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Liver Damage (liver + damage)
Kinds of Liver Damage Selected AbstractsAlcohol and Hepatitis C Virus,Interactions in Immune Dysfunctions and Liver DamageALCOHOLISM, Issue 10 2010Gyongyi Szabo Hepatitis C virus infection affects 170 million people worldwide, and the majority of individuals exposed to HCV develop chronic hepatitis leading to progressive liver damage, cirrhosis, and hepatocellular cancer. The natural history of HCV infection is influenced by genetic and environmental factors of which chronic alcohol use is an independent risk factor for cirrhosis in HCV-infected individuals. Both the hepatitis C virus and alcohol damage the liver and result in immune alterations contributing to both decreased viral clearance and liver injury. This review will capture the major components of the interactions between alcohol and HCV infection to provide better understanding for the molecular basis of the dangerous combination of alcohol use and HCV infection. Common targets of HCV and alcohol involve innate immune recognition and dendritic cells, the critical cell type in antigen presentation and antiviral immunity. In addition, both alcohol and HCV affect intracellular processes critical for hepatocyte and immune cell functions including mitochondrial and proteasomal activation. Finally, both chronic alcohol use and hepatitis C virus infection increase the risk of hepatocellular cancer. The common molecular mechanisms underlying the pathological interactions between alcohol and HCV include the modulation of cytokine production, lipopolysaccharide (LPS)-TLR4 signaling, and reactive oxygen species (ROS) production. LPS-induced chronic inflammation is not only a major cause of progressive liver injury and fibrosis, but it can also contribute to modification of the tissue environment and stem cells to promote hepatocellular cancer development. Alteration of these processes by alcohol and HCV produces an environment of impaired antiviral immune response, greater hepatocellular injury, and activation of cell proliferation and dedifferentiation. [source] Nitric Oxide-Mediated Intestinal Injury Is Required for Alcohol-Induced Gut Leakiness and Liver DamageALCOHOLISM, Issue 7 2009Yueming Tang Background:, Alcoholic liver disease (ALD) requires endotoxemia and is commonly associated with intestinal barrier leakiness. Using monolayers of intestinal epithelial cells as an in vitro barrier model, we showed that ethanol-induced intestinal barrier disruption is mediated by inducible nitric oxide synthase (iNOS) upregulation, nitric oxide (NO) overproduction, and oxidation/nitration of cytoskeletal proteins. We hypothesized that iNOS inhibitors [NG-nitro- l -arginine methyl ester (l -NAME), l -N6 -(1-iminoethyl)-lysine (l -NIL)] in vivo will inhibit the above cascade and liver injury in an animal model of alcoholic steatohepatitis (ASH). Methods:, Male Sprague,Dawley rats were gavaged daily with alcohol (6 g/kg/d) or dextrose for 10 weeks ± l -NAME, l -NIL, or vehicle. Systemic and intestinal NO levels were measured by nitrites and nitrates in urine and tissue samples, oxidative damage to the intestinal mucosa by protein carbonyl and nitrotyrosine, intestinal permeability by urinary sugar tests, and liver injury by histological inflammation scores, liver fat, and myeloperoxidase activity. Results:, Alcohol caused tissue oxidation, gut leakiness, endotoxemia, and ASH. l -NIL and l -NAME, but not the d -enantiomers, attenuated all steps in the alcohol-induced cascade including NO overproduction, oxidative tissue damage, gut leakiness, endotoxemia, hepatic inflammation, and liver injury. Conclusions:, The mechanism we reported for alcohol-induced intestinal barrier disruption in vitro , NO overproduction, oxidative tissue damage, leaky gut, endotoxemia, and liver injury , appears to be relevant in vivo in an animal model of alcohol-induced liver injury. That iNOS inhibitors attenuated all steps of this cascade suggests that prevention of this cascade in alcoholics will protect the liver against the injurious effects of chronic alcohol and that iNOS may be a useful target for prevention of ALD. [source] Effects of Embelin on Lipid Peroxidation and Free Radical Scavenging Activity against Liver Damage in RatsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2009Dharmendra Singh Carbon tetrachloride (CCl4) treatment to rats has been more susceptible to peroxidative damage through production of reactive metabolites, namely trichloromethyl-free radicals (CCl?3 and/or CCl3OO?) as measured by thiobarbituric acid reactive species. After the induction of liver damage by CCl4 intoxication to rats, the concentration of lipid peroxidation was significantly (P , 0.001) higher in liver and serum, along with concomitant decrease in the levels of antioxidants and cytochrome P450 enzyme in liver as compared to vehicle controls. The activities of marker enzymes , transaminases (AST, ALT), alkaline phosphatase (ALP), ,-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH) , along with the total bilirubin and total protein levels were altered significantly (P , 0.001) in the serum of CCl4 -treated rats. When these rats received embelin orally (25 mg/kg) from day 1 to day 15, peroxidative damage was minimal in both liver and serum along with effectively inducing the antioxidant potential in CCl4 -treated rats. The biochemical results were compared with the standard drug silymarin , a combination of flavonolignans of Silybum marianum and histology of liver sections. In conclusion, this study suggests that embelin acts as a natural antioxidant against hepatotoxicity induced in rats. [source] Liver damage underlying unexplained transaminase elevation in human immunodeficiency virus-1 mono-infected patients on antiretroviral therapy,HEPATOLOGY, Issue 2 2009Patrick Ingiliz Liver damage associated with chronic unexplained high serum transaminases in human immunodeficiency virus (HIV)-infected patients under combined antiretroviral therapy is unknown. Liver histology was prospectively investigated in patients presenting serum transaminase elevation for more than 6 months, after exclusion of alcohol abuse, hepatitis C virus (HCV) or hepatitis B virus (HBV) infection, autoimmune, and genetic liver diseases. In a subgroup of patients, liver mitochondrial activities were measured by spectrophotometry and mitochondrial DNA (mtDNA) by real-time polymerase chain reaction (PCR). Thirty patients were included with median values of alanine aminotransferase (ALT) levels: 80 U/L, age: 46 years, body mass index: 23 kg/m2, HIV RNA: 200 copies/mL, CD4 count: 365/mm3, duration of HIV infection: 13 years, and duration of treatment exposure: 118, 41, and 53 months for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively. Histological anomalies were found in 22 of 30 patients. Steatosis was present in 18 patients, severe in nine patients, and associated with inflammation in 16 patients with a diagnosis of non-alcoholic steatohepatitis (NASH). Fibrosis was found in 18 patients, severe in six patients and associated with steatosis in 13 patients. Significant liver respiratory complex I defect, contrasting with high complex IV activity and normal mitochondrial DNA content, was observed in the group of patients compared with controls. The presence of NASH was correlated with high fasting glycemia and insulin levels, not with liver mitochondrial function or mitochondrial DNA content. Conclusions: HIV-infected patients on combined antiretroviral therapy with chronic transaminase elevation of unknown origin have a high rate of liver lesions, mostly consistent with NASH related to insulin resistance. (HEPATOLOGY 2008.) [source] Acute liver damage and subsequent hypophosphatemia in malnourished patients: Case reports and review of literatureINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 2 2008Takatoshi Saito MD Abstract Objective: The relationship between liver damage and subsequent hypophosphatemia in malnourished patients will be discussed. Method: The authors report two malnourished females who developed severe liver damage and subsequent hypophosphatemia. Liver damage commenced suddenly after over a week of hospitalization and deteriorated rapidly. Although the precise pathology of the liver damage could not be determined and the specific cause was not identified, steatohepatitis associated with fatty liver might be considered. Results: Hypophosphatemia following liver damage was considered to be the result of hepatocyte regeneration and replacement of phosphorus was an effective treatment. Conclusion: Hypophosphatemia in these cases suggested improvement from liver damage; however, it is commonly known that hypophosphatemia has a central role in refeeding syndrome in malnourished patients. Therefore, it was concluded that attention should be paid to hypophosphatemia after liver damage. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2008 [source] Melatonin ameliorates nonalcoholic fatty liver induced by high-fat diet in ratsJOURNAL OF PINEAL RESEARCH, Issue 1 2006Min Pan Abstract:, Nonalcoholic fatty liver disease (NAFLD) is an increasingly recognized condition that may progress to end-stage liver disease, which ranges from simple steatosis to steatohepatitis, advanced fibrosis, and cirrhosis. Oxidative stress and lipid peroxidation are key pathophysiological mechanisms in NAFLD. We investigate the preventive effects of intraperitoneal administration of melatonin (2.5, 5, 10 mg/kg, daily, respectively) in NAFLD rats induced by high-fat diets for 12 wk. Liver damage was evaluated by serological analysis, serum and hepatic lipid assay as well as hematoxylin,eosin staining in liver sections. Oxidative stress and lipid peroxidation were assessed by measuring malondialdehyde (MDA) levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in liver. The results showed that high-fat diet induced oxidative stress with extensive liver steatosis in rats. Melatonin (5 or 10 mg/kg) was effective in reducing hepatic steatosis and inflammation with lowering serum alanine aminotransferase, aspartate aminotransferase, and levels liver total cholesterol and triglycerides in high-fat diet rats. Moreover, melatonin (2.5, 5, 10 mg/kg) increased SOD and GSH-Px activities and the 10 mg/kg dose of melatonin reduced MDA levels in liver. This study shows that melatonin exerts protective effects against fatty liver in rats induced by high-fat diet possibly through its antioxidant actions. [source] Current Experimental Perspectives on the Clinical Progression of Alcoholic Liver DiseaseALCOHOLISM, Issue 10 2009Katja Breitkopf Chronic alcohol abuse is an important cause of morbidity and mortality throughout the world. Liver damage due to chronic alcohol intoxication initially leads to accumulation of lipids within the liver and with ongoing exposure this condition of steatosis may first progress to an inflammatory stage which leads the way for fibrogenesis and finally cirrhosis of the liver. While the earlier stages of the disease are considered reversible, cirrhotic destruction of the liver architecture beyond certain limits causes irreversible damage of the organ and often represents the basis for cancer development. This review will summarize current knowledge about the molecular mechanisms underlying the different stages of alcoholic liver disease (ALD). Recent observations have led to the identification of new molecular mechanisms and mediators of ALD. For example, plasminogen activator inhibitor 1 was shown to play a central role for steatosis, the anti-inflammatory adipokine, adiponectin profoundly regulates liver macrophage function and excessive hepatic deposition of iron is caused by chronic ethanol intoxication and increases the risk of hepatocellular carcinoma development. [source] T cell costimulation by the hepatitis C virus envelope protein E2 binding to CD81 is mediated by LckEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2003Elisabetta Soldaini Abstract Binding of the hepatitis C virus (HCV) envelope protein E2 to CD81 provides a costimulatory signal for human T cells. This phenomenon may play a role in liver damage and autoimmune manifestations associated with HCV infection. Here we show that cross-linking of CD81 by HCV E2 induced a calcium flux in T cells that depends on Lck since it was blocked by PP1 and absent in Lck-deficient Jurkat T cells. In wild-type Jurkat cells, Lck was activated by CD81 cross-linking, and CD81, like Lck, was found in lipid rafts. Indeed, the integrity of the raft compartment was required for the induction of a calcium flux by E2, since methyl-,-cyclodextrin abolished this response. A requirement for TCR/CD3 expression was indicated by the absence of a calcium flux following E2 stimulation of TCR/CD3-deficient Jurkat cells. CD81 cross-linking increased and prolonged the anti-CD3-induced tyrosine phosphorylation of TCR, and of other proteins, indicating that the CD81-mediated signal converges with the TCR/CD3 signaling cascade at its most upstream step. In conclusion, we propose that the costimulatory effects of HCV E2 on T cells depend on CD81 cross-linking that activates Lck through raft aggregation and thus leads to enhanced TCR signaling. [source] Autoantibodies in alcoholic liver diseaseADDICTION BIOLOGY, Issue 2 2000Ian G. McFarlane Despite many decades of research, the reasons why only a relatively small proportion of individuals who consume excessive quantities of alcohol develop clinically significant liver disease remain unknown. The association with features of autoimmune diseases, including hypergammaglobulinaemia, circulating autoantibodies, inheritance of certain immunogenetic (HLA) markers and response to corticosteroid therapy in some patients has led to a persistent impression that altered immune regulation with a relative loss of self-tolerance underlies susceptibility to the development of the more severe forms of alcoholic liver disease (alcoholic hepatitis and/or cirrhosis). However, review of the data from the numerous studies that have been conducted over the past 30 years fails to reveal sufficiently convincing evidence that autoimmunity plays a primary role in alcohol-related liver damage. In particular, most of the wide range of circulating autoantibodies that have been reported in patients are found mainly at low titres, are not confined to those with severe liver injury, and are probably more likely to be a response to the hepatic insult than causally related to liver damage. Additionally, an association with various HLA phenotypes has not been confirmed by meta-analysis. Interpretation is complicated by evidence that alcohol may have direct effects on some components of the immune system but, if there is an immunogenetic basis for alcoholic liver disease, the present evidence suggests that this might be related more to cytokine gene polymorphisms than to a predisposition to autoimmunity per se. [source] Hepatoprotective activity of picroliv, curcumin and ellagic acid compared to silymarin on paracetamol induced liver toxicity in miceFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2009C. Girish Abstract Oxidative stress is implicated as a common pathologic mechanism contributing to the initiation and progression of hepatic damage in a variety of liver disorders. Present study attempts to evaluate the hepatoprotective activity of picroliv, curcumin and ellagic acid in comparison to silymarin using paracetamol (PCM) induced acute liver damage. Hepatotoxicity was induced by administering a single oral dose of PCM (500 mg/kg) and was assessed by quantifying the serum enzyme activities, phenobarbitone induced sleeping time and histopathological analysis of liver tissues. The antioxidant parameters, malondialdehyde (MDA), reduced glutathione (GSH) and catalase of the liver tissue were also assessed. The herbal drugs were administered for 7 days by oral route at 50 and 100 mg/kg. PCM induced hepatic damage was manifested by a significant increase in the activities of marker enzymes (alanine transaminase, aspartate transaminase and alkaline phosphatase) in serum and MDA level in liver. There was also a significant decrease in activity of GSH and catalase levels. The histopathological examination on toxic models revealed centrizonal necrosis and fatty changes. Pretreatment of mice with picroliv, curcumin and ellagic acid reversed these altered parameters towards normal values, which were compared with silymarin. The normalization of phenobarbitone induced sleeping time suggests the restoration of liver cytochrome P450 enzymes. This study supports the use of these active phytochemicals against toxic liver injury, which may act by preventing the lipid peroxidation and augmenting the antioxidant defense system or regeneration of hepatocytes. These active phytochemicals may be developed as drugs for the treatment of liver diseases. [source] Assessment of drug-induced liver injury in clinical practiceFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 2 2008Ma Isabel Lucena Abstract Currently, pharmaceutical preparations are serious contributors to liver disease, with hepatotoxicity ranking as the most frequent cause for acute liver failure and post-marketing regulatory decisions. The diagnostic approach of drug-induced liver injury (DILI) is still rudimentary and inaccurate because of the lack of reliable markers for use in general clinical practice. To incriminate any given drug in an episode of liver dysfunction is a step-by-step process that requires a high degree of suspicion, compatible chronology, awareness of the drug's hepatotoxic potential, the exclusion of alternative causes of liver damage, and the ability to detect the presence of subtle data that favour a toxic aetiology. Clinical and laboratory data may also be assessed with algorithms or clinical scales, which may add consistency to the clinical judgment by translating the suspicion into a quantitative score. The CIOMS/RUCAM instrument is considered at present the best method for assessing causality in DILI, although it could be improved through the use of large database of bona fide DILI cases for validation criteria. [source] A multifaceted imbalance of T cells with regulatory function characterizes type 1 autoimmune hepatitis,,HEPATOLOGY, Issue 3 2010Silvia Ferri Immunotolerance is maintained by regulatory T cells (Tregs), including CD4+CD25hi, CD8+CD28,, ,,, and CD3+CD56+ [natural killer T (NKT)] cells. CD4+CD25hi cells are impaired in children with autoimmune hepatitis (AIH). Little is known about Tregs in adults with AIH. The aim of this study was to investigate the frequency and function of Treg subsets in adult patients with AIH during periods of active disease and remission. Forty-seven AIH patients (16 with active disease and 31 in remission) and 28 healthy controls were studied. Flow cytometry was used to evaluate surface markers and function-related intracellular molecules in ,,, CD8+CD28,, NKT, and CD4+CD25hi cells. CD4+CD25hi T cell function was determined by the ability to suppress proliferation and interferon gamma (IFN-,) production by CD4+CD25, target cells. Liver forkhead box P3,positive (FOXP3+) cells were sought by immunohistochemistry. In AIH patients, particularly during active disease, CD4+CD25hi T cells were fewer, expressed lower levels of FOXP3, and were less effective at inhibiting target cell proliferation versus healthy controls. Moreover, although the numbers of CD8+CD28, T cells were similar in AIH patients and healthy controls, NKT cells were numerically reduced, especially during active disease, and produced lower quantities of the immunoregulatory cytokine interleukin-4 versus controls. In contrast, ,, T cells in AIH patients were more numerous versus healthy controls and had an inverted V,1/V,2 ratio and higher IFN-, and granzyme B production; the latter was correlated to biochemical indices of liver damage. There were few FOXP3+ cells within the portal tract inflammatory infiltrate. Conclusion: Our data show that the defect in immunoregulation in adult AIH is complex, and ,, T cells are likely to be effectors of liver damage. (HEPATOLOGY 2010) [source] CXC chemokine ligand 4 (Cxcl4) is a platelet-derived mediator of experimental liver fibrosis,HEPATOLOGY, Issue 4 2010Mirko Moreno Zaldivar Liver fibrosis is a major cause of morbidity and mortality worldwide. Platelets are involved in liver damage, but the underlying molecular mechanisms remain elusive. Here, we investigate the platelet-derived chemokine (C-X-C motif) ligand 4 (CXCL4) as a molecular mediator of fibrotic liver damage. Serum concentrations and intrahepatic messenger RNA of CXCL4 were measured in patients with chronic liver diseases and mice after toxic liver injury. Platelet aggregation in early fibrosis was determined by electron microscopy in patients and by immunohistochemistry in mice. Cxcl4,/, and wild-type mice were subjected to two models of chronic liver injury (CCl4 and thioacetamide). The fibrotic phenotype was analyzed by histological, biochemical, and molecular analyses. Intrahepatic infiltration of immune cells was investigated by fluorescence-activated cell sorting, and stellate cells were stimulated with recombinant Cxcl4 in vitro. The results showed that patients with advanced hepatitis C virus,induced fibrosis or nonalcoholic steatohepatitis had increased serum levels and intrahepatic CXCL4 messenger RNA concentrations. Platelets were found directly adjacent to collagen fibrils. The CCl4 and thioacetamide treatment led to an increase of hepatic Cxcl4 levels, platelet activation, and aggregation in early fibrosis in mice. Accordingly, genetic deletion of Cxcl4 in mice significantly reduced histological and biochemical liver damage in vivo, which was accompanied by changes in the expression of fibrosis-related genes (Timp-1 [tissue inhibitor of matrix metalloproteinase 1], Mmp9 [matrix metalloproteinase 9], Tgf -, [transforming growth factor beta], IL10 [interleukin 10]). Functionally, Cxcl4,/, mice showed a strongly decreased infiltration of neutrophils (Ly6G) and CD8+ T cells into the liver. In vitro, recombinant murine Cxcl4 stimulated the proliferation, chemotaxis, and chemokine expression of hepatic stellate cells. Conclusion: The results underscore an important role of platelets in chronic liver damage and imply a new target for antifibrotic therapies. (HEPATOLOGY 2010.) [source] Epithelial-to-mesenchymal transitions in the liver,HEPATOLOGY, Issue 6 2009Steve S. Choi The outcome of liver injury is dictated by the effectiveness of repair. Successful repair (i.e., regeneration) results in replacement of dead epithelial cells with healthy epithelial cells, and reconstructs normal hepatic structure and function. Liver regeneration is known to involve replication of surviving mature hepatocytes and bile duct cells. This review discusses recent evidence for other mechanisms that might also replace dead hepatic epithelial cells and repair liver damage, particularly during chronic injury. According to this theory, certain epithelial cells in developing livers and/or injured adult livers undergo epithelial-to-mesenchymal transition (EMT) and move into the hepatic mesenchyme where they exhibit fibroblastic features. Some of these epithelia-derived mesenchymal cells, however, may be capable of undergoing subsequent mesenchymal-to-epithelial transition (MET), reverting to epithelial cells that ultimately become hepatocytes or cholangiocytes. Although these concepts remain to be proven, the theory predicts that the balance between EMT and MET modulates the outcome of chronic liver injury. When EMT activity outstrips MET, repair is mainly fibrogenic, causing liver fibrosis. Conversely, predominance of MET favors more normal liver regeneration. In this review, we summarize evidence that certain resident liver cells are capable of EMTs in vitro and during chronic liver injury. (HEPATOLOGY 2009.) [source] Hepatic recruitment of the inflammatory Gr1+ monocyte subset upon liver injury promotes hepatic fibrosis,HEPATOLOGY, Issue 1 2009Karlin Raja Karlmark In addition to liver-resident Kupffer cells, infiltrating immune cells have recently been linked to the development of liver fibrosis. Blood monocytes are circulating precursors of tissue macrophages and can be divided into two functionally distinct subpopulations in mice: Gr1hi (Ly6Chi) and Gr1lo (Ly6Clo) monocytes. The role of these monocyte subsets in hepatic fibrosis and the mechanisms of their differential recruitment into the injured liver are unknown. We therefore characterized subpopulations of infiltrating monocytes in acute and chronic carbon tetrachloride (CCl4)-induced liver injury in mice using flow cytometry and immunohistochemistry. Inflammatory Gr1hi but not Gr1lo monocytes are massively recruited into the liver upon toxic injury constituting an up to 10-fold increase in CD11b+F4/80+ intrahepatic macrophages. Comparing wild-type with C-C chemokine receptor (CCR2)-deficient and CCR2/CCR6,deficient mice revealed that CCR2 critically controls intrahepatic Gr1hi monocyte accumulation by mediating their egress from bone marrow. During chronic liver damage, intrahepatic CD11b+F4/80+Gr1+ monocyte-derived cells differentiate preferentially into inducible nitric oxide synthase,producing macrophages exerting proinflammatory and profibrogenic actions, such as promoting hepatic stellate cell (HSC) activation, T helper 1,T cell differentiation and transforming growth factor , (TGF-,) release. Impaired monocyte subset recruitment in Ccr2,/, and Ccr2,/,Ccr6,/, mice results in reduced HSC activation and diminished liver fibrosis. Moreover, adoptively transferred Gr1hi monocytes traffic into the injured liver and promote fibrosis progression in wild-type and Ccr2,/,Ccr6,/, mice, which are otherwise protected from hepatic fibrosis. Intrahepatic CD11b+F4/80+Gr1+ monocyte-derived macrophages purified from CCl4 -treated animals, but not naïve bone marrow monocytes or control lymphocytes, directly activate HSCs in a TGF-,,dependent manner in vitro. Conclusion: Inflammatory Gr1+ monocytes, recruited into the injured liver via CCR2-dependent bone marrow egress, promote the progression of liver fibrosis. Thus, they may represent an interesting novel target for antifibrotic strategies. (HEPATOLOGY 2009;50:261,274.) [source] Endpoints of therapy in chronic hepatitis B,HEPATOLOGY, Issue S5 2009Jordan J. Feld Because clearance of hepatitis B virus (HBV) infection is rarely, if ever, achievable, the goals of therapy necessarily focus on prevention of bad clinical outcomes. Ideally, therapies would be shown to prevent tangible clinical endpoints like development of cirrhosis, end-stage liver disease and hepatocellular carcinoma. However, these endpoints typically take years or decades to occur and are therefore impractical targets for clinical trials which last only 1-2 years. As a result, surrogate biomarkers that are believed to correlate with long-term outcome are used to evaluate therapy. Of the clinical, biochemical, serological, virological, and histological endpoints that have been evaluated, none has been shown to be ideal on its own. Symptoms are uncommon and aminotransferase levels fluctuate spontaneously. Loss of hepatitis B e antigen (HBeAg) has been the traditional therapeutic endpoint; however, the indefinite durability off treatment and the emergence of HBeAg-negative disease have made it inadequate as the sole goal of therapy. Loss of hepatitis B surface antigen is associated with improved clinical outcomes, but it is rarely achieved with current therapies. Suppression of viral replication, as measured by serum HBV DNA levels, has become the major goal of therapy, particularly if maintained off therapy. Although useful, the significance of viral levels depends on the stage of disease, degree of liver damage, and the type of therapy. Finally, liver biopsy, often considered the gold standard, is invasive, prone to sampling error, and may take years to change significantly. At present, there is no ideal biomarker for evaluation of therapies for hepatitis B. Future research should be directed at development and validation of surrogate markers that accurately predict or reflect clinically relevant outcomes of chronic hepatitis B. (HEPATOLOGY 2009;49:S96,S102.) [source] Transient elastography is unreliable for detection of cirrhosis in patients with acute liver damage,HEPATOLOGY, Issue 4 2008Ze-Zhou Song M.S. No abstract is available for this article. [source] Activation of nuclear factor E2-related factor 2 in hereditary tyrosinemia type 1 and its role in survival and tumor development,HEPATOLOGY, Issue 2 2008Silke Marhenke In tyrosinemia type 1 (HT1), accumulation of toxic metabolites results in oxidative stress and DNA damage, leading to a high incidence of hepatocellular carcinomas. Nuclear factor erythroid-2 related factor 2 (Nrf2) is a key transcription factor important for cellular protection against oxidative stress and chemical induced liver damage. To specifically address the role of Nrf2 in HT1, fumarylacetoacetate hydrolase (Fah)/Nrf2,/, mice were generated. In acute HT1, loss of Nrf2 elicited a strong inflammatory response and dramatically increased the mortality of mice. Following low grade injury, Fah/Nrf2,/, mice develop a more severe hepatitis and liver fibrosis. The glutathione and cellular detoxification system was significantly impaired in Fah/Nrf2,/, mice, resulting in increased oxidative stress and DNA damage. Consequently, tumor development was significantly accelerated by loss of Nrf2. Potent pharmacological inducers of Nrf2 such as the triterpenoid analogs 1[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole have been developed as cancer chemoprevention agents. Pretreatment with 1[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl]imidazole dramatically protected Fah,/, mice against fumarylacetoacetate (Faa)-induced toxicity. Our data establish a central role for Nrf2 in the protection against Faa-induced liver injury; the Nrf2 regulated cellular defense not only prevents acute Faa-induced liver failure but also delays hepatocarcinogenesis in HT1. (HEPATOLOGY 2008;48:487,496.) [source] Critical role of acidic sphingomyelinase in murine hepatic ischemia-reperfusion injury,HEPATOLOGY, Issue 3 2006Laura Llacuna The molecular mechanisms of hepatic ischemia/reperfusion (I/R) damage are incompletely understood. We investigated the role of ceramide in a murine model of warm hepatic I/R injury. This sphingolipid induces cell death and participates in tumor necrosis factor (TNF) signaling. Hepatic ceramide levels transiently increased after the reperfusion phase of the ischemic liver in mice, because of an early activation of acidic sphingomyelinase (ASMase) followed by acid ceramidase stimulation. In vivo administration of an ASMase inhibitor, imipramine, or ASMase knockdown by siRNA decreased ceramide generation during I/R, and attenuated serum ALT levels, hepatocellular necrosis, cytochrome c release, and caspase-3 activation. ASMase-induced ceramide generation activated JNK resulting in BimL phosphorylation and translocation to mitochondria, as the inhibition of ASMase by imipramine prevented these events. In contrast, blockade of ceramide catabolism by N-oleyolethanolamine (NOE), a ceramidase inhibitor, enhanced ceramide levels and potentiated I/R injury compared with vehicle-treated mice. Pentoxifylline treatment prevented TNF upregulation and ASMase activation. Furthermore, 9 of 11 mice treated with imipramine survived 7 days after total liver ischemia, compared with 4 of 12 vehicle-treated mice, whereas 8 of 8 NOE-treated mice died within 2 days of total liver ischemia. In conclusion, ceramide generated from ASMase plays a key role in I/R-induced liver damage, and its modulation may be of therapeutic relevance. (HEPATOLOGY 2006.) [source] Do alcohol-metabolizing enzyme gene polymorphisms increase the risk of alcoholism and alcoholic liver disease?,HEPATOLOGY, Issue 2 2006Elias Zintzaras Case,control studies that have investigated the association between alcoholism and alcohol-induced liver damage and the ADH2, ADH3, CYP2E1, and ADLH2 polymorphisms have reported controversial or inconclusive results. Thus, we conducted a meta-analysis of 50 association studies of the above polymorphisms. We explored potential sources of heterogeneity and bias, performed subgroup analyses by racial background and sex, performed sensitivity analyses for studies not in Hardy-Weinberg equilibrium, and performed a subgroup analysis for cases that met strict criteria for alcoholism. The present meta-analysis underscores significant associations of ADH2*1, ADH3*2, and ALDH2*1 alleles and the risk of alcoholism (OR = 1.89 [95% CI 1.56,2.28], 1.32 [95% CI 1.12,1.57], and 4.35 [95% CI 3.04,6.23], respectively). The subsequent subgroup analyses showed association for ADH2*1 and ADH3*2 only in East Asians (OR = 2.23 [95% CI 1.81,2.74] and 1.91 [95% CI 1.45,2.53], respectively) and East Asian males (OR = 2.21 [95% CI 1.57,3.10], 1.69 [95% CI 1.10,2.59], respectively). In East Asian males, the OR for ALDH2*1 was 3.66 (95% CI 1.68,7.96). In Caucasians, sensitivity analysis revealed an association for ADH2*1 in alcoholism (OR = 1.62 [95% CI 1.22,1.89]). When strict criteria were imposed, the pattern of results remained unaltered. For liver disease, there were no significant associations for ADH2*1, ADH3*2, or ALDH2*1 in all subpopulations. The CYP2E1 polymorphism showed no association whatsoever. There is evidence that alleles are mainly dominant. In conclusion, there was heterogeneity between studies in alcoholism for ADH2, ADH3, and ALDH2, and lack of bias in all polymorphisms. The above findings reinforce the need for more rigorous studies, and for regular synthesis of studies' results. (HEPATOLOGY 2006;43:352,361.) [source] Combined loss of orphan receptors PXR and CAR heightens sensitivity to toxic bile acids in mice,HEPATOLOGY, Issue 1 2005Hirdesh Uppal Efficient detoxification of bile acids is necessary to avoid pathological conditions such as cholestatic liver damage and colon cancer. The orphan nuclear receptors PXR and CAR have been proposed to play an important role in the detoxification of xeno- and endo-biotics by regulating the expression of detoxifying enzymes and transporters. In this report, we showed that the combined loss of PXR and CAR resulted in a significantly heightened sensitivity to bile acid toxicity in a sex-sensitive manner. A regimen of lithocholic acid treatment, which was tolerated by wild-type and PXR null mice, caused a marked accumulation of serum bile acids and histological liver damage as well as an increased hepatic lipid deposition in double knockout males. The increased sensitivity in males was associated with genotype-specific suppression of bile acid transporters and loss of bile acid,mediated downregulation of small heterodimer partner, whereas the transporter suppression was modest or absent in females. The double knockout mice also exhibited gene- and tissue-specific dysregulation of PXR and CAR target genes in response to PXR and CAR agonists. In conclusion, although the cross-regulation of target genes by PXR and CAR has been proposed, the current study represents in vivo evidence of the combined loss of both receptors causing a unique pattern of gene regulation that can be translated into physiological events such as sensitivity to toxic bile acids. (HEPATOLOGY 2005;41:168,176.) [source] Detection of apoptotic caspase activation in sera from patients with chronic HCV infection is associated with fibrotic liver injuryHEPATOLOGY, Issue 5 2004Heike Bantel Chronic hepatitis C virus (HCV) infection is characterized by inflammatory liver damage and is associated with a high risk of development of cirrhosis and hepatocellular carcinoma. Although histological examination of liver biopsies is currently the gold standard for the detection of early liver damage, there is a strong need for better noninvasive methods. We recently demonstrated that the proapoptotic activation of caspases is considerably enhanced in histological sections from HCV-infected liver tissue, suggesting an important role of apoptosis in liver damage. Here, we investigated whether caspase activation is detectable also in sera from patients with chronic HCV infection. Using a novel enzyme-linked immunosorbent assay that selectively recognizes a proteolytic neoepitope of the caspase substrate cytokeratin-18, we demonstrate that caspase activity is markedly increased in the sera of HCV patients. Interestingly, while 27% of patients with chronic HCV infection showed normal aminotransferase levels despite inflammatory and fibrotic liver damage, more than 50% of those patients exhibited already elevated serum caspase activity. Moreover, 30% of patients with normal aminotransferase but elevated caspase activity revealed higher stages of fibrosis. In conclusion, compared with conventional surrogate markers such as aminotransferases, detection of caspase activity in serum might be a more sensitive method of detecting early liver injury. Thus, measurement of caspase activity might provide a novel diagnostic tool, especially for patients with normal aminotransferases but otherwise undiagnosed histologically active hepatitis and progressive fibrosis. (HEPATOLOGY 2004;40:1078,1087.) [source] Leflunomide protects from T-cell,mediated liver injury in mice through inhibition of nuclear factor ,BHEPATOLOGY, Issue 5 2004Motoaki Imose Leflunomide is a novel immunosuppressive and anti-inflammatory agent for the treatment of autoimmune disease. The aim of this study was to investigate whether leflunomide protects from liver injury induced by concanavalin A (Con A), a T-cell,dependent model of liver damage. BALB/c mice were injected with 25 mg/kg Con A in the presence or absence of 30 mg/kg leflunomide. Liver injury was assessed biochemically and histologically. Levels of circulating cytokines and expressions of cytokine messenger RNA (mRNA) in the liver and the spleen were determined. Treatment with leflunomide markedly reduced serum transaminase activities and the numbers of dead liver cells. Leflunomide significantly inhibited increases in plasma tumor necrosis factor alpha (TNF-,) and interleukin 2 concentrations, and also reduced TNF-, mRNA expression in the liver after administration of Con A. These findings were supported by the results in which leflunomide administration decreased the number of T lymphocytes infiltrating the liver as well as inhibiting their production of TNF-,. Activation of nuclear factor ,B (NF-,B), which regulates TNF-, production, was inhibited in the liver of mice treated with leflunomide, resulting in a reduction of TNF-, production from lymphocytes infiltrating the liver. In conclusion, leflunomide is capable of regulating T-cell,mediated liver injury in vivo and that this event may depend on the decrease of TNF-, production in the liver through inhibition of NF-,B activation caused by leflunomide. (HEPATOLOGY 2004.) [source] The nuclear bile acid receptor FXR as a novel therapeutic target in cholestatic liver diseases: Hype or hope?HEPATOLOGY, Issue 1 2004Michael Trauner M.D. Farnesoid X receptor (FXR) is a bile acid,activated transcription factor that is a member of the nuclear hormone receptor superfamily. FXR-null mice exhibit a phenotype similar to Byler disease, an inherited cholestatic liver disorder. In the liver, activation of FXR induces transcription of transporter genes involved in promoting bile acid clearance and represses genes involved in bile acid biosynthesis. We investigated whether the synthetic FXR agonist GW4064 could protect against cholestatic liver damage in rat models of extrahepatic and intrahepatic cholestasis. In the bile duct ligation and alpha-naphthylisothiocyanate models of cholestasis, GW4064 treatment resulted in significant reductions in serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase, as well as other markers of liver damage. Rats that received GW4064 treatment also had decreased incidence and extent of necrosis, decreased inflammatory cell infiltration, and decreased bile duct proliferation. Analysis of gene expression in livers from GW4064-treated cholestatic rats revealed decreased expression of bile acid biosynthetic genes and increased expression of genes involved in bile acid transport, including the phospholipid flippase MDR2. The hepatoprotection seen in these animal models by the synthetic FXR agonist suggests FXR agonists may be useful in the treatment of cholestatic liver disease. [source] BSEP and MDR3 haplotype structure in healthy Caucasians, primary biliary cirrhosis and primary sclerosing cholangitisHEPATOLOGY, Issue 3 2004Christiane Pauli-Magnus Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are characterized by a cholestatic pattern of liver damage, also observed in hereditary or acquired dysfunction of the canalicular membrane transporters bile salt export pump (BSEP, ABCB11) and multidrug resistance protein type 3 (MDR3, ABCB4). Controversy exists whether a genetically determined dysfunction of BSEP and MDR3 plays a pathogenic role in PBC and PSC. Therefore, 149 healthy Caucasian control individuals (control group) were compared to 76 PBC and 46 PSC patients with respect to genetic variations in BSEP and MDR3. Sequencing spanned ,10,000 bp including promoter and coding regions as well as 50,350 bp of flanking intronic regions. In all, 46 and 45 variants were identified in BSEP and MDR3, respectively. No differences between the groups were detected either in the total number of variants (BSEP: control group: 37, PBC: 37, PSC: 31; and MDR3: control group: 35; PBC: 32, PSC: 30), or in the allele frequency of the common variable sites. Furthermore, there were no significant differences in haplotype distribution and linkage disequilibrium. In conclusion, this study provides an analysis of BSEP and MDR3 variant segregation and haplotype structure in a Caucasian population. Although an impact of rare variants on BSEP and MDR3 function cannot be ruled out, our data do not support a strong role of BSEP and MDR3 genetic variations in the pathogenesis of PBC and PSC. (HEPATOLOGY 2004;39:779,791.) [source] Chronic liver disease in murine hereditary tyrosinemia type 1 induces resistance to cell deathHEPATOLOGY, Issue 2 2004Arndt Vogel The murine model of hereditary tyrosinemia type 1 (HT1) was used to analyze the relationship between chronic liver disease and programmed cell death in vivo. In healthy fumarylacetoacetate hydrolase deficient mice (Fah -/- ), protected from liver injury by the drug 2-(2- nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC), the tyrosine metabolite homogentisic acid (HGA) caused rapid hepatocyte death. In contrast, all mice survived the same otherwise lethal dose of HGA if they had preexisting liver damage induced by NTBC withdrawal. Similarly, Fah -/- animals with liver injury were also resistant to apoptosis induced by the Fas ligand Jo-2 and to necrosis-like cell death induced by acetaminophen (APAP). Molecular studies revealed a marked up-regulation of the antiapoptotic heat shock proteins (Hsp) 27, 32, and 70 and of c-Jun in hepatocytes of stressed mice. In addition, the p38 and Jun N-terminal kinase (JNK) stress-activated kinase pathways were markedly impaired in the cell-death resistant liver. In conclusion, these results provide evidence that chronic liver disease can paradoxically result in cell death resistance in vivo. Stress-induced failure of cell death programs may lead to an accumulation of damaged cells and therefore enhance the risk for cancer as observed in HT1 and other chronic liver diseases. (HEPATOLOGY 2004;39:433,443.) [source] Role of V, 14 NKT cells in the development of impaired liver regeneration in vivoHEPATOLOGY, Issue 5 2003Hiroyasu Ito Although we have previously demonstrated that IL-12 stimulation increases the number of hepatic natural killer (NK) T (NKT) cells and enhances liver injury during the early phase of liver regeneration, the role of NKT cells has remained unknown. We therefore evaluated the influence of NKT cells activated by IL-12 or by ,-galactosylceramide (,-GalCer) on murine liver regeneration using V, 14 NKT knockout (J, 281,/,) mice. Levels of serum alanine aminotransferase (sALT) 24 hours after partial hepatectomy were enhanced in J, 281+/+ but not in J, 281,/, mice by both procedures. Hepatic NKT cells expressed considerably more interferon (IFN) , and tumor necrosis factor , (TNF-,) messenger RNA (mRNA) after stimulation with both factors in J, 281+/+ mice. Either anti-IFN-, or TNF-, antibody inhibited the enhancement of liver injury. Furthermore, recombinant TNF-, injection similarly caused injury in hepatectomized livers of both J, 281+/+ and J, 281,/, mice; indeed, adoptively transferred TNF-,+/+ NKT cells enhanced liver injury after hepatectomy in TNF-, knockout mice. TNF receptor expressions on hepatocytes increased and peaked 24 hours after partial hepatectomy. In conclusion, simultaneous TNF-, synthesis and high levels of TNF receptor expression on hepatocytes cause severe liver damage by activated NKT cells during liver regeneration. [source] Alcohol potentiates hepatitis C virus replicon expressionHEPATOLOGY, Issue 1 2003Ting Zhang Alcohol consumption accelerates liver damage and diminishes the anti-hepatitis C virus (HCV) effect of interferon alfa (IFN-,) in patients with HCV infection. It is unknown, however, whether alcohol enhances HCV replication and promotes HCV disease progression. The availability of the HCV replicon containing hepatic cells has provided a unique opportunity to investigate the interaction between alcohol and HCV replicon expression. We determined whether alcohol enhances HCV RNA expression in the replicon containing hepatic cells. Alcohol, in a concentration-dependent fashion, significantly increased HCV replicon expression. Alcohol also compromised the anti-HCV effect of IFN-,. Investigation of the mechanism(s) responsible for the alcohol action on HCV replicon indicated that alcohol activated nuclear factor ,B (NF-,B) promoter. Caffeic acid phenethyl ester (CAPE), a specific inhibitor of the activation of NF-,B, abolished alcohol-induced HCV RNA expression. In addition, naltrexone, an opiate receptor antagonist, abrogated the enhancing effect of alcohol on HCV replicon expression. In conclusion, alcohol, probably through the activation of NF-,B and the endogenous opioid system, enhances HCV replicon expression and compromises the anti-HCV effect of IFN-,. Thus, alcohol may play an important role in vivo as a cofactor in HCV disease progression and compromise IFN-,-based therapy against HCV infection. [source] Caspase activation correlates with the degree of inflammatory liver injury in chronic hepatitis C virus infectionHEPATOLOGY, Issue 4 2001Heike Bantel Hepatitis C virus (HCV) infection is a major cause of liver disease characterized by inflammation, cell damage, and fibrotic reactions of hepatocytes. Apoptosis has been implicated in the pathogenesis, although it is unclear whether proteases of the caspase family as the central executioners of apoptosis are involved and how caspase activation contributes to liver injury. In the present study, we measured the activation of effector caspases in liver biopsy specimens of patients with chronic HCV infection. The activation of caspase-3, caspase-7, and cleavage of poly(ADP-ribose)polymerase (PARP), a specific caspase substrate, were measured by immunohistochemistry and Western blot analysis by using antibodies that selectively detect the active truncated, but not the inactive precursor forms of the caspases and PARP. We found that caspase activation was considerably elevated in liver lobules of HCV patients in comparison to normal controls. Interestingly, the immunoreactive cells did yet not reveal an overt apoptotic morphology. The extent of caspase activation correlated significantly with the disease grade, i.e., necroinflammatory activity. In contrast, no correlation was observed with other surrogate markers such as serum transaminases and viral load. In biopsy specimens with low activity (grade 0) 7.7% of the hepatocytes revealed caspase-3 activation, whereas 20.9% of the cells stained positively in grade 3. Thus, our results suggest that caspase activation is involved in HCV-associated liver injury. Moreover, measurement of caspase activity may represent a reliable marker for the early detection of liver damage, which may open up new diagnostic and therapeutic strategies in HCV infection. [source] Characteristics of hepatocellular carcinoma in a murine model of alpha-1-antitrypsin deficiencyHEPATOLOGY RESEARCH, Issue 6 2010Nancy Y. Marcus Aim:, Individuals with homozygous (ZZ) alpha-1-antitrypsin (,1AT) deficiency are at an increased risk for liver damage, cirrhosis and hepatocellular carcinoma (HCC). The transgenic PiZ mouse, expressing the human ,1AT mutant Z gene, is a valuable model for this disease. We studied PiZ mice in order to identify and characterize mechanisms involved in the development of HCC. Methods:, Tumor incidence and histology were studied, gene expression levels were surveyed with microarrays, RNA quantified with quantitative real time polymerase chain reaction and protein levels determined with immunoblots and immunohistochemistry. Results:, By 16,19 months of age, approximately 69% of the PiZ mice had developed tumors. HCC was present with no evidence of benign adenomas as pre-cancerous lesions. Tumors showed abnormal mitochondria, variable levels of steatosis, globular inclusions of ,1AT mutant Z protein and metastases. PiZ mice that subsequently developed liver tumors had higher serum levels of ,1AT mutant Z protein than those that did not develop tumors. Cyclin D1, a cell cycle protein, was upregulated in PiZ livers without tumors compared to Wt. cFOS, a component of AP-1 that may be involved in transforming cells and MCAM, an adhesion molecule likely involved in tumorigenesis and metastases, were elevated in tumors compared with livers without tumors. Conclusion:, In the PiZ model, many of the histological characteristics of HCC recapitulated features seen in human HCC, whether from individuals with homozygous ZZ liver disease or from unrelated causes in individuals that were not homozygous ZZ. The accumulation of mutant Z protein altered the regulation of several genes driving proliferation and tumorigenesis. [source] | |||||||||||||||||||||||||||||||||||||||||||