bromochloroacetic-acid and Liver-Diseases--Alcoholic

Mallory bodies (MBs) are characteristic morphologic features of alcoholic hepatitis but are also associated with non-alcoholic liver diseases including long lasting cholestasis, metabolic and neoplastic disorders. MBs contain in addition to keratins non-keratin components, including microtubule-associated (tau protein) and other not yet characterized proteins in an aggregated form. Aggregation of these components in the cell is promoted by posttranslational modifications, such as partial proteolysis, phosphorylation and cross-linking, and may result in functional and structural disturbances of the cell depending on the physiologic function of the components involved. Several enzymes responsible for these modifications are Ca(++)-dependent. Thus, disturbance of Ca(++)-homeostasis may play an essential role in the pathogenesis of MBs. In some structural aspects MBs closely resemble inclusions associated with degenerative disorders of the central nervous system, including Alzheimer's and Parkinson's disease. Studies on the pathogenesis of MBs, therefore, not only shed light on a peculiar type of liver cell injury but may also assist in the understanding of other chronic degenerative diseases, particularly those of the central nervous system.

Topics: Alzheimer Disease; Animals; Brain Diseases; Calcium; Homeostasis; Humans; Keratins; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases; Liver Diseases, Alcoholic; Parkinson Disease; Protein Processing, Post-Translational; Transcription, Genetic

Mallory-Denk bodies (MDBs) form in the liver of alcoholic patients. This occurs because of the accumulation and aggregation of ubiquitinated cytokeratins, which hypothetically is due to the ubiquitin-proteasome pathway's (UPP) failure to degrade the cytokeratins. The experimental model of MDB formation was used in which MDBs were induced by refeeding DDC to drug-primed mice. The gene expression and protein levels of LMP2, LMP7 and MECL-1, the catalytic subunits in the immunoproteasome, as well as FAT10, were increased in the liver cells forming MDBs but not in the intervening normal hepatocytes. Chymotrypsin-like activity of the UPP was decreased by DDC refeeding, indicating that a switch from the UPP to the immunoproteasome had occurred at the expense of the 26S proteasome. The failure of the UPP to digest cytokeratins would explain MDB aggregate formation. SAMe prevented the decrease in UPP activity, the increase in LMP2, LMP7, and MECL-1 protein levels and MDB formation induced by DDC. DDC refeeding also induced the TNFalpha and IFNgamma receptors. SAMe prevented the increase in the TNFalpha and IFNgamma receptors, supporting the idea that TNFalpha and IFNgamma were responsible for the up regulation of LMP2, LPM7, and FAT10. These results support the conclusion that MDBs form in FAT10 over-expressing hepatocytes where the up regulation of the immunoproteasome occurs at the expense of the 26S proteasome.

Topics: Animals; Base Sequence; Cysteine Endopeptidases; Dihydropyridines; Disease Models, Animal; DNA Primers; Gene Expression; Inclusion Bodies; Keratins; Liver; Liver Diseases, Alcoholic; Male; Mice; Mice, Inbred C3H; Multienzyme Complexes; Proteasome Endopeptidase Complex; S-Adenosylmethionine; Ubiquitin; Ubiquitins

Serum cytokeratin (CK) levels are widely used as tumor markers. Serum levels of CK-18, a tumor marker also known as tissue polypeptide specific antigen (TPS), are increased in patients with alcoholic liver disease. Cytokeratin-18 is the main component of Mallory bodies, a hallmark of alcoholic hepatitis, which may also contain CK-19. Serum levels of CK-18 and CK-19, a tumor marker also known as CYtokeratin FRAgment 21-1 (CYFRA 21-1) were investigated in (a) heavy drinkers with alcoholic liver disease (n=15), (b) patients with malignancy (n=22), and (c) healthy controls (n=10). Serum levels of CYFRA 21-1 (CK-19) were markedly increased in patients with malignancy, but were similar in heavy drinkers and healthy controls. In contrast, serum levels of TPS (CK-18) in heavy drinkers were higher than those of healthy controls, and even tended to be higher than those of patients with malignancy. Both CK-19 and CK-18 levels were higher in cases of alcoholic hepatitis than in cases of fatty liver. Correlation with hepatocyte CK inclusions was stronger for serum TPS (CK-18) than for CYFRA 21-1 (CK-19). In conclusion, serum CYFRA 21-1 (CK-19) and TPS (CK-18) show a different pattern of increase that could reflect the composition of the altered hepatocyte CK network in alcoholic liver disease. Their usefulness as tumor markers, particularly that of serum TPS (CK-18), may be limited in patients with alcoholic liver disease.

Topics: Adult; Alcohol Drinking; Female; Humans; Keratins; Liver Diseases, Alcoholic; Male; Middle Aged

Misfolded and aggregated proteins are a characteristic feature of a variety of chronic diseases. Examples include neurofibrillary tangles in Alzheimer disease, Lewy bodies in Parkinson disease and Mallory bodies (MBs) in chronic liver diseases, particularly alcoholic and non-alcoholic steatohepatitis (ASH and NASH). MB formation is at least in part the result of chronic oxidative cell stress in hepatocytes and can be induced in mice by long-term intoxication with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). Proteomic analysis revealed that MBs consist of ubiquitinated keratins and the stress proteins Hsp70, Hsp25, and p62. Furthermore, marked overexpression of clusterin, which shares functional properties with small heat shock proteins, was identified by gene expression profiling of DDC-treated mice livers. To investigate whether clusterin has a function in the stress response to misfolded keratins, we performed transfection studies utilizing expression constructs encoding ubiquitin, p62, Hsp27, clusterin, keratin 8, and keratin 18. Ubiquitin was found in a strong and constant association with keratin aggregates, whereas binding of p62 to keratin was variable. Hsp27 did not colocalize with keratin aggregates under these experimental conditions. In contrast, clusterin associated with misfolded keratin only if its signal peptide was deleted and its secretion inhibited. This suggests that clusterin has ability to bind misfolded proteins, including keratins but its physiological function is restricted to the extracellular space. The extracellular localization of clusterin was underlined by immunohistochemical studies in Alzheimer disease brains, where clusterin was constantly found in association with amyloid plaques; in contrast, cytoplasmic inclusions such as neurofibrillary tangles as well as MBs in ASH were negative. Furthermore, we found clusterin in association with elastic fibers in the extracellular matrix in several chronic liver diseases, including ASH and alpha1-antitrypsin deficiency, implying a possible role of clusterin in liver fibrosis.

Topics: Adaptor Proteins, Signal Transducing; Alzheimer Disease; Animals; CHO Cells; Clusterin; Cricetinae; Cricetulus; Glycoproteins; Heat-Shock Proteins; HSP27 Heat-Shock Proteins; Humans; Immunohistochemistry; Keratins; Liver Diseases, Alcoholic; Mice; Molecular Chaperones; Neoplasm Proteins; Protein Folding; Sequestosome-1 Protein; Ubiquitin

Chronic ethanol ingestion leads to inhibition of proteasomal activity. As a consequence, proteins accumulate in liver cells. Cytokeratin accumulation as seen in alcoholic hepatitis could lead to the formation of Mallory bodies. In order to study the phenomenon of cytokeratin accumulation in liver cells, rats were fed ethanol or dextrose for 1 month and some were given the proteasome inhibitor, PS-341, to augment the inhibitory effect of ethanol feeding. This was done to study the involvement of proteasome inhibition in the process of cytokeratin accumulation. There was a marked increase in the accumulation of polyubiquitinated proteins, and heat shock proteins (hsp) 25 and 70 in the liver of rats treated with PS-341. Similarly, cytokeratin-8 (CK-8) levels were markedly increased in the liver homogenates of rats fed ethanol when given PS-341. When normal mouse cultured hepatocytes were transfected with cytokeratin-18 (CK-18) tagged with red fluorescent protein (RFP), CK-18 aggresomes formed because proteasome was overloaded. These data provide new evidence that proteasome inhibition is involved in cytokeratin accumulation, when aggresomes are formed in tissue culture. Accumulation of cytokeratin in this way may ultimately lead to Mallory body formation as seen in alcoholic hepatitis.

Topics: Alcoholism; Animals; Blotting, Western; Boronic Acids; Bortezomib; Cells, Cultured; Cysteine Endopeptidases; Heat-Shock Proteins; Hepatocytes; Keratins; Liver; Liver Diseases, Alcoholic; Male; Mice; Multienzyme Complexes; Protease Inhibitors; Proteasome Endopeptidase Complex; Pyrazines; Rats

Serum levels of the tumor marker tissue polypeptide specific antigen (TPS, cytokeratin 18 fragments) are increased in patients with alcoholic liver disease, particularly in cases of alcoholic hepatitis. Mallory bodies, characteristic of alcoholic hepatitis, are cytokeratin 8 and 18 aggregates. The study was aimed at investigating the possible relationship of serum TPS levels with hepatocyte cytokeratin expression in patients with alcoholic liver disease.. Twenty-four patients with alcoholic liver disease were studied. Immunohistochemical staining for cytokeratins 8 and 18 was performed in liver specimens by means of CAM 5.2 monoclonal antibody. The number of hepatocytes containing CAM 5.2-reactive cytokeratin inclusions was compared with serum TPS levels.. The vast majority of alcoholics (95%) showed increased (>100 units/liter) serum TPS levels. Serum TPS levels were significantly correlated with the number of hepatocyte cytokeratin inclusions. Serum TPS levels can predict hepatocyte cytokeratin expression in patients with alcoholic liver disease.

Topics: Adult; Female; Hepatocytes; Humans; Keratins; Linear Models; Liver Diseases, Alcoholic; Male; Middle Aged; Peptides; Statistics, Nonparametric

The risk of developing hepatocellular carcinoma is significantly increased in patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C infection. The precise mechanisms underlying the development of hepatocellular carcinoma in these conditions are not well understood. Stem cells within the liver, termed oval cells, are involved in the pathogenesis of hepatocellular carcinoma in animal models and may be important in the development of hepatocellular carcinoma in human chronic liver diseases. The aims of this study were to determine whether oval cells could be detected in the liver of patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C, and whether there is a relationship between the severity of the liver disease and the number of oval cells. Oval cells were detected using histology and immunohistochemistry in liver biopsies from patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. Oval cells were not observed in normal liver controls. Oval cell numbers increased significantly with the progression of disease severity from mild to severe in each of the diseases studied. We conclude that oval cells are frequently found in subjects with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. There is an association between severity of liver disease and increase in the number of oval cells consistent with the hypothesis that oval cell proliferation is associated with increased risk for development of hepatocellular carcinoma in chronic liver disease.

Topics: Cell Count; Disease Progression; Glutathione Transferase; Hemochromatosis; Hepatitis C, Chronic; Humans; Immunoenzyme Techniques; Keratins; Leukocyte Common Antigens; Liver; Liver Diseases, Alcoholic; Pyruvate Kinase; Stem Cells

Mallory bodies (MBs) are eosinophilic cytoplasmic inclusions observed predominantly in alcoholic liver disease. Although linked to disease activity, their pathogenesis is still unclear. Since intermediate filaments (cytokeratins) are major components of MBs, their cytokeratin polypeptide composition was analysed with monospecific antibodies for cytokeratins 7, 8, 14, 18, 19, and 20 by immunohistology. MBs were identified by light microscopy and ubiquitin immunostaining. All MBs were positive for cytokeratins 8 and 18. A significant percentage of the MBs was strongly positive for cytokeratins 19 and/or 20, which are not detectable in hepatocytes of normal liver and, in the case of cytokeratin 20, in hepatocytes of diseases devoid of MBs. MBs were essentially negative for cytokeratins 7 and 14. De novo expression of cytokeratins 19 and 20 was independent of the aetiology, occurring in all MB-associated diseases analysed, and seemed to precede MB formation, since in some hepatocytes a cytoskeletal-type staining pattern for these cytokeratins was present. In hepatocellular carcinomas cytokeratins 19 and 20 were frequently detected, but their cellular distribution was less closely associated with MBs. The ectopic expression of cytokeratins 19 and 20 appears to be related to MB formation and may take part in the derangement of the intermediate filaments during MB formation.

Topics: Antibodies, Monoclonal; Carcinoma, Hepatocellular; Child; Hepatolenticular Degeneration; Humans; Immunohistochemistry; Inclusion Bodies; Keratins; Liver; Liver Cirrhosis; Liver Diseases; Liver Diseases, Alcoholic; Liver Neoplasms

In the present study, the frequency and the distribution pattern of immunoreactive hepatocytic cytokeratin (CK) inclusions was investigated using the monoclonal antibody (MAb) CAM 5.2 detecting CKs 8, 18 and 19. The CK antigenicity of the inclusions was confirmed on frozen sections with MAbs for the CKs 7, 8, 17, 18 and 19. The frequency of hepatocytic CK aggregates was compared to the presence of non-alcoholic and alcoholic liver disease (ALD) as well as to the average all-year daily ethanol intake of 195 consecutive males subjected to medico-legal autopsy. Hepatocytic CK inclusions were infrequent in patients with normal liver histology, portal fibrosis and/or portal inflammation. In ALD, however, inclusions were observed in 35.6% of patients with fatty liver, in 63.2% of patients with alcoholic hepatitis, in 30.8% of patients with bridging fibrosis and in 60.0% of patients with liver cirrhosis. In all specimens studied, the inclusions were reactive only for CKs 8 and 18, CKs 7, 17, and 19 being unreactive. The frequency of inclusion bodies increased, paralleling increasing average all-year daily alcohol consumption. Compared to non-drinkers, a daily intake of between 40 and 80 g of absolute alcohol was associated with a statistically significantly (relative risk, RR = 6.6) increased risk of formation of aggregates. Similarly, daily consumption exceeding 80 g was related to increased (RR = 6.0) frequency of CK aggregates. The frequency of full-blown "classical" Mallory bodies (MBs) was, however, increased (RR = 8.9) only in patients with a daily intake exceeding 160 g.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Alcohol Drinking; Fatty Liver, Alcoholic; Hepatitis, Alcoholic; Humans; Immunohistochemistry; Inclusion Bodies; Keratins; Liver; Liver Cirrhosis, Alcoholic; Liver Diseases, Alcoholic; Male; Middle Aged

The patterns of cytokeratin as determined by murine monoclonal antikeratin antibody lu-5 (mAb lu-5) were quantitated in paraffin-embedded liver tissue from normal and diseased subjects. In tissue from healthy medical students, mAb lu-5 was found to decorate 2-4 periportal and 2-3 perivenular cell layers. Alcoholic liver disease was accompanied by a marked increase in intensity of mAb lu-5 antigen expression in zone I and III hepatocytes. Moreover, additional liver cells of both zones were progressively recruited, so that in advanced lesions all three lobular zones became positive. In mechanical as well as in drug-induced cholestasis, a similar increase of mAb lu-5 antigen expression was already observed in earlier stages of disease, including an earlier recruitment of zone II hepatocytes. In both alcoholic and cholestatic biopsies the intensity and extent of mAb lu-5 epitope expression increased with the duration and severity of disease. In primary biliary cirrhosis (PBC) and seemingly also in primary sclerosing cholangitis the increase and extent was more marked in zone I, the zone of assumed cholate accumulation. Changes in zone III, the territory of histologic cholestasis (bilirubinostasis), became evident only in late stages of PBC. Mallory bodies of alcoholic and cholestatic liver disease showed an identical mAB lu-5 antigen expression, thus giving rise to four different staining patterns. Changes of cytokeratin expression are similar in alcoholic and cholestatic liver diseases. In chronic viral hepatitis, however, cytokeratin alterations are discrete and restricted to precirrhotic/cirrhotic stages.

Topics: Antibodies, Monoclonal; Biopsy; Cholestasis; Chronic Disease; Epithelium; Hepatitis, Viral, Human; Humans; Keratins; Liver Diseases, Alcoholic; Paraffin Embedding; Reproducibility of Results; Retrospective Studies

The histologic significance of various changes in the bile ductal structures as observed by cytokeratin immunoperoxidase assay was studied in 122 patients with alcoholic liver disease (ALD) as a part of a large Veterans Administration Cooperative Study on alcoholic hepatitis. Four types of morphologic changes in the biliary structures were observed: 1) proliferation of interlobular bile ducts in the portal tracts; 2) marginal bile ductular proliferation at the periphery of the portal tracts; 3) appearance of bile duct type cells ("oval cells") in the liver parenchyma; and 4) metaplasia of bile duct epithelium to cells resembling hepatocytes. These bile ductal changes correlated strongly with liver fibrosis (p = 0.0003; 0.0003; 0.05; 0.0035, for 1, 2, 3, and 4, respectively), cirrhosis (p < 0.0001 for all four parameters), portal inflammation (p < 0.0001 for 1, 2, and 4; p = 0.0024 for "oval cells"), and with overall histologic severity scores (p < 0.0001; p = 0.0001; p = 0.0017; p = 0.0005, respectively). However, these changes did not correlate significantly with fatty change, parenchymal degeneration and necrosis, cellular infiltrate or Kupffer cell hyperplasia, suggesting that they are probably not the direct consequences of liver cell necrosis. Periportal piecemeal necrosis correlated significantly with both portal bile duct (p = 0.0041) and marginal (p = 0.0078) bile ductular proliferation. Among all these changes, only marginal bile ductular proliferation correlated significantly with Mallory bodies present both in the hepatocytes (p = 0.05) and the bile ducts (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Bile Ducts; Bile Ducts, Intrahepatic; Biopsy; Humans; Immunoenzyme Techniques; Keratins; Liver; Liver Diseases, Alcoholic; Metaplasia

A cytokeratin immunohistochemical study was performed on 40 liver biopsies diagnosed as alcoholic liver disease to further investigate the cytoskeletal changes occurring in this disease. On paraffin sections of 29 cases, a variable number of hepatocytes were reactive with a polyclonal antiserum that normally stains only bile ducts. Using monoclonal antibodies specific for a single cytokeratin polypeptide on cryostat sections, a variable number of hepatocytes were immunoreactive for cytokeratin no. 7 in 23 cases and also for cytokeratin no. 19 in seven cases. Both these polypeptides are restricted to bile duct cells in the normal liver. The number of hepatocytes positive for bile duct-type cytokeratins increased and their location changed with the severity of the disease. Mallory bodies were reactive with monoclonal antibodies CAM 5.2 and anti-cytokeratin no. 18 but unreactive with anti-cytokeratin no. 8. except in one case. In two cases, Mallory bodies reactive with both monoclonal antibodies anti-cytokeratin no. 7 and anti-cytokeratin no. 19 were found. These results clearly indicate that hepatocytes in alcoholic liver disease can express immunoreactivity for bile duct-type cytokeratins. Our data also demonstrate heterogeneity in the composition of Mallory bodies. Whether hepatocytes expressing bile duct-type cytokeratins are the precursors of Mallory body-containing cells is not clear at present.

Topics: Antibodies, Monoclonal; Bile Ducts, Intrahepatic; Humans; Immunoenzyme Techniques; Keratins; Liver Diseases, Alcoholic; Staining and Labeling

Aggregation and derangement of cytokeratin intermediate filaments are thought to be the key mechanism in the formation of Mallory bodies in alcoholic liver disease (ALD). To study the incidence and patterns of intracellular distribution of aggregated cytokeratin and to determine its utility as a diagnostic marker of ALD, 108 liver biopsy specimens from patients with various liver abnormalities were examined by an avidin--biotin peroxidase complex technique on paraffin section using a monoclonal antibody to cytokeratins (Hybritech). In normal liver (n = 11), only bile duct epithelium was positive. Both bile ducts and hepatocytes were positive in pathologic livers (n = 97). In ALD, 82 per cent of cases (42 of 51) showed cytokeratin positivity versus 15 per cent (seven of 46) in nonalcoholic liver disease (e.g., chronic hepatitis, nonalcoholic cirrhosis, cholestasis, and primary biliary cirrhosis). The highest incidence (100 per cent, 37 of 37) of positivity was obtained in cases with alcoholic hepatitis and cirrhosis compared with only 36 per cent (five of 14) in alcoholic fatty liver. Mallory bodies were found by the immunoperoxidase method in 71 per cent of cases (30 of 42) versus in 40 per cent (17 cases) by hematoxylin--eosin stain. In alcoholic fatty liver and alcoholic hepatitis, centrilobular hepatocytes showed cytokeratin positivity, whereas such reactivity was seen predominantly at the periphery of the regenerative nodules in alcoholic cirrhosis. A rare periportal hepatocyte was positive in the nonalcoholic group. These findings suggest that the differential distribution patterns of aggregated cytokeratin may be helpful in differentiating alcoholic from nonalcoholic liver diseases.

Topics: Antibodies, Monoclonal; Biopsy; Epitopes; Humans; Immunoenzyme Techniques; Intermediate Filaments; Keratins; Liver; Liver Diseases; Liver Diseases, Alcoholic

The distribution of tissue polypeptide antigen (40 kD molecular weight) in normal adult and fetal liver, and in liver disease was investigated and compared with the distribution of low and high molecular weight cytokeratins. In normal liver tissue polypeptide antigen was found only in bile duct epithelium; this distribution is similar to that of high molecular weight cytokeratin, but differs from that of low molecular weight cytokeratins. In liver disease it was found in areas of ductular transformation; in Mallory's bodies; and in alcoholic liver disease and primary biliary cirrhosis in some hepatocytes that did not contain Mallory's bodies.

Topics: Adult; Antigens; Bile Ducts, Intrahepatic; Fetus; Humans; Keratins; Liver; Liver Cirrhosis, Biliary; Liver Diseases; Liver Diseases, Alcoholic; Molecular Weight; Peptides; Tissue Polypeptide Antigen

Rhodamine B staining in conjunction with fluorescence microscopy is shown to demonstrate Mallory bodies. Mallory body morphology, localization, and distribution in hepatocytes from griseofulvin-fed mice, human hepatoma, and human alcoholics were similar to those observed in the same tissues after conventional staining methods for Mallory bodies. The presence of these inclusions was further confirmed by specific cytochemical localization with indirect immunoperoxidase labeling, horseradish peroxidase labeling, and electron microscopy. Other tinctorial or histochemical procedures previously used for keratin or prekeratin (modified Mallory stain, Kreyberg method, Pauly method for histidine) also stained Mallory bodies for study with white light microscopy but with decreasing sensitivity respectively. Mallory bodies from mouse and human liver both appear to contain a keratin-like moiety. This entity may be simply, rapidly, and permanently stained with rhodamine B, and selectively and reproducibly demonstrated with fluorescence microscopy.

Topics: Animals; Carcinoma, Hepatocellular; Endoplasmic Reticulum; Griseofulvin; Humans; Keratins; Liver; Liver Diseases, Alcoholic; Liver Neoplasms; Mice; Microscopy, Fluorescence; Rhodamines; Staining and Labeling; Xanthenes