Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A recently discovered bacterium, Helicobacter hepaticus, infects the intrahepatic bile canaliculi of mice, causing a severe chronic hepatitis culminating in liver cancer. Thus, it affords an animal model for study of bacteria-associated tumorigenesis including H. pylori-related gastric cancer. Reactive oxygen species are often postulated to contribute to this process. We now report that hepatitis of male mice infected with H. hepaticus show significant increases in the oxidatively damaged DNA deoxynucleoside 8-hydroxydeoxyguanosine, with the degree of damage increasing with progression of the disease. Perfusion of infected livers with nitro blue tetrazolium revealed that superoxide was produced in the cytoplasm of hepatocytes, especially in association with plasmacytic infiltrates near portal triads. Contrary to expectations, Kupffer cells, macrophages, and neutrophils were rarely involved. However, levels of cytochrome P450 (CYP) isoforms 1A2 and 2A5 in hepatocytes appeared to be greatly increased, as indicated by the number of cells positive in immunohistochemistry and the intensity of staining in many cells, concomitant with severe hepatitis. The CYP2A5 immunohistochemical staining co-localized with formazan deposits resulting from nitro blue tetrazolium reduction and occurred in nuclei as well as cytoplasm. These findings suggest that CYP2A5 contributes to the superoxide production and 8-hydroxydeoxyguanosine formation, although reactive oxygen species from an unknown source in the hepatocytes leading to CYP2A5 induction or coincidental occurrence of these events are also possibilities. Three glutathione S-transferase isoforms, mGSTP1-1 (pi), mGSTA1-1 (YaYa), and mGSTA4-4, also showed striking increases evidencing major oxidative stress in these livers.
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PMID:Increased oxidative DNA damage and hepatocyte overexpression of specific cytochrome P450 isoforms in hepatitis of mice infected with Helicobacter hepaticus. 932 26

The nucleocapsid (N) protein of mouse hepatitis virus (MHV) and the cellular heterogeneous nuclear ribonucleoprotein A1 (hnRNP-A1) are RNA-binding proteins, binding to the leader RNA and the intergenic sequence of MHV negative-strand template RNAs, respectively. Previous studies have suggested a role for both N and hnRNP-A1 proteins in MHV RNA synthesis. However, it is not known whether the two proteins can interact with each other. Here we employed a series of methods to determine their interactions both in vitro and in vivo. Both N and hnRNP-A1 genes were cloned and expressed in Escherichia coli as glutathione S-transferase (GST) fusion proteins, and their interactions were determined with a GST-binding assay. Results showed that N protein directly and specifically interacted with hnRNP-A1 in vitro. To dissect the protein-binding domain on the N protein, 15 deletion constructs were made by PCR and expressed as GST fusion proteins. Two hnRNP-A1-binding sites were identified on N protein: site A is located at amino acids 1 to 292 and site B at amino acids 392 to 455. In addition, we found that N protein interacted with itself and that the self-interacting domain coincided with site A but not with site B. Using a fluorescence double-staining technique, we showed that N protein colocalized with hnRNP-A1 in the cytoplasm, particularly in the perinuclear region, of MHV-infected cells, where viral RNA replication/transcription occurs. The N protein and hnRNP-A1 were coimmunoprecipitated from the lysates of MHV-infected cells either by an N- or by an hnRNP-A1-specific monoclonal antibody, indicating a physical interaction between N and hnRNP-A1 proteins. Furthermore, using the yeast two-hybrid system, we showed that N protein interacted with hnRNP-A1 in vivo. These results thus establish that MHV N protein interacts with hnRNP-A1 both in vitro and in vivo.
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PMID:The nucleocapsid protein of coronavirus mouse hepatitis virus interacts with the cellular heterogeneous nuclear ribonucleoprotein A1 in vitro and in vivo. 1060 21

We have previously characterized a monoclonal antibody (SC1D7) that is directed to maltose-binding protein (MBP) of Escherichia coli and other closely related enteric bacteria. SC1D7 does not cross-react with proteins in eucaryotes and appears to be a highly specific tool in immunochemical analyses. To better map the epitope, we took advantage of an available plasmid, pMAL-c2, that encodes the E. coli MBP-coding sequence and constructed plasmids to express MBP fragments. A construct containing the N-terminal portion of MBP does not react with SC1D7, whereas a second construct expressing glutathione S-transferase fused with the C-terminal half of MBP does react with SC1D7. To precisely define the epitope, random peptides displayed on M13 were used to react with SC1D7. Sequences of reactive peptides were aligned, and a consensus sequence of XDXRIPX was deduced. This sequence matches MBP with an amino acid stretch of KDPRIAA. To consolidate the mapping result, a sequence encoding this epitope was inserted into an expression vector and the resulting recombinant protein did react with SC1D7. Thereafter, this epitope was incorporated into a eucaryotic expression plasmid containing a previously defined hepatitis delta virus epitope for protein tagging. This two-epitope-tagging vector is useful in various molecular analyses. We demonstrate its usage for localization of a bacterial virulence factor in host cells. This vector should be applicable for high-throughput characterization of new open reading frames found in genome sequencing.
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PMID:Construction of a tagging system for subcellular localization of proteins encoded by open reading frames. 1128 47

AIM:To isolate mouse CCR5 cDNA (muCCR5) and study its expression in vivo.METHODS: Marathon PCR was used to isolate muCCR5 cDNA and two animal models were designed to investigate the gene expression in vivo, one was mouse fulminant hepatitis induced by Propionibacterium acnes (P.acnes) and the other was that with delayed type hypersensitivity reaction (DTH). A specific GST-NH2-terminus of muCCR5 fusion protein antibody F(ab')(2) was prepared and clarified. RT-PCR and immunohistochemical analysis were used to observe the expression level of CCR5 gene in mice.RESULTS: A positive reaction of mouse macrophage was found in DTH but not expressed in P.acnes induced fulminant hepatitis by RT-PCR and immunohistochemical analysis.CONCLUSION: This muCCR5 expression may be involved in an allergic processmediated by cellular immunity but not acute inflammatory reaction induced by P.acnes.
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PMID:CCR5 gene expression in fulminant hepatitis and DTH in mice. 1181 19

We have recently reported that anti-SLA seropositive autoimmune hepatitis (AIH) patients develop autoantibodies against glutathione S-transferase (GST). GSTs are multifunctional enzymes mediating hepatic detoxification of cytotoxic and genotoxic compounds and are also involved in biliary secretion. We have observed varying reactivity of individual AIH sera towards several GST isoenzymes. Since the GST subunits have very similar molar masses and therefore are not satisfactorily resolved by one-dimensional gel electrophoresis, we have performed their fractionation by reverse-phase high performance liquid chromatography (HPLC) to better separate the individual GST isoenzymes. 4 individual GST subunits were isolated as judged by electrophoretic analysis of the 4 distinct peaks. The identity of isolated proteins was unequivocally determined by protein sequencing. Isolated subtypes were loaded on 15% SDS gels and blotted. Immunoblotting was performed with eleven anti-SLA positive sera that displayed differential reactivity with total GSTs. Fractionation of the GSTs by HPLC did not impair their ability to react with specific autoantibodies. Interestingly, the majority of GST-positive AIH sera reacted with one or two GST subtypes, only two sera recognized 3 subunits. Ya was most prevalent autoantigen. Autoantibodies against Yb2 were detected solely in one serum. This pattern of reactivity indicates that individual patients' sera discriminate between GST subunits despite their sequence homology. It is well known that the GST variants differ within their amino-terminal part while the residual moiety is highly conserved. It would suggest that autoantibodies recognize distinct epitopes located within amino-terminus of individual GST variants.
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PMID:Anti-SLA seropositive autoimmune hepatitis sera recognize distinct subunits of glutathione S-transferase: high prevalence of the Ya autoantigen. 1203 Apr 35

The mutant strain Long-Evans Cinnamon (LEC) rat accumulates copper, resulting in spontaneous hepatitis and subsequent development of hepatocellular carcinomas (HCCs) in the liver, providing a promising model for investigation of the relationship between hepatitis induced by oxidative stress and hepatocarcinogenesis. We examined DNA strand breaks in peripheral blood cells and p53 expression in livers during acute and chronic hepatitis in LEC rats, along with preneoplastic lesions, and cell proliferation and apoptosis in non-cancerous portions of livers from LEC rats aged 7-115 weeks. Immunohistochemistry using antibodies against glutathione S-transferase placental-form (GST-P), proliferating cell nuclear antigen (PCNA), and in situ DNA nick labeling (TUNEL) were used. Long-Evans Agouti (LEA) rats, a sibling line of the LEC strain, were used as controls. In the LEC rats, DNA strand breaks and expression of p53 were significantly higher than that of LEA rats at 24 weeks of age. The number of GST-P-positive (GST-P+) foci/cm2 increased and peaked at 48 weeks old, and the areas rapidly expanded thereafter. The level of cell proliferation increased with the development of hepatitis and was highest at about 48 weeks old. The induction of apoptosis in LEC rats was transiently higher than that in LEA rats during the period from 24 to 34 weeks of age. However, the ratio of PCNA-positive cells to the apoptotic index showed a growth imbalance in favor of cell proliferation, supporting sustained net growth in LEC rats. These findings suggest that DNA damage, reflected in DNA strand breaks, plays a critical role in the development of hepatocellular preneoplastic foci, with an imbalance between high proliferation and relatively low apoptosis.
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PMID:DNA damage triggers imbalance of proliferation and apoptosis during development of preneoplastic foci in the liver of Long-Evans Cinnamon rats. 1223 13

Fumonisin B1 (FB1) is a naturally occurring mycotoxin produced by Fusarium verticillioides. Dietary exposure to FB1 has been linked to human cancer in certain parts of the world, and treatment with FB1 causes oval cell proliferation and liver tumors in rats. To study the potential role of oval (liver progenitor) cells in the cellular pathogenesis of FB1-induced liver tumors, we gave male F344 rats prolonged treatment with FB1 for 25 weeks, followed by return to control diet until 50 weeks ('stop study'). The time course of FB1-induced liver lesions was followed by examination of serial liver biopsies at set time intervals and post-mortem liver tissue at the end of the study. The effects of different FB1 treatment regimens (5 versus 25 weeks), as well as the modulating effect of 2-acetylaminofluorene (2-AAF), on the kinetics of oval cell proliferation and development of liver tumors were compared. Prolonged treatment with FB1 in normal diet caused persistent oval cell proliferation and generation of both hepatic adenomas and cholangiofibromas (CFs). These liver lesions occurred in the setting of chronic toxic hepatitis and liver fibrosis/cirrhosis, similar to that seen in human hepatocarcinogenesis. Some adenomas and CFs were dysplastic, and one post-mortem liver contained a hepatocellular carcinoma. OV-6+ oval cells were noted in close relation to proliferative neoplastic liver lesions, and some of these lesions expressed OV-6, suggesting that all these cell types were derived from a common progenitor cell. 2-AAF enhanced the size of FB1-induced glutathione S-transferase pi+ hepatocellular lesions and the incidence of CFs in post-mortem liver specimens, but this was not statistically significant. In conclusion, this study supports the involvement of dietary FB1 in liver carcinogenesis in male F344 rats. Oval cells may be the source of both the hepatocellular and cholangiocellular tumors induced by prolonged treatment with FB1. 2-AAF appears to have an enhancing effect on FB1-induced liver tumors, presumably due to its potent inhibitory effects on hepatocyte regeneration.
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PMID:Fumonisin B1-induced hepatocellular and cholangiocellular tumors in male Fischer 344 rats: potentiating effects of 2-acetylaminofluorene on oval cell proliferation and neoplastic development in a discontinued feeding study. 1498 22

Several phase I and phase II multi-drug metabolizing enzymes, such as CYP2D6, 3A4, and UGTA1, were reported to act as immunotargets in a subset of autoimmune hepatitis and hepatic autoimmunity. However, it is uncertain whether glutathione S-transferase (GST) A1-1, one of the phase II multi-drug metabolizing enzymes, is also an immunotarget in autoimmune hepatitis. So, in the present study, we investigated the frequency and significance of anti-GST A1-1 in sera from patients with autoimmune hepatitis. A total of 74 serum samples from patients with autoimmune hepatitis were examined in the present study. As controls, 20 serum samples from patients with primary biliary cirrhosis, 10 serum samples from patients with primary sclerosing cholangitis, 40 serum samples from patients with liver cirrhosis type B and C, 32 serum samples from patients with systemic lupus erythematosus, and 20 serum samples from normal controls were used. Anti-GST A1-1 antibody was determined by immunoblotting using the recombinant full-length GST A1-1 protein as the antigen. The immunofluorescent staining pattern of anti-GST A1-1 was investigated using rat liver and kidney sections. We compared clinicopathologic findings between anti-GST A1-1-positive and -negative autoimmune hepatitis patients. Anti-GST A1-1 was detected in 12 (16%) of 74 patients with autoimmune hepatitis, however, it was not detected in any control serum samples except for two patients with primary biliary cirrhosis. The immunofluorescence staining pattern of anti-GST A1-1 was found to be unique and different from those of anti-mitochondrial antibody or anti-liver-kidney microsome type 1 antibody. Anti-GST A1-1 coexisted with other autoantibodies such as anti-nuclear or anti-smooth muscle antibodies, but did not coexist with anti-soluble liver antigen/liver pancreas. Anti-GST A1-1-positive autoimmune hepatitis patients had severe clinical features and a poor prognosis compared with anti-GST A1-1-negative patients. These findings suggested that despite the low frequency, anti-GST A1-1 might be the marker of an early progression in autoimmune hepatitis.
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PMID:Frequency and significance of anti-glutathione S-transferase autoantibody (anti-GST A1-1) in autoimmune hepatitis. 1504 Oct 41

A new form of autoimmune hepatitis referred to as de novo, has been reported after liver transplantation during the past 5 years. The features are identical to those of classical autoimmune hepatitis (AIH), but the facts involved in the onset and outcome of this type of graft dysfunction are still unclear. The identification of antibodies directed to glutathione S-transferase T1 (GSTT1) in the sera of patients with de novo immune hepatitis led us to the description of an alloimmune reaction due to a GSTT1 genetic incompatibility between donor and recipient. We analyzed a cohort of 110 liver transplant patients treated in the liver transplant unit of our hospital during a period of 1 year, from September 2002 to October 2003. We found the following distribution of the GSTT1 genotypes (recipient/donor): +/+ = 66, +/- = 23, -/+ = 15, -/- = 6. Six of these patients were diagnosed with de novo immune hepatitis; all of them belong to the group of negative recipients with positive donors, and all produced anti-GSTT1 antibodies. This genetic combination is associated with a statistically significant increased risk of de novo immune hepatitis (IH) in liver transplant patients (P < .0001 by the Fisher exact test). In conclusion, our results clearly establish the importance of the GSTT1 genotype from donor and recipient of a liver transplant as a predictive marker for de novo IH. At the same time, we confirmed our initial results that only this particular donor/recipient combination triggers the anti-GSTT1 antibody production.
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PMID:Glutathione S-transferase T1 mismatch constitutes a risk factor for de novo immune hepatitis after liver transplantation. 1535 10

Hepatocellular carcinoma is usually preceded by chronic inflammation. However, the molecular mechanism in hepatocarcinogenesis is not well known. Recently, we reported that mitochondrial dysfunction plays an important role in hepatocarcinogenesis via the production of free radicals. Furthermore, we proved that L-carnitine effectively protects mitochondrial function in vivo. Therefore, we investigated whether long-term administration of L-carnitine could prevent hepatitis and subsequent hepatocellular carcinoma in Long-Evans Cinnamon rats that are often analyzed as a model of hepatocarcinogenesis. The results indicated that oxidative stress elicited from abnormally accumulated copper increased the amount of free fatty acids, thereby inducing mitochondrial dysfunction, resulting in cell death and enhanced secondary generation of reactive oxygen species, which were significantly inhibited by carnitine treatment. Finally, the occurrence of placental glutathione S-transferase-positive foci as a marker for preneoplastic lesions and hepatocarcinogenesis were significantly inhibited by L-carnitine. These facts suggest that mitochondrial injury plays an essential role in the development of hepatocarcinogenesis and that the clinical use of carnitine has excellent therapeutic potential in individuals with chronic hepatitis.
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PMID:L-carnitine inhibits hepatocarcinogenesis via protection of mitochondria. 1549 23


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