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1.
Alcohol Clin Exp Res ; 37(10): 1771-8, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23875541

ABSTRACT

BACKGROUND: A reliable biomarker is required in hepatology clinics for detection and follow-up of heavy alcohol consumption. Carbohydrate-deficient transferrin (CDT) increases with sustained heavy alcohol consumption and is the most specific biomarker of ethanol (EtOH) consumption. Recent introduction of a standardized method for measuring CDT has improved its clinical application. This study was designed to determine whether alcohol-independent factors influence CDT levels in patients with chronic liver disease (CLD). METHODS: The relationship between serum %CDT and self-reported history of alcohol consumption was examined in 254 patients referred for evaluation of liver disease. CDT analysis was performed on serum collected at time of liver biopsy. RESULTS: CDT levels were not affected by severity or etiology of nonalcoholic liver disease. Thirteen of 254 subjects had a %CDT >1.7, predictive of heavy alcohol intake, 6 of whom did not acknowledge heavy drinking. Twelve of these 13 subjects were suspected heavy drinkers on review of their medical records and clinical results. Conversely, not all acknowledged heavy drinkers had %CDT >1.7. Heavy drinkers with a body mass index (BMI) in the overweight or obese range had significantly lower %CDT than lean heavy drinkers. This persisted even when lean body weight was used as an approximation of the EtOH volume of distribution. CONCLUSIONS: An elevated BMI reduces the diagnostic utility of CDT at higher alcohol intake in subjects with CLD using the standardized method. In a hepatology outpatient setting, this assay is likely to be useful to confirm suspicion of heavy drinking in subjects who are not overweight, but cannot reliably identify moderate drinkers or heavy drinkers who are overweight.


Subject(s)
Alcohol Drinking/blood , Body Mass Index , Liver Diseases/blood , Liver Diseases/diagnosis , Transferrin/analogs & derivatives , Adult , Alcohol Drinking/epidemiology , Biomarkers/blood , Cohort Studies , Female , Humans , Liver Diseases/epidemiology , Male , Middle Aged , Transferrin/metabolism
2.
Liver Int ; 33(4): 624-32, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23356584

ABSTRACT

BACKGROUND: Adult non-alcoholic fatty liver disease (NAFLD) involves lobular necroinflammatory activity and fibrosis is typically centrilobular, whereas paediatric NAFLD has predominantly portal fibrosis. The reasons for these differences are unclear. We aimed to determine (a) how centrilobular and portal fibrosis in children relate to histological parameters; and (b) whether atypical fibrosis patterns exist in adults that are unexplained by current fibrogenesis models. METHODS: Histological features of paediatric (n = 38) and adult (n = 56) NAFLD were assessed using conventional scoring systems. Keratin-7 immunostaining was used to assess hepatic progenitor cell numbers and the ductular reaction. Centrilobular and portal components of fibrosis were independently scored and fibrosis patterns were classified according to accepted types. Post-treatment (rosiglitazone/gastric banding) biopsies were also examined in adults. RESULTS: Twenty-six children (68.4%) had portal-predominant fibrosis, although the typical "adult" pattern was seen in 11 (28.9%). Portal fibrosis was associated with a ductular reaction (P = 0.021) and hepatic progenitor cell expansion (P < 0.001), whereas centrilobular fibrosis was associated with lobular inflammation (P = 0.026) and ballooning (P = 0.001). Before intervention, six adults (10.7%) had atypical fibrosis including 3 (5.4%) with a previously unrecognized pattern of very fine, non-zonal sinusoidal fibrosis. Despite improvements in steatosis and inflammation, more patients developed this unusual pattern after intervention with most having had surgery (9 of 10 adults; P < 0.001). CONCLUSION: Differing associations with portal and centrilobular fibrosis in children and atypical fibrosis patterns in adults suggest that multiple fibrogenic pathways exist in NAFLD. This has implications for therapy and understanding pathogenesis.


Subject(s)
Fatty Liver/complications , Liver Cirrhosis/etiology , Liver/pathology , Adolescent , Adult , Age Factors , Australia , Bile Ducts, Intrahepatic/chemistry , Bile Ducts, Intrahepatic/pathology , Biomarkers/analysis , Biopsy , Cell Proliferation , Child , Child, Preschool , Europe , Fatty Liver/metabolism , Fatty Liver/pathology , Fatty Liver/therapy , Gastric Bypass , Humans , Immunohistochemistry , Keratin-7/analysis , Liver/chemistry , Liver/drug effects , Liver Cirrhosis/classification , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Liver Cirrhosis/therapy , Missouri , Non-alcoholic Fatty Liver Disease , Risk Factors , Rosiglitazone , Stem Cells/chemistry , Stem Cells/pathology , Thiazolidinediones/therapeutic use , Treatment Outcome
3.
Liver Int ; 33(4): 569-79, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23240894

ABSTRACT

BACKGROUND: Liver macrophages are a heterogeneous cell population that produces factors involved in fibrogenesis and matrix turnover, including matrix metalloproteinase (MMP) -9. During liver injury, their close proximity to hepatic progenitor cells and the ductular reaction may enable them to regulate liver repair and fibrosis. AIMS: To enumerate and characterise liver macrophages in patients with chronic hepatitis C, to determine whether a distinct population of macrophages is associated with the ductular reaction and portal fibrosis. METHODS: Immunostaining for macrophage markers (CD68, CD163, CCR2), the ductular reaction (keratin-7) and MMP-9 was performed in liver biopsy sections from patients with chronic hepatitis C virus (HCV) (n = 85). RESULTS: Portal tracts were more densely populated with macrophages (10.5 ± 0.36 macrophages/HPF) than lobules (7.2 ± 0.16 macrophages/HPF, P < 0.001) and macrophages were found in close proximity to the ductular reaction. ≥30% of portal and periductal macrophages expressed MMP-9 and these were significantly associated with increasing stage of fibrosis (rs  = 0.58, 0.68, respectively, both P < 0.001). In contrast, MMP-9(+) macrophages were largely absent in lobular regions and non-diseased liver. Hepatic MMP-9 mRNA levels and gelatinolytic activity were significantly associated with stage of fibrosis (rs  = 0.47, rs  = 0.89, respectively, both P < 0.001). Furthermore, a second distinct CCR2(+) macrophage population was localised to the centrilobular regions and was predominantly absent from portal and periductal areas. CONCLUSIONS: These findings demonstrate significant regional differences in macrophage phenotypes, suggesting that there are at least two populations of liver macrophages. We propose that these populations have distinct contributions to the pathogenesis of chronic HCV-related liver disease.


Subject(s)
Bile Ducts, Intrahepatic/enzymology , Hepatitis C, Chronic/enzymology , Liver Cirrhosis/enzymology , Liver/enzymology , Macrophages/enzymology , Matrix Metalloproteinase 9/analysis , Adult , Aged , Analysis of Variance , Antigens, CD/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Bile Ducts, Intrahepatic/immunology , Bile Ducts, Intrahepatic/pathology , Bile Ducts, Intrahepatic/virology , Biomarkers/analysis , Biopsy , Female , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/genetics , Hepatitis C, Chronic/immunology , Hepatitis C, Chronic/pathology , Humans , Immunohistochemistry , Keratin-7/analysis , Liver/immunology , Liver/pathology , Liver/virology , Liver Cirrhosis/genetics , Liver Cirrhosis/immunology , Liver Cirrhosis/pathology , Liver Cirrhosis/virology , Macrophages/immunology , Male , Matrix Metalloproteinase 9/genetics , Middle Aged , Phenotype , RNA, Messenger/analysis , Receptors, CCR2/analysis , Receptors, Cell Surface/analysis , Severity of Illness Index , Young Adult
4.
Liver Int ; 32(9): 1391-9, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22676252

ABSTRACT

BACKGROUND: Serum hepcidin concentration is potentially affected by inflammation and iron stores in chronic liver disease (CLD), but little is known about the relationship between hepcidin and the degree of hepatic fibrosis. We investigated the potential role of serum hepcidin as a biomarker of advanced liver disease. METHODS: Serum hepcidin was measured in 332 adults with CLD of varying aetiologies, 45 healthy and 50 non-liver disease patient controls. Liver biopsy data were available for 228 CLD subjects. RESULTS: Hepcidin was decreased in CLD patients compared with non-liver disease patient controls (P < 0.0001) but not healthy controls, and was lowest in those with cirrhosis (P < 0.0001). Serum hepcidin correlated with hepatic hepcidin mRNA expression in 91 biopsy samples available for genetic analysis (r = 0.68, P < 0.0001). Hepcidin also correlated positively with serum ferritin concentration, transferrin saturation, ALT, serum albumin and haemoglobin, but negatively with serum bilirubin. The hepcidin:ferritin ratio was significantly lower in CLD subjects compared with healthy and disease controls, and decreased with each increase in the stage of fibrosis and siderosis. The hepcidin:ferritin ratio was associated with progressive fibrosis on linear regression, and a value of less than 0.1 was independently associated with cirrhosis on logistic regression analyses (OR 5.54, P < 0.001). Receiver operating characteristic analysis showed the hepcidin:ferritin ratio was able to distinguish between F0 and F4 stages of fibrosis (area under receiver operating characteristic curve = 0.86). CONCLUSIONS: The hepcidin:ferritin ratio is reduced in relation to increasing fibrosis in CLD and the use of this ratio may have potential future diagnostic implications as a marker of cirrhosis.


Subject(s)
Antimicrobial Cationic Peptides/blood , Biomarkers/metabolism , Ferritins/blood , Liver Cirrhosis/metabolism , Adult , Alanine Transaminase/blood , Antimicrobial Cationic Peptides/genetics , Bilirubin/blood , Chronic Disease , Disease Progression , Female , Ferritins/genetics , Gene Expression , Hemoglobins/analysis , Hepcidins , Humans , Liver/metabolism , Liver/pathology , Liver Cirrhosis/diagnosis , Liver Cirrhosis/genetics , Liver Failure/diagnosis , Liver Failure/genetics , Liver Failure/metabolism , Liver Function Tests , Male , Middle Aged , Predictive Value of Tests , ROC Curve , Serum Albumin/analysis , Transferrins/blood
5.
World J Gastroenterol ; 18(15): 1732-44, 2012 Apr 21.
Article in English | MEDLINE | ID: mdl-22553397

ABSTRACT

AIM: To investigate the influence of macrophages on hepatocyte phenotype and function. METHODS: Macrophages were differentiated from THP-1 monocytes via phorbol myristate acetate stimulation and the effects of monocyte or macrophage-conditioned medium on HepG2 mRNA and protein expression determined. The in vivo relevance of these findings was confirmed using liver biopsies from 147 patients with hepatitis C virus (HCV) infection. RESULTS: Conditioned media from macrophages, but not monocytes, induced a transient morphological change in hepatocytes associated with upregulation of vimentin (7.8 ± 2.5-fold, P = 0.045) and transforming growth factor (TGF)-ß1 (2.6 ± 0.2-fold, P < 0.001) and downregulation of epithelial cadherin (1.7 ± 0.02-fold, P = 0.017) mRNA expression. Microarray analysis revealed significant upregulation of lipocalin-2 (17-fold, P < 0.001) and pathways associated with inflammation, and substantial downregulation of pathways related to hepatocyte function. In patients with chronic HCV, real-time polymerase chain reaction and immunohistochemistry confirmed an increase in lipocalin-2 mRNA (F0 1.0 ± 0.3, F1 2.2 ± 0.2, F2 3.0 ± 9.3, F3/4 4.0 ± 0.8, P = 0.003) and protein expression (F1 1.0 ± 0.5, F2 1.3 ± 0.4, F3/4 3.6 ± 0.4, P = 0.014) with increasing liver injury. High performance liquid chromatography-tandem mass spectrometry analysis identified elevated levels of matrix metalloproteinase (MMP)-9 in macrophage-conditioned medium, and a chemical inhibitor of MMP-9 attenuated the change in morphology and mRNA expression of TGF-ß1 (2.9 ± 0.2 vs 1.04 ± 0.1, P < 0.001) in macrophage-conditioned media treated HepG2 cells. In patients with chronic HCV infection, hepatic mRNA expression of CD163 (F0 1.0 ± 0.2, F1/2 2.8 ± 0.3, F3/4 5.3 ± 1.0, P = 0.001) and MMP-9 (F0 1.0 ± 0.4, F1/2 2.8 ± 0.3, F3/4 4.1 ± 0.8, P = 0.011) was significantly associated with increasing stage of fibrosis. CONCLUSION: Secreted macrophage products alter the phenotype and function of hepatocytes, with increased expression of inflammatory mediators, suggesting that hepatocytes actively participate in liver injury.


Subject(s)
Hepatocytes/physiology , Inflammation Mediators/metabolism , Macrophages/physiology , Acute-Phase Proteins/physiology , Antigens, CD/physiology , Antigens, Differentiation, Myelomonocytic/physiology , Gene Expression Profiling , Hep G2 Cells , Humans , Lipocalin-2 , Lipocalins/physiology , Liver Cirrhosis/metabolism , Matrix Metalloproteinase 9/physiology , Phenotype , Proto-Oncogene Proteins/physiology , RNA, Messenger/analysis , Receptors, Cell Surface/physiology
6.
Hepatology ; 53(6): 1819-29, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21381070

ABSTRACT

UNLABELLED: Interleukin 32 (IL-32) is a recently described proinflammatory cytokine that activates p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB), thereby inducing proinflammatory cytokines such as IL-1ß and tumor necrosis factor alpha (TNF-α). We investigated the role of IL-32 in patients with chronic hepatitis C virus (HCV) infection. Steady-state hepatic messenger RNA (mRNA) levels of IL-32 were determined in a cohort of 90 subjects; anti-IL-32 staining was used in a second cohort of 132 consecutive untreated chronic HCV patients. Correlations with histological features of steatosis, inflammation, and fibrosis were made. In vitro, endogenous IL-32 in monocytes and in the human hepatoma cell line Huh-7.5 were examined. The effects of IL-32-overexpression and IL-32-silencing on HCV replication were studied using HCV luciferase reporter viruses. There were highly significant positive associations between hepatic IL-32 mRNA expression and liver steatosis, inflammation, fibrosis, smooth muscle actin (SMA) area, and serum alanine aminotransferase (ALT) levels. IL-32 protein expression was positively associated with portal inflammation, SMA area, and ALT. In vitro, IL-1ß and TNF-α significantly induced IL-32 expression in human Huh-7.5 cells. Alone, stimulation with interferon alpha (IFN-α) did not induce IL-32 expression in Huh-7.5. However, IFN-α exerted a significant additive effect on TNF-α-induced but not IL-1ß-induced IL-32 expression, particularly in CD14+ monocytes. This effect was dependent both on NF-κB and Jak/STAT signaling. Viral infection of Huh-7.5 cells resulted in a significant (11-fold) induction of IL-32 mRNA expression. However, modulation of IL-32 in Huh-7.5 cells by overexpression or silencing did not influence HCV virus replication as determined by luciferase assays. CONCLUSION: IL-32 is a novel proinflammatory cytokine involved in HCV-associated liver inflammation/fibrosis. IL-32 is expressed by human hepatocytes and hepatoma cells and its expression is regulated by proinflammatory stimuli.


Subject(s)
Hepatitis C, Chronic/metabolism , Hepatitis C, Chronic/pathology , Interleukins/metabolism , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Adult , Biopsy , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/virology , Cell Line, Tumor , Cohort Studies , Female , Gene Expression Regulation/drug effects , Hepacivirus/physiology , Hepatocytes/drug effects , Hepatocytes/metabolism , Hepatocytes/pathology , Humans , Interferon-alpha/pharmacology , Interleukin-1beta/pharmacology , Liver/metabolism , Liver/pathology , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , Liver Neoplasms/virology , Male , Middle Aged , Retrospective Studies , Tumor Necrosis Factor-alpha/pharmacology , Virus Replication/physiology
7.
J Gastroenterol Hepatol ; 26(2): 319-27, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21261722

ABSTRACT

BACKGROUND AND AIM: Hepatitis C virus (HCV) proteins activate the unfolded protein response (UPR) in experimental models. The role of the UPR in the pathogenesis of HCV-induced liver injury has not been determined. Our aim was to investigate the role of the UPR in the pathogenesis of chronic HCV. METHODS: Liver biopsy samples from 124 patients with chronic HCV and 24 HCV/HBV-negative subjects with histologically normal liver (NDL) were assessed. The hepatic mRNA expression of components of the UPR was measured by semi-quantitative real-time polymerase chain reaction. Glucose regulated protein (GRP) 78 protein expression was assessed by immunohistochemistry. RESULTS: The expression of GRP78 mRNA and growth arrest and damage inducible protein 34 (GADD34) mRNA was significantly lower in subjects with HCV than NDL (P = 0.007 and P < 0.001, respectively). There was no significant difference in the expression of GRP94 mRNA, spliced X box binding protein 1 (sXBP1) mRNA, C/EBP homologous protein mRNA (CHOP) and ER degradation enhancing α-mannosidase-like protein (EDEM) mRNA and GRP78 protein between patients with HCV and NDL. There were no relationships between elements of the UPR and inflammation or fibrosis in patients with HCV. CONCLUSION: Downstream components of UPR were not activated in patients with chronic HCV. Therefore, the UPR may not play a prominent role in liver injury in patients with chronic HCV infection.


Subject(s)
Hepatitis C, Chronic/metabolism , Liver/metabolism , Unfolded Protein Response , Activating Transcription Factor 6/metabolism , Adult , Antigens, Differentiation/genetics , Biopsy , Case-Control Studies , Cell Cycle Proteins/genetics , Chi-Square Distribution , DNA-Binding Proteins/genetics , Endoplasmic Reticulum Chaperone BiP , Endoribonucleases/metabolism , Female , Gene Expression Regulation , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism , Hepatitis C, Chronic/genetics , Hepatitis C, Chronic/pathology , Humans , Immunohistochemistry , Liver/pathology , Liver/virology , Male , Protein Phosphatase 1 , Protein Serine-Threonine Kinases/metabolism , Queensland , RNA, Messenger/metabolism , Regulatory Factor X Transcription Factors , Reverse Transcriptase Polymerase Chain Reaction , Transcription Factor CHOP/genetics , Transcription Factors/genetics , Unfolded Protein Response/genetics , eIF-2 Kinase/metabolism
9.
Dig Dis ; 28(1): 186-91, 2010.
Article in English | MEDLINE | ID: mdl-20460909

ABSTRACT

Over the last few years, the paradigm in hepatology has changed from focusing on a single liver disease to considering concurrent diseases, in particular obesity and related metabolic factors. Obesity has reached epidemic proportions globally and is associated with insulin resistance, steatosis and a low-grade systemic inflammatory state. These metabolic factors have a synergistic role in the natural history and treatment outcomes related to chronic liver disease. This is characterized best in chronic hepatitis C where steatosis and insulin resistance are caused by viral and metabolic effects. Non-alcoholic fatty liver disease and related metabolic abnormalities also exacerbate other diseases, such as alcoholic liver disease and haemochromatosis. In addition, there is growing evidence linking obesity and type 2 diabetes with hepatocellular carcinoma in subjects with chronic viral hepatitis. The pathogenesis of co-morbid disease may be related to increased oxidative stress, inflammatory injury and cell death, along with altered hepatocyte regeneration and repair. Hyperinsulinaemia and other metabolic factors may also have a direct role in the progression of liver injury. Data indicate that weight reduction improves steatosis and inflammation in patients with chronic hepatitis C. This has important clinical and therapeutic implications and suggests that obesity should be actively addressed in the management of patients with other chronic liver diseases.


Subject(s)
Fatty Liver/complications , Apoptosis , Fatty Liver/metabolism , Fatty Liver/pathology , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/pathology , Hepatocytes/pathology , Humans , Insulin Resistance , Liver Cirrhosis/etiology , Obesity/complications
10.
J Hepatol ; 51(2): 389-97, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19505740

ABSTRACT

BACKGROUND/AIMS: Currently the diagnosis and severity of hepatic steatosis can be established accurately only by liver biopsy. Previous small studies found that steatosis measured by magnetic resonance spectroscopy (MRS) and imaging (MRI) correlated with histological assessment of liver triglyceride content. However, the accuracy of MRS/MRI for grading the severity of steatosis has not been addressed. The aims of this study were (1) to determine whether MRS and MRI can discriminate grades of steatosis in a large cohort of consecutive patients with a wide spectrum of liver disease aetiology and severity (2) to evaluate the effect of hepatic fibrosis, inflammation and iron on quantitation of intrahepatocellular lipid (IHCL) by these techniques. METHODS: Ninety-four sequential patients who underwent percutaneous liver biopsy or liver resection had MRS and MRI (Dixon in phase/out of phase (Dixon IP/OP) and with/without fat saturation (+/-FS) images) to determine IHCL. Histology was used as the reference standard. RESULTS: Close relationships were observed between the percentage of steatosis estimated by histology and MRS/MRI (r(s)=0.88 p<0.001 for all techniques). However, separate equations were required for the percentage of steatosis to avoid underestimation by imaging for patients with moderate or advanced fibrosis. All techniques had good diagnostic accuracy for mild steatosis (AUROC > or =0.87) as well as moderate/severe steatosis (AUROC > or =0.89). Hepatic inflammation and mild iron deposition (Perls' grade 1 and 2) did not interfere with estimation of steatosis by imaging. CONCLUSIONS: MRS and MRI had good accuracy for grading the severity of steatosis in subjects with liver disease, provided that stage of fibrosis was considered.


Subject(s)
Fatty Liver/diagnosis , Fatty Liver/pathology , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Biopsy, Needle , Cell Count , Cohort Studies , Fatty Liver/metabolism , Female , Hepatocytes/pathology , Humans , Iron/metabolism , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Male , Middle Aged , Predictive Value of Tests , ROC Curve , Triglycerides/metabolism
12.
Gastroenterology ; 136(7): 2334-2344.e1, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19303015

ABSTRACT

BACKGROUND & AIMS: The transcription factor nuclear factor-kappaB (NF)-kappaB promotes survival of hepatic myofibroblasts and fibrogenesis through poorly defined mechanisms. We investigated the activities of angiotensin II and I kappaB kinase (IKK) in regulation of NF-kappaB activity and the role of these proteins in liver fibrosis in rodents and humans. METHODS: Phosphorylation of the NF-kappaB subunit RelA at serine 536 (P-Ser(536)-RelA) was detected by immunoblot and immunohistochemical analyses. P-Ser(536)-RelA function was assessed using vectors that expressed mutant forms of RelA, cell-permeable blocking peptides, and assays for RelA nuclear transport and apoptosis. Levels of P-Ser(536)-RelA were compared with degree of fibrosis in liver sections from chronically injured rats and patients with hepatitis C virus-mediated fibrosis who had been treated with the AT1 antagonist losartan. RESULTS: Constitutive P-Ser(536)-RelA is a feature of human hepatic myofibroblasts, both in vitro and in situ in diseased livers. Autocrine angiotensin II stimulated IKK-mediated phosphorylation of RelA at Ser(536), which was required for nuclear transport and transcriptional activity of NF-kappaB. Inhibition of angiotensin II, the angiotensin II receptor type 1 (AT1), or IKK blocked Ser(536) phosphorylation and stimulated myofibroblast apoptosis. Treatment of fibrotic rodent liver with the angiotensin converting enzyme (ACE) inhibitor captopril or the IKK inhibitor sulphasalazine resulted in loss of P-Ser(536)-RelA-positive myofibroblasts and fibrosis regression. In human liver samples, increased numbers of P-Ser(536)-RelA-positive cells were associated with fibrosis that regressed following exposure to losartan. CONCLUSIONS: An autocrine pathway that includes angiotensin II, IKK, and P-Ser(536)-RelA regulates myofibroblast survival and can be targeted to stimulate therapeutic regression of liver fibrosis.


Subject(s)
Angiotensin II/pharmacology , Cell Survival/physiology , Hepatocytes/metabolism , Liver Cirrhosis/pathology , NF-kappa B/metabolism , Transcription Factor RelA/metabolism , Analysis of Variance , Animals , Blotting, Western , Cell Survival/drug effects , Cells, Cultured , Disease Models, Animal , Enzyme Activation/drug effects , Hepatocytes/pathology , Humans , Immunohistochemistry , Liver Cirrhosis/metabolism , Male , Microscopy, Confocal , NF-kappa B/drug effects , Phosphorylation/physiology , Probability , RNA, Transfer, Ser/drug effects , RNA, Transfer, Ser/metabolism , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Signal Transduction/drug effects , Signal Transduction/physiology
13.
14.
J Magn Reson Imaging ; 28(4): 937-45, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18821619

ABSTRACT

PURPOSE: To compare noninvasive MRI and magnetic resonance spectroscopy (MRS) methods with liver biopsy to quantify liver fat content. MATERIALS AND METHODS: Quantification of liver fat was compared by liver biopsy, proton MRS, and MRI using in-phase/out-of-phase (IP/OP) and plus/minus fat saturation (+/-FS) techniques. The reproducibility of each MR measure was also determined. An additional group of overweight patients with steatosis underwent hepatic MRI and MRS before and after a six-month weight-loss program. RESULTS: A close correlation was demonstrated between histological assessment of steatosis and measurement of intrahepatocellular lipid (IHCL) by MRS (r(s) = 0.928, P < 0.0001) and MRI (IP/OP r(s) = 0.942, P < 0.0001; FS r(s) = 0.935, P < 0.0001). Following weight reduction, four of five patients with >5% weight loss had a decrease in IHCL of >or=50%. CONCLUSION: These findings suggest that standard MRI protocols provide a rapid, safe, and quantitative assessment of hepatic steatosis. This is important because MRS is not available on all clinical MRI systems. This will enable noninvasive monitoring of the effects of interventions such as weight loss or pharmacotherapy in patients with fatty liver diseases.


Subject(s)
Fatty Liver/pathology , Magnetic Resonance Imaging/methods , Magnetic Resonance Spectroscopy/methods , Adipose Tissue/pathology , Adult , Biopsy , Fatty Liver/etiology , Fatty Liver/metabolism , Female , Humans , Insulin Resistance , Male , Middle Aged , Obesity/complications , Obesity/metabolism , Obesity/pathology , Reproducibility of Results , Statistics, Nonparametric , Triglycerides/metabolism
15.
J Hepatol ; 49(6): 1046-54, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18752865

ABSTRACT

BACKGROUND/AIMS: Increased expression of sterol regulatory element binding protein (SREBP)-1c, a transcription factor regulating lipogenesis, has been reported in HCV core protein-transfected hepatocytes. Our aim was to investigate the role of SREBP-1c in the pathogenesis of HCV-related steatosis. METHODS: One hundred and twenty-four patients with HCV and 13 subjects with histologically normal liver (NDL) were studied. The mRNA expression of SREBP-1c, fatty acid synthase (FAS), glycerol-3-phosphate acyltransferase (GPAT) and microsomal triglyceride transfer protein (MTP) was measured by qPCR, and SREBP-1 protein quantitated by immunohistochemistry. RESULTS: There was no significant difference in the hepatic expression of SREBP-1c mRNA between subjects with HCV and NDL. In patients with HCV, a significant negative relationship was seen between hepatic SREBP-1c mRNA expression and grade of steatosis (r(s)=-0.28, p=0.002), stage of fibrosis (r(s)=-0.375, p<0.001) and severity of inflammation (r(s)=-0.313, p<0.001). These relationships were observed for patients infected with either viral genotype 1 or 3. Following multivariate logistic regression analysis, hepatic SREBP-1c expression remained independently associated with fibrosis (p=0.008) and hepatic inflammation (p=0.005). HCV-infected patients with HOMA>2 had significantly higher expression of FAS mRNA than HCV-infected subjects with HOMA2 (p=0.006) and NDL (p=0.016). CONCLUSIONS: SREBP-1c may not play a prominent role in the pathogenesis of HCV-related steatosis.


Subject(s)
Fatty Liver , Hepatitis C, Chronic/genetics , Lipogenesis/genetics , Sterol Regulatory Element Binding Protein 1/genetics , Adult , Carrier Proteins/genetics , Fatty Acid Synthases/genetics , Fatty Liver/etiology , Fatty Liver/genetics , Fatty Liver/virology , Female , Gene Expression , Glycerol-3-Phosphate O-Acyltransferase/genetics , Hepatitis C, Chronic/pathology , Humans , Immunohistochemistry , Insulin Resistance/genetics , Male , RNA, Messenger/metabolism , Sterol Regulatory Element Binding Protein 1/metabolism
16.
Mol Diagn Ther ; 12(4): 209-18, 2008.
Article in English | MEDLINE | ID: mdl-18652517

ABSTRACT

Infection with hepatitis C virus (HCV) is a major cause of chronic liver disease. Hepatic fibrosis may develop in subjects with chronic HCV infection, culminating in cirrhosis and an increased risk of hepatocellular carcinoma. The rate of development of fibrosis varies substantially between individuals; while it is influenced by a number of demographic and environmental factors, these account for only a small proportion of the variability. There are no clinical markers or tests that predict the rate of fibrosis progression in an individual subject. Thus, there has been increasing interest in the influence of host genetic factors on the rate of disease progression, and whether a genetic signature can be developed to reliably identify individuals at risk of severe disease. Numerous case-control, candidate gene, allele-association studies have examined the relationship between host single nucleotide polymorphisms or other genetic mutations and fibrosis in patients with chronic HCV infection. However, these studies have generally been irreproducible and disappointing. As seen with genetic studies for other diseases, small study cohorts and poor study design have contributed to limited meaningful findings. The successful determination of genetic signatures for fibrosis progression in chronic HCV will require multicenter collaborations using genome-wide association studies, with large, phenotypically well-defined sample sets. While these studies will require a significant financial commitment, a successful outcome offers the potential for personalized therapy and better patient management.


Subject(s)
Genetic Markers , Hepacivirus/physiology , Hepatitis C/genetics , Polymorphism, Genetic , Disease Progression , Genetic Predisposition to Disease , Hepatitis C/physiopathology , Humans , Liver Cirrhosis/genetics
17.
Hepatology ; 48(1): 80-7, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18571785

ABSTRACT

UNLABELLED: Obesity and fatty liver are commonly observed among patients with chronic hepatitis C virus (HCV) and are risk factors for increased hepatic fibrosis. Obesity is accompanied by a low-grade, chronic inflammatory response that may contribute to pathogenesis of obesity-related comorbidities. To assess whether obesity and steatosis potentiate expression of inflammatory markers in chronic HCV, serum protein and hepatic messenger RNA (mRNA) levels of c-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were measured in 171 patients with chronic HCV. The relationships of body mass index, steatosis, histological features of inflammation and fibrosis with serum and hepatic levels of these factors were determined. In comparison with lean patients, overweight and obese subjects had increased circulating (P < 0.001) and hepatic (P = 0.003) CRP, and there was a significant correlation between serum protein and hepatic CRP mRNA levels (r(s)= 0.51, P < 0.001). Obesity (P = 0.001) and steatosis (P < 0.001) were associated with increased circulating but not hepatic IL-6, and a weak correlation was seen between serum protein and hepatic IL-6 mRNA levels (r(s)= 0.29, P = 0.003). An independent relationship was seen between hepatic TNF-alpha mRNA levels and higher total inflammatory score (P < 0.001) and stage of fibrosis (P = 0.037). Subjects with HCV genotype 3 had lower hepatic TNF-alpha mRNA levels compared with subjects with genotype 1 (P = 0.017), but there was no relationship between serum TNF-alpha protein and hepatic TNF-alpha mRNA levels. CONCLUSION: In patients with chronic HCV, obesity and steatosis are associated with increased expression of selected inflammatory markers; however, circulating levels of IL-6 and TNF-alpha do not reflect hepatic expression. Hepatic TNF-alpha was associated with both increased inflammatory activity and hepatic fibrosis, providing support for the key role of this pro-inflammatory cytokine in liver injury in chronic HCV.


Subject(s)
Biomarkers/blood , Fatty Liver/complications , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/complications , Obesity/complications , Adult , C-Reactive Protein/genetics , C-Reactive Protein/metabolism , Female , Fibrosis , Hepatitis C, Chronic/metabolism , Hepatitis C, Chronic/pathology , Humans , Interleukin-6/blood , Interleukin-6/genetics , Liver/metabolism , Male , RNA, Messenger/metabolism , Tumor Necrosis Factor-alpha/blood , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
18.
Gastroenterology ; 133(1): 80-90, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17631134

ABSTRACT

BACKGROUND & AIMS: Portal fibrosis and linkage is a key feature of progressive disease in nonalcoholic steatohepatitis (NASH), but not simple steatosis. It is underappreciated and poorly understood. Fatty liver has impaired regeneration that induces a secondary replicative pathway using bipotential, periportal, hepatic progenitor cells (HPCs). We propose that activation of this pathway, with increased cell injury in NASH, also induces a periportal ductular reaction (DR) that could produce a profibrogenic stimulus. METHODS: Biopsy specimens from 107 patients with nonalcoholic fatty liver disease and 11 controls were immunostained with cytokeratin-7 to quantify the DR and HPCs, and with p21 to assess hepatocyte replicative arrest. These results were correlated with clinicopathologic variables. RESULTS: Patients with nonalcoholic fatty liver disease had expansion of HPCs, with a strong association between HPCs and the DR (r(s) = 0.582, P < .0001). In those with NASH (n = 69) there was an increased DR compared with simple steatosis, which correlated with the stage of fibrosis (r(s) = 0.510, P < .0001). The DR increased with the grade of NASH activity (r(s) = 0.478, P < .0001), grade of portal inflammation (r(s) = 0.445, P < .0001), and extent of hepatocyte replicative arrest (r(s) = 0.446, P < .0001). Replicative arrest was in turn associated with insulin resistance (r(s) = 0.450, P < .0001) and NASH activity (r(s) = 0.452, P < .0001). By multivariate analysis, the extent of DR (odds ratio [OR] = 17.9, P = .016), hepatocyte ballooning (OR = 8.1, P < .0001), and portal inflammation (OR = 3.3, P = .005) were associated independently with fibrosis. CONCLUSIONS: These findings suggest that an altered replication pathway in active NASH promotes a periportal DR, which in turn may provoke progressive periportal fibrogenesis.


Subject(s)
Fatty Liver/pathology , Fatty Liver/physiopathology , Liver Cirrhosis/pathology , Liver Cirrhosis/physiopathology , Liver Regeneration , Adult , Biliary Tract Diseases/pathology , Biopsy , Cell Division , Disease Progression , Female , Hepatitis/pathology , Hepatitis/physiopathology , Hepatocytes/metabolism , Hepatocytes/pathology , Humans , Insulin Resistance , Liver/pathology , Liver/physiology , Male , Middle Aged , Proto-Oncogene Proteins p21(ras)/metabolism , Stem Cells/physiology
19.
Clin Liver Dis ; 11(1): 173-89, x, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17544978

ABSTRACT

As obesity prevalence rises, there is evidence that fatty liver disease can act synergistically with other chronic liver diseases to aggravate parenchymal injury. This is characterized best in chronic hepatitis C, where steatosis is caused by viral and metabolic effects. There is evidence that steatosis and its metabolic abnormalities also exacerbate other diseases, such as alcoholic liver disease, hemochromatosis, and, possibly, drug-induced liver disease. The pathogenesis seems related to increased susceptibility of steatotic hepatocytes to apoptosis, enhanced oxidative injury, and altered hepatocytic regeneration. Data suggest that active management of obesity may improve liver injury and decrease the progression of fibrosis in patients who have other chronic liver diseases.


Subject(s)
Fatty Liver/complications , Fatty Liver/physiopathology , Hemochromatosis/etiology , Hepatitis C/etiology , Liver Diseases, Alcoholic/etiology , Humans , Obesity/complications , Risk Factors
20.
J Gastroenterol Hepatol ; 22(4): 504-9, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17376041

ABSTRACT

BACKGROUND AND AIMS: Despite the benefits of modest weight reduction for overweight patients with chronic liver disease, long-term maintenance of weight loss is difficult to achieve in clinical practice. The aims of this study were to determine if a nutrition research protocol could be translated into clinical practice and meet the demand for dietetic service, to evaluate the effectiveness and resource implications of intensive lifestyle intervention for weight loss, and to assess the effectiveness of standard dietetic therapy as a treatment option for patients unable to attend the program. METHOD: Using a modified research protocol, an intensive weight reduction program was introduced into standard clinical care for overweight patients attending a tertiary hospital liver outpatient clinic. An audit of weight loss and cost outcomes was conducted. RESULTS: Ninety-three patients were referred to the dietetic service for weight management. Of these, 50 enrolled in an intensive lifestyle intervention, 18 received standard dietetic therapy and 25 refused any intervention. After 6 months, 83% of patients in the intensive intervention achieved weight loss with a significant decrease in weight (P < 0.001) and waist circumference (P < 0.001). In contrast, only 24% of patients receiving standard dietetic therapy achieved weight loss with no significant change in mean weight or waist circumference. Cost per kilogram weight loss after intensive intervention was $AU31 and continuation of lifestyle intervention was calculated to be less than $AU100 per patient per year. CONCLUSIONS: A clinically based, intensive lifestyle intervention is a feasible treatment option for outpatient weight management in overweight patients with chronic liver disease. Providing patients who are unable to participate in intensive programs with standard dietetic therapy is not cost-effective.


Subject(s)
Cognitive Behavioral Therapy , Obesity/diet therapy , Practice Patterns, Physicians' , Adult , Cognitive Behavioral Therapy/economics , Cost-Benefit Analysis , Diet, Reducing/economics , Female , Humans , Life Style , Liver Diseases/diet therapy , Liver Diseases/therapy , Male , Middle Aged , Patient Compliance
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