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Billerbeck E, de Jong Y, Dorner M, de la Fuente C, Ploss A. Animal models for hepatitis C. Curr Top Microbiol Immunol 2013; 369:49-86. [PMID: 23463197 DOI: 10.1007/978-3-642-27340-7_3] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hepatitis C remains a global epidemic. Approximately 3 % of the world's population suffers from chronic hepatitis C, which is caused by hepatitis C virus (HCV)-a positive sense, single-stranded RNA virus of the Flaviviridae family. HCV has a high propensity for establishing a chronic infection. If untreated chronic HCV carriers can develop severe liver disease including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Antiviral treatment is only partially effective, costly, and poorly tolerated. A prophylactic or therapeutic vaccine for HCV does not exist. Mechanistic studies of virus-host interactions, HCV immunity, and pathogenesis as well as the development of more effective therapies have been hampered by the lack of a suitable small animal model. Besides humans, chimpanzees are the only species that is naturally susceptible to HCV infection. While experimentation in these large primates has yielded valuable insights, ethical considerations, limited availability, genetic heterogeneity, and cost limit their utility. In search for more tractable small animal models, numerous experimental approaches have been taken to recapitulate parts of the viral life cycle and/or aspects of viral pathogenesis that will be discussed in this review. Exciting new models and improvements in established models hold promise to further elucidate our understanding of chronic HCV infection.
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Affiliation(s)
- Eva Billerbeck
- Center for the Study of Hepatitis C, The Rockefeller University, NY, USA
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53
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Rashid ST, Alexander GJM. Induced pluripotent stem cells: from Nobel Prizes to clinical applications. J Hepatol 2013; 58:625-9. [PMID: 23131523 DOI: 10.1016/j.jhep.2012.10.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 10/29/2012] [Accepted: 10/30/2012] [Indexed: 01/11/2023]
Abstract
Advances in basic hepatology have been constrained for many years by the inability to culture primary hepatocytes in vitro, until just over five years ago when the scientific playing field was changed beyond recognition with the demonstration that human skin fibroblasts could be reprogrammed to resemble embryonic cells. The reprogrammed cells, known as induced pluripotent stem cells (iPSCs), were then shown to have the capacity to re-differentiate into almost any human cell type, including hepatocytes. The unlimited number and isogenic nature of the cells that can be generated from tiny fragments of tissue have massive implications for the study of human liver diseases in vitro. Of more immediate clinical importance were recent data demonstrating precision gene therapy on patient specific iPSCs, which opens up the real and exciting possibility of autologous hepatocyte transplantation as a substitute for allogeneic whole liver transplantation, which has been an effective approach to end-stage liver disease, but one that has now been outstripped by demand. In this review, we describe the historical development, current technology and potential clinical applications of induced pluripotency, concluding with a perspective on possible future directions in this dynamic field.
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Affiliation(s)
- S Tamir Rashid
- Division of Gastroenterology and Hepatology, Department of Medicine, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0SZ, UK.
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54
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Affiliation(s)
- Aras N Mattis
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research University of California, San Francisco, San Francisco, CA, USA
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Abstract
Human induced pluripotent stem cells offer the possibility of generating unlimited quantities of cells for autologous transplantation. By correcting the genetic defect underlying Z-allele α₁-antitrypsin deficiency, we recently provided the first proof of principle for application of human induced pluripotent stem cells in the treatment of inherited genetic disorders. Several important safety concerns will need to be addressed before this can be translated into clinical practice.
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Affiliation(s)
- S Tamir Rashid
- Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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Sauer V, Siaj R, Stöppeler S, Bahde R, Spiegel HU, Köhler G, Zibert A, Schmidt HHJ. Repeated transplantation of hepatocytes prevents fulminant hepatitis in a rat model of Wilson's disease. Liver Transpl 2012; 18:248-59. [PMID: 22140056 DOI: 10.1002/lt.22466] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The outcome of consecutive hepatocyte transplants was explored in a rat model of Wilson's disease before the onset of fulminant hepatitis without preconditioning regimens. Rats received a high-copper diet in order to induce a rapid induction of liver failure. Sham-operated rats (15/15) developed jaundice and fulminant hepatitis, and they died within 4 weeks of first transplantation. Despite the continuation of a high dietary copper challenge, long-term survival was observed for a notable proportion of the transplanted animals (7/18). All survivors displayed normalized levels of hepatitis-associated serum markers and ceruloplasmin oxidase activity by posttransplant days 50 and 98, respectively. The liver copper concentrations, the liver histology, and the expression of marker genes were significantly restored within 4 months of transplantation in comparison with the control group. The high expression of a copper transporter gene (ATPase Cu++ transporting beta polypeptide) in the livers of the survivors indicated a high rate of repopulation by donor hepatocytes. Our data suggest that repeated cell transplantation can overcome the limitations of a single therapy session in rats with severe hepatic disease by functionally restoring the host liver without preconditioning.
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Affiliation(s)
- Vanessa Sauer
- Clinic for Transplantation Medicine, Mu¨nster University Clinic, Münster, Germany
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57
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Maurice N, Perlmutter DH. Novel treatment strategies for liver disease due to α1-antitrypsin deficiency. Clin Transl Sci 2012; 5:289-94. [PMID: 22686209 DOI: 10.1111/j.1752-8062.2011.00363.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Alpha1-antitrypsin (AT) deficiency is the most common genetic cause of liver disease in children and is also a cause of chronic hepatic fibrosis, cirrhosis, and hepatocellular carcinoma in adults. Recent advances in understanding how mutant AT molecules accumulate within hepatocytes and cause liver cell injury have led to a novel strategy for chemoprophylaxis of this liver disease. This strategy involves a class of drugs, which enhance the intracellular degradation of mutant AT and, because several of these drugs have been used safely in humans for other indications, the strategy can be moved immediately into clinical trials. In this review, we will also report on advances that provide a basis for several other strategies that could be used in the future for treatment of the liver disease associated with AT deficiency.
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Affiliation(s)
- Nicholas Maurice
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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58
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Rountree CB, Mishra L, Willenbring H. Stem cells in liver diseases and cancer: recent advances on the path to new therapies. Hepatology 2012; 55:298-306. [PMID: 22030746 PMCID: PMC3245372 DOI: 10.1002/hep.24762] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stem cells have potential for therapy of liver diseases, but may also be involved in the formation of liver cancer. Recently, the American Association for the Study of Liver Diseases Henry M. and Lillian Stratton Basic Research Single Topic Conference "Stem Cells in Liver Diseases and Cancer: Discovery and Promise" brought together a diverse group of investigators to define the status of research on stem cells and cancer stem cells in the liver and identify problems and solutions on the path to clinical translation. This report summarizes the outcomes of the conference and provides an update on recent research advances. Progress in liver stem cell research includes isolation of primary liver progenitor cells (LPCs), directed hepatocyte differentiation of primary LPCs and pluripotent stem cells, findings of transdifferentiation, disease-specific considerations for establishing a therapeutically effective cell mass, and disease modeling in cell culture. Tumor-initiating stem-like cells (TISCs) that emerge during chronic liver injury share the expression of signaling pathways, including those organized around transforming growth factor beta and β-catenin, and surface markers with normal LPCs. Recent investigations of the role of TISCs in hepatocellular carcinoma have provided insight into the transcriptional and post-transcriptional regulation of hepatocarcinogenesis. Targeted chemotherapies for TISC are in development as a means to overcome cellular resistance and mechanisms driving disease progression in liver cancer.
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Affiliation(s)
- C. Bart Rountree
- Department of Pediatrics and Pharmacology, Penn State College of Medicine, Hershey, PA,Corresponding authors: C. Bart Rountree, MD, Department of Pediatrics and Pharmacology, Penn State College of Medicine and Hershey Medical Center, 500 University Drive, H085, Hershey, PA 17033, Telephone: 717 531 5901, Fax: 717 531 0653, . Holger Willenbring, MD, PhD, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Department of Surgery, Division of Transplantation, University of California San Francisco, 35 Medical Center Way, RMB-900C, Campus Box 0665, San Francisco, CA 94143, Telephone: 415 476 2417, Fax: 415 514 2346,
| | - Lopa Mishra
- Department of Gastroenterology, Hepatology and Nutrition, MD Anderson Cancer Center, Houston, TX
| | - Holger Willenbring
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA,Department of Surgery, Division of Transplantation, University of California San Francisco, San Francisco, CA,Liver Center, University of California San Francisco, San Francisco, CA,Corresponding authors: C. Bart Rountree, MD, Department of Pediatrics and Pharmacology, Penn State College of Medicine and Hershey Medical Center, 500 University Drive, H085, Hershey, PA 17033, Telephone: 717 531 5901, Fax: 717 531 0653, . Holger Willenbring, MD, PhD, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Department of Surgery, Division of Transplantation, University of California San Francisco, 35 Medical Center Way, RMB-900C, Campus Box 0665, San Francisco, CA 94143, Telephone: 415 476 2417, Fax: 415 514 2346,
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