concanavalin-a has been researched along with Liver-Diseases* in 64 studies
2 review(s) available for concanavalin-a and Liver-Diseases
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Role of IL-17 and Th17 cells in liver diseases.
Unbalanced Th1/Th2 T-cell responses in the liver are a characteristic of hepatic inflammation and subsequent liver fibrosis. The recently discovered Th17 cells, a subtype of CD4(+) T-helper cells mainly producing IL-17 and IL-22, have initially been linked to host defense against infections and to autoimmunity. Their preferred differentiation upon TGFβ and IL-6, two cytokines abundantly present in injured liver, makes a contribution of Th17 cells to hepatic inflammation very likely. Indeed, initial studies in humans revealed activated Th17 cells and Th17-related cytokines in various liver diseases. However, functional experiments in mouse models are not fully conclusive at present, and the pathogenic contribution of Th17 cells to liver inflammation might vary upon the disease etiology, for example, between infectious and autoimmune disorders. Understanding the chemokines and chemokine receptors promoting hepatic Th17 cell recruitment (possibly CCR6 or CCR4) might reveal new therapeutic targets interfering with Th17 migration or differentiation in liver disease. Topics: Animals; Autoimmune Diseases; Autoimmunity; Cell Differentiation; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Humans; Infections; Inflammation; Interleukin-17; Interleukin-22; Interleukins; Liver; Liver Diseases; Mice; Receptors, Chemokine; T-Lymphocytes, Regulatory; Th17 Cells; Transforming Growth Factor beta | 2011 |
Immunotoxicology of host-response-mediated experimental liver injury.
Topics: Animals; Autoimmune Diseases; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Galactosamine; Humans; Infections; Lipopolysaccharides; Liver Diseases; Tumor Necrosis Factor-alpha | 1994 |
62 other study(ies) available for concanavalin-a and Liver-Diseases
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Koumine ameliorates concanavalin A-induced autoimmune hepatitis in mice: involvement of the Nrf2, NF-κB pathways, and gut microbiota.
Gelsemiumelegans(Gardner. & Chapm.) Benth. has long been considered a traditional Chinese medicine effective against rheumatoid pain, cancer, cirrhosis, and skin diseases. Koumine (KM), the most abundant alkaloid in G.elegans Benth., demonstrates a variety of biological effects, including antitumor, analgesic, anxiolytic, anti-inflammatory, antidepressant, antioxidant, immunoregulatory, and hepatoprotective effects. Furthermore, the relatively low toxicity of KM makes it a promising drug candidate. This study aimed to investigate the protective effects of KM and its possible mechanisms using a concanavalin A (Con A)-induced autoimmune hepatitis (AIH) model in mice. Mice were orally administered different doses of KM for 14 d before Con A tail vein injections. The effects of KM on serum biochemical markers and liver histopathology were then evaluated 12 h after Con A exposure. The Nrf2 and NF-κB signaling pathways and alterations in gut microbiota were determined using western blotting, immunohistochemistry, and 16S rRNA sequencing to explore the underlying mechanisms of KM exposure. KM pretreatment dose-dependently decreased serum liver injury markers (Alanine aminotransferase, and aspartate aminotransferase) and cytokine levels (Tumor necrosis factor-α and interleukin-6), as well as the liver pathological damage triggered by Con A. Furthermore, the results of the multi-technique analysis indicated that KM activated the Nrf2 pathway, upregulated the expression of anti-oxidation factors HO-1 and Nrf2, and downregulated the expression of Keap1. Moreover, the NF-κB signaling pathway was inhibited. Interestingly, pre-treatment with KM also significantly improved the composition of the gut microbiota probably because it increases the richness of probiotics. Our findings suggest that KM pretreatment could attenuate Con A-induced AIH, the Nrf2 and NF-κB signaling pathways, and that gut microbiota are involved in the process of the hepatoprotective effect. This study provides a theoretical basis for the development of KM as an effective agent against AIH. Topics: Animals; Concanavalin A; Gastrointestinal Microbiome; Hepatitis, Autoimmune; Kelch-Like ECH-Associated Protein 1; Liver; Liver Diseases; Mice; NF-E2-Related Factor 2; NF-kappa B; RNA, Ribosomal, 16S | 2023 |
Hepatocyte-Derived Igκ Exerts a Protective Effect against ConA-Induced Acute Liver Injury.
Immunoglobulin (Igκ) has been reported to be expressed in sorted liver epithelial cells of μMT mice, and the sequence characteristics of hepatocyte-derived Igκ were different from those of classical B-cell-derived Igκ. However, the physiological function of hepatocyte-derived Igκ is still unclear. The expression of Igκ was firstly identified in primary hepatocytes and normal liver cell line (NCTC1469), and hepatocyte-derived Igκ expression was elevated and displayed unique localization in hepatocytes of concanavalin A (ConA)-induced hepatitis model. Moreover, Topics: Animals; Apoptosis; Cell Line; Cells, Cultured; Concanavalin A; Cytoskeleton; Hepatocytes; Immunoglobulin kappa-Chains; Liver Diseases; Male; MAP Kinase Kinase 4; Mice; Mice, Inbred BALB C; Mitochondria; NF-kappa B | 2020 |
The Antidepressant Mirtazapine Inhibits Hepatic Innate Immune Networks to Attenuate Immune-Mediated Liver Injury in Mice.
Activation of the innate immune system, including tissue macrophages and associated neutrophil infiltration, is an important driver of subsequent adaptive immune responses in many autoimmune diseases, including autoimmune hepatitis (AIH). The antidepressant mirtazapine has a unique complex pharmacology, altering signaling through a number of serotonin and histamine receptors that can impact macrophage function; an effect potentially influencing AIH outcome. In the mouse model of concanavalin A (Con A) induced liver injury (mimics many aspects of human AIH), in which early innate immune activation (i.e., stimulated hepatic macrophages/monocytes recruit neutrophils and additional monocytes to the liver) critically drives immune-mediated hepatitis induction, mirtazapine strikingly and dose-dependently inhibited Con A-induced liver injury. This inflammation-suppressing effect of mirtazapine was linked to an attenuation of Con A-stimulated early innate immune responses within the liver, including inhibition of hepatic macrophage/monocyte activation, decreased hepatic macrophage/monocyte-derived pro-inflammatory cytokine (e.g., TNFα) and chemokine (e.g., CXCL1 and CXCL2) production, suppression of Con A-induced increases in the hepatic expression of the neutrophil relevant endothelial cell adhesion molecule ICAM-1, with the resultant significant reduction in neutrophil recruitment into the liver. Consistent with our findings in the Con A model, mirtazapine also significantly reduced activation-induced release of cytokine/chemokine mediators from human CD14 Topics: Animals; Antidepressive Agents; Biomarkers; CD4-Positive T-Lymphocytes; Concanavalin A; Cytokines; Disease Models, Animal; Gene Expression; Immunity, Innate; Immunomodulation; Immunosuppressive Agents; Inflammation Mediators; Liver Diseases; Macrophages; Male; Mice; Mirtazapine; Neutrophil Infiltration; Neutrophils | 2019 |
The hepatoprotective effect of lycopene on Con A-induced liver injury in mice.
Lycopene, the main fat-soluble pigment responsible for the red color of ripe tomatoes, is a symmetrical tetraterpene comprising eight isoprene units. In vitro and in vivo studies have shown that lycopene acts as a potent antioxidant; it is 100 times more effective than vitamin E and 125 times more effective than glutathione as an antioxidant. Here, we divided BALB/c male mice into three equal groups: control, Concanavalin A (Con A), and Con A and lycopene. The control group mice received only vehicle by intraperitoneal injection, the Con A group mice were given Con A, and the Con A and lycopene group mice received Con A and lycopene. The results showed that Con A administration increased histopathological damage, and the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), interleukin (IL)-6, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were increased in serum samples whereas the levels of these compounds were significantly decreased in the Con A and lycopene group compared to the Con A group. Furthermore, we observed that lycopene led to an increase in cell viability and cell growth. The results of this study revealed that lycopene might be a useful hepatoprotective agent for reducing increased proinflammatory cytokine levels, and for increasing cell viability and cell growth. Topics: Alanine Transaminase; Animals; Antioxidants; Aspartate Aminotransferases; Cell Survival; Concanavalin A; Disease Models, Animal; Interferon-gamma; Interleukin-6; Liver Diseases; Lycopene; Male; Mice; Mice, Inbred BALB C; Tumor Necrosis Factor-alpha | 2018 |
Tissue-Specific Regulation of p38α-Mediated Inflammation in Con A-Induced Acute Liver Damage.
Because p38α plays a critical role in inflammation, it has been an attractive target for the development of anti-inflammation therapeutics. However, p38α inhibitors showed side effects, including severe liver toxicity, that often prevailed over the benefits in clinical studies, and the mechanism of toxicity is not clear. In this study, we demonstrate that p38α regulates the inflammatory responses in acute liver inflammation in a tissue-specific manner, and liver toxicity by p38α inhibitors may be a result of the inhibition of protective activity of p38α in the liver. Genetic ablation of p38α in T and NKT cells protected mice from liver injury in Con A-induced liver inflammation, whereas liver-specific deletion of p38α aggravated liver pathology. We found that p38α deficiency in the liver increased the expression of chemokines to recruit more inflammatory cells, indicating that p38α in the liver plays a protective anti-inflammatory role during acute liver inflammation. Therefore, our results suggest that p38α regulates the inflammatory responses in a tissue-specific manner, and that the tissue-specific p38α targeting strategies can be used for the development of an effective anti-inflammation treatment with an improved side-effect profile. Topics: Animals; Concanavalin A; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Gene Knockout Techniques; Immunoblotting; Immunohistochemistry; Inflammation; Inflammation Mediators; Liver; Liver Diseases; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinase 14; Natural Killer T-Cells; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes | 2015 |
Cholestasis induces reversible accumulation of periplakin in mouse liver.
Periplakin (PPL) is a rod-shaped cytolinker protein thought to connect cellular adhesion junctional complexes to cytoskeletal filaments. PPL serves as a structural component of the cornified envelope in the skin and interacts with various types of proteins in cultured cells; its level decreases dramatically during tumorigenic progression in human epithelial tissues. Despite these intriguing observations, the physiological roles of PPL, especially in non-cutaneous tissues, are still largely unknown. Because we observed a marked fluctuation of PPL expression in mouse liver in association with the bile acid receptor farnesoid X receptor (FXR) and cholestasis, we sought to characterize the role of PPL in the liver and determine its contributions to the etiology and pathogenesis of cholestasis.. Time- and context-dependent expression of PPL in various mouse models of hepatic and renal disorders were examined by immunohistochemistry, western blotting, and quantitative real-time polymerase chain reactions.. The hepatic expression of PPL was significantly decreased in Fxr-/- mice. In contrast, the expression was dramatically increased during cholestasis, with massive PPL accumulation observed at the boundaries of hepatocytes in wild-type mice. Interestingly, the hepatic accumulation of PPL resulting from cholestasis was reversible. In addition, similar accumulation of PPL at cellular boundaries was found in epithelial cells around renal tubules upon ureteral obstruction.. PPL may be involved in the temporal accommodation to fluid stasis in different tissues. Further examination of the roles for PPL may lead to the discovery of a novel mechanism for cellular protection by cytolinkers that is applicable to many tissues and in many contexts. Topics: Animals; Cholestasis; Concanavalin A; Epithelial Cells; Gene Expression; Hepatocytes; Kidney Tubules; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Plakins; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; Ureteral Obstruction | 2013 |
Protective effects of lipocalin-2 (LCN2) in acute liver injury suggest a novel function in liver homeostasis.
Lipocalin-2 is expressed under pernicious conditions such as intoxication, infection, inflammation and other forms of cellular stress. Experimental liver injury induces rapid and sustained LCN2 production by injured hepatocytes. However, the precise biological function of LCN2 in liver is still unknown. In this study, LCN2(-/-) mice were exposed to short term application of CCl4, lipopolysaccharide and Concanavalin A, or subjected to bile duct ligation. Subsequent injuries were assessed by liver function analysis, qRT-PCR for chemokine and cytokine expression, liver tissue Western blot, histology and TUNEL assay. Serum LCN2 levels from patients suffering from liver disease were assessed and evaluated. Acute CCl4 intoxication showed increased liver damage in LCN2(-/-) mice indicated by higher levels of aminotransferases, and increased expression of inflammatory cytokines and chemokines such as IL-1β, IL-6, TNF-α and MCP-1/CCL2, resulting in sustained activation of STAT1, STAT3 and JNK pathways. Hepatocytes of LCN2(-/-) mice showed lipid droplet accumulation and increased apoptosis. Hepatocyte apoptosis was confirmed in the Concanavalin A and lipopolysaccharide models. In chronic models (4weeks bile duct ligation or 8weeks CCl4 application), LCN2(-/-) mice showed slightly increased fibrosis compared to controls. Interestingly, serum LCN2 levels in diseased human livers were significantly higher compared to controls, but no differences were observed between cirrhotic and non-cirrhotic patients. Upregulation of LCN2 is a reliable indicator of liver damage and has significant hepato-protective effect in acute liver injury. LCN2 levels provide no correlation to the degree of liver fibrosis but show significant positive correlation to inflammation instead. Topics: Acute Disease; Acute-Phase Proteins; Animals; Apoptosis; Bile Ducts; Blotting, Western; Carbon Tetrachloride; Chemokines; Concanavalin A; Cytokines; Gene Expression; Hepatocytes; Homeostasis; Humans; Immunohistochemistry; Ligation; Lipocalin-2; Lipocalins; Lipopolysaccharides; Liver; Liver Diseases; Mice; Mice, Inbred C57BL; Mice, Knockout; Oncogene Proteins; Proto-Oncogene Proteins; Reverse Transcriptase Polymerase Chain Reaction | 2013 |
In vivo consequences of liver-specific interleukin-22 expression in mice: Implications for human liver disease progression.
Interleukin-22 (IL-22), which acts as either a proinflammatory or anti-inflammatory cytokine in various disease models, is markedly up-regulated in chronic liver diseases, including hepatitis B and C. In this report, we demonstrate a strong correlation between IL-22 expression in the liver with active, inflammatory human liver disease. To clarify the role of IL-22 up-regulation in the pathogenesis of liver diseases, liver-specific IL-22 transgenic (IL-22TG) mice, under the control of albumin promoter, were developed. Despite elevated IL-22 serum levels ranging from 4,000 to 7,000 pg/mL, IL-22TG mice developed normally without obvious adverse phenotypes or evidence of chronic inflammation (except for slightly thicker epidermis and minor inflammation of the skin) compared with wild-type mice. Interestingly, IL-22TG mice were completely resistant to concanavalin A-induced T cell hepatitis with minimal effect on liver inflammation and had accelerated liver regeneration after partial hepatectomy. Although they did not spontaneously develop liver tumors, IL-22TG mice were more susceptible to diethylnitrosamine-induced liver cancer. Microarray analyses revealed that a variety of antioxidant, mitogenic, acute phase genes were up-regulated in the livers of IL-22TG mice compared with those from wild-type mice.. These findings indicate that localized production of IL-22 in the liver promotes hepatocyte survival and proliferation but primes the liver to be more susceptible to tumor development without significantly affecting liver inflammation. Topics: Animals; Cell Survival; Chemical and Drug Induced Liver Injury, Chronic; Concanavalin A; Diethylnitrosamine; Disease Models, Animal; Disease Progression; Hepatectomy; Hepatitis B; Hepatitis C; Humans; Interleukin-22; Interleukins; Liver; Liver Diseases; Liver Neoplasms; Liver Regeneration; Mice; Mice, Inbred C57BL; Mice, Transgenic | 2011 |
Glycogen synthase kinase-3 facilitates con a-induced IFN-γ-- mediated immune hepatic injury.
Immune hepatic injury induced by Con A results primarily from IFN-γ-mediated inflammation, followed by hepatic cell death. Glycogen synthase kinase (GSK)-3, which acts proapoptotically and is proinflammatory, is also important for facilitating IFN-γ signaling. We hypothesized a pathogenic role for GSK-3 in Con A hepatic injury. Con A stimulation caused GSK-3 activation in the livers of C57BL/6 mice. Inhibiting GSK-3 reduced Con A hepatic injury, including hepatic necrosis and apoptosis, inflammation, infiltration of T cells and granulocytes, and deregulated expression of adhesion molecule CD54. Con A induced hepatic injury in an IFN-γ receptor 1-dependent manner. Con A/IFN-γ induced activation and expression of STAT1 in a GSK-3-dependent manner. GSK-3 facilitated IFN-γ-induced inducible NO synthase, but had limited effects on CD95 upregulation and CD95-mediated hepatocyte apoptosis in vitro. Notably, inhibiting GSK-3 decreased Con A-induced IFN-γ production in both wild-type and IFN-γ receptor 1-deficient C57BL/6 mice. In Con A-activated NKT cells, GSK-3 was also activated and was required for nuclear translocation of T-box transcription factor Tbx21, a transcription factor of IFN-γ, but it was not required for CD95 ligand expression or activation-induced cell death. These results demonstrate the dual and indispensable role of GSK-3 in Con A hepatic injury by facilitating IFN-γ-induced hepatopathy. Topics: Animals; Apoptosis; Blotting, Western; Cell Separation; Concanavalin A; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Glycogen Synthase Kinase 3; Hepatocytes; Immunohistochemistry; Interferon-gamma; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Signal Transduction | 2011 |
Genetic delineation of the pathways mediated by bid and JNK in tumor necrosis factor-alpha-induced liver injury in adult and embryonic mice.
Tumor necrosis factor-alpha (TNFalpha)-induced hepatocyte death and liver injury can be mediated by multiple mechanisms, which could be evaluated by different animal models. Previous studies have defined the importance of Bid in mitochondrial apoptosis activation in adult mice treated with lipopolysaccharides in the presence of galactosamine (GalN), which suppresses NF-kappaB activation, but not in embryonic mice in which NF-kappaB activation is suppressed by genetic deletion of p65RelA. JNK has also been found important in TNFalpha-induced mitochondria activation and liver injury in the lipopolysaccharide/GalN and concanavalin A (ConA)/GalN models, but not in a ConA-only model in which NF-kappaB activation was not suppressed. To determine the mechanistic relationship of pathways mediated by Bid and JNK, we investigated these two molecules in TNFalpha injury models that had not been previously examined. Most importantly, we created and studied mice deficient in both Bid and JNK. We found that, like JNK, Bid was also required for TNFalpha-induced injury induced by concanavalin A/GalN but not by ConA alone. Furthermore, our results indicate that these two molecules function in a largely overlapped manner, with Bid being downstream of JNK in the adult livers. However, JNK, but not Bid, was able to contribute to the TNFalpha-induced liver apoptosis in RelA-deficient embryos. The Bid-independent role of JNK was also observed in the adult mice, mainly in the promotion of the lethal progression of the TNFalpha injury. This work defined both linear and parallel relationships of Bid and JNK in TNFalpha-induced hepatocyte apoptosis and liver injury. Topics: Animals; Apoptosis; BH3 Interacting Domain Death Agonist Protein; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Embryo, Mammalian; Galactosamine; Hepatocytes; Lipopolysaccharides; Liver; Liver Diseases; MAP Kinase Kinase 4; Mice; Mice, Knockout; Mitochondria, Liver; Mitogens; Transcription Factor RelA; Tumor Necrosis Factor-alpha | 2009 |
Rapamycin prevents concanavalin A-induced liver injury by inhibiting lymphocyte activation.
Liver injury induced by concanavalin A (Con A) is often used as a model to study the pathophysiology of immune mediated liver injury. Rapamycin (Rapa) is an effective immunosuppressant widely used for preventing immune activation and transplant rejection. However, the effect of Rapa on liver injury caused by Con A has not been carefully examined. In the present study, we examined the effect of Rapa on liver injury caused by Con A.. Mice received intraperitoneal Rapa injection before Con A intravenous administration. The liver injury was examined by measuring serum transaminase and pathology, and the level of cytokines was detected by enzyme linked immunosorbent assay (ELISA).. In the present study, we examined the effect of Rapa on liver injury after Con A injection in mice. We found that the treatment of mice with Rapa protected the liver from Con A-induced injury. Pretreatment with Rapa dramatically ameliorated Con A-induced mortality. This protection was associated with reduced transaminase levels in the blood and further confirmed by liver histology. ELISA showed that Rapa suppressed pro-inflammatory cytokines IFN-gamma and TNF-alpha production as compared with the untreated controls. Furthermore, intrahepatic lymphocyte proliferation was significantly inhibited.. These findings suggested that Rapa has the therapeutic potential for treatment of immune-mediated liver injury in the clinic. Topics: Animals; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytoprotection; Disease Models, Animal; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Immunosuppressive Agents; Inflammation Mediators; Injections, Intraperitoneal; Interferon-gamma; Interleukin-4; Liver; Liver Diseases; Lymphocyte Activation; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Sirolimus; Time Factors; Transaminases; Tumor Necrosis Factor-alpha | 2009 |
Decreased STAT-1 phosphorylation by a thio analogue of beta-D-glucosylceramide is associated with altered NKT lymphocyte polarization.
Glycolipid presentation to natural killer T (NKT) lymphocytes by CD1 proteins is important for antigen recognition. It was recently suggested that beta-glycolipids exert an immune-modulatory effect on NKT lymphocytes, alleviating immune-mediated disorders. The current study aimed to determine the effect of ligand structure on intrahepatic NKT lymphocyte function in concanavalin A (ConA) hepatitis, an NKT-mediated disorder. C57BL/6 mice were injected with a non-degradable beta-D-glucosylceramide containing a thioglycosidic bond (GCT), beta-D-glucosylceramide (GC), or vehicle. The phosphorylation of STAT-1, intrahepatic NKT lymphocyte number, and serum IFN-gamma levels were determined. Liver damage was assessed by serum transaminases and the degree of apoptosis. The administration of GCT led to a significant inhibitory effect on intrahepatic NKT lymphocytes. Both GCT and GC led to a decrease in STAT-1 phosphorylation and a decrease in IFN-gamma serum levels. These effects were associated with the alleviation of ConA immune-mediated hepatitis, as determined by a similar substantial decrease in serum transaminases and a profound decrease in apoptosis as noted by TUNEL assay, and were NKT-type I dependent.. Alteration of the chemical structure of the GC by replacing the O-glycosidic bond with an S-glycosidic bond results in a non-degradable molecule GCT and significantly suppresses intrahepatic NKT lymphocytes. These results suggest that cellular events that alter the enzymatic pathways of glycosylceramides serve as an initial stimulus for NKT cell polarization in vivo. Topics: Animals; Antigens, CD1; Apoptosis; Cell Polarity; Concanavalin A; Flow Cytometry; Glucosylceramides; Interferon-gamma; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Phosphorylation; Spleen; STAT1 Transcription Factor | 2009 |
Differential roles of JNK in ConA/GalN and ConA-induced liver injury in mice.
Tumor necrosis factor-alpha-mediated liver injury can be induced by several different means; however, the signaling events and mechanisms of cell death are likely different. We investigated the mechanism of both apoptotic and necrotic hepatocyte cell death as well as the role of c-Jun NH2-terminal kinase (JNK) in the ConA and ConA/D-galactosamine (GalN) models of murine liver injury. ConA alone induced primarily necrotic cell death with no caspase activation, whereas ConA/GalN induced apoptosis in addition to necrotic cell death. The bi-modal death pattern in the ConA/GalN model was confirmed by the use of transgenic mice expressing a dominant-negative form of Fas-associated death domain in which the mice were resistant to apoptotic but not necrotic cell death. JNK1 and, more significantly, JNK2 participated in the induction of hepatocyte apoptosis in response to ConA/GalN. Deletion of JNK led to the stabilization of FLIP L, reduced caspase-8 activation, decreased Bid cleavage, and inhibition of the mitochondrial apoptosis pathway. In contrast, JNK did not participate in necrotic death induced by ConA either alone or in combination with GalN. As such, JNK-deficient mice remained susceptible to necrotic liver injury in both model systems. Thus, ConA and ConA/GalN mouse models induce liver injury with different mechanisms of cell death, and JNK contributes to apoptotic but not necrotic cell death. These findings further elucidate the specific pathways involved in tumor necrosis factor-alpha-mediated liver injury. Topics: Animals; Apoptosis; BH3 Interacting Domain Death Agonist Protein; Caspase 8; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Enzyme Activation; Fas-Associated Death Domain Protein; Galactosamine; Gene Deletion; JNK Mitogen-Activated Protein Kinases; Liver Diseases; Mice; Mice, Inbred C57BL; Mitochondria, Liver; Mutant Proteins; Necrosis; Phosphorylation | 2008 |
[Effect of ronggan mixture on cell apoptosis in rats with chronic immune liver injury induced by concanavalin A].
To explore the effects of Ronggan Mixture (RGM) on cell apoptosis by observing the expressions of apoptosis-related genes (Fasl and Bcl-2) in transgenic mice with chronic liver immune injury induced by concanavalin A (ConA).. Seventy-four transgenic mice were divided into 6 groups, the model group, the normal group, and the treated groups treated respectively with biphenyldicarboxylate (DDB), oriental wormwood (OWW), Yinchenhao Decoction (YCHD) and RGM. Pathologic changes of liver tissue were observed by light microscopy, number of apoptotic cells were determined by TUNEL method, and expressions of apoptosis-related genes, Fasl and Bcl-2, in hepatic T lymphocyte were detected by flow cytometer.. Evident pathological changes of liver appeared in the model mice, showed severely destroyed structure of hepatic lobules. As compared with the model group, the changes of liver fibrosis and cell necrosis were much lessened in the RGM group and the YCHD group (P < 0.05). The protein expression of apoptotic gene Fasl and the apoptotic index in the model group were higher than those in the normal group (P < 0.05), but that of the apoptotic inhibiting gene, Bcl-2, in model mice was similar to that in normal mice. As compared with the model group, apoptosis index decreased (P < 0.01), levels of Fasl expression was lower and Bcl-2 expression was higher in the RGM group and the YCHD group (P < 0.05, P < 0.01), and the effect of the two was similar, but significantly superior to that of OWW and DDB (P < 0.05 or P < 0.01).. The Chinese compound, RGM and YCHD can not only relieve the hepatic pathological injury, but also reduce the cell apoptosis in chronic liver immune injury mice through regulating the expressions of Fasl and Bcl-2. Topics: Animals; Apoptosis; Concanavalin A; Disease Models, Animal; Drugs, Chinese Herbal; Fas Ligand Protein; Female; Gene Expression; Liver; Liver Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Proto-Oncogene Proteins c-bcl-2; Random Allocation | 2008 |
Ursodeoxycholic acid protects concanavalin A-induced mouse liver injury through inhibition of intrahepatic tumor necrosis factor-alpha and macrophage inflammatory protein-2 production.
Ursodeoxycholic acid (UDCA) is widely used for the therapy of liver dysfunction. In this study, we investigated the protective effect of UDCA in concanavalin A-induced mouse liver injury. The treatment with UDCA at oral doses of 50 and 150 mg/kg at 2 h before concanavalin A injection significantly reduced the elevated plasma levels of aminotransferases and the incidence of liver necrosis compared with concanavalin A-injected control group without affecting the concentrations of liver hydrophobic bile acids. UDCA significantly inhibited elevated levels of tumor necrosis factor-alpha (TNF-alpha), macrophage inflammatory protein-2 (MIP-2), and interleukin 6 (IL-6) in blood of concanavalin A-injected mice. To clarify the influence of UDCA on production of cytokines, we examined intrahepatic mRNA expressions and the protein levels of TNF-alpha, MIP-2, interferon-gamma (IFN-gamma), IL-4, IL-6, and IL-10 at 1 h after concanavalin A injection. The treatment with UDCA significantly decreased the intrahepatic levels of TNF- alpha and MIP-2, whereas this compound showed no clear effect on IFN-gamma, IL-4, IL-6, or IL-10. Furthermore, UDCA significantly decreased myeloperoxidase activity as well as MIP-2 level in the liver and histological examination of liver tissue revealed that intrasinusoidal accumulation of neutrophils was decreased markedly by UDCA. In addition, UDCA significantly inhibited the production of TNF-alpha and MIP-2 when cultured with nonparenchymal and lymph node cells. In conclusion, these findings suggest that UDCA protects concanavalin A-induced liver injury in mice by inhibiting intrahepatic productions of TNF-alpha and MIP-2, and the infiltration of neutrophils into the liver. Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokine CXCL2; Cholagogues and Choleretics; Concanavalin A; Dose-Response Relationship, Drug; Gene Expression Regulation; Interferon-gamma; Interleukins; Liver; Liver Diseases; Male; Mice; Mice, Inbred BALB C; Neutrophil Infiltration; RNA, Messenger; Tumor Necrosis Factor-alpha; Ursodeoxycholic Acid | 2008 |
Superiority of serum type-I arginase and ornithine carbamyltransferase in the detection of toxicant-induced acute hepatic injury in rats.
Despite the restricted distribution to mitochondria of hepatocytes in the periportal region, ornithine carbamyltransferase (OCT) have been suggested to be a sensitive marker in addition to type-I arginase (ARG), even in centrilobular damage of the liver. We attempted to confirm the universal advantages of ARG and OCT in the evaluation of hepatotoxicity induced by toxicants, and to clarify whether the character of a marker is a more important factor than its localization in its clinical superiority.. Rats were administered carbon tetrachloride, allyl alcohol, D-galactosamine, lipopolysaccharide, and concanavalin A and the course of damage was monitored by serum ARG and OCT, together with alanine aminotransferase (ALT) and aspartate aminotransferase (AST).. The significant increase in the serum levels of the markers was faster in ARG and OCT than AST and ALT. Further, the extent of the increase at the peak was always higher in ARG and OCT than in AST and ALT.. The superiority of ARG and OCT over AST and ALT in the detection of hepatotoxicity seems universal, at least in toxicant-induced acute liver injuries. The apparent faster appearance of mitochondria-derived enzyme, OCT, in serum than cytosol-derived enzyme, ALT, shows that leakage into the circulation is dependent on the marker rather than its localization. Topics: Alanine Transaminase; Animals; Arginase; Aspartate Aminotransferases; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Concanavalin A; Galactosamine; Lipopolysaccharides; Liver Diseases; Liver Function Tests; Male; Ornithine Carbamoyltransferase; Propanols; Rats; Rats, Wistar | 2008 |
Enhanced susceptibility to Con A-induced liver injury in mice transgenic for the intracellular isoform of human TNF receptor type 2.
TNF is a pleiotropic cytokine involved in a variety of inflammatory processes and immune responses. TNF effects are mediated via two distinct membrane receptors: TNFR1 and TNFR2. Investigations concerning regulation and function of TNFR2 revealed a novel TNFR2 isoform in human and mouse cells, termed icp75TNFR, with mainly intracellular localization. As human icp75TNFR is capable of functional interaction with mouse TNF, mouse lines transgenic for the human icp75TNFR were generated and characterized. Transgenic expression was identified in several organs, and soluble human (sh)TNFR2 was detected in serum. shTNFR2 released from transfected cells or peritoneal macrophages of transgenic mice protected from TNF-induced cytotoxicity. Although in vivo, no change in inflammatory reactions was observed in models of septic peritonitis, of colitis, or after stimulation with bacterial LPS, liver injury was strongly enhanced in transgenic mice after Con A challenge. Thus, the functional properties of human icp75TNFR seem to be similar to that of TNFR2, resulting in exacerbation of inflammatory tissue damage, thus revealing the functional importance of TNFR2 in pathophysiological processes. Topics: Animals; Cell Death; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Susceptibility; Galactosamine; Humans; Intracellular Space; Lipopolysaccharides; Liver Diseases; Mice; Mice, Transgenic; Neutralization Tests; Protein Isoforms; Receptors, Tumor Necrosis Factor, Type II; Solubility; Tumor Necrosis Factor-alpha | 2008 |
Short-form Ron receptor is required for normal IFN-gamma production in concanavalin A-induced acute liver injury.
Abrogation of Ron receptor tyrosine kinase function results in defects in macrophage activation and dysregulated acute inflammatory responses in vivo. Several naturally occurring constitutively active alternative forms of Ron have been identified, including from primary human tumors and tumor cell lines. One of these alternative forms, short-form (SF) Ron, is generated from an alternative start site in intron 10 of the Ron gene that eliminates most of the extracellular portion of the receptor and is overexpressed in several human cancers. To test the physiological significance of SF-Ron in vivo, mice were generated that solely express the full-length form of Ron (FL-Ron). Our results show that elimination of the capacity to express SF-Ron in vivo leads to augmented production of IFN-gamma from splenocytes following stimulation ex vivo with either concanavalin A or anti-CD3/T cell receptor monoclonal antibody. Moreover, in a concanavalin A-induced murine model of acute liver injury, FL-Ron mice have increased production of serum INF-gamma and serum alanine aminotransferase levels and worsened liver histology and overall survival compared with wild-type control mice. Taken together, these results suggest for the first time that SF-Ron impacts the progression of inflammatory immune responses in vivo and further support a role for the Ron receptor and its various forms in liver pathophysiology. Topics: Animals; Base Sequence; Chemical and Drug Induced Liver Injury; Concanavalin A; DNA Primers; DNA, Complementary; Gene Expression Regulation; Genetic Vectors; Interferon-gamma; Liver; Liver Diseases; Mice; Receptor Protein-Tyrosine Kinases; Restriction Mapping; Reverse Transcriptase Polymerase Chain Reaction; RNA; Spleen; T-Lymphocytes | 2007 |
Prostaglandin I(2) and E(2) mediate the protective effects of cyclooxygenase-2 in a mouse model of immune-mediated liver injury.
Studies of the molecular and cellular mechanisms of concanavalin A (ConA)-induced liver injury have provided important knowledge on the pathogenesis of many liver diseases involving hepatic inflammation. However, studies identifying hepato-protective factors based on the mechanistic understanding of this model are lacking. Evidence suggests that certain prostaglandin (PG) products of cyclooxygenase (COX)-1 and COX-2 provide important anti-inflammatory and cytoprotective functions in some pathophysiological states. In the present study, we demonstrate a protective role of COX-2 derived PGs in ConA-induced liver injury. COX-2(-/-) mice developed much more severe liver damage upon ConA treatment compared with wild-type and COX-1(-/-) mice. Treatment of COX-2(-/-) mice with misoprostol (a PGE(1/2) analog) or beraprost (a PGI(2) analog) significantly decreased ConA-induced liver injury. Data from both in vivo and in vitro experiments demonstrated that misoprostol and beraprost acted directly on hepatic leukocytes, including natural killer (NK)T and T cells, and down-regulated their production of interferon (IFN)-gamma, which are critical in mediating ConA-induced tissue damage. Collectively, the results provide strong evidence that the protective effects of COX-2 within the liver are mediated through the production of PGE(2) and PGI(2), which exert anti-inflammatory functions. These findings suggest that COX-2-derived PGs may have great therapeutic potentials in treating patients with inflammatory liver diseases. Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Down-Regulation; Epoprostenol; Gene Expression Regulation; Gene Expression Regulation, Enzymologic; Inflammation; Interferon-gamma; Liver Diseases; Male; Mice; Mice, Knockout; Misoprostol; Mitogens | 2007 |
The protective action of scutellarin against immunological liver injury induced by concanavalin A and its effect on pro-inflammatory cytokines in mice.
Scutellarin is a natural compound from a Chinese herb. The purpose of this paper was to study the protective effect of scutellarin on concanavalin A (Con A)-induced immunological liver injury and its effect on liver nuclear factor kappaB (NF-kappaB), tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and inducible nitric oxide synthase (iNOS) expression in mice. Mouse liver injury was produced by injection of Con A 25 mg kg-1 via the tail vein. Scutellarin 50 or 100 mg kg-1 was peritoneally administered to mice 9 or 1 h before injection of Con A. The levels of serum alanine aminotransferase (ALT) and asparatate aminotransferase (AST), NO2-/NO3- and TNF-alpha were determined with biochemical kits, and ELISA using Quantikine Mouse TNF-alpha kit according the manufacturer's instructions. Liver lesions were examined by light microscope. The expression of TNF-alpha, IFN-gamma, iNOS and Fas mRNA in the livers was detected by RT-PCR; and the expression of c-Fos, c-Jun, iNOS and IkappaB proteins was measured by Western Blotting. As a result, pretreatment with scutellarin 100 mg kg-1 significantly decreased the serum ALT, AST, NO2-/NO3- and TNF-alpha levels, and also reduced liver lesions induced by Con A. Scutellarin 100 mg kg-1 down-regulated expression of TNF-alpha and iNOS mRNA, and c-Fos, c-Jun and iNOS protein, while scutellarin enhanced the degradation of IkappaB in the livers of mice injected with Con A. The results suggest that scutellarin has a protective action against Con A-induced liver injury in mice, and its active mechanism may be related to the inhibition of the NF-kappaB-TNF-alpha-iNOS transduction pathway. Topics: Alanine Transaminase; Animals; Apigenin; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; fas Receptor; Genes, fos; Genes, jun; Glucuronates; I-kappa B Proteins; Interferon-gamma; Liver Diseases; Male; Mice; Mice, Inbred ICR; NF-kappa B; NF-KappaB Inhibitor alpha; Nitrates; Nitric Oxide Synthase Type II; Nitrites; Protective Agents; RNA, Messenger; Tumor Necrosis Factor-alpha | 2007 |
[The protective role of adiponectin in Con A-induced mouse liver injury].
To evaluate the role of adiponectin in regulating tumor necrosis factor alpha (TNF alpha) production and preventing fulminant autoimmunological damage of hepatocytes following concanavalin A (Con A) injection into mice.. Three days after recombinant plasmids pAA-neo-mAd were injected into the mice via the tail veins, Con A was injected into the mice. Mice transfected with empty pAA-neo vector served as controls. The serum levels of alanine aminotransferase (ALT), TNF alpha and adiponectin were detected, and histological examination of livers was carried out at different time points after the Con A injection. All results were subjected to statistical analyses.. Histological examinations showed that the damage in livers of mice with high serum adiponectin levels was milder than that of the controls. The serum levels of ALT and TNF alpha were both lower than those of the controls (P less than 0.01, respectively). Statistical analyses showed the serum levels of ALT was negatively related to the levels of adiponectin in the sera (r=-0.5034).. Adiponectin is effective in protecting hepatocytes from Con A-induced immunological injury. The mechanism of this protective effect may be caused by inhibiting the synthesis and/or release of TNF alpha. Topics: Adiponectin; Alanine Transaminase; Animals; Concanavalin A; Female; Immune System Diseases; Liver; Liver Diseases; Mice; Mice, Inbred BALB C; Tumor Necrosis Factor-alpha | 2007 |
Applicability of alpha-fetoprotein-concanavalin A (AFP-ConA) binding to discriminate between germinal or hepatic origin of AFP in germ cell tumour patients during chemotherapy or follow-up.
Topics: alpha-Fetoproteins; Chromatography, Agarose; Concanavalin A; Humans; Liver Diseases; Neoplasms, Germ Cell and Embryonal | 2007 |
Prevention of hepatic injury by a traditional Chinese formulation, BJ-JN, in mice treated with Bacille-Calmette-Guérin and lipopolysaccharide.
The hepatoprotective effects of BJ-JN (a traditional Chinese formulation) were evaluated in Bacille-Calmette-Guérin and lipopolysaccharide (BCG/LPS)-induced immunological liver injury (ILI) in mice. BJ-JN (0.75, 1.5, 3 g/kg) was administered via gavage daily for 10 days. Liver index (liver weight/body weight), serum levels of alanine aminotransferase (ALT), hepatic nitric oxide (NO), malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, splenocyte proliferation, production of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) by peritoneal macrophages, and histopathologic changes of the liver were evaluated following the 10 days treatment. BJ-JN (0.75, 1.5, 3 g/kg) effectively reduced the BCG/LPS-induced elevated liver index, serum ALT levels, hepatic NO and MDA content, and restored hepatic SOD activity in ILI mice. BJ-JN treatment also alleviated diminished splenocyte proliferation induced by concanavalin A (ConA) and repressed abnormally high levels of TNF-alpha and IL-1 from peritoneal macrophages. The histopathological analysis suggested that BJ-JN reduced the degree of liver injury of ILI mice. These results suggest that BJ-JN has a protective and therapeutic effect on ILI mice, which might be associated with its antioxidant properties, ability to reduce NO production and immunoregulatory function. Topics: Alanine Transaminase; Animals; Antioxidants; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Interleukin-1; Lipopolysaccharides; Liver; Liver Diseases; Lymphocyte Activation; Macrophages, Peritoneal; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; Mycobacterium bovis; Nitric Oxide; Spleen; Superoxide Dismutase; Tumor Necrosis Factor-alpha | 2006 |
Constitutive androstane receptor (CAR) ligand, TCPOBOP, attenuates Fas-induced murine liver injury by altering Bcl-2 proteins.
The constitutive androstane receptor (CAR) modulates xeno- and endobiotic hepatotoxicity by regulating detoxification pathways. Whether activation of CAR may also protect against liver injury by directly blocking apoptosis is unknown. To address this question, CAR wild-type (CAR+/+) and CAR knockout (CAR-/-) mice were treated with the CAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) and then with the Fas agonist Jo2 or with concanavalin A (ConA). Following the administration of Jo2, hepatocyte apoptosis, liver injury, and animal fatalities were abated in TCPOBOP-treated CAR+/+ but not in CAR-/- mice. Likewise, acute and chronic ConA-mediated liver injury and fibrosis were also reduced in wild-type versus CAR(-/-) TCPOBOP-treated mice. The proapoptotic proteins Bak (Bcl-2 antagonistic killer) and Bax (Bcl-2-associated X protein) were depleted in livers from TCPOBOP-treated CAR+/+ mice. In contrast, mRNA expression of the antiapoptotic effector myeloid cell leukemia factor-1 (Mcl-1) was increased fourfold. Mcl-1 promoter activity was increased by transfection with CAR and administration of TCPOBOP in hepatoma cells, consistent with a direct CAR effect on Mcl-1 transcription. Indeed, site-directed mutagenesis of a putative CAR consensus binding sequence on the Mcl-1 promoter decreased Mcl-1 promoter activity. Mcl-1 transgenic animals demonstrated little to no acute liver injury after administration of Jo2, signifying Mcl-1 cytoprotection. In conclusion, these observations support a prominent role for CAR cytoprotection against Fas-mediated hepatocyte injury via a mechanism involving upregulation of Mcl-1 and, likely, downregulation of Bax and Bak. Topics: Animals; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Chemical and Drug Induced Liver Injury; Concanavalin A; Constitutive Androstane Receptor; DNA; fas Receptor; Gene Expression; Hepatocytes; Immunohistochemistry; Liver Diseases; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Microscopy, Electron; Mutation; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins; Polymerase Chain Reaction; Proto-Oncogene Proteins c-bcl-2; Pyridines; Receptors, Cytoplasmic and Nuclear; Transcription Factors | 2006 |
Effect of 2-amino-2-(2-(4-octylphenyl) ethyl) propane-1,3-diol hydrochloride (FTY 720) on immune liver injury in mice.
To investigate the protective effect against two immune liver injury models in mice by 2-amino-2-(2-(4-octylphenyl) ethyl) propane-1,3-diol hydrochloride and its possible mechanisms in Con A-induced liver damage.. Liver tissue or hepatocyte injury was monitored biochemically by measuring alanine aminotransferase (sALT) and aspartate aminotransferase (sAST) activity. Hematoxylin and eosin (HE) staining was used for histopathological examination. To evaluate the role of IFN-gamma and IL-4 in the liver injury, serum levels of IFN-gamma and IL-4 were determined using commercially available ELISA kit at 12 h after Con A challenge. We also determined FTY 720-induced spleen cell apoptosis by flow cytometry analysis or spleen cell proliferation test.. Different doses of FTY 720 treatment dramatically reduced circulating markers of hepatocyte injury in two kinds of immunological liver injury models. FTY 720 dramatically reduced the elevated serum IFN-gamma and IL-4 levels after Con A injection. Effect of spleen cell supernatants treated with Con A or FTY 720 on hepatocytes showed that ALT activities in cultured hepatocyte supernatants in Con A treatment group increased markedly and FTY 720 could reduce this elevated ALT activities in FTY 720 treatment group. FTY 720 dose-dependently increased the percentage of apoptotic cells in T cells and inhibited splenocyte proliferation induced by Con A.. Pretreatment with FTY 720 was shown to produce protective effect on the immune liver injury in mice. The possible mechanism of FTY 720 on Con A-induced liver damage is that it could inhibit lymphocyte proliferation and induce lymphocyte apoptosis, resulting in the reduction of IL-4 or IFN-gamma release, and subsequently protecting liver from being damaged by Con A. Topics: Acute Disease; Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Cell Division; Concanavalin A; Fingolimod Hydrochloride; Hepatocytes; Immunosuppressive Agents; Interferon-gamma; Interleukin-4; Lipopolysaccharides; Liver Diseases; Male; Mice; Mycobacterium bovis; Propylene Glycols; Rats; Rats, Wistar; Sphingosine; Spleen | 2005 |
Liver protection by bis(maltolato)zinc(II) complex.
The aim of this study was to perform screening of a novel drug for treating liver injury. Bis(maltolato)zinc(II) complex [Zn(Mal)(2)], which was previously reported to possess insulinomimetic activity, was found to have potency against experimentally induced liver injury both in vitro and in vivo. Cultured rat hepatocytes were treated with bromobenzene for 24 h to induce cellular injury. Zn(Mal)(2) of various concentrations was added along with bromobenzene in order to evaluate the hepatoprotective activity of Zn(Mal)(2) in vitro. The number of viable hepatocytes decreased by 42% in the culture with bromobenzene. However, hepatocyte viability was maintained when Zn(Mal)(2) was added to the bromobenzene culture. The hepatoprotective activity of Zn(Mal)(2) in vivo was investigated using a concanavalin A-induced liver injury model in BALB/c mice. Changes in serum aminotransferase activities and the secretion of several cytokines were measured. The hepatoprotective effect of Zn(Mal)(2) was also demonstrated in vivo by the suppression of serum aspartate aminotransferase and alanine aminotransferase elevation. No significant changes in serum cytokines associated with the induction of hepatic damage were observed in the concanavalin A-induced injury model. However, examination of concanavalin A-treated mouse splenocytes revealed a dose-dependent suppression of cytokine secretions by Zn(Mal)(2). Zn(Mal)(2) possessed hepatoprotective activity and might exert its effect by a number of mechanisms. Topics: Animals; Bromobenzenes; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Liver Diseases; Mice; Mice, Inbred BALB C; Organometallic Compounds; Rats; Transaminases | 2004 |
High, but not low, molecular weight hyaluronan prevents T-cell-mediated liver injury by reducing proinflammatory cytokines in mice.
The extracellular matrix component hyaluronan (HA) modulates the production of various cytokines and chemokines by activated inflammatory cells. In this study, we investigated whether exogenous administration of HA influences T-cell-mediated liver injury and cytokine production.. Liver injury was induced by administration of concanavalin A (Con A) or D-galactosamine/lipopolysaccharide (GalN/LPS), and 0.05%-0.35% (v/v) HA (MW 250, 470, 780, 900, and 1200 kDa) was administered intravenously 18 h before Con A or GalN/LPS injection. Plasma ALT level was determined enzymatically and plasma cytokine levels were determined by ELISA.. The elevated plasma levels of ALT at 8 h after Con A and at 7 h after GalN/LPS injection were significantly decreased by pretreatment with high molecular weight HAs (780, 900, and 1200 kDa) but not low molecular weight HAs (250 and 470 kDa). High molecular weight HA (900 kDa) significantly reduced plasma tumor necrosis factor-alpha, interferon gamma, macrophage inflammatory protein 2, and interleukin 4 levels after Con A injection. However, this inhibitory effect on plasma cytokines was not observed with low molecular weight HA (250 kDa) pretreatment.. The present results suggest that high molecular weight but not low molecular weight HA prevents liver injury by reducing proinflammatory cytokines in a T-cell-mediated liver injury model. The extracellular matrix component hyaluronan (HA) modulates the production of various cytokines and chemokines by activated inflammatory cells. In this study, we investigated whether exogenous administration of HA influences T-cell-mediated liver injury and cytokine production. Topics: Adjuvants, Immunologic; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Galactosamine; Hyaluronic Acid; Infusions, Intravenous; Lipopolysaccharides; Liver Diseases; Male; Mice; Models, Animal; Molecular Weight; T-Lymphocytes | 2004 |
A recombinant adenovirus encoding hepatitis C virus core and E1 proteins protects mice against cytokine-induced liver damage.
Hepatitis C virus (HCV) infection has a strong tendency to evolve to chronicity despite up-regulation of proapoptotic cytokines in the inflamed liver. The mechanisms responsible for persistent viral replication in this inflammatory environment are obscure. It is conceivable that viral replication would be facilitated if the infected hepatocytes are rendered resistant to cytokine-induced cytotoxicity. In this study, we investigated if an adenovirus encoding HCV core and E1 (RAdCE1) could reduce liver cell injury in different in vivo models of cytokine-mediated hepatotoxicity in mice. We show that RAdCE1 markedly attenuates hepatocellular apoptosis and the increase in serum transaminase levels after concanavalin A (con A) challenge. This protective effect is accompanied by an inhibition of nuclear translocation of nuclear factor kappaB (NF-kappaB); reduced expression of inducible nitric oxide synthase (iNOS); decreased hepatic messenger RNA levels of chemokines macrophage inflammatory protein 2 (MIP-2), monocyte chemoattractant protein 1 (MCP-1), and interferon-inducible protein 10 (IP-10); and abrogation of liver leukocyte infiltration. RAdCE1 also causes a reduction in serum transaminase levels and inhibits hepatocellular apoptosis in mice given tumor necrosis factor (TNF)-alpha plus D-galactosamine. In conclusion, HCV structural antigens can protect liver cells against the proapoptotic effects of proinflammatory cytokines. The antiapoptotic status of infected liver cells may represent a mechanism favoring viral persistence. Our findings also suggest that, in chronic hepatitis C, the burden of hepatocellular damage mainly affects noninfected liver cells. Topics: Acute Disease; Adenoviridae; Animals; Cell Nucleus; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Drug Combinations; Female; Galactosamine; Gene Expression; Hepacivirus; Liver Diseases; Mice; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Recombination, Genetic; Transduction, Genetic; Tumor Necrosis Factor-alpha; Viral Core Proteins; Viral Envelope Proteins | 2003 |
Silibinin protects mice from T cell-dependent liver injury.
Silibinin is the major pharmacologically active compound of the Silybum marianum fruit extract silymarin. Its well-known hepatoprotective activities are mostly explained by antioxidative properties, inhibition of phosphatidylcholine synthesis or stimulation of hepatic RNA and protein synthesis. Here, we characterized the hepatoprotective potential of silibinin as an immune-response modifier in T cell-dependent hepatitis in vivo.. Silibinin was tested in the mouse model of concanavalin A (ConA)-induced, T cell-dependent hepatitis. Liver injury was assessed by quantification of plasma transaminase activities and intrahepatic DNA fragmentation. Plasma cytokine concentrations were determined by enzyme-linked immunosorbent assay (ELISA), intrahepatic cytokine and inducible NO synthase (iNOS) mRNA levels by reverse transcriptase polymerase chain reaction, intrahepatic iNOS expression by immunofluorescent staining, and intrahepatic nuclear factor kappa B (NF-kappaB) activation by electrophoretic mobility shift assay.. Silibinin significantly inhibited ConA-induced liver disease. Silibinin proved to be an immune-response modifier in vivo, inhibiting intrahepatic expression of tumor necrosis factor, interferon-gamma, interleukin (IL)-4, IL-2, and iNOS, and augmenting synthesis of IL-10. In addition, silibinin inhibited intrahepatic activation of NF-kappaB.. Silibinin, suppressing T cell-dependent liver injury as an immune-response modifier, might be a valuable drug in therapeutic situations in which intrahepatic immunosuppression is required. Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Cytoprotection; Enzyme Induction; Galactosamine; Leukocytes; Liver; Liver Diseases; Male; Mice; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Recombinant Proteins; RNA, Messenger; Silybin; Silymarin; T-Lymphocytes; Tumor Necrosis Factor-alpha | 2003 |
In vivo regulation of inducible no synthase in immune-mediated liver injury in mice.
Inducible nitric oxide synthase (iNOS) has been shown to play an important role in the development of liver injury. iNOS deficiency protects mice from hemorrhage/resuscitation as well as from cytokine-mediated liver injury, for example, after administration of concanavalin A (con A). Here we investigated the in vivo effects of tumor necrosis factor (TNF)-alpha and/or interferon (IFN)-gamma, two mediators of con A-induced liver injury, the TNF receptor (TNFR) usage leading to iNOS expression, and its connection with nuclear factor kappaB (NF-kappaB) activation. In conclusion, iNOS expression in vivo is dependent on both TNF-alpha and IFN-gamma. Although con A-induced liver injury depends on both TNFR1 and TNFR2, TNF-dependent iNOS expression is mediated exclusively by TNFR1 and requires NF-kappaB activation. Topics: Animals; Antibodies; Antigens, CD; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Expression Regulation, Enzymologic; Interferon-gamma; Liver Diseases; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Receptors, Tumor Necrosis Factor, Type II; Signal Transduction; Tumor Necrosis Factor-alpha | 2002 |
Antithrombin III prevents concanavalin A-induced liver injury through inhibition of macrophage inflammatory protein-2 release and production of prostacyclin in mice.
Recently, we have reported that macrophage inflammatory protein-2 (MIP-2) plays a pivotal role in concanavalin A (Con A)-induced liver injury. In this study, we investigated the effect of antithrombin III (AT-III) on liver damage, and production of MIP-2 and prostacyclin in this model.. Liver injury was induced by intravenous injection of Con A (15 mg/kg) and AT-III was administered (50, 250 and 500 units/kg, iv) 30 mm before Con A injection. Plasma levels of alanine aminotransferase (ALT), MIP-2 and 6-keto-prostaglandin F1alpha (6k-PG-F1alpha), stable metabolite of prostaglandin I(2) (prostacyclin), were determined.. The elevated plasma ALT levels 8, 16, 24 h after Con A injection were inhibited by AT-III pretreatment. The elevated plasma MIP-2 levels were significantly inhibited by AT-III pretreatment compared with vehicle treatment. The inhibitory effect of AT-III on plasma ALT and MIP-2 in Con A-induced liver injury was attenuated by indomethacin (5 mg/kg, ip). Plasma concentration of 6k-PG-F1alpha at 2 h after AT-III injection was significantly elevated compared with baseline and vehicle pretreatment.. These findings suggest that AT-III prevents Con A-induced liver injury through an inhibition of MIP-2 release and a production of prostacyclin. Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antineoplastic Agents; Antithrombin III; Chemical and Drug Induced Liver Injury; Chemokine CXCL2; Chemokines; Concanavalin A; Cytokines; Epoprostenol; Female; Indomethacin; Liver Diseases; Mice; Mice, Inbred BALB C; Monokines; Neutrophils; Recombinant Proteins; Serine Proteinase Inhibitors; Specific Pathogen-Free Organisms; Tumor Necrosis Factor-alpha | 2002 |
Protective effects of cyclosporine A on T-cell dependent ConA-induced liver injury in Kunming mice.
Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclosporine; Disease Models, Animal; Immunosuppressive Agents; Liver; Liver Diseases; Male; Mice; Mice, Inbred Strains; T-Lymphocytes; Tumor Necrosis Factor-alpha | 2001 |
Studies on the influence of a Se-restricted diet on the effects of long-term increased copper intake in guinea pigs.
Guinea pigs were exposed to Se-restriction/deficiency in combination with drinking water containing 200 or 300 mg Cu/l for 6-30 weeks. Under the influence of Se-restriction/deficiency Cu excretion by bile was diminished, the Cu content of the kidneys was increased and disturbances of liver function were seen in animals exposed for prolonged periods. Some parameters of the immune system, such as the phagocytic activity of peritoneal macrophages, mitogenicity of spleen lymphocytes and the amount of lymphatic spleen tissue were also adversely affected. These effects correlated in part with the liver damage and the copper content of the kidneys. Conclusion are drawn with respect to the Idiopathic Copper Toxicosis/Indian Childhood Cirrhosis. Topics: Animals; Bile; Chemical and Drug Induced Liver Injury; Concanavalin A; Copper; Diet; Drinking; Guinea Pigs; Kidney; Lipopolysaccharides; Liver; Liver Diseases; Lymphocyte Activation; Lymphocytes; Macrophages, Peritoneal; Phagocytosis; Selenium; Spleen | 2000 |
Importance of Kupffer cells for T-cell-dependent liver injury in mice.
T cells seem to be responsible for liver damage in any type of acute hepatitis. Nevertheless, the importance of Kupffer cells (KCs) for T-cell-dependent liver failure is unclear. Here we focus on the role of KCs and tumor necrosis factor (TNF) production after T cell stimulation in mice. T-cell- and TNF-dependent liver injury were induced either by Pseudomonas exotoxin A (PEA), by concanavalin A (Con A), or by the combination of subtoxic doses of PEA and the superantigen Staphylococcus enterotoxin B (SEB). KCs were depleted by clodronate liposomes. Although livers of PEA-treated mice contained foci of confluent necrosis and numerous apoptotic cells, hardly any apoptotic cells were observed in the livers of Con A-treated mice. Instead, large bridging necroses were visible. Elimination of KCs protected mice from PEA-, Con A-, or PEA/SEB-induced liver injury. In the absence of KCs, liver damage was restricted to a few small necrotic areas. KCs were the main source of TNF. Hepatic TNF mRNA and protein production were strongly attenuated because of KC-depletion whereas plasma TNF levels were unaltered. Our results suggest that KCs play an important role in T cell activation-induced liver injury by contributing TNF. Plasma TNF levels are poor diagnostic markers for the severity of TNF-dependent liver inflammation. Topics: ADP Ribose Transferases; Animals; Antigens, Bacterial; Bacterial Toxins; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Combinations; Enterotoxins; Exotoxins; Kupffer Cells; Liver; Liver Diseases; Male; Mice; Mice, Inbred BALB C; Necrosis; Pseudomonas aeruginosa Exotoxin A; T-Lymphocytes; Tumor Necrosis Factor-alpha; Virulence Factors | 2000 |
Involvement of intrasinusoidal hemostasis in the development of concanavalin A-induced hepatic injury in mice.
Concanavalin A (Con A) stimulation induces T-cell activation-associated hepatic injury. This study is designed to show the involvement of microcirculatory disturbance in the pathogenesis. Con A administration led to prominent intrasinusoidal hemostasis, which consisted of erythrocyte agglutination, lymphocyte/neutrophil sticking to endothelial cells, and platelet aggregation and degranulation, resulting in a marked decrease in the intrahepatic blood flow and elevation of portal perfusion pressure. After hemostasis, confluent hepatic necrosis occurred within the congested area of liver parenchyma. Reduction in the extent of hemostasis by the treatment with heparin (thrombin inhibitor) or cyproheptadine (serotonin inhibitor) decreased hepatic injury. Pretreatment with either anti-tumor necrosis factor alfa (TNF-alpha) or anti-interferon gamma (IFN-gamma) monoclonal antibody (MAb) moderately decreased hemostasis and hepatic injury, whereas combined use of two MAbs almost perfectly protected mice from these disorders. Complete obliteration of hemostasis and hepatic injury was also accomplished by the pretreatment with FK506 which suppressed TNF-alpha and IFN-gamma production. Intrasinusoidal accumulation of leukocytes and platelets was, however, not blocked by FK506, indicating that Con A activities other than the stimulation of cytokine production are responsible for this event. The administration of anti-CD3 MAb, a T-cell stimulant without agglutination activities, which elevated plasma cytokine levels in a comparable degree without inducing prominent leukocyte infiltration, did not induce hepatic congestion and injury. These findings indicate that the agglutination activities of Con A and T-cell activation mediated TNF-alpha/IFN-gamma production are both required for the induction of intrasinusoidal hemostasis, which is indispensable for the development of hepatic injury. Topics: Animals; Antibodies, Monoclonal; CD3 Complex; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyproheptadine; Cytokines; Female; Hemostasis; Heparin; Interferon-gamma; Liver Diseases; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Electron; Tacrolimus; Time Factors; Tumor Necrosis Factor-alpha | 1998 |
Adult Schistosoma mansoni worms positively modulate soluble egg antigen-induced inflammatory hepatic granuloma formation in vivo. Stereological analysis and immunophenotyping of extracellular matrix proteins, adhesion molecules, and chemokines.
Synchronized liver granulomas were induced by injecting Sepharose beads to which SEA soluble egg antigen (SEA) or the concanavalin A binding fraction of SEA had been coupled into a mesenteric vein in naive, single-sex (35 days) and bisexually (28 days) Schistosoma mansoni-infected and Plasmodium berghei-immunized mice. Stereological analysis revealed that peak granuloma formation was already reached 8 days after injection in single-sex infected mice compared with 16 days in naive animals. No difference in granuloma formation between naive and P. berghei-immunized animals and between unisexually and bisexually S. mansoni-infected mice was observed. This suggests that the positive immunomodulatory effect on the granulomogenesis is worm specific and not likely to be due to arousal of the immune system by unrelated factors, nor is it influenced by the gender or degree of maturation of female worms. At all stages in time, the concanavalin A binding-fraction-induced granulomas reached only 65 to 70% of the volume of SEA-induced granulomas. Immunophenotyping of extracellular matrix proteins around deposited heads revealed that fibronectin was the dominant extracellular matrix protein and that also type I and IV collagen and laminin were deposited. Temporal analysis of the expression of the adhesion molecules ICAM-1, LFA-1, VLA-4, and VLA-6 was performed. Morphological evidence is presented for the role of adhesion molecules in the initiation and maintenance of hepatic granuloma formation. The chemokine monocyte chemoattractant protein-1 was expressed in the granuloma and in hepatic artery branches. From these data, it is concluded that adult S. mansoni worms positively modulate schistosomal hepatic granuloma formation in vivo. Adhesion molecules and chemokines play important roles in schistosomal granuloma formation. Topics: Animals; Antigens, Helminth; Collagen; Concanavalin A; Cricetinae; Disorders of Sex Development; Egg Proteins; Fibronectins; Granuloma; Immunohistochemistry; Integrin alpha4beta1; Integrin alpha6beta1; Integrins; Intercellular Adhesion Molecule-1; Laminin; Liver Diseases; Lymphocyte Function-Associated Antigen-1; Male; Mice; Mice, Inbred Strains; Plasmodium berghei; Protozoan Proteins; Receptors, Lymphocyte Homing; Schistosomiasis mansoni; Sex Factors; Spleen | 1997 |
Concanavalin A induces perforin-mediated but not Fas-mediated hepatic injury.
Concanavalin A (Con A) induces T-cell-mediated hepatic injury in vivo, although Con A-stimulated lymphocytes are not cytotoxic to normal hepatocytes in vitro. This contradiction makes the mechanism of Con A-induced hepatitis elusive. In this study, we demonstrate that Con A but not tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), or actinomycin D (ActD) induced the susceptibility of hepatocytes to activated autologous lymphocyte cytotoxicity. Con A sensitized hepatocytes within 30 minutes after the stimulation in a dose-dependent fashion. The cytotoxicity was dose-dependently inhibited by either a Con A ligand, alpha-methyl mannoside, or a perforin inhibitor, concanamycin A (CMA), but not by anti-Fas ligand antiserum. In addition, Con A-treated hepatocytes were not sensitive to autologous activated lymphocytes from a perforin-deficient mouse, while hepatocytes from lpr mice were sensitized by Con A. In fact, Con A did not induce liver injury in perforin-deficient mice within the concentration employed in this study. Therefore, we conclude that the cytotoxicity was mediated through perforin/granzymes but not through the Fas/Fas ligand pathway. The cytotoxicity was inhibited by anti-intercellular adhesion molecule-1 (ICAM-1)/LFA-1 antibodies, but not by anti-VCAM-1/VLA-4 antibodies, both in vitro and in vivo. The cytotoxicity appears to be caused by CD8+ T cells; however, the cytokines from activated CD4+ T cells play a critical role in the pathogenesis of the hepatitis in vivo, because administration of anti-IFN-gamma antibodies inhibited the occurrence of the hepatitis. In conclusion, Con A-induced hepatitis is thought to be dominantly mediated by a perforin-dependent pathway through ICAM-1/LFA-1 interaction. Topics: Animals; CD4-Positive T-Lymphocytes; Cell Adhesion Molecules; Chemical and Drug Induced Liver Injury; Concanavalin A; fas Receptor; Liver; Liver Diseases; Lymphocyte Activation; Lymphocytes; Membrane Glycoproteins; Mice; Perforin; Pore Forming Cytotoxic Proteins; T-Lymphocytes, Cytotoxic | 1996 |
Alpha-fetoprotein-concanavalin A binding as a marker to discriminate between germ cell tumours and liver diseases.
In order to differentiate whether slight alpha-fetoprotein (AFP) increases observed in any patient are due to germ cell tumours (GCT) or to liver diseases (including hepatotoxicity of chemotherapy), we measured the binding ratio of the AFP to concanavalin A (ConA). A total of 218 serum samples were studied: 102 samples from 72 GCT patients and 116 from patients with liver diseases. Considering a cut-off value to be a ConA binding ratio of 15%, we distinguished AFP produced by GCT (> 15%) from AFP produced by tumoral and non-tumoral liver diseases (< or = 15%) with a sensitivity of 98% and specificity of 100%. The difference between mean ConA binding ratios was statistically significant (P < 0.0001). We did not distinguish AFP produced by tumoral and non-tumoral liver diseases. ConA binding ratio may be a sensitive index to distinguish whether an increase of AFP concentration as low as 15 U/ml in a GCT patient during the follow-up is produced by the tumour or by liver dysfunction (including hepatotoxicity of chemotherapy). Topics: alpha-Fetoproteins; Biomarkers, Tumor; Concanavalin A; Diagnosis, Differential; Germinoma; Humans; Liver Diseases; Sensitivity and Specificity | 1995 |
Variations in the glycoforms of serum alpha 1-antichymotrypsin in liver diseases and after liver transplantation.
1. Using crossed immunoaffinity electrophoresis with free concanavalin A in the first dimension, we studied the microheterogeneity of alpha 1-antichymotrypsin due to various glycoforms in sera from patients with various liver diseases and after liver transplantation. 2. Studies by isoelectric focusing and immunoblotting and by crossed immunoelectrophoresis without concanavalin A in the first dimension allowed us to show that there is no dramatic variation in electrophoretic heterogeneity of alpha 1-antichymotrypsin in the serum of patients with liver diseases or after liver transplantation when compared with that of normal subjects. Therefore the heterogeneity observed in crossed immunoaffinity electrophoresis is due to various interactions with concanavalin A. 3. The results were expressed as the ratio of concanavalin A non-reactive glycoforms plus concanavalin A weakly reactive glycoforms to concanavalin A reactive glycoforms, called R alpha 1-ACT. R alpha 1-ACT was significantly higher in patients with cirrhosis (n = 53) when compared with normal subjects (n = 30). The median R alpha 1-ACT was 1 (range 0.72-1.25) in normal subjects. It was 1.6 (range 1.18-3.02), 1.45 (range 0.65-4.12) and 2.24 (range 1.03-19) in cirrhosis of Child's grade A, B and C, respectively. There was a dramatic decrease in glycoforms with mostly biantennary glycans in some patients with Child's grade C cirrhosis. Serum levels of alpha 1-antichymotrypsin were lower than normal only in some patients with Child's grade C cirrhosis. 4. Among the patients with acute viral hepatitis studied (n = 17), five were studied longitudinally.(ABSTRACT TRUNCATED AT 250 WORDS) Topics: Adult; Aged; Aged, 80 and over; alpha 1-Antichymotrypsin; Concanavalin A; Female; Glycosylation; Hepatitis, Viral, Human; Humans; Immunoelectrophoresis, Two-Dimensional; Isoelectric Focusing; Liver Cirrhosis; Liver Diseases; Liver Transplantation; Male; Middle Aged | 1992 |
Differential binding of serum glycoproteins to lectins during hepatic regeneration in hepatocellular carcinoma and fulminant hepatic failure.
1. The concentrations of four serum glycoproteins, thyroxine-binding globulin, alpha 2-macroglobulin, alpha 1-antitrypsin and transferrin, as well as their reactivities with concanavalin A and lentil-lectin, were measured in patients with hepatocellular carcinoma or fulminant hepatic failure and in normal subjects. 2. Serum concentrations of thyroxine-binding globulin and alpha 1-antitrypsin were significantly greater in patients with hepatocellular carcinoma than in normal subjects, and the percentage lentil-lectin reactivity of these two proteins was markedly increased. 3. With the exception of transferrin, which did not bind to lentil-lectin, an enhancement of lentil-lectin reactivity was observed for the glycoproteins in serum from patients with fulminant hepatic failure. No difference in concanavalin A binding was found between the groups for any of the glycoproteins. 4. Altered fucosylation, as indicated by increased lentil-lectin binding, occurs in several glycoproteins arising in malignant and non-malignant conditions associated with abnormal hepatic regeneration. Topics: Adult; Aged; alpha 1-Antitrypsin; alpha-Macroglobulins; Carcinoma, Hepatocellular; Chromatography, Affinity; Concanavalin A; Glycoproteins; Humans; Lectins; Liver Diseases; Liver Neoplasms; Liver Regeneration; Middle Aged; Plant Lectins; Thyroxine-Binding Proteins; Transferrin | 1990 |
Serum alpha-fetoprotein levels and microheterogeneity in patients with different liver diseases.
Serum alpha-fetoprotein levels were determined in patients (268) with liver disease. Markedly elevated concentrations (greater than 100 micrograms/l) were found in twelve patients with malignant tumours and two with cirrhosis. Molecular variants of alpha-fetoprotein were distinguished by lectin affinity chromatography of these sera. Reversible binding to concanavalin A (86 +/- 5%) and to lentil agglutinin (61 +/- 19%) conformed to expected values for primary hepatocellular carcinoma except in one patient with a metastatic carcinoma whose alpha-fetoprotein binding to concanavalin A was similar to non-liver alpha-fetoprotein (44 +/- 13%), and the two patients with cirrhosis in whom binding to lentil agglutinin was typical for benign liver disorders (less than 20%). Since low levels of serum alpha-fetoprotein and non-characteristic alpha-fetoprotein binding patterns assisted in the regrouping of eleven out of 24 patients initially thought to have primary hepatocellular carcinoma, it was concluded that alpha-fetoprotein determination and lectin affinity chromatography are helpful in distinguishing primary hepatocellular carcinoma from metastatic and benign liver diseases. Slight increases in the alpha-fetoprotein level in the presence of serum hepatitis B surface antigen indicated seven patients at risk for primary hepatocellular carcinoma who should be monitored frequently. Topics: alpha-Fetoproteins; Carcinoma, Hepatocellular; Chromatography, Affinity; Concanavalin A; Female; Genetic Variation; Humans; Lectins; Liver Diseases; Liver Neoplasms; Male; Middle Aged | 1990 |
Interactions between adherent mononuclear cells and lymphocytes from granulomas of mice with schistosomiasis mansoni.
T-lymphocyte-adherent mononuclear cell interaction was analyzed in the vigorous and immunomodulated liver granulomas of Schistosoma mansoni-infected mice. Collagenase-dispersed granulomas contained 15% lymphocytes, 30% macrophages, 50% eosinophilis, and some neutrophils. Dispersed granuloma cells stimulated with concanavalin A or soluble worm egg antigens (SEA) did not proliferate unless plate-adherent, esterase-positive mononuclear cells were removed before culture. To analyze the granuloma adherent cell-mediated suppression, vigorous granuloma cell cultures partially depleted of adherent mononuclear cells were supplemented with indomethacin, catalase, superoxide dismutase, levamisole, and anti-murine alpha/beta interferon antiserum. In concanavalin A and SEA-stimulated cultures, only the addition of indomethacin or anti-alpha/beta interferon antiserum alleviated the adherent cell-mediated suppression of vigorous granuloma lymphocyte response. In contrast, these agents only minimally alleviated the suppressed response of SEA-stimulated, immunomodulated granuloma lymphocytes. Moreover, coculture of equal numbers of vigorous and immunomodulated granuloma cells partially depleted of adherent suppressor cells abrogated the alleviated response of vigorous granuloma lymphocytes. These findings indicate that, within the schistosome egg-induced vigorous granulomas, the adherent mononuclear cells exert regulation over lymphocyte responsiveness by alpha/beta-interferon and an indomethacin-sensitive, probably prostaglandin-mediated pathway. Within the immunomodulated granulomas, the adherent suppressor cell-mediated regulation of lymphocyte proliferation appears to play a lesser role. Topics: Animals; Antigens, Helminth; Concanavalin A; Granuloma; Immune Tolerance; Indomethacin; Interferon Type I; Leukocytes, Mononuclear; Liver Diseases; Lymphocyte Activation; Lymphocytes; Mice; Mice, Inbred CBA; Schistosomiasis mansoni | 1990 |
Detection of antibodies against Opisthorchis viverrini in patients before and after treatment with praziquantel.
Levels of antibody in sera of 78 patients with opisthorchiasis, 30 patients with other liver diseases, 10 patients with schistosomiasis and 30 healthy individuals were compared using three serodiagnostic tests, namely indirect haemagglutination (IHA), enzyme-linked immunosorbent assay (ELISA) and lectin immuno test (LIT). The geometric mean reciprocal titer in sera of opisthorchiasis patients was significantly higher than patients with other diseases, patients with schistosomiasis and healthy individuals (p less than 0.00001). After treatment with praziquantel, the antibody titers were decreased and became lowest 120 days after treatment. A statistically significant decrease from the pre-treatment sample was observed only at 120 days after infection and not earlier and only with ELISA (p = 0.03) and not with IHA and LIT (p greater than 0.05). Even with ELISA, significant decrease in antibody titer was apparent only when the pre-treatment sera had high enough antibody titer. ELISA was therefore better than the other two tests for the assessment of cure provided that the titer of pre-treatment sera was high. Topics: Animals; Antibodies, Helminth; Concanavalin A; Enzyme-Linked Immunosorbent Assay; Hemagglutination Tests; Humans; Liver Diseases; Opisthorchiasis; Opisthorchis; Praziquantel; Schistosomiasis japonica; Sensitivity and Specificity; Serologic Tests; Thailand | 1988 |
Differential reactivity of alpha-fetoprotein with lectins and its usefulness in the diagnosis of various liver diseases.
Serum from 38 patients with liver disease and elevated serum AFP concentration was subjected to affinity chromatography on concanavalin A (Con A) and lentil lectin. More than 70% of the serum AFP of the 18 patients with primary liver cancer (PLC) or the 12 patients with cirrhosis or chronic active hepatitis (BLD) bound to Con A, less than 70% of the serum AFP of 8 patients with metastatic liver disease (MLD) bound to Con A. On the other hand less than 20% of the serum AFP of the BLD patients but more than 20% of the serum AFP of the PLC or MLD patients bound to lentil lectin. Thus reactivity of serum AFP towards Con A and lentil lectin provides a simple test that can be used in the differential diagnosis of BLD, PLC and MLD. Topics: Adult; Aged; Aged, 80 and over; alpha-Fetoproteins; Chromatography, Affinity; Concanavalin A; Female; Humans; Lectins; Liver Diseases; Male; Middle Aged; Plant Lectins | 1987 |
Lectin-affinity chromatography of serum gamma-glutamyltransferase in liver disease.
The variation of the carbohydrate chain of gamma-glutamyltransferase was studied in 45 liver patients by means of lectin affinity chromatography. Five lectins were used: concanavalin A, Ricinus communis I and II, Maclura pomifera and Ulex europaeus agglutinin. The binding towards Con A was shown to be independent from the binding towards the other lectins. Parallel variations of binding results against the galactose- and fucose-recognizing lectins were obtained. In liver steatosis, the binding results were comparable to those obtained in normal patients. Cirrhosis and metastasis patients showed a decreased binding towards Con A, while the binding against the various galactose- and fucose-recognizing lectins was increased. After neuraminidase treatment, an increased affinity towards all lectins was observed. However, differences in RCA I and RCA II binding between patients and controls still persisted. Besides sialic acid, also galactose and fucose residues contribute to serum gamma-glutamyltransferase heterogeneity. Topics: Adult; Aged; Aged, 80 and over; Chromatography, Affinity; Concanavalin A; gamma-Glutamyltransferase; Humans; Lectins; Liver Diseases; Middle Aged; Neuraminidase; Regression Analysis | 1987 |
[The early detection of hepatocellular cancer by using alpha-feto-protein microheterogeneity].
Topics: Adult; alpha-Fetoproteins; Carcinoma, Hepatocellular; Concanavalin A; Diagnosis, Differential; Female; Humans; Immunoelectrophoresis, Two-Dimensional; Lectins; Liver Diseases; Liver Neoplasms; Male; Middle Aged; Plant Lectins | 1986 |
Alterations in relative proportions of microheterogenous forms of human alpha 1-acid glycoprotein in liver disease.
To determine whether liver damage correlates with typical changes in alpha 1-acid glycoprotein (alpha 1-AGP) carbohydrate branching, we selected patients with liver disease determined by histological liver findings. The severity of their illness was assessed by a clinical classification depending on the presence singly or together of four clinical complications (jaundice, ascites, hepatic encephalopathy and weight loss). An alpha 1-AGP crossed immunoelectrophoresis with Concanavalin A, an easy-to-perform method, revealed 3 or 4 subpopulations, the areas of which were calculated. A ratio R was determined as the most anodic peak area relative to the other ones. In our experimental conditions a ratio R value exceeding 1 correlated with the presence of one or more clinical complications. These results, evidencing fluctuations in the proportion of the carbohydrate variants of alpha 1-AGP, lead us to propose such a ratio as an index for grading liver damage. The sensitivity of this test was 86% and its specificity was 83%. Topics: Clinical Laboratory Techniques; Concanavalin A; Humans; Immunoelectrophoresis, Two-Dimensional; Liver Diseases; Liver Function Tests; Orosomucoid; Reference Values | 1986 |
T suppressor cell function and number in children with liver disease.
Con A stimulated suppressor cell function and the proportion of suppressor T cells were reduced in children with untreated chronic active hepatitis (CAH) but were normal in corticosteroid treated CAH patients, patients with severe acute hepatitis and inactive chronic liver disease. Adults with CAH also have defective suppressor function but a normal proportion of T suppressor cells. This difference may account for the observation that relapse after treatment withdrawal is less frequent in children than in adults. Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Female; Hemolytic Plaque Technique; Hepatitis; Hepatitis, Chronic; Humans; Immunoglobulin G; Immunoglobulin M; Leukocyte Count; Liver Diseases; Male; Pokeweed Mitogens; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory | 1985 |
Concanavalin A induced suppression of lymphocyte proliferation in chronic liver disease. A study of suppressor and responder populations in autologous and allogeneic systems.
Abnormal T-cell regulation of lymphocyte proliferation may contribute towards tissue damaging mechanisms in chronic liver disease. We therefore studied Concanavalin A induced suppressor cell activity in T-T interaction in 47 patients with chronic liver disease, using both an autologous and an allogeneic system. In the autologous system, no differences were found between those with auto-immune chronic active hepatitis, HBsAg positive chronic active hepatitis, primary biliary cirrhosis, alcoholic liver disease and normal controls. However, several abnormalities were identified in allogeneic cultures with normal lymphocytes which allowed separate analysis of the influence of suppressor and responder cells from patients with chronic liver disease. An abnormality of the suppressor population was found in those with autoimmune chronic active hepatitis, primary biliary cirrhosis and alcoholic liver disease, while the responder population was abnormal in those with autoimmune or HBsAg positive CAH. Failure to demonstrate an abnormality in an autologous system may reflect a combined defect of suppressor and responder populations, and in this study the allogeneic system was a more sensitive index of abnormal cellular T-T interaction. Topics: Autoimmune Diseases; Chronic Disease; Concanavalin A; Hepatitis B Surface Antigens; Humans; Liver Diseases; Lymphocyte Activation; T-Lymphocytes, Regulatory | 1985 |
Alpha-fetoprotein variants and their clinical significance.
Topics: alpha-Fetoproteins; Carcinoma, Hepatocellular; Concanavalin A; Humans; Immunoelectrophoresis; Liver Diseases; Liver Neoplasms | 1984 |
[Analysis of lectin-affinity of alpha fetoprotein-diagnostic approach].
Lectin affinities of AFP were analyzed using Con A sepharose chromatography and crossed immuno-affino-electrophoresis. With Con A, AFP was divided into three subfractions, nonbound, loosely-bound and tightly-bound by chromatography, or two subfractions, nonbound and bound by electrophoresis. Con A nonbound subfraction was small in percentage in hepatocellular carcinoma (HCC), neonatal hepatitis, congenital biliary atresia (CBA), liver cirrhosis (LC) and cord sera. In contrast with these, the increase of Con A non-bound AFP was observed in yolk sac tumor (YST) and metastatic liver cancer (Meta). With LCA, AFP was divided into three subfractions: nonbound, loosely bound and tightly bound. Loosely bound fraction was very small in every specimen. AFPs from cord sera and LC showed uniform LCA affinity pattern, but AFPs from HCC were not uniform. Our data suggest that the analyses of lectin affinity of AFP serve as a diagnostic tool in differentiating (1) HCC from YST, (2) HCC from Meta, (3) CBA or neonatal hepatitis from YST and (4) LC from some cases of HCC. Topics: alpha-Fetoproteins; Child; Child, Preschool; Chromatography; Concanavalin A; Diagnosis, Differential; Electrophoresis; Female; Humans; Infant; Infant, Newborn; Lectins; Liver Diseases; Male; Mesonephroma; Plant Lectins; Protein Binding | 1983 |
Activation of suppressor function of human peripheral blood T cells by (+)cyanidanol-3: its application to chronic active liver diseases.
(+)Cyanidanol-3, a substance belonging to the flavonoids group, has been used in acute viral hepatitis (AVH) and chronic active liver disease (CALD). Studies were undertaken to determine if (+)cyanidanol-3 could affect a function of mitogen stimulated peripheral blood lymphocytes (PBL) in humans. First, (+)cyanidanol-3 was added directly to pokeweed mitogen (PWM) stimulated PBL or co-culture of B and T cells resulting in severe suppression of immunoglobulin (Ig) production. This suppression was mediated by radiosensitive T cells. Secondly, when normal T cells pre-incubated with 25 micrograms/ml of (+)cyanidanol-3 for 48 h were cultured with freshly prepared autologous or allogeneic normal PBL in the presence of PWM, Ig production was markedly suppressed. Similarly, there was a consistent suppression of blast transformation of concanavalin A (Con A) stimulated autologous or allogeneic responding PBL by (+)cyanidanol-3 pre-treated normal T cells. On the other hand, (+)cyanidanol-3-induced suppressor cell activity of T cells from patients with CALD was significantly decreased (P less than 0.001) when compared with that of normal individuals. These studies may explain the therapeutic effect of (+)cyanidanol-3 on certain types of liver disease. Topics: Benzopyrans; Catechin; Cells, Cultured; Concanavalin A; Dose-Response Relationship, Drug; Humans; Immunoglobulin M; Immunoglobulins; Liver Diseases; Lymphocyte Activation; Pokeweed Mitogens; T-Lymphocytes; T-Lymphocytes, Regulatory | 1983 |
[Clinical significance of serum gamma-GTP isoenzymes].
Topics: Biliary Tract Diseases; Concanavalin A; Electrophoresis; gamma-Glutamyltransferase; Humans; Isoenzymes; Liver Diseases | 1982 |
Serum ferritin and binding of serum ferritin to concanavalin A as a tumor marker in patients with primary liver cell cancer and chronic liver disease.
Topics: Adult; Aged; alpha-Fetoproteins; Chronic Disease; Concanavalin A; Female; Ferritins; Hepatitis B; Humans; Liver Cirrhosis; Liver Cirrhosis, Alcoholic; Liver Diseases; Liver Neoplasms; Male; Middle Aged | 1982 |
Binding of serum ferritin to concanavalin A in patients with iron overload and with chronic liver disease.
Total serum ferritin and the proportion of serum ferritin binding to concanavalin A (glycosylated ferritin) was measured in 18 healthy volunteers and in 84 patients, eight with primary haemochromatosis, 43 with beta-thalassaemia major and secondary iron overload and 33 with chronic liver diseases without iron overload. The total serum ferritin was either equally or even more closely related than either the non-binding or the concanavalin A binding ferritin, to the liver iron concentration in all patients with iron overload, and with the units of blood transfused in non-chelated thalassaemic patients. The total serum ferritin showed a significant correlation with serum aminotransferase for the group of 84 patients. In the thalassaemic patients the ferritin binding to concanavalin A also correlated with aminotransferase. However, in the other groups it was the ferritin not binding to concanavalin A which showed a significant correlation with aminotransferase activity. These results suggest that measuring the fraction of serum ferritin which binds to concanavalin A does not offer any advantage over estimation of the total serum ferritin concentration in the assessment of iron stores in patients wit iron overload and liver damage. Topics: Binding Sites; Chronic Disease; Concanavalin A; Ferritins; Hemochromatosis; Humans; Iron; Liver; Liver Diseases; Thalassemia; Transaminases | 1982 |
Lymphocyte suppressor cell activity in acute and chronic liver disease.
We investigated lymphocyte suppressor cell activity in 53 patients with acute and chronic liver diseases. Suppressor cells were generated by preincubation of peripheral blood mononuclear cells (PBM) with concanavalin A (Con A) for 48 hr. Suppressor cell activity was evaluated by inhibition of Con A-stimulated blast transformation and by inhibition of pokeweed mitogen-induced immunoglobulin (Ig) synthesis of fresh allogeneic normal PBM in the second-set cultures. Of 29 patients with chronic active liver diseases (CALD), defective suppressor cell activities were observed in eight cases (28%) for Ig synthesis and 16 cases (55%) for blast transformation study. The suppressor cell activities were decreased in two (22%) of nine cases with chronic persistent hepatitis and one (17%) of six cases with inactive cirrhosis for both Ig synthesis and blast transformation. In contrast, suppressor activities were inducible in all nine patients with acute viral hepatitis. The histocompatibility antigen DR4 was significantly increased in CALD patients, but there was no correlation between this antigen and suppressor cell activity. These findings suggest that altered lymphocyte suppressor cells in patients with CALD may contribute to the continuing liver cell injury in this disease. Topics: Acute Disease; Adult; Chronic Disease; Concanavalin A; Hepatitis, Viral, Human; HLA Antigens; Humans; Immunoglobulins; Liver Diseases; Lymphocyte Activation; Middle Aged; Pokeweed Mitogens; T-Lymphocytes, Regulatory | 1981 |
Loss of suppressor T cell function and circulating immune complexes in chronic active liver diseases.
Suppressor T cell function is decreased in patients with chronic active liver diseases (CALD). To account for the alterations, we examined the effect of sera of patients with various liver diseases on concanavalin A (Con A) induced suppressor T cell activity of normal individuals. The suppressor T cell activity was inhibited by heat-inactivated serum pretreatment in 13 of 27 cases of patients with CALD and in five of 11 cases of patients with acute viral hepatitis, whereas only two sera of 18 patients with other liver diseases affected suppressor cell activity. Using a 125I-C1q-binding test, a significant correlation (P less than 0.01) was detected between the degree of inhibition in the development of suppressor T cells and the level of circulating immune complexes in the sera of CALD patients. The blocking effect of patients' sera disappeared when the immune complexes were removed with polyethylene glycol. These data suggest that circulating immune complexes modulate cellular immunity in patients with CALD by influencing the suppressor T cell function. Topics: Adult; Antigen-Antibody Complex; Chronic Disease; Complement Activating Enzymes; Complement C1q; Concanavalin A; Humans; Immunoglobulin G; Liver Diseases; Lymphocyte Activation; Middle Aged; Prednisone; T-Lymphocytes, Regulatory | 1981 |
[Gamma glutamyltransferase. Pathobiology and differential diagnostic value].
Topics: Breast Neoplasms; Cholestasis; Concanavalin A; Diagnosis, Differential; Digestive System Neoplasms; Female; Fetus; gamma-Glutamyltransferase; Humans; Isoenzymes; Kidney Diseases; Liver Diseases; Pregnancy | 1980 |
[Serum factors to support lymphocyte blastogenesis in patients with liver diseases (author's transl)].
Topics: Concanavalin A; Hepatitis; Humans; Liver Cirrhosis; Liver Diseases; Lymphocyte Activation | 1980 |
[Concanavalin A- Sepharose affinity chromatography for routine microanalysis of gamma-glutamyltransferase (author's transl)].
The separation of two molecular forms of liver gamma-glutamyltransferase is achieved by Con A-Sepharose chromatography, an adult type with high affinity to Con A and a fetal type without binding capacity to this lectin. Now we present a new method using micro-columns for affinity chromatography (gel volume 2 ml). By this rapid and inexpensive procedure it is possible to study this enzyme separation for its use in the diagnosis of liver diseases. Topics: Chromatography, Affinity; Concanavalin A; gamma-Glutamyltransferase; Humans; Liver Diseases; Methods; Microchemistry | 1977 |
[Isoenzyme differentiation of gamma-glutamyltransferase by concanavalin A and Con- A-Sepharose (author's transl)].
In this investigation a new possibility of isoenzyme-differentiation of the gamma-glutamyl-transferase (GGT) (EC Nr.2.3.2.2.) was demonstrated by Concanavalin A and Con A-Sepharose. Because of the different sugar content of the glycoproteins distinction between liver- and kidney-GGT is possible. Furthermore it was possible for the first time to show a different precipitation behaviour of one glycoprotein to Concanavalin A in certain diseases. In cases of alcoholic hepatitis GGT looses its Concanavalin A-affinity because of increased neuraminic acid concentration. The possible reasons of the different behaviour to the binding affinity of Con A and Con A-Sepharose and GGT as well as additional use for enzyme-differentiation by Con A-Sepharose affinity chromatography are discussed. Topics: Azathioprine; Chemical and Drug Induced Liver Injury; Chemical Precipitation; Chromatography, Affinity; Concanavalin A; Ethanol; gamma-Glutamyltransferase; Glycoproteins; Humans; Isoenzymes; Kidney Diseases; Liver Diseases; Neuraminic Acids; Neuraminidase; Polysaccharides; Sepharose | 1976 |
Immunologic dysfunction in heroin addicts.
Topics: Adult; Antibody Formation; Concanavalin A; Deoxyuridine; False Positive Reactions; Follow-Up Studies; Heroin Dependence; Humans; Immune System Diseases; Immunity, Cellular; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Iodine Radioisotopes; Lectins; Leukocytes; Liver Diseases; Lymphocytes; Methadone; Mitogens; Skin Tests; Syphilis Serodiagnosis | 1974 |