patel
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Jenny Kim Kim
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
| | - Dawn L. Hershman
- Department of Medicine, Columbia University Medical Center, New York, New York, United States of America
- Department of Epidemiology, Columbia University Medical Center, New York, New York, United States of America
- Herbert Irving Comprehensive Cancer Center, Proteomics Shared Resource, Columbia University Medical Center, New York, New York, United States of America
- * E-mail:
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8
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Walch-Rückheim B, Mavrova R, Henning M, Vicinus B, Kim YJ, Bohle RM, Juhasz-Böss I, Solomayer EF, Smola S. Stromal Fibroblasts Induce CCL20 through IL6/C/EBPβ to Support the Recruitment of Th17 Cells during Cervical Cancer Progression. Cancer Res 2015; 75:5248-59. [PMID: 26631268 DOI: 10.1158/0008-5472.can-15-0732] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 08/26/2015] [Indexed: 12/22/2022]
Abstract
Cervical cancer is a consequence of persistent infection with human papillomaviruses (HPV). Progression to malignancy is linked to an inflammatory microenvironment comprising T-helper-17 (Th17) cells, a T-cell subset with protumorigenic properties. Neoplastic cells express only low endogenous levels of the Th17 chemoattractant CCL20, and therefore, it is unclear how Th17 cells are recruited to the cervical cancer tissue. In this study, we demonstrate that CCL20 was predominantly expressed in the stroma of cervical squamous cell carcinomas in situ. This correlated with stromal infiltration of CD4(+)/IL17(+) cells and with advancing International Federation of Gynecology and Obstetrics (FIGO) stage. Furthermore, we show that cervical cancer cells instructed primary cervical fibroblasts to produce high levels of CCL20 and to attract CD4/IL17/CCR6-positive cells, generated in vitro, in a CCL20/CCR6-dependent manner. Further mechanistic investigations identified cervical cancer cell-derived IL6 as an important mediator of paracrine CCL20 induction at the promoter, mRNA, and protein level in fibroblasts. CCL20 was upregulated through the recently described CCAAT/enhancer-binding protein β (C/EBPβ) pathway as shown with a dominant-negative version of C/EBPβ and through siRNA-mediated knockdown. In summary, our study defines a novel molecular mechanism by which cervical neoplastic cells shape their local microenvironment by instructing fibroblasts to support Th17 cell infiltration in a paracrine IL6/C/EBPβ-dependent manner. Th17 cells may in turn maintain chronic inflammation within high-grade cervical lesions to further promote cancer progression.
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Affiliation(s)
- Barbara Walch-Rückheim
- Institute of Virology and Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany.
| | - Russalina Mavrova
- Department of Obstetrics and Gynecology, Saarland University, Homburg/Saar, Germany
| | - Melanie Henning
- Institute of Virology and Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany
| | - Benjamin Vicinus
- Institute of Virology and Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany
| | - Yoo-Jin Kim
- Institute of Pathology, Saarland University, Homburg/Saar, Germany
| | | | - Ingolf Juhasz-Böss
- Department of Obstetrics and Gynecology, Saarland University, Homburg/Saar, Germany
| | | | - Sigrun Smola
- Institute of Virology and Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg/Saar, Germany
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9
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HHV-8-negative, idiopathic multicentric Castleman disease: novel insights into biology, pathogenesis, and therapy. Blood 2014; 123:2924-33. [PMID: 24622327 DOI: 10.1182/blood-2013-12-545087] [Citation(s) in RCA: 226] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Multicentric Castleman's disease (MCD) describes a heterogeneous group of disorders involving proliferation of morphologically benign lymphocytes due to excessive proinflammatory hypercytokinemia, most notably of interleukin-6. Patients demonstrate intense episodes of systemic inflammatory symptoms, polyclonal lymphocyte and plasma cell proliferation, autoimmune manifestations, and organ system impairment. Human herpes virus-8 (HHV-8) drives the hypercytokinemia in all HIV-positive patients and some HIV-negative patients. There is also a group of HIV-negative and HHV-8-negative patients with unknown etiology and pathophysiology, which we propose referring to as idiopathic MCD (iMCD). Here, we synthesize what is known about iMCD pathogenesis, present a new subclassification system, and propose a model of iMCD pathogenesis. MCD should be subdivided into HHV-8-associated MCD and HHV-8-negative MCD or iMCD. The lymphocyte proliferation, histopathology, and systemic features in iMCD are secondary to hypercytokinemia, which can occur with several other diseases. We propose that 1 or more of the following 3 candidate processes may drive iMCD hypercytokinemia: systemic inflammatory disease mechanisms via autoantibodies or inflammatory gene mutations, paraneoplastic syndrome mechanisms via ectopic cytokine secretion, and/or a non-HHV-8 virus. Urgent priorities include elucidating the process driving iMCD hypercytokinemia, identifying the hypercytokine-secreting cell, developing consensus criteria for diagnosis, and building a patient registry to track cases.
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10
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Zhang L, Pan J, Dong Y, Tweardy DJ, Dong Y, Garibotto G, Mitch WE. Stat3 activation links a C/EBPδ to myostatin pathway to stimulate loss of muscle mass. Cell Metab 2013; 18:368-79. [PMID: 24011072 PMCID: PMC3794464 DOI: 10.1016/j.cmet.2013.07.012] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Revised: 03/17/2013] [Accepted: 07/24/2013] [Indexed: 01/02/2023]
Abstract
Catabolic conditions like chronic kidney disease (CKD) cause loss of muscle mass by unclear mechanisms. In muscle biopsies from CKD patients, we found activated Stat3 (p-Stat3) and hypothesized that p-Stat3 initiates muscle wasting. We created mice with muscle-specific knockout (KO) that prevents activation of Stat3. In these mice, losses of body and muscle weights were suppressed in models with CKD or acute diabetes. A small-molecule that inhibits Stat3 activation produced similar responses, suggesting a potential for translation strategies. Using CCAAT/enhancer-binding protein δ (C/EBPδ) KO mice and C2C12 myotubes with knockdown of C/EBPδ or myostatin, we determined that p-Stat3 initiates muscle wasting via C/EBPδ, stimulating myostatin, a negative muscle growth regulator. C/EBPδ KO also improved survival of CKD mice. We verified that p-Stat3, C/EBPδ, and myostatin were increased in muscles of CKD patients. The pathway from p-Stat3 to C/EBPδ to myostatin and muscle wasting could identify therapeutic targets that prevent muscle wasting.
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Affiliation(s)
- Liping Zhang
- Nephrology Division, Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.
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11
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Rahman SM, Schroeder-Gloeckler JM, Janssen RC, Jiang H, Qadri I, Maclean KN, Friedman JE. CCAAT/enhancing binding protein beta deletion in mice attenuates inflammation, endoplasmic reticulum stress, and lipid accumulation in diet-induced nonalcoholic steatohepatitis. Hepatology 2007; 45:1108-17. [PMID: 17464987 DOI: 10.1002/hep.21614] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED Nonalcoholic steatohepatitis (NASH) is characterized by steatosis, inflammation, and oxidative stress. To investigate whether the transcription factor CCAAT/Enhancer binding protein (C/EBPbeta) is involved in the development of NASH, C57BL/6J wild-type (WT) or C/EBPbeta knockout (C/EBPbeta-/-) mice were fed either a methionine and choline deficient (MCD) diet or standard chow. These WT mice fed a MCD diet for 4 weeks showed a 2- to 3-fold increase in liver C/EBPbeta messenger RNA and protein, along with increased expression of lipogenic genes peroxisome proliferators-activated receptor gamma and Fas. WT mice also showed increased levels of the endoplasmic reticulum stress pathway proteins phosphorylated eukaryotic translation initiation factor alpha, phosphorylated pancreatic endoplasmic reticulum kinase, and C/EBP homologous protein, along with inflammatory markers phosphorylated nuclear factor kappaB and phosphorylated C-jun N-terminal kinase compared to chow-fed controls. Cytochrome P450 2E1 protein and acetyl coA oxidase messenger RNA involved in hepatic lipid peroxidation were also markedly increased in WT MCD diet-fed group. In contrast, C/EBPbeta-/- mice fed a MCD diet showed a 60% reduction in hepatic triglyceride accumulation and decreased liver injury as evidenced by reduced serum alanine aminotransferase and aspartate aminotransferase levels, and by H&E staining. Immunoblots and real-time qPCR data revealed a significant reduction in expression of stress related proteins and lipogenic genes in MCD diet-fed C/EBPbeta-/- mice. Furthermore, circulating TNFalpha and expression of acute phase response proteins CRP and SAP were significantly lower in C/EBPbeta-/- mice compared to WT mice. Conversely, C/EBPbeta over-expression in livers of WT mice increased steatosis, nuclear factor-kappaB, and endoplasmic reticulum stress, similar to MCD diet-fed mice. CONCLUSION Taken together, these data suggest a previously unappreciated molecular link between C/EBPbeta, hepatic steatosis and inflammation and suggest that increased C/EBPbeta expression may be an important factor underlying events leading to NASH.
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Affiliation(s)
- Shaikh Mizanoor Rahman
- Department of Pediatrics, University of Colorado at Denver and Health Sciences Center, Aurora, CO 80045, USA
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12
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Hodge DR, Xiao W, Peng B, Cherry JC, Munroe DJ, Farrar WL. Enforced expression of superoxide dismutase 2/manganese superoxide dismutase disrupts autocrine interleukin-6 stimulation in human multiple myeloma cells and enhances dexamethasone-induced apoptosis. Cancer Res 2005; 65:6255-63. [PMID: 16024627 DOI: 10.1158/0008-5472.can-04-4482] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Autocrine pathways of proliferative and anti-apoptotic growth factors represent a serious impediment to the treatment of many types of tumors. In particular, interleukin-6 (IL-6), a pleiotropic cytokine known to play a critical role in the survival and growth of multiple myeloma cells, participates in an autocrine stimulation loop that serves to inhibit the induction of apoptosis during chemotherapy. Manganese superoxide dismutase (MnSOD) is an important antioxidant enzyme encoded by the SOD2 gene that attenuates oxidative free radicals in the mitochondria by catalyzing the formation of hydrogen peroxide from superoxide radicals. Transcription factor activity and binding is influenced by the oxidative state of cells, and dysregulation of MnSOD levels can result in abnormal patterns of gene expression. In the human multiple myeloma cell line IM-9, an autocrine IL-6 loop exists, which enables the cell to resist the effects of dexamethasone, a common treatment for multiple myeloma. Here, we show that SOD2 expression is epigenetically silenced in IM-9 cells, and replacement of MnSOD reduces cell proliferation and partially restores susceptibility to dexamethasone. The restoration of MnSOD also serves to decrease the expression levels of IL-6 by reducing the ability of activator protein-1, an important mediator of IL-6 expression in multiple myeloma cells, to bind to its enhancer site. These results show the importance of free radical-mediated dysregulation of autocrine growth factor loops in tumor cells and their effect on cell growth and response to chemotherapy.
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Affiliation(s)
- David R Hodge
- Laboratory of Molecular Immunoregulation, Cytokine Molecular Mechanisms Section, Center for Cancer Research, National Cancer Institute at Frederick, Maryland, USA.
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13
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Selvaraj V, Bunick D, Finnigan-Bunick C, Johnson RW, Wang H, Liu L, Cooke PS. Gene Expression Profiling of 17β-Estradiol and Genistein Effects on Mouse Thymus. Toxicol Sci 2005; 87:97-112. [PMID: 15947025 DOI: 10.1093/toxsci/kfi219] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Estrogen regulates thymic development and involution and modulates immune function. Despite its critical role in thymus, as well as in autoimmune disorders, the mechanism by which estrogen affects the thymus is not well understood. We previously reported that the estrogenic soy isoflavone genistein, as well as 17beta-estradiol (E2), could induce thymic involution, but genistein effects were only partially mediated through estrogen receptors. To provide insights into mechanisms of estrogenic effects in the thymus, we investigated thymic gene expression changes induced by E2 (125 ng/day) and genistein (1500 ppm in feed) in weanling mice using high-density DNA arrays. We identified several E2-responsive genes involved in thymic development and thymocyte signaling during selection and maturation. Functional characterization indicated effects on genes involved in transcription, apoptosis, and the cell cycle. This study also identified changes in several E2-regulated transcripts essential to maintain immune self-tolerance. E2 upregulated more genes than genistein, while genistein downregulated more genes than E2. Though each treatment regulated several genes not altered by the other, there was considerable overlap in the genes regulated by E2 and genistein. Changes in transcription factors and cell cycle factors were consistent with decreases in cell proliferation induced by both genistein and E2. As indicated by the regulation of non-E2-responsive genes, genistein also induced unique effects through non-estrogenic mechanisms. The specific downregulation of the CD4 coreceptor transcript by genistein was consistent with the decline of CD4+ thymocytes in genistein-treated mice in our previous study. This is the first study identifying E2 and genistein target genes in the thymus. These findings provide new mechanistic insights toward explaining estrogen action on thymocyte development, selection, and maturation, as well as the effects of genistein on prenatal and neonatal thymic development and function.
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Affiliation(s)
- Vimal Selvaraj
- Department of Veterinary Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, USA
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Schrem H, Klempnauer J, Borlak J. Liver-enriched transcription factors in liver function and development. Part II: the C/EBPs and D site-binding protein in cell cycle control, carcinogenesis, circadian gene regulation, liver regeneration, apoptosis, and liver-specific gene regulation. Pharmacol Rev 2004; 56:291-330. [PMID: 15169930 DOI: 10.1124/pr.56.2.5] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In the first part of our review (see Pharmacol Rev 2002;54:129-158), we discussed the basic principles of gene transcription and the complex interactions within the network of hepatocyte nuclear factors, coactivators, ligands, and corepressors in targeted liver-specific gene expression. Now we summarize the role of basic region/leucine zipper protein family members and particularly the albumin D site-binding protein (DBP) and the CAAT/enhancer-binding proteins (C/EBPs) for their importance in liver-specific gene expression and their role in liver function and development. Specifically, regulatory networks and molecular interactions were examined in detail, and the experimental findings summarized in this review point to pivotal roles of DBP and C/EBPs in cell cycle control, carcinogenesis, circadian gene regulation, liver regeneration, apoptosis, and liver-specific gene regulation. These regulatory proteins are therefore of great importance in liver physiology, liver disease, and liver development. Furthermore, interpretation of the vast data generated by novel genomic platform technologies requires a thorough understanding of regulatory networks and particularly the hierarchies that govern transcription and translation of proteins as well as intracellular protein modifications. Thus, this review aims to stimulate discussions on directions of future research and particularly the identification of molecular targets for pharmacological intervention of liver disease.
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Affiliation(s)
- Harald Schrem
- Center for Drug Research and Medical Biotechnology, Fraunhofer Institut für Toxikologie und Experimentelle Medizin, Nicolai Fuchs Str. 1, 30625 Hannover, Germany
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15
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Gold JA, Hoshino Y, Tanaka N, Rom WN, Raju B, Condos R, Weiden MD. Surfactant protein A modulates the inflammatory response in macrophages during tuberculosis. Infect Immun 2004; 72:645-50. [PMID: 14742504 PMCID: PMC321592 DOI: 10.1128/iai.72.2.645-650.2004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Tuberculosis leads to immune activation and increased human immunodeficiency virus type 1 (HIV-1) replication in the lung. However, in vitro models of mycobacterial infection of human macrophages do not fully reproduce these in vivo observations, suggesting that there are additional host factors. Surfactant protein A (SP-A) is an important mediator of innate immunity in the lung. SP-A levels were assayed in the human lung by using bronchoalveolar lavage (BAL). There was a threefold reduction in SP-A levels during tuberculosis only in the radiographically involved lung segments, and the levels returned to normal after 1 month of treatment. The SP-A levels were inversely correlated with the percentage of neutrophils in BAL fluid, suggesting that low SP-A levels were associated with increased inflammation in the lung. Differentiated THP-1 macrophages were used to test the effect of decreasing SP-A levels on immune function. In the absence of infection with Mycobacterium tuberculosis, SP-A at doses ranging from 5 to 0.01 micro g/ml inhibited both interleukin-6 (IL-6) production and HIV-1 long terminal repeat (LTR) activity. In macrophages infected with M. tuberculosis, SP-A augmented both IL-6 production and HIV-1 LTR activity. To better understand the effect of SP-A, we measured expression of CAAT/enhancer binding protein beta (C/EBPbeta), a transcription factor central to the regulation of IL-6 and the HIV-1 LTR. In macrophages infected with M. tuberculosis, SP-A reduced expression of a dominant negative isoform of C/EBPbeta. These data suggest that SP-A has pleiotropic effects even at the low concentrations found in tuberculosis patients. This protein augments inflammation in the presence of infection and inhibits inflammation in uninfected macrophages, protecting uninvolved lung segments from the deleterious effects of inflammation.
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Affiliation(s)
- Jeffrey A Gold
- Division of Pulmonary and Critical Care Medicine, New York University School of Medicine and Bellevue Hospital Chest Service, New York, New York 10016, USA
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16
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Abbud RA, Kelleher R, Melmed S. Cell-specific pituitary gene expression profiles after treatment with leukemia inhibitory factor reveal novel modulators for proopiomelanocortin expression. Endocrinology 2004; 145:867-80. [PMID: 14576184 DOI: 10.1210/en.2003-0897] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Leukemia inhibitory factor (LIF) mediates the hypothalamo-pituitary-adrenal stress response. Transgenic mice overexpressing LIF in the developing pituitary have altered pituitary differentiation with expansion of corticotropes, maintenance of Rathke's cleft cysts, and suppression of all other pituitary cell types. Affymetrix GeneChips were used to identify modulators of LIF effects in corticotrope (AtT-20) and somatolactotrope (GH(3)) cells. In addition to genes known to respond to LIF in corticotrope cells [e.g. suppressor of cytokine signaling-3 (SOCS-3), signal transducer and activator of transcription-3, SH2 domain-containing tyrosine phosphatase-1, and proopiomelanocortin (POMC)], corticotrope-specific changes were also observed for genes involved in glycolysis and gluconeogenesis, transcription factors, signaling molecules, and expressed sequence tags. Two transcription factors identified, CCAAT/enhancer-binding protein beta (C/EBPbeta) and glial cell-derived neurotrophic factor (GDNF)-inducible factor (GIF), dose-dependently induced expression of the rat POMC promoter when overexpressed in AtT-20 cells. LIF further induced POMC transcription with C/EBPbeta, but not with GIF. C/EBPbeta also induced expression of the SOCS-3 promoter that was further enhanced by cotreatment with LIF. However, GIF did not affect SOCS-3 expression. These results indicate that C/EBPbeta and GIF are downstream effectors of LIF corticotrope action. LIF also stimulates the expression of inhibitors of its actions, such as SOCS-3 and SH2 domain-containing tyrosine phosphatase-1. alpha(2)-HS-glycoprotein (AHSG)/fetuin, a secreted protein that antagonizes bone TGFbeta/bone morphogenic protein signaling, was induced by LIF in a signal transducer and activator of transcription-3-dependent fashion. Pretreatment with AHSG/fetuin blocked LIF-induced expression of the POMC promoter independently of SOCS-3. Thus, using GeneChips, C/EBPbeta and GIF have been identified as novel mediators and AHSG/fetuin as an inhibitor of LIF action in corticotropes.
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Affiliation(s)
- Rula A Abbud
- Division of Endocrinology, Department of Medicine, Cedars Sinai Medical Center, Los Angeles, CA 90048, USA
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17
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Kamaraju AK, Adjalley S, Zhang P, Chebath J, Revel M. C/EBP-delta induction by gp130 signaling. Role in transition to myelin gene expressing phenotype in a melanoma cell line model. J Biol Chem 2003; 279:3852-61. [PMID: 14600146 DOI: 10.1074/jbc.m310443200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Expression of genes encoding structural myelin proteins marks the inception of the myelinating Schwann cell (SC) phenotype. Earlier embryonic SC as well as adult non-myelinating SC produce the intermediate filament glial fibrillary acid protein (GFAP), which disappears from the myelinating SC. We previously observed that triggering of the gp130 receptor system by the IL6RIL6 ligand, comprising interleukin-6 (IL-6) fused to the soluble IL-6 receptor, induces myelin gene expression in rat embryonic dorsal root ganglia (DRG) cultures as well as in the murine melanoma cell line B16/F10.9. Study of target genes regulated by IL6RIL6 indicates a strong and selective induction of the transcriptional regulator C/EBP-delta in DRG cultures and in the F10.9 cell line. As shown here, silencing of C/EBP-delta mRNA and protein expression by introduction of small interference RNA-producing plasmids in the F10.9 cells prevented the induction of myelin protein zero (P0) and myelin basic protein (MBP) mRNAs by IL6RIL6. Doxycycline-regulated overexpression of C/EBP-delta was sufficient to induce accumulation of P0 and MBP mRNAs, the effect being selective, because C/EBP-delta did not affect several other genes strongly regulated by IL6RIL6. Interestingly, GFAP was inhibited by C/EBP-delta overexpression, leading to a modulation of the ratio between myelin gene products versus GFAP and suggesting that C/EBP-delta plays a role in the switch to a myelinating phenotype. The down-regulation of Pax3, also typical of the transition to myelinating cells, was observed after C/EBP-delta expression in correlation to P0 induction and to decrease of melanogenesis and cell growth. In cultures of dissociated cells of embryonic rat DRG, where we knocked-down the C/EBP-delta mRNA, we found an inhibition of P0 mRNA induction by IL6RIL6, showing that the role of C/EBP-delta on this myelin gene is not unique to the melanoma system.
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Affiliation(s)
- Anil K Kamaraju
- Department of Molecular Genetics, Weizmann Institute of Science, Rehov Herzl, Rehovot 76100, Israel
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18
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Duan HO, Simpson-Haidaris PJ. Functional analysis of interleukin 6 response elements (IL-6REs) on the human gamma-fibrinogen promoter: binding of hepatic Stat3 correlates negatively with transactivation potential of type II IL-6REs. J Biol Chem 2003; 278:41270-81. [PMID: 12900415 DOI: 10.1074/jbc.m304210200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Several families of transcription factors play important roles in modulating liver-specific gene expression during an acute phase response (APR). Stat3/APR factor is the main transactivator of gene expression by the interleukin (IL)-6 family of cytokines signaling through gp130. During an APR, fibrinogen (FBG) genes are coordinately up-regulated by IL-6 and glucocorticoids. Except for rat gammaFBG, attempts to demonstrate direct binding of IL-6-activated Stat3 to FBG CTGGGAA promoter elements have not been successful. Herein we show the presence of three functional type II IL-6 response elements (IL-6REs) on the human gammaFBG promoter and that the magnitude of Stat3 binding to these elements correlates negatively with their functional activity in reporter gene assays. Stat3-specific binding to gammaFBG IL-6REs was confirmed by cross-competition with alpha2-macroglobulin IL-6RE and specific interactions with anti-Stat3 in electrophoretic mobility shift assays. All type II IL-6REs contributed to full promoter activity; however, transactivation from Site II at -306 to -301 was strongest. In contrast to a previous report, IL-6 failed to induce activation of serum amyloid A-activating factor-1/c-Myc-associated zinc finger protein (SAF-1/MAZ), and mutation of the SAF-1RE had little effect on IL-6 induction of gammaFBG promoter activity. In the absence of a functional glucocorticoid receptor response element, dexamethasone potentiated IL-6-induced gammaFBG promoter activity 2-fold, requiring promoter-proximal Site I and Site II; the promoter-distal Site III had no effect on dexamethasone potentiation of IL-6-induced promoter activity. Notably the propensity for Stat3 binding to human gammaFBG IL-6REs was low compared with Stat3 binding to the alpha2-macroglobulin IL-6RE. Together these data suggest that Stat3 transactivation via IL-6REs on FBG promoters likely involves participation of additional transcription factors and/or coactivators to achieve optimal coordinated up-regulation during an APR.
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Affiliation(s)
- Hai Ou Duan
- Department of Medicine, University of Rochester School of Medicine and Dentistry Rochester, New York 14642, USA
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19
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Ghoshal K, Majumder S, Zhu Q, Hunzeker J, Datta J, Shah M, Sheridan JF, Jacob ST. Influenza virus infection induces metallothionein gene expression in the mouse liver and lung by overlapping but distinct molecular mechanisms. Mol Cell Biol 2001; 21:8301-17. [PMID: 11713267 PMCID: PMC99995 DOI: 10.1128/mcb.21.24.8301-8317.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Accepted: 09/19/2001] [Indexed: 11/20/2022] Open
Abstract
Metallothionein I (MT-I) and MT-II have been implicated in the protection of cells against reactive oxygen species (ROS), heavy metals, and a variety of pathological and environmental stressors. Here, we show a robust increase in MT-I/MT-II mRNA level and MT proteins in the livers and lungs of C57BL/6 mice exposed to the influenza A/PR8 virus that infects the upper respiratory tract and lungs. Interleukin-6 (IL-6) had a pronounced effect on the induction of these genes in the liver but not the lung. Treatment of the animals with RU-486, a glucocorticoid receptor antagonist, inhibited induction of MT-I/MT-II in both liver and lung, revealing a direct role of glucocorticoid that is increased upon infection in this induction process. In vivo genomic footprinting (IVGF) analysis demonstrated involvement of almost all metal response elements, major late transcription factor/antioxidant response element (MLTF/ARE), the STAT3 binding site on the MT-I upstream promoter, and the glucocorticoid responsive element (GRE1), located upstream of the MT-II gene, in the induction process in the liver and lung. In the lung, inducible footprinting was also identified at a unique gamma interferon (IFN-gamma) response element (gamma-IRE) and at Sp1 sites. The mobility shift analysis showed activation of STAT3 and the glucocorticoid receptor in the liver and lung nuclear extracts, which was consistent with the IVGF data. Analysis of the newly synthesized mRNA for cytokines in the infected lung by real-time PCR showed a robust increase in the levels of IL-10 and IFN-gamma mRNA that can activate STAT3 and STAT1, respectively. A STAT1-containing complex that binds to the gamma-IRE in vitro was activated in the infected lung. No major change in MLTF/ARE DNA binding activity in the liver and lung occurred after infection. These results have demonstrated that MT-I and MT-II can be induced robustly in the liver and lung following experimental influenza virus infection by overlapping but distinct molecular mechanisms.
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Affiliation(s)
- K Ghoshal
- Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University, 333 Hamilton Hall, 1645 Neil Ave., Columbus, OH 43210, USA
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Barreda DR, Belosevic M. Transcriptional regulation of hemopoiesis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2001; 25:763-789. [PMID: 11602195 DOI: 10.1016/s0145-305x(01)00035-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The regulation of blood cell formation, or hemopoiesis, is central to the replenishment of mature effector cells of innate and acquired immune responses. These cells fulfil specific roles in the host defense against invading pathogens, and in the maintenance of homeostasis. The development of hemopoietic cells is under stringent control from extracellular and intracellular stimuli that result in the activation of specific downstream signaling cascades. Ultimately, all signal transduction pathways converge at the level of gene expression where positive and negative modulators of transcription interact to delineate the pattern of gene expression and the overall cellular hemopoietic response. Transcription factors, therefore, represent a nodal point of hemopoietic control through the integration of the various signaling pathways and subsequent modulation of the transcriptional machinery. Transcription factors can act both positively and negatively to regulate the expression of a wide range of hemopoiesis-relevant genes including growth factors and their receptors, other transcription factors, as well as various molecules important for the function of developing cells. The expression of these genes is dependent on the complex interactions between transcription factors, co-regulatory molecules, and specific binding sequences on the DNA. Recent advances in various vertebrate and invertebrate systems emphasize the importance of transcription factors for hemopoiesis control and the evolutionary conservation of several of such mechanisms. In this review we outline some of the key issues frequently identified in studies of the transcriptional regulation of hemopoietic gene expression. In teleosts, we expect that the characterization of several of these transcription factors and their regulatory mechanisms will complement recent advances in a number of fish systems where identification of cytokine and other hemopoiesis-relevant factors are currently under investigation.
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Affiliation(s)
- D R Barreda
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
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21
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Abstract
This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The presentation was Nonalcoholic fatty liver disease: Implications for alcoholic liver disease pathogenesis, by Anna Mae Diehl.
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Affiliation(s)
- A M Diehl
- Department of Medicine, The Johns Hopkins University, Baltimore, Maryland 21205, USA.
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22
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Georganas C, Liu H, Perlman H, Hoffmann A, Thimmapaya B, Pope RM. Regulation of IL-6 and IL-8 expression in rheumatoid arthritis synovial fibroblasts: the dominant role for NF-kappa B but not C/EBP beta or c-Jun. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:7199-206. [PMID: 11120852 DOI: 10.4049/jimmunol.165.12.7199] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) produce IL-6 and IL-8, which contribute to inflammation and joint damage. The promoters of both cytokines possess binding sites for NF-kappaB, C/EBPbeta, and c-Jun, but the contribution of each to the regulation of IL-6 and IL-8 in RA FLS is unknown. We employed adenoviral-mediated gene delivery of a nondegradable IkappaBalpha, or dominant-negative versions of C/EBPbeta or c-Jun, to determine the contribution of each transcription factor to IL-6 and IL-8 expression. Inhibition of NF-kappaB activation significantly reduced the spontaneous and IL-1beta-induced secretion of IL-6 and IL-8 by RA FLS and the IL-1ss-induced production of IL-6 and IL-8 by human dermal fibroblasts. Inhibition of C/EBPbeta modestly reduced constitutive and IL-1beta-induced IL-6 by RA FLS, but not by human dermal fibroblasts, and had no effect on IL-8. Inhibition of c-Jun/AP-1 had no effect on the production of either IL-6 or IL-8. Employing gel shift assays, NF-kappaB, C/EBPbeta, and c-Jun were constitutively activated in RA FLS, but only NF-kappaB and c-Jun activity increased after IL-1beta. The reduction of cytokines by IkappaBalpha was mediated through inhibition of NF-kappaB activation, which resulted in decreased IL-6 and IL-8 mRNA. NF-kappaB was essential for IL-6 expression, because fibroblasts in which both NF-kappaB p50/p65 genes were deleted failed to express IL-6 in response to IL-1. These findings document the importance of NF-kappaB for the regulation of the constitutive and IL-1beta-stimulated expression of IL-6 and IL-8 by RA FLS and support the role of inhibition of NF-kappaB as a therapeutic goal in RA.
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Affiliation(s)
- C Georganas
- Division of Rheumatology, Department of Medicine and the Department of Microbiology and Immunology, Northwestern University VA Chicago, Lakeside Medical School, Chicago, IL 60611, USA
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Pope R, Mungre S, Liu H, Thimmapaya B. Regulation of TNF-alpha expression in normal macrophages: the role of C/EBPbeta. Cytokine 2000; 12:1171-81. [PMID: 10930293 DOI: 10.1006/cyto.2000.0691] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
C/EBPbeta is present in monocytes and macrophages, binds to the proximal region of the TNF-alpha promoter, and contributes to its regulation. This study was performed to characterize the ability of C/EBPbeta to regulate the TNF-alpha gene in myelomonocytic cells and primary macrophages. In transient transfection assays, overexpression of wild type C/EBPbeta resulted in a 3-4-fold activation of a 120 base pair TNF-alpha promoter-reporter construct, while overexpression of a dominant negative (DN) C/EBPbeta inhibited LPS-induced activation. In vitro monocyte-differentiated macrophages, infected with an adenoviral vector expressing the DN C/EBPbeta (AdDNC/EBPbeta) or the control Adbetagal, expressed their transgenes weakly, however expression was greatly enhanced in the presence of PMA. Infection with AdDNC/EBPbeta resulted in 60% suppression of LPS induced TNFalpha secretion compared to Adbetagal infection (P<0.001) in PMA-treated macrophages. Northern blot analysis demonstrated approximately a 40% reduction of the TNF-alpha mRNA in the presence of the DN C/EBPbeta, suggesting that the effect of the DN C/EBPbeta was at the transcriptional level. In contrast, AdDNC/EBPbeta infection did not result in inhibition of LPS-induced TNF-alpha secretion in the absence of PMA. Further, DN versions of both C/EBPbeta and c-Jun, but not NF-kappaB p65, suppressed PMA-induced TNF-alpha secretion in macrophages. These observations demonstrate that, C/EBPbeta and c-Jun contribute to the regulation of the TNF-alpha gene in normal macrophages following treatment with PMA.
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Affiliation(s)
- R Pope
- Department of Medicine, Division of Arthritis and Connective Tissue Diseases and the Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, IL 60611, USA
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Dlaska M, Weiss G. Central Role of Transcription Factor NF-IL6 for Cytokine and Iron-Mediated Regulation of Murine Inducible Nitric Oxide Synthase Expression. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.10.6171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We have previously shown that iron regulates the transcription of inducible nitric oxide synthase (iNOS). To elucidate the underlying mechanisms we performed a series of transient transfections of murine fibroblast (NIH-3T3) and macrophage-like cells (J774.A1) with reporter plasmids containing the iNOS promoter and deletions thereof. By means of this and subsequent DNase I footprinting analysis we identified a regulatory region between −153 and −142 bp upstream of the transcriptional start site of the iNOS promoter that was sensitive to regulation by iron perturbation. Gel shift and supershift assays revealed that the responsible protein for this observation is NF-IL6, a member of the CCAAT/enhancer binding protein family of transcription factors. Binding of NF-IL6 to its consensus motif within the iNOS promoter was inducible by IFN-γ and/or LPS, was reduced by iron, and was enhanced by the iron chelator desferrioxamine. Introduction of a double mutation into the NF-IL6 binding site (−153/−142) of an iNOS promoter construct resulted in a reduction of IFN-γ/LPS inducibility by >90% and also impaired iron mediated regulation of the iNOS promoter. Our results provide evidence that this NF-IL6 binding site is of central importance for maintaining a high transcriptional rate of the iNOS gene after IFN-γ/LPS stimulation, and that NF-IL6 may cooperate with hypoxia inducible factor-1 in the orchestration of iron-mediated regulation of iNOS.
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Affiliation(s)
- Margit Dlaska
- Department of Internal Medicine, University of Innsbruck, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine, University of Innsbruck, Innsbruck, Austria
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Diehl AM. Roles of CCAAT/enhancer-binding proteins in regulation of liver regenerative growth. J Biol Chem 1998; 273:30843-6. [PMID: 9812973 DOI: 10.1074/jbc.273.47.30843] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The expressions and activities of several CCAAT/enhancer-binding proteins (C/EBP) isoforms fluctuate in the regenerating liver. The physiological implications of these variations in C/EBP function remain poorly characterized in the setting of regeneration. However, lessons learned in various hepatocyte cell lines and by studying primary hepatocytes from transgenic C/EBPalpha-deficient mice suggest that the C/EBP isoforms are likely to influence proliferation, differentiated gene expression, and survival in mature, adult hepatocytes. In addition, these factors are potentially important modulators of liver nonparenchymal cell genes, including those that encode matrix molecules and growth factors that are required for successful liver regeneration. The possibility that members of the C/EBP family of transcription factors actively participate in many aspects of the regenerative response to liver injury is strengthened by growing evidence that many hepatocyte mitogens and co-mitogens regulate C/EBP activity. Furthermore, the C/EBPs themselves appear to regulate the expression of some of these growth regulators.
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Affiliation(s)
- A M Diehl
- The Johns Hopkins University, Baltimore, Maryland 21205, USA.
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