3-nitrotyrosine and Liver-Cirrhosis

Between 30 and 50% of the cirrhotic patients who do not show symptoms of clinical hepatic encephalopathy (HE) present minimal hepatic encephalopathy (MHE), with mild cognitive impairment. MHE impairs the quality of life, increases the risk of suffering accidents, predicts the appearance of clinical HE, and is associated with shortened lifespan. Early detection of MHE would be very useful. The "gold standard" for MHE diagnosis is the psychometric hepatic encephalopathy score (PHES). However, it is time consuming and needs adjusting for age and educational level. It would be very useful to have some blood biomarker reflecting the presence of MHE in cirrhotic patients. The aim of this work was to identify serum molecules useful as biomarkers for MHE.. We measured in 63 controls, 43 cirrhotic patients without MHE, and 44 patients with MHE, from Hospital Clinico de Valencia, serum levels of different amino acids, cyclic guanosine monophosphate (cGMP), nitrites+nitrates, and 3-nitrotyrosine. We analyzed for each parameter its diagnostic accuracy as an indicator of MHE, as assessed using the PHES.. These studies supported that 3-nitro-tyrosine is a good marker for MHE. To validate its utility as a biomarker for MHE, we analyzed in a second cohort of 44 cirrhotic patients without MHE and 18 patients with MHE, from Hospital Arnau de Vilanova, serum levels of 3-nitro-tyrosine, methionine, and citrulline. Citrulline (173±17%), methionine (173±16%), and 3-nitro-tyrosine (857±92%) were increased in sera from patients with MHE when compared with those without MHE. The receiver operating characteristic (ROC) curve analysis of 3-nitro-tyrosine for the diagnosis of MHE in the first cohort showed an area under the curve (AUC) value of 0.96 (95% confidence interval 0.93-0.99). At the cutoff of 14 nM, the specificity was 93%, sensitivity 89%, and positive and negative predictive values were both 91%. When the same cutoff was applied to the second cohort, the specificity was 83% and sensitivity was 94%. The positive and negative predictive values were 70 and 97%, respectively.. This pilot study, to be validated in a larger cohort, shows that determination of 3-nitro-tyrosine in serum, which is easy and not time consuming, is useful to identify patients with MHE, with good sensitivity, specificity, and positive and negative predictive values.

Topics: Adult; Aged; Area Under Curve; Biomarkers; Citrulline; Early Diagnosis; Hepatic Encephalopathy; Humans; Liver Cirrhosis; Methionine; Middle Aged; Pilot Projects; Predictive Value of Tests; Prospective Studies; Psychometrics; ROC Curve; Tyrosine

Thioacetamide (TAA) administration is widely used for induction of liver cirrhosis in rats, where reactive oxygen radicals (ROS) and nitric oxide (NO) participate in development of liver damage. Cardiac dysfunction is an important complication of liver cirrhosis, but the role of ROS or NO in cardiac abnormalities during liver cirrhosis is not well understood. This was investigated in animals after TAA-induced liver cirrhosis and temporal changes in oxidative stress, NO and mitochondrial function in the heart evaluated. TAA induced elevation in cardiac levels of nitrate before development of frank liver cirrhosis, without gross histological alterations. This was accompanied by an early induction of P38 MAP kinase, which is influenced by ROS and plays an important signaling role for induction of iNOS. Increased nitrotyrosine, protein oxidation and lipid peroxidation in the heart and cardiac mitochondria, suggestive of oxidative stress, also preceded frank liver cirrhosis. However, compromised cardiac mitochondrial function with a decrease in respiratory control ratio and increased mitochondrial swelling was seen later, when cirrhosis was evident. In conclusion, TAA induces elevations in ROS and NO in the heart in parallel to early liver damage. This leads to later development of functional deficits in cardiac mitochondria after development of liver cirrhosis.

Topics: Animals; Chemical and Drug Induced Liver Injury; Female; Heart Diseases; Lipid Peroxidation; Liver; Liver Cirrhosis; Male; Mitochondria, Heart; Mitochondrial Swelling; Myocytes, Cardiac; Nitrates; Nitric Oxide; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Rats, Wistar; Reactive Oxygen Species; Signal Transduction; Thioacetamide; Time Factors; Tyrosine

Genistein is a major isoflavonoid abundantly found in soy. Earlier genistein has been reported to possess protective effect against a multitude of disorders including cancer. Previously we demonstrated the protective effects of Genistein in d-Galactosamine (D-GalN) induced fulminant hepatic failure (FHF) in rats. In present study, we evaluated the hepatoprotective activity of Genistein in rat model of chronic liver damage and liver fibrosis.. Liver fibrosis was induced by intraperitoneal injection of D-GalN (250 mg/kg BW) twice a week for 12 weeks. Genistein (5 mg/kg BW) was given via intra-gastric route as co-treatment daily for 12 weeks.. Genistein co-treatment significantly attenuated D-GalN-induced chronic liver damage and liver fibrosis as evident from a significant amelioration in functional impairment, including inhibition of the activation of Hepatic stellate cells (HSC), decreased expression in alpha smooth muscle actin (α-SMA) and accumulation of collagen matrix, and an elevation in serum alanine transaminase (ALT) and aspartate transaminase (AST) level. In addition Genistein co-treatment was associated with elevated expression of hepatic Smad7, which ultimately blunts the expression of TGF-β and the activation of TGF-β/Smad signaling. Furthermore Genistein significantly prevented the histopathological changes induced by D-GalN.. Our results suggest that Genistein could be a novel therapeutic/nutraceutical agent in treating chronic liver damage and liver fibrosis. In addition our study also suggests a possible mechanism of action in which Smad7-induced inhibition of TGF-β/Smad2/3 can be a central mechanism by which Genistein protects liver from chronic injury.

Topics: Animals; Blotting, Western; Chronic Disease; Collagen; Galactosamine; Genistein; Hepatic Stellate Cells; In Situ Nick-End Labeling; Liver; Liver Cirrhosis; Male; Rats, Wistar; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Tyrosine

A new, precise, and very selective method for increasing the impact and assessment of 3-nitrotyrosine (3-Nty) as a biomarker for early diagnosis of liver cirrhosis with minimal hepatic encephalopathy (MHE) disease was developed. The method depends on the formation of the ion pair associate between 3-nitrotyrosine and the optical sensor binuclear Pt-2-pyrazinecarboxylic acid (pca)-Bipyridine (bpy) complex doped in sol-gel matrix in buffer solution of pH 7.3. The binuclear Pt (pca)(bpy) has +II net charge which is very selective and sensitive for [3-Nty](-2) at pH 7.3 in serum sample of liver cirrhosis with MHE diseases. 3-nitrotyrosine (3-Nty) quenches the luminescence intensity of the nano optical sensor binuclear Pt(pca) (bpy) at 528nm after excitation at 370nm, pH 7.3. The remarkable quenching of the luminescence intensity at 528nm of nano binuclear Pt(pca) (bpy) doped in sol-gel matrix by various concentrations of the 3-Nty was successfully used as an optical sensor for the assessment of 3-Nty in different serum samples of (MHE) in patients with liver cirrhosis. The calibration plot was achieved over the concentration range 1.85×10(-5) - 7.95×10(-10)molL(-1) 3-Nty with a correlation coefficient of (0.999) and a detection limit of (4.7×10(-10)molL(-1)). The method increases the sensitivity (93.75%) and specificity (96.45%) of 3-Nty as a biomarker for early diagnosis of liver cirrhosis with MHE in patients.

Topics: Adult; Biomarkers; Early Diagnosis; Equipment Design; Equipment Failure Analysis; Female; Hepatic Encephalopathy; Humans; Liver Cirrhosis; Luminescent Measurements; Male; Middle Aged; Optical Devices; Platinum; Pyrazinamide; Reproducibility of Results; Sensitivity and Specificity; Transducers; Tyrosine

Liver fibrosis and cirrhosis are leading causes of morbidity and mortality, with majority of preventable cases attributed to excessive alcohol consumption, viral hepatitis, or non-alcoholic fatty liver disease. We previously reported the hepatoprotective effect of Glycine propionyl-l-carnitine (GPLC) against the fulminant hepatic failure (FHF) induced by d-Galactosamine (D-GalN). In this study we evaluated the protective effect of GPLC against D-GalN induced chronic liver damage.. Animals received D-GalN twice a week for 12 weeks at a dose of 250 mg/kg body weight (BW). GPLC was given daily for 12 weeks as co-treatment along with D-GalN at a dose of 35 mg/kg BW.. D-GalN injection resulted in a considerable decrease in body weight, hepatocellular disintegration, necrosis and lipid peroxidation as evident from altered levels of SOD, CAT and MDA while GPLC significantly restored the reduced body weight and ameliorated hepatocellular damage and lipid peroxidation. D-GalN administration resulted in DNA damage as evident from TUNEL positive cells in disease control rats while; GPLC significantly alleviated the genotoxic effects of D-GalN. Further histopathological analysis revealed significant tissue and cellular damage, and increased collagen content in D-GalN challenged rats. GPLC however ameliorated the damage as evident from normal cellular and morphological architecture in GPLC co-treated rats. Hydroxyproline and nitrotyrosine (NTY) levels marked a significant decrease in GPLC co-treated rats relative to disease control. GPLC significantly blocked D-GalN induced pro-inflammatory cytokine (TNF-α, IL-6) production and at the same time inhibited the expression of α-smooth muscle actin (α-SMA), collagen-I (COL-I) and transforming growth factor-β (TGF-β) significantly.. Our results demonstrate significant protective activity of GPLC in chronic liver damage and other complications related to it. This study is a novel study to demonstrate the hepatoprotective effect of GPLC in chronic liver damage.

Topics: Actins; Animals; Body Weight; Carnitine; Chronic Disease; Collagen Type I; Galactosamine; Gene Expression Regulation; Glycine; Hydroxyproline; In Situ Nick-End Labeling; Interleukin-6; Liver; Liver Cirrhosis; Male; Oxidative Stress; Rats, Wistar; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Tyrosine

Cirrhotic patients with minimal hepatic encephalopathy (MHE) show impaired driving ability and increased vehicle accidents. The neurological deficits contributing to impair driving and the underlying mechanisms are poorly understood. Early detection of driving impairment would help to reduce traffic accidents in MHE patients. It would be therefore useful to have psychometric or biochemical parameters reflecting driving impairment. The aims of this work were as follows: (i) to shed light on the neurological deficits contributing to impair driving; (ii) to assess whether some psychometric test or biochemical parameter is a good indicator of driving impairment.. We assessed in 22 controls, 36 cirrhotic patients without and 15 with MHE, driving performance using a driving simulator (SIMUVEG) and Driver Test. MHE was diagnosed using the psychometric hepatic encephalopathy score (PHES). Psychometric tests assessing different neurological functions (mental processing speed, attention, visuo-spatial and bimanual coordination) were performed. Blood ammonia and parameters related with nitric oxide-cGMP metabolism, IL-6, IL-18 and 3-nitrotyrosine were measured.. Patients with MHE showed impaired driving ability correlating with MHE grade, with impaired vehicle lateral control in spite of reduced driving speed. Patients with MHE show psychomotor slowing, longer reaction times, impaired bimanual and visuo-spatial coordination and concentrated attention and slowed speed of anticipation and increased blood ammonia, cGMP, IL-6, IL-18 and 3-nitrotyrosine.. Impaired mental processing speed, attention and alterations in visuo-spatial and motor coordination seem main contributors to impaired driving ability in patients with MHE. Increased serum 3-nitrotyrosine is associated with impaired driving ability.

Topics: Adult; Aged; Analysis of Variance; Automobile Driving; Biomarkers; Chemokines; Cyclic GMP; Flicker Fusion; Hepatic Encephalopathy; Humans; Liver Cirrhosis; Middle Aged; Nitric Oxide; Psychometrics; Tyrosine

To investigate whether "binge" and escalating alcohol exposure in the rat influences the development of pathological liver injury.. Time courses for the formation of eicosanoids by cyclooxygenase (COX), oxidative stress and nitrosative stress production, expression of hypoxia-inducible factor 1 (HIF-1), cytokines, hepatic tissue necroinflammation, and fibrosis were assessed in rats during 16 weeks of daily alcohol gavage.. In this model of binge and escalating levels of alcohol, hepatic steatosis, necrosis, and inflammation as well as fibrosis were increased over the 16-week period. The levels of COX-2, oxidative stress, nitrosative stress, HIF-1, proinflammatory mediators (tumor necrosis factor-α, interleukin 1(β) [IL-1(β) ], IL-6), and procollagen-I were increased over the 16-week period. The content of IL-10 in rat serum increased at the end of 4 and 8 weeks but decreased thereafter and was significantly decreased at 12 and 16 weeks.. A rat model of alcoholic liver disease (ALD) with long-term binge and escalating ethanol exposure was developed. Our data support the hypothesis that enhanced eicosanoid production by COX, oxidative stress and nitrosative stress, HIF-1, and the imbalance between pro- and anti-inflammatory cytokines plays an important role in the pathogenesis of ALD.

Topics: Animals; Binge Drinking; Cyclooxygenase 1; Cyclooxygenase 2; Cytokines; Ethanol; Hypoxia-Inducible Factor 1; Inflammation; Inflammation Mediators; Liver; Liver Cirrhosis; Male; Necrosis; Nitric Oxide Synthase Type II; Oxidative Stress; Procollagen; Rats; Rats, Wistar; Tyrosine

Hyperammonemia and sarcopenia (loss of skeletal muscle) are consistent abnormalities in cirrhosis and portosystemic shunting. We have shown that muscle ubiquitin-proteasome components are not increased with hyperammonemia despite sarcopenia. This suggests that an alternative mechanism of proteolysis contributes to sarcopenia in cirrhosis. We hypothesized that autophagy could be this alternative pathway since we observed increases in classic autophagy markers, increased LC3 lipidation, beclin-1 expression, and p62 degradation in immunoblots of skeletal muscle protein in cirrhotic patients. We observed similar changes in these autophagy markers in the portacaval anastamosis (PCA) rat model. To determine the mechanistic relationship between hyperammonemia and autophagy, we exposed murine C(2)C(12) myotubes to ammonium acetate. Significant increases in LC3 lipidation, beclin-1 expression, and p62 degradation occurred by 1 h, whereas autophagy gene expression (LC3, Atg5, Atg7, beclin-1) increased at 24 h. C(2)C(12) cells stably expressing GFP-LC3 or GFP-mCherry-LC3 constructs showed increased formation of mature autophagosomes supported by electron microscopic studies. Hyperammonemia also increased autophagic flux in mice, as quantified by an in vivo autophagometer. Because hyperammonemia induces nitration of proteins in astrocytes, we quantified global muscle protein nitration in cirrhotic patients, in the PCA rat, and in C(2)C(12) cells treated with ammonium acetate. Increased protein nitration was observed in all of these systems. Furthermore, colocalization of nitrated proteins with GFP-LC3-positive puncta in hyperammonemic C(2)C(12) cells suggested that autophagy is involved in degradation of nitrated proteins. These observations show that increased skeletal muscle autophagy in cirrhosis is mediated by hyperammonemia and may contribute to sarcopenia of cirrhosis.

Topics: Animals; Autophagy; Cell Line; Cells, Cultured; Fluorescent Antibody Technique; Humans; Hydrogen-Ion Concentration; Hyperammonemia; Liver Cirrhosis; Male; Mice; Microscopy, Confocal; Microscopy, Electron; Microtubule-Associated Proteins; Muscle Proteins; Muscle, Skeletal; Portacaval Shunt, Surgical; Proteasome Endopeptidase Complex; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; RNA; Sarcopenia; Transfection; Tyrosine

The anti-inflammatory and antioxidant effects of epigallocatechin-3-gallate (EGCG) are considered important forces in attenuate liver injury and fibrosis. The aim of the study was to investigate the effect of EGCG on the expression of fibrogenic factors and whether EGCG attenuates the severity of oxidative stress and inflammatory response in chronic liver injury. Mice were administered with CCl(4) together with or without EGCG for 8 weeks (n=6-8 per group). Histopathological and biochemical analyses were carried out. The mRNA expression levels of TNF-alpha, COX-2, iNOS, alpha-smooth muscle actin (alpha-SMA), transforming growth factor (TGF-beta(1)), pro-collagen-I, matrix metalloproteinases (MMP-2, -9) and their inhibitors (TIMP-1, -2) were determined by RT-PCR. The collagen deposited in the liver was detected by Sirius Red staining. The formation of nitrotyrosine was measured as a marker of oxidative stress. The activity level of NF-kappaB and the expression level of C/EBP were also assessed. Chronic CCl(4) treatment caused liver injury, oxidative stress and nitrosative stress, and collagen accumulation in the liver. The expression levels of pro-inflammatory and pro-fibrotic mediators and the activity of NF-kappaB were increased. Treatment with EGCG significantly reduced liver injury, oxidative stress and the inflammatory response. EGCG also significantly reduced the formation of collagen in the liver, the expression of alpha-SMA and all of the assayed pro-fibrogenic markers except TIMP-2 and MMP-9. EGCG significantly attenuated the severity of CCl(4)-induced liver injury and the progression of liver fibrosis. The protective effect of EGCG may in part be a consequence of the reduction in oxidative stress and the pro-inflammatory response.

Topics: Actins; Animals; Anti-Inflammatory Agents; Carbon Tetrachloride; Catechin; Chemical and Drug Induced Liver Injury; Collagen Type I; Cyclooxygenase 2 Inhibitors; Liver Cirrhosis; Male; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II; Oxidative Stress; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha; Tyrosine

Portal hypertensive (PHT) gastric mucosa increases susceptibility to injury and delayed mucosal healing. It is possible that nitration of ERK by peroxynitrite might alter MAPK (ERK) signaling in PHT gastric mucosa, leading to delayed mucosal healing, since excessive nitric oxide production is implicated in PHT gastric mucosa and MAPK (ERK) signaling induces cell proliferation and leads to gastric mucosal healing in response to injury. Portal hypertension was produced by staged portal vein ligation, and sham-operation (SO) rats served as controls. Lipid peroxide (LPO) and nitrotyrosine increased significantly in PHT gastric mucosa compared with SO rats. ERK activation was impaired in PHT gastric mucosa in response to ethanol injury, whereas no significant difference in the phosphorylation of MEK, an upstream molecule of ERK, was seen between the two groups. The nitration of ERK by peroxynitrite, as detected by the coimmunoprecipitation of ERK and nitrotyrosine, was significantly enhanced in PHT gastric mucosa. Administration of rebamipide, a gastroprotective drug that acts as an oxygen-derived free radical scavenger, significantly decreased LPO and nitrotyrosine as well as the nitration of ERK by peroxynitrite in PHT gastric mucosa, therefore normalizing ERK activation and restoring the gastric mucosal healing response to ethanol injury. Enhanced nitration of ERK by peroxynitrite is involved in the impaired MAPK (ERK) signaling in PHT gastric mucosa. These findings demonstrate a new molecular mechanism in which PHT gastric mucosa is predisposed to injury and impaired healing.

Topics: Alanine; Animals; Enzyme Inhibitors; Ethanol; Extracellular Signal-Regulated MAP Kinases; Gastric Mucosa; Liver Cirrhosis; MAP Kinase Kinase Kinases; Nitrates; Oxidative Stress; Peroxynitrous Acid; Quinolones; Rats; Rats, Sprague-Dawley; Signal Transduction; Stomach Diseases; Tyrosine

Intrahepatic cholangiocarcinoma (CCA) is a lethal malignancy of the biliary epithelium associated with p53 mutations, bile duct injury, inflammation, and fibrosis. Here, to validate these processes in CCA, we developed a liver cirrhosis model driven by chronic intermittent toxin exposure, which provokes bile duct injury/necrosis and proliferation, fibroblast recruitment, and progressive extracellular matrix (ECM) changes. Fibrotic changes in the matrix microenvironment, typified by increased type I and III collagens and fibroblast recruitment, were shown to stimulate biliary epithelium hyperplasia with subsequent progression to malignant intrahepatic CCA only in mice harboring a p53 mutant allele. These murine CCAs bear histologic and genetic features of human intrahepatic CCA, including dense peritumoral fibrosis, increased inducible nitric oxide synthase, nitrotyrosine, and cyclooxygenase-2 expression, c-Met activation, cErbB2 overexpression, down-regulation of membrane-associated E-cadherin, and p53 codon 248 mutation. Thus, p53 deficiency, chronic bile duct injury/proliferation, and the fibrotic matrix microenvironment cooperate to induce intrahepatic CCA, highlighting the key role of the ECM microenvironment in this common liver cancer.

Topics: Animals; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Cadherins; Carbon Tetrachloride Poisoning; Cholangiocarcinoma; Cyclooxygenase 2; Extracellular Matrix; Female; Fibrosis; Germ-Line Mutation; Hyperplasia; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II; Proto-Oncogene Proteins c-met; Receptor, ErbB-2; Tumor Suppressor Protein p53; Tyrosine

Plasma S-nitrosothiols are believed to function as a circulating form of nitric oxide that affects both vascular function and platelet aggregation. However, the formation of circulating S-nitrosothiols in relation to acute and chronic disease is largely unknown. Plasma S-nitrosothiols were measured by chemiluminescence in rats with biliary cirrhosis or controls, and the effect of lipopolysaccharide (LPS) on their formation was determined. Plasma S-nitrosothiols were increased in rats with cirrhosis (206 +/- 59 nM) compared to controls (51 +/- 6 nM, p <.001). Two hours following injection of LPS (0.5 mg/kg) plasma S-nitrosothiols increased to 108 +/- 23 nM in controls (p <.01) and to 1335 +/- 423 nM in cirrhotic rats (p <.001). The plasma clearance and half-life of S-nitrosoalbumin, the predominant circulating S-nitrosothiol, were similar in control and cirrhotic rats, confirming that the increased plasma concentrations were due to increased synthesis. Because reactive nitrogen species, such as peroxynitrite, may cause the formation of S-nitrosothiols in vivo, we determined the levels of nitrotyrosine by gas chromatography/mass spectrometry as an index for these nitrating and nitrosating radicals. Hepatic nitrotyrosine levels were increased at 7.0 +/- 1.2 ng/mg in cirrhotic rats compared to controls (2.0 +/- 0.2 ng/mg, p <.01). Hepatic nitrotyrosine levels increased by 2.3-fold and 1.5-fold in control and cirrhotic rats, respectively, at 2 h following injection of LPS (p <.01). Strong positive staining for nitrotyrosine was shown by immunohistochemistry in all the livers of the rats with cirrhosis. We conclude that there is increased formation of S-nitrosothiols and nitrotyrosine in biliary cirrhosis, and this is markedly upregulated during endotoxemia.

Topics: Animals; Endotoxemia; Gas Chromatography-Mass Spectrometry; Half-Life; Immunohistochemistry; Lipopolysaccharides; Liver; Liver Cirrhosis; Luminescent Measurements; Male; Metabolic Clearance Rate; Neutrophils; Nitroso Compounds; Rats; Rats, Sprague-Dawley; S-Nitrosothiols; Serum Albumin, Bovine; Tyrosine

We investigated the potential of arginine to reverse pathological changes in alcohol-induced liver injury. Four groups (six rats/group) of male Wistar rats were fed a fish oil-ethanol diet for 6 (group 2) or 8 (group 1) weeks. Rats in group 3 were fed fish oil-ethanol for 6 weeks, after which they were administered arginine with fish oil-ethanol for an additional 2 weeks. Rats in group 4 were fed fish oil-dextrose for 8 weeks. Liver samples were analyzed for histopathology, lipid peroxidation, cytochrome P4502E1 activity, nuclear factor-kappaB, and levels of messenger RNA for tumor necrosis factor-alpha, cyclooxygenase-2, and inducible nitric oxide synthase. Concentrations of endotoxin were measured in plasma. The most severe inflammation and fibrosis was detected in groups 1 and 2, as were the highest levels of endotoxin, lipid peroxidation, cytochrome P450 2E1 activity, activation of nuclear factor-kappaB, and mRNA levels for tumor necrosis factor-alpha, cyclooxygenase-2, and inducible nitric oxide synthase. Plasma nitric oxide was also increased as was nitrotyrosine in liver. After arginine was administered, there was marked improvement in the pathological changes accompanied by decreased levels of endotoxin, lipid peroxidation, activation of nuclear factor-kappaB, tumor necrosis factor-alpha, cyclooxygenase-2, inducible nitric oxide, and nitrotyrosine staining. The therapeutic effects of arginine are probably secondary to increased levels of nitric oxide but other effects of arginine cannot be excluded.

Topics: Animals; Arginine; Cyclooxygenase 2; Disease Models, Animal; Down-Regulation; Drug Interactions; Endotoxins; Ethanol; Humans; Inflammation; Isoenzymes; Lipid Peroxidation; Liver; Liver Cirrhosis; Liver Cirrhosis, Alcoholic; Male; Membrane Proteins; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha; Tyrosine

Nonalcoholic steatohepatitis is an emerging clinical problem among the obese population. However, risk factors of progression to advanced forms of liver disease in this particular group of patients remain to be defined.. The demographics and clinical and histologic features of 46 obese patients were evaluated. The intrahepatic immunological phenotype was assessed in all liver biopsy samples by immunohistochemistry.. Histologic findings of nonalcoholic steatohepatitis were observed in 69.5% of the obese population studied and significant fibrosis was evident in 41% of patients with nonalcoholic steatohepatitis. Age (p=0.003), degree of steatosis (p=0.000002), and grade of inflammation (p=0000) at liver biopsy were independent variables positively associated with fibrosis. Intrahepatic expression levels of several immunologic markers of inflammation as well as nitric oxide derivatives were significantly higher in the severe forms of nonalcoholic steatohepatitis than in the mildest forms.. Obese persons with higher age, with greater degrees of hepatic steatosis, and specially those with increased grades of intrahepatic inflammation have the greatest risk for progression to fibrotic liver disease. An oxidative stress-triggered intrahepatic inflammatory response appears to be important in the pathogenesis of nonalcoholic steatohepatitis in obesity.

Topics: Adult; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; Endoglin; Female; Hepatitis; Humans; Immunohistochemistry; Intercellular Adhesion Molecule-1; Lectins, C-Type; Liver; Liver Cirrhosis; Male; Middle Aged; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Obesity; Prognosis; Receptors, Cell Surface; Tyrosine; Vascular Cell Adhesion Molecule-1

During inflammation nitric oxide reacts at near diffusion limited rates with superoxide to form the strong oxidant peroxynitrite. Nitration on the ortho position is a major product of peroxynitrite attack on proteins. In the present study we investigated whether immunohistochemical detection of nitrotyrosine (footprint of peroxynitrite) can be associated with human hepatitis. Paraffin-embedded liver tissue biopsies from patients with chronic active hepatitis, chronic active hepatitis plus cirrhosis and chronic persistent hepatitis exhibit significant specific immunostaining with the antibody to nitrotyrosine. Positive staining was found in 57% and 72% of tissue specimens from patients with chronic hepatitis and cirrhosis, respectively. Immunohistochemical staining of nitrotyrosine residues was found in the hepatocytes and Kuppffer cells of the necrotic area. The presence of nitrotyrosine indicates that oxidants derived from nitric oxide such as peroxynitrite are generated in human hepatitis and may be involved in its pathogenesis.

Topics: Adult; Antibodies; Antibody Specificity; Female; Hepatitis B, Chronic; Hepatitis C, Chronic; Humans; Immunohistochemistry; Liver Cirrhosis; Male; Middle Aged; Nitrates; Tyrosine