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Manzoor S, Khalid M, Idrees M. P2X4 receptors mediate induction of antioxidants, fibrogenic cytokines and ECM transcripts; in presence of replicating HCV in in vitro setting: An insight into role of P2X4 in fibrosis. PLoS One 2022; 17:e0259727. [PMID: 35594248 PMCID: PMC9122194 DOI: 10.1371/journal.pone.0259727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 03/02/2022] [Indexed: 11/19/2022] Open
Abstract
Background & aims
Major HCV infections lead to chronic hepatitis, which results in progressive liver disease including fibrosis, cirrhosis and eventually hepatocellular carcinoma (HCC). P2X4 and P2X7 are most widely distributed receptors on hepatocytes.
Methods
Full length P2X4 (1.7kb) (Rattus norvegicus) was sub cloned in mammalian expression vector pcDNA3.1+. Two stable cell lines 293T/P2X4 (experimental) and 293T/ NV or null vector (control) were established. Both cell lines were inoculated with high viral titers human HCV sera and control human sera. Successfully infected cells harvested on day 5 and day 9 of post infection were used for further studies.
Results
The results revealed a significant increase in gene expression of P2X4 on day 5 and day 9 Post -infection in cells infected with HCV sera compared with cells inoculated with control sera. Quantitative real time PCR analysis revealed that HO-1 was significantly upregulated in presence of P2X4 in HCV infected cells (P2X4/HCV) when compared with control NV/HCV cells. A significant decrease was observed in expression of Cu/ZnSOD in presence of P2X4 in HCV infected cells compared to control NV/HCV cells. However, expression of both antioxidants was observed unaltered in cells harvested on day 9 post infection. Gene expression of angiotensin II significantly increased in HCV infected cells in presence of P2X4 on day 5 and day 9 of post infection when compared with control NV/HCV cells. A significant increase in gene expression of TNF-α and TGF-β was observed in HCV infected cells in presence of P2X4 on day 9 post infection in comparison with control (NV/HCV cells). However, gene expression of adipokine leptin was not affected in both experimental (P2X4/HCV) and control (NV/HCV) groups on day 5 and day 9 of post infection. Extracellular matrix proteins, laminin and elastin genes expression also significantly increased in presence of P2X4 (HCV/P2X4) on day 9 of post-infection compared to control group NV/HCV cells.
Conclusion
In conclusion, these findings constitute the evidence that P2X4 receptors in the presence of HCV play a significant role in the regulation of key antioxidant enzymes (HO-1, Cu/ZnSOD), in the induction of proinflammatory. cytokine (TNF-α), profibrotic cytokine (TGF-β) vasoactive cytokine (angiotensin II). P2X4 also increases the expression of extracellular matrix proteins (laminin and elastin) in the presence of HCV.
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Affiliation(s)
- Sobia Manzoor
- Center of Excellence in Molecular Biology (CEMB), University of Punjab, Lahore, Pakistan
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Science and Technology (NUST), Islamabad, Pakistan
- * E-mail: ,
| | - Madiha Khalid
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Science and Technology (NUST), Islamabad, Pakistan
| | - Muhammad Idrees
- Center of Excellence in Molecular Biology (CEMB), University of Punjab, Lahore, Pakistan
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Romanelli RG, Vitiello G, Gitto S, Giudizi MG, Biagiotti R, Carraresi A, Vizzutti F, Laffi G, Almerigogna F. Characterization of lymphocyte subsets in ascitic fluid and peripheral blood of decompensated cirrhotic patients with chronic hepatitis C and alcoholic liver disease: A pivotal study. Int J Immunopathol Pharmacol 2021; 34:2058738420929587. [PMID: 32524881 PMCID: PMC7290250 DOI: 10.1177/2058738420929587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Hepatitis C virus and alcoholic liver disease are major causes of chronic liver diseases worldwide. Little is known about differences between chronic hepatitis C and alcoholic liver disease in terms of lymphocytes’ sub-population. Aim of the present study was to compare the sub-populations of lymphocytes in both ascitic compartment and peripheral blood in patients with decompensated liver cirrhosis due to chronic hepatitis C and alcoholic liver disease. Patients with decompensated liver cirrhosis due to hepatitis C virus or alcoholic liver disease evaluated from April 2014 to October 2016 were enrolled. Whole blood and ascitic fluid samples were stained with monoclonal antibodies specific for human TCRɑβ, TCRɣδ, CD3, CD4, CD8, CD19, CCR6, CD16, CD56, CD25, HLA-DR, Vɑ24. Sixteen patients with decompensated liver cirrhosis were recruited (9 with hepatitis C virus and 7 with alcoholic liver disease). In ascitic fluid, the percentage of both CD3+CD56− and CD3+CD56+iNKT cells resulted higher in hepatitis C virus patients than in alcoholic liver disease patients (1.82 ± 0.35% vs 0.70 ± 0.42% (p < 0.001) and 1.42 ± 0.35% vs 0.50 ± 0.30% (p < 0.001), respectively). Conversely, in peripheral blood samples, both CD3+CD56− and CD3+CD56+iNKT cells resulted significantly higher in alcoholic liver disease than in hepatitis C virus patients (4.70 ± 2.69% vs 1.50 ± 1.21% (p < 0.01) and 3.10 ± 1.76% vs 1.00 ± 0.70% (p < 0.01), respectively). Both elevation of iNKT cells in ascitic fluid and reduction in peripheral blood registered in hepatitis C virus but not in alcoholic liver disease patients might be considered indirect signals of tissutal translocation. In conclusion, we described relevant differences between the two groups. Alcoholic liver disease patients displayed lower number of CD3+CD4+ cells and a higher percentage of CD3−CD16+, Vα24+CD3+CD56− and Vα24+CD3+CD56+iNKT cells in ascitic fluid than hepatitis C virus positive subjects. Further studies might analyze the role of immune cells in the vulnerability toward infections and detect potential targets for new treatments especially for alcoholic liver disease patients.
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Affiliation(s)
- Roberto Giulio Romanelli
- Internal Medicine and Liver Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Gianfranco Vitiello
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Stefano Gitto
- Internal Medicine and Liver Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Maria Grazia Giudizi
- Immunoallergology Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Roberta Biagiotti
- Immunoallergology Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Alessia Carraresi
- Immunoallergology Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Francesco Vizzutti
- Internal Medicine and Liver Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giacomo Laffi
- Internal Medicine and Liver Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Fabio Almerigogna
- Immunoallergology Unit, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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Nielsen MC, Andersen MN, Grønbæk H, Damgaard Sandahl T, Møller HJ. Extracellular vesicle-associated soluble CD163 and CD206 in patients with acute and chronic inflammatory liver disease. Scand J Gastroenterol 2020; 55:588-596. [PMID: 32393080 DOI: 10.1080/00365521.2020.1759140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background: Extracellular vesicles (EVs) are implicated in intercellular communication in liver diseases. An EV-associated fraction of the macrophage biomarker soluble CD163, denoted EV-CD163, was recently identified. EV-CD163 may be released during later phases of the inflammatory response as opposed to the acute shedding of CD163 ectodomain (Ecto-CD163). Total sCD163 is a well-described biomarker in liver inflammation, and we investigated the distribution of CD163 fractions along with EV-associated soluble CD206 (EV-CD206) in patients with acute and chronic alcoholic liver inflammation.Methods: Patients with acute alcoholic hepatitis (AH) (n = 48) and alcoholic cirrhosis (AC) (n = 26) were enrolled. Patients with AH were followed for 30 days after diagnosis. Healthy blood donors (n = 30) served as a reference group. Fractions of sCD163 and sCD206 were separated using ExoQuick™ and measured by ELISA.Results: We demonstrated a possible EV-associated fraction of CD206 in plasma, correlating with levels of EV-CD163 (rs = 0.46, p < .001). The distribution of biomarker fractions was skewed toward EVs in chronic cirrhosis for both biomarkers (median: 35.8% EV-CD163, 58.8% EV-CD206) as compared to AH patients (median: 26.2% EV-CD163 p < .0001, 48.8% EV-CD206, p < .01). In AH patients, total sCD163 and Ecto-CD163 at inclusion were related to survival, whereas EV-CD163 was not.Conclusion: Extracellular vesicles of macrophage origin associated with membrane receptors CD163 and CD206 are present in liver disease. We observed a shift in the distribution towards an increased EV fraction in chronic liver cirrhosis. These data support that Ecto and EV fractions may be markers of different inflammatory processes, possibly resulting from a switch in macrophage phenotype.
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Affiliation(s)
| | - Morten Nørgaard Andersen
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Henning Grønbæk
- Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Holger Jon Møller
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
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Dietrich CG, Götze O, Geier A. Molecular changes in hepatic metabolism and transport in cirrhosis and their functional importance. World J Gastroenterol 2016; 22:72-88. [PMID: 26755861 PMCID: PMC4698509 DOI: 10.3748/wjg.v22.i1.72] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 09/24/2015] [Accepted: 11/13/2015] [Indexed: 02/06/2023] Open
Abstract
Liver cirrhosis is the common endpoint of many hepatic diseases and represents a relevant risk for liver failure and hepatocellular carcinoma. The progress of liver fibrosis and cirrhosis is accompanied by deteriorating liver function. This review summarizes the regulatory and functional changes in phase I and phase II metabolic enzymes as well as transport proteins and provides an overview regarding lipid and glucose metabolism in cirrhotic patients. Interestingly, phase I enzymes are generally downregulated transcriptionally, while phase II enzymes are mostly preserved transcriptionally but are reduced in their function. Transport proteins are regulated in a specific way that resembles the molecular changes observed in obstructive cholestasis. Lipid and glucose metabolism are characterized by insulin resistance and catabolism, leading to the disturbance of energy expenditure and wasting. Possible non-invasive tests, especially breath tests, for components of liver metabolism are discussed. The heterogeneity and complexity of changes in hepatic metabolism complicate the assessment of liver function in individual patients. Additionally, studies in humans are rare, and species differences preclude the transferability of data from rodents to humans. In clinical practice, some established global scores or criteria form the basis for the functional evaluation of patients with liver cirrhosis, but difficult treatment decisions such as selection for transplantation or resection require further research regarding the application of existing non-invasive tests and the development of more specific tests.
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5
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Martínez-Esparza M, Tristán-Manzano M, Ruiz-Alcaraz AJ, García-Peñarrubia P. Inflammatory status in human hepatic cirrhosis. World J Gastroenterol 2015; 21:11522-11541. [PMID: 26556984 PMCID: PMC4631958 DOI: 10.3748/wjg.v21.i41.11522] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 07/31/2015] [Accepted: 09/30/2015] [Indexed: 02/06/2023] Open
Abstract
This review focuses on new findings about the inflammatory status involved in the development of human liver cirrhosis induced by the two main causes, hepatitis C virus (HCV) infection and chronic alcohol abuse, avoiding results obtained from animal models. When liver is faced to a persistent and/or intense local damage the maintained inflammatory response gives rise to a progressive replacement of normal hepatic tissue by non-functional fibrotic scar. The imbalance between tissue regeneration and fibrosis will determine the outcome toward health recovery or hepatic cirrhosis. In all cases progression toward liver cirrhosis is caused by a dysregulation of mechanisms that govern the balance between activation/homeostasis of the immune system. Detecting differences between the inflammatory status in HCV-induced vs alcohol-induced cirrhosis could be useful to identify specific targets for preventive and therapeutic intervention in each case. Thus, although survival of patients with alcoholic cirrhosis seems to be similar to that of patients with HCV-related cirrhosis (HCV-C), there are important differences in the altered cellular and molecular mechanisms implicated in the progression toward human liver cirrhosis. The predominant features of HCV-C are more related with those that allow viral evasion of the immune defenses, especially although not exclusively, inhibition of interferons secretion, natural killer cells activation and T cell-mediated cytotoxicity. On the contrary, the inflammatory status of alcohol-induced cirrhosis is determined by the combined effect of direct hepatotoxicity of ethanol metabolites and increases of the intestinal permeability, allowing bacteria and bacterial products translocation, into the portal circulation, mesenteric lymph nodes and peritoneal cavity. This phenomenon generates a stronger pro-inflammatory response compared with HCV-related cirrhosis. Hence, therapeutic intervention in HCV-related cirrhosis must be mainly focused to counteract HCV-immune system evasion, while in the case of alcohol-induced cirrhosis it must try to break the inflammatory loop established at the gut-mesenteric lymph nodes-peritoneal-systemic axis.
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6
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Houseman EA, Kelsey KT, Wiencke JK, Marsit CJ. Cell-composition effects in the analysis of DNA methylation array data: a mathematical perspective. BMC Bioinformatics 2015; 16:95. [PMID: 25887114 PMCID: PMC4392865 DOI: 10.1186/s12859-015-0527-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 03/05/2015] [Indexed: 11/10/2022] Open
Abstract
Background The impact of cell-composition effects in analysis of DNA methylation data is now widely appreciated. With the availability of a reference data set consisting of DNA methylation measurements on isolated cell types, it is possible to impute cell proportions and adjust for them, but there is increasing interest in methods that adjust for cell composition effects when reference sets are incomplete or unavailable. Results In this article we present a theoretical basis for one such method, showing that the total effect of a phenotype on DNA methylation can be decomposed into orthogonal components, one representing the effect of phenotype on proportions of major cell types, the other representing either subtle effects in composition or global effects at focused loci, and that it is possible to separate these two types of effects in a finite data set. We demonstrate this principle empirically on nine DNA methylation data sets, showing that the first few principal components generally contain a majority of the information on cell-type present in the data, but that later principal components nevertheless contain information about a small number of loci that may represent more focused associations. We also present a new method for determining the number of linear terms to interpret as cell-mixture effects and demonstrate robustness to the choice of this parameter. Conclusions Taken together, our work demonstrates that reference-free algorithms for cell-mixture adjustment can produce biologically valid results, separating cell-mediated epigenetic effects (i.e. apparent effects arising from differences in cell composition) from those that are not cell mediated, and that in general the interpretation of associations evident from DNA methylation should be carefully considered. Electronic supplementary material The online version of this article (doi:10.1186/s12859-015-0527-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- E Andres Houseman
- School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA.
| | - Karl T Kelsey
- Department of Epidemiology, Brown University School of Public Health, Providence, RI, USA.
| | - John K Wiencke
- Departments of Neurological Surgery, and Division of Epidemiology, University of California San Francisco, San Francisco, CA, USA.
| | - Carmen J Marsit
- Department of Community and Family Medicine, Dartmouth Medical School, Hanover, NH, USA.
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7
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Ju C, Mandrekar P. Macrophages and Alcohol-Related Liver Inflammation. Alcohol Res 2015; 37:251-62. [PMID: 26717583 PMCID: PMC4590621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Recent studies have suggested that macrophages have a critical role in the development of alcohol-induced inflammation in the liver. To define the precise pathogenic function of these cells during alcoholic liver disease (ALD), it is extremely important to conduct extensive studies in clinical settings that further elucidate the phenotypic diversity of macrophages In the context of ALD. Research to date already has identified several characteristics of macrophages that underlie the cells' actions, including macrophage polarization and their phenotypic diversity. Other analyses have focused on the contributions of resident versus infiltrating macrophages/monocytes, as well as on the roles of macrophage mediators, in the development of ALD. Findings point to the potential of macrophages as a therapeutic target in alcoholic liver injury. Future studies directed toward understanding how alcohol affects macrophage phenotypic switch in the liver and other tissues, whether the liver microenvironment determines macrophage function in ALO and if targeting of macrophages alleviates alcoholic liver injury, will provide promising strategies to manage patients with alcoholic hepatitis.
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8
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Ali L, Idrees M, Ali M, Hussain A, Ur Rehman I, Ali A, Iqbal SA, Kamel EH. Inhibitory effect of kaolin minerals compound against hepatitis C virus in Huh-7 cell lines. BMC Res Notes 2014; 7:247. [PMID: 24742271 PMCID: PMC3996148 DOI: 10.1186/1756-0500-7-247] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 04/04/2014] [Indexed: 01/18/2023] Open
Abstract
Background Hepatitis C virus (HCV) is estimated to infect 200 million individuals in the globe, including approximately 10 million in Pakistan causing both acute and chronic hepatitis. The standard treatment against HCV is pegylated interferon therapy in combination with a nucleoside analogue ribavirin. In addition, several herbal extracts and phytochemicals derivatives are used traditionally in the treatment of liver diseases as well as HCV infection. The present study determines the inhibitory effect of kaolin minerals compound against hepatitis C virus in Huh-7 cell lines. Methods Huh-7 cell lines were used for the in vitro HCV replication by using HCV positive sera from different patients with known HCV genotypes and viral titer/load. Total RNA was extracted from these infected cells and was quantified by real-time polymerase chain reaction (Real-time PCR). The viral titer was compared with the control samples to determine the anti-HCV activity of kaolin derived compounds. Kaolin is a group of clay minerals, with the chemical composition Al2 Si2O5 (OH)4. Results The results showed promising effectiveness of local kaolin derived anti-HCV compounds by causing 28% to 77% decrease in the HCV titer, when applied to infected Huh-7 cell lines. This study provides the basis for future work on these compounds especially to determine the specific pathway and mechanism for inhibitory action in the replicon systems of viral hepatitis. Conclusions Kaolin mineral derivatives show promising inhibitory effects against HCV genotypes 3a and 1a infection, which suggests its possible use as complementary and alternative medicine for HCV viral infection.
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Affiliation(s)
| | - Muhammad Idrees
- Division of Molecular Virology, National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, 87-West Canal bank Road, Thoker Niaz baig, Lahore 53700, Pakistan.
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Tapia-Abellán A, Martínez-Esparza M, Ruiz-Alcaraz AJ, Hernández-Caselles T, Martínez-Pascual C, Miras-López M, Such J, Francés R, García-Peñarrubia P. The peritoneal macrophage inflammatory profile in cirrhosis depends on the alcoholic or hepatitis C viral etiology and is related to ERK phosphorylation. BMC Immunol 2012; 13:42. [PMID: 22866973 PMCID: PMC3496568 DOI: 10.1186/1471-2172-13-42] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 07/24/2012] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The development of ascites in cirrhotic patients generally heralds a deterioration in their clinical status. A differential gene expression profile between alcohol- and hepatitis C virus (HCV)-related cirrhosis has been described from liver biopsies, especially those associated with innate immune responses. The aim of this work was to identify functional differences in the inflammatory profile of monocyte-derived macrophages from ascites in cirrhotic patients of different etiologies in an attempt to extrapolate studies from liver biopsies to immune cells in ascites. To this end 45 patients with cirrhosis and non-infected ascites, distributed according to disease etiology, HCV (n=15) or alcohol (n=30) were studied. Cytokines and the cell content in ascites were assessed by ELISA and flow cytometry, respectively. Cytokines and ERK phosphorylation in peritoneal monocyte-derived macrophages isolated and stimulated in vitro were also determined. RESULTS A different pattern of leukocyte migration to the peritoneal cavity and differences in the primed status of macrophages in cirrhosis were observed depending on the viral or alcoholic etiology. Whereas no differences in peripheral blood cell subpopulations could be observed, T lymphocyte, monocyte and polymorphonuclear cell populations in ascites were more abundant in the HCV than the alcohol etiology. HCV-related cirrhosis etiology was associated with a decreased inflammatory profile in ascites compared with the alcoholic etiology. Higher levels of IL-10 and lower levels of IL-6 and IL-12 were observed in ascitic fluid from the HCV group. Isolated peritoneal monocyte-derived macrophages maintained their primed status in vitro throughout the 24 h culture period. The level of ERK1/2 phosphorylation was higher in ALC peritoneal macrophages at baseline than in HCV patients, although the addition of LPS induced a greater increase in ERK1/2 phosphorylation in HCV than in ALC patients. CONCLUSIONS The macrophage inflammatory status is higher in ascites of alcohol-related cirrhotic patients than in HCV-related patients, which could be related with differences in bacterial translocation episodes or regulatory T cell populations. These findings should contribute to identifying potential prognostic and/or therapeutic targets for chronic liver diseases of different etiology.
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Affiliation(s)
- Ana Tapia-Abellán
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología Facultad de Medicina, Universidad de Murcia, Murcia, 30100, Spain
| | - María Martínez-Esparza
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología Facultad de Medicina, Universidad de Murcia, Murcia, 30100, Spain
| | - Antonio J Ruiz-Alcaraz
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología Facultad de Medicina, Universidad de Murcia, Murcia, 30100, Spain
| | - Trinidad Hernández-Caselles
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología Facultad de Medicina, Universidad de Murcia, Murcia, 30100, Spain
| | - Cristina Martínez-Pascual
- Unidad de Trasplante Hepático, Servicio de Aparato Digestivo, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain
| | - Manuel Miras-López
- Unidad de Trasplante Hepático, Servicio de Aparato Digestivo, Hospital Universitario Virgen de la Arrixaca, Murcia, Spain
| | - José Such
- Unidad Hepática, Hospital General Universitario, Alicante, Spain
- CIBERehd, Instituto de Salud Carlos III, Madrid, Spain
| | - Rubén Francés
- Unidad Hepática, Hospital General Universitario, Alicante, Spain
- CIBERehd, Instituto de Salud Carlos III, Madrid, Spain
| | - Pilar García-Peñarrubia
- Departamento de Bioquímica, Biología Molecular (B) e Inmunología Facultad de Medicina, Universidad de Murcia, Murcia, 30100, Spain
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Pang M, Bala S, Kodys K, Catalano D, Szabo G. Inhibition of TLR8- and TLR4-induced Type I IFN induction by alcohol is different from its effects on inflammatory cytokine production in monocytes. BMC Immunol 2011; 12:55. [PMID: 21962237 PMCID: PMC3203086 DOI: 10.1186/1471-2172-12-55] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 09/30/2011] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prolonged alcohol consumption is a significant co-factor in the progression of chronic viral infections including hepatitis C and HIV, which are both single-stranded RNA viruses. Toll like receptor 8 (TLR8), a pattern recognition receptor expressed in monocytes, senses viral single stranded RNA as a danger signal and leads to the induction of Type I interferon (IFN) as well as the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF alpha). Lipopolysaccharide (LPS), a Toll like receptor 4 (TLR4) ligand, was shown to affect inflammatory cell activation after alcohol consumption and in HIV and HCV infections. Here we hypothesized that alcohol exposure modulates TLR8- and TLR4-ligand-induced monocyte activation and affects both type I IFN and inflammatory cytokine induction. RESULTS The TLR8 ligand, CL075, as well as the TLR4 ligand, LPS, resulted in a significant induction of TNF alpha both at the mRNA and protein levels in human monocytes. We found that both acute and prolonged alcohol treatment resulted in inhibition of type I IFN induction by either TLR8 or TLR4 ligands in human monocytes at the protein and mRNA levels. In contrast to Type I IFN production, the effects of acute and prolonged alcohol were different on inflammatory cytokine activation after TLR8 or TLR4 ligand stimulation. Acute alcohol inhibited TLR8- or TLR4-induced TNF alpha protein and mRNA induction while it augmented IL-10 production in monocytes. In contrast, prolonged alcohol treatment augmented TNF alpha without affecting IL-10 production significantly in response to either TLR8 or TLR4 ligand stimulation. CONCLUSIONS These novel results suggest first, that alcohol has a profound inhibitory effect on Type I IFN induction regardless of intracellular (TLR8) or cell surface-derived (TLR4) danger signals. Second, both acute and prolonged alcohol exposure can inhibit antiviral Type I IFN pathway activation. Third, the opposite effects of acute (inhibitory) and prolonged alcohol (augmentation) treatment on pro-inflammatory cytokine activation extend to TLR8-induced signals beyond the previously shown TLR4/LPS pathway.
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Affiliation(s)
- Maoyin Pang
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA
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11
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Folkers ME, Delker DA, Maxwell CI, Nelson CA, Schwartz JJ, Nix DA, Hagedorn CH. ENCODE tiling array analysis identifies differentially expressed annotated and novel 5' capped RNAs in hepatitis C infected liver. PLoS One 2011; 6:e14697. [PMID: 21359205 PMCID: PMC3040182 DOI: 10.1371/journal.pone.0014697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 01/24/2011] [Indexed: 01/02/2023] Open
Abstract
Microarray studies of chronic hepatitis C infection have provided valuable
information regarding the host response to viral infection. However, recent
studies of the human transcriptome indicate pervasive transcription in
previously unannotated regions of the genome and that many RNA transcripts have
short or lack 3′ poly(A) ends. We hypothesized that using ENCODE tiling
arrays (1% of the genome) in combination with affinity purifying Pol II
RNAs by their unique 5′ m7GpppN cap would identify previously
undescribed annotated and unannotated genes that are differentially expressed in
liver during hepatitis C virus (HCV) infection. Both 5′-capped and
poly(A)+ populations of RNA were analyzed using ENCODE tiling arrays.
Sixty-four annotated genes were significantly increased in HCV cirrhotic as
compared to control liver; twenty-seven (42%) of these genes were
identified only by analyzing 5′ capped RNA. Thirty-one annotated genes
were significantly decreased; sixteen (50%) of these were identified only
by analyzing 5′ capped RNA. Bioinformatic analysis showed that capped RNA
produced more consistent results, provided a more extensive expression profile
of intronic regions and identified upregulated Pol II transcriptionally active
regions in unannotated areas of the genome in HCV cirrhotic liver. Two of these
regions were verified by PCR and RACE analysis. qPCR analysis of liver biopsy
specimens demonstrated that these unannotated transcripts, as well as IRF1,
TRIM22 and MET, were also upregulated in hepatitis C with mild inflammation and
no fibrosis. The analysis of 5′ capped RNA in combination with ENCODE
tiling arrays provides additional gene expression information and identifies
novel upregulated Pol II transcripts not previously described in HCV infected
liver. This approach, particularly when combined with new RNA sequencing
technologies, should also be useful in further defining Pol II transcripts
differentially regulated in specific disease states and in studying RNAs
regulated by changes in pre-mRNA splicing or 3′ polyadenylation
status.
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Affiliation(s)
- Milan E. Folkers
- Department of Medicine, University of Utah,
Salt Lake City, Utah, United States of America
| | - Don A. Delker
- Department of Medicine, University of Utah,
Salt Lake City, Utah, United States of America
- Huntsman Cancer Institute, University of Utah,
Salt Lake City, Utah, United States of America
| | - Christopher I. Maxwell
- Department of Medicine, University of Utah,
Salt Lake City, Utah, United States of America
- Huntsman Cancer Institute, University of Utah,
Salt Lake City, Utah, United States of America
| | - Cassie A. Nelson
- Department of Medicine, University of Utah,
Salt Lake City, Utah, United States of America
| | - Jason J. Schwartz
- Department of Surgery, University of Utah,
Salt Lake City, Utah, United States of America
| | - David A. Nix
- Huntsman Cancer Institute, University of Utah,
Salt Lake City, Utah, United States of America
| | - Curt H. Hagedorn
- Department of Medicine, University of Utah,
Salt Lake City, Utah, United States of America
- Huntsman Cancer Institute, University of Utah,
Salt Lake City, Utah, United States of America
- Department of Experimental Pathology,
University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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12
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Brown JR, Magid-Slav M, Sanseau P, Rajpal DK. Computational biology approaches for selecting host-pathogen drug targets. Drug Discov Today 2011; 16:229-36. [PMID: 21277381 DOI: 10.1016/j.drudis.2011.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 12/02/2010] [Accepted: 01/20/2011] [Indexed: 02/08/2023]
Abstract
The proliferation of genomic platform data, ranging from silencing RNAs through mRNA and microRNA expression to proteomics, is providing new insights into the interplay between human and pathogen genes during infection: the so-called 'host-pathogen interactome'. Exploiting the interactome for novel human drug targets could provide new therapeutic avenues towards the treatment of infectious disease, which could ameliorate the growing clinical challenge of drug-resistant infections. Using the hepatitis C virus interactome as an example, here we suggest a computational biology framework for identifying and prioritizing potential human host targets against infectious diseases.
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Affiliation(s)
- James R Brown
- Computational Biology, GlaxoSmithKline, 1250 South Collegeville Road, UP1345, PO Box 5089, Collegeville, PA 19426-0989, USA
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13
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Bergheim I, Eagon PK, Dooley S, Breitkopf-Heinlein K. Alcoholic liver disease and exacerbation by malnutrition and infections: what animal models are currently available? Ann N Y Acad Sci 2010; 1216:41-9. [PMID: 21182534 DOI: 10.1111/j.1749-6632.2010.05833.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Alcoholic liver disease remains a frequent and serious problem for increasing numbers of patients. Research has expanded our molecular understanding of the cellular basis of disease progression; however, translation into therapy is still hampered by a lack of suitable animal models for alcoholic liver disease, as well as from consequences of related liver damage due to malnutrition, hepatitis C virus infection, or abuse of other substances. Many patients with liver disease do not simply consume too much alcohol; they also suffer from comorbidities such as obesity or viral hepatitis, and/or may be addicted to other drugs besides alcohol. This review will summarize the currently available animal models to study liver disease due to either single causes or combinations of liver toxic substances/infections and alcohol.
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Affiliation(s)
- Ina Bergheim
- Department of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
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14
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Pezacki JP, Singaravelu R, Lyn RK. Host-virus interactions during hepatitis C virus infection: a complex and dynamic molecular biosystem. MOLECULAR BIOSYSTEMS 2010; 6:1131-42. [PMID: 20549003 DOI: 10.1039/b924668c] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The hepatitis C virus (HCV) is a global health issue with no vaccine available and limited clinical treatment options. Like other obligate parasites, HCV requires host cellular components of an infected individual to propagate. These host-virus interactions during HCV infection are complex and dynamic and involve the hijacking of host cell environments, enzymes and pathways. Understanding this unique molecular biosystem has the potential to yield new and exciting strategies for therapeutic intervention. Advances in genomics and proteomics have opened up new possibilities for the rapid measurement of global changes at the transcriptional and translational levels during infection. However, these techniques only yield snapshots of host-virus interactions during HCV infection. Other new methods that involve the imaging of biomolecular interactions during HCV infection are required to identify key interactions that may be transient and dynamic. Herein we highlight systems biology based strategies that have helped to identify key host-virus interactions during HCV replication and infection. Novel biophysical tools are also highlighted for identification and visualization of activities and interactions between HCV and its host hepatocyte. As some of these methods mature, we expect them to pave the way forward for further exploration of this complex biosystem and elucidation of mechanisms for HCV pathogenesis and carcinogenesis.
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Affiliation(s)
- John Paul Pezacki
- Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario, Canada.
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15
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Mas VR, Fassnacht R, Archer KJ, Maluf D. Molecular mechanisms involved in the interaction effects of alcohol and hepatitis C virus in liver cirrhosis. Mol Med 2010; 16:287-97. [PMID: 20386865 DOI: 10.2119/molmed.2009.00165] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/25/2010] [Indexed: 12/19/2022] Open
Abstract
The mechanisms by which alcohol consumption accelerates liver disease in patients with chronic hepatitis C virus (HCV) are not well understood. To identify the characteristics of molecular pathways affected by alcohol in HCV patients, we fit probe-set level linear models that included the additive effects as well as the interaction between alcohol and HCV. The study included liver tissue samples from 78 patients, 23 (29.5%) with HCV-cirrhosis, 13 (16.7%) with alcohol-cirrhosis, 23 (29.5%) with HCV/alcohol cirrhosis and 19 (24.4%) with no liver disease (no HCV/no alcohol group). We performed gene-expression profiling by using microarrays. Probe-set expression summaries were calculated by using the robust multiarray average. Probe-set level linear models were fit where probe-set expression was modeled by HCV status, alcohol status, and the interaction between HCV and alcohol. We found that 2172 probe sets (1895 genes) were differentially expressed between HCV cirrhosis versus alcoholic cirrhosis groups. Genes involved in the virus response and the immune response were the more important upregulated genes in HCV cirrhosis. Genes involved in apoptosis regulation were also overexpressed in HCV cirrhosis. Genes of the cytochrome P450 superfamily of enzymes were upregulated in alcoholic cirrhosis, and 1230 probe sets (1051 genes) had a significant interaction estimate. Cell death and cellular growth and proliferation were affected by the interaction between HCV and alcohol. Immune response and response to the virus genes were downregulated in HCV-alcohol interaction (interaction term alcohol*HCV). Alcohol*HCV in the cirrhotic tissues resulted in a strong negative regulation of the apoptosis pattern with concomitant positive regulation of cellular division and proliferation.
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Affiliation(s)
- Valeria R Mas
- Hume-Lee Transplant Center, Division of Transplant, Department of Surgery, Virginia Commonwealth University Health System, Richmond, Virginia 23298-0057, USA.
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16
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Mas VR, Fisher RA, Archer KJ, Maluf DG. Proteomics and liver fibrosis: identifying markers of fibrogenesis. Expert Rev Proteomics 2009; 6:421-31. [PMID: 19681677 DOI: 10.1586/epr.09.59] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Chronic hepatic disease damages the liver and the resulting wound-healing process might lead to liver fibrosis and subsequent cirrhosis development. Fibrosis is the excessive deposition of extracellular matrix (ECM) in the tissue as consequence of chronic liver damage. The fibrotic response triggers almost all of the complications of end-stage liver disease, including portal hypertension, ascites, encephalopathy, synthetic dysfunction and impaired metabolic capacity. Thus, efforts to understand and attenuate fibrosis have direct clinical implications. Reliable, accurate, disease-specific, noninvasive biomarkers of fibrosis and fibrogenesis in order to prevent or minimize the impact of the chronic liver disease progression are a critical need. This review aims to provide an overview of the possibilities that proteome technology can offer to the knowledge, diagnosis and prognosis of liver fibrosis.
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Affiliation(s)
- Valeria R Mas
- Transplant Molecular Laboratory, Transplant Division, Department of Surgery, Molecular Medicine Research Building, Virginia Commonwealth University, 1220 E. Broad Street, Richmond, VA 23298, USA.
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The NS1 protein of the 1918 pandemic influenza virus blocks host interferon and lipid metabolism pathways. J Virol 2009; 83:10557-70. [PMID: 19706713 DOI: 10.1128/jvi.00330-09] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The "Spanish influenza" of 1918 claimed an unprecedented number of lives, yet the determinants of virulence for this virus are still not fully understood. Here, we used functional genomics and an in vitro human lung epithelial cell infection model to define the global host transcriptional response to the eight-gene 1918 virus. To better understand the role of the 1918 virus NS1 gene, we also evaluated the host response to a reassortant 1918 virus containing the NS1 gene from A/Texas/36/91 (a seasonal isolate of human influenza virus), as well as the host response to a reassortant of A/Texas/36/91 containing the 1918 NS1 gene. Genomic analyses revealed that the 1918 virus blocked the transcription of multiple interferon-stimulated genes and also downregulated a network of genes associated with lipid metabolism. In contrast, the expression of genes encoding chemokines and cytokines, which serve to attract infiltrating immune cells, was upregulated. Viruses containing the NS1 gene from A/Texas/36/91 induced a significant increase in type I interferon signaling but did not repress lipid metabolism. The 1918 NS1 gene may therefore have contributed to the virulence of the 1918 pandemic virus by disrupting the innate immune response, inducing hypercytokinemia, and by blocking the transcription of certain lipid-based proinflammatory mediators that function as part of the host antiviral response.
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Abstract
This review will focus on the prevalence of hepatitis c virus (HCV) infection in alcoholics with and without liver disease. Evidence will be presented to demonstrate that ethanol and chronic HCV infection synergistically accelerate liver injury. Some of the major postulated mechanisms responsible for disease progression include high rates of apoptosis, lipid peroxidation, and generation of free radicals and reactive oxygen species with reduced antioxidant capacity of the liver. Acquisition and persistence of HCV infection may be due to the adverse effects of ethanol on humoral and cellular immune responses to HCV. Dendritic cells (DC) appear to be one of the major targets for ethanol's action and DC dysfunction impairs the ability of the host to generate viral specific cluster of differentiation 4 (CD4+) and cluster of differentiation 8 (CD8+) immune responses. There is a relationship between increased alcohol intake and decreased response to interferon (IFN) therapy, which may be reversed by abstinence. Clinical studies are needed to optimize treatment responses in alcoholic patients with chronic HCV infection.
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Affiliation(s)
- Larry Siu
- Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Julie Foont
- Warren Alpert Medical School of Brown University, Providence, Rhode Island
| | - Jack R. Wands
- Warren Alpert Medical School of Brown University, Providence, Rhode Island
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Mölleken C, Sitek B, Henkel C, Poschmann G, Sipos B, Wiese S, Warscheid B, Broelsch C, Reiser M, Friedman SL, Tornøe I, Schlosser A, Klöppel G, Schmiegel W, Meyer HE, Holmskov U, Stühler K. Detection of novel biomarkers of liver cirrhosis by proteomic analysis. Hepatology 2009; 49:1257-66. [PMID: 19177598 PMCID: PMC2895500 DOI: 10.1002/hep.22764] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
UNLABELLED Hepatic cirrhosis is a life-threatening disease arising from different chronic liver disorders. One major cause for hepatic cirrhosis is chronic hepatitis C. Chronic hepatitis C is characterized by a highly variable clinical course, with at least 20% developing liver cirrhosis within 40 years. Only liver biopsy allows a reliable evaluation of the course of hepatitis C by grading inflammation and staging fibrosis, and thus serum biomarkers for hepatic fibrosis with high sensitivity and specificity are needed. To identify new candidate biomarkers for hepatic fibrosis, we performed a proteomic approach of microdissected cirrhotic septa and liver parenchyma cells. In cirrhotic septa, we detected an increasing expression of cell structure associated proteins, including actin, prolyl 4-hydroxylase, tropomyosin, calponin, transgelin, and human microfibril-associated protein 4 (MFAP-4). Tropomyosin, calponin, and transgelin reflect a contribution of activated stellate cells/myofibroblasts to chronic liver injury. The expression of tropomyosin, transgelin, and MFAP-4, an extracellular matrix associated protein, were further evaluated by immunohistochemistry. Tropomyosin and MFAP-4 demonstrated high serum levels in patients with hepatic cirrhosis of different causes. CONCLUSION A quantitative analysis of MFAP-4 serum levels in a large number of patients showed MFAP-4 as novel candidate biomarker with high diagnostic accuracy for prediction of nondiseased liver versus cirrhosis [area under receiver operating characteristic curve (AUC) = 0.97, P < 0.0001] as well as stage 0 versus stage 4 fibrosis (AUC = 0.84, P < 0.0001), and stages 0 to 3 versus stage 4 fibrosis (AUC = 0.76, P < 0.0001).
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Affiliation(s)
- Christian Mölleken
- Department of Internal Medicine, Bergmannsheil, Ruhr-Universität Bochum, Germany
| | - Barbara Sitek
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Germany
| | - Corinna Henkel
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Germany
| | | | - Bence Sipos
- Department of Pathology, Christian Albrechts University, Kiel, Germany
| | - Sebastian Wiese
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Germany
| | | | - Christoph Broelsch
- Department of General Surgery and Transplantation, University Hospital, Essen, Germany
| | - Markus Reiser
- Department of Internal Medicine, Bergmannsheil, Ruhr-Universität Bochum, Germany
| | - Scott L. Friedman
- Division of Liver Diseases, Mount Sinai School of Medicine, New York, New York
| | - Ida Tornøe
- Department of Medical Biology, University of Southern Denmark, Odense, Denmark
| | - Anders Schlosser
- Department of Medical Biology, University of Southern Denmark, Odense, Denmark
| | - Günter Klöppel
- Department of Pathology, Christian Albrechts University, Kiel, Germany
| | - Wolff Schmiegel
- Department of Internal Medicine, Bergmannsheil, Ruhr-Universität Bochum, Germany, Department of Internal Medicine, Knappschaftskrankenhaus, Ruhr-Universität Bochum, Germany
| | - Helmut E. Meyer
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Germany
| | - Uffe Holmskov
- Department of Medical Biology, University of Southern Denmark, Odense, Denmark
| | - Kai Stühler
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Germany
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Walters KA, Katze MG. Using high-throughput genomics to study hepatitis C: what determines the outcome of infection? Antiviral Res 2009; 81:198-208. [PMID: 19135090 DOI: 10.1016/j.antiviral.2008.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 12/04/2008] [Accepted: 12/09/2008] [Indexed: 12/20/2022]
Abstract
High-throughput genomic methods are now being used to study a wide variety of viral diseases, in an effort to understand how host responses to infection can lead either to efficient elimination of the pathogen or the development of severe disease. This article reviews how gene expression studies are addressing important clinical issues related to hepatitis C virus infection, in which some 15-25% of infected individuals are able to clear the virus without treatment, while the remainder progress to chronic liver disease that can lead to cirrhosis and death. Similar methods are also being used in an effort to identify the mechanisms underlying the failure of some hepatitis C patients to respond to interferon-alpha/ribavirin therapy. By providing a detailed picture of virus-host interactions, high-throughput genomics could potentially lead to the identification of novel cellular targets for the treatment of hepatitis C.
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Affiliation(s)
- Kathie-Anne Walters
- Department of Microbiology, University of Washington, 960 Repubublican St., Seattle, WA 98109, USA.
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Abstract
By providing a global and integrated view of the host response to infection, functional genomic and systems-biology approaches are contributing to our understanding of RNA virus–host interactions. One area in which these approaches are being put to particularly good use is in shedding new light on the components of innate antiviral defence mechanisms and the viral strategies used to regulate or overcome them. Genomic analyses have helped to reveal virus-specific differences in the way that viral recognition through pathogen-recognition receptors (PRRs) initiates intracellular signalling cascades. Whereas influenza virus appears to signal primarily through retinoic-acid-inducible gene I (RIG-I), West Nile virus signals through both RIG-I and melanoma differentiation-associated gene 5 (MDA5). Both viruses induce the expression of interferon (IFN)-regulatory factor 3 (IRF3) target genes and IFN-stimulated genes (ISGs). Genomic analyses have provided a comprehensive view of the transcriptional programmes that are induced by Toll-like receptor (TLR) activation. One transcriptional profile is universally activated by all TLRs and a second profile is specific to TLR3 and TLR4. Nuclear factor-κB (NF-κB) is the key regulator of the universal response, which occurs early after TLR stimulation, and the IFN-stimulated response element (ISRE) is the key component of the TLR3/TLR4 response, which is induced after the NF-κB response. Some highly virulent viruses, such as Ebola virus and rabies virus, are successful at inhibiting ISG expression, resulting in the marked suppression of genes in key innate antiviral pathways, including those mediated by IRF3. There seems to be a correlation between the antagonism of the IFN response and virulence. Genomic analyses of the host response to the reconstructed 1918 pandemic influenza virus have revealed similarities and differences to contemporary influenza virus infection. Contemporary and 1918 influenza viruses each trigger an innate immune response that includes the expression of NF-κB and IRF3 target genes, and both viruses trigger a robust cytokine response that attracts immune-cell infiltration to infected tissues. Unlike contemporary virus strains, in which the early response to infection is resolved, the innate immune response triggered by the 1918 influenza virus is characterized by a strong and sustained induction that is associated with massive tissue damage and death. Global gene-expression profiling has revealed that many effective, attenuated live-virus vaccines transiently induce a stronger type I IFN response than the cognate pathogen, and therefore implicates modulation of this response as an important strategy in rational vaccine design.
By providing a global view of the host response to infection, functional genomic approaches are proving useful in deciphering complex virus–host interactions. Here, the authors reveal how such approaches are being used to better understand viral triggering and regulation of host innate immune responses. Although often encoding fewer than a dozen genes, RNA viruses can overcome host antiviral responses and wreak havoc on the cells they infect. Some manage to evade host antiviral defences, whereas others elicit an aberrant or disproportional immune response. Both scenarios can result in the disruption of intracellular signalling pathways and significant pathology in the host. Systems-biology approaches are increasingly being used to study the processes of viral triggering and regulation of host immune responses. By providing a global and integrated view of cellular events, these approaches are beginning to unravel some of the complexities of virus–host interactions and provide new insights into how RNA viruses cause disease.
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Abstract
Eradication of hepatitis C virus (HCV) infection requires a complex and coordinated interplay between innate and adaptive immune responses that, when it fails, leads to chronic infection. In this review, the innate immune mechanisms by which HCV is sensed and by which HCV undermines host defense are discussed. The critical role of dendritic cells in antigen presentation and T-cell activation in addition to type I interferon production and interference of HCV with innate immune cell functions are reviewed. Finally, current and emerging therapeutic approaches targeting innate immune pathways are evaluated.
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Abstract
Infection with influenza typically results in mild‐to‐moderate illness in healthy individuals; however, it is responsible for 30,000–40,000 deaths each year in the United States. In extreme cases, such as the influenza pandemic of 1918, tens of millions of people have died from the infection. To prepare for future influenza outbreaks, it is necessary to understand how the virus interacts with the host and to determine what makes certain strains of influenza highly pathogenic. Functional genomics provides a unique approach to this effort by allowing researchers to examine the effect of influenza infection on global host mRNA levels. Researchers are making increasing use of this approach to study virus–host interactions using a variety of model systems. For example, data obtained using microarray technology, in combination with mouse and macaque infection models, is providing exciting new insights into the pathogenicity of the 1918 virus. These studies suggest that the lethality associated with this virus is in part due to an aberrant and unchecked immune response. Progress is also being made toward using functional genomics in the diagnosis and prognosis of acute lung infections and in the development of more effective influenza vaccines and antivirals.
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Affiliation(s)
- Jamie L Fornek
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA
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Katze MG, Korth MJ. Lost in the world of functional genomics, systems biology, and translational research: is there life after the Milstein award? Cytokine Growth Factor Rev 2007; 18:441-50. [PMID: 17681845 PMCID: PMC1994668 DOI: 10.1016/j.cytogfr.2007.06.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have always wanted to save the world from the scourges of virus infection by developing better drugs and vaccines. But fully understanding the intricacies of virus-host interactions, the first step in achieving this goal, requires the ability to view the process on a grand scale. The advent of high-throughput technologies, such as DNA microarrays and mass spectrometry, provided the first opportunities to obtain such a view. Here, we describe our efforts to use these tools to focus on the changes in cellular gene expression and protein abundance that occur in response to virus infection. By examining these changes in a comprehensive manner, we have been able to discover exciting new insights into innate immunity, interferon and cytokine signaling, and the strategies used by viruses to overcome these cellular defenses. Functional genomics may yet save the world from killer viruses.
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Affiliation(s)
- Michael G Katze
- Department of Microbiology and Washington National Primate Research Center, University of Washington, Seattle, WA 98195-8070, USA.
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Abstract
PURPOSE OF REVIEW This review aims to acquaint the reader with advances in 2006 in the epidemiology, genetics, detection, pathogenesis and treatment of alcoholic liver disease. RECENT FINDINGS Important discoveries have been made in pathogenesis and mechanism of disease, with great emphasis on the many pathways leading to oxidative stress, and the novel mechanism of endoplasmic reticulum stress that is proving to be important in the pathogenesis of many liver diseases. The reliability of ethyl glucuronide and other biomarkers for the detection of alcohol abuse is being better established. There have been no treatment advances for alcoholic liver disease but, on balance, steroids are still favored for carefully selected patients with alcoholic hepatitis. Many compounds tested in rodents may now be available for consideration for clinical trials. Criteria for patient selection and refusal for liver transplantation are being established but the 6 months abstinence rule still holds. SUMMARY Insights are being made into the pathogenesis of alcoholic liver disease but safe and effective therapies for both alcoholic hepatitis and alcoholic cirrhosis have yet to be discovered.
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Affiliation(s)
- Adrian Reuben
- Liver Service, Division of Gastroenterology and Hepatology, And Liver Transplant Program, Medical University of South Carolina, Charleston, South Carolina, USA.
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