Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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Mild iron overload in chronic hepatitis C is associated with liver fibrosis, hepatitis C virus (HCV) genotype 1b infection, and an impaired response to interferon therapy. In this study we evaluated whether polymorphisms in the hemochromatosis gene HFE and the transferrin receptor gene TFR1 are associated with these typical findings. The study considered 246 HCV-infected patients and 200 blood donors as controls, in which C282Y, H63D, and S65C mutations ( HFE) and the S142G polymorphism ( TFR1) were detected. HCV genotype, serum ferritin levels, stainable intrahepatic iron, and grade of fibrosis according to the METAVIR score (F0-F4) were determined. In HCV-infected patients, heterozygosity for the C282Y mutation in HFE was significantly associated with elevated serum ferritin levels, stainable liver iron, and advanced fibrosis or cirrhosis (F2-F4). By multivariate logistic regression analysis the odds ratio for the development of advanced fibrosis or cirrhosis (F2-F4) was 2.5 for HCV-infected patients carrying a heterozygous C282Y mutation and 4.8 for HCV-infected patients with C282Y/H63D and C282Y/S65C compound heterozygosity. Heterozygosity for the C282Y mutation in HFE contributes to iron accumulation and fibrosis progression in chronic hepatitis C.
J Mol Med (Berl) 2003 Dec
PMID:Hemochromatosis and transferrin receptor gene polymorphisms in chronic hepatitis C: impact on iron status, liver injury and HCV genotype. 1476 Aug 28

Current therapies for chronic hepatitis B virus (HBV) infection are limited in their effect on viral gene expression and replication. Recent reports have shown that RNA interference can be induced in mammalian cells by short interfering RNA duplexes (siRNA). Here we studied the effects of an HBV-specific 21-bp siRNA targeted to the surface antigen region (HBsAg), where three major viral mRNAs overlap, on HBV gene expression and replication both in a cell culture system and in a mouse model for HBV replication. Transfection of siRNA into HepG2.2.15 cells, which constitutively produce HBV particles, caused a significant reduction in viral RNA production that was accompanied by a >80% drop in the secretion of viral HBsAg and HBeAg into the medium. The effect of RNAi was tested in vivo in a mouse model that we have developed for HBV infection, which entails hydrodynamic injection of a plasmid bearing the HBV genome into tail veins of mice. Injection of the HBV plasmid induces viral replication and generation of HBV viral particles detectable in the mouse sera. Co-injection of the HBV plasmid together with siRNA caused a significant inhibition in the level of viral transcripts, viral antigens, and viral DNA detected in the livers and sera of the treated mice relative to control animals. Results suggest that siRNA is capable of inhibiting HBV replication in vivo and thus may constitute a new therapeutic strategy for HBV infection.
Mol Ther 2003 Nov
PMID:Small interfering RNA inhibits hepatitis B virus replication in mice. 1459 10

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, usually arising from a background of chronic inflammatory disease. Tumor necrosis factor alpha (TNF-alpha) is a pro-inflammatory cytokine produced in response to tissue injury, endotoxin exposure or infection and TNF-alpha signalling in hepatocytes is associated with an increase in oxidative stress. DNA is vulnerable to reactive oxygen species (ROS)-induced damage, which is highly mutagenic. Cells respond to DNA damage through the stabilisation of the tumor suppressor p53, which maintains genomic fidelity through induction of a cell cycle arrest in order to allow repair or elimination of the damaged cell through apoptosis. This study was carried out to determine if TNF-alpha caused oxidative DNA damage in primary cultures of murine hepatocytes and whether any damage would result in the induction of the tumor suppressor p53 and cell-cycle arrest. Using a modified Comet assay, to measure DNA damage we have demonstrated that TNF-alpha causes the formation of 8-oxo-deoxyguanosine (8-oxodG), an established marker of oxidative DNA damage, and a lesion associated with chronic hepatitis in human livers. In addition, the increase in DNA damage did not result in p53 stabilisation and TNF-alpha caused an increase in cell-cycle progression. We believe that this study indicates a possible putative role for TNF-alpha in the early stages of malignant transformation of hepatocytes.
Int J Mol Med 2003 Dec
PMID:TNF-alpha induced DNA damage in primary murine hepatocytes. 1461 62

Primary iron overload may be relatively common in African Americans, but its cause is incompletely understood. Thus, we evaluated genotype and phenotype characteristics of unselected African American index patients with primary iron overload who reside in central Alabama. All had hepatic iron concentration > or =30 micromol/g dry wt or > or =2.0 g of iron mobilized by phlebotomy to achieve iron depletion. Genotype analyses were performed in African American control subjects from the same region. There were 23 patients (19 men, 4 women); mean age at diagnosis was 52 +/- 12 years (1 SD) (range 32-69 years). Nine (39.1%) reported that they consumed > or =45 g of ethanol daily; five had chronic hepatitis C. Eight had some form of hemoglobinopathy or thalassemia. Mean serum transferrin saturation was 56 +/- 28% (range 15-100%). The geometric mean serum ferritin at diagnosis was 1076 ng/mL [95% confidence interval 297-3473 ng/mL]. Increased stainable liver iron was observed in hepatocytes only in 4 patients, in macrophages only in 8 patients, and in hepatocytes and macrophages in 8 patients. The mean quantity of iron mobilized by phlebotomy (corrected for iron absorbed during treatment) was 5.3 +/- 2.0 g (range 4.0-8.4 g). Iron removed by phlebotomy was greater in patients with hemoglobinopathy or thalassemia than in those without these forms of anemia (6.6 +/- 1.3 g vs 3.9 +/- 1.6 g, respectively; P = 0.0144). Daily consumption of > or =45 g of ethanol or chronic hepatitis C was not associated with an increased or decreased amount of phlebotomy-mobilized iron, on the average. The percentage of index patients positive for HFE C282Y was greater than that of controls (P = 0.0058). The respective percentages of phenotype positivity for HFE H63D, D6S105(8), and HLA-A*03 were similar in patients and controls. HFE S65C, I105T, and G93R were not detected in index or control subjects. Two of 13 patients were heterozygous for the ferroportin allele nt 744 G-->T (Q248H), although the phenotype frequency of this allele was similar in patients and 39 controls. Synonymous ferroportin alleles were also detected in some patients. The ceruloplasmin mutation nt 1099C-->T (exon 6; Arg367Cys) was detected in 1 of 2 patients tested. Abnormal alleles of beta-2 microglobulin, Nramp2, TFR2, hepcidin, or IRP2 alleles were not detected in either of the 2 patients so tested. We conclude that primary iron overload in African Americans is not the result of the mutation of a single gene. HFE C282Y, ferroportin 744 G-->T, and common forms of heritable anemia appear to account for increased iron absorption or retention in some patients.
Blood Cells Mol Dis
PMID:Genotypic and phenotypic heterogeneity of African Americans with primary iron overload. 1463 44

The hepatitis C virus (HCV) is a major causative agent of chronic hepatitis and hepatocellular carcinoma. The development of alternative antiviral therapies is warranted because current treatments for the HCV infection affect only a limited number of patients and lead to significant toxicities. The HCV genome is exclusively present in the RNA form; therefore, ribozyme strategies to target certain HCV sequences have been proposed as anti-HCV treatments. In this study, we determined which regions of the internal ribosome entry site (IRES) of HCV are accessible to ribozymes by employing an RNA mapping strategy that is based on a trans-splicing ribozyme library. We then discovered that the loop regions of the domain IIIb of HCV IRES appeared to be particularly accessible. Moreover, to verify if the target sites that were predicted to be accessible are truly the most accessible, we assessed the ribozyme activities by comparing not only the trans-splicing activities in vitro but also the trans-cleavage activities in cells of several ribozymes that targeted different sites. The ribozyme that could target the most accessible site identified by mapping studies was then the most active with high fidelity in cells as well as in vitro. These results demonstrate that the RNA mapping strategy represents an effective method to determine the accessible regions of target RNAs and have important implications for the development of various antiviral therapies which are based on RNA such as ribozyme, antisense, or siRNA.
J Biochem Mol Biol 2003 Nov 30
PMID:Identification of the most accessible sites to ribozymes on the hepatitis C virus internal ribosome entry site. 1465 71

The extracellular matrix (ECM) expression is subject to distinct changes during ontogeny, and the natural course of liver fibrosis in neonates is thought to differ from that in adults. We compared the expression and distribution of main ECM components between neonatal and adult liver fibrosis. Liver biopsies from infants with neonatal cholestasis and fibrosis were compared to adult biopsies exhibiting an equivalent stage of fibrosis. All biopsies were examined by immunohistochemistry (indirect ABC method) for the ECM proteins, collagens I, III, IV, and VI, laminin, and fibronectin. Infants (aged 1-8 months) with neonatal hepatitis (n = 3), extrahepatic biliary atresia (EHBA) (n = 5), and normal histology (n = 2) were compared with 9 adults (aged 17-70 years) with chronic hepatitis (n = 3), primary biliary cirrhosis (PBC) (n = 4), and normal histology (n = 2). Collagens I, III, and IV and fibronectin were significantly increased in neonatal hepatitis with mild fibrosis (score < or = 4) compared to adults with an equivalent fibrosis stage. This increase was particularly notable in perisinusoidal spaces. Laminin expression was increased in portal and perisinusoidal spaces both in neonatal hepatitis and extrahepatic biliary atresia with mild fibrosis. In infants with moderate to severe fibrosis (score > or = 6), only collagen I was increased in comparison to adults, whereas collagen VI expression was identical in all groups, irrespective of the degree of fibrosis. Expression of matrix proteins was not different in infants and adults without fibrosis. The increased perisinusoidal deposition of certain ECM components in infants with active hepatitis and mild fibrosis may point to an underlying difference in the mechanism or stimulus of fibrogenesis in neonates as compared to adults.
Pediatr Pathol Mol Med
PMID:Divergent patterns of extracellular matrix protein expression in neonatal versus adult liver fibrosis. 1469 30

The effect of IgG purified from the sera of healthy persons and patients with primary biliary cirrhosis (PBC) and chronic hepatitis (CH) on ADP dependent respiration (oxidative phosphorylation) in skinned muscle fibers from rat oxidative muscles (heart and M. soleus) and glycolytic skeletal muscle (M. gastrocnemius) was studied. The results show that IgG from three different sources inhibited the rate of respiration by 13, 44 and 42%, respectively, these effects being equally expressed in both types of oxidative muscles, whereas no inhibition was observed in glycolytic muscle. The following washout of unbound IgG did not abolish the inhibition of respiration suggesting that the specific interaction of IgG with antigens had taken place. Laser confocal analysis revealed binding of IgG predominantly to the sarcomeric structures such as Z-disk and M-lines in the cardiomyocytes. The staining of IgG within Z-disks and intermitochondrial space coincided throughout the muscle cells so that transversally serial spaces, each containing mitochondria and adjacent sarcomere, became clearly visible. When the IgG from a CH patient was incubated with the skinned myocardial fibers of the desmin knockout mice, its binding to Z-disks and the sarcomeric area was found to be similar to that in normal cardiac muscle. However, the transversal staining pattern was disintegrated, because of the slippage of the myofibrils in relation to each other and accumulation of mitochondria between them. These observations support the recent hypothesis that in oxidative muscles the mitochondria and adjacent sarcomeres form complexes, termed as the intracellular energetic units, ICEUs. Moreover, they indicate that human autoantibodies can be useful tools for localizing the proteins responsible for formation of ICEUs and modulation of their function. Thus, it appears that the proteins associated with the Z-disks and M-lines may participate in formation of ICEUs and that binding of IgG to these proteins decreases the access of exogenous adenine nucleotides to mitochondria, which manifests as decreased rate of ADP-dependent respiration.
Mol Cell Biochem
PMID:IgG from patients with liver diseases inhibit mitochondrial respiration in permeabilized oxidative muscle cells: impaired function of intracellular energetic units? 1497 89

Antiviral drug lamivudine has been widely used in the treatment of hepatitis B. However, it was demonstrated recently, that therapy by the drug is related with the selection of viral strains carrying mutations in C-domain of DNA polymerase/reverse transcriptase (YMDD-mutation). The mutation is the cause of resistance to lamivudine. An increase of the mutant population in the course of a long-term lamivudine therapy makes the monotherapy by the discussed drug ineffective. Therefore, the monitoring of YMDD mutations is important in the treatment of chronic hepatitis B (CHB) by lamivudine. The results of using the allele-specific polymerase chain reaction (AS PCR) for the detection of YMDD mutations are presented in the offered case study. Sera from CHB patients were used in research. A system of allele-specific primers was designed for the HBV DNA region from base 720 to base 978, which enabled us to detect possible substitutions in an appropriate ATG-triplet, i.e. the YMDD-mutations locus--positions 741-743 of the HBV DNA nucleotide sequence. The obtained DNA fragments were analyzed by electrophoresis in the agar gel. AS PCR was used to test the sera of HBV patients. Samples were detected, which contained the "wild" virus type, different YMDD mutations and mixed (the "wild" type plus a mutation) HBV variants. It was shown that reliable AS PCR results could be obtained only in those sample, whose HBV titer is no more than 10(6) genome per ml. The offered AS PCR procedure can be applied in the detection of YMDD mutations of HBV DNA in sera of patients with hepatitis B. Sera with a high virus titer must be diluted, prior to testing, to 10(6) genomes per ml. to ensure the reliable AS PCR results.
Mol Gen Mikrobiol Virusol 2004
PMID:[Detection of YMDD mutations in hepatitis B virus DNA with the use of allele specific polymerase chain reaction]. 1502 1

Overexpression of cyclooxygenase 2 (COX-2) is associated with tumorigenesis in a number of human cancers. Recently, COX-2 overexpression has also been reported in hepatocellular carcinoma (HCC), especially in well-differentiated HCC. However, doubt has been cast on these claims concerning HCC. Here we show by Western blot analysis that COX-2 protein level is higher in the adjacent chronic hepatitis liver than in the tumors themselves. We also show, by immunohistochemical staining, that the mean intensity of COX-2 expression in cirrhotic liver specimens is significantly higher than in normal livers and in moderately-differentiated HCC. In addition, the frequency and level of expression of COX-2 in poorly differentiated HCC was similar to that of well-differentiated HCC. Nevertheless all types of HCC expressed more COX-2 than normal livers, and immunofluorescence staining showed cytoplasmic expression of COX-2 in 7 out of 8 human hepatoma cell lines. Collectively, our data suggest that both chemoprevention and chemotherapy of HCC by COX-2 specific inhibitors should be considered. Our data also suggest that COX-2 may play a role in the advanced stages as well as early stages of hepatocarcinogenesis.
Mol Cells 2004 Feb 29
PMID:The correlation between cyclooxygenase-2 expression and hepatocellular carcinogenesis. 1505 24

Interferon-alpha (INF-alpha) is the only effective drug for the treatment of chronic hepatitis B. However it can produce severe side effects during treatment. Encapsulation of INF-alpha in liposomes may reduce the side effects and enhance its therapeutic activity. We evaluated the activity of free (nonencapsulated) and liposome-encapsulated INF-alpha on in vitro cultured Chang liver cells by measuring the metallothionein gene (MT-IIA). INF-alpha was encapsulated in different liposomal formulations, Dimyristoylphosphatidylcholine (DMPC), Dioleyl-phosphatidyl-ethanolamine/Dimyristoylphosphatidylcholine (DOPE/DMPC) and DOPE/Dimyristoylphosphatidylglycerol (DOPE/DMPG). Chang liver cells were incubated for 10 hours with 100 units/ml of free or one of the aforementioned liposomal INF-alpha formulations. We also evaluated the extended-time effects of DMPC liposomal formulations of INF-alpha and the non-encapsulated (free) INF-alpha on Chang liver cells after 12, 24 and 36 h of incubation. Total RNA was extracted and signals on Northern blots were densitometrically compared following hybridization with MT-IIA and beta actin probes. All INF-alpha formulations (free and liposomal) induced higher MT-IIA gene levels compared to non-treated control cells. Levels of MT-IIA mRNA expression were 80.9, 73.6, 43.9, and 35.3% over the control for the free, DOPE/DMPG, DMPC and DOPE/DMPC liposomal INF-alpha, respectively. The ratios of MT-IIA mRNA amounts expressed after the Chang liver cells were incubated with INF-alpha encapsulated in DMPC liposomes and the MT-IIA mRNA expressed after incubation with nonencapsulated INF-alpha are 0.7, 0.52 and 0.82 at 12, 24, and 36 hours, respectively. The results indicate that the MT-IIA mRNA level depends on the liposomal formulation of INF-alpha, and the sustained-time effect of the INF-alpha encapsulated in DMPC liposomes is parallel to that of nonencapsulated INF-alpha over a period of 36 hours.
Res Commun Mol Pathol Pharmacol 2002
PMID:Targeting hepatocytes with liposomal interferon-alpha: effect on metallothionein gene induction. 1508 Apr 96


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