Minoru Ono

Serum-manganese-superoxide dismutase: normal values and increased levels in patients with acute myocardial infarction and several malignant diseases determined by an enzyme-linked immunosorbent assay using a monoclonal antibody

An enzyme-linked immunosorbent assay (ELISA) has been developed for human manganese-superoxide dismutase (Mn-SOD), using a specific monoclonal antibody raised against the purified enzyme. The Mn-SOD molecule comprises four identical sub-units and this permitted the development of a symmetrical assay, using the same monoclonal antibody as both capture and detector. The assay offers a specific, sensitive and convenient means of measuring immunoreactive Mn-SOD in human sera. Under optimum conditions, the sensitivity of the assay permits the detection of 2-200 ng of purified Mn-SOD from human liver. The mean serum Mn-SOD levels of normal healthy males and females were 99.8 +/- 24.8 (mean +/- SD) and 88.8 +/- 20.8 (mean +/- SD), respectively. A high level of the enzyme was found in the sera of patients with acute myocardial infarction as well as malignant diseases such as acute myeloid leukemia, primary hepatoma and gastric cancer. This is the first report of an ELISA using a monoclonal antibody specific for a distinct epitope of Mn-SOD.

Induction of Mn-superoxide dismutase by Tumor Necrosis Factor, Interleukin-1 and Interleukin-6 in human hepatoma cells

Effects of Tumor Necrosis Factor (TNF), Interleukin-1 (IL-1), Interleukin-6 (IL-6) and Interferon-gamma (IFN-gamma) on the expression of Mn-superoxide dismutase (Mn-SOD) protein were investigated in human hepatoma cells, Hu-H1, which revealed resistance to the cytotoxicity of TNF and IL-1. Both TNF and IL-1 enhanced the Mn-SOD production to the level of 30- to 40-fold. IL-6 also increased the enzyme protein to 2- to 3-fold of the basal level without any cell proliferative effect. A specific antibody against IL-6 almost completely inhibited the induction of Mn-SOD. IL-6, as well as TNF and IL-1, appears to play some role in the Mn-SOD protein expression in human hepatoma cells.

Proline-rich antimicrobial peptide, PR-39 gene transduction altered invasive activity and actin structure in human hepatocellular carcinoma cells

SummaryPR-39 is an endogenous proline-rich antimicrobial peptide which induces the synthesis of syndecan-1, a transmembrane heparan sulphate proteoglycan involved in cell-to-matrix interactions and wound healing. Previously, we revealed that the expression of syndecan-1 was reduced in human hepatocellular carcinomas with high metastatic potential and speculated that syndecan-1 played an important role in inhibition of invasion and metastasis. It is assumed that a modification of this process with PR-39 and syndecan-1 may result in a new strategy by which it can inhibit the invasion and metastasis. Therefore, we transduced a gene of PR-39 into human hepatocellular carcinoma cell line HLF, which shows a low expression of syndecan-1 and a high in vitro invasive activity, and examined whether this procedure could reduce the invasive activity of tumour cells. In two transfectants with PR-39 gene, the syndecan-1 expression was induced and the invasive activity in type I collagen-coated chamber was inhibited. Moreover, these transfectants showed the suppression of motile activity assayed by phagokinetic tracks in addition to the disorganization of actin filaments observed by a confocal imaging system. In contrast, five transfectants with syndecan-1 gene in the HLF cells revealed suppression of invasive activity but did not alter the motile activity and actin structures of the cell. These results suggest that PR-39 has functions involved in the suppression of motile activity and alteration of actin structure on human hepatocellular carcinoma cells in addition to the suppression of invasive activity which might result from the induction of syndecan-1 expression.

Immunohistochemical detection of 4-hydroxy-2-nonenal-modified-protein adducts in human alcoholic liver diseases

4-Hydroxy-2-nonenal (HNE) is one of the major components of lipid peroxidation product and has been shown to react with proteins to form HNE-protein adducts. HNE-protein adducts are relatively stable and can be used as a marker of radical-mediated cellular damage. We report herein the immunohistochemical analysis of HNE-protein adducts in human alcoholic liver diseases using a specific monoclonal antibody HNEJ-2. Cytoplasm of hepatocytes and bile duct epithelia was positively stained for HNE-protein adducts, and the nucleus was negligibly stained. The immunohistochemical intensity of hepatocytes was classified into three groups: strong, moderate, and faint staining. Strong staining was found in 43% of alcoholic liver diseases and in 4% of viral liver diseases. Hepatocytes of alcoholic liver diseases contained a higher amount of HNE-protein adducts than those of viral liver diseases, and the difference was statistically significant (p = 0.005; chi2 test). Semiquantitative analysis of the histological intensities of HNE-protein adducts and iron indicated a significant positive correlation (p = 0.084; Spearmans rank correlation). The localization of HNE-protein adducts and iron in hepatocytes appeared to be identical. These data suggested the correlation between HNE-protein adducts and iron. Our results indicate that HNE-protein adducts, a marker of oxidative stress-induced damage, are increased in human alcoholic liver damage, and that hepatic siderosis may act on the production of free radicals.

Measurement of Immunoreactive Prothrombin Precursor and Vitamin-K-Dependent Gamma-Carboxylation in Human Hepatocellular Carcinoma Tissues: Decreased Carboxylation of Prothrombin Precursor as a Cause of Des-Gamma-Carboxyprothrombin Synthesis

Des-gamma-carboxyprothrombin is an abnormal prothrombin which is drastically increased in the plasma of patients with hepatocellular carcinoma. To investigate the process of the abnormal prothrombin synthesis, the amount of prothrombin precursor was measured with an enzyme-linked immunosorbent assay using a specific antibody directed to human prothrombin; the vitamin-K-dependent gamma-carboxylation of prothrombin precursor was determined in human liver tissues. The tissue content of prothrombin precursor was increased in hepatoma tissues compared with noncancerous liver tissues, while the vitamin-K-dependent carboxylation of prothrombin precursor was markedly decreased in hepatoma tissues of the patients with increased plasma des-gamma-carboxyprothrombin. The present study indicates that in hepatocellular carcinoma an increase in prothrombin precursor concentration does not induce vitamin-K-dependent carboxylase activity, which is ordinarily observed in normal liver; probably an overproduction of prothrombin precursor with reduced gamma-carboxylation causes an increase in plasma des-gamma-carboxyprothrombin in patients with hepatocellular carcinoma.

Reduced expression and rare genomic alteration of nm23-H1 in human hepatocellular carcinoma and hepatoma cell lines.

Abstract: We investigated the expression and genomic alteration of nm23-H1 (which encodes a nucleoside diphosphate, kinase A) in 12 human hepatocellular carcinomas (HCCs) and four hepatoma cell lines. The expression of nm23-H1 protein was significantly reduced in HCCs with intrahepatic metastasis (72%) compared with expression in HCCs without intrahepatic metastasis (38%). However, in two of three HCCs examined that had marked reduction of nm23-H1 protein, the nm23-H1 mRNA level was not reduced. A hepatoma cell line, HLF (phenotype, poorly differentiated carcinoma) revealed marked reduction of nm23-H1 protein compared with two other hepatoma cell lines, HuH-1 and HuH-2, although the mRNA level was similar in the three cell lines. No allelic deletion of the nm23-H1 gene was detected in the 12 HCCs examined. No point mutation in the coding region of the nm23-H1 gene was observed in any of the 12 HCCs or the four hepatoma cell lines. These findings suggest that: (i) the expression of nm23-H1 protein is inversely associated with high metastatic potential of HCC, (ii) regulation of nm23-H1 expression may occasionally occur at both the transcriptional and post-transcriptional levels in HCC; and (iii) genomic alteration of nm23-H1 is a rare event in HCC.

Increase of serum des-gamma-carboxy prothrombin in alcoholic liver disease without hepatocellular carcinoma.

The purpose of this study is to determine serum des-gamma-carboxy prothrombin (DCP) levels in benign liver diseases by a new sensitive method, and to demonstrate the elevation of serum DCP in alcoholic liver disease (ALD) without hepatocellular carcinoma (HCC). Median values of serum DCP were 16.2 mAU/ml (range: 3.2 to 1570 mAU/ml) in ALD and 16.7 mAU/ml (1.2 to 75.4 mAU/ml) in viral liver disease (VLD). Using the cut-off value of 40 mAU/ml as a tumor marker for HCC, 21% (11/52) was positive in ALD and 2% (1/57) was positive in VLD (p= 0.0014, Fishers exact probability test), and 27% (9/33) was positive in alcoholic liver cirrhosis and 3% (1/39) was positive in viral liver cirrhosis (p = 0.0042, Fishers exact probability test). The positive rate of DCP was significantly (p< 0.001, Spearmans rank correlation test) correlated with the severity of liver disease in ALD. Serum vitamin K level was not decreased in cases with ALD. In a demonstrable case, serum DCP was decreased after abstinence and was increased again after the beginning of ethanol intake, suggesting the involvement of ethanol to the elevation of serum DCP in ALD. In conclusion, serum DCP was significantly elevated in ALD, compared with VLD, although the mechanism of the elevation of DCP was not clarified. Ethanol intake may act, in part, on the increase of serum DCP in ALD.

Changes in free radical-metabolizing enzymes and lipid peroxides in the liver of Long-Evans with cinnamon-like coat color rats.

We report changes in free radical-metabolizing enzymes and the increased generation of lipid peroxides associated with extreme metal accumulation in the liver of the Long-Evans with cinnamon-like coat color (LEC) rat, a new mutant strain displaying hereditary hepatitis and subsequent hepatocellular carcinoma. The activity of free radical-metabolizing enzymes and lipid peroxides, and the concentration of metal in the liver were determined sequentially after birth. Mn-superoxide dismutase activity significantly increased immediately after the onset of hepatitis in LEC rats, whereas no remarkable change was observed in control rats. Cu, Zn-superoxide dismutase activity in LEC rats was similar to that in control rats. Glutathione reductase activity increased, while glutathione peroxidase activity was lower in LEC rats than in control rats throughout the observation periods. Lipid peroxides, estimated by thiobarbituric acid reaction, also increased 4-to 5-fold immediately after the onset of hepatitis in LEC rats. Copper concentration was 30-to 50-fold higher in the liver of LEC rats than in control rats, and the iron content also increased significantly before and after the onset of hepatitis. These findings suggested that an oxidant injury generated by toxic metals could be one of the factors responsible for hepatocellular damage in this unique hereditary hepatitis.

Primary biliary cirrhosis associated with idiopathic thrombocytopenic purpura.

A case of primary biliary cirrhosis (PBC) associated with idiopathic thrombocytopenic purpura (ITP) is reported. The patient is a 59-year-old man. When he was 49 years old, he was diagnosed with ITP and received steroid therapy that successfully increased platelet numbers. However, the steroid therapy failed to normalize the elevated gamma-glutamyl transpeptidase. Ten years after this episode, he suffered from general itching and malaise and exhibited a gradual increase of serum biliary enzyme levels. Immunologically, IgM was increased and anti-mitochondrial antibody was positive. Histological findings of liver needle biopsy showed chronic non-suppurative destructive cholangitis, confirming the diagnosis of PBC. To date, very few PBC cases associated with ITP have been reported. Our case is the second one in Japan. PBC and ITP in our patient seemed to develop simultaneously, but the effect of steroid therapy on the two conditions was different. This result suggests that the autoimmune process may have been different in PBC and ITP in the present patient.

Serum immunoreactive β-glucuronidase determined by an enzyme-linked immunosorbent assay in patients with hepatic diseases

An enzyme-linked immunosorbent assay (ELISA) was developed for human beta-glucuronidase, using a specific polyclonal antibody raised against the purified enzyme. beta-Glucuronidase from human liver consisted of three subunits with molecular mass of 76, 64 and 18 kDa. The assay offered a specific, sensitive and convenient means of measuring immunoreactive beta-glucuronidase in human sera. beta-Glucuronidase activity determined by the conventional method appeared to be extremely low, indicating that in human sera beta-glucuronidase exists in an enzymatically inactive form. The sensitivity of the assay permitted the detection of 1-100 ng of purified beta-glucuronidase. A mean serum level in normal subjects was 108 +/- 25 ng/ml (mean +/- S.D.). A high level of beta-glucuronidase was found in sera of patients with severe hepatocellular necrosis, including liver cirrhosis (152 +/- 130 ng/ml) and chronic active hepatitis (220 +/- 99 ng/ml), whereas no significant increase of the enzyme protein was observed in chronic persistent hepatitis (102 +/- 42 ng/ml). beta-Glucuronidase was also increased in sera of patients with primary hepatoma (156 +/- 125 ng/ml). The immunoreactive beta-glucuronidase determined in this assay was thought to be a supplementary serological indicator for hepatocellular necrosis.