Dendritic Cells In Hepatitis C Infection: Can They (Help) Win The Battle,
2012
University of Massachusetts Medical School
Dendritic Cells In Hepatitis C Infection: Can They (Help) Win The Battle, Angela Dolganiuc, Gyongyi Szabo
Gyongyi Szabo
Infection with hepatitis C virus (HCV) is a public health problem; it establishes a chronic course in ~85% of infected patients and increases their risk for developing liver cirrhosis, hepatocellular carcinoma, and significant extrahepatic manifestations. The mechanisms of HCV persistence remain elusive and are largely related to inefficient clearance of the virus by the host immune system. Dendritic cells (DCs) are the most efficient inducers of immune responses; they are capable of triggering productive immunity and maintaining the state of tolerance to self- and non-self antigens. During the past decade, multiple research groups have focused on DCs, in hopes of …
Inflammasomes In Liver Diseases,
2012
University of Massachusetts Medical School
Inflammasomes In Liver Diseases, Gyongyi Szabo, Timea Csak
Gyongyi Szabo
Inflammation is a common element in the pathogenesis of most chronic liver diseases that lead to fibrosis and cirrhosis. Inflammation is characterized by activation of innate immune cells and production of pro-inflammatory cytokines IL-1alpha, IL-1beta, and TNFalpha. Inflammasomes are intracellular multiprotein complexes expressed in both parenchymal and non-parenchymal cells of the liver that in response to cellular danger signals activate caspase-1, and release IL-1beta and IL-18. The importance of inflammasome activation in various forms of liver diseases in relation to liver damage, steatosis, inflammation and fibrosis is discussed in this review. Elsevier B.V. All rights reserved.
Hypoxia And Hypoxia Inducible Factors: Diverse Roles In Liver Diseases,
2012
University of Massachusetts Medical School
Hypoxia And Hypoxia Inducible Factors: Diverse Roles In Liver Diseases, Bharath Nath, Gyongyi Szabo
Gyongyi Szabo
Hypoxia has been shown to have a role in the pathogenesis of several forms of liver disease. The hypoxia inducible factors (HIFs) are a family of evolutionarily conserved transcriptional regulators that affect a homeostatic response to low oxygen tension and have been identified as key mediators of angiogenesis, inflammation, and metabolism. In this review we summarize the evidence for a role of HIFs across a range of hepatic pathophysiology. We describe regulation of the HIFs and review investigations that demonstrate a role for HIFs in the development of liver fibrosis, activation of innate immune pathways, hepatocellular carcinoma, as well as …
Microrna Signature In Alcoholic Liver Disease,
2012
University of Massachusetts Medical School
Microrna Signature In Alcoholic Liver Disease, Shashi Bala, Gyongyi Szabo
Gyongyi Szabo
Alcoholic liver disease (ALD) is a major global health problem. Chronic alcohol use results in inflammation and fatty liver, and in some cases, it leads to fibrosis and cirrhosis or hepatocellular carcinoma. Increased proinflammatory cytokines, particularly TNF alpha, play a central role in the pathogenesis of ALD. TNF alpha is tightly regulated at transcriptional and posttranscriptional levels. Recently, microRNAs (miRNAs) have been shown to modulate gene functions. The role of miRNAs in ALD is getting attention, and recent studies suggest that alcohol modulates miRNAs. Recently, we showed that alcohol induces miR-155 expression both in vitro (RAW 264.7 macrophage) and in …
Mitochondrial Antiviral Signaling Protein Defect Links Impaired Antiviral Response And Liver Injury In Steatohepatitis In Mice,
2012
University of Massachusetts Medical School
Mitochondrial Antiviral Signaling Protein Defect Links Impaired Antiviral Response And Liver Injury In Steatohepatitis In Mice, Timea Csak, Angela Dolganiuc, Karen Kodys, Bharath Nath, Jan Petrasek, Shashi Bala, Dora Lippai, Gyongyi Szabo
Gyongyi Szabo
Mitochondrial dysfunction is a pathogenic feature of nonalcoholic steatohepatitis (NASH). NASH complicates hepatotropic viral disease. The mitochondrial antiviral signaling protein (MAVS) is the adapter of helicase receptors involved in sensing double-stranded RNA (dsRNA). We hypothesized that impaired MAVS function may contribute to insufficient antiviral response and liver damage in steatohepatitis. We identified reduced MAVS protein levels and increased MAVS association with the proteasome subunit alpha type 7 (PSMA7) in livers from mice given a methionine-choline-deficient (MCD) diet. Decreased association of MAVS with mitochondria and increased cytosolic cytochrome c indicated mitochondrial damage in steatohepatitis. In vivo administration of the synthetic dsRNA …
The Presence Of P47phox In Liver Parenchymal Cells Is A Key Mediator In The Pathogenesis Of Alcoholic Liver Steatosis,
2012
University of Massachusetts Medical School
The Presence Of P47phox In Liver Parenchymal Cells Is A Key Mediator In The Pathogenesis Of Alcoholic Liver Steatosis, Ivan Levin, Jan Petrasek, Gyongyi Szabo
Gyongyi Szabo
BACKGROUND: Reactive oxygen species contribute to steatosis and inflammation in alcoholic liver disease (ALD). Here, we evaluated the selective contribution of p47phox, a critical subunit of nicotinamide adenine dinucleotide phosphate oxidase (NADPH) oxidase complex, in liver parenchymal cells and in bone marrow (BM)-derived cells. METHODS: Female C57Bl/6 wild type [WT], total body p47phox-deficient knockout [KO] or p47phox chimera mice generated by BM transplantation of p47phox-KO-BM into irradiated WT mice (WT/p47phox-KO-BM mice) received 5% Lieber-DeCarli alcohol or control (pair feeding) diet for 4 weeks. RESULTS: Alcohol-induced liver steatosis as measured by Oil Red O staining and serum triglyceride up-regulation were prevented …
Ethanol Facilitates Hcv Replication Via Upregulation Of Gw182 And Hsp90 In Human Hepatoma Cells,
2012
University of Massachusetts Medical School
Ethanol Facilitates Hcv Replication Via Upregulation Of Gw182 And Hsp90 In Human Hepatoma Cells, Terence Bukong, Wei Hou, Karen Kodys, Gyongyi Szabo
Gyongyi Szabo
Alcohol use and hepatitis C virus (HCV) infection synergize to cause liver damage and microRNA-122 (miR-122) appears to play a key role in this process. Argonaute 2 (Ago2), a key component of the RNA-induced silencing complex, has been shown to be important in modulating miR-122 function during HCV infection. However, GW182, a critical component of processing bodies (GW-bodies) that is recruited by Ago2 to target mRNA has not been assessed in HCV infection. To characterize the role of GW182 in the pathogenesis of HCV infection, we determined its transcription and protein expression in an HCV J6/JFH1 culture system. Here we …
An Essential Role For Monocyte Chemoattractant Protein-1 In Alcoholic Liver Injury: Regulation Of Proinflammatory Cytokines And Hepatic Steatosis In Mice,
2012
University of Massachusetts Medical School
An Essential Role For Monocyte Chemoattractant Protein-1 In Alcoholic Liver Injury: Regulation Of Proinflammatory Cytokines And Hepatic Steatosis In Mice, Pranoti Mandrekar, Aditya Ambade, Arlene Lim, Gyongyi Szabo, Donna Catalano
Gyongyi Szabo
The importance of chemokines in alcoholic liver injury has been implicated. The role of the chemokine, monocyte chemoattractant protein-1 (MCP-1), elevated in patients with alcoholic liver disease is not yet understood. Here, we evaluated the pathophysiological significance of MCP-1 and its receptor, chemokine (C-C motif) receptor 2 (CCR2), in alcoholic liver injury. The Leiber-DeCarli diet containing alcohol or isocaloric control diets were fed to wild-type (WT) and MCP-1-deficient knockout (KO) mice for 6 weeks. In vivo and in vitro assays were performed to study the role of MCP-1 in alcoholic liver injury. MCP-1 was increased in Kupffer cells (KCs) as …
Microrna Silencing And The Development Of Novel Therapies For Liver Disease,
2012
University of Massachusetts Medical School
Microrna Silencing And The Development Of Novel Therapies For Liver Disease, Gyongyi Szabo, Peter Sarnow, Shashi Bala
Gyongyi Szabo
In recent years microRNAs have emerged as crucial small non-coding RNA molecules with diverse roles in various diseases including diseases of the liver. In this review, we highlight the latest advances in the field of microRNA biology and their potential as emerging therapeutic targets in liver disease. Elsevier B.V. All rights reserved.
Reduction In Hepatic Inflammation Is Associated With Less Fibrosis Progression And Fewer Clinical Outcomes In Advanced Hepatitis C,
2012
University of Washington
Reduction In Hepatic Inflammation Is Associated With Less Fibrosis Progression And Fewer Clinical Outcomes In Advanced Hepatitis C, Chihiro Morishima, Mitchell Shiffman, Jules Dienstag, Karen Lindsay, Gyongyi Szabo, Gregory Everson, Anna Lok, Adrian Di Bisceglie, Marc Ghany, Deepa Naishadham, Timothy Morgan, Elizabeth Wright
Gyongyi Szabo
OBJECTIVES:During the Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial, 3.5 years of maintenance peginterferon-alfa-2a therapy did not affect liver fibrosis progression or clinical outcomes among 1,050 previous interferon nonresponders with advanced fibrosis or cirrhosis. We investigated whether reduced hepatic inflammation was associated with clinical benefit in 834 patients with a baseline and follow-up biopsy 1.5 years after randomization to peginterferon or observation. METHODS:Relationships between change in hepatic inflammation (Ishak hepatic activity index, (HAI)) and serum alanine aminotransferase level, fibrosis progression and clinical outcomes after randomization, and hepatitis C virus (HCV) RNA decline before and after randomization were evaluated. Histological …
Human Monoclonal Antibody Hcv1 Effectively Prevents And Treats Hcv Infection In Chimpanzees,
2012
University of Massachusetts Medical School
Human Monoclonal Antibody Hcv1 Effectively Prevents And Treats Hcv Infection In Chimpanzees, Trevor J. Morin, Teresa J. Broering, Brett A. Leav, Barbara M. Blair, Kirk J. Rowley, Elisabeth N. Boucher, Yang Wang, Peter S. Cheslock, Michael Knauber, David B. Olsen, Steve W. Ludmerer, Gyongyi Szabo, Robert W. Finberg, Robert H. Purcell, Robert E. Lanford, Donna M. Ambrosino, Deborah C. Molrine, Gregory J. Babcock
Gyongyi Szabo
Hepatitis C virus (HCV) infection is a leading cause of liver transplantation and there is an urgent need to develop therapies to reduce rates of HCV infection of transplanted livers. Approved therapeutics for HCV are poorly tolerated and are of limited efficacy in this patient population. Human monoclonal antibody HCV1 recognizes a highly-conserved linear epitope of the HCV E2 envelope glycoprotein (amino acids 412-423) and neutralizes a broad range of HCV genotypes. In a chimpanzee model, a single dose of 250 mg/kg HCV1 delivered 30 minutes prior to infusion with genotype 1a H77 HCV provided complete protection from HCV infection, …
Cd81/Cd9 Tetraspanins Aid Plasmacytoid Dendritic Cells In Recognition Of Hcv-Infected Cells And Induction Of Ifnalpha,
2012
University of Massachusetts Medical School
Cd81/Cd9 Tetraspanins Aid Plasmacytoid Dendritic Cells In Recognition Of Hcv-Infected Cells And Induction Of Ifnalpha, Shuye Zhang, Karen Kodys, Gregory Babcock, Gyongyi Szabo
Gyongyi Szabo
Recognition of hepatitis C virus (HCV)-infected hepatocyes and interferon (IFN) induction are critical in antiviral immune response. We hypothesized that cell-cell contact between plasmacytoid dendritic cells (pDCs) and HCV-infected cells was required for IFNalpha induction via involvement of cell surface molecules. Co-culture of human peripheral blood mononuclear cells (PBMCs) with genotype 1a full length HCV genomic replicon cells (FL) or genotype 2a JFH-1 virus infected hepatoma cells (JFH-1), not with uninfected hepatoma cells (Huh7.5), induced IFNalpha production. Depletion of pDCs from PBMCs attenuated IFNalpha release and purified pDCs produced high levels of IFNalpha after co-culture with FL replicons or JFH-1 …
Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice,
2012
University of Massachusetts Medical School
Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo
Gyongyi Szabo
Chronic alcohol causes hepatic steatosis and liver hypoxia. Hypoxia-regulated hypoxia-inducible factor 1-alpha, (HIF-1alpha) may regulate liporegulatory genes, but the relationship of HIF-1 to steatosis remains unknown. We investigated HIF-1alpha in alcohol-induced hepatic lipid accumulation. Alcohol administration resulted in steatosis, increased liver triglyceride levels, and increased serum alanine aminotransferase (ALT) levels, suggesting liver injury in wild-type (WT) mice. There was increased hepatic HIF-1alpha messenger RNA (mRNA), protein, and DNA-binding activity in alcohol-fed mice compared with controls. Mice engineered with hepatocyte-specific HIF-1 activation (HIF1dPA) had increased HIF-1alpha mRNA, protein, and DNA-binding activity, and alcohol feeding in HIF1dPA mice increased hepatomegaly and hepatic …
Il-1 Receptor Antagonist Ameliorates Inflammasome-Dependent Alcoholic Steatohepatitis In Mice,
2012
University of Massachusetts Medical School
Il-1 Receptor Antagonist Ameliorates Inflammasome-Dependent Alcoholic Steatohepatitis In Mice, Jan Petrasek, Shashi Bala, Timea Csak, Dora Lippai, Karen Kodys, Victoria Menashy, Matthew Barrieau, So-Yun Min, Evelyn A. Kurt-Jones, Gyongyi Szabo
Gyongyi Szabo
Alcoholic liver disease (ALD) is characterized by steatosis and upregulation of proinflammatory cytokines, including IL-1beta. IL-1beta, type I IL-1 receptor (IL-1R1), and IL-1 receptor antagonist (IL-1Ra) are all important regulators of the IL-1 signaling complex, which plays a role in inflammation. Furthermore, IL-1beta maturation is dependent on caspase-1 (Casp-1). Using IL-1Ra-treated mice as well as 3 mouse models deficient in regulators of IL-1beta activation (Casp-1 and ASC) or signaling (IL-1R1), we found that IL-1beta signaling is required for the development of alcohol-induced liver steatosis, inflammation, and injury. Increased IL-1beta was due to upregulation of Casp-1 activity and inflammasome activation. The …
Induction Of Bcl-3 By Acute Binge Alcohol Results In Toll-Like Receptor 4/Lps Tolerance,
2012
University of Massachusetts Medical School
Induction Of Bcl-3 By Acute Binge Alcohol Results In Toll-Like Receptor 4/Lps Tolerance, Shashi Bala, Alexander Tang, Donna Catalano, Jan Petrasek, Odette Taha, Karen Kodys, Gyongyi Szabo
Gyongyi Szabo
Acute alcohol binge results in immunosuppression and impaired production of proinflammatory cytokines, including TNF-alpha. TNF-alpha production is induced by LPS, a TLR4 ligand, and is tightly regulated at various levels of the signaling cascade, including the NF-kappaB transcription factor. Here, we hypothesized that acute alcohol induces TLR4/LPS tolerance via Bcl-3, a nuclear protein and member of the NF-kappaB family. We found that acute alcohol pretreatment resulted in the same attenuating effect as LPS pretreatment on TLR4-induced TNF-alpha production in human monocytes and murine RAW 264.7 macrophages. Acute alcohol-induced Bcl-3 expression and IP studies revealed increased association of Bcl-3 with NF-kappaB …
Novel Developmental Biology-Based Protocol Of Embryonic Stem Cell Differentiation To Morphologically Sound And Functional Yet Immature Hepatocytes,
2012
University of Massachusetts Medical School
Novel Developmental Biology-Based Protocol Of Embryonic Stem Cell Differentiation To Morphologically Sound And Functional Yet Immature Hepatocytes, Terence Bukong, Tracie Lo, Gyongyi Szabo, Angela Dolganiuc
Gyongyi Szabo
BACKGROUND/AIMS: Liver diseases are common in the United States and often require liver transplantation; however, donated organs are limited and thus alternative sources for liver cells are in high demand. Embryonic stem cells (ESC) can provide a continuous and readily available source of liver cells. ESC differentiation to liver cells is yet to be fully understood and comprehensive differentiation protocols are yet to be defined. Here, we aimed to achieve human (h)ESC differentiation into mature hepatocytes using defined recombinant differentiation factors and metabolites. METHODS: Embryonic stem cell H1 line was sub-cultured on feeder layer. We induced hESCs into endodermal differentiation …
Lipopolysaccharide Induces And Activates The Nalp3 Inflammasome In The Liver,
2012
University of Massachusetts Medical School
Lipopolysaccharide Induces And Activates The Nalp3 Inflammasome In The Liver, Michal Ganz, Timea Csak, Bharath D. Nath, Gyongyi Szabo
Gyongyi Szabo
AIM: To examine the activation of the Nalp3 inflammasome and its downstream targets following lipopolysaccharide (LPS)-induced stimulation in the liver. METHODS: Six-to-eight-week-old C57BL/6 chow fed mice were injected intraperitoneally with 0.5 mug/g bodyweight LPS and sacrificed 2, 4, 6, 18 or 24 h later. LPS-induced liver damage was confirmed by a biochemical assay to detect alanine aminotransferase (ALT) levels. To determine if LPS stimulation in the liver led to activation of the inflammasome, real-time quantitative polymerase chain reaction was used to evaluate the mRNA expression of components of the Nalp3 inflammasome. Enzyme-linked immunosorbent assays were used to determine the protein …
Circulating Micrornas In Exosomes Indicate Hepatocyte Injury And Inflammation In Alcoholic, Drug-Induced, And Inflammatory Liver Diseases,
2012
University of Massachusetts Medical School
Circulating Micrornas In Exosomes Indicate Hepatocyte Injury And Inflammation In Alcoholic, Drug-Induced, And Inflammatory Liver Diseases, Shashi Bala, Jan Petrasek, Shiv Mundkur, Donna Catalano, Ivan Levin, Jeanine Ward, Hawau Alao, Karen Kodys, Gyongyi Szabo
Gyongyi Szabo
MicroRNAs are fine tuners of diverse biological responses and are expressed in various cell types of the liver. Here we hypothesized that circulating microRNAs (miRNAs) may serve as biomarkers of liver damage and inflammation. We studied miRNA-122, which is abundant in hepatocytes, and miR-155, -146a, and -125b, which regulate inflammation in immune cells in mouse models of alcoholic liver disease (ALD), drug (acetaminophen, APAP)-induced liver injury (DILI), and Toll-like receptor (TLR) 9+4 ligand-induced inflammatory cell-mediated liver damage. We found that serum/plasma miR-122 correlated with alanine aminotransferase (ALT) increases in the liver damage caused by alcohol, APAP, and TLR9 (CpG)+4 (LPS) …
Fatty Acid And Endotoxin Activate Inflammasomes In Mouse Hepatocytes That Release Danger Signals To Stimulate Immune Cells,
2012
University of Massachusetts Medical School
Fatty Acid And Endotoxin Activate Inflammasomes In Mouse Hepatocytes That Release Danger Signals To Stimulate Immune Cells, Timea Csak, Michal Ganz, Justin Pespisa, Karen Kodys, Angela Dolganiuc, Gyongyi Szabo
Gyongyi Szabo
The pathogenesis of nonalcoholic steatohepatitis (NASH) and inflammasome activation involves sequential hits. The inflammasome, which cleaves pro-interleukin-1beta (pro-IL-1beta) into secreted IL-1beta, is induced by endogenous and exogenous danger signals. Lipopolysaccharide (LPS), a toll-like receptor 4 ligand, plays a role in NASH and also activates the inflammasome. In this study, we hypothesized that the inflammasome is activated in NASH by multiple hits involving endogenous and exogenous danger signals. Using mouse models of methionine choline-deficient (MCD) diet-induced NASH and high-fat diet-induced NASH, we found up-regulation of the inflammasome [including NACHT, LRR, and PYD domains-containing protein 3 (NALP3; cryopyrin), apoptosis-associated speck-like CARD-domain containing …
Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice,
2012
University of Massachusetts Medical School
Hepatocyte-Specific Hypoxia-Inducible Factor-1alpha Is A Determinant Of Lipid Accumulation And Liver Injury In Alcohol-Induced Steatosis In Mice, Bharath Nath, Ivan Levin, Timea Csak, Jan Petrasek, Christian Mueller, Karen Kodys, Donna Catalano, Pranoti Mandrekar, Gyongyi Szabo
Christian Mueller
Chronic alcohol causes hepatic steatosis and liver hypoxia. Hypoxia-regulated hypoxia-inducible factor 1-alpha, (HIF-1alpha) may regulate liporegulatory genes, but the relationship of HIF-1 to steatosis remains unknown. We investigated HIF-1alpha in alcohol-induced hepatic lipid accumulation. Alcohol administration resulted in steatosis, increased liver triglyceride levels, and increased serum alanine aminotransferase (ALT) levels, suggesting liver injury in wild-type (WT) mice. There was increased hepatic HIF-1alpha messenger RNA (mRNA), protein, and DNA-binding activity in alcohol-fed mice compared with controls. Mice engineered with hepatocyte-specific HIF-1 activation (HIF1dPA) had increased HIF-1alpha mRNA, protein, and DNA-binding activity, and alcohol feeding in HIF1dPA mice increased hepatomegaly and hepatic …
