1
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Deng JW, Yang Q, Cai XP, Zhou JM, E WG, An YD, Zheng QX, Hong M, Ren YL, Guan J, Wang G, Lai SJ, Chen Z. Early use of dexamethasone increases Nr4a1 in Kupffer cells ameliorating acute liver failure in mice in a glucocorticoid receptor-dependent manner. J Zhejiang Univ Sci B 2021; 21:727-739. [PMID: 32893529 DOI: 10.1631/jzus.b2000249] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND OBJECTIVE Acute liver failure (ALF) is a type of disease with high mortality and rapid progression with no specific treatment methods currently available. Glucocorticoids exert beneficial clinical effects on therapy for ALF. However, the mechanism of this effect remains unclear and when to use glucocorticoids in patients with ALF is difficult to determine. The purpose of this study was to investigate the specific immunological mechanism of dexamethasone (Dex) on treatment of ALF induced by lipopolysaccharide (LPS)/D-galactosamine (D-GaIN) in mice. METHODS Male C57BL/6 mice were given LPS and D-GaIN by intraperitoneal injection to establish an animal model of ALF. Dex was administrated to these mice and its therapeutic effect was observed. Hematoxylin and eosin (H&E) staining was used to determine liver pathology. Multicolor flow cytometry, cytometric bead array (CBA) method, and next-generation sequencing were performed to detect changes of messenger RNA (mRNA) in immune cells, cytokines, and Kupffer cells, respectively. RESULTS A mouse model of ALF can be constructed successfully using LPS/D-GaIN, which causes a cytokine storm in early disease progression. Innate immune cells change markedly with progression of liver failure. Earlier use of Dex, at 0 h rather than 1 h, could significantly improve the progression of ALF induced by LPS/D-GaIN in mice. Numbers of innate immune cells, especially Kupffer cells and neutrophils, increased significantly in the Dex-treated group. In vivo experiments indicated that the therapeutic effect of Dex is exerted mainly via the glucocorticoid receptor (Gr). Sequencing of Kupffer cells revealed that Dex could increase mRNA transcription level of nuclear receptor subfamily 4 group A member 1 (Nr4a1), and that this effect disappeared after Gr inhibition. CONCLUSIONS In LPS/D-GaIN-induced ALF mice, early administration of Dex improved ALF by increasing the numbers of innate immune cells, especially Kupffer cells and neutrophils. Gr-dependent Nr4a1 upregulation in Kupffer cells may be an important ALF effect regulated by Dex in this process.
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Affiliation(s)
- Jing-Wen Deng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Qin Yang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Xiao-Peng Cai
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Jia-Ming Zhou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Wei-Gao E
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yan-Dong An
- Becton, Dickinson and Company, Shanghai 200126, China
| | - Qiu-Xian Zheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Meng Hong
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Yan-Li Ren
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Jun Guan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Gang Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
| | - Shu-Jing Lai
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Zhi Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China
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Ricci A, Biancucci F, Magnani M, Menotta M. Transcriptomic profile of ataxia telangiectasia cells treated for 30 days with a low dose of dexamethasone. ALL LIFE 2021. [DOI: 10.1080/26895293.2021.1911863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Anastasia Ricci
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
| | - Federica Biancucci
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino “Carlo Bo”, Urbino, Italy
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3
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Zakeri N, Mirdamadi ES, Kalhori D, Solati-Hashjin M. Signaling molecules orchestrating liver regenerative medicine. J Tissue Eng Regen Med 2020; 14:1715-1737. [PMID: 33043611 DOI: 10.1002/term.3135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/06/2020] [Accepted: 09/09/2020] [Indexed: 12/19/2022]
Abstract
The liver is in charge of more than 500 functions in the human body, which any damage and failure to the liver can significantly compromise human life. Numerous studies are being carried out in regenerative medicine, as a potential driving force, toward alleviating the need for liver donors and fabrication of a 3D-engineered transplantable hepatic tissue. Liver tissue engineering brings three main factors of cells, extracellular matrix (ECM), and signaling molecules together, while each of these three factors tries to mimic the physiological state of the tissue to direct tissue regeneration. Signaling molecules play a crucial role in directing tissue fabrication in liver tissue engineering. When mimicking the natural in vivo process of regeneration, it is tightly associated with three main phases of differentiation, proliferation (progression), and tissue maturation through vascularization while directing each of these phases is highly regulated by the specific signaling molecules. The understanding of how these signaling molecules guide the dynamic behavior of regeneration would be a tool for further tailoring of bioengineered systems to help the liver regeneration with many cellular, molecular, and tissue-level functions. Hence, the signaling molecules come to aid all these phases for further improvements toward the clinical use of liver tissue engineering as the goal.
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Affiliation(s)
- Nima Zakeri
- BioFabrication Lab (BFL), Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Elnaz Sadat Mirdamadi
- BioFabrication Lab (BFL), Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Dianoosh Kalhori
- BioFabrication Lab (BFL), Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Mehran Solati-Hashjin
- BioFabrication Lab (BFL), Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
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4
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Ødegård J, Sondresen JE, Aasrum M, Tveteraas IH, Guren TK, Christoffersen T, Thoresen GH. Differential effects of epidermal growth factor (EGF) receptor ligands on receptor binding, downstream signalling pathways and DNA synthesis in hepatocytes. Growth Factors 2017; 35:239-248. [PMID: 29582692 DOI: 10.1080/08977194.2018.1453506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hepatocytes are responsive to mitogenic effects of several ligands acting via EGFR. Studying primary cultures of rat hepatocytes, we found that, as compared to EGF, HB-EGF had a markedly higher affinity of the EGFR, while AR and TGFα had lower affinity. HB-EGF was also more potent compared to the other growth factors regarding phosphorylation of EGFR, Shc, ERK1/2 and Akt. All ligands induced phosphorylation of ErbB2, indicating receptor heterodimerization. TGFα, despite having much lower receptor affinity, was about equally potent and efficacious as HB-EGF as a stimulator of DNA synthesis. In contrast, EGF had relatively high affinity but markedly lower efficacy in stimulation of DNA synthesis. The results suggest that amplifying and/or inhibitory mechanisms may modulate the mitogenic responses downstream of the initial signalling steps, and that this may affect the effects of the EGFR ligands differentially.
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Affiliation(s)
- J Ødegård
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - J E Sondresen
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - M Aasrum
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - I H Tveteraas
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
- b Department of Pharmacology , Oslo University Hospital , Oslo , Norway
| | - T K Guren
- c Department of Oncology , Oslo University Hospital , Oslo , Norway
| | - T Christoffersen
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
| | - G H Thoresen
- a Department of Pharmacology , Institute of Clinical Medicine, University of Oslo , Oslo , Norway
- d Department of Pharmaceutical Biosciences, School of Pharmacy , University of Oslo , Oslo , Norway
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5
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Scheving LA, Zhang X, Threadgill DW, Russell WE. Hepatocyte ERBB3 and EGFR are required for maximal CCl4-induced liver fibrosis. Am J Physiol Gastrointest Liver Physiol 2016; 311:G807-G816. [PMID: 27586651 PMCID: PMC5130544 DOI: 10.1152/ajpgi.00423.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 08/18/2016] [Indexed: 01/31/2023]
Abstract
Epidermal growth factor receptor (EGFR) and its ligands have been implicated in liver fibrosis. However, it has not been directly shown that hepatocellular genetic ablation of either this receptor tyrosine kinase or ERBB3, its interactive signaling partner, affects hepatic fibrosis. Carbon tetrachloride (CCl4)-induced liver fibrosis in hepatocyte-specific (HS) mouse models of EGFR and ERBB3 ablation was evaluated in both single gene knockouts and an HS-EGFR-ERBB3 double knockout (DKO). Loss of hepatocellular EGFR or ERBB3 did not impact cytochrome P450-2E1 expression, the extent of centrilobular injury, or the initial regenerative response, but it did diminish liver fibrosis induced by chronic intraperitoneal administration of CCl4 The reduction of liver fibrosis correlated with reduced α-smooth muscle actin expression. Maximal impact to fibrogenesis occurred in the ERBB3 and EGFR-ERBB3 DKO models, suggesting that EGFR-ERBB3 heterodimeric signaling in damaged hepatocytes may play a more important role in liver fibrosis than EGFR-EGFR homodimeric signaling. Immunohistochemical analyses of phospho-EGFR and phospho-ERBB3 isoforms revealed clear staining in hepatocytes, activated stellate cells, and macrophages. Our results support a role for the hepatocellular ERBB tyrosine kinases in fibrogenesis and suggest that pharmacologic inhibition of EGFR-ERBB3 signaling may reverse or retard hepatic fibrosis.
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Affiliation(s)
- Lawrence A. Scheving
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Xiuqi Zhang
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - David W. Threadgill
- 6Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas; and ,7Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas
| | - William E. Russell
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee; ,2Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee; ,3Digestive Disease Research Center, Vanderbilt University Medical Center, Nashville, Tennessee; ,4Vanderbilt Diabetes Center, Vanderbilt University Medical Center, Nashville, Tennessee; ,5Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee;
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6
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Dang R, Guo Y, Zhang L, Chen L, Yang R, Jiang P. Chronic stress and excessive glucocorticoid exposure both lead to altered Neuregulin-1/ErbB signaling in rat myocardium. Steroids 2016; 112:47-53. [PMID: 27133902 DOI: 10.1016/j.steroids.2016.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/21/2016] [Accepted: 04/22/2016] [Indexed: 11/20/2022]
Abstract
Exposure to chronic stress or excess glucocorticoids is associated with the development of depression and heart disease, but the underlying mechanisms remain equivocal. While recent evidence has indicated that Neuregulin-1 (NRG1) and its ErbB receptors play an essential role in cardiac function, much is still unknown concerning the biological link between NRG1/ErbB pathway and the stress-induced comorbidity of depression and cardiac dysfunction. Therefore, we examined the protein expression of NRG1 and ErbB receptors in the myocardium of rats following chronic unpredictable mild stress (CUMS) or rats treated with two different doses (0.2 and 2mg/kg/day, respectively) of dexamethasone (Dex). The stressed rats showed elevated expression of NRG1 and phosphorylated ErbB4 (pErbB4) in the myocardium, whereas ErbB2 and pErbB2 were inhibited. The lower dose of Dex enhanced myocardial NRG1/ErbB signaling, but as the dose is increased, while ErbB4 remained activated, the expression of ErbB2 and pErbB2 became compromised. Both CUMS and 2mg/kg of Dex suppressed the downstream Akt and ERK phosphorylation. Although the lower dose of Dex increased myocardial antiapoptotic Bcl-xl expression, a significant decrease of Bcl-xl expression was found in rats treated with the higher dose. Meanwhile, both CUMS and two different doses of Dex induced proapoptotic Bax level. Combined, our data firstly showed (mal)adaptive responses of NRG1/ErbB system in the stressed heart, indicating the potential involvement of NRG1/ErbB pathway in the stress-induced cardiac dysfunction.
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Affiliation(s)
- Ruili Dang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining 272000, China
| | - Yujin Guo
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining 272000, China
| | - Ling Zhang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining 272000, China
| | - Lei Chen
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha 410010, China
| | - Ranyao Yang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining 272000, China
| | - Pei Jiang
- Institute of Clinical Pharmacy & Pharmacology, Jining First People's Hospital, Jining Medical University, Jining 272000, China.
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7
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Zhang X, Shang-Guan Y, Ma J, Hu H, Wang L, Magdalou J, Chen L, Wang H. Mitogen-inducible gene-6 partly mediates the inhibitory effects of prenatal dexamethasone exposure on endochondral ossification in long bones of fetal rats. Br J Pharmacol 2016; 173:2250-62. [PMID: 27128203 DOI: 10.1111/bph.13506] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 04/05/2016] [Accepted: 04/18/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Prenatal exposure to dexamethasone slows down fetal linear growth and bone mineralization but the regulatory mechanism remains unknown. Here we assessed how dexamethasone regulates bone development in the fetus. EXPERIMENTAL APPROACH Dexamethasone (1 mg·kg(-1) ·day(-1) ) was injected subcutaneously every morning in pregnant rats from gestational day (GD)9 to GD20. Fetal femurs and tibias were harvested at GD20 for histological and gene expression analysis. Femurs of 12-week-old female offspring were harvested for microCT (μCT) measurement. Primary chondrocytes were treated with dexamethasone (10, 50, 250 and 1000 nM). KEY RESULTS Prenatal dexamethasone exposure resulted in accumulation of hypertrophic chondrocytes and delayed formation of the primary ossification centre in fetal long bone. The retardation was accompanied by reduced maturation of hypertrophic chondrocytes, decreased osteoclast number and down-regulated expression of osteocalcin and bone sialoprotein in long bone. In addition, the mitogen-inducible gene-6 (Mig6) and osteoprotegerin (OPG) expression were stimulated, and the receptor activator of NF-κB ligand (RANKL) expression was repressed. Moreover, dexamethasone activated OPG and repressed RANKL expression in both primary chondrocytes and primary osteoblasts, and the knockdown of Mig6 abolished the effect of dexamethasone on OPG expression. Further, μCT measurement showed loss of bone mass in femur of 12-week-old offspring with prenatal dexamethasone exposure. CONCLUSIONS AND IMPLICATIONS Prenatal dexamethasone exposure delays endochondral ossification by suppressing chondrocyte maturation and osteoclast differentiation, which may be partly mediated by Mig6 activation in bone. Bone development retardation in the fetus may be associated with reduced bone mass in later life.
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Affiliation(s)
- Xianrong Zhang
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Yangfan Shang-Guan
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jing Ma
- Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
| | - Hang Hu
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Linlong Wang
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Jacques Magdalou
- Faculté de Médicine, UMR 7561 CNRS-NancyUniversité, Vandoeuvre-lès-Nancy, France
| | - Liaobin Chen
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China.,Department of Orthopedic Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Hui Wang
- Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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8
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Scheving LA, Zhang X, Stevenson MC, Weintraub MA, Abbasi A, Clarke AM, Threadgill DW, Russell WE. Loss of hepatocyte ERBB3 but not EGFR impairs hepatocarcinogenesis. Am J Physiol Gastrointest Liver Physiol 2015; 309:G942-54. [PMID: 26492920 PMCID: PMC4683301 DOI: 10.1152/ajpgi.00089.2015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 10/18/2015] [Indexed: 01/31/2023]
Abstract
Epidermal growth factor receptor (EGFR) and ERBB3 have been implicated in hepatocellular carcinogenesis (HCC). However, it is not known whether altering the activity of either EGFR or ERBB3 affects HCC development. We now show that Egfr(Dsk5) mutant mice, which have a gain-of-function allele that increases basal EGFR kinase activity, develop spontaneous HCC by 10 mo of age. Their tumors show increased activation of EGFR, ERBB2, and ERBB3 as well as AKT and ERK1,2. Hepatocyte-specific models of EGFR and ERBB3 gene ablation were generated to evaluate how the loss of these genes affected tumor progression. Loss of either receptor tyrosine kinase did not alter liver development or regenerative liver growth following carbon tetrachloride injection. However, using a well-characterized model of HCC in which N-nitrosodiethylamine is injected into 14-day-old mice, we discovered that loss of hepatocellular ERBB3 but not EGFR, which occurred after tumor initiation, retarded liver tumor formation and cell proliferation. We found no evidence that this was due to increased apoptosis or diminished phosphatidylinositol-3-kinase activity in the ERBB3-null cells. However, the relative amount of phospho-STAT3 was diminished in tumors derived from these mice, suggesting that ERBB3 may promote HCC through STAT3 activation.
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Affiliation(s)
- Lawrence A. Scheving
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Xiuqi Zhang
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Mary C. Stevenson
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Michael A. Weintraub
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Annam Abbasi
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - Andrea M. Clarke
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee;
| | - David W. Threadgill
- 6Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas; and ,7Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas
| | - William E. Russell
- 1Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee; ,5Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee;
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Sarkar U, Rivera-Burgos D, Large EM, Hughes DJ, Ravindra KC, Dyer RL, Ebrahimkhani MR, Wishnok JS, Griffith LG, Tannenbaum SR. Metabolite profiling and pharmacokinetic evaluation of hydrocortisone in a perfused three-dimensional human liver bioreactor. Drug Metab Dispos 2015; 43:1091-9. [PMID: 25926431 DOI: 10.1124/dmd.115.063495] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/29/2015] [Indexed: 12/12/2022] Open
Abstract
Endotoxin lipopolysaccharide (LPS) is known to cause liver injury primarily involving inflammatory cells such as Kupffer cells, but few in vitro culture models are applicable for investigation of inflammatory effects on drug metabolism. We have developed a three-dimensional human microphysiological hepatocyte-Kupffer cell coculture system and evaluated the anti-inflammatory effect of glucocorticoids on liver cultures. LPS was introduced to the cultures to elicit an inflammatory response and was assessed by the release of proinflammatory cytokines, interleukin 6 and tumor necrosis factor α. A sensitive and specific reversed-phase-ultra high-performance liquid chromatography-quadrupole time of flight-mass spectrometry method was used to evaluate hydrocortisone disappearance and metabolism at near physiologic levels. For this, the systems were dosed with 100 nM hydrocortisone and circulated for 2 days; hydrocortisone was depleted to approximately 30 nM, with first-order kinetics. Phase I metabolites, including tetrahydrocortisone and dihydrocortisol, accounted for 8-10% of the loss, and 45-52% consisted of phase II metabolites, including glucuronides of tetrahydrocortisol and tetrahydrocortisone. Pharmacokinetic parameters, i.e., half-life, rate of elimination, clearance, and area under the curve, were 23.03 hours, 0.03 hour(-1), 6.6 × 10(-5) l⋅hour(-1), and 1.03 (mg/l)*h, respectively. The ability of the bioreactor to predict the in vivo clearance of hydrocortisone was characterized, and the obtained intrinsic clearance values correlated with human data. This system offers a physiologically relevant tool for investigating hepatic function in an inflamed liver.
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Affiliation(s)
- Ujjal Sarkar
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Dinelia Rivera-Burgos
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Emma M Large
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - David J Hughes
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Kodihalli C Ravindra
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Rachel L Dyer
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Mohammad R Ebrahimkhani
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - John S Wishnok
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Linda G Griffith
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
| | - Steven R Tannenbaum
- Department of Biological Engineering (U.S., D.R.-B., K.C.R., R.L.D., M.R.E., J.S.W., L.G.G., S.R.T.), Department of Chemistry (S.R.T.), and Department of Mechanical Engineering (L.G.G.), Massachusetts Institute of Technology, Cambridge, Massachusetts; and CN Bio Innovations, Oxford University Begbroke Science Park, Begbroke, Oxfordshire, United Kingdom (E.M.L., D.J.H.)
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Colvin ES, Ma HY, Chen YC, Hernandez AM, Fueger PT. Glucocorticoid-induced suppression of β-cell proliferation is mediated by Mig6. Endocrinology 2013; 154:1039-46. [PMID: 23384834 PMCID: PMC3578994 DOI: 10.1210/en.2012-1923] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glucocorticoids can cause steroid-induced diabetes or accelerate the progression to diabetes by creating systemic insulin resistance and decreasing functional β-cell mass, which is influenced by changes in β-cell function, growth, and death. The synthetic glucocorticoid agonist dexamethasone (Dex) is deleterious to functional β-cell mass by decreasing β-cell function, survival, and proliferation. However, the mechanism by which Dex decreases β-cell proliferation is unknown. Interestingly, Dex induces the transcription of an antiproliferative factor and negative regulator of epidermal growth factor receptor signaling, Mig6 (also known as gene 33, RALT, and Errfi1). We, therefore, hypothesized that Dex impairs β-cell proliferation by increasing the expression of Mig6 and thereby decreasing downstream signaling of epidermal growth factor receptor. We found that Dex induced Mig6 and decreased [(3)H]thymidine incorporation, an index of cellular replication, in mouse, rat, and human islets. Using adenovirally delivered small interfering RNA targeted to Mig6 in rat islets, we were able to limit the induction of Mig6 upon exposure to Dex, compared with islets treated with a control virus, and completely rescued the Dex-mediated impairment in replication. We demonstrated that both Dex and overexpression of Mig6 attenuated the phosphorylation of ERK1/2 and blocked the G(1)/S transition of the cell cycle. In conclusion, Mig6 functions as a molecular brake for β-cell proliferation during glucocorticoid treatment in β-cells, and thus, Mig6 may be a novel target for preventing glucocorticoid-induced impairments in functional β-cell mass.
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Affiliation(s)
- E Scott Colvin
- Department of Pediatrics and Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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11
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Wancket LM, Meng X, Rogers LK, Liu Y. Mitogen-activated protein kinase phosphatase (Mkp)-1 protects mice against acetaminophen-induced hepatic injury. Toxicol Pathol 2012; 40:1095-105. [PMID: 22623522 DOI: 10.1177/0192623312447551] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
c-Jun N-terminal kinase (JNK) activation promotes hepatocyte death during acetaminophen overdose, a common cause of drug-induced liver failure. While mitogen-activated protein kinase (MAPK) phosphatase (Mkp)-1 is a critical negative regulator of JNK MAPK, little is known about the role of Mkp-1 during hepatotoxicity. In this study, we evaluated the role of Mkp-1 during acute acetaminophen toxicity. Mkp-1⁺/⁺ and Mkp-1⁻/⁻ mice were dosed ip with vehicle or acetaminophen at 300 mg/kg (for mechanistic studies) or 400 mg/kg (for survival studies). Tissues were collected 1-6 hr post 300 mg/kg dosing to assess glutathione levels, organ damage, and MAPK activation. Mkp-1⁻/⁻ mice exhibited more rapid plasma clearance of acetaminophen than did Mkp-1⁺/⁺ mice, indicated by a quicker decline of plasma acetaminophen level. Moreover, Mkp-1⁻/⁻ mice suffered more severe liver injury, indicated by higher plasma alanine transaminase activity and more extensive centrilobular apoptosis and necrosis. Hepatic JNK activity in Mkp-1⁻/⁻ mice was higher than in Mkp-1⁺/⁺ mice. Finally, Mkp-1⁻/⁻ mice displayed a lower overall survival rate and shorter median survival time after dosing with 400 mg/kg acetaminophen. The more severe phenotype exhibited by Mkp-1⁻/⁻ mice indicates that Mkp-1 plays a protective role during acute acetaminophen overdose, potentially through regulation of JNK.
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Affiliation(s)
- Lyn M Wancket
- Department of Veterinary Bioscience, The Ohio State University College of Veterinary Medicine, Columbus, Ohio, USA
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12
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Sekiyama A, Gon Y, Terakado M, Takeshita I, Kozu Y, Maruoka S, Matsumoto K, Hashimoto S. Glucocorticoids enhance airway epithelial barrier integrity. Int Immunopharmacol 2011; 12:350-7. [PMID: 22210372 DOI: 10.1016/j.intimp.2011.12.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/25/2011] [Accepted: 12/06/2011] [Indexed: 12/22/2022]
Abstract
Asthma is a chronic inflammatory disorder of the airways, but its pathogenesis is incompletely understood. While asthma is a complex disease caused by multiple factors, epithelial barrier damage is a cardinal feature. Glucocorticoids (GCs) are the most effective anti-inflammatory drugs in the treatment of asthma. However, the effects of GCs on the airway epithelial barrier have not been evaluated. Epithelial barrier functions were evaluated in cultured human airway epithelial cell monolayers, Calu-3 and 16HBE. Then, the cells were treated with dexamethasone (Dex), fulticasone propionate (FP), or budesonide (BD) for 5 days. Permeability measured by transepithelial electrical resistance was increased by treatment with Dex, FP, and BD in a dose-dependent manner. Permeability to fluorescein isothiocyanate-labeled dextran was markedly reduced by these treatments. Immunocytostaining revealed that Dex treatment potentiated tight junction formation in these polarized epithelial cells. Knockdown of epidermal growth factor receptor (EGFR) by small interference RNA blunted the effects of Dex on barrier integrity. Although EGFR expression was not affected by Dex treatment, EGFR phosphorylation was enhanced in Dex-treated cells. This is suggesting that EGFR are important for this phenomenon. These findings suggest that GC inhalation therapy can improve epithelial barrier integrity and might contribute to the therapeutic effects of GCs for treating asthma.
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Affiliation(s)
- Akiko Sekiyama
- Division of Respiratory Medicine, Department of Internal Medicine, Nihon University School of Medicine, Tokyo, Japan
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13
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Liu B, Wang G, Yang J, Pan X, Yang Z, Zang L. Berberine inhibits human hepatoma cell invasion without cytotoxicity in healthy hepatocytes. PLoS One 2011; 6:e21416. [PMID: 21738655 PMCID: PMC3123339 DOI: 10.1371/journal.pone.0021416] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 06/01/2011] [Indexed: 12/04/2022] Open
Abstract
Conventional chemotherapy fails to cure metastatic hepatoma mainly due to its high hepatotoxicity. Many plant-derived agents have been accepted to effectively inhibit hepatoma cell invasion. However, the investigation that whether effectual plant-derived agents against invasive hepatoma cells exert unexpected cytotoxicity in healthy hepatocytes has been ignored. This study demonstrated that berberine exhibited significant cytotoxicity in HepG2 cells mainly through upregulation of reactive oxygen species (ROS) production but was ineffective in normal Chang liver cells. Berberine exerted anti-invasive effect on HepG2 cells through suppression of matrix metalloproteinase-9 (MMP-9) expression. Moreover, berberine could significantly inhibit the activity of PI3K-AKT and ERK pathways. Combination treatment of ERK pathway inhibitor PD98059 or AKT pathway inhibitor LY294002 and berberine could result in a synergistic reduction on MMP-9 expression along with an inhibition of cell invasion. Enhancement of ROS production by berberine had no influence on its suppressive effects on the activity of PI3K-AKT and ERK pathways, as well as MMP-9 expression and HepG2 cell invasion. In conclusion, our results suggest that berberine may be a potential alternative against invasive hepatoma cells through PI3K-AKT and ERK pathways-dependent downregulation of MMP-9 expression. This study also provides a previously neglected insight into the investigation of plant-derived agents-based therapy against tumor invasion with the consideration of damage to healthy cells.
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Affiliation(s)
- Bing Liu
- Department of Pharmacology, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Genshu Wang
- Department of Liver Surgery, the Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Jie Yang
- Department of Pharmacology, School of Pharmacy, Guangxi Medical University, Nanning, People's Republic of China
| | - Xuediao Pan
- Department of Pharmacology, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Zhicheng Yang
- Department of Pharmacology, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Linquan Zang
- Department of Pharmacology, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
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14
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Kimura M, Moteki H, Ogihara M. Inhibitory effects of dexamethasone on hepatocyte growth factor-induced DNA synthesis and proliferation in primary cultures of adult rat hepatocytes. J Pharmacol Sci 2011; 115:390-8. [PMID: 21350311 DOI: 10.1254/jphs.10302fp] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We investigated the effects of dexamethasone on hepatocyte growth factor (HGF)-induced DNA synthesis and proliferation in serum-free primary cultures of adult rat hepatocytes. Isolated hepatocytes were cultured at a density of 3.3 × 10(4) cells/cm(2) in Williams' medium E containing 5% newborn bovine serum and various concentrations of dexamethasone for 1, 2, and 3 h. After a 3-h attachment period, the medium was then changed, and cells were cultured in serum-free dexamethasone (10(-10) M)-containing Williams' medium E with or without glucocorticoid receptor antagonists. After addition of dexamethasone to the culture medium, the growth-stimulating effects of HGF (5 ng/mL) on the primary cultured hepatocytes were time- and dose-dependently inhibited. The mineralcorticoid aldosterone (10(-7) M) did not produce the same growth-inhibitory effects as dexamethasone (10(-8) M). The inhibitory effects of dexamethasone were reversed by treatment with the glucocorticoid-receptor antagonist mifepristone (RU486, 10(-6) M) or a monoclonal antibody against glucocorticoid receptor (100 ng/mL). In addition, the growth-inhibitory dose of dexamethasone did not affect HGF-induced receptor tyrosine kinase and extracellular signal-regulated kinase 2 phosphorylation. These results indicate that dexamethasone dose-dependently delays and inhibits HGF-induced DNA synthesis and proliferation through its own intracellular receptor in primary cultures of adult rat hepatocytes.
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Affiliation(s)
- Mitsutoshi Kimura
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Josai University, Sakado, Japan.
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15
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Dual in vitro effects of cortisol on cell turnover in the medaka esophagus via the glucocorticoid receptor. Life Sci 2011; 88:239-45. [DOI: 10.1016/j.lfs.2010.11.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 10/19/2010] [Accepted: 11/15/2010] [Indexed: 01/26/2023]
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16
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Kimura M, Moteki H, Ogihara M. Inhibitory Effects of Dexamethasone on Epidermal Growth Factor-Induced DNA Synthesis and Proliferation in Primary Cultures of Adult Rat Hepatocytes. Biol Pharm Bull 2011; 34:682-7. [DOI: 10.1248/bpb.34.682] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Mitsutoshi Kimura
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Josai University
| | - Hajime Moteki
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Josai University
| | - Masahiko Ogihara
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Josai University
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Mehta G, Williams CM, Alvarez L, Lesniewski M, Kamm RD, Griffith LG. Synergistic effects of tethered growth factors and adhesion ligands on DNA synthesis and function of primary hepatocytes cultured on soft synthetic hydrogels. Biomaterials 2010; 31:4657-71. [PMID: 20304480 DOI: 10.1016/j.biomaterials.2010.01.138] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2009] [Accepted: 01/27/2010] [Indexed: 01/01/2023]
Abstract
The composition, presentation, and spatial orientation of extracellular matrix molecules and growth factors are key regulators of cell behavior. Here, we used self-assembling peptide nanofiber gels as a modular scaffold to investigate how fibronectin-derived adhesion ligands and different modes of epidermal growth factor (EGF) presentation synergistically regulate multiple facets of primary rat hepatocyte behavior in the context of a soft gel. In the presence of soluble EGF, inclusion of dimeric RGD and the heparin binding domain from fibronectin (HB) increased hepatocyte aggregation, spreading, and metabolic function compared to unmodified gels or gels modified with a single motif, but unlike rigid substrates, gels failed to induce DNA synthesis. Tethered EGF dramatically stimulated cell aggregation and spreading under all adhesive ligand conditions and also preserved metabolic function. Surprisingly, tethered EGF elicited DNA synthesis on gels with RGD and HB. Phenotypic differences between soluble and tethered EGF stimulation of cells on peptide gels are correlated with differences in expression and phosphorylation the EGF receptor and its heterodimerization partner ErbB2, and activation of the downstream signaling node ERK1/2. These modular matrices reveal new facets of hepatocellular biology in culture and may be more broadly useful in culture of other soft tissues.
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Affiliation(s)
- Geeta Mehta
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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18
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Abstract
Increasingly, research suggests that for certain systems, animal models are insufficient for human toxicology testing. The development of robust, in vitro models of human toxicity is required to decrease our dependence on potentially misleading in vivo animal studies. A critical development in human toxicology testing is the use of human primary hepatocytes to model processes that occur in the intact liver. However, in order to serve as an appropriate model, primary hepatocytes must be maintained in such a way that they persist in their differentiated state. While many hepatocyte culture methods exist, the two-dimensional collagen "sandwich" system combined with a serum-free medium, supplemented with physiological glucocorticoid concentrations, appears to robustly maintain hepatocyte character. Studies in rat and human hepatocytes have shown that when cultured under these conditions, hepatocytes maintain many markers of differentiation including morphology, expression of plasma proteins, hepatic nuclear factors, phase I and II metabolic enzymes. Functionally, these culture conditions also preserve hepatic stress response pathways, such as the SAPK and MAPK pathways, as well as prototypical xenobiotic induction responses. This chapter will briefly review culture methodologies but will primarily focus on hallmark hepatocyte structural, expression and functional markers that characterize the differentiation status of the hepatocyte.
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Affiliation(s)
- Katy M Olsavsky Goyak
- Center for Molecular Toxicology & Carcinogenesis and Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, USA
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Kamat A, Ghosh PM, Glover RL, Zhu B, Yeh CK, Choudhury GG, Katz MS. Reduced expression of epidermal growth factor receptors in rat liver during aging. J Gerontol A Biol Sci Med Sci 2008; 63:683-92. [PMID: 18693222 DOI: 10.1093/gerona/63.7.683] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Proliferative responsiveness of hepatocytes to epidermal growth factor (EGF) declines during aging. The role of EGF receptors in mediating age-dependent changes of EGF-induced mitogenic signaling in liver remains incompletely understood. We assessed EGF receptor expression levels in whole liver specimens as well as in freshly isolated and cultured hepatocytes from young adult and senescent Fischer 344 male rats. Hepatic EGF receptor messenger RNA and protein levels, and the number of high- and low-affinity receptor binding sites, decreased with aging. Ligand-induced EGF receptor activation, determined by receptor dimerization and tyrosine phosphorylation, was reduced in old animals in parallel with the age-related decline in receptor expression. Stimulation of the extracellular signal-regulated kinase pathway by EGF was also attenuated in hepatocytes from old animals. Our results implicate decreased expression of EGF receptors as a key determinant of reduced mitogenic signaling responsive to EGF stimulation of liver during aging.
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Affiliation(s)
- Amrita Kamat
- Geriatric Research Education and Clinical Center (182), Audie L Murphy Division, South Texas Veterans Health Care System, San Antonio, TX 78229, USA.
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20
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Scheving LA, Stevenson MC, Zhang X, Russell WE. Cultured rat hepatocytes upregulate Akt and ERK in an ErbB-2-dependent manner. Am J Physiol Gastrointest Liver Physiol 2008; 295:G322-31. [PMID: 18535289 PMCID: PMC2519852 DOI: 10.1152/ajpgi.00597.2007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Epidermal growth factor (EGF) stimulates freshly plated adult hepatocytes to synthesize DNA, but only after they pass through a lag phase of 40 h following EGF exposure. The longer the cells are maintained, they become more responsive to EGF and the lag phase shortens. Maximal EGF-mediated stimulation of DNA synthesis requires the induction of ErbB2, which is not normally expressed in adult hepatocytes. We used immunological methods to demonstrate increased expression during culture of two gene families required for EGF to stimulate hepatocyte DNA synthesis: Akt and ERK 1/2. Both families showed hyperexpression in culture particularly when cells were exposed to insulin and EGF. Unlike CDK-2 and cyclin D1, integral mediators of the G1/S phase transition, ERK 1/2 and Akt appeared in the absence of EGF, particularly when insulin was present. This hyperexpression, which high concentrations of dexamethasone reversed, increased basal and growth factor-stimulated phosphorylation of Akt and ERK 1/2. Pharmacological blockade of phosphatidylinositol kinase suppressed the Akt increase whereas pharmacological blockade or small interfering RNA downregulation of ErbB2 inhibited both Akt and ERK 1/2 expression. All three Akt isoforms contributed to the increase in total Akt. EGF but not insulin specifically upregulated Akt 2 and 3. Since Akt and ERK 1/2 are also hyperexpressed in poorly differentiated hepatomas, their dysregulation in cancer may involve transcriptional mechanisms normally operative in cultured hepatocytes. We hypothesize that the induction and activation of ErbB2 increases the expression of these kinases, enhancing the responsiveness of hepatocytes to EGF as they adapt to culture.
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Affiliation(s)
- Lawrence A. Scheving
- Departments of Pediatrics, Division of Endocrinology and Cell and Developmental Biology, the Digestive Disease Research Center, the Vanderbilt Diabetes Center, and the Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Mary C. Stevenson
- Departments of Pediatrics, Division of Endocrinology and Cell and Developmental Biology, the Digestive Disease Research Center, the Vanderbilt Diabetes Center, and the Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Xiuqi Zhang
- Departments of Pediatrics, Division of Endocrinology and Cell and Developmental Biology, the Digestive Disease Research Center, the Vanderbilt Diabetes Center, and the Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - William E. Russell
- Departments of Pediatrics, Division of Endocrinology and Cell and Developmental Biology, the Digestive Disease Research Center, the Vanderbilt Diabetes Center, and the Vanderbilt Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
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