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Wang J, Liu S, Shi J, Liu H, Li J, Zhao S, Yi Z. The Role of lncRNAs in Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells. Curr Stem Cell Res Ther 2020; 15:243-249. [PMID: 31880266 DOI: 10.2174/1574888x15666191227113742] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 02/01/2023]
Abstract
Bone Marrow Mesenchymal Stem Cells (BMSCs) are one of the primary cells found in the bone marrow, and they can differentiate into osteoblasts, chondrocytes, adipocytes and even myoblasts, and are, therefore, considered pluripotent cells. Because of their multipotential differentiation, selfrenewal capability, immunomodulation and other potential activities, BMSCs have become an important source of seed cells for gene therapy, tissue engineering, cell replacement therapy and regenerative medicine. Long non-coding RNA (lncRNA) is an RNA molecule greater than 200 nucleotides in length that is expressed in a variety of species, including animals, plants, yeast, prokaryotes, and viruses, but lacks an apparent open reading frame, and does not have the function of translation into proteins. Many studies have shown that lncRNAs play an important role in the osteogenic differentiation of BMSCs. Here, we describe the role of lncRNAs in the osteogenic differentiation of BMSCs, in order to provide a new theoretical and experimental basis for bone tissue engineering and clinical treatment.
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Affiliation(s)
- Jicheng Wang
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China.,Xi'an Medical University, Xi'an 710068, China
| | - Shizhang Liu
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Jiyuan Shi
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Huitong Liu
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Jingyuan Li
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China
| | - Song Zhao
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China.,Xi'an Medical University, Xi'an 710068, China
| | - Zhi Yi
- Department of Orthopaedic, Shaanxi Provincial People's Hospital, Xi'an 710068, China
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Peng F, Tian Y, Ma J, Xu Z, Wang S, Tang M, Lei J, Gong G, Jiang Y. CAT1 silencing inhibits TGF-β1-induced mouse hepatic stellate cell activation in vitro and hepatic fibrosis in vivo. Cytokine 2020; 136:155288. [PMID: 32980687 DOI: 10.1016/j.cyto.2020.155288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/31/2022]
Abstract
Hepatic fibrosis is characterized by abnormal accumulation of extracellular matrix (ECM). Hepatic stellate cells (HSCs) are the primary cells that produce ECM in response to hepatic injury, and transforming growth factor-beta (TGF-β) has been regarded as the central stimulus responsible for HSC-mediated ECM production. In the present study, we attempted to identify a critical factor in HSC activation and the underlying mechanism. By analyzing online microarray expression profiles, we found that the expression of high-affinity cationic amino acid transporter 1 (CAT1) was upregulated in hepatic fibrosis models and activated HSCs. We isolated and identified mouse HSCs (MHSCs) and found that in these cells, CAT1 was most highly upregulated by TGF-β1 stimulation in both time- and dose-dependent manners. In vitro, CAT1 overexpression further enhanced, while CAT1 silencing inhibited, the effect of TGF-β1 in promoting MHSC activation. In vivo, CAT1 silencing significantly improved the hepatic fibrosis induced by both CCl4 and non-alcoholic fatty liver disease (NAFLD). In summary, CAT1 was significantly upregulated in TGF-β1-activated MHSCs and mice with hepatic fibrosis. CAT1 silencing inhibited TGF-β1-induced MHSC activation in vitro and fibrogenic changes in vivo. CAT1 is a promising target for hepatic fibrosis treatment that requites further investigation in human cells and clinical practice.
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Affiliation(s)
- Feng Peng
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yi Tian
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Jing Ma
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Zhenyu Xu
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Sujuan Wang
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Min Tang
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Jianhua Lei
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Guozhong Gong
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yongfang Jiang
- Liver Diseases Research Center, The Second Xiangya Hospital, Central South University, Changsha 410011, China.
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3
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Gong Y, Yang Y. Activation of Nrf2/AREs-mediated antioxidant signalling, and suppression of profibrotic TGF-β1/Smad3 pathway: a promising therapeutic strategy for hepatic fibrosis - A review. Life Sci 2020; 256:117909. [PMID: 32512009 DOI: 10.1016/j.lfs.2020.117909] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/19/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
Abstract
Hepatic fibrosis (HF) is a wound-healing response that occurs during chronic liver injury and features by an excessive accumulation of extracellular matrix (ECM) components. Activation of hepatic stellate cell (HSC), the leading effector in HF, is responsible for overproduction of ECM. It has been documented that transforming growth factor-β1 (TGF-β1) stimulates superfluous accumulation of ECM and triggers HSCs activation mainly via canonical Smad-dependent pathway. Also, the pro-fibrogenic TGF-β1 is correlated with generation of reactive oxygen species (ROS) and inhibition of antioxidant mechanisms. Moreover, involvement of oxidative stress (OS) can be clearly elucidated as a fundamental event in liver fibrogenesis. Nuclear factor erythroid 2-related factor 2-antioxidant response elements (Nrf2-AREs) pathway, a group of OS-mediated transcription factors with diverse downstream targets, is associated with the induction of diverse detoxifying enzymes and the most pivotal endogenous antioxidative system. More specifically, Nrf2-AREs pathway has recently assigned as a new therapeutic target for cure of HF. The overall goal of this review will focus on recent findings about activation of Nrf2-AREs-mediated antioxidant and suppression of profibrotic TGF-β1/Smad3 pathway in the liver, providing an overview of recent advances in transcriptional repressors that dislocated during HF formation, and highlighting possible novel therapeutic targets for liver fibrosis.
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Affiliation(s)
- Yongfang Gong
- Department of Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education, Hefei 230032, China
| | - Yan Yang
- Department of Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education, Hefei 230032, China.
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Feng T, Dzieran J, Gu X, Marhenke S, Vogel A, Machida K, Weiss TS, Ruemmele P, Kollmar O, Hoffmann P, Grässer F, Allgayer H, Fabian J, Weng HL, Teufel A, Maass T, Meyer C, Lehmann U, Zhu C, Mertens PR, Gao CF, Dooley S, Meindl-Beinker NM. Smad7 regulates compensatory hepatocyte proliferation in damaged mouse liver and positively relates to better clinical outcome in human hepatocellular carcinoma. Clin Sci (Lond) 2015; 128:761-74. [PMID: 25602745 PMCID: PMC10618913 DOI: 10.1042/cs20140606] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Transforming growth factor β (TGF-β) is cytostatic towards damage-induced compensatory hepatocyte proliferation. This function is frequently lost during hepatocarcinogenesis, thereby switching the TGF-β role from tumour suppressor to tumour promoter. In the present study, we investigate Smad7 overexpression as a pathophysiological mechanism for cytostatic TGF-β inhibition in liver damage and hepatocellular carcinoma (HCC). Transgenic hepatocyte-specific Smad7 overexpression in damaged liver of fumarylacetoacetate hydrolase (FAH)-deficient mice increased compensatory proliferation of hepatocytes. Similarly, modulation of Smad7 expression changed the sensitivity of Huh7, FLC-4, HLE and HLF HCC cell lines for cytostatic TGF-β effects. In our cohort of 140 HCC patients, Smad7 transcripts were elevated in 41.4% of HCC samples as compared with adjacent tissue, with significant positive correlation to tumour size, whereas low Smad7 expression levels were significantly associated with worse clinical outcome. Univariate and multivariate analyses indicate Smad7 levels as an independent predictor for overall (P<0.001) and disease-free survival (P=0.0123). Delineating a mechanism for Smad7 transcriptional regulation in HCC, we identified cold-shock Y-box protein-1 (YB-1), a multifunctional transcription factor. YB-1 RNAi reduced TGF-β-induced and endogenous Smad7 expression in Huh7 and FLC-4 cells respectively. YB-1 and Smad7 mRNA expression levels correlated positively (P<0.0001). Furthermore, nuclear co-localization of Smad7 and YB-1 proteins was present in cancer cells of those patients. In summary, the present study provides a YB-1/Smad7-mediated mechanism that interferes with anti-proliferative/tumour-suppressive TGF-β actions in a subgroup of HCC cells that may facilitate aspects of tumour progression.
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MESH Headings
- Animals
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/metabolism
- Carcinoma, Hepatocellular/pathology
- Cell Line, Tumor
- Cell Proliferation
- Cells, Cultured
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Hep G2 Cells
- Hepatocytes/metabolism
- Humans
- Liver Diseases/genetics
- Liver Diseases/metabolism
- Liver Diseases/pathology
- Liver Neoplasms/genetics
- Liver Neoplasms/metabolism
- Liver Neoplasms/pathology
- Male
- Mice, 129 Strain
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Middle Aged
- Multivariate Analysis
- RNA Interference
- Reverse Transcriptase Polymerase Chain Reaction
- Smad7 Protein/genetics
- Smad7 Protein/metabolism
- Survival Analysis
- Transforming Growth Factor beta/pharmacology
- Y-Box-Binding Protein 1/genetics
- Y-Box-Binding Protein 1/metabolism
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Affiliation(s)
- Teng Feng
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Johanna Dzieran
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Xing Gu
- †Department of Laboratory Medicine, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
| | - Silke Marhenke
- ‡Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Hannover, Germany
| | - Arndt Vogel
- ‡Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Hannover, Germany
| | - Keigo Machida
- §Department of Molecular Microbiology and Immunology and Southern California Research Center for ALPD and Cirrhosis, Los Angeles, CA, U.S.A
| | - Thomas S Weiss
- ║Department of Pediatrics and Juvenile Medicine, Center for Liver Cell Research, University of Regensburg Hospital, Regensburg, Germany
| | - Petra Ruemmele
- ¶Institute of Pathology, University of Regensburg, Regensburg, Germany
| | - Otto Kollmar
- **Department of General, Visceral, Vascular and Pediatric Surgery, University of Saarland, Homburg/Saar, Germany
| | - Patrick Hoffmann
- ††Saarland University Medical School, Institute of Virology, Homburg/Saar, Germany
| | - Friedrich Grässer
- ††Saarland University Medical School, Institute of Virology, Homburg/Saar, Germany
| | - Heike Allgayer
- ‡‡Department of Experimental Surgery, University of Heidelberg, Mannheim and Molecular Oncology of Solid Tumors, DKFZ, Heidelberg, Germany
| | - Jasmin Fabian
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hong Lei Weng
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Andreas Teufel
- §§Klinik und Poliklinik für Innere Medizin I, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Thorsten Maass
- §§Klinik und Poliklinik für Innere Medizin I, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Christoph Meyer
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Ulrich Lehmann
- ║║Institute of Pathology, Medical School Hannover, Hannover, Germany
| | - Cheng Zhu
- ¶¶Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Peter R Mertens
- ¶¶Department of Nephrology and Hypertension, Diabetes and Endocrinology, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Chun Fang Gao
- †Department of Laboratory Medicine, Eastern Hepatobiliary Hospital, Second Military Medical University, Shanghai, China
| | - Steven Dooley
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Nadja M Meindl-Beinker
- *Molecular Hepatology Alcohol Associated Diseases, Dept. of Medicine II, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Effect of tetrandrine on the TGF-β-induced smad signal transduction pathway in human hypertrophic scar fibroblasts in vitro. Burns 2012; 38:404-13. [DOI: 10.1016/j.burns.2011.08.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/15/2011] [Accepted: 08/22/2011] [Indexed: 02/06/2023]
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Abstract
Transforming growth factor-β (TGF-β) is a central regulator in chronic liver disease contributing to all stages of disease progression from initial liver injury through inflammation and fibrosis to cirrhosis and hepatocellular carcinoma. Liver-damage-induced levels of active TGF-β enhance hepatocyte destruction and mediate hepatic stellate cell and fibroblast activation resulting in a wound-healing response, including myofibroblast generation and extracellular matrix deposition. Being recognised as a major profibrogenic cytokine, the targeting of the TGF-β signalling pathway has been explored with respect to the inhibition of liver disease progression. Whereas interference with TGF-β signalling in various short-term animal models has provided promising results, liver disease progression in humans is a process of decades with different phases in which TGF-β or its targeting might have both beneficial and adverse outcomes. Based on recent literature, we summarise the cell-type-directed double-edged role of TGF-β in various liver disease stages. We emphasise that, in order to achieve therapeutic effects, we need to target TGF-β signalling in the right cell type at the right time.
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Abstract
Abstract
Hepcidin is the master regulatory hormone of systemic iron metabolism. Hepcidin deficiency causes common iron overload syndromes whereas its overexpression is responsible for microcytic anemias. Hepcidin transcription is activated by the bone morphogenetic protein (BMP) and the inflammatory JAK-STAT pathways, whereas comparatively little is known about how hepcidin expression is inhibited. By using high-throughput siRNA screening we identified SMAD7 as a potent hepcidin suppressor. SMAD7 is an inhibitory SMAD protein that mediates a negative feedback loop to both transforming growth factor-β and BMP signaling and that recently was shown to be coregulated with hepcidin via SMAD4 in response to altered iron availability in vivo. We show that SMAD7 is coregulated with hepcidin by BMPs in primary murine hepatocytes and that SMAD7 overexpression completely abolishes hepcidin activation by BMPs and transforming growth factor-β. We identify a distinct SMAD regulatory motif (GTCAAGAC) within the hepcidin promoter involved in SMAD7-dependent hepcidin suppression, demonstrating that SMAD7 does not simply antagonize the previously reported hemojuvelin/BMP-responsive elements. This work identifies a potent inhibitory factor for hepcidin expression and uncovers a negative feedback pathway for hepcidin regulation, providing insight into a mechanism how hepcidin expression may be limited to avoid iron deficiency.
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Yang B, Zeng WZ, Wu XL. Advances in research on the signaling pathways involved in activation and phenotypic transformation of hepatic stellate cells and their inhibitors. Shijie Huaren Xiaohua Zazhi 2009; 17:2283-2291. [DOI: 10.11569/wcjd.v17.i22.2283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Liver fibrosis is a progressive pathologic process that involves deposition of excess extracellular matrix leading to distorted architecture and culminating in cirrhosis. It is believed that activation and phenotypic transformation of hepatic stellate cells (HSCs) play a central role in the development and resolution of liver fibrosis. Many cytokines and related signaling pathways are involved in the phenotypic transformation and proliferation of HSCs. In recent years, great advances have been made in the study of these signaling pathways and their specific inhibitors, thereby providing a new avenue for clinical therapy of liver fibrosis. However, as the mechanisms underlying the roles of these signaling pathways are very complicated, further intensive studies are still essential. In this article, we will review the advances in research on the signaling pathways involved in activation and phenotypic transformation of hepatic stellate cells and their inhibitors.
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Bai YT, Chen SF, Zheng H, Huang Q. Effects of interferon-alpha on the expression of Smad7 and PDGF-B in fibrotic pancreas in rats. Shijie Huaren Xiaohua Zazhi 2009; 17:2131-2136. [DOI: 10.11569/wcjd.v17.i21.2131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effects of interferon-alpha (IFN-α) on the expression of Smad7 and PDGF-B in fibrotic pancreas in rats with diethyldithiocarbamate (DDC)-induced pancreatic fibrosis.
METHODS: Three hundreds and twelve female Wistar rats were randomly divided into three groups: normal control group, model control group and IFN-α treatment group. Rats in the model control group and IFN-α treatment group were given repeated intraperitoneal injections of DDC to induce pancreatic fibrosis. Meanwhile, a subcutaneous injection of IFN-α was given to rats in the IFN-α treatment. The rats in the model control group were sacrificed at weeks 0, 1, 2, 4, 6 and 8 after initial induction with DDC, respectively, to take samples, while those in the IFN-α treatment group were sacrificed at week 6. The expression of Smad7 and PDGF-B in fibrotic pancreas were detected by immunohistochemistry.
RESULTS: Compared with the normal control group, the expression of Smad7 in the model control group began to decrease from week 3 (34.22 ± 7.60 vs 53.46 ± 30.45, P < 0.01) and was kept at low level from weeks 3 to 8, while the expression of PDGF-B in the model control group was high at the beginning (P < 0.01), gradually increased from weeks 3 to 7, and began to decrease from week 8. The expression level of Smad 7 at week 6 in the IFN-α treatment group was significantly higher than that in the model control group (47.22 ± 17.26 vs 15.27 ± 9.65, P < 0.01). In contrast, the expression level of PDGF-B at week 6 in the IFN-α treatment group was significantly lower than that in the model control group (29.13 ± 11.06 vs 57.63 ± 40.66, P < 0.01).
CONCLUSION: IFN-α is able to inhibit the expression of PDGF-B but promote the expression of Smad7 in fibrotic pancreas in rats.
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10
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Meindl-Beinker NM, Dooley S. Transforming growth factor-beta and hepatocyte transdifferentiation in liver fibrogenesis. J Gastroenterol Hepatol 2008; 23 Suppl 1:S122-7. [PMID: 18336655 DOI: 10.1111/j.1440-1746.2007.05297.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Currently, hepatic stellate cells (HSC) are thought to be the major fibrotic precursor cells that transdifferentiate to fibrogenic, extracellular matrix producing myofibroblasts in inflammatory liver tissue upon transforming growth factor-beta (TGF-beta) signaling, whereas hepatocytes are thought to respond with apoptosis to this cytokine. Starting out from in vitro experiments with primary hepatocyte cultures and immortalized AML-12 cells, TGF-beta signaling in this cell type was assessed and apoptosis was found to be only a minor effect. Instead, hepatocytes undergo epithelial mesenchymal transition (EMT), a physiological process in embryogenesis and of relevance for cancerous cell transformation. In injured liver, however, this process contributes to the promotion of fibrosis. Already after a few days of culture, hepatocytes lose their epithelial honeycomb-like shape towards a fibroblast-like phenotype. We could demonstrate by microarray analysis that stimulation of hepatocytes with TGF-beta regulates the expression of genes involved in EMT and fibrosis. Among these were, for example, Snail, a known mediator of EMT, and connective tissue growth factor (CTGF), a strong inducer of fibrosis. In a mouse model, hepatocyte-specific overexpression of Smad7 was able to blunt a fibrogenic response after CCl(4) intoxication. These results emphasize the dynamic nature of liver fibrosis, challenge the paradigm of HSC as a crucial source of liver myofibroblasts and hint towards a prominent role for hepatocytes in liver fibrogenesis.
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Affiliation(s)
- Nadja M Meindl-Beinker
- Molecular Alcohol Research in Gastroenterology, II, Medical Clinic, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
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11
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Hamzavi J, Ehnert S, Godoy P, Ciuclan L, Weng H, Mertens PR, Heuchel R, Dooley S. Disruption of the Smad7 gene enhances CCI4-dependent liver damage and fibrogenesis in mice. J Cell Mol Med 2008; 12:2130-44. [PMID: 18266971 PMCID: PMC4506177 DOI: 10.1111/j.1582-4934.2008.00262.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Transforming growth factor-beta (TGF-beta) signalling is induced in liver as a consequence of damage and contributes to wound healing with transient activation, whereas it mediates fibrogenesis with long-term up-regulation in chronic disease. Smad-dependent TGF-beta effects are blunted by antagonistic Smad7, which is transcriptionally activated as an immediate early response upon initiation of TGF-beta signalling in most cell types, thereby providing negative feedback regulation. Smad7 can be induced by other cytokines, e.g. IFN-gamma, leading to a crosstalk of these signalling pathways. Here we report on a novel mouse strain, denoted S7DeltaE1, with a deletion of exon I from the endogenous smad7 gene. The mice were viable and exhibited normal adult liver architecture. To obtain insight into Smad7-depend-ent protective effects, chronic liver damage was induced in mice by carbon tetrachloride (CCI4) administration. Subsequent treatment, elevated serum liver enzymes indicated enhanced liver damage in mice lacking functional Smad7. CCI4-dependent Smad2 phosphorylation was pronounced in S7DeltaE1 mice and accompanied by increased numbers of alpha-smooth muscle actin positive 'activated' HSCs. There was evidence for matrix accumulation, with elevated collagen deposition as assessed morphometrically in Sirius red stained tissue and confirmed with higher levels of hydroxyproline in S7DeltaE1 mice. In addition, the number of CD43 positive infiltrating lymphocytes as well as of apoptotic hepatocytes was increased. Studies with primary hepatocytes from S7DeltaE1 and wild-type mice indicate that in the absence of functional Smad7 protein, hepatocytes are more sensitive for TGF-beta effects resulting in enhanced cell death. Furthermore, S7DeltaE1 hepatocytes display increased oxidative stress and cell damage in response to CCI4, as measured by reactive oxygen species production, glutathione depletion, lactate dehydrogenase release and lipid peroxidation. Using an ALK-5 inhibitor all investigated CCI4 effects on hepatocytes were blunted, confirming participation of TGF-beta signalling. We conclude that Smad7 mediates a protective effect from adverse TGF-beta signalling in damaged liver, re-iterating its negative regulatory loop on signalling.
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Affiliation(s)
- Jafar Hamzavi
- Molecular Alcohol Research in Gastroenterology, Department of Medicine II, Faculty of Medicine at Mannheim, University of Heidelberg, Germany
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Joyner DE, Damron TA, Aboulafia AJ, Randall RL. Oncogene coexpression in mesenchymal neoplasia correlates with EGF transcription. Clin Orthop Relat Res 2007; 459:14-21. [PMID: 17414167 DOI: 10.1097/blo.0b013e318059b8b1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Epidermal growth factor (EGF) is a potent mitogenic factor for cells of mesodermal and ectodermal origin, and its over-expression is associated with a variety of cancers. We asked whether oncogene coexpression occurs in mesenchymal neoplasms, if coexpression correlates with EGF transcription, and whether coexpression can be attributed to the EGF-induced overexpression of oncogenes. We quantified the mRNA concentrations of EGF and 14 oncogenes in 42 primary sarcomas, 31 benign tumors, and 10 skeletal muscle controls, and compared mRNA concentrations and gene pair correlations in EGF positive (EGF+) tumors to transcript concentrations and correlations in EGF negative (EGF-) tumors. Transcripts were detected by real time reverse transcription-polymerase chain reaction. Pearson's correlation coefficients identified gene associations, and gene synchrony associated with EGF expression was evaluated using chi square. Transcript concentrations in tumors were compared graphically and with t tests. Gene correlations predominated in EGF+ benign tumors and in EGF- primary sarcomas. The dichotomy in oncogene coexpression evident in benign and malignant tumors could not be attributed to statistical differences in mRNA content between EGF+ and EGF- tumors. EGF may enhance, or may indicate the presence of, oncogene coexpression in benign mesenchymal lesions, but counters gene synchronization in sarcomas.
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Affiliation(s)
- David E Joyner
- Huntsman Cancer Institute, Department of Orthopaedics, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
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13
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Song SL, Gong ZJ, Huang YQ, Zhang QR, Huang TX. JinSanE decoction, a chinese herbal medicine, inhibits expression of TGF-beta1/Smads in experimental hepatic fibrosis in rats. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2007; 34:1047-61. [PMID: 17163593 DOI: 10.1142/s0192415x0600451x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The study is to investigate the effects of a Chinese herbal medicine, JinSanE decoction, on the TGF-beta1/Smads signal transduction pathway in a carbon tetrachloride (CCl(4))-induced hepatic fibrosis model in rats. Rats were randomly divided into 4 study groups: namely, a normal control group, a hepatic fibrosis model group, and 2 treatment groups with different doses of JinSanE (6 and 12 g/kg). Ten rats in each group were sacrificed at 4 and 8 weeks after exposure to CCl(4) respectively. The levels of TGF-beta1 and TRII mRNA in liver tissue were analyzed by RT-PCR. The expressions of TGF-beta1, Smad3 and Smad7 in liver tissues were evaluated by immunohistochemistry. The liver histopathology was examined by hematoxylin and eosin (HE) staining and electron microscopy respectively. The liver hydroxyproline (HYP), liver function and hyaluronic acid (HA) were examined by biochemistry and radioimmunoassay (RIA) respectively. Compared with the hepatic fibrosis model group, the levels of TGF-beta1, TRII mRNA and Smad3 expression significantly decreased in the 2 treatment groups. The expression of Smad7 was significantly increased in the liver of the rats treated with JinSanE (p < 0.05 or p < 0.01). The histological changes of fibrotic liver were obviously improved in the treatment rats. The levels of liver HYP, serum liver function and HA were also remarkably improved in the treatment rats. Moreover, the effects of JinSanE occurred in a dose- and time-dependent manner in the process of the protection of liver injury and fibrosis. JinSanE decoction had a protective effect on liver injury and could ameliorate hepatic fibrosis in rats. The mechanisms might be associated with their effects of down-regulating TGF-beta1, TRII mRNA and Smad3, and up-regulating Smad7.
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Affiliation(s)
- Shi-Ling Song
- State Key Laboratory of Virology, Department of Infectious Diseases, Renmin Hospital, Wuhan University, Wuhan 430060, China
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14
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Shen YM, Zhu X. Signal transduction and activation of hepatic stellate cells. Shijie Huaren Xiaohua Zazhi 2007; 15:873-878. [DOI: 10.11569/wcjd.v15.i8.873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Liver fibrosis, which leads to cirrhosis, occurs as a result of various injurious processes and it is the common pathologic basis of all the chronic hepatic diseases. At present, a good many researches demonstrate that the activation of hepatic stellate cells play a critical role in fibrogenesis. Prolonged liver injury results in hepatocyte damages and secretion of many fibrogenic cytokines such as transforming growth factor-beta 1, angiotensin, and leptin, which triggers the activation of hepatic stellate cells through different intracellular signal transduction pathways. In this article, we reviewed the research advancement in the signal transduction pathway of nuclear receptor and membrane receptor during the activation of hepatic stellate cells.
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Weng H, Mertens PR, Gressner AM, Dooley S. IFN-gamma abrogates profibrogenic TGF-beta signaling in liver by targeting expression of inhibitory and receptor Smads. J Hepatol 2007; 46:295-303. [PMID: 17125875 DOI: 10.1016/j.jhep.2006.09.014] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Revised: 08/29/2006] [Accepted: 09/09/2006] [Indexed: 01/18/2023]
Abstract
BACKGROUND/AIMS In a randomized open-labeled multicenter trial with patients suffering from chronic HBV infection, we recently identified a benefit of 9-month IFN-gamma treatment resulting in decreased fibrosis scores and a reduced number of alpha-smooth muscle actin-positive hepatic stellate cells (HSCs). Approaches opposing profibrogenic activities of TGF-beta may be amenable in chronic liver disease. According to experimental models, IFN-gamma counteracts several TGF-beta effects. METHODS The crosstalk of IFN-gamma and TGF-beta signaling relevant for fibrogenesis was investigated in primary cultured rat HSCs and a cell line representing activated HSCs. RESULTS In vitro studies with HSCs demonstrate that TGF-beta-dependent activation of (CAGA)9-MLP-Luc, a Smad3/4 responsive reporter construct, was significantly decreased by IFN-gamma, indicating a TGF-beta antagonizing function. IFN-gamma induced the activity of the Smad7 promoter and Smad7 protein expression via STAT-1 signaling. In contrast to TGF-beta, IFN-gamma was able to induce Smad7 expression in activated HSCs providing increased protein levels for at least 12h. In addition, expression of Smad2/3 was reduced by IFN-gamma and activation of Smads2/3 was abrogated. CONCLUSIONS IFN-gamma displays antifibrotic effects in liver cells via STAT-1 phosphorylation, upregulation of Smad7 expression and impaired TGF-beta signaling.
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Affiliation(s)
- Honglei Weng
- Institute of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, People's Republic of China
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Itman C, Loveland KL. SMAD expression in the testis: An insight into BMP regulation of spermatogenesis. Dev Dyn 2007; 237:97-111. [DOI: 10.1002/dvdy.21401] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Xu W, Song S, Huang Y, Gong Z. Effects of perindopril and valsartan on expression of transforming growth factor-beta-Smads in experimental hepatic fibrosis in rats. J Gastroenterol Hepatol 2006; 21:1250-6. [PMID: 16872305 DOI: 10.1111/j.1440-1746.2006.04331.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Previous studies have shown that the renin-angiotensin system (RAS) plays an important role in the pathogenesis of hepatic fibrosis, and blockers of the RAS may be active as an antifibrogenic goal. However, the potential role of RAS inhibition on expression transforming growth factor (TGF)-beta-Smads in hepatic fibrosis remains unknown. The aim of this study was to investigate the effect and mechanism of an angiotensin-converting enzyme inhibitor (perindopril) and an angiotensin II receptor blocker (valsartan) on TGF-beta1 and TGF receptor II (TRII) mRNA, Smad3 and Smad7 in fibrotic hepatic livers in rats. METHODS Sixty Wistar rats were randomly divided into four study groups (n = 15 for each group), including normal controls, hepatic fibrosis models, and two treated groups with either perindopril or valsartan, starting from the fourth week after being exposed to carbon tetrachloride (CCl(4)) for 4 weeks. The levels of TGF-beta and TRII mRNA in liver tissue were analyzed by RT-PCR. The expressions of TGF-beta1, Smad3 and Smad7 in liver tissues were evaluated by immunohistochemistry. The liver histopathology was examined by hematoxylin and eosin (HE) staining and by electron microscopy, respectively. The liver function and serum hyaluronic acid were also assayed by biochemistry and radioimmunoassay. RESULTS Compared with the hepatic fibrosis models, the levels of TGF-beta1, TRII mRNA and the expression Smad3 significantly decreased in the two treated groups, and the expression of Smad7 was significantly increased in the liver of rats treated with perindopril or valsartan (P < 0.05 or P < 0.01). The histological changes and ultrastructure of fibrotic liver, liver function and hyaluronic acid also remarkably improved in the treated rats. CONCLUSIONS The angiotensin-converting enzyme inhibitors perindopril and valsartan have a protective effect on liver injury and can ameliorate hepatic fibrosis in rats induced by CCl(4). The mechanisms may be associated with their effects of down-regulating TGF-beta1, TRII mRNA and smad3, and up-regulating Smad7.
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Affiliation(s)
- Wei Xu
- Department of Infectious Diseases, Renmin Hospital, State Key Laboratory of Virology, Wuhan University, Wuhan, China
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Wiercinska E, Wickert L, Denecke B, Said HM, Hamzavi J, Gressner AM, Thorikay M, ten Dijke P, Mertens PR, Breitkopf K, Dooley S. Id1 is a critical mediator in TGF-beta-induced transdifferentiation of rat hepatic stellate cells. Hepatology 2006; 43:1032-41. [PMID: 16628634 DOI: 10.1002/hep.21135] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transforming growth factor (TGF)-beta is critically involved in the activation of hepatic stellate cells (HSCs) that occurs during the process of liver damage, for example, by alcohol, hepatotoxic viruses, or aflatoxins. Overexpression of the TGF-beta antagonist Smad7 inhibits transdifferentiation and arrests HSCs in a quiescent stage. Additionally, bile duct ligation (BDL)-induced fibrosis is ameliorated by introducing adenoviruses expressing Smad7 with down-regulated collagen and alpha-smooth muscle actin (alpha-SMA) expression. The aim of this study was to further characterize the molecular details of TGF-beta pathways that control the transdifferentiation process. In an attempt to elucidate TGF-beta target genes responsible for fibrogenesis, an analysis of Smad7-dependent mRNA expression profiles in HSCs was performed, resulting in the identification of the inhibitor of differentiation 1 (Id1) gene. Ectopic Smad7 expression in HSCs strongly reduced Id1 mRNA and protein expression. Conversely, Id1 overexpression in HSCs enhanced cell activation and circumvented Smad7-dependent inhibition of transdifferentiation. Moreover, knock-down of Id1 in HSCs interfered with alpha-SMA fiber formation, indicating a pivotal role of Id1 for fibrogenesis. Treatment of HSCs with TGF-beta1 led to increased Id1 protein expression, which was not directly mediated by the ALK5/Smad2/3, but the ALK1/Smad1 pathway. In vivo, Id1 expression and Smad1 phosphorylation were co-induced during fibrogenesis. In conclusion, Id1 is identified as TGF-beta/ALK1/Smad1 target gene in HSCs and represents a critical mediator of transdifferentiation that might be involved in hepatic fibrogenesis. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).
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Affiliation(s)
- Eliza Wiercinska
- Molecular Alcohol Research in Gastroenterology, II. Medical Clinic, University Hospital Mannheim, University of Heidelberg, Germany
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Chen YW, Li DG, Wu JX, Chen YW, Lu HM. Tetrandrine inhibits activation of rat hepatic stellate cells stimulated by transforming growth factor-beta in vitro via up-regulation of Smad 7. JOURNAL OF ETHNOPHARMACOLOGY 2005; 100:299-305. [PMID: 15905052 DOI: 10.1016/j.jep.2005.03.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2004] [Revised: 03/02/2005] [Accepted: 03/10/2005] [Indexed: 05/02/2023]
Abstract
Tetrandrine is a bisbenzylisoquinoline alkaloid derived from the root of a Chinese herbal medicine Stephania tetrandra S. Moore, which has been used traditionally for the treatment of hepatofibrogenic disease in China for several decades. In the present study, the inhibitory effects of tetrandrine lower concentrations (0.25, 0.5, 1, 2 mg/L) on culture-activation and transforming growth factor-beta(1) (TGF-beta(1))-stimulated activation of quiescent rat hepatic stellate cells (HSCs) in vitro were assessed, and the possible relations between the underlying mechanism of these effects and TGF-beta signaling via its receptors were investigated. As shown by the examination of alpha-SMA using immunocytochemical staining or Western blot, tetrandrine inhibited both culture-activation and TGF-beta(1)-stimulated activation of HSCs. Further investigations revealed that, in this process, TGF-beta(1) mRNA expression was suppressed significantly in contrast to an up-regulation of Smad 7, while the expressions of type I and type II TGF-beta(1) receptors and Smad 3 mRNA were insignificantly changed by tetrandrine. These results suggest that tetrandrine at lower concentrations has a significant inhibiting effect on culture-activation and TGF-beta(1)-stimulated activation of rat HSCs, and that it may be due to an up-regulation of Smad 7 which in turn blocks TGF-beta(1) expression and its downstream signaling.
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Affiliation(s)
- Yuan-wen Chen
- Digestive Disease Laboratory, Xinhua Hospital, Shanghai Second Medical University, Shanghai 200092, PR China.
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20
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Song SL, Gong ZJ, Zhang QR, Huang TX. Effects of Chinese traditional compound, JinSanE, on expression of TGF-β1 and TGF-β1 type II receptor mRNA, Smad3 and Smad7 on experimental hepatic fibrosis in vivo. World J Gastroenterol 2005; 11:2269-76. [PMID: 15818738 PMCID: PMC4305811 DOI: 10.3748/wjg.v11.i15.2269] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: The transforming growth factor-beta (TGF-β)/Smad signaling pathway system plays a prominent role in the control of cell growth and extracellular matrix formation in the progression of liver fibrogenesis. Smad proteins can either positively or negatively regulate TGF-β responses. In this study, the therapeutic effects of Chinese traditional compound decoction, JinSanE, and the changes of TGF-β/Smad signaling pathway system in carbon tetrachloride (CCl4)-induced rat experimental liver fibrosis were examined.
METHODS: Seventy-two healthy Wistar rats were assigned to groups including normal control group, CCl4 model group, JinSanE treatment group I and JinSanE treatment group II. Each group contained 18 rats. All groups, except the normal control group, received CCl4 subcutaneous injection for 8 wk. Rats in JinSanE groups I and II were orally treated with JinSanE daily at the 1st and 5th wk, respectively, after exposure to CCl4. The expression of TGF-β1 and TGF-β1 type II receptor (TRII) mRNA in the liver was determined by reverse transcription polymerase chain reaction, and the expression of TGF-β1, Smad3 and Smad7 by immunohistochemistry. The liver histopathology was also examined by HE staining and observed under electron microscope. The activities of several serum fibrosis-associated enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), the levels of serum hyaluronic acid (HA) were assayed.
RESULTS: Hepatic fibrosis caused by CCl4 was significantly inhibited in the JinSanE-treated groups. The degrees of necrosis/degeneration and fibrosis scores were significantly lower in the JinSanE-treated groups than in the model control group. The expression of TGF-β1, TRII and Smad3 was significantly higher in the model group than that in the JinSanE-treated groups, and the active/total TGF-β1 ratio in the JinSanE groups was suppressed. Expression of TRII mRNA and Smad3 proteins showed a distribution pattern similar to that of TGF-β1 with a direct correlation in terms of the degree of hepatic fibrosis. The amount of positive staining Smad7 cells was significantly less in the model group than in the JinSanE-treated groups and the normal group. The contents of ALT, AST and HA were significantly lower in the JinSanE-treated groups than those in the model group.
CONCLUSION: Traditional Chinese medicine, JinSanE, prevents the progression of hepatic damage and fibrosis through the inhibition of TGF-β1, TRII and Smad3 signal proteins, and increases expression of Smad7 signal protein in vivo.
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Affiliation(s)
- Shi-Ling Song
- Department of Infectious Diseases, Renmin Hospital, Key Laboratory of Virology for Ministry of Education, Wuhan University, Wuhan 430060, Hubei Province, China
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21
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Lau MT, Ge W. Cloning of Smad2, Smad3, Smad4, and Smad7 from the goldfish pituitary and evidence for their involvement in activin regulation of goldfish FSHbeta promoter activity. Gen Comp Endocrinol 2005; 141:22-38. [PMID: 15707600 DOI: 10.1016/j.ygcen.2004.10.019] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2004] [Revised: 10/19/2004] [Accepted: 10/29/2004] [Indexed: 11/16/2022]
Abstract
Follicle-stimulating hormone (FSH), a glycoprotein consisting of an alpha subunit and a unique beta subunit, is essential for gonadal development and function in vertebrates including teleosts. FSH is regulated by a variety of neuroendocrine and endocrine factors, and its biosynthesis is primarily determined by the expression of the beta subunit. Although the regulation of FSH biosynthesis has been well documented in mammals, the molecular mechanisms underlying the regulation are poorly understood. Our previous studies demonstrated that activin stimulated goldfish FSHbeta expression in the primary pituitary cell culture and enhanced its promoter activity in the mouse gonadotrope cell line LbetaT-2 cells. However, little is known about the signal transduction pathway involved in the transcriptional activation of this gene by activin. To assess the involvement of intracellular signaling protein Smads in regulating goldfish FSHbeta promoter, we first cloned full-length cDNAs for goldfish Smad2, Smad3, Smad4, and Smad7 from the pituitary. All Smads cloned show high sequence conservation with their mammalian counterparts. The spatial expression of these Smads overlapped with that of activin subunits and its receptors in various tissues examined. In addition, we demonstrated that activin induced Smad3 and Smad7 expression, but not Smad2 and Smad4. Co-transfection of Smad2 or Smad3 cDNA into the LbetaT-2 cells with the reporter construct of goldfish FSHbeta promoter significantly enhanced basal and activin-stimulated reporter (SEAP, secreted alkaline phosphatase) expression, while Smad7 completely blocked basal and Smad2/3-stimulated FSHbeta activity. Interestingly, the effect of Smad3 was much higher than that of Smad2, suggesting that Smad3 is likely the principal signal transducing molecule involved in activin stimulation of FSHbeta expression in the goldfish. This work lays a foundation for further analysis of goldfish FSHbeta promoter for the cis-regulatory elements involved in activin signaling.
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Affiliation(s)
- Man-Tat Lau
- Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
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22
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Abstract
Alcohol abuse is a major cause of liver fibrosis and cirrhosis in developed countries. Before alcoholic liver fibrosis becomes evident, the liver undergoes several stages of alcoholic liver disease including steatosis and steatohepatitis. Although the main mechanisms of fibrogenesis are independent of the etiology of liver injury, alcoholic liver fibrosis is distinctively characterized by a pronounced inflammatory response due to elevated gut-derived endotoxin plasma levels, an augmented generation of oxidative stress with pericentral hepatic hypoxia and the formation of cell-toxic and profibrogenic ethanol metabolites (e.g. acetaldehyde or lipid oxidation products). These factors, based on a complex network of cytokine actions, together result in increased hepatocellular damage and activation of hepatic stellate cells, the key cell type of liver fibrogenesis. Although to date removal of the causative agent, i.e. alcohol, still represents the most effective intervention to prevent the manifestation of alcoholic liver disease, sophisticated molecular approaches are underway, aiming to specifically blunt profibrogenic signaling pathways in liver cells or specifically induce cell death in activated hepatic stellate cells to decrease the scarring of the liver.
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Affiliation(s)
- Soren V Siegmund
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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Johnson AL, Bridgham JT, Woods DC. Cellular Mechanisms and Modulation of Activin A- and Transforming Growth Factor β-Mediated Differentiation in Cultured Hen Granulosa Cells1. Biol Reprod 2004; 71:1844-51. [PMID: 15269104 DOI: 10.1095/biolreprod.104.032573] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Undifferentiated granulosa cells from prehierarchal (6- to 8-mm-diameter) hen follicles express very low to undetectable levels of LH receptor (LH-R) mRNA, P450 cholesterol side chain cleavage (P450scc) enzyme activity, and steroidogenic acute regulatory (StAR) protein, and produce negligible progesterone, in vitro, following an acute (3-h) challenge with either FSH or LH. It has previously been established that culturing such cells with FSH for 18-20 h induces LH-R, P450scc, and StAR expression, which enables the initiation of progesterone production. The present studies were conducted to characterize the ability of activin and transforming growth factor (TGF) beta, both alone and in combination with FSH, to promote hen granulosa cell differentiation, in vitro. A 20-h culture of prehierarchal follicle granulosa cells with activin A or transforming growth factor beta (TGFbeta)1 increased LH-R mRNA levels compared with control cultured cells. Activin A and TGFbeta1 also promoted FSH-receptor (FSH-R) mRNA expression when combined with FSH treatment. Neither activin A nor TGFbeta1 alone stimulated progesterone production after 20 h culture. However, preculture with either factor for 20 h (to induce gonadotropin receptor mRNA expression) followed by a 3-h challenge with FSH or LH potentiated StAR expression and progesterone production compared with cells challenged with gonadotropin in the absence of activin A or TGFbeta1 preculture. Significantly, activation of the mitogen-activated protein (MAP) kinase pathway with transforming growth factor alpha (TGFalpha) (monitored by Erk phosphorylation) blocked TGFbeta1-induced LH-R expression, and this effect was associated with the inhibition of Smad2 phosphorylation. We conclude that a primary differentiation-inducing action of activin A and TGFbeta1 on hen granulosa cells from prehierarchal follicles is directed toward LH-R expression. Enhanced LH-R levels subsequently sensitize granulosa cells to LH, which in turn promotes StAR plus P450scc expression and subsequently an increase in P4 production. Significantly, the finding that TGFbeta signaling is negatively regulated by MAP kinase signaling is proposed to represent a mechanism that prevents premature differentiation of granulosa cells.
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Affiliation(s)
- A L Johnson
- Department of Biological Sciences and Walther Cancer Center, The University of Notre Dame, Notre Dame, Indiana 46556, USA.
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Guéripel X, Benahmed M, Gougeon A. Sequential Gonadotropin Treatment of Immature Mice Leads to Amplification of Transforming Growth Factor β Action, Via Upregulation of Receptor-Type 1, Smad 2 and 4, and Downregulation of Smad 6. Biol Reprod 2004; 70:640-8. [PMID: 14585817 DOI: 10.1095/biolreprod.103.021162] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The present study was designed to establish the cellular localization and expression of transforming growth factor beta (TGFbeta) signaling pathway components, including TGFbeta1 and beta2; TGFbeta receptors type I (TbetaRI) and II (TbetaRII); and Smads 2, 3, 4, and 6 during gonadotropin-induced follicular maturation and ovulation in the mouse ovary. Immature 21-day-old mice were sequentially treated with recombinant human FSH, 5 IU daily for 3 days, and hCG once at Day 24 of life. Immunohistochemical experiments revealed a TGFbeta1 staining in granulosa cells (GC) and theca interna cells (TIC) as well as in oocytes, whereas that of TGFbeta2 was mainly localized in oocytes and GC. Strong immunostaining for both TbetaRI and -RII was observed in the TIC and, to a lesser extent, in GC. Whereas oocytes did not exhibit any staining for TbetaRII, their TbetaRI immunostaining was strong. Smads were detected in oocytes, GC, and luteal cells and in a lesser amount in TIC; the immunostaining for Smad 4 was the strongest. Western blotting and reverse transcription-polymerase chain reaction analyses indicated that, in response to gonadotropins, TGFbeta2, TbetaRI, Smad 2 and Smad 4 mRNA and protein levels increased, while those of Smad 6 decreased in ovarian homogenates. In conclusion, these results show that, in a model of immature mouse exposed to a sequential gonadotropin treatment, FSH and LH increased the expression of the TGFbeta signaling system through the increase of TGFbeta2, TbetaRI, stimulatory Smad 2, and common Smad 4 expression, which occurred concomitantly with a decrease of the inhibitory Smad 6 expression.
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Affiliation(s)
- Xavier Guéripel
- INSERM U-407, Faculté de Médecine Lyon-Sud, 69921 Oullins, France
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Li X, Ionescu AM, Schwarz EM, Zhang X, Drissi H, Puzas JE, Rosier RN, Zuscik MJ, O'Keefe RJ. Smad6 is induced by BMP-2 and modulates chondrocyte differentiation. J Orthop Res 2003; 21:908-13. [PMID: 12919880 DOI: 10.1016/s0736-0266(03)00008-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BMPs regulate cartilage differentiation and have been approved for clinical use as stimulators of bone repair. BMP signaling is complex and there are multiple potential points of regulation, including modulation of Smad signaling, which is inhibited by both Smad6 and Smad7. In the current manuscript we assessed the expression and biological function of Smad6 during chondrocyte differentiation. We found that the induction of chondrocyte differentiation by BMP-2 in chicken sternal embryonic chondrocytes was accompanied by a marked increase in Smad6 mRNA and protein levels. A morpholino antisense oligonucleotide complementary to Smad6 reduced the expression of Smad6 protein and enhanced the stimulatory effect of BMP-2 on both colX and alkaline phosphatase activity. In contrast, over-expression of Smad6 blocked BMP-2 mediated induction of the type X collagen promoter, b2-640 Luc. Therefore, expression studies as well as gain and loss of function experiments suggest that Smad6 participates in an important negative feedback loop whereby BMP-2 mediated effects on chondrocyte differentiation are reduced by induction of Smad6. Additional studies are required to determine the extent to which this pathway participates in pathologic processes involving cartilage.
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Affiliation(s)
- Xeufeng Li
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 665, Rochester, NY 14642, USA.
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Li X, Schwarz EM, Zuscik MJ, Rosier RN, Ionescu AM, Puzas JE, Drissi H, Sheu TJ, O'Keefe RJ. Retinoic acid stimulates chondrocyte differentiation and enhances bone morphogenetic protein effects through induction of Smad1 and Smad5. Endocrinology 2003; 144:2514-23. [PMID: 12746314 DOI: 10.1210/en.2002-220969] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Whereas bone morphogenetic protein (BMP)-signaling events induce maturational characteristics in vitro, recent evidence suggests that the effects of other regulators might be mediated through BMP-signaling events. The present study examines the mechanism through which retinoic acid (RA) stimulates differentiation in chicken embryonic caudal sternal chondrocyte cultures. Both RA and BMP-2 induced expression of the chondrocyte maturational marker, colX, in chondrocyte cultures by 8 d. Though the RA effect was small, it synergistically enhanced the effect of BMP-2 on colX and phosphatase activity. Inhibition of either RA or BMP signaling, with selective inhibitors, interfered with the inductive effects of these agents but also inhibited the complementary pathway, demonstrating a codependence of RA and BMP signaling during chondrocyte maturation. BMP-2 did not enhance the effects of RA on an RA-responsive reporter construct, but RA enhanced basal activity and synergistically enhanced BMP-2 stimulation of the BMP-responsive chicken type X collagen reporter. A similar synergistic interaction between RA and BMP-2 was observed on colX expression. RA did not increase the expression of the type IA BMP receptor but did markedly up-regulate the expression of Smad1 and Smad5 proteins, important participants in the BMP pathway. Inhibition of RA signaling, with the selective inhibitor AGN 193109, blocked RA-mediated induction of the Smad proteins and chondrocyte differentiation. These findings demonstrate that RA induces the expression of BMP-signaling molecules and enhances BMP effects in chondrocytes.
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Affiliation(s)
- Xuefeng Li
- Center for Musculoskeletal Research, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, USA
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Liu C, Gaça MDA, Swenson ES, Vellucci VF, Reiss M, Wells RG. Smads 2 and 3 are differentially activated by transforming growth factor-beta (TGF-beta ) in quiescent and activated hepatic stellate cells. Constitutive nuclear localization of Smads in activated cells is TGF-beta-independent. J Biol Chem 2003; 278:11721-8. [PMID: 12547835 DOI: 10.1074/jbc.m207728200] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Hepatic stellate cells are the primary cell type responsible for matrix deposition in liver fibrosis, undergoing a process of transdifferentiation into fibrogenic myofibroblasts. These cells, which undergo a similar transdifferentiation process when cultured in vitro, are a major target of the profibrogenic agent transforming growth factor-beta (TGF-beta). We have studied activation of the TGF-beta downstream signaling molecules Smads 2, 3, and 4 in hepatic stellate cells (HSC) cultured in vitro for 1, 4, and 7 days, with quiescent, intermediate, and fully transdifferentiated phenotypes, respectively. Total levels of Smad4, common to multiple TGF-beta superfamily signaling pathways, do not change as HSC transdifferentiate, and the protein is found in both nucleus and cytoplasm, independent of treatment with TGF-beta or the nuclear export inhibitor leptomycin B. TGF-beta mediates activation of Smad2 primarily in early cultured cells and that of Smad3 primarily in transdifferentiated cells. The linker protein SARA, which is required for Smad2 signaling, disappears with transdifferentiation. Additionally, day 7 cells demonstrate constitutive phosphorylation and nuclear localization of Smad 2, which is not affected by pretreatment with TGF-beta-neutralizing antibodies, a type I TGF-beta receptor kinase inhibitor, or activin-neutralizing antibodies. These results demonstrate essential differences between TGF-beta-mediated signaling pathways in quiescent and in vitro transdifferentiated hepatic stellate cells.
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Affiliation(s)
- Chenghai Liu
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Kitamura Y, Ninomiya H. Smad expression of hepatic stellate cells in liver cirrhosis in vivo and hepatic stellate cell line in vitro. Pathol Int 2003; 53:18-26. [PMID: 12558865 DOI: 10.1046/j.1440-1827.2003.01431.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Smad expressions, signaling mediators of transforming growth factor-beta (TGF-beta) superfamily of cytokines, were investigated in paraffin-embedded tissue sections of liver cirrhosis due to the hepatitis C virus infection and in the hepatic stellate cell (HSC) line in vitro. Smad 2/3, 4 and 7 was expressed in the nucleus of the HSC in the cirrhotic liver, while the expression was weak in the non-cirrhotic liver. TGF-beta1 expression in the HSC of the cirrhotic liver was strong, while the expression was weak in the non-cirrhotic liver. In situ hybridization also demonstrated the Smad signalings in the HSC of the cirrhotic liver, which confirmed the results of the Smad expressions by immunohistochemistry. The HSC line showed a cytoplasmic and a weak nuclear expression of Smads without TGF-beta1 stimulation, while these cells showed a strong Smad expression in the nucleus by TGF-beta1 stimulation. Immunocytochemical assay demonstrated that the TGF-beta1 stimulation induced the increase of the Smad expressions and the decrease of the autocrine TGF-beta1 in the HSC line. In situ hybridization assay also demonstrated an increase of the Smad mRNA signalings by TGF-beta1 stimulation in vitro. These observations suggest that the Smad expressions increase in the nucleus of the HSC in the cirrhotic liver and that the TGF-beta1 stimulation induces the Smad expression.
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Affiliation(s)
- Yukisato Kitamura
- Second Department of Pathology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Japan.
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Itoh S, Itoh F, Goumans MJ, Ten Dijke P. Signaling of transforming growth factor-beta family members through Smad proteins. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:6954-67. [PMID: 11106403 DOI: 10.1046/j.1432-1327.2000.01828.x] [Citation(s) in RCA: 396] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Smads are pivotal intracellular nuclear effectors of transforming growth factor-beta (TGF-beta) family members. Ligand-induced activation of TGF-beta family receptors with intrinsic serine/threonine kinase activity trigger phosphorylation of receptor-regulated Smads (R-Smads), whereas Smad2 and Smad3 are phosphorylated by TGF-beta, and activin type I receptors, Smad1, Smad5 and Smad8, act downstream of BMP type I receptors. Activated R-Smads form heteromeric complexes with common-partner Smads (Co-Smads), e.g. Smad4, which translocate efficiently to the nucleus, where they regulate, in co-operation with other transcription factors, coactivators and corepressors, the transcription of target genes. Inhibitory Smads act in most cases in an opposite manner from R- and Co-Smads. Like other components in the TGF-beta family signaling cascade, Smad activity is intricately regulated. The multifunctional and context dependency of TGF-beta family responses are reflected in the function of Smads as signal integrators. Certain Smads are somatically mutated at high frequency in particular types of human cancers. Gene ablation of Smads in the mouse has revealed their critical roles during embryonic development. Here we review the latest advances in our understanding of the Smad mechanism of action and their in vivo functions.
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Affiliation(s)
- S Itoh
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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Hua X, Miller ZA, Benchabane H, Wrana JL, Lodish HF. Synergism between transcription factors TFE3 and Smad3 in transforming growth factor-beta-induced transcription of the Smad7 gene. J Biol Chem 2000; 275:33205-8. [PMID: 10973944 DOI: 10.1074/jbc.c000568200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Activation of transforming growth factor-beta (TGF-beta) receptors triggers phosphorylation of Smad2 and Smad3. After binding to Smad4, the complex enters the nucleus and interacts with other transcription factors to activate gene transcription. Unlike other Smads, Smad7 inhibits phosphorylation of Smad2 and Smad3, and its transcription is induced by TGF-beta, suggesting a negative feedback loop. Here, we show that TFE3 and Smad3 synergistically mediate TGF-beta-induced transcription from the Smad7 promoter by binding to an E-box and two adjacent Smad binding elements (SBEs), respectively. A precise 3-base pair spacer between one SBE and the E-box is essential. Previously, we showed that a similar arrangement between a SBE and an E-box of an element is essential for TGF-beta-dependent transcription of the plasminogen activator inhibitor-1 gene (PAI-1) and that TGF-beta-induced phosphorylation of Smad3 triggers its association with TFE3. Thus, TFE3-Smad3 response elements may represent a common target for TGF-beta-induced gene expression.
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Affiliation(s)
- X Hua
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA
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Stopa M, Anhuf D, Terstegen L, Gatsios P, Gressner AM, Dooley S. Participation of Smad2, Smad3, and Smad4 in transforming growth factor beta (TGF-beta)-induced activation of Smad7. THE TGF-beta response element of the promoter requires functional Smad binding element and E-box sequences for transcriptional regulation. J Biol Chem 2000; 275:29308-17. [PMID: 10887185 DOI: 10.1074/jbc.m003282200] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Smad7 has recently been identified as a player that antagonizes transforming growth factor beta (TGF-beta) signals by acting downstream of TGF-beta receptors. TGF-beta rapidly induces expression of Smad7 mRNA in a variety of cell types, suggesting participation in a negative feedback loop to control TGF-beta responses. We have previously described the genomic locus of rat Smad7 including the promoter region. Here we report polymerase chain reaction cloning of the corresponding promoter regions of human and murine Smad7 genes and functional characterization of the rat Smad7 promoter. Using transient transfection experiments of HepG2 cells, we identified the TGF-beta response element within a strongly conserved region, containing a perfect Smad binding element (SBE; GTCTAGAC). Performing electrophoretic mobility shift assay and cotransfection experiments, we were able to delineate DNA-binding complexes and identified Smad3, Smad4, and Smad2. Mutation of the SBE completely abolished TGF-beta inducibility of Smad7 in HepG2 cells, indicating that this sequence is necessary for TGF-beta-induced transcription. Furthermore, a 3-base pair adjacent E-box is additionally essential for TGF-beta-dependent promoter activation and an overlapping AP1 site is also involved. We conclude that regulation of Smad7 transcription by TGF-beta is mediated via a specific constellation of recognition motifs localized around the SBE, which is conserved in human, rat, and murine genes.
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Affiliation(s)
- M Stopa
- Institut für Klinische Chemie und Pathobiochemie, RWTH-Universitätsklinikum, 52074 Aachen, Germany
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Dooley S, Delvoux B, Lahme B, Mangasser-Stephan K, Gressner AM. Modulation of transforming growth factor beta response and signaling during transdifferentiation of rat hepatic stellate cells to myofibroblasts. Hepatology 2000; 31:1094-106. [PMID: 10796885 DOI: 10.1053/he.2000.6126] [Citation(s) in RCA: 206] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Activation of hepatic stellate cells (HSCs) is the key step in liver fibrogenesis. Increased transforming growth factor beta (TGF-beta) expression and extracellular matrix production in patients with hepatic fibrosis and experimental models of liver fibrogenesis support implication of TGF-beta in the pathogenesis of this disease. However, a causative role for TGF-beta during transdifferentiation of HSCs has not been delineated in molecular detail. Using a rat cell culture model of HSC transdifferentiation, we analyzed TGF-beta signal transduction and identified changes between stellate cells and their transdifferentiated phenotype. Fully transdifferentiated myofibroblasts, opposed to HSCs, were not inhibited in proliferation activity on treatment with TGF-beta1. Furthermore, stimulation of alpha2 (I) collagen and Smad7 messenger RNA (mRNA) expression by TGF-beta1 was achieved in stellate cells but not in myofibroblasts. Northern and Western blot analyses indicated significant expression of TGF-beta receptors I and II in both cell types. In contrast, [(125)I]-TGF-beta1 receptor affinity labeling displayed strongly reduced types I, II, and III receptor presentation at the cell surface of myofibroblasts. Moreover, myofibroblasts did not display DNA-binding SMAD proteins in electrophoretic mobility shift assays with a CAGA box. These data indicate that stellate cells are responsive to TGF-beta1 treatment and transduce a signal that may play an important role in liver fibrogenesis. Myofibroblasts display decreased availability of surface receptors for TGF-beta, which could be based on autocrine stimulation. However, lack of activated SMAD complexes with DNA-binding activity and absence of alpha2 (I) collagen transcription inhibition by latency-associated peptide (LAP)/anti-TGF-beta antibody raise the possibility of TGF-beta signaling independent receptor down-regulation in myofibroblasts.
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Affiliation(s)
- S Dooley
- Institute of Clinical Chemistry and Pathobiochemistry, RWTH-University Hospital, Aachen, Germany
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