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Hajiasgharzadeh K, Baradaran B. Cholinergic Anti-Inflammatory Pathway and the Liver. Adv Pharm Bull 2017; 7:507-513. [PMID: 29399541 PMCID: PMC5788206 DOI: 10.15171/apb.2017.063] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/08/2017] [Accepted: 11/17/2017] [Indexed: 01/06/2023] Open
Abstract
The hepatic vagus branches innervate the liver and serve an important role in liver-brain connection. It appears that brain modulates inflammatory responses by activation of vagal efferent fibers. This activation and subsequent acetylcholine releases from vagus nerve terminals leads to inhibition of inflammatory cytokines through α7 nicotinic acetylcholine receptors (α7nAChRs) which located on the surface of different cell types such as liver Kupffer cells. This protective role of vagus-α7nAChR axis in liver diseases has been shown in several experimental studies. On the other hand, accumulated evidence clearly demonstrate that, autonomic dysfunction which is reduced functioning of both vagal and sympathetic nervous system, occurs during chronic liver disease and is well-known complication of patients suffering from cirrhosis. This review describes the impact and significance of cholinergic anti-inflammatory pathway in the liver and discusses about its disease-related dysfunction on the progression of cirrhosis. Considering the fact that sepsis is major cause of death in cirrhotic patients, convergence of these findings, may lead to designing novel therapeutic strategies in the field of chronic liver diseases management involving selective drug targeting and electrical nerve stimulation.
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Affiliation(s)
| | - Behzad Baradaran
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Does hepatic vagus nerve modulate the progression of biliary fibrosis in rats? Auton Neurosci 2014; 185:67-75. [DOI: 10.1016/j.autneu.2014.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/23/2014] [Accepted: 07/12/2014] [Indexed: 01/28/2023]
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Ebrahimkhani MR, Neiman JAS, Raredon MSB, Hughes DJ, Griffith LG. Bioreactor technologies to support liver function in vitro. Adv Drug Deliv Rev 2014; 69-70:132-57. [PMID: 24607703 PMCID: PMC4144187 DOI: 10.1016/j.addr.2014.02.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/18/2014] [Accepted: 02/24/2014] [Indexed: 02/08/2023]
Abstract
Liver is a central nexus integrating metabolic and immunologic homeostasis in the human body, and the direct or indirect target of most molecular therapeutics. A wide spectrum of therapeutic and technological needs drives efforts to capture liver physiology and pathophysiology in vitro, ranging from prediction of metabolism and toxicity of small molecule drugs, to understanding off-target effects of proteins, nucleic acid therapies, and targeted therapeutics, to serving as disease models for drug development. Here we provide perspective on the evolving landscape of bioreactor-based models to meet old and new challenges in drug discovery and development, emphasizing design challenges in maintaining long-term liver-specific function and how emerging technologies in biomaterials and microdevices are providing new experimental models.
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Affiliation(s)
- Mohammad R Ebrahimkhani
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jaclyn A Shepard Neiman
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Micha Sam B Raredon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Linda G Griffith
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Gynepathology Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Li S. Role of the renin-angiotensin system in liver fibrosis. Shijie Huaren Xiaohua Zazhi 2013; 21:2151-2157. [DOI: 10.11569/wcjd.v21.i22.2151] [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
Hepatic fibrosis is characterized by progressive inflammation and deposition of extracellular matrix components. Several recent studies have demonstrated that the rennin-angiotensin system (RAS) plays a key role in hepatic fibrosis. In this review, we provide a comprehensive update of the role of the RAS in the pathogenesis of hepatic fibrosis. We will discuss the profibrotic mechanisms activated by the RAS. Studies that have utilized angiotensin receptor blockers and angiotensin-converting enzyme inhibitors to modulate the RAS to ameliorate hepatic fibrosis will also be discussed.
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Bona S, Filippin LI, Di Naso FC, de David C, Valiatti B, Isoppo Schaun M, Xavier RM, Marroni NP. Effect of antioxidant treatment on fibrogenesis in rats with carbon tetrachloride-induced cirrhosis. ISRN GASTROENTEROLOGY 2012; 2012:762920. [PMID: 22577570 PMCID: PMC3335177 DOI: 10.5402/2012/762920] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 12/28/2011] [Indexed: 01/01/2023]
Abstract
Aim. This study aimed to assess the antioxidant activity of quercetin (Q) in an experimental model of cirrhosis induced by CCl4 inhalation. Materials and Methods. We used 25 male Wistar rats (250 g) that were divided into 3 groups: control (CO), CCl4, and CCl4 + Q. The rats were subjected to CCl4 inhalation (2x/week) for 16 weeks, and they received phenobarbital in their drinking water at a dose of 0.3 g/dL as a P450 enzyme inducer. Q (50 mg/Kg) was initiated intraperitoneally at 10 weeks of inhalation and lasted until the end of the experiment. Statistical analysis was by ANOVA Student Newman-Keuls (mean ± SEM), and differences were considered statistically significant when P < 0.05. Results. After treatment with quercetin, we observed an improvement in liver complications, decreased fibrosis, as analyzed by picrosirius for the quantification of collagen, and decreased levels of matrix metalloproteinase 2 (MMP-2) compared with the CCl4 group. It also reduced oxidative stress, as confirmed by the decrease of substances reacting to thiobarbituric acid (TBARS), the increased activity of antioxidant enzymes, and the reduced glutathione ratio and glutathione disulfide (GSH/GSSG). Conclusion. We suggest that the use of quercetin might be promising as an antioxidant therapy in liver fibrosis.
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Affiliation(s)
- Silvia Bona
- Post-Graduation Medical Sciences Program, Medical School, Federal University of Rio Grande do Sul (UFRGS), 90035-903 Porto Alegre, RS, Brazil
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Munshi MK, Uddin MN, Glaser SS. The role of the renin-angiotensin system in liver fibrosis. Exp Biol Med (Maywood) 2011; 236:557-66. [PMID: 21508249 DOI: 10.1258/ebm.2011.010375] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatic fibrosis, which is characterized by progressive inflammation and deposition of extracellular matrix components, is a common response to chronic liver disease. Hepatic fibrogenesis is a dynamic process that involves several liver cell types including hepatic stellate cells and Kupffer cells. In addition, recent evidence indicates that bile duct epithelial cells (i.e. cholangiocytes) also participate in the progression of biliary fibrosis that is observed during chronic cholestatic liver diseases, such as primary sclerosing cholangitis. To date, there are no effective treatments for hepatic fibrosis. Several recent studies have demonstrated that the renin-angiotensin system (RAS) plays a key role in hepatic fibrosis. Therapies targeting the RAS may represent a promising paradigm for the prevention and treatment of hepatic fibrosis in the setting of chronic liver disease. In this review, we provide a comprehensive update on the role of RAS in the pathogenesis of hepatic fibrosis in both animal models and human studies. We will discuss the profibrotic mechanisms activated by the RAS and the cell types involved. Studies that have utilized angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors to modulate the RAS in order to ameliorate hepatic fibrosis will also be discussed. Although the cumulative evidence supports the potential for the use of ARBs and ACE inhibitors as treatment for hepatic fibrosis, extensive studies of the effectiveness of RAS therapeutics are necessary in patients with chronic liver disease.
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Affiliation(s)
- M Kamruzzman Munshi
- Department of Medicine, Division of Gastroenterology, Scott & White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, 76504, USA
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Abstract
Continued elucidation of the mechanisms of hepatic fibrosis has yielded a comprehensive and nuanced portrait of fibrosis progression and regression. The paradigm of hepatic stellate cell (HSC) activation remains the foundation for defining events in hepatic fibrosis and has been complemented by progress in a number of new areas. Cellular sources of extracellular matrix beyond HSCs have been identified. In addition, the role of chemokine, adipokine, neuroendocrine, angiogenic and NAPDH oxidase signaling in the pathogenesis of hepatic fibrosis has been uncovered, as has the contribution of extracellular matrix stiffness to fibrogenesis. There is also increased awareness of the contribution of innate immunity and greater understanding of the complexity of gene regulation in HSCs and myofibroblasts. Finally, both apoptosis and senescence have been recognized as orchestrated programs that eliminate fibrogenic cells during resolution of liver fibrosis. Ironically, the progress that has been made has highlighted the growing disparity between advances in the experimental setting and their translation into new diagnostic tools and treatments. As a result, focus is shifting towards overcoming key translational challenges in order to accelerate the development of new therapies for patients with chronic liver disease.
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Mann J, Chu DCK, Maxwell A, Oakley F, Zhu NL, Tsukamoto H, Mann DA. MeCP2 controls an epigenetic pathway that promotes myofibroblast transdifferentiation and fibrosis. Gastroenterology 2010; 138:705-14, 714.e1-4. [PMID: 19843474 PMCID: PMC2819585 DOI: 10.1053/j.gastro.2009.10.002] [Citation(s) in RCA: 298] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 09/29/2009] [Accepted: 10/07/2009] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Myofibroblast transdifferentiation generates hepatic myofibroblasts, which promote liver fibrogenesis. The peroxisome proliferator-activated receptor gamma (PPARgamma) is a negative regulator of this process. We investigated epigenetic regulation of PPARgamma and myofibroblast transdifferentiation. METHODS Chromatin immunoprecipitation (ChIP) assays assessed the binding of methyl-CpG binding protein 2 (MeCP2) to PPARgamma and chromatin modifications that silence this gene. MeCP2(-/y) mice and an inhibitor (DZNep) of the epigenetic regulatory protein EZH2 were used in the carbon tetrachloride model of liver fibrosis. Liver tissues from mice were assessed by histologic analysis; markers of fibrosis were measured by quantitative polymerase chain reaction (qPCR). Reverse transcription PCR detected changes in expression of the microRNA miR132 and its target, elongated transcripts of MeCP2. Myofibroblasts were transfected with miR132; PPARgamma and MeCP2 expressions were analyzed by qPCR or immunoblotting. RESULTS Myofibroblast transdifferentiation of hepatic stellate cells is controlled by a combination of MeCP2, EZH2, and miR132 in a relay pathway. The pathway is activated by down-regulation of miR132, releasing the translational block on MeCP2. MeCP2 is recruited to the 5' end of PPARgamma, where it promotes methylation by H3K9 and recruits the transcription repressor HP1alpha. MeCP2 also stimulates expression of EZH2 and methylation of H3K27 to form a repressive chromatin structure in the 3' exons of PPARgamma. Genetic and pharmacologic disruptions of MeCP2 or EZH2 reduced the fibrogenic characteristics of myofibroblasts and attenuated fibrogenesis. CONCLUSIONS Liver fibrosis is regulated by an epigenetic relay pathway that includes MeCP2, EZH2, and miR132. Reagents that interfere with this pathway might be developed to reduce fibrogenesis in chronic liver disease.
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Affiliation(s)
- Jelena Mann
- Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.
| | - David CK Chu
- The University of Georgia College of Pharmacy, Athens, GA 30602, USA
| | - Aidan Maxwell
- Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, Cookson Building, Newcastle University, Framlington Place, Newcastle upon Tyne, NE24HH, UK
| | - Fiona Oakley
- Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, Cookson Building, Newcastle University, Framlington Place, Newcastle upon Tyne, NE24HH, UK
| | - Nian-Ling Zhu
- Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, University of Southern California Keck School of Medicine; and Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Hidekazu Tsukamoto
- Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, University of Southern California Keck School of Medicine; and Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Derek A Mann
- Institute of Cellular Medicine, Faculty of Medical Sciences, 4th Floor, Cookson Building, Newcastle University, Framlington Place, Newcastle upon Tyne, NE24HH, UK
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Abstract
Cholangiocyte proliferation is triggered during extrahepatic bile duct obstruction induced by bile duct ligation, which is a common in vivo model used for the study of cholangiocyte proliferation and liver fibrosis. The proliferative response of cholangiocytes during cholestasis is regulated by the complex interaction of several factors, including gastrointestinal hormones, neuroendocrine hormones and autocrine or paracrine signalling mechanisms. Activation of biliary proliferation (ductular reaction) is thought to have a key role in the initiation and progression of liver fibrosis. The first part of this review provides an overview of the primary functions of cholangiocytes in terms of secretin-stimulated bicarbonate secretion--a functional index of cholangiocyte growth. In the second section, we explore the important regulators, both inhibitory and stimulatory, that regulate the cholangiocyte proliferative response during cholestasis. We discuss the role of proliferating cholangiocytes in the induction of fibrosis either directly via epithelial mesenchymal transition or indirectly via the activation of other liver cell types. The possibility of targeting cholangiocyte proliferation as potential therapy for reducing and/or preventing liver fibrosis, and future avenues for research into how cholangiocytes participate in the process of liver fibrogenesis are described.
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