Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0239946 (liver fibrosis)
 8,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Livers from aryl hydrocarbon receptor-null mice showed a 3-fold increase in retinoids and a 65% decrease in retinoic acid metabolism. Levels of expression of the retinoic acid 4-hydroxylase, P450RAI, did not change, whereas cytochrome P4501A2 levels were lower in the null mouse, as shown earlier; however, this enzyme was found not to be active toward retinoic acid. These data suggest that aryl hydrocarbon receptor controls retinoic acid catabolism, through modulation of an unidentified target gene. Aldehyde dehydrogenases 1 and 2 were down-regulated markedly in the aryl hydrocarbon receptor-deficient mouse liver. 2,3,7,8-Tetrachlorodibenzo-p-dioxin induced cytochrome P4501A2 but not the aldehyde dehydrogenases in wild-type mice, suggesting that aryl hydrocarbon receptor is not involved directly in the down-regulation of this gene. Transglutaminase II, a retinoic acid-responsive gene product, was increased 2-fold, consistent with the liver fibrosis phenotype observed in the null mice. These findings suggest a molecular connection between xenobiotic-activated receptor signaling and retinoid homeostasis.
Cancer Res 1997 Jul 15
PMID:Aryl hydrocarbon receptor knockout mice (AHR-/-) exhibit liver retinoid accumulation and reduced retinoic acid metabolism. 923 Jan 84

The role of thymidine phosphorylase (TP), an angiogenic factor, in hepatocellular carcinoma (HCC) remains unclear. The aim of this study was to clarify the significance of TP in HCC. Thirty-seven patients with HCC, who underwent hepatectomy, were included. The TP activity in both cancerous and non-cancerous parts of livers were measured by an enzyme-linked immunosorbent assay. Another 11 patients without HCC were used to evaluate the TP activity in the non-cancerous parts of livers. Both the cancerous and non-cancerous TP activities were clinico-pathologically investigated with special reference to the multicentric occurrence of HCCs and the degree of liver fibrosis; consisting of normal, fibrosis and cirrhosis. The TP activity in the cancerous part was 94.6 +/- 70.2 U/mg protein, while that in non-cancerous parts of the liver was 80.9 +/- 48.8 U/mg protein. No significant difference was observed. The TP activity in the cancerous part did not correlate with any clinicopathological variables, such as tumor differentiation, portal vein invasion, intrahepatic metastases and prognosis. However, the TP activity in the non-cancerous parts of the liver correlated with the degree of fibrosis (normal/fibrosis/cirrhosis = 34:74:90 U/ mg protein, respectively). Furthermore, regarding the correlation between TP activity in the non-cancerous parts and the simultaneously multicentric occurrence of HCC, the TP activity in the multicentric group (n = 8; 121 U/mg protein) was significantly higher than that in the non-multicentric group (n = 29; 70 U/mg protein). The TP activity in the non-cancerous parts increased in proportion to the degree of liver fibrosis. Furthermore, it is suggested that the higher TP activity in the non-cancerous part is related to the multicentric occurrence of HCCs.
Cancer Lett 2000 Feb 01
PMID:The significance of thymidine phosphorylase activity in hepatocellular carcinoma and chronic diseased livers: a special reference to liver fibrosis and multicentric tumor occurrence. 1069 93

It has become more and more clear in recent decades that the plasminogen activation system, which includes urokinase-type plasminogen activator (uPA), urokinase-type plasminogen activator receptor (uPAR), plasminogen activator inhibitor (PAI)-1 and PAI-2, plays a very important role in the aggressiveness of cancer. Using immunohistochemistry and enzyme-linked immunosorbent assay (ELISA), the expression of these four components of the uPA system was analyzed in 19 cases of hepatocellular carcinoma (HCC) and 18 cases of the adjacent non-cancer tissues which all had chronic active hepatitis with liver fibrosis or liver cirrhosis. Four cases of normal liver tissues, as controls for immunohistochemical stains, were obtained from the hepatectomized liver of patients with metastatic cancer in the liver. The positive rates of uPA, uPAR, PAI-1 and PAI-2 for immunohistochemical stains in cancer tissues were 78.9, 68.4, 57.9 and 31.6%, respectively. Positive signals were mainly distributed in the cytoplasm of the cancer and in stromal cells. Moreover, the strong stains were chiefly located in the invasive front of the cancer cells. No specific stain was detected in four cases of normal liver tissues. In ELISA, there were significant differences between cancer and non-cancer tissues in concentration of uPA, uPAR and PAI-1 (P < 0.0003, 0.0024 and 0.01, respectively), but there was no significant difference in that of PAI-2 (P = 0.37). These results suggest that uPA, uPAR and PAI-1 are related to invasion of HCC.
 ...
PMID:Expression of urokinase-type plasminogen activator, urokinase-type plasminogen activator receptor, and plasminogen activator inhibitor-1 and -2 in hepatocellular carcinoma. 1084 28

An indirect competition immunoassay for the quantification of YKL-40 (cartilage gp-39, Chondrex) in guinea pig serum has been developed using egg yolk antibodies (IgY). The immune response of hens to YKL-40 was verified by immunoblot analyses. Highly specific antibodies were obtained 30 days after the first injection. The ELISA was developed in 96-well microtiter plates with quadruplicate determinations for each point. The assay was based on the ability of YKL-40 present in serum to displace the binding of antibodies to the coated antigen. An inhibition mixture containing standard YKL-40 or guinea pig serum, diluted 1/5, and primary antibodies, diluted 1/5000, was allowed to equilibrate for 2 h at room temperature and dispensed for 16 h at 4 degrees C in wells coated with 1 microg/ml of YKL-40. Detection was achieved by the addition of rabbit anti-chicken antibodies conjugated to peroxidase followed by tetramethylbenzidine. Specificity was assessed by parallelism between a dilution curve of serum and standard YKL-40. The sensitivity of detection was 10 ng/ml. Intra- and interassay coefficients of variation were both 8.7%. The analytical recovery was 101.5+/-5.4% (mean+/-standard deviation (SD), n=9). The YKL-40 concentration in serum from 12 adult guinea pigs was 330+/-216 ng/ml (mean+/-SD) with a lower value of 164 ng/ml and an upper value of 982 ng/ml. In contrast to the rat, a dilution curve of rabbit serum gave parallelism with the guinea pig standard, suggesting recognition of a similar epitope. Possible applications of the assay in the guinea pig include disease models where YKL-40 is overexpressed and could be used as a marker, i.e. osteoarthritis, rheumatoid arthritis, cancer, liver fibrosis, atherosclerosis and more generally, pathologies with increased tissue remodeling.
 ...
PMID:Development of an enzyme-linked immunoassay for the quantification of YKL-40 (cartilage gp-39) in guinea pig serum using hen egg yolk antibodies. 1133 75

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. It is responsible for approximately one million deaths each year, mainly in underdeveloped and developing countries. The aetiological factors identified in the development of HCC included persistent infection by hepatitis B and hepatitis C viruses, and exposure to aflatoxins. Although immunization can protect individuals from being infected by the hepatitis B virus, the early detection of HCC in those who have been infected by the virus remains a challenge. Thus most HCCs present late and are not suitable for curative treatment. Hence there is a tremendous interest and urgency to identify novel HCC diagnostic marker(s) for early detection, and tumour specific disease associated proteins as potential therapeutic targets in the treatment of HCC. Screening for these HCC proteins has been facilitated by proteomics, a key technology in the global analysis of protein expression and understanding gene function. Present and earlier proteome analyses of HCC have used predominantly experimental in vitro systems. The protein expression profiles of several hepatoma cell lines such as HepG2, Huh7, SK-Hep1, and Hep3B have been compared with normal liver, and nontransformed cell lines (Chang and WRL-68), while a comprehensive proteome analysis to create a protein database was carried out for the cell line HCC-M. In the future, proteome analyses utilizing tumour tissues, which reflect the pathological state of HCC more closely, will be undertaken. This work will complement the gene expression studies of HCC which are already underway. Efforts have also been directed at the proteome analysis of hepatic stellate cells, as these cells play an important role in liver fibrosis. Since liver fibrosis is reversible but not cirrhosis, it is of considerable importance to identify therapeutic targets that can slow its progression.
 ...
PMID:Hepatocellular carcinoma: from bedside to proteomics. 1172 36

Pathobiological functions and metabolism of retinoids (vitamin A and its derivatives) in liver fibrosis and hepatocellular carcinoma (HCC) are discussed in the present review. Retinoic acid (RA, active metabolite) exacerbates liver fibrosis that is not accompanied by hepatic necroinflammation, in which RA acts directly on hepatic stellate cells (HSCs); RA enhances plasminogen activator/plasmin levels and thereby induces proteolytic activation of latent transforming growth factor-beta (TGF-beta), a strong fibrogenic cytokine, resulting in enhanced collagen production. We have developed a protease inhibitor, camostat mesilate, that suppresses TGF-beta activation and thereby inhibits the transformation of HSCs, leading to reduced matrix production by the cells. The compound is effective not only in preventing but also in reducing hepatic fibrosis in rats when administered orally. HCC is refractory to RA due to its local depletion in the tumors and also due to malfunction of its nuclear receptor, retinoid X receptor-alpha (RXRalpha) Oral supplementation of a synthetic retinoid named acyclic retinoid led to the disappearance of serum lectin-reactive alpha-fetoprotein (AFP-L3) and subsequently suppressed posttherapeutic recurrence of HCC in cirrhotic patients. These results suggest eradication of AFP-L3-producing latent malignant clones from the liver by the retinoid. We propose the concept of "clonal deletion" therapy for cancer chemoprevention, a new category of cancer chemotherapy.
 ...
PMID:Retinoids in liver fibrosis and cancer. 1177 8

Oltipraz is a cancer chemopreventive agent active against a wide variety of chemical carcinogens. In spite of the intense chemoprevention and toxicology studies on oltipraz, no information is available on its antifibrotic efficacy. In the present study, the effects of oltipraz on dimethylnitrosamine (DMN)-induced liver fibrogenesis were assessed in rats. As part of mechanistic studies, the expression of transforming growth factor-beta1 (TGF-beta1) and tumor necrosis factor-alpha (TNF-alpha) was monitored. Treatment of rats with DMN (10 microl/kg body weight, i.p., three times per week for 4 weeks) resulted in marked increases in plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (gamma-GT) activities. DMN also caused an increase in the plasma bilirubin content, whereas total plasma protein and albumin levels were rather decreased. Oltipraz (50 mg/kg body weight, p.o., three times per week for 4 weeks) inhibited the increases in plasma ALT, AST, gamma-GT and bilirubin by DMN. DMN increased liver fibrosis as histopathologically assessed by Van Gieson's staining and Masson's trichrome staining (fibrosis score, 3.7; Knodell score, 16), which was reduced by oltipraz treatment (fibrosis score, 2.5; Knodell score, 8.0). Reverse transcription-polymerase chain reaction analysis revealed that oltipraz inhibited an increase in the TGF-beta1 mRNA by DMN. Oltipraz was also active in reducing the production of plasma TNF-alpha by DMN or lipopolysaccharide (LPS), which would contribute to its cytoprotective effect. These results demonstrated that oltipraz inhibited hepatocyte injury and impairment of liver function induced by DMN, and reduces DMN-induced liver fibrosis possibly through suppression of TGF-beta1 and TNF-alpha production.
 ...
PMID:Inhibition of dimethylnitrosamine-induced liver fibrosis by [5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione] (oltipraz) in rats: suppression of transforming growth factor-beta1 and tumor necrosis factor-alpha expression. 1180 29

PPAR-gamma belongs to the nuclear hormone receptor superfamily and its ligands include antidiabetic drugs of the thiazolidindione class, and endogenous molecules, including eicosanoids and fatty acids. PPAR-gamma is involved in the pathophysiology of obesity and type II diabetes. More recently, accumulating evidence suggests its role in atherosclerosis, inflammation and cancer. Recent data obtained in cellular models of liver fibrosis indicate that PPAR-gamma activation results in the inhibition of the processes leading to the development of liver fibrosis. These studies identify potential novel therapeutic strategies for the treatment of liver fibrosis.
 ...
PMID:[Thiazolidinediones and PPARgamma system in repair of liver damage]. 1185 Oct 3

Hepatocellular carcinoma is associated with liver fibrosis. Murine schistosomiasis infection offers a model to study hepatic fibrogenesis. Single-stranded phosphorothiate oligodeoxynucleotides containing the TGF-beta regulatory element have been shown to regulate the transcription of this gene and effectively inhibit collagen synthesis in primary fibroblasts isolated from schistosomiasis-induced hepatic granulomas. While the single-stranded oligos did not decrease collagen and non-collagen protein synthesis below control levels, their double-stranded modified and unmodified counterparts did. Competitive cold oligodeoxynucleotide gel mobility shift analysis using control fibroblast nuclear extract demonstrated that the single-stranded oligos diminished binding of the TGF-beta activator protein to the TGF-beta regulatory element while the double-stranded oligos totally inhibited this binding. TGF-beta element containing single-stranded phosphorothioate oligodeoxynucleotides and their double-stranded counterparts may be successful therapeutic agents to inhibit hepatic fibrogenesis and associated hepatocellular carcinoma.
Cancer Lett 2002 Jun 28
PMID:Rational basis for oligodeoxynucleotides to inhibit collagen synthesis in lung fibroblasts and primary fibroblasts from liver granulomas of Schistosoma mansoni-infected mice. 1217 45

Liver fibrosis is a prepathological state wherein damaged liver tissues in chronic liver diseases, such as hepatitis, are not repaired to normal tissues, but converted to fibrous tissue. 5-(2-Pyrazinyl)-4-methyl-1,2-dithiol-3-thione (oltipraz), a cancer chemopreventive agent, is effective against a wide variety of chemical carcinogens. Recently, we reported that oltipraz inhibits liver fibrogenesis (Kang et al., 2002). In the present study, the effects of oltipraz in combination with dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB) on dimethylnitrosamine (DMN)-induced liver fibrogenesis were assessed in rats. Oltipraz (30 mg/kg body weight, p.o., 3 times per week for 4 weeks) was found to inhibit the increases in plasma ALT, AST and bilirubin by DMN, whereas DDB (30 mg/kg body weight, p.o., 3 times per week for 4 weeks) attenuated the increases in the plasma ALT and bilirubin. The lowered plasma protein and albumin contents in DMN-treated rats were completely restored by oltipraz, but not by DDB. DDB decreases liver cell injury and inflammation through inhibition of nuclear factor-kB. DMN increased the accumulation of liver collagen, as indicated by the increase in the 4-hydroxyproline content in liver homogenates, which was reduced by treatment with oltipraz, but not by DDB. Given the differential effect between oltipraz and DDB, the potential enhancement of antifibrotic efficacy by the drugs was assessed in the animal model. Despite the minimal effect of DDB on DMN-induced fibrogenesis, DDB (5-25 mg/kg), administered together with oltipraz (25-5 mg/kg), showed an additive protective effect against hepatotoxicity and fibrosis induced by DMN, which was shown by the blood chemistry parameters and histopathological analysis. The adequate composition ratio of oltipraz to DDB was 5:1. These results provide information on the pharmaceutical composition, comprising of oltipraz and DDB as the active components, for the treatment and/or prevention of liver fibrosis and cirrhosis.
 ...
PMID:The anti-fibrogenic effect of a pharmaceutical composition of [5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione] (oltipraz) and dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethylene dioxybiphenyl-2,2'-dicarboxylate (DDB). 1243 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>