concanavalin-a and Chemical-and-Drug-Induced-Liver-Injury

Autoimmune hepatitis (AIH) is an autoimmune disease characterized by liver parenchymal destruction and chronic fibrosis. Its exact etiology and pathogenesis are not yet fully understood.(Please connect with the following, do not leave a line) Concanavalin A (Con A)-induced mice hepatitis model is a liver injury mediated by T cell and macrophage activation, and its pathogenesis and pathological changes are similar to human AIH. The establishment of this model has greatly promoted the research progress of AIH pathogenesis. However, the exact mechanism of Con A induced liver injury in mice, and its possible defects or deficiencies, has not yet been described in a clear and detailed manner. Therefore, the model has some limitations when applied to the study of the pathogenesis and treatment mechanism of AIH. This article reveals the pathogenesis of Con A induced liver injury in mice from the aspects of immune disorder and coagulation mechanism, expounds the significance of non-coding RNA in this model, summarizes the signal transduction pathways involved in this model, and summarizes the advantages and disadvantages of the model, which provides a theoretical basis and research target for the application of Con A induced liver injury model in AIH in the future.

Topics: Animals; Blood Coagulation Disorders; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatitis, Autoimmune; Liver; Mice; RNA, Untranslated; Signal Transduction

Autoimmune hepatitis (AIH) is a severe and chronic liver disease, and its incidence has increased worldwide in recent years. Research into the pathogenesis of AIH remains limited largely owing to the lack of suitable mouse models. The concanavalin A (ConA) mouse model is a typical and well-established model used to investigate T cell-dependent liver injury. However, ConA-induced hepatitis is acute and usually disappears after 48 h; thus, it does not mimic the pathogenesis of AIH in the human body. Several studies have explored various AIH mouse models, but as yet there is no widely accepted and valid mouse model for AIH. Immunosuppression is the standard clinical therapy for AIH, but patient side effects and recurrence limit its use. Regulatory T cells (Tregs) play critical roles in the maintenance of immune homeostasis and in the prevention of autoimmune diseases, which may provide a potential therapeutic target for AIH therapy. However, the role of Tregs in AIH has not yet been clarified, partly because of difficulties in diagnosing AIH and in collecting patient samples. In this review, we discuss the studies related to Treg in various AIH mouse models and patients with AIH and provide some novel insights for this research area.

Topics: Adoptive Transfer; Ammonia-Lyases; Animals; Autoantibodies; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytochrome P-450 CYP2D6; Disease Models, Animal; Glutamate Formimidoyltransferase; Hepatitis, Autoimmune; Humans; Immunosuppressive Agents; Liver; Mice; Multifunctional Enzymes; T-Lymphocytes, Regulatory

Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposure or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure.

Topics: Acetaminophen; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Fas Ligand Protein; Galactosamine; Humans; Liver Failure, Acute

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

The liver plays an important role in immunological tolerance due to its anatomical location, as it links the gastrointestinal tract and the systemic venous circulation. Therefore, immune reactions against dietary or bacterial antigens from the gut have to be avoided. However, immune responses resulting in elimination of harmful hepatotrophic pathogens have to be induced. We investigated mechanisms of tolerance induction in response to liver inflammation in a murine model of immune-mediated liver injury.. Liver damage was induced by injection of the plant lectin concanavalin A (ConA). Cytokine levels were measured in plasma and liver tissue. The frequencies of intrahepatic and splenic cell subsets were measured by FACS analyses.. ConA hepatitis was mediated by activation of CD4+ T cells, NKT cells and Kupffer cells releasing IFN-gamma and TNF-alpha. Tolerance developed towards ConA rechallenge within 8 days, lasted for several weeks and was characterized by significantly reduced plasma transaminase activities, decreased Th1/Th17 responses and an increased IL-10 release, the latter being produced by CD4+CD25+FoxP3+ regulatory T cells and Kupffer cells. Moreover, regulatory T cells from ConA-tolerant mice displayed a higher immunosuppressive potential in vitro and in vivo compared to those from non-tolerant animals. Interestingly, ConA hepatitis was aggravated in CCR5(-/-) and CXCR3(-/-) mice.. These results suggest that ConA tolerance is mediated by induced IL10+ regulatory T cells, probably trafficking into the liver depending on the IFN-gamma-inducible chemokine receptors CCR5 and CXCR3.

Topics: Animals; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Disease Models, Animal; Hepatitis, Autoimmune; Immune Tolerance; Liver; Lymphocyte Activation; Mice; Receptors, Chemokine

In infectious diseases and during inflammation, anorexia, loss of body weight, malaise, fatigue and depression are induced. These symptoms are correctively called 'sickness behaviors', and the central actions of cytokines play a role in their induction. The loss of body weight in cancer cachexia is also a result of development of sickness behaviors. It has been reported that the administration of NSAID ibuprofen to patients with cancer cachexia improves the loss in body weight. We studied the effect of NSAID on the loss of body weight by using rodent sickness behavior models. We have reported that sickness behaviors such as anorexia, decrease in body weight, and loss of locomotor activity are induced in concanavalin A (Con A)-induced mouse hepatitis and carbon tetrachloride-induced rat hepatitis. Zaltoprofen is a non-steroidal anti-inflammatory drug (NSAID) causes potent inhibition of cyclooxygenase-2 with fewer side effects on the gastrointestinal tract. Zaltoprofen improves the loss in body weight in both Con A-treated mice and carbon tetrachloride-treated rats. These results suggest the possible application of zaltoprofen for the treatment of sickness behaviors including loss of body weight occurring in cancer cachexia.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Benzopyrans; Body Weight; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Concanavalin A; Mice; Propionates; Wasting Syndrome

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

A previous study revealed that treatment with the anticoagulant heparin attenuated concanavalin A (ConA)-induced liver injury. The administration of spermidine (SPD) increased urokinase-type plasminogen activator (uPA) levels in the serum. uPA is clinically used for the treatment of some thrombotic diseases such as cerebral infarction. Therefore, SPD may attenuate ConA-induced liver injury that is exacerbated by blood coagulation. The present study investigated the effect of SPD on liver injury in mice with autoimmune hepatopathy induced by ConA. A model of liver injury was created by intravenous injection of ConA into mice. SPD was administered in free drinking water and was biochemically and pathologically examined over time. The administration of SPD to ConA-treated mice significantly reduced liver injury. However, SPD treatment upregulated the mRNA expression of TNF-α and IFN-ϒ in the livers of ConA-treated mice. In contrast, the mRNA expression of tissue factor in the livers of SPD-treated mice was decreased after ConA injection. The frequency of lymphocytes and lymphocyte activation were not affected by SPD administration in ConA-treated mice. SPD treatment increased uPA levels in the serum and decreased the level of D-dimer in ConA-treated mice. Moreover, SPD decreased fibrin in the livers of ConA-treated mice. These results indicated that SPD treatment increased anticoagulant ability by increasing of uPA and attenuated ConA-induced liver injury.

Topics: Animals; Anticoagulants; Chemical and Drug Induced Liver Injury; Chemical and Drug Induced Liver Injury, Chronic; Concanavalin A; Liver; Mice; RNA, Messenger; Spermidine

Concanavalin A (Con A) is known to be a T-cell mitogen and has been shown to induce hepatitis in mice through the triggering of conventional T cells and NKT cells. However, it remains unknown whether Con A itself can directly induce rapid hepatocyte death in the absence of a functional immune system. Here, by using an immunodeficient mouse model, we found Con A rapidly induced liver injury in vivo despite a lack of immunocyte involvement. We further observed in vitro that hepatocytes underwent a dose-dependent but caspase-independent apoptosis in response to Con A stimulation in vitro. Moreover, transcriptome RNA-sequencing analysis revealed that apoptosis pathways were activated in both our in vivo and in vitro models. We conclude that Con A can directly induce rapid but non-classical apoptosis in hepatocytes without the participation of immunocytes. These findings provide new insights into the mechanism of Con A-induced hepatitis.

Topics: Animals; Apoptosis; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis; Hepatocytes; Liver; Mice

Twenty-one new schisanhenol derivatives were synthesized, and their hepatoprotective effects against liver injury induced by concanavalin A (Con A) were evaluated in vitro using an MTT assay. The data indicated that most derivatives exhibited equivalent or better protective activity than the positive control (dimethyl dicarboxylate biphenyl, DDB) under the same conditions. Among them, compound 1b showed the most potent hepatoprotective activity against Con A-induced immunological injury. Mechanistic studies in vitro revealed that 1b inhibited cell apoptosis and inflammatory responses caused by Con A treatment via IL-6/JAK2/STAT3 signaling pathway. Consistently, it also exhibited significant hepatoprotective activity in mice with Con A-induced immunological liver injury. These results clearly indicated that 1b might be a highly potent hepatoprotective agent targeting IL-6/STAT3 signaling pathway.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclooctanes; Dose-Response Relationship, Drug; Female; Humans; Interleukin-6; Liver; Male; Mice; Mice, Inbred C57BL; Molecular Structure; Polycyclic Compounds; Protective Agents; Signal Transduction; STAT3 Transcription Factor; Structure-Activity Relationship

Discovery of anti-inflammatory drugs that can suppress T lymphocyte activation and proliferation by inhibiting TCR/CD3 and IL-2/IL-2R signaling is still needed in clinic, though rapamycin and other related reagents have made great success. Taraxasterol (TAS) is an active ingredient of dandelion, an anti-inflammatory medicinal herb with low in vivo toxicity that has long been used in China. Yet the action mechanism of TAS on lymphocytes remains elusive. The anti-inflammatory effects of TAS were evaluated in C57BL/6 mouse primary lymphocytes stimulated with concanavalin A (Con A) in vitro and in mouse model of Con A-induced acute hepatitis in vivo. Our results showed that TAS significantly suppressed Con A-induced acute hepatitis in a mouse model, reducing the hepatic necrosis areas, the release of aminotransferases, and the production of IL-2 and other inflammatory cytokines. Supporting this, in vitro study also showed that TAS reduced the production of IL-2 and the expression of IL-2 receptor subunit α (CD25) upon the stimulation of Con A, which was likely mediated by suppressing NF-κB activation. The downstream pathways of IL-2/IL-2R signaling, including the activation of PI3K/PDK1/mTOR, STAT3 and STAT5, were also suppressed by TAS. Consistently, Con A-induced T cell proliferation was also inhibited by TAS in vitro. Our data indicate that TAS can suppress both T lymphocyte activation and cell proliferation by down-regulating IL-2 expression and its signaling pathway thereby ameliorating Con A-induced acute hepatitis, highlighting TAS as a potential drug candidate for treating inflammatory diseases including autoimmune hepatitis.

Topics: Animals; Anti-Inflammatory Agents; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Interleukin-2; Liver; Mice, Inbred C57BL; Signal Transduction; Sterols; T-Lymphocytes; Triterpenes

To elucidate the role of the functional unknown gene C6orf120 in the pathogenesis of AIH and its mechanism of action, using C6orf120 knockout rats.. An autoimmune hepatitis model was established with 35 mg/kg intravenous injection of concanavalin A (Con A) in C6orf120-knockout (C6orf120. C6orf120 knockout significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and improved the histological damage in Con A-induced autoimmune liver injury.Loss of C6orf120 function significantly increased the frequency of CD3. The protective effect of C6orf120 knockout against Con A-induced hepatitis may be due to the inhibition of NKT cell activation, restriction of cytokine and chemokine activities, inhibition of JAK-STAT and Fas/FasL signaling pathway activation, and reduction in liver inflammation and hepatocyte apoptosis.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Fas Ligand Protein; Fas-Associated Death Domain Protein; Gene Knockout Techniques; Glycoproteins; Hepatitis, Autoimmune; Janus Kinases; Liver; Lymph Nodes; Male; Mice; Natural Killer T-Cells; NK Cell Lectin-Like Receptor Subfamily K; Rats, Sprague-Dawley; Rats, Transgenic; Spleen; STAT Transcription Factors

Therapeutics that impair the innate immune responses of the liver during the inflammatory cytokine storm like that occurring in COVID-19 are greatly needed. Much interest is currently directed toward Janus kinase (JAK) inhibitors as potential candidates to mitigate this life-threatening complication. Accordingly, this study investigated the influence of the novel JAK inhibitor ruxolitinib (RXB) on concanavalin A (Con A)-induced hepatitis and systemic hyperinflammation in mice to simulate the context occurring in COVID-19 patients. Mice were orally treated with RXB (75 and 150 mg/kg) 2 h prior to the intravenous administration of Con A (20 mg/kg) for a period of 12 h. The results showed that RXB pretreatments were efficient in abrogating Con A-instigated hepatocellular injury (ALT, AST, LDH), necrosis (histopathology), apoptosis (cleaved caspase-3) and nuclear proliferation due to damage (PCNA). The protective mechanism of RXB were attributed to i) prevention of Con A-enhanced hepatic production and systemic release of the proinflammatory cytokines TNF-α, IFN-γ and IL-17A, which coincided with decreasing infiltration of immune cells (monocytes, neutrophils), ii) reducing Con A-induced hepatic overexpression of IL-1β and CD98 alongside NF-κB activation, and iii) lessening Con A-induced consumption of GSH and GSH peroxidase and generation of oxidative stress products (MDA, 4-HNE, NOx) in the liver. In summary, JAK inhibition by RXB led to eminent protection of the liver against Con A-deleterious manifestations primarily via curbing the inflammatory cytokine storm driven by TNF-α, IFN-γ and IL-17A.

Topics: Aldehydes; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokine Release Syndrome; Dose-Response Relationship, Drug; Inflammation; Liver; Male; Malondialdehyde; Mice; Mice, Inbred BALB C; Nitrates; Nitriles; Nitrites; Oxidative Stress; Peroxidase; Pyrazoles; Pyrimidines

Gastrodin, the main active ingredient of Gastrodia elata Blume, has been shown to protect against many inflammatory diseases. Our study aimed to investigate the anti-inflammatory role of gastrodin in concanavalin A (ConA)-induced acute hepatitis in mice and to explore its precise mechanism.. C57BL/6 mice were administered with gastrodin (50 or 100mg/kg) for 3 days prior to intravenous injection of ConA to induce acute autoimmune hepatitis (AIH). Serum aminotransferases levels and cytokine levels were measured. Liver tissue histology was conducted to assess the degree of liver injury. Splenocytes pretreated with gastrodin were stimulated with ConA to observe splenocyte proliferation.. Gastrodin greatly reduced the level of serum aminotransferases, inflammatory cytokine such as IL-6 and TNF-α and histopathological damage in ConA-induced hepatitis. Besides, gastrodin had an inhibitory effect on liver apoptosis, and autophagy. Furthermore, gastrodin inhibited the proliferation of splenocytes in vitro. The protein expression of p-JAK2 and p-STAT3 was markedly affected by gastrodin pretreatment.. The present study indicated that gastrodin pretreatment exerted protective effects against ConA-induced acute hepatitis, partly through the inhibition of the IL6/JAK2/STAT3 pathway. Further studies are recommended to determine the potential therapeutic role of gastrodin in acute AIH.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Glucosides; Hepatitis; Mice; Mice, Inbred C57BL

Immune cells, including neutrophils, natural killer (NK) cells, T cells, NKT cells and macrophages, participate in the progression of acute liver injury and hepatic recovery. To date, there has been no systematic study on the quantitative changes in these different immune cells from initial injury to subsequent recovery.. To investigate the infiltration changes of various immune cells in acute liver injury models over time, and to study the relationship between the changes in leukocyte cell-derived chemotaxin 2 (LECT2) and the infiltration of several immune cells.. Carbon tetrachloride- and concanavalin A-induced acute liver injury models were employed to mimic toxin-induced and autoimmune-mediated liver injury respectively. The quantitative changes in various immune cells were monitored at different time points. Serum samples were collected, and liver tissues were harvested. Ly6G, CD161, CD4, CD8 and F4/80 staining were used to indicate neutrophils, NK/NKT cells, CD4. During the injury and repair process, different types of immune cells began to increase, reached their peaks and fell into decline at different time points. Furthermore, when the serum alanine transaminase (ALT) and aspartate transaminase (AST) indices reverted to normal levels 7 d after the injury, the infiltration of immune cells still existed even 14 d after the injury, showing an obvious lag effect. We found that the expression of LECT2 was upregulated in acute liver injury mouse models, and the liver injuries of Lect2-KO mice were less severe than those of wild-type mice. Compared with wild-type mice, Lect2-KO mice had different immune cell infiltration.. The recovery time of immune cells was far behind that of serum ALT and AST during the process of liver repair. LECT2 could regulate monocyte/macrophage chemotaxis and might be used as a therapeutic target for acute liver injury.

Topics: Animals; CD8-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Autoimmune; Killer Cells, Natural; Liver; Mice; Mice, Inbred C57BL; Neutrophils

To investigate the chemical characters of water-extract of Baqi Lingmao formula (BQLM formula) and its effects on anti-liver injury in model mice and live cells.. BQLM formula was composed of ten herbal medicines. We determined the contents of alkaloids, saponins, phenolic acids and flavonoid in BQLM formula by UV spectrophotometry. The active components of alkaloids and phenolic acids in BQLM formula were identified by HPLC chromatography. The anti-hepatic injury effects of BQLM formula were investigated with concanavalin A (ConA)-induced hepatitis model of mice, human liver LO2 and HepG2.2.15 cells.. BQLM formula (2 and 10 g/kg, orally) significantly improved the damages of liver tissues and functions caused by ConA in mice, reduced the infiltration of inflammatory cells into liver and inhibited the inflammatory cytokine secretion of interferon-γ, tumor necrosis factor-α and interleukin-6. BQLM formula simultaneously decreased the levels of alanine aminotransferase and aspartate aminotransferase of liver and serum, and recovered the superoxide dismutase and catalase activities of liver to normal levels in ConA-induced hepatic-injury mice. The serum of BQLM formula group stimulated the human liver LO2 cell proliferation in vitro. Further, BQLM formula obviously promoted the proliferation of normal hepatocytes (LO2 cells) and inhibited the hepatocytes death induced by ConA. It also significantly inhibited the proliferation of HepG2.2.15 cells and decreased the secretion of HBsAg and HBeAg in vitro.. BQLM formula has anti-inflammation and anti-hepatitis virus Beffects, and is capable of improving liver injury in vivo and in vitro.

Topics: Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatocytes; Liver; Mice

Immune-mediated hepatic injury plays a key role in the initiation and pathogenesis of diverse liver diseases. However, treatment choice for immune-mediated hepatic injury remains limited. Corilagin, a natural ellagitannin extracted from various traditional Chinese medicines, has been demonstrated to exhibit multiple pharmacological activities, such as anti-inflammatory, anti-tumor, and hepatoprotective properties. The present study aimed to investigate the effects of corilagin on immune-mediated hepatic injury using a murine model of concanavalin A (Con A)-induced hepatitis, which is well-characterized to study acute immune-mediated hepatitis. Herein, mice were administered corilagin (25 mg/kg) intraperitoneally twice at 12 h intervals, and 1 h later, the mice were challenged with Con A (20 mg/kg body weight); serum and liver samples were collected after 12 h. The results showed that corilagin significantly increased the survival of mice and reduced serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels. In addition, corilagin markedly improved histopathological damage, hepatocyte apoptosis, and oxidative stress in the liver. The activation of M1 macrophages in the hepatic mononuclear cells was also significantly reduced compared with that in the control group. The expression of M1 macrophage-associated proinflammatory cytokines and genes, including interleukin (IL)-6, IL-12, and inducible nitric oxide synthase (iNOS), was also decreased after corilagin treatment. Finally, the results demonstrated that corilagin regulated macrophage polarization by modulating the mitogen-activated protein kinases (MAPK), nuclear factor (NF)-κB, and interferon regulatory factor (IRF) signaling pathways. Thus, the findings indicate that corilagin protects mice from Con A-induced immune-mediated hepatic injury by limiting M1 macrophage activation

Topics: Animals; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Disease Susceptibility; Glucosides; Hydrolyzable Tannins; Inflammation Mediators; Liver Function Tests; Macrophage Activation; Macrophages; Male; Mice; Treatment Outcome

Cohousing of sick with healthy or treated animals is based on the concept of sharing an intestinal ecosystem and coprophagy, the consumption of feces, which includes sharing of the microbiome and of active drug metabolites secreted in the feces or urine. To develop a model for short-term cohousing, enabling the study of the effect of sharing an ecosystem on inflammatory states. To determine the impact of cohousing of sick and healthy mice on the immune-mediated disorders, mice injected with concanavalin A (ConA) were cohoused with healthy or sick mice or with steroid-treated or untreated mice. To determine the effect of cohousing on acetaminophen (APAP)-induced liver damage, APAP-injected mice were cohoused with N-acetyl-cysteine (NAC)-treated or untreated mice. In the ConA-induced immune-mediated hepatitis model, cohousing of sick with healthy mice was associated with the alleviation of liver damage in sick animals. Similarly, a significant decrease in serum ALT was noted in ConA-injected mice kept in the same cage as ConA-injected mice treated with steroids. A trend for reduction in liver enzymes in APAP-injected mice was observed upon cohousing with NAC-treated animals. Cohousing of sick mice with healthy or treated mice ameliorated the immune-mediated inflammatory state induced by ConA and APAP. These models for liver damage can serve as biological systems for determining the effects of alterations in the ecosystem on the immune system.

Topics: Acetaminophen; Acetylcysteine; Alanine Transaminase; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Coprophagia; Dexamethasone; Ecosystem; Gastrointestinal Microbiome; Hepatitis, Autoimmune; Housing, Animal; Male; Mice; Mice, Inbred C57BL; Treatment Outcome

Interleukin (IL)-39 is a novel member of IL-12 family and has been reported to play a pro-inflammatory role in lupus-like mice, but its function in concanavalin A (ConA)-induced liver injury is currently unclear.. In this study, we investigated the effects of IL-39 expression in a mouse model of ConA induced-hepatitis. We first showed that delivery of plasmid DNA encoding mouse IL-39 using the hydrodynamic tail vein injection method increased IL-39 mRNA and protein levels in the liver. We then administrated mice with IL-39 plasmid before ConA injection and measured serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, inflammatory infiltration, and hepatocyte necrosis in the liver. Additionally, we further explored the potential mechanism of IL-39 in ConA-induced liver injury by measuring several inflammatory mediators.. We found that ectopic IL-39 expression promoted the ConA-induced increase in serum ALT and AST levels, inflammatory infiltration, and hepatocyte necrosis in the liver. We also observed that IL-39 plasmid administration significantly increased serum and liver interferon-γ, tumor necrosis factor-α, and IL-17A levels, but did not affect serum and liver IL-10 levels in ConA-induced hepatitis.. Our results suggest that IL-39 can exacerbate ConA-induced hepatitis and may be a therapeutic target in inflammatory liver disease.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interleukins; Liver; Male; Mice; Mice, Inbred BALB C

Liver diseases with different pathogenesis share common pathways of immune-mediated injury. Chitinase-3-like protein 1 (CHI3L1) was induced in both acute and chronic liver injuries, and recent studies reported that it possesses an immunosuppressive ability. CHI3L1 was also expressed in mesenchymal stem cells (MSCs), thus we investigates the role of CHI3L1 in MSC-based therapy for immune-mediated liver injury here. We found that CHI3L1 was highly expressed in human umbilical cord MSCs (hUC-MSCs). Downregulating CHI3L1 mitigated the ability of hUC-MSCs to inhibit T cell activation, proliferation and inflammatory cytokine secretion in vitro. Using Concanavalin A (Con A)-induced liver injury mouse model, we found that silencing CHI3L1 significantly abrogated the hUC-MSCs-mediated alleviation of liver injury, accompanying by weakened suppressive effects on infiltration and activation of hepatic T cells, and secretion of pro-inflammatory cytokines. In addition, recombinant CHI3L1 (rCHI3L1) administration inhibited the proliferation and function of activated T cells, and alleviated the Con A-induced liver injury in mice. Mechanistically, gene set enrichment analysis showed that JAK/STAT signalling pathway was one of the most significantly enriched gene pathways in T cells co-cultured with hUC-MSCs with CHI3L1 knockdown, and further study revealed that CHI3L1 secreted by hUC-MSCs inhibited the STAT1/3 signalling in T cells by upregulating peroxisome proliferator-activated receptor δ (PPARδ). Collectively, our data showed that CHI3L1 was a novel MSC-secreted immunosuppressive factor and provided new insights into therapeutic treatment of immune-mediated liver injury.

Topics: Animals; Cell Proliferation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Chitinase-3-Like Protein 1; Coculture Techniques; Concanavalin A; Cytokines; Disease Models, Animal; Female; Humans; Liver; Lymphocyte Activation; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice, Inbred C57BL; Paracrine Communication; Phosphorylation; Receptors, Cytoplasmic and Nuclear; STAT1 Transcription Factor; STAT3 Transcription Factor; T-Lymphocytes; Umbilical Cord

The wide applications of titanium dioxide nanoparticles (TNP) and ubiquitous cadmium (Cd) pollution increase the chances of their co-existence in the environment and also pose potential health risks to humans. However, toxicological understanding of effects of co-exposures of TNP and Cd to mammals is still lacking. In this study, non-lethal doses of TNP and CdCl

Topics: Acute Disease; Animals; Cadmium; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Interactions; Female; Hepatitis; Liver; Mice, Inbred BALB C; Nanoparticles; Oxidative Stress; Titanium

The current study aims to investigate the role of the key effector cytokines produced by CD4+T cells in the pathogenesis of Con A-induced liver injury in mice and testing whether etanercept can be repurposed to differentially regulate these cytokines.. Four groups of mice were used: group I: control group, group II: mice received 15 mg/kg Con A i.v, group III: mice received 15 mg/kg etanercept i.p, group IV: mice received both Con A and etanercept as described. Hepatic injury and necroinflammation were assessed. Infiltration of CD4+ T cells and neutrophils were evaluated. Hepatic levels of TNF-α, IL-4, IL-10, and MDA were assigned and expression of NF-κB as well.. A significant decrease in ALT, AST, and LDH levels occurred when etanercept was injected before Con A. Hepatic necrosis and infiltration of CD4+ T cells and neutrophils were reduced by etanercept. Levels of TNF-α, IL-4, and MDA were significantly decreased in group IV compared to group II while that of IL-10 was increased. Also, number of NF-κB positive cells was significantly low in group IV.. The study elucidates an interplay between the two effector cytokines of CD4+ T cells, TNF-α and IL-4, and their key role in Con A-induced liver injury. Additionally, our results showed that etanercept could be repurposed to differentially regulate effector cytokines produced by CD4+ T cells. Not only TNF-α, but also IL-4 signaling pathways, through which it exerts immunomodulatory, anti-inflammatory, and anti-oxidant effects leading to attenuation of Con A-induced liver injury.

Topics: Animals; Anti-Inflammatory Agents; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Etanercept; Hepatitis; Immunosuppressive Agents; Male; Mice; Mice, Inbred BALB C; Mitogens; Signal Transduction

To investigate the protective effects and underlying mechanisms of diallyl trisulfide (DATS) against acute liver injury induced by concanavalin A (Con A).. DATS (20, 40, 80 mg/kg) were gavaged to ICR mice 1 h before Con A (20 mg/kg) tail vein injection. The survival rate of mice, alterations of serum biochemical markers and liver histopathology were measured to evaluate the protective effects of DATS at 24 h after Con A exposure. The indexes of inflammation, oxidative stress and apoptosis were determined to explore the possible mechanisms.. DATS pretreatment increased survival rate of mice in a dose-dependent manner, inhibited the increase of liver-to-spleen ratio and serum liver injury markers, and attenuated liver pathological damage induced by Con A. Further study showed that DATS pretreatment inhibited the activation of Kupffer cells/macrophages, release of tumor necrosis factor-α (TNF-α) and Caspase-1-dependent inflammation induced by Con A. Moreover, DATS pretreatment alleviated the oxidative stress induced by Con A, which was evidenced by increased superoxide dismutase (SOD) and catalase (CAT) activities and decreased malondialdehyde (MDA) content in DATS and Con A co-treated mice compared with Con A alone group. Finally, DATS pretreatment reduced eosinophilic body formation, TUNEL positive staining and increased Bcl-2/Bax ratio in liver of Con A-injected mice, indicating attenuated apoptosis.. Collectively, the results suggest that DATS displays potent protective effects against Con A-induced acute liver injury in mice possibly through inhibition of inflammation, oxidative stress and apoptosis.

Topics: Allyl Compounds; Animals; Anti-Inflammatory Agents; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Inflammation; Liver; Male; Mice; Mice, Inbred ICR; Oxidative Stress; Protective Agents; Sulfides

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Humans; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Mitogens

Topics: Abietanes; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Hepatitis, Autoimmune; Humans; Mice; Mice, Inbred C57BL; Molecular Structure; Phytochemicals; Plants, Medicinal; Protective Agents; Prunella; Spleen; T-Lymphocytes

Sitagliptin is known for its anti-diabetic activity though it has other pleiotropic pharmacological actions. Its effect against concanavalin A (Con A)-induced hepatic fibrosis has not been investigated yet. Our target was to test whether sitagliptin can suppress the development of Con A-induced hepatic fibrosis and if so, what are the mechanisms involved? Con A (6 mg/kg) was injected once weekly to male Swiss albino mice for four weeks. Sitagliptin was daily administered concurrently with Con A. Results have shown the potent hepatoprotective activity of sitagliptin against Con A-induced hepatitis and fibrosis. That was evident through the amelioration of hepatotoxicity serum parameters (ALT, AST, ALP, and LDH) and the increase in the level of serum albumin in sitagliptin treated mice. Simultaneously, there was amendment of the Con A-induced hepatic lesions and repression of fibrosis in sitagliptin-treated animals. Hydroxyproline, collagen content and the immuno-expression of the fibrotic markers, TGF-β and α-SMA were depressed upon sitagliptin treatment. Sitagliptin suppressed Con A-induced oxidative stress and increased antioxidants. RT-PCR analysis showed enhancement of mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its target genes (GCLc, GCLm, NQO-1, HO-1) by sitagliptin. Furthermore, sitagliptin ameliorated the level and immuno-expression of nuclear factor kappa-B (NF-κB) alongside the immuno-expression of the inflammatory cytokine, TNF-α. Taken together, this study demonstrates the hepatoprotective activity of sitagliptin which may be in part related to enhancement of Nrf2 signaling pathway and inhibition of NF-κB which interact inflammatory response in liver. Sitagliptin might be a new candidate to suppress hepatitis-associated fibrosis.

Topics: Animals; Anti-Inflammatory Agents; Antifibrotic Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Liver; Liver Cirrhosis, Experimental; Male; Mice; NF-E2-Related Factor 2; NF-kappa B; Oxidative Stress; Signal Transduction; Sitagliptin Phosphate; Tumor Necrosis Factor-alpha

Fulminant hepatitis is a serious inflammatory condition of the liver characterized by massive necrosis of liver parenchyma following excessive immune cell infiltration into the liver, and possibly causing sudden hepatic failure and medical emergency. However, the underlying mechanisms are not fully understood. Here, we investigated the role of cyclic AMP-responsive element-binding protein, hepatocyte specific (CREBH) in concanavalin A (ConA)-driven hepatitis-evoked liver injury. C57BL/6J (WT) and Crebh knockout (KO) mice injected with ConA (7.5 or 25 mg/kg) and bone marrow (BM) chimeric mice, generated by injection of BM cells into sub-lethally irradiated recipients followed by ConA injection (22.5 or 27.5 mg/kg) 8 weeks later, were used for in vivo study. Primary mouse hepatocytes and HEK293T cells were used for a comparative in vitro study. Crebh KO mice are highly susceptible to ConA-induced liver injury and prone to death due to increased neutrophil infiltration driven by enhanced hepatic expression of neutrophil-attracting chemokines. Notably, BM chimera experiment demonstrated that Crebh-deficient hepatocytes have an enhanced ability of recruiting neutrophils to the liver, thereby promoting hepatotoxicity by ConA. Intriguingly, in vitro assays showed that p65, a subunit of NF-κB and common transcription factor for various chemokines, dependent transactivation was inhibited by CREBH. Furthermore, p65 expression was inversely correlated with CREBH level in ConA-treated mice liver and TNFα-stimulated primary mouse hepatocytes. This is the first demonstration that CREBH deficiency aggravates inflammatory liver injury following chemokine-dependent neutrophil infiltration via NF-κB p65 upregulation. CREBH is suggested to be a novel therapeutic target for treatment of fulminant hepatitis.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Cyclic AMP Response Element-Binding Protein; Cytokines; HEK293 Cells; Humans; Male; Massive Hepatic Necrosis; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Transcription Factor RelA; Up-Regulation

Serotonin is involved in the pathological processes of several liver diseases via the regulation of inflammatory response and oxidative stress. We aimed to investigate the role of serotonin in Concanavalin A- (Con A-) induced acute liver injury (ALI). ALI was induced in C57B/6 wild-type (WT) mice and tryptophan hydroxylase 1 (TPH1) knockout mice through tail vein injection of Con A (15 mg/kg body weight). Another group of TPH1 knockout ALI mice was supplied with 5-hydroxytryptophan (5-HTP) in advance to recover serotonin. The blood and liver tissues of mice were collected in all groups. Markedly increased serum levels of serotonin were identified after the injection of Con A. Increased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and stronger hepatic tissue pathology were detected, suggesting that serotonin could mediate Con A-induced liver damage. Serotonin significantly facilitated the release of serum and intrahepatic inflammatory cytokines, including interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-17A (IL-17A), interferon-gamma (IFN-

Topics: Animals; Apoptosis; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Male; Malondialdehyde; Mice; Mice, Knockout; Nitric Oxide; Peroxidase; Receptor, Serotonin, 5-HT2A; Serotonin; Signal Transduction; Tryptophan Hydroxylase

Acute liver injury (ALI) is a serious health condition associated with rising morbidity and sudden progression. This study was designed to investigate the possible hepatocurative potential of two dose levels (30 and 60 mg/kg) of Mycophenolate mofetil (MMF), an immune-suppressant agent, against Concanavalin A (Con A)-induced ALI in mice.. A single dose of Con A (20 mg/kg, IV) was used to induce ALI in mice. MMF (30 mg/kg and 60 mg/kg) was administered orally for 4 days post Con A injection.. MMF (30 mg/kg) failed to cause significant amelioration in Con A-induced ALI while MMF (60 mg/kg) significantly alleviated Con A-induced ALI. Administration of MMF (60 mg/kg) significantly decreased Con A-induced increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Additionally, MMF significantly restored the disrupted oxidant/antioxidants status induced by Con A. MMF caused marked increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels. Moreover, MMF significantly reduced Con A-induced increase in the expression of hepatic toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ) and interleukin-1β (Il-1β). Also, MMF administration significantly decreased Con A-induced increase in the immune-expression of pro-apoptotic Bcl-2-associated X protein (Bax) and markedly increased Con A-induced decrease in the anti-apoptotic B-cell lymphoma 2 protein (Bcl2).. The observed ameliorative effect of MMF against Con A-induce ALI may be contributed to its anti-inflammatory, anti-oxidant and anti-apoptotic potentials taking into consideration that TLR4/NF-κB and Nrf2/HO-1 are the main implicated pathways. Schematic diagram summarizing the possible mechanisms underlying the ameliorative potential of Mycophenolate Mofetil against Con A-induced acute liver injury. Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2, MMF Mycophenolate mofetil, Con A Concanavalin A, GSH reduced glutathione, HO-1 Heme oxygenase-1, IL-1β Interleukin-1β, IFN-γ Interferon-γ, MDA Malondialdehyde, NF-κB Nuclear Factor Kappa B, Nrf2 Nuclear factor erythroid 2-related factor 2, NO Nitric Oxide, SOD Superoxide Dismutase, TLR4 Toll-like receptor 4, TNF-α tumor necrosis factor-α.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Enzyme Inhibitors; Heme Oxygenase-1; Male; Membrane Proteins; Mice; Mycophenolic Acid; NF-E2-Related Factor 2; NF-kappa B; Signal Transduction; Toll-Like Receptor 4

Selenium nanoparticles (SeNPs) have attracted wide attention for their use in nutritional supplements and nanomedicine applications. However, their potential to protect against autoimmune hepatitis has not been fully investigated, and the role of their antioxidant capacity in hepatoprotection is uncertain. In this study, chitosan-stabilized SeNPs (CS-SeNPs) were prepared by means of rapid ultra-filtration, and then their antioxidant ability and free-radical scavenging capacity were evaluated. The hepatoprotective potential of a spray-dried CS-SeNPs powder against autoimmune liver disease was also studied in the concanavalin A (Con A)-induced liver injury mouse model. CS-SeNPs with size of around 60 nm exhibited acceptable oxygen radical absorbance capacity and were able to scavenge DPPH, superoxide anion, and hydroxyl radicals. The CS-SeNPs powder alleviated Con A-caused hepatocyte necrosis and reduced the elevated levels of serum alanine transaminase, aspartate transaminase, and lactic dehydrogenase in Con A-treated mice. These results suggest that the CS-SeNPs powder protected the mice from Con-A-induced oxidative stress in the liver by retarding lipid oxidation and by boosting the activities of superoxide dismutase, glutathione peroxidase, and catalase, partly because of its ability to improve Se retention. In conclusion, SeNPs present potent hepatoprotective potential against Con A-induced liver damage by enhancing the redox state in the liver; therefore, they deserve further development.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Chitosan; Concanavalin A; Disease Models, Animal; Free Radical Scavengers; Glutathione Peroxidase; Liver; Male; Mice; Nanoparticles; Oxidation-Reduction; Oxidative Stress; Powders; Reactive Oxygen Species; Selenium; Spray Drying; Superoxide Dismutase

Acute liver failure is a serious disease caused by a variety of factors, and immunological injury is an important pathological process. Comprehensive liver treatment efficacy is poor, and the mortality rate is high. Magnesium isoglycyrrhizinate (MgIG) is a new glycyrrhizin drug extracted from the traditional Chinese medicine licorice. The mechanism by which MgIG regulates ConcanavalinA (ConA)-induced immunological liver injury in mice is not completely clear.. Immunological liver injury was induced in mice by ConA injection, and the inflammatory macrophages model was induced by lipopolysaccharide (LPS). MgIG was administered 30 min prior to ConA and LPS treatment. The mice in the different groups were sacrificed 12 h after treatment, and macrophages were measured at 30 min, 1 h, and 2 h after induction. Macrophages, liver, and blood samples were then collected for analysis.. After drug administration, the MgIG group showed a marked decrease in serum transaminase levels, reduced apoptosis and hepatic inflammatory responses compared to the ConA group. Furthermore, there was a significant reduction in inflammatory cytokine levels in the serum and liver tissue.. These findings demonstrated that MgIG protects against ConA-induced immunological liver injury by markedly alleviating liver inflammation, and this provides guidance for the clinical amelioration of liver inflammation induced by immunological factors.

Topics: Animals; Apoptosis; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; JNK Mitogen-Activated Protein Kinases; Liver; Macrophages; Male; Mice, Inbred BALB C; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Saponins; Signal Transduction; Triterpenes

Amphiregulin (Areg), a glycoprotein from the epidermal growth factor receptor (EGFR) ligand family, has a well-documented protective role against tissue injury; however, its effects on immune-mediated liver injury are still unclear. Here, we used a concanavalin A (ConA)-induced acute liver hepatitis model to explore the effects of Areg on immune-mediated acute liver injury.. Some C57BL/6 mice were administered ConA at a dose of 20 mg/kg (model mice), and some received 5 µg of Areg (treated mice). Then, their survival rates over 36 h were analyzed. After 5 h of treatment, liver function, hepatic histology, and apoptosis in liver tissue were investigated, and cytokine expression and neutrophil infiltration and activity in the liver were detected. Moreover, the protective effects of Areg were also evaluated without IL-22. Our results showed that Areg administration increased acute liver failure (ALF) mouse survival, restored liver function, and alleviated liver damage. Interestingly, Areg administration increased IL-22 production in hepatic T cells and upregulated IL-22 concentrations in the serum and liver, whereas IL-22 neutralization completely abolished the therapeutic effect of Areg. Meanwhile, Areg administration was concomitant with increased expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, which are important in the hepatoprotective mechanism of IL-22.. Areg showed direct protective effects against ConA-induced acute liver injury, which suggests the potential therapeutic application of Areg in immune-mediated ALF.

Topics: Amphiregulin; Animals; Apoptosis; bcl-X Protein; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Interleukin-22; Interleukins; Liver; Liver Failure, Acute; Mice, Inbred C57BL; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; STAT3 Transcription Factor; T-Lymphocytes

A nucleoside analog, 4'-cyano-2'-deoxyguanosine (CdG), which was developed as an inhibitor of the chronic hepatitis B virus (HBV), exhibited a superior antiviral activity against both wild-type and drugs-resistant HBV to marketed nucleoside analogs. In addition to previous pharmacokinetic studies of CdG in healthy rats, this study reports on an evaluation of the pharmacokinetic characteristics of CdG in a rat model of viral liver injury (VLI) induced by treatment with concanavalin A. Following an intravenous administration of CdG at a dose of 1 mg/kg, the plasma concentration profile of CdG in VLI model rats was found to be similar to that of healthy rats with no significant difference in kinetic parameters. However, when CdG was orally administered at a dose of 1 mg/kg, the maximum blood concentration was much lower in VLI model rats than in healthy rats. Interestingly, the amount of residual food in the stomachs in VLI model rats was significantly larger than that in healthy rats, indicating that the adsorption of CdG in the gastrointestinal tract was inhibited in the presence of food as well as other marketed nucleoside analogs. As observed in healthy rats, CdG was largely distributed to the liver compared to the kidney in the VLI model. These results suggest that liver pathology has only a minor effect on the pharmacokinetic properties of CdG, but the influence of food on CdG absorption needs to be considered.

Topics: Administration, Intravenous; Animals; Antiviral Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Deoxyguanosine; Disease Models, Animal; Drug Evaluation, Preclinical; Food-Drug Interactions; Gastrointestinal Absorption; Hepatitis B, Chronic; Humans; Liver; Male; Rats

Topics: Animals; Aspergillus; CD28 Antigens; CD3 Complex; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Diketopiperazines; Humans; Liver; Male; Mice; Mice, Inbred BALB C; Molecular Structure; Oxepins; Piperazines; Spleen; T-Lymphocytes; X-Ray Diffraction

Concanavalin A (ConA)-induced liver damage of mice is a well-established murine model mimicking the human autoimmune hepatitis (AIH). However, the pathogenic genes of the liver injury remain to be revealed.. Using time-series liver transcriptome, top dynamic genes were inferred from a set of segmented regression models, and cross-checked by weighted correlation network analysis (WGCNA). AIH murine models created by ConA were used to verify the. We identified 115 top dynamic genes, of which most were overlapped with the hub genes determined by WGCNA. The expression of several top dynamic genes including. We have identified the top dynamic genes related to the process of acute liver injury, and highlighted a targeted strategy for

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Databases, Genetic; Disease Models, Animal; Gene Expression Profiling; Gene Regulatory Networks; Liver; Male; Mice, Inbred C57BL; Tetraspanin 30; Time Factors; Transcriptome

Immune mediated liver injury includes activation of different immune pathways that requires various modalities to control their consequences. The current study involves evaluation of retinoic acid (RA) modulatory effects on immune responses induced in concanavalin A (ConA) model of acute hepatitis.. Mice were divided as follows: Control group; RA group: received 35 mg/kg RA; ConA group: received 15 mg/kg ConA; ConA + RA group: received ConA and RA as described. Liver function biomarkers were measured in addition to malondialdehyde as lipid peroxidation biomarker. Liver tissue sections were scored for necro-inflammation, neutrophils infiltration, CD4+ T cells infiltration and NF-κb positive cells. Effect on hepatic levels of TNF-α, IL-4, IL-10 and MCP-1 was evaluated as well.. Injection of RA before ConA significantly (p < 0.001) decreased ALT, AST and LDH levels compared to their levels in ConA group. Hepatic infiltration of neutrophils and CD4+ T cells was markedly (p < 0.001) reduced by RA. Hepatic injury, necrosis and expression of NF-κb were significantly decreased by RA when injected before ConA challenge. A significant decrease in the measured cytokines TNF-α and IL-4 was observed in ConA + RA group in addition to a decrease in MCP-1 level. On the other hand, IL-10 was significantly increased in the latter group compared to ConA group.. RA can protect against ConA-induced hepatitis through: interrupting early inflammatory response as neutrophils, monocytes and CD4+ T cells infiltration, modulating IL-4 level and subsequent production of TNF-α and NF-κb activation, mitigating second inflammatory responses through increasing IL-10 liver production.

Topics: Animals; Anti-Inflammatory Agents; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Hepatitis; Liver; Male; Mice, Inbred BALB C; Neutrophils; NF-kappa B; Signal Transduction; Tretinoin

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; bcl-2-Associated X Protein; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Cytoprotection; Glutathione; Hepatocytes; Male; Malondialdehyde; Mice; Mice, Inbred ICR; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Sterols; Superoxide Dismutase; Taraxacum; Toll-Like Receptors; Transcription Factor RelA; Triterpenes; Tumor Necrosis Factor-alpha

Glycyrrhizic acid ammonium salt (GAAS) is derived from glycyrrhizic acid, which is an active compound extracted from the Chinese traditional medicine licorice. GAAS is clinically applied to treat immune-mediated liver injury, but its mechanism remains elusive. Therefore, this study aimed to investigate the mechanism in which GAAS alleviates immune-mediated liver injury induced by Concanavalin A (ConA). After ten days of intragastric administration of GAAS, 20 mg/kg ConA was injected via tail vein to establish the immune-mediated liver injury model of BALB/C mice. Then, the concentrations of ALT, AST, and TBIL in the serum of mice were determined. H&E staining was performed to observe the pathological changes in the liver, and the expression of liver cytokines was detected by qPCR. Immunohistochemistry and Western blot analysis was employed to detect the expression of liver-related proteins. The apoptosis in liver tissue was detected by TUNEL. Our results suggest that GAAS demonstrated excellent protective effects in the liver. We found that GAAS down-regulated the mRNA expression of IL-1β, IL-6, TNF-α, IFN-γ, and IL-17A, and it up-regulated the mRNA expression of IL-4 and TGF-β. Additionally, GAAS may modulate the balance of four immune cells (Th1, Th2, Th17, and Treg) by regulating the expression of T-bet, GATA3, RORγt, and Foxp3 to alleviate liver injury in mice. Furthermore, GAAS decreased hepatocyte apoptosis by blocking the JAK1/STAT1/IRF1 pathway, suppressing oxidative stress, decreasing p-JNK expression, and regulating the expression of apoptosis-related proteins. In summary, the mechanism of GAAS in liver injury alleviation acts to regulate the balance of Th cells in the liver to inhibit hepatocyte apoptosis. This study may provide a new strategy for the treatment of immune-mediated liver injury.

Topics: Ammonium Compounds; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Down-Regulation; Glycyrrhizic Acid; Hepatocytes; Liver; Male; Mice; Mice, Inbred BALB C; T-Lymphocyte Subsets; Up-Regulation

The considerable variability of responses amongst subjects to disease triggers and immunotherapies is a major obstacle to designing better immune-based therapies. Therefore, development of patient-tailored precision medicine that improves the efficacy of immunomodulatory drugs is necessary. The individualized response to disease triggers and immunomodulatory therapies was studied using the concanavalin A (ConA) immune-mediated hepatitis model and the oral administration of anti CD3 or β-glucosylceramide (GC). Mice were treated with anti-CD3 antibodies or GC followed by an injection of ConA. The effects of these treatments on liver damage and the immune profile were then analyzed. An individualized response to ConA and orally administered immunomodulatory agents was observed in eight consecutive experiments. While alleviation of the immune-mediated liver injury, as measured by serum levels of liver enzymes, was seen, and high intra-group and inter-experimental variabilities were detected. A similar individualized response was observed for the effect on serum levels of IFN-γ, TNF-α, and IL-10 and on CD4+CD25+, CD8+CD25+, and CD3+NK1.1+ lymphocytes. A personalized form of inherent randomness in an isolated system was documented, which may underlie the variability in responses to immune triggers and immunomodulatory therapies. The data support the use of personalized randomness-based platforms for improving the response to chronic therapies.

Topics: Animals; Antibodies; Antigens, CD; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Immunologic Factors; Immunomodulation; Liver; Male; Mice

Diammonium glycyrrhizinate (DG) is a replacement for glycyrrhizic acid, which is used as a hepatic protector in clinical practice for most liver diseases. The potential role of immune response during autoimmune hepatitis-induced by concanavalin A (Con A)-remains to be elucidated.. C57BL/6J mice were treated with two different doses of DG (75 and 200 mg/kg) 2 hrs before administering Con A. The mice were sacrificed after administering Con A for 0, 6, and 24 hrs. Liver damage grade and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin levels were evaluated. The expression level of cleaved-caspase 3 in liver was detected by Western blotting. Inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin-6 (IL-6), and interferon γ (IFN-γ) in liver were detected by RT-PCR. Thymus, peripheral blood, spleen, and liver tissues were collected to analyze the percentages of NKT cells, subsets of CD4. Our results revealed that DG pre-treatment significantly decreased the serum ALT and AST levels and improved the histological damage in Con A-induced autoimmune liver injury. Pre-treatment with DG down-regulated the inflammatory cytokines upon challenge with Con A. The DG pre-treatment inhibited the apoptosis of T lymphocytes in the thymus. Further, it effectively suppressed the proliferation of CD4. We believe that the potential protective effect of DG against Con A-induced hepatitis may be partially attributed to its inhibitory activities on inflammatory cytokines in the livers, lymphocyte apoptosis in the thymus, NKT cells proliferation, and activation of CD8

Topics: Animals; Anti-Inflammatory Agents; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Glycyrrhizic Acid; Hepatitis, Autoimmune; Male; Mice; Mice, Inbred C57BL; Molecular Structure; Natural Killer T-Cells; Structure-Activity Relationship; T-Lymphocytes, Regulatory

The purpose of this study was to explore the protective effect of protopanaxatriol (PPT) on acute liver injury induced by concanavalin A (ConA). In this study, mice were randomly separated into four groups. The first group received PBS (i.v.). The second group was given PPT (50 mg/kg body weight, i.p.) for 3 days before PBS (i.v.) injection. The third group received ConA (15 mg/kg body weight, i.v.). The fourth group was administered PPT (50 mg/kg body weight, i.p.) for 3 days before ConA (i.v.) injection. The serum levels of ALT and AST were detected after 20 h of ConA injection. The pathological changes of liver were observed by H/E staining. The expression of inflammatory factors was measured by ELISA and qRTPCR, and the changes of the signaling pathway were detected by western blot. Histopathological changes and blood transaminase elevation indicated significant liver injury after ConA injection. However, PPT pretreatment obviously reversed these changes. The ELISA and qRT-PCR results indicated that PPT preconditioning significantly inhibited the production of inflammatory factors. In addition, this inhibitory effect of PPT was mainly mediated by regulation of the nuclear factor-κB (NF-κB) signaling pathway. The active ingredient of ginseng, PPT, exerts an obvious protective effect on acute liver injury caused by ConA through inhibiting the inflammatory response.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Liver; Male; Mice, Inbred C57BL; Protective Agents; Sapogenins

Previous studies showed that CD4. Opposing to the previous results obtained in wild-type mice, transferred CD4

Topics: Animals; CD8-Positive T-Lymphocytes; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; DNA-Binding Proteins; Immunity, Innate; Lymph Nodes; Lymphocytes; Male; Mice, Inbred C57BL; Mice, Knockout; Spleen

The relationship between hepatoprotective effects of selenium-biofortified corn (Zea mays Linn) peptides (SeCPs) and its antioxidant ability was evaluated and the structure of SeCPs was identified. SeCPs and corn peptides (CPs) both had good antioxidant ability, and the effect of SeCPs was significantly higher than CPs within a certain concentration range (P < 0.05). Additionally, animal experiments indicated that SeCPs (200 mg/kg) had a significantly protective effect against concanavalin A (Con A) induced hepatic lesions, as it significantly declined glutamic-pyruvic transaminase (AST), alanine transaminase (ALT) activities, tumor necrosis factor alpha (TNF-α), interferon (IFN)-γ contents in serum, and malondialdehyde (MDA) contents in liver (P < 0.05). Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities in liver were also significantly increased by SeCPs (P < 0.05). The amino acid composition of SeCPs with Mw < 1 kDa was mainly glutamic acid (Glu, 31.18%), leucine (Leu, 21.06%) and alanine (Ala, 13.26%). According to the retention time, the amino acid sequences of 8 selenium-biofortified corn peptides and 29 selenium-free corn peptides were identified. Our results illustrated that the mechanisms of SeCPs against Con A induced hepatic injury in mice may be related to its antioxidant ability and reduction of lipid peroxidation, inhibiting the release of immune factors, such as TNF-α and IFN-γ.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Dose-Response Relationship, Drug; Liver; Male; Mice; Mice, Inbred BALB C; Peptides; Protective Agents; Selenium; Zea mays

8:2 Fluorotelomer alcohol (8:2 FTOH) is widely used in houseware and industrial goods and is ubiquitous in the surrounding environment. 8:2 FTOH has been linked to hepatoxicity, nephrotoxicity, and reproductive toxicity, as well as endocrine-disrupting effects. However, as of yet, the research regarding immunotoxicity of 8:2 FTOH remains largely limited. In the present study, adult male C57BL/6 mice were administered with 10, 30, and 100 mg/kg/d 8:2 FTOH by gavage for 28 days to investigate its immunotoxicity in vivo. The results showed that exposure to 8:2 FTOH caused increases in liver weight and histological changes in the liver, including vacuolation, cell swelling, immune cell infiltration, karyopyknosis and nuclear swelling. No histological change in either the spleen or the thymus was observed after administration of 8:2 FTOH. In addition, exposure to 8:2 FTOH reduced the concentration of IL-1β in serum, and mRNA levels of IL-1β, IL-6, and TNF-α in both the thymus and spleen. CXCL-1 mRNA expression was downregulated in both the liver and thymus after 8:2 FTOH administration, while only IL-1β mRNA expression was upregulated in the liver. Moreover, the exposure of primary cultured splenocytes to 8:2 FTOH inhibited the ConA-stimulated proliferation of splenocytes at concentrations of 30 and 100 μM, and the LPS-stimulated proliferation of splenocytes at 100 μM. Furthermore, 8:2 FTOH inhibited the level of secreted IFN-γ in ConA-stimulated splenocytes. The results obtained in the study demonstrated that 8:2 FTOH posed potential immunotoxicity and liver injury in mice. Our findings will provide novel data for the health risk assessment of 8:2 FTOH.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Dose-Response Relationship, Drug; Environmental Pollutants; Fluorocarbons; Liver; Male; Mice; Mice, Inbred C57BL; RNA, Messenger; Spleen

Glycyrrhizin, a triterpenoid compound, has been reported to be an anti-inflammatory agent for the treatment of a variety of inflammatory diseases including hepatitis. However, the mechanism by which glycyrrhizin inhibits inflammation is unclear. Using a Con A-induced hepatitis model in mice, we found that administration of glycyrrhizin ameliorates Con A-induced liver injury, which manifests as reduction in the production of inflammatory cytokines IFN-γ, IL-6 and IL-17, as well as serum alanine aminotransferase (ALT). Blockade of IL-17 dramatically mitigates liver injury resulting from Con A challenge. Interestingly, at both the mRNA and protein levels, the endogenous alarmin inflammatory molecule high-mobility group box 1 (HMGB1) is significantly decreased in mice injected with glycyrrhizin combined with Con A compared to those injected with Con A alone. In contrast, the administration of glycyrrhizin with Con A challenge up-regulates the production of IL-25. Furthermore, an increase in the proportion of protective lymphocyte subset, Gr-1

Topics: Animals; Anti-Inflammatory Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Glycyrrhizic Acid; Hepatitis; Interleukin-17; Interleukins; Male; Mice; Mice, Inbred C57BL

Acute liver failure (ALF) is a serious threat to the life of people all over the world. Finding an effective way to manage ALF is important. Human liver stem cells (HLSCs) are early undifferentiated cells that have been implicated in the regeneration and functional reconstruction of the liver. In this study, we aimed to evaluate the protective effects of the HLSC line HYX1 against concanavalin A (ConA)-induced acute liver injury.. HYX1 cells were characterized by microscopy, functional assays, gene expression, and western blot analyses. We showed that HYX1 cells can differentiate into hepatocytes. We intraperitoneally injected HYX1 cells in mice and administered ConA via caudal vein injection 3, 6, 12, 24, and 48 h later. The effects of HYX1 cell transplantation were evaluated through blood tests, histology, and flow cytometry.. HYX1 cells reduced the levels of alanine transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) in serum and dramatically decreased the severity of liver injuries. Mechanistically, HYX1 cells promoted myeloid-derived suppressor cell (MDSC) migration into the spleen and liver, while reducing CD4. These results confirm the efficacy of HLSCs in the prevention of the ConA-induced acute liver injury through modulation of MDSCs and CD4

Topics: Animals; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Hepatocytes; Humans; Interferon-gamma; Liver; Mice; Myeloid-Derived Suppressor Cells; Spleen; Stem Cell Transplantation; Stem Cells; Tumor Necrosis Factor-alpha

Topics: Animals; Apoptosis; Blotting, Western; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Line; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Flow Cytometry; Glycosides; Humans; Immunohistochemistry; Mice; Vincetoxicum

Cannabinoid receptor 2 (CB2R) is highly expressed in immune cells and plays an important role in regulating immune responses. In the current study, we investigated the effects of GW405833 (GW), a specific CB2R agonist, on acute liver injury induced by concanavalin A (Con A). In animal experiments, acute liver injury was induced in mice by injection of Con A (20 mg/kg, i.v.). The mice were treated with GW (20 mg/kg, i.p., 30 min after Con A injection) or GW plus the selective CB2R antagonist AM630 (2 mg/kg, i.p., 15 min after Con A injection). We found that Con A caused severe acute liver injury evidenced by significantly increased serum aminotransferase levels, massive hepatocyte apoptosis, and necrosis, as well as lymphocyte infiltration in liver tissues. Treatment with GW significantly ameliorated Con A-induced pathological injury in liver tissue, decreased serum aminotransferase levels, and decreased hepatocyte apoptosis. The therapeutic effects of GW were prevented by AM630. In cell experiments, we showed that CB2Rs were highly expressed in Jurkat T cells, but little expression in L02 liver cells. Treatment with GW (10-40 μg/mL) dose-dependently decreased the viability of Jurkat T cells and induced cell apoptosis, which was reversed by AM630. In the coculture of Jurkat T cells with L02 liver cells, GW dose-dependently protected L02 cells from apoptosis induced by Con A (5 μg/mL). The protective effect of GW was reversed by AM630 (1 μg/mL). Our results suggest that GW protects against Con A-induced acute liver injury in mice by inhibiting Jurkat T-cell proliferation through the CB2Rs.

Topics: Animals; Apoptosis; Cannabinoid Receptor Agonists; Cell Line, Tumor; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Humans; Indoles; Liver; Male; Mice, Inbred BALB C; Morpholines; Protective Agents; Receptor, Cannabinoid, CB2; T-Lymphocytes

Sancao granule (SCG) is a traditional Chinese herb formula, which has been used for autoimmune liver disease for decades. Previous study demonstrated that there was an exactly therapeutic effect of SCG on autoimmune hepatitis (AIH) by improving liver function and alleviating the clinical symptoms. However, studies of the mechanism by which SCG alleviates Con A-induced liver injury (CILI) should be complemented.. An ultraperformance liquid chromatography with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS)-based metabolomics approach combined with principle component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) were integrated applied to obtain metabolites for clarifying mechanisms of disease.. In accordance with previously study, the present study demonstrated that SCG could obviously improve the liver injury in mouse induced by Con A via downregulating serum biochemical indexes, alleviating the histological damage and inhibiting the neutrophil infiltration in liver tissues. Different expression of 9 metabolites related to 8 pathways, including fatty acid biosynthesis, arachidonic acid metabolisms, linoleic acid metabolisms, sphingolipid metabolisms, fatty acid elongation in mitochondria, glycerophospholipid metabolism, fatty acid metabolism, pyrimidine metabolism were demonstrated responsible for the efficacy of SCG in treating CILI.. In sum up, SCG has been indicated favorable therapeutic effect on Con A induced liver injury. And metabolomics could be a promising approach, which provide insights into mechanisms of SCG in treating CILI.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Liver; Male; Metabolomics; Mice; Mice, Inbred BALB C; Protective Agents

The protective effects of G protein-coupled receptor 39 (GPR39) on concanavalin A (Con A)-induced hepatitis in mice was examined. In a dose dependent manner and at 24 h after the elicitation by Con A, oral administration of TC-G 1008, a GPR39 agonist, reduced both, the glutamic-pyruvic transaminase levels (a marker for liver injury) and the necrosis area, as revealed by the histological analysis of tissues from mice with Con A-induced hepatitis. TC-G 1008 also suppressed serum interleukin (IL)-6 and tumor necrosis factor (TNF)-α significantly at 6 h after the elicitation, suggesting that the cells producing IL-6 and/or TNF-α are the targets of TC-G 1008. One potential target cell appears to be a monocyte-derived macrophages because TC-G 1008 treatment suppressed lipopolysaccharide-induced IL-6 production from U937 macrophages in vitro. Taken together, GPR39 agonist TC-G 1008 ameliorates liver injury in the Con A model by blocking pro-inflammatory cytokine production. Use of GPR39 agonists for monotherapy or in combination with immunosuppressants might prove to be beneficial in the treatment of autoimmune hepatitis.

Topics: Animals; Cell Culture Techniques; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis; Humans; Imidazoles; Interleukin-10; Interleukin-6; Liver; Male; Mice; Mice, Inbred C57BL; Models, Animal; Pyrazoles; Pyridazines; Pyrimidines; Receptors, G-Protein-Coupled; Sulfonamides; Tumor Necrosis Factor-alpha; U937 Cells

GPBAR1, also known as TGR5, is a G protein-coupled receptor activated by bile acids. Hepatic innate immune cells are involved in the immunopathogenesis of human liver diseases and in several murine hepatitis models. Here, by using genetic and pharmacological approaches, we provide evidence that GPBAR1 ligation attenuates the inflammation in rodent models of hepatitis.. Hepatitis was induced by concanavalin A (Con A) or α-galactosyl-ceramide (α-GalCer). 6b-Ethyl-3a,7b-dihydroxy-5b-cholan-24-ol (BAR501), a selective agonist of GPBAR1, was administrated by o.s.. In the mouse models of hepatitis, the genetic ablation of Gpabar1 worsened the severity of liver injury and resulted in a type I NKT cells phenotype that was biased toward a NKT1, a proinflammatory, IFN-γ producing, NKT cells subtype. Further on, NKT cells from GPBAR1. Present results illustrate a role for GPBAR1 in regulating liver NKT ecology. Because NKT cells are an essential component of liver immune system, our data provide a compelling evidence for a GPBAR1-IL-10 axis in regulating of liver immunity.

Topics: Animals; Cell Line; Chemical and Drug Induced Liver Injury; Cholestanols; Concanavalin A; Disease Models, Animal; Galactosylceramides; Hep G2 Cells; Hepatitis; Humans; Interleukin-10; Male; Mice; Natural Killer T-Cells; RAW 264.7 Cells; Receptors, G-Protein-Coupled

CD160 and BTLA both bind to herpes virus entry mediator. Although a negative regulatory function of BTLA in natural killer T (NKT) cell activation has been reported, whether CD160 is also involved is unclear. By analyzing CD160

Topics: Animals; Antigens, CD; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Galactosylceramides; GPI-Linked Proteins; Liver; Lymphocyte Activation; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Receptors, Immunologic; Receptors, Tumor Necrosis Factor, Member 14; Survival Analysis

The present study was performed to investigate the effect of Aesculus hippocastanum (AH; Venoplant®) on concanavalin A (ConA)-induced acute liver injury and explore the mechanism in mice.. ConA (20 mg/kg) was administered via tail vein injection to induce hepatic damage. The groups of AH (Venoplant®) were given at 65.8, 131.6, and 263.2 mg/kg by oral gavages for 20 days. The serum levels of aspartate transaminase (AST), alanine aminotransferase (ALT), total protein (TP), and albumin (Alb) were determined by automatic biochemical analyzer, and the Alb/globulin (A/G) ratio was calculated. Tumor necrosis factor-α (TNF-α) and IFN-γ levels were assayed by enzyme-linked immunosorbent assay. The liver tissue was attained by hematoxylin and eosin, and the histopathological changes were calculated. The cell apoptosis was assayed by terminal dUTP nick-end labeling. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) content of liver tissue were assayed by related kits. The activity of caspase-3 was detected by spectrophotometry. The expressions of cytochrome c, Bax, Bcl-2, c-Jun N-terminal kinase (JNK), and p-JNK were detected by western blot.. The results showed that the levels of ALT, AST, IFN-γ, and TNF-α in AH (Venoplant®) groups were significantly lower than those in ConA-injured group, while the levels of TP, Alb, and A/G were significantly higher. The SOD and GSH levels were significantly increased, and the MDA level was decreased; liver histopathology was changed consistently with the serological indicators, AH (Venoplant®) treatment significantly reduced the pathological damage and cell apoptosis; while in AH (Venoplant®) group, the expressions of cytochrome c, caspase-3, Bax/Bcl-2 ratio, and p-JNK were significantly decreased.. AH (Venoplant®) could significantly protect the ConA-induced acute liver injury in mice via inhibition of reactive oxygen species and JNK pathway.

Topics: Aesculus; Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Caspase 3; Chemical and Drug Induced Liver Injury; Concanavalin A; Glutathione; In Situ Nick-End Labeling; JNK Mitogen-Activated Protein Kinases; Liver; Male; Malondialdehyde; Mice; Oxidative Stress; Protective Agents; Proto-Oncogene Proteins c-bcl-2; Reactive Oxygen Species; Superoxide Dismutase

1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG), a chemically synthesized monoacetyldiaglyceride, is one of the constituents in Sika deer antlers and has been known traditionally as having immunomodulatory effects. However, the mechanism by which PLAG controls neutrophil migration, which evokes liver injury in the hepatitis animal model, remains largely unknown. This study was designed to evaluate the immunomodulatory effects of PLAG on cytokine secretion and neutrophil migration in vivo and in vitro. Concanavalin A (Con A) induced leukocyte infiltration in the liver and increased plasma cytokine levels. Pretreatment with PLAG reduced the levels of interleukin (IL)-4, IL-6, IL-10, and CXCL2, but maintained interferon (IFN)-γ levels and modulated neutrophil recruitment toward the liver. Furthermore, the mRNA and protein levels of IL-4 and CXCL2 in liver tissue were also decreased in the Con A-treated mice. Liver histology analyses showed that PLAG reduced Con A-induced hepatic necrosis, which was accompanied by leukocyte infiltration. The in vitro studies revealed that PLAG reduced IL-4 secretion in Con A stimulated T cell and blocked signal transducer and activator of transcription 6 (STAT6) Con A induced hepatocyte. PLAG attenuated IL-4 induced activation of atypical protein kinase C (PKC)/STAT6 in hepatocytes and inhibited neutrophil migration toward the liver tissue through suppression of IL-8/vascular cell adhesion molecule (VCAM) expression. These results suggest that PLAG could mitigate excess neutrophil migration into liver tissue and potentially have a therapeutic effect on immune-mediated liver injury.

Topics: Animals; Cell Line, Tumor; Chemical and Drug Induced Liver Injury; Chemokine CXCL2; Concanavalin A; Cytokines; Diglycerides; Disease Models, Animal; Gene Expression Regulation; Hep G2 Cells; HL-60 Cells; Humans; Interleukin-10; Interleukin-4; Interleukin-6; Male; Mice

Roots of Sophora flavescens is an important herbal medicine for treatment of HBV and hepatic carcinoma in China. Alkaloids in the root were well known for exhibiting good hepato-protective and anti-HBV effects. However, polysaccharides as main components in the root remained unknown. In the studies, we investigated the chemical features and hepatoprotective effects of Sophora flavescens polysaccharides (SFP-100 and its active fractions) with ConA-induced hepatitis mice, human liver LO2 cells and HepG2.2.15 cells. The results showed that SFP-100 was composed of arabinose, glucose, galactose and galacturonic acid, SFP-100-A mainly contained glucose. SFP-100-B and SFP-100-C were acidic polysaccharides. SFP-100 significantly decreased hepatocytes apoptosis, inhibited the infiltration of neutrophils and macrophages into liver, and improved the production of IFN-γ and IL-6 of splenocytes in ConA-induced hepatitis mice. SFP-100 and its two sugar fractions increased LO2 cell proliferation and reduced cell apoptosis induced by ConA. SFP-100, SFP-100-A and SFP-100-C remarkedly inhibited the secretion of HBsAg and HBeAg by HepG2.2.15 cells.These results suggested Sophora flavescens polysaccharides exerts significant hepatoprotective and anti-HBV roles, and further is used for treatment of immune-mediated liver disease in the future.

Topics: Animals; Antiviral Agents; Body Weight; Cell Proliferation; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Female; Hepatitis B; Hepatitis B virus; Hepatocytes; Lymphocytes; Mice; Organ Size; Plant Extracts; Plant Roots; Polysaccharides; Protective Agents; Sophora

The scavenger receptor CD36 recognizes a diverse set of ligands and has been implicated in a wide variety of normal and pathological processes, including lipid metabolism, angiogenesis, atherosclerosis, and phagocytosis. In particular, recent findings have demonstrated its crucial functions in sterile inflammation and tumor metastasis. However, the role of CD36 in immune-mediated hepatitis remains unclear. Concanavalin A (ConA)-induced liver injury is a well-established experimental T cell-mediated hepatitis. To understand the role of CD36 in hepatitis, we tested the susceptibility of CD36-deficient (CD36. Our findings suggest that CD36 plays an important proinflammatory role in ConA-induced liver injury by promoting hepatic inflammation and mediating the proapoptotic effect of chemokine CXCL10, and therefore, may be a potential therapeutic target for immune-mediated hepatitis. (Hepatology 2018;67:1943-1955).

Topics: Animals; Apoptosis; Blood Platelet Disorders; CD36 Antigens; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Concanavalin A; Cytokines; Disease Models, Animal; Flow Cytometry; Genetic Diseases, Inborn; Genistein; Hepatitis; Hepatocytes; Liver; Mice; Mice, Inbred C57BL; Signal Transduction

Jiang-Xian HuGan (JXHG) formulated by five natural products including Freshwater clam (Corbicula fluminea), Curcuma longa L., Ligustrum lucidum, Eclipta prostrata (L.) L. and Paeonia lactiflora Pall., has exhibited a great hepatoprotective effect.. We investigated the effect of JXHG on concanavalin A (ConA)-induced acute live injury in mice, and to elucidate its underlying molecular mechanisms.. Jiangkanling Capsule (900 mg/kg), low-dose JXHG (LJXHG, 700 mg/kg), high-dose JXHG (HJXHG, 1400 mg/kg) were administered to mice by oral gavage daily for 20 days prior to a single intravenous injection of ConA (20 mg/kg). Liver injury was evaluated by measuring the serum levels of enzymes and cytokines as well as liver histological analysis. We also measured the hepatic expression of cytokines at mRNA levels and the proteins related to NF-κB and Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathways.. Our results showed that JXHG pretreatment significantly alleviated ConA-induced live injury as evidenced by decreased serum levels of glutamic-pyruvic transaminase (ALT) and glutamic oxalacetic transaminase (AST), and reduced hepatocyte apoptosis and mortality. Furthermore, JXHG was able to significantly reduce the serum levels of proinflammatory cytokines, down-regulate the mRNA expression of interleukin-6 (IL-6) and interferon-γ (IFN-γ), and up-regulate IL-10 as well as superoxide-dimutase-1 (SOD1), glutathione reductase (GSR) and Glutathione peroxidase 2 (GPX2) mRNA in the liver tissues after Con A injection. In addition, JXHG pretreatment dramatically suppressed the phosphorylation of NF-κB p65 (p65), increased Nrf2 expression, and decreased the expression ratio of cleaved caspase-3/caspase-3 in liver tissues.. These results suggest that JXHG protects against ConA-induced acute live injury through inhibiting NF-κB mediated inflammatory pathway and promoting Nrf2 mediated anti-oxidative stress signaling pathway.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Curcumin; Cytokines; Disease Models, Animal; Drugs, Chinese Herbal; Enzymes; Inflammation Mediators; Liver; Male; Mice, Inbred BALB C; NF-E2-Related Factor 2; NF-kappa B; Oleanolic Acid; Oxidative Stress; Signal Transduction

We have previously demonstrated the hepatoprotective effect of dihydroquercetin (DHQ) against concanavalin A (Con A)-induced immunological hepatic injury in mice. In this study, we investigated the immunoregulatory effects of DHQ on Con A-induced liver injury in mice. DHQ administration significantly decreased the serum levels of alanine transaminase and aspartate transaminase, effectively prevented liver damage, and increased the survival rate of Con A-treated mice. Immunohistochemistry examination revealed that supplementation with DHQ obviously reduced infiltration of CD4+ and CD8+ T cells in the injured liver tissues. Furthermore, DHQ administration resulted in down-regulation of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-4, and IL-10), the chemokine osteopontin, apoptosis factors (Fas and FasL), transcription factors that regulate Th cell differentiation (T-bet and GATA-3), perforin, granzyme B, and inducible nitric oxide synthase (iNOS). In vitro, treatment with DHQ protected HepG2 cells against TNF-α/ActD-induced apoptosis by inhibiting the activation of caspase-3, caspase-7, and caspase-8. In addition, DHQ reduced phosphorylation of NF-kB/p65, and inhibited the expressions of pro-apoptotic factors (p53 and Bax), while it up-regulated the expression of the anti-apoptotic factor Bcl-2. Our findings suggest that the immunosuppressive effects of DHQ ameliorated Con A-mediated immunological liver injury by reducing the expression of pro-inflammatory mediators and infiltration of CD4+ and CD8+ T cells in liver tissues, and DHQ protected HepG2 cells against TNF-α/ActD-induced apoptosis possibly via modulation of the caspase and NF-kB pathways.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Hep G2 Cells; Humans; Interleukin-10; Interleukin-2; Liver; Male; Mice; Mice, Inbred BALB C; Nitric Oxide Synthase Type II; Quercetin; Tumor Necrosis Factor-alpha

Isorhamnetin, a flavonoid compound extracted from plants' fruit or leaves, like sea buckthorn (Hippophae rhamnoides L.), has many biological functions, including anti-tumor, anti-oxidant and anti-inflammatory effect. The present study is in order to explore the hepatoprotective effect of isorhamnetin on concanavalin A (ConA)-induced acute fulminant hepatitis and the underlying mechanism. Mice were injected with ConA (25 mg/kg) to induce acute fulminant hepatitis, three doses of isorhamnetin (10/30/90 mg/kg) was intraperitoneally administrated about 1 h previously. The serum and liver tissues were harvested at 2, 8, and 24 h after ConA injection. The levels of serum liver enzymes and proinflammatory cytokines were significantly reduced in isorhamnetin administration groups. Besides, isorhamnetin improved pathological damage. Furthermore, isorhamnetin affected P38/PPAR-α pathway, and subsequently regulated the expression of apoptosis and autophagy related proteins. The present study investigated that isorhamnetin inhibits apoptosis and autophagy via P38/PPAR-α pathway in mice.

Topics: Animals; Apoptosis; Autophagy; Chemical and Drug Induced Liver Injury; Concanavalin A; Inflammation Mediators; Male; MAP Kinase Signaling System; Mice; Mice, Inbred BALB C; PPAR alpha; Quercetin

Eclipta prostrata L. is a traditional Chinese herbal medicine that has been used in the treatment of liver diseases. However, its biological mechanisms remain elusive. The current study aimed to investigate the hepatoprotective effect of wedelolactone, a major coumarin ingredient of Eclipta prostrata L., on immune-mediated liver injury. Using the well-established animal model of Concanavalin A (ConA)-induced hepatitis (CIH), we found that pretreatment of mice with wedelolactone markedly reduced both the serum levels of transaminases and the severity of liver damage. We further investigated the mechanisms of the protective effect of wedelolactone. In mice treated with wedelolactone prior to the induction of CIH, increases of serum concentrations of tumor necrosis factor (TNF)-[Formula: see text], interferon (IFN)-[Formula: see text], and interleukin (IL)-6 were dramatically attenuated. Additionally, expressions of the interferon-inducible chemokine (C-X-C motif) ligand 10 gene CXCL10 and intercellular adhesion molecule 1 gene ICAM1 were lower in livers of the treated mice. Moreover, wedelolactone-treated CIH mice exhibited reduced leukocyte infiltration and T-cell activation in liver. Furthermore, wedelolactone suppressed the activity of nuclear factor-kappa B (NF-[Formula: see text]B), a critical transcriptional factor of the above-mentioned inflammatory cytokines by limiting the phosphorylation of I kappa B alpha (I[Formula: see text]B[Formula: see text] and p65. In conclusion, these findings demonstrate the inhibitory potential of wedelolactone in immune-mediated liver injury in vivo, and show that this protection is associated with modulation of the NF-[Formula: see text]B signaling pathway.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Concanavalin A; Coumarins; Disease Models, Animal; Eclipta; Inflammation Mediators; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukin-6; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Phytotherapy; Signal Transduction; Tumor Necrosis Factor-alpha

The aim of the present study was to explore the effect of Bushen recipe and its disassembled prescriptions on liver injury and chronic hepatitis B. Liver injury was induced in normal and hepatitis B virus (HBV)‑transgenic mice through injection of Concanavalin A, followed by treatment with Bushen recipe and its disassembled prescriptions including the Bushen‑yang, the Bushen‑yin and the QingHua groups as well as the GanYanLing group (positive control). Subsequently, their liver function indexes were investigated by a microplate method and liver sections were blindly evaluated using an optical microscope by a pathologist. Subsequently, the activation state of Toll‑like receptor (TLR)3/9 signaling pathway in liver tissues was analyzed by western blotting. Additionally, the inflammatory factors produced following liver injury in peripheral blood were detected via ELISA. Following intervention with the Bushen recipe and its disassembled prescriptions, the liver function indexe alanine aminotransferase had declined, whereas cholinesterase increased. The pathological alterations of liver tissue in HBV transgenic mice were reversed by Bushen recipe and its disassembled prescriptions. In addition, the TLR3/9 signaling pathway in liver tissues of HBV transgenic mice was inhibited and inflammatory factors such as interleukin (IL)‑6, IL‑1, tumor necrosis factor‑α and interferon‑γ were reduced significantly. In conclusion, the present study demonstrated that Bushen recipe and its disassembled prescriptions repaired liver injury induced by Concanavalin A through inhibition of TLR3/9 signaling pathway.

Topics: Animals; Anti-Inflammatory Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Gene Expression Regulation; Genome; Hepatitis B virus; Interferon-gamma; Interleukin-1; Interleukin-6; Male; Mice; Mice, Transgenic; Signal Transduction; Toll-Like Receptor 3; Toll-Like Receptor 9; Tumor Necrosis Factor-alpha; Virus Integration

The gut-liver axis is of clinical importance as a potential therapeutic target in a wide range of liver diseases; however, the mechanisms underlying interactions between microbial products and immune responses in the liver remain unknown. In this study, we demonstrated that IL-10-producing macrophages contribute to immune tolerance in the inflamed liver under intestinal barrier disruption in a murine tandem model of dextran sulfate sodium (DSS) colitis and concanavalin A (Con A) hepatitis. Intestinal barrier disruption protected mice from subsequent liver injury, and the severity of colitis directly affected susceptibility to such injury. The protective effect of DSS-Con A was canceled in gut-sterilized mice, suggesting that gut microbiota play a substantial role in this process. Altered gut microbiota and their metabolites, along with a disrupted intestinal barrier, directly gave rise to immunological permissiveness in the inflamed liver. We identified 1-methylnicotinamide (1-MNA) as a candidate metabolite capable of suppressing liver injury with the potential to induce IL-10-producing macrophages. Consistently, expression of nicotinamide N-methyltransferase, which converts nicotinamide to 1-MNA, was upregulated in the liver of DSS-Con A mice, and this effect was abrogated by gut sterilization. Collectively, our results provide a mechanistic insight into the regulation of immunological balance in the liver via the gut-liver axis.

Topics: Animals; Chemical and Drug Induced Liver Injury; Colitis; Concanavalin A; Dextran Sulfate; Disease Models, Animal; Female; Gastrointestinal Microbiome; Hepatitis; Interleukin-10; Liver; Macrophages; Male; Mice; Mice, Inbred C57BL; Niacinamide; T-Lymphocytes

Autoimmune liver disease is a refractory disease clinically, and there is no particularly effective drug at present. Therefore, it is of important clinical value to develop new effective intervention drugs for the prevention and treatment of autoimmune liver disease. In order to investigate the potential protective effect of artesunate (Art) on concanavalin A (Con A)-induced autoimmune liver injury, different doses of Art (27, 54, 108 mg·kg⁻¹) were orally administered to mice for consecutive 7 days, respectively. Then the Con A was injected into mice via tail vein to induce liver injury models. 8 h after modeling, the mice were sacrificed. The serum and liver tissue were collected for detecting the level of alanine aminotransferase (ALT), and aspartate transaminase (AST), liver pathological histopathology, inflammatory cytokines and nuclear factor (NF-κB) key protein expression level. The results showed that 108 mg·kg⁻¹ Art remarkably reduced Con A-induced liver indexes and serum transaminase levels (ALT and AST) as compared with model group(

Topics: Alanine Transaminase; Animals; Artesunate; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Liver; Mice; NF-KappaB Inhibitor alpha; Protective Agents; Transcription Factor RelA

Fasiglifam (TAK-875), a G protein-coupled receptor 40 (GPR40) agonist, was a drug candidate for type 2 diabetes. However, its development was terminated in phase 3 trials due to liver safety concerns. Although TAK-875 was reported to inhibit hepatobiliary transporters and disturb bile acid disposition, pathogenic mechanisms of TAK-875-induced liver injury are not fully understood. In this study, we sought to identify the mechanisms with a hepatic genome-wide transcriptomic analysis in a murine model. We demonstrated that, among the three GPR40 agonists, TAK-875, AMG-837, and TUG-770, only TAK-875 induced acute liver injury in mice. Transcriptome profiles of TAK-875-exposed liver was compared with those of non-hepatotoxic analogues AMG-837 and TUG-770 as negative controls and those of classical hepatotoxicants concanavalin A and carbon tetrachloride as positive controls. The comparative hepatic transcriptome analyses revealed the enrichment of genes involved in inflammation, endoplasmic reticulum (ER) stress, apoptosis, and hepatic lipid accumulation, suggesting that these events play pathophysiologic roles in the development of TAK-875-induced liver injury. These results were validated by quantitative PCR with significant changes in chemokines, danger signals, ER stress mediators, proapoptotic factors, and hepatic steatosis markers only in TAK-875-exposed liver. Pretreatment of TAK-875-administered mice with an ER stress inhibitor 4-phenylbutyric acid (4-PBA) alleviated the liver injury. Consistent with the in vivo study, pretreatment of HepG2 cells with 4-PBA significantly improved the decrease of cell viability induced by TAK-875. In conclusion, by a comprehensive transcriptomic analysis, we found multiple possible processes that contribute to TAK-875-induced acute liver injury in mice.

Topics: Animals; Benzofurans; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Liver; Liver Failure, Acute; Mice; Mice, Inbred ICR; Molecular Structure; Sulfones; Transcriptome

Mice depleted of hepatic stellate cells (HSCs) are protected from concanavalin A (ConA)-induced liver injury that is mediated by the activation of interferon regulatory factor 1 (IRF1). The aim of this study was to determine the mechanisms of ConA-mediated signaling and synthesis/release of mediators by HSCs that damage hepatocytes. Primary cultures of wildtype (WT) and IRF1-knockout (KO) HSCs and hepatocytes were used, and ConA-induced liver damage in interferon (IFN)αβ receptor-deficient (IFNαβR-KO) mice was determined. Specific binding of ConA to HSCs induced rapid activation of JAK2 and STAT1. ConA-induced expression of IRF1, IFNβ, tumor necrosis factor α, and CXCL1 was abrogated by selective inhibition of JAK2 and STAT1. Despite activating JAK2/STAT1, ConA failed to stimulate expression of inflammatory cytokines in HSCs from IRF1-KO mice. ConA-conditioned WT-HSC medium caused activation of JNK and caspase 3, and apoptosis of hepatocytes from WT but not from IRF1-KO or IFNαβR-KO mice. Conversely, ConA-conditioned medium of IRF1-KO HSCs failed to cause apoptosis of WT or IRF1-KO hepatocytes. IFNαβR-KO mice were protected from ConA-induced liver damage, and ConA-induced hepatic expression of IRF1 and pro-inflammatory cytokines and chemokines, and infiltration of neutrophils were significantly lower in IFNαβR-KO than in WT mice. These results demonstrate distinct roles of IRF1 in hepatic inflammation (HSCs) and injury (hepatocytes) and can be an important target for intervention in acute liver injury.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Culture Media, Conditioned; Cytokines; Hepatic Stellate Cells; Interferon Regulatory Factor-1; Interferon-gamma; Male; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Receptor, Interferon alpha-beta; Signal Transduction; Superoxide Dismutase-1

Liver ischemia-reperfusion injury (IRI) and regeneration deficiency are two major challenges for surgery patients with chronic liver disease. As a survival factor for hepatocytes, interleukin 22 (IL-22) plays an important role in hepatoprotection and the promotion of regeneration after hepatectomy. In this study, we aim to investigate the roles of an interleukin 22 fusion protein (IL-22-FP) in mice with a predamaged liver after a two-third partial hepatectomy (PHx). Predamaged livers in mice were induced by concanavalin A (ConA)/carbon tetrachloride (CCl4) following PHx with or without IL-22-FP treatment. A hepatic IRI mouse model was also used to determine the hepatoprotective effects of IL-22-FP. In the ConA/CCl4 model, IL-22-FP treatment alleviated liver injury and accelerated hepatocyte proliferation. Administration of IL-22-FP activated the hepatic signal transducer and activator of transcription 3 (STAT3) and upregulated the expression of many mitogenic proteins. IL-22-FP treatment prior to IRI effectively reduced liver damage through decreased aminotransferase and improved liver histology. In conclusion, IL-22-FP promotes liver regeneration in mice with predamaged livers following PHx and alleviates IRI-induced liver injury. Our study suggests that IL-22-FP may represent a promising therapeutic drug against regeneration deficiency and liver IRI in patients who have undergone PHx.

Topics: Animals; Carbon Tetrachloride; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatectomy; Hepatocytes; Humans; Immunoglobulin Fc Fragments; Interleukin-22; Interleukins; Liver; Male; Mice; Mice, Inbred C57BL; Recombinant Fusion Proteins; Regeneration; STAT3 Transcription Factor

Though the biological effects of human placental extract have been widely studied, it has limited availability and its use poses ethical problems. Thus, domestic animal placental extracts are suggested as alternatives. In this study, the protective effect of sheep placental extract (SPE) on concanavalin A (Con A)-induced liver injury was investigated. BALB/c mice were randomly divided into six groups, including one normal group and five experimental groups, which received different oral doses of SPE (0, 5, 10 and 50 mg/kg) or a mixture of amino acids for 3 days before Con A injection. Compared with Con A-induced model group, the SPE administration significantly decreased serum aminotransaminase activity, alleviated pathological changes, recovered liver antioxidant capacity and prevented the increase of nitric oxide. Secretion of pro-inflammatory cytokines in serum decreased and mRNA expression of hepatic intercellular adhesion molecule-1, interferon-inducible chemokine 10 and inducible nitric oxide synthase were downregulated, while B-cell lymphoma-2 expression increased. The administration of amino acids mixture had no significant effect in most measurements compared with the model group, which indicated proteins and peptides, rather than individual amino acid, were largely responsible for the bioactivity of SPE. The results indicate SPE has potential therapeutic effects against immune-mediated hepatitis.

Topics: Animals; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Gene Expression; Inflammation Mediators; Mice; Nitric Oxide; Placental Extracts; Protective Agents; Reactive Oxygen Species; Sheep

CD95/Fas ligand (FasL) is a cell death-promoting member of the tumor necrosis factor family with important functions in the regulation of T-cell homeostasis and cytotoxicity. In T cells, FasL expression is tightly regulated on a transcriptional level involving a complex set of different transcription factors. The orphan nuclear receptor liver receptor homolog-1 (LRH-1/NR5a2) is involved in the regulation of development, lipid metabolism and proliferation and is predominantly expressed in epithelial tissues. However, its expression in T lymphocytes has never been reported so far. Based on in silico analysis, we identified potential LRH-1 binding sites within the FASLG promoter. Here, we report that LRH-1 is expressed in primary and secondary lymphatic tissues, as well as in CD4

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Fas Ligand Protein; Gene Expression Regulation; Liver; Mice; Mice, Mutant Strains; Receptors, Cytoplasmic and Nuclear; Response Elements; Transcription, Genetic

Concanavalin A (ConA) causes immune cell-mediated liver damage, but the contribution of resident nonparenchymal cells (NPCs) is also evident. Hepatic stellate cells (HSCs) induce hepatic inflammation and immunological reactions; we therefore investigated their role in ConA-induced liver injury. ConA was administered i.v. to control or HSC-depleted mice; hepatic histopathology and cytokines/chemokines were determined after 6 hours. In vitro, effects of ConA-conditioned HSC medium on hepatocytes were determined. ConA induced inflammation, sinusoidal congestion, and extensive midzonal hepatocyte death in control mice, which were strongly minimized in HSC-depleted mice. CD4 and natural killer T cells and neutrophils were markedly reduced in ConA-treated HSC-depleted mice compared with control mice. The increase in cytokines/chemokines of hepatic injury was much higher in ConA-treated control mice than in HSC-depleted mice. ConA-treated HSCs showed increased expression of interferon-β, tumor necrosis factor-α, and CXCL1, induced oxidative stress in hepatocytes, and caused hepatocyte apoptosis. ConA induced nuclear translocation of interferon-regulatory factor-1 (IRF1) in hepatocytes in vivo, and ConA/HSC induced a similar effect in cultured hepatocytes. IRF1-knockout mice were resistant to ConA-induced liver damage, and anti-interferon β antibody mitigated ConA/HSC-induced injury. In HSC-NPC co-culture, ConA-induced expression of inflammatory cytokines/chemokines was significantly augmented compared with NPCs alone. HSCs play an essential role in ConA-induced liver injury directly via the interferon-β/IRF1 axis, and by modulating properties of NPCs.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Cytokines; Hepatic Stellate Cells; Hepatocytes; Liver; Male; Mice

Excessive or persistent inflammation and hepatocyte death are the key triggers of liver diseases. The poly(ADP-ribose) polymerase (PARP) proteins induce cell death and inflammation. Chemical inhibition of PARP activity protects against liver injury during concanavalin A (ConA)-induced hepatitis. In this mice model, ConA activates immune cells, which promote inflammation and induce hepatocyte death, mediated by the activated invariant natural killer T (iNKT) lymphocyte population. We analyzed immune cell populations in the liver and several lymphoid organs, such as the spleen, thymus, and bone marrow in

Topics: Animals; Bone Marrow; Cell Death; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatitis; Hepatocytes; Inflammation; Mice; Natural Killer T-Cells; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Protective Factors; Spleen; Thymus Gland

Patients with inflammatory liver disease commonly develop debilitating symptoms, called sickness behaviors, which arise via changes in brain function. Monocytes that produce tumor necrosis factor interact with cerebral endothelial cells to activate microglial cells and promote sickness behavior. Platelets regulate inflammation, and aggregates of monocytes and platelets are increased in the circulation of patients with liver disease. We investigated the role of platelets in inducing inflammatory features of circulating monocytes and promoting sickness behaviors in mice with cholestatic liver injury.. We performed bile-duct ligations or sham surgeries on C57BL/6 or toll-like receptor 4 (TLR4)-knockout mice to induce liver inflammation. Liver inflammation was also induced in a separate group of mice by administration of concanavalin A. Circulating platelets, aggregates of monocytes and platelets, and activation of microglial cells were measured by flow cytometry. To deplete platelets, mice were given anti-thrombocyte serum or normal rabbit serum (control) 4 days after surgery. Interactions between monocytes and cerebral endothelial cells were analyzed by intravital microscopy. Sickness behaviors were quantified based on time spent by adult mice engaging in social behaviors toward a juvenile mouse, compared with time spent in nonsocial behavior or remaining immobile.. Aggregates of monocytes and platelets in circulation of mice increased significantly following bile-duct ligation. Platelet-monocyte interactions were required for activation of inflammatory monocytes and production of tumor necrosis factor. Platelet depletion greatly reduced adhesive interactions between inflammatory monocytes and adhesive interactions with cerebral endothelial cells and activation of the microglia, as well as development of sickness behavior. Furthermore, TLR4 signaling was important for aggregation of monocytes and platelets, and development of sickness behavior following bile-duct ligation. These findings were confirmed in mice with concanavalin A-induced liver injury.. In mice with liver inflammation, we found TLR4 and aggregates of monocytes and platelets to regulate microglial activation and development of sickness behavior. These findings might lead to new therapeutic strategies for liver disease-associated symptoms.

Topics: Animals; Behavior, Animal; Blood Platelets; Chemical and Drug Induced Liver Injury; Cholestasis; Concanavalin A; Disease Models, Animal; Endothelial Cells; Illness Behavior; Male; Mice, Inbred C57BL; Mice, Knockout; Microglia; Monocytes; Platelet Activation; Social Behavior; Toll-Like Receptor 4

Ungoverned activation of innate and adaptive immunity results in acute inflammatory disease, such as bacteria-induced endotoxemia and fulminant hepatitis by virus infection. Thus, therapeutic control of inflammation is crucial for clinical management of many human diseases. In murine models of LPS- and Con A-induced liver injury, we found that naringenin, a natural predominant flavanone, is capable of protecting against lethality induced by LPS and preventing inflammation-induced organ injury. The protective effect of naringenin is mediated by reducing the levels of several inflammatory cytokines. Unexpectedly, naringenin inhibits TNF-α and IL-6 secretion in macrophages and T cells without interfering with the TLR signaling cascade, cytokine mRNA stability, or protein translation. These results indicate the existence of a posttranslational control mechanism. Further studies show that naringenin enhances intracellular cytokine degradation through lysosome- and TFEB-dependent mechanisms. This study provides evidence that naringenin has the capacity to dampen cytokine production by regulating lysosome function. Thus, naringenin may represent a potential therapeutic agent for controlling inflammation-related diseases.

Topics: Animals; Anti-Inflammatory Agents; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Endotoxemia; Female; Flavanones; Humans; Inflammation Mediators; Lipopolysaccharides; Lysosomes; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL

Autoimmune hepatitis (AIH) is a severe necroinflammatory liver disease associated with significant mortality. Although loss of hepatocytes is generally recognised as a key trigger of liver inflammation and liver failure, the regulation of hepatic cell death causing AIH remains poorly understood. The aim of this study was to identify molecular mechanisms that drive hepatocyte cell death in the pathogenesis of acute liver injury.. Acute liver injury was modelled in mice by intravenous administration of concanavalin A (ConA). Liver injury was demonstrated by serum transaminases and histological assessment of liver sections. PGAM5-deficient mice (PGAM5-/-) were used to determine its role in experimental hepatitis. Mdivi-1 was used as an inhibitor of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. Mitochondrial fission and the expression of PGAM5 were compared between liver biopsies derived from patients with AIH and control patients.. PGAM5 was highly expressed in hepatocytes of patients with AIH and in mice with ConA-induced experimental hepatitis. Deficiency of PGAM5 protected mice from ConA-induced hepatocellular death and liver injury. PGAM5 regulated ConA-induced mitochondrial fission in hepatocytes. Administration of the Drp1-inhibitor Mdivi-1 blocked mitochondrial fission, diminished hepatocyte cell death and attenuated liver tissue damage induced by ConA.. Our data demonstrate for the first time that PGAM5 plays an indispensable role in the pathogenesis of ConA-induced liver injury. Downstream of PGAM5, Drp1-mediated mitochondrial fission is an obligatory step that drives the execution of hepatic necrosis and tissue damage. Our data highlight the PGAM5-Drp1 axis as a potential therapeutic target for acute immune-mediated liver injury.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Case-Control Studies; Cell Death; Chemical and Drug Induced Liver Injury; Concanavalin A; Dynamins; Gene Expression; Hepatitis, Autoimmune; Hepatocytes; Humans; Liver; Mice; Mice, Knockout; Mitochondrial Dynamics; Mitochondrial Proteins; Necrosis; Phosphoprotein Phosphatases; Quinazolinones

Liver largely relies on its innate immunity to initiate quick and effective defense against potentially toxic agents, and innate immune cells are major players in this process. However, excessive inflammation due to out-of-control immune response may eventually cause liver injury. Thus, it is important to fully understand the regulatory mechanisms associated with liver inflammation. Here we showed that anti-CD24 neutralizing antibody exacerbated hepatic inflammation in a Con A-induced acute liver injury murine model. Our results supported that hepatic macrophages were required for anti-CD24 neutralizing antibody-aggravated liver inflammation, as depletion of macrophages significantly alleviated Con A-induced inflammation. M1 macrophages, but not M2 macrophages, were specifically induced by Con A, and more greatly by Con A in combination with anti-CD24 neutralizing antibody. The combined treatment further promoted M1 hepatic macrophages to express TNF-α, which increased hepatocytes apoptosis. Taken together, these data suggest that anti-CD24 neutralizing antibody plays an important role in aggravating inflammation in the process of Con A-induced acute liver injury in mice. The possible mechanism might involve the enhanced secretion of TNF-α by hepatic M1 macrophages. This study also implicates a role for CD24 in negative regulation of Con A-induced liver inflammation.

Topics: Animals; Antibodies, Monoclonal; Antibodies, Neutralizing; CD24 Antigen; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Gene Expression Profiling; Kupffer Cells; Leukocytes; Macrophages; Male; Mice; Tumor Necrosis Factor-alpha

Salecan, a water-soluble extracellular β-glucan produced by Agrobacterium sp. ZX09, has been reported to exhibit a wide range of biological effects. The aims of the present study were to investigate the protective effect of salecan against Concanavalin A (ConA)-induced hepatitis, a well-established animal model of immune-mediated liver injury, and to search for possible mechanisms. C57BL/6 mice were pretreated with salecan followed by ConA injection. Salecan treatment significantly reduced ConA-induced acute liver injury, and suppressed the expression and secretion of inflammatory cytokines including interferon (IFN)-γ, interleukin (IL)-6 and IL-1β in ConA-induced liver injury model. The high expression levels of chemokines and adhesion molecules such as MIP-1α, MIP-1β, ICAM-1, MCP-1 and RANTES in the liver induced by ConA were also down-regulated after salecan treatment. Salecan inhibited the infiltration and activation of inflammatory cells, especially T cells, in the liver induced by ConA. Moreover, salecan reversed the metabolic profiles of ConA-treated mice towards the control group by partly recovering the metabolic perturbations induced by ConA. Our results suggest the preventive and therapeutic potential of salecan in immune-mediated hepatitis.

Topics: Animals; beta-Glucans; Chemical and Drug Induced Liver Injury; Concanavalin A; Immunity, Cellular; Magnetic Resonance Spectroscopy; Male; Metabolome; Mice; Mice, Inbred C57BL; T-Lymphocytes

The pregnane X receptor (PXR) is well-known as a key regulator of drug/xenobiotic clearance. Upon activation by ligand, PXR transcriptionally upregulates the expression of drug-metabolizing enzymes and drug transporters. Recent studies have revealed that PXR also plays a role in regulating immune/inflammatory responses. Specific PXR activators, including synthetic ligands and phytochemicals, have been shown to ameliorate chemically induced colitis in mice. In this study, we investigated an anti-inflammatory effect of pregnenolone 16α-carbonitrile (PCN), a prototypical activator for rodent PXR, in concanavalin A (Con A)-induced liver injury, a model of immune-mediated liver injury, using wild-type and Pxr

Topics: Alanine Transaminase; Animals; Biomarkers; CD2 Antigens; Chemical and Drug Induced Liver Injury; Chemokine CXCL2; Concanavalin A; Cytoprotection; Disease Models, Animal; Gene Expression Regulation; Immunosuppressive Agents; Liver; Male; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Pregnane X Receptor; Pregnenolone Carbonitrile; Receptors, Steroid; Signal Transduction

Toll-like receptor-5 (TLR5) signaling regulates the immune privileged status of the liver and is involved in hepatic immune disorders. However, the role of TLR5 has not yet been investigated in experimental models of concanavalin A (Con A)-mediated liver injury. Here, we show that TLR5 is highly up-regulated in the hepatic mononuclear cells of mice during Con A-induced hepatitis. Increased mortality and liver histopathology of TLR5-deficient mice correlated with excessive production of proinflammatory cytokines, suggesting that TLR5 knockout mice were more susceptible to Con A-induced hepatitis. We also report that administration of CBLB502, an exogenous TLR5 agonist, substantially alleviated Con A-mediated hepatitis in wild-type mice as shown by increased survival rates, reduced aminotransferase and proinflammatory cytokine production, impaired lymphocyte infiltration, and ameliorated hepatocyte necrosis and/or apoptosis. Mechanistic studies revealed that CBLB502 acts as a negative regulator in limiting T-cell/natural killer T-cell activity and cytokine production in the Con A-hepatitis model. Bone marrow transplantation experiments showed that TLR5 in bone marrow-derived cells contributed to the hepatoprotective efficacy of CBLB502 against Con A-induced liver injury. Moreover, interleukin-6 elevation induced by CBLB502 is an important protective factor against Con A-induced liver injury. In addition, we demonstrate that CBLB502 suppresses α-galactosylceramide-induced natural killer T cell-dependent inflammatory liver injury.. The TLR5 signaling pathway plays an important role in T cell-mediated hepatic injury and may be exploited for therapeutic treatment of inflammatory liver diseases. (Hepatology 2017;65:2059-2073).

Topics: Animals; Biopsy, Needle; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Flow Cytometry; Hepatocytes; Immunohistochemistry; Inflammation Mediators; Kaplan-Meier Estimate; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Peptides; Random Allocation; Reference Values; Signal Transduction; Survival Rate; Toll-Like Receptor 5

Nymphaea candida was used to treat hepatitis in Ugyhur medicine, and nicotiflorin (kaempferol 3-O-β-rutinoside) is the main characteristic component in this plant [...].

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Flavonoids; Galactosamine; Liver Function Tests; Mice; Molecular Structure; Nymphaea; Oxidation-Reduction; Oxidative Stress; Phenols; Plant Extracts; Protective Agents

To investigate the inhibitory effect of\ Yiguanjian decoction (YD) on DNA damage in Concanavalin\ A (Con A)-induced liver injury mice model\ and to explain the possible mechanism.. METHODS: Totally 120 male BALB/c mice were randomly\ divided into 6 groups, 20 mice each: normal\ group, model group, Bifendate group, YD low dose\ group, YD middle dose group and YD high dose\ group. Except normal group, liver injury model induced\ by Con A was established. While modeling,\ each mouse in YD group was given YD (0.4 mL/20 g\ per day) by intragastric administration (0.13 g YD\ for YD low dose group; 0.26 g for YD middle dose\ group; 0.52 g for YD high dose group). Bifendate\ group was given Bifendate (0.2 g·kg-1·d-1) by gavage.\ Normal group and model group were fed\ with same volume of physiological saline daily. After\ 8 weeks, the serum alanine transaminase (ALT)\ and aspartate transaminase (AST) were tested. The\ hematoxylin-eosin staining was used to evaluate\ the grade of liver inflammation and liver fibrosis\ stage. Hepatocellular DNA damage was detected\ by single cell gel electrophoresis technology. The\ protein expression of tumor necrosis factor-α\ (TNF-α), Bax and MutT Homolog 1 (MTH1) was detected\ by western blotting and enzyme linked immunosorbent\ assay. Bax mRNA and MTH1 mRNA\ were detected by Real-time Polymerase Chain Reaction\ (PCR).. YD can improve the degree of liver inflammation\ and fibrosis in the liver of chronic hepatitis\ mice, the dose effect relationship is remarkable\ (P < 0.05). YD can reduce liver cell DNA damage.\ The difference between YD middle dose group and\ model group was statistically significant (P < 0.05).\ YD middle dose group had decreased the protein\ expression of TNF-α in the mice liver of immunological\ liver injury (P < 0.05). YD can increase the protein\ expression of Bax (P < 0.05). Compared with\ normal group, the protein expression of MTH1 was\ decreased (P < 0.05), but there was no statistical significance\ between YD group and model group (P >\ 0.05). YD can increase the mRNA expression of Bax\ and MTH1 (both P < 0.05).. YD can effectively inhibit the DNA\ damage in immunological liver injury mice, the\ mechanism may be that it can decrease the TNF-α\ and increase the Bax and MTH1 expression.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; DNA Damage; Drugs, Chinese Herbal; Humans; Liver; Male; Mice; Mice, Inbred BALB C; Protective Agents

Hepatic stellate cells (HSCs) constitute the liver sinusoid with Kupffer cells and liver sinusoidal endothelial cells. While the sinusoid functions as the gateway to liver inflammation, whether HSCs contribute to liver inflammation and, if so, how they exert such functions remain elusive. Here, we found that mouse as well as human HSCs expressed DP1 receptor for prostaglandin D2 selectively in the liver. Pharmacological stimulation of DP1 by BW245C, a DP1-selective agonist, suppressed the activation of cultured HSCs by tumor necrosis factor-α at least in part through down-regulation of nuclear factor kappa-light-chain-enhancer of activated B cells signaling and inhibition of c-Jun N-terminal kinase phosphorylation. DP1 deficiency or BW245C administration in mice significantly enhanced or suppressed concanavalin A (ConA)-induced hepatitis, respectively. ConA injection induced tumor necrosis factor-α and interferon-γ expression in the sinusoid, which was suppressed by administration of BW245C. Coculture of spleen cells and liver nonparenchymal cells showed that ConA first activated spleen cells and that this activation led to activation of nonparenchymal cells to secondarily produce tumor necrosis factor-α and interferon-γ. Microarray analysis revealed ConA-induced expression of endothelin-1, tissue factor, and chemokines in the liver and inducible nitric oxide synthase in hepatocytes, resulting in flow stagnation, leukocyte adherence and migration to the parenchyma, and hepatocyte death. DP1 stimulation inhibits all these events in the liver. Therefore, HSCs mediate amplification of ConA-induced liver inflammation in the sinusoid, causing direct and indirect hepatocyte injury, and DP1 stimulation inhibits this HSC activation.. HSCs integrate cytokine-mediated inflammatory responses in the sinusoids and relay them to the liver parenchyma, and these HSC actions are inhibited by DP1 stimulation.

Topics: Animals; Biopsy, Needle; Case-Control Studies; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Disease Models, Animal; Female; Hepatic Stellate Cells; Hepatitis C; Humans; Immunohistochemistry; Interferon-gamma; Kupffer Cells; Male; Mice; Mice, Inbred C57BL; Phosphorylation; Random Allocation; Real-Time Polymerase Chain Reaction; Reference Values; Sensitivity and Specificity; Signal Transduction; Tumor Necrosis Factor-alpha

We have recently demonstrated that concanavalin A (Con A)-induced hepatitis is associated with the release of endogenous 1-methylnicotinamide (MNA). Here we study the mechanism by which exogenous MNA alleviates Con A-induced liver inflammation and injury in vivo. The involvement of prostacyclin (PGI2) in hepatoprotective action of MNA (30-100 mg kg(-1); i.v.) was studied by the use of IP receptor antagonist RO3244794 (10 mg kg(-1); p.o.) given prior to Con A (5-20 mg kg(-1); i.v.). Liver damage was assessed by measurements of: liver specific transaminases in plasma (alanine aminotransferase; aspartate aminotransferase); cytokines release (IL-4, IFN-γ and TNF-α); liver histopathology; and 24h survival rates. Additionally, the effect of a stable analog of prostacyclin (carbaprostacyclin) on IL-4, IFN-γ and TNF-α production by isolated spleen lymphocytes in response to Con A was analyzed. MNA diminished Con A-induced rise in liver specific transaminases, alleviated histopathological injury and improved 24h survival rates, the latter effect in a degree comparable with the pretreatment of animals with dexamethasone (0.5 mg kg(-1); i.p.). MNA inhibited also a rise in IL-4 and TNF-α concentration in plasma measured 2 h after Con A administration, while IFN-γ was less affected. The effects of MNA were reversed by pretreatment with IP antagonist RO3244794. In isolated spleen lymphocytes, carbaprostacyclin profoundly decreased production of IL-4, the effect on TNF-α was modest with no effect on IFN-γ production. In conclusion, MNA attenuated Con A-induced hepatitis by a prostacyclin-dependent mechanism involving the inhibition of lymphocytes-derived IL-4 and the inhibition of Kuppfer-cells derived TNF-α.

Topics: Animals; Benzofurans; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Dexamethasone; Epoprostenol; Interleukin-4; Liver; Mice; Mice, Inbred BALB C; Niacinamide; Propionates; Receptors, Epoprostenol; Tumor Necrosis Factor-alpha

Angelica sinensis polysaccharide (ASP), extracted from the roots of A. sinensis (Oliv.) Diels, is a β-D-pyranoid polysaccharide with an average molecular weight of 72,900 Da. In this study, we investigated the protective effects of ASP against concanavalin A-induced liver failure and the underlying mechanisms. Concentrations of ASP ranging from 5 to 125 μg/mL could inhibit concanavalin A (ConA)-induced lymphoproliferative response. The potential hepatoprotective activity of ASP was demonstrated by the significant decrease in serum transaminase (ALT and AST) levels and the attenuation of liver inflammation damage exhibited by H&E stain of the liver. Furthermore, ASP pretreatment significantly decreased proinflammatory cytokines (TNF-α, IFN-γ, IL-2 and IL-6) and alleviated oxidative stress by reducing MDA and ROS levels and by enhancing SOD activity after ConA administration in mice. Results of Western blot analysis indicated that ASP attenuated Caspase-3-dependent apoptosis by Caspase-8 and JNK-mediated pathway and inhibited the activation of IL-6/STAT3 and NF-κB signaling pathways in ConA-induced liver damage in mice. In conclusion, ASP pretreatment could attenuate concanavalin A-induced liver injury through its anti-inflammatory and anti-oxidant actions in mice.

Topics: Angelica sinensis; Animals; Antigens, Plant; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Humans; Liver; Mice; NF-kappa B; Plant Roots; Polysaccharides; Signal Transduction; STAT3 Transcription Factor

Extract of Rabdosia amethystoides (Benth) Hara (ERA), a traditional Chinese medicine has antibacterial, antiviral, anti-tumor, anti-hepatitis and anti-inflammatory properties. However, the hepatoprotective effects and molecular mechanisms of ERA on acute liver injury have not been fully elucidated. This study aims to investigate the anti-inflammatory effect and liver protection of ERA against the acute liver injury induced by Concanavalin A (Con A) and its underlying molecular mechanisms in mice. Mice received ERA (50, 100, 150 mg/kg body weight) by gavage before Con A intravenous administration. We found that ERA pretreatment was able to significantly reduce the elevated serum alanine and aspartate aminotransferase levels and liver necrosis in Con A-induced hepatitis. In addition, ERA treatment significantly decreased the myeloperoxidase, malondialdehyde levels and augmented superoxide dismutase level in the liver tissue, and also suppressed the secretion of proinflammatory cytokines in the serum, compared with Con A group by enzyme linked immunosorbent assay. Furthermore, we observed that ERA pretreatment can significantly decrease the expression level of Toll-like receptor (TLR) 4 mRNA or protein in liver tissues. Further results showed that ERA pretreatment was capable of attenuating the activation of the NF-κB pathway by inhibiting IκBα kinase and p65 phosphorylation in Con A-induced liver injury. Our results demonstrate that ERA pretreatment has hepatoprotective property against Con A-induced liver injury through inhibition of inflammatory mediators in mice. The beneficial effect of ERA may be mediated by the downregulation of TLR4 expression and the inhibition of NF-κB activation.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Down-Regulation; Gene Expression; Isodon; Liver; Male; Mice, Inbred ICR; NF-kappa B; Phytotherapy; Plant Extracts; RNA, Messenger; Signal Transduction; Toll-Like Receptor 4

To investigate the therapeutic effects and mechanisms of interleukin (IL)-22 in liver regeneration in mice with concanavalin A (ConA)-induced liver injury following 70% hepatectomy.. Mice were injected intravenously with ConA at 10 μg/g body weight 4 d before 70% hepatectomy to create a hepatitis model, and recombinant IL-22 was injected at 0.125 μg/g body weight 30 min prior to 70% hepatectomy to create a therapy model. Control animals received an intravenous injection of an identical volume of normal saline.. IL-22 treatment prior to 70% hepatectomy performed under general anesthesia resulted in reductions in the biochemical and histological evidence of liver injury, earlier proliferating cell nuclear antigen expression and accelerated recovery of liver mass. IL-22 pretreatment also significantly induced signal transducer and activator of transcription factor 3 (STAT3) activation and increased the expression of a variety of mitogenic proteins, such as Cyclin D1. Furthermore, alpha fetal protein mRNA expression was significantly elevated after IL-22 treatment.. In this study, we demonstrated that IL-22 is a survival factor for hepatocytes and prevents and repairs liver injury by enhancing pro-growth pathways via STAT3 activation. Treatment with IL-22 protein may represent a novel therapeutic strategy for preventing liver injury in patients with liver disease who have undergone hepatectomy.

Topics: alpha-Fetoproteins; Animals; Cell Cycle Proteins; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Female; Hepatectomy; Injections, Intravenous; Interleukin-22; Interleukins; Liver; Liver Regeneration; Mice, Inbred C57BL; Signal Transduction; STAT3 Transcription Factor; Time Factors

Epigallocatechin-3-gallate (EGCG) is the most effective compound in green tea, and possesses a wide range of beneficial effects, including anti-inflammatory, antioxidant, antiobesity, and anticancer effects. In this study, we investigated the protective effects of EGCG in concanavalin A (ConA)-induced hepatitis in mice and explored the possible mechanisms involved in these effects.. Balb/C mice were injected with ConA (25 mg/kg) to induce acute autoimmune hepatitis, and EGCG (10 or 30 mg/kg) was administered orally twice daily for 10 days before ConA injection. Serum liver enzymes, proinflammatory cytokines, and other marker proteins were determined 2, 8, and 24 hours after the ConA administration.. BNIP3 mediated cell apoptosis and autophagy in ConA-induced hepatitis. EGCG decreased the immunoreaction and pathological damage by reducing inflammatory factors, such as TNF-α, IL-6, IFN-γ, and IL-1β. EGCG also exhibited an antiapoptotic and antiautophagic effect by inhibiting BNIP3 via the IL-6/JAKs/STAT3 pathway.. EGCG attenuated liver injury in ConA-induced hepatitis by downregulating IL-6/JAKs/STAT3/BNIP3-mediated apoptosis and autophagy.

Topics: Animals; Apoptosis; Autophagy; Catechin; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Janus Kinase 1; Janus Kinase 2; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Mitochondrial Proteins; Signal Transduction; STAT3 Transcription Factor

Protectin D1 (PD1) is a bioactive product generated from docosahexaenoic acid, which may exert anti-inflammatory effects in various inflammatory diseases. However, the underlying molecular mechanism of its anti‑inflammatory activity on concanavalin A (Con A)-induced hepatitis remains unknown. The aim of the present study was to investigate the protective effects of PD1 against Con A‑induced liver injury and the underlying mechanisms via intravenous injection of PD1 prior to Con A administration. C57BL/6 mice were randomly divided into four experimental groups as follows: Control group, Con A group (30 mg/kg), 20 µg/kg PD1 + Con A (30 mg/kg) group and 10 µg/kg PD1 + Con A (30 mg/kg) group. PD1 pretreatment was demonstrated to significantly inhibit elevated plasma aminotransferase levels, high mobility group box 1 and liver necrosis, which were observed in Con A‑induced hepatitis. Furthermore, compared with the Con A group, PD1 pretreatment prevented the production of pro‑inflammatory cytokines, including tumor necrosis factor‑α, interferon‑γ and interleukin‑2, ‑1β and ‑6. In addition, pretreatment with PD1 markedly downregulated cluster of differentiation (CD)4+, CD8+ and natural killer T (NKT) cell infiltration in the liver. PD1 pretreatment was observed to suppress the messenger RNA and protein expression levels of NLR family, pyrin domain containing 3 and Toll‑like receptor (TLR) 4 in liver tissue samples. Further data indicated that PD1 pretreatment inhibited the activation of the nuclear factor κ‑light‑chain‑enhancer of activated B cells (NF‑κB) signaling pathway and chemokine (C‑X3‑C motif) ligand 1 (CX3CL1)/chemokine (C-X3-C motif) receptor 1 (CX3CR1) axis by preventing phosphorylation of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor, α and NF‑κB in Con A‑induced liver injury. Therefore, these results suggest that PD1 administration protects mice against Con A‑induced liver injury via inhibition of various inflammatory cytokines and, in part, by suppressing CD4+, CD8+ and NKT cell infiltration in the liver and the NF‑κB‑activated CX3CL1/CX3CR1 signaling pathway. The beneficial effect of PD1 may be associated with the inhibition of TLR4 expression and the downregulation of NF‑κB activation. In conclusion, PD1 appears to be a potential natural bioproduct, and provide a promising strategy, for the prevention of hepatic injury in patients with chronic or acute liver disease.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokine CX3CL1; Concanavalin A; CX3C Chemokine Receptor 1; Cytokines; Docosahexaenoic Acids; Inflammasomes; Liver; Male; Mice; Mice, Inbred C57BL; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Receptors, Chemokine; Signal Transduction; T-Lymphocytes; Toll-Like Receptor 4; Transaminases

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Hepatic Stellate Cells; Hepatitis C; Humans; Male

Alpha-lipoic acid (α-LA), which exits in almost all types of prokaryotic and eukaryotic cells, is a key regulator of energy metabolism in mitochondria. This study was designed to explore the protective effect of α-LA against concanavalin A (Con A)-induced hepatitis in mice and explore the potential mechanism.. Acute autoimmune hepatitis was induced by intravenous (IV) injection of Con A (15mg/kg) in C57BL/6 mice. α-LA (100mg/kg) was administered four days before Con A injection. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and histopathological change of the liver tissue were measured. Serum cytokine TNF-α, IL-6, IFN-γ and IL-10 were detected by ELISA. The mRNA levels of these inflammatory cytokines in the liver were detected by RT-PCR. Malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD) and reduced/oxidized glutathione (GSH/GSSG) in liver were determined using commercial kits. Phosphorylated NF-κB p65, IκBα and phosphorylated MAPK were measured by Western blot.. Con A injection induced severe immune responses and extensive hepatocellular apoptosis within 12h. Pretreatment of α-LA markedly reduced the serum ALT and AST activity and the increase of plasma TNF-α, IL-6, IFN-γ and IL-10. In addition, α-LA pretreatment decreased the tissue MPO activity and lipid peroxidation, but increased SOD and GSH levels. α-LA inhibited the phosphorylation of NF-κB p65, IκBα and JNK.. Pretreatment of α-LA markedly attenuated Con A-induced hepatitis by modulating cytokine secretion and reducing reactive oxygen species generation.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Inflammation Mediators; Lipid Peroxidation; Liver; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Oxidative Stress; Peroxidase; Reactive Oxygen Species; Signal Transduction; Thioctic Acid

This study aimed to explore the effects of fucoidan from Fucus vesiculosus on concanavalin A (ConA)-induced acute liver injury in mice. Pretreatment with fucoidan protected liver function indicated by ALT, AST and histopathological changes by suppressing inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). In addition, intrinsic and extrinsic apoptosis mediated by Bax, Bid, Bcl-2, Bcl-xL and Caspase 3, 8, and 9 were inhibited by fucoidan and the action was associated with the TRADD/TRAF2 and JAK2/STAT1 signal pathways. Our results demonstrated that fucoidan from Fucus vesiculosus alleviated ConA-induced acute liver injury via the inhibition of intrinsic and extrinsic apoptosis mediated by the TRADD/TRAF2 and JAK2/STAT1 pathways which were activated by TNF-α and IFN-γ. These findings could provide a potential powerful therapy for T cell-related hepatitis.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Fucus; Male; Mice; Mice, Inbred BALB C; Plant Extracts; Polysaccharides; Signal Transduction

Invariant NKT (iNKT) cells represent a subset of innate-like T lymphocytes that function as orchestrators of hepatic inflammation underpinning liver damage. In this study, we demonstrate that TPL2, an MAP3 kinase that has mostly been appreciated for its physiological role in macrophage responses, is a signaling factor in CD3(+)NK1.1(+) iNKT cells and mediator of hepatic inflammation. Genetic ablation of TPL2 in the mouse ameliorates liver injury induced by Con A and impinges on hallmarks of NKT cell activation in the liver without affecting NKT cell development in the thymus. The pivotal role of TPL2 in iNKT cell functions is further endorsed by studies using the iNKT-specific ligand α-galactosylceramide, which causes mild hepatitis in the mouse in a TPL2-dependent manner, including production of the effector cytokines IL-4 and IFN-γ, accumulation of neutrophils and licensing and activation of other immune cell types in the liver. A TPL2 kinase inhibitor mirrors the effects of genetic ablation of TPL2 in vivo and uncovers ERK and Akt as the TPL2-regulated signaling pathways responsible for IL-4 and IFN-γ expression through the activation of the transcription factors JunB and NFAT. Collectively, these findings expand our understanding of the mechanisms of iNKT cell activation and suggest that modulation of TPL2 has the potential to minimize the severity of immune-driven liver diseases.

Topics: Adoptive Transfer; Animals; CD3 Complex; Cell Line; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Extracellular Signal-Regulated MAP Kinases; Female; Galactosylceramides; Hepatitis; Immunologic Factors; Interferon-gamma; Interleukin-4; Liver; Lymphocyte Activation; Macrophages; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; Mitogens; Natural Killer T-Cells; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Signal Transduction; Thymus Gland; Transcription Factors

CD4(+) T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4(+) T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4(-)CD8(-)NK1.1(-) double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4(+) rather than CD8(+) T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4(+) T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases.

Topics: Animals; CD4-Positive T-Lymphocytes; Cell Differentiation; Cell Movement; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Chemokine CXCL9; Concanavalin A; Cytokines; Granzymes; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; OX40 Ligand; Perforin; Receptors, CXCR3; Recombinant Fusion Proteins; RNA, Messenger; T-Lymphocytes; T-Lymphocytes, Regulatory

Shikonin possesses anti-inflammatory effects. However, its function in concanavalin A-induced acute liver injury remains uncertain. The aim of the present study was to investigate the functions of shikonin and its mechanism of protection on ConA-induced acute liver injury.. Balb/C mice were exposed to ConA (20 mg/kg) via tail vein injection to establish acute liver injury; shikonin (7.5 mg/kg and 12.5 mg/kg) was intraperitoneally administered 2 h before the ConA injection. The serum liver enzyme levels and the inflammatory cytokine levels were determined at 3, 6, and 24 h after ConA injection.. After the injection of ConA, inflammatory cytokines IL-1β, TNF-α, and IFN-γ were significantly increased. Shikonin significantly ameliorated liver injury and histopathological changes and suppressed the release of inflammatory cytokines. The expressions of Bcl-2 and Bax were markedly affected by shikonin pretreatment. LC3, Beclin-1, and p-JNK expression levels were decreased in the shikonin-pretreated groups compared with the ConA-treated groups. Shikonin attenuated ConA-induced liver injury by reducing apoptosis and autophagy through the inhibition of the JNK pathway.. Our results indicated that shikonin pretreatment attenuates ConA-induced acute liver injury by inhibiting apoptosis and autophagy through the suppression of the JNK pathway.

Topics: Animals; Blotting, Western; Chemical and Drug Induced Liver Injury; Concanavalin A; Immunohistochemistry; Interferon-gamma; Interleukin-1beta; Liver; Male; MAP Kinase Signaling System; Mice, Inbred BALB C; Naphthoquinones; Random Allocation; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Tumor Necrosis Factor-alpha

The IL-33/ST2 axis plays a protective role in T-cell-mediated hepatitis, but little is known about the functional impact of endogenous IL-33 on liver immunopathology. We used IL-33-deficient mice to investigate the functional effect of endogenous IL-33 in concanavalin A (Con A)-hepatitis. IL-33(-/-) mice displayed more severe Con A liver injury than wild-type (WT) mice, consistent with a hepatoprotective effect of IL-33. The more severe hepatic injury in IL-33(-/-) mice was associated with significantly higher levels of TNF-α and IL-1β and a larger number of NK cells infiltrating the liver. The expression of Th2 cytokines (IL-4, IL-10) and IL-17 was not significantly varied between WT and IL-33(-/-) mice following Con A-hepatitis. The percentage of CD25(+) NK cells was significantly higher in the livers of IL-33(-/-) mice than in WT mice in association with upregulated expression of CXCR3 in the liver. Regulatory T cells (Treg cells) strongly infiltrated the liver in both WT and IL-33(-/-) mice, but Con A treatment increased their membrane expression of ST2 and CD25 only in WT mice. In vitro, IL-33 had a significant survival effect, increasing the total number of splenocytes, including B cells, CD4(+) and CD8(+) T cells, and the frequency of ST2(+) Treg cells. In conclusion, IL-33 acts as a potent immune modulator protecting the liver through activation of ST2(+) Treg cells and control of NK cells.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Chemotaxis, Leukocyte; Concanavalin A; Cytokines; Disease Models, Animal; Genetic Predisposition to Disease; Hepatitis; Inflammation Mediators; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Killer Cells, Natural; Liver; Lymphocyte Activation; Mice, Inbred C57BL; Mice, Knockout; Phenotype; Signal Transduction; T-Lymphocytes, Regulatory

Interleukin (IL)-38 is a poorly characterized cytokine of the IL-1 family with anti-inflammatory activity. The role of IL-38 in liver injury remains unknown. We have investigated the potential effect of hydrodynamic-based gene delivery to express human IL-38 in mice with concanavalin A (Con A)-induced liver injury. Transfer of plasmid DNA encoding IL-38 significantly reduced hepatic toxicity and serum levels of aspartate aminotransferase and alanine aminotransferase compared with administration of a control plasmid. Moreover, IL-38 expression dramatically reduced serum levels of several pro-inflammatory cytokines, such as tumor necrosis factor-α, interferon-γ, IL-6, IL-17, and IL-22, but not levels of the anti-inflammatory cytokine IL-10. These results suggest that in vivo expression of human IL-38 in mice has hepatoprotective effects against Con A-induced liver injury by inhibition of inflammatory cytokine production.

Topics: Administration, Intravenous; Alanine Transaminase; Animals; Aspartate Aminotransferases; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Gene Transfer Techniques; Humans; Inflammation Mediators; Interleukins; Male; Mice; Mice, Inbred BALB C; Transgenes

This study aimed to evaluate the potential protective effects of pirfenidone (PFD) against concanavalin A (Con A)-induced hepatitis in mice.. Autoimmune model of hepatitis was established using single intravenous injection of Con A. Mice were randomly assigned into four groups as follows: control group; Con A group; and two groups, receiving PFD in two dose levels (200, 300 mg/kg) for 5 days before Con A administration. Extent of hepatitis was studied using biochemical, histopathological and immunohistochemical estimations.. Hepatitis was clearly evident through extensive hepatocellular lesions and elevated levels of serum transaminases, alkaline phosphatase and lactate dehydrogenase. Con A induced an imbalance between oxidant and antioxidant status in the hepatic tissue. Furthermore, Con A significantly elevated hepatic nuclear factor kappa B (NF-κB) expression and inflammatory cytokines levels (tumour necrosis factor-alpha, interleukin-6 and nitric oxide). PFD pretreatment potently ameliorated all these pathological changes.. Pirfenidone hepatoprotective activity may be mediated through its antioxidant ability that suppresses NF-κB activation signalling pathways suggesting that PFD may be a new candidate for treatment of acute hepatitis.

Topics: Animals; Antioxidants; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytoprotection; Disease Models, Animal; Hepatitis, Autoimmune; Liver; Male; Mice; NF-kappa B; Oxidative Stress; Pyridones; Reactive Oxygen Species; Signal Transduction

Hepatocyte death, which can be apoptosis or necrosis depending on the context, is a prominent feature of liver disease. The lectin concanavalin A (ConA) activates immune cells, resulting in inflammatory liver injury and hepatocyte necrosis. In this issue of the JCI, Günther et al. demonstrate that the pseudokinase mixed lineage kinase domain-like protein (MLKL) participates in hepatocyte death in ConA injury and that MLKL-mediated death is independent of the receptor-interacting protein kinase RIPK3. RIPK3 was absent in hepatocytes, and MLKL-deficient mice, but not RIPK3-deficient mice, were protected from ConA-induced liver injury. The authors also present evidence that an unidentified kinase activates MLKL, as RIPK1 bound MLKL but did not phosphorylate it. Moreover, ConA rapidly induced MLKL, mediated by the IFN-γ/STAT1 pathway, while activation and translocation to the plasma membrane required TNF. Increased phospho-MLKL staining in liver biopsies from patients with autoimmune hepatitis suggests a role for MLKL in this disease. This study describes a previously unrecognized form of cell death in the liver that should be further explored as a potential therapeutic target in immune-mediated liver injury.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Autoimmune; Hepatocytes; Humans; Interferon-gamma; Liver; Mice; Mice, Mutant Strains; Necrosis; Protein Kinases; Receptor-Interacting Protein Serine-Threonine Kinases; STAT1 Transcription Factor

Glycolipids are potent activator of natural killer T (NKT) cells. The relationship between NKT cells and intestinal bacterial glycolipids in liver disorders remained unclear. We found that, in sharp contrast to specific pathogen-free (SPF) mice, germ-free (GF) mice are resistant to Concanavalin A (ConA)-induced liver injury. ConA treatment failed to trigger the activation of hepatic NKT cells in GF mice. These defects correlated with the sharply reduced levels of CD1d-presented glycolipid antigens in ConA-treated GF mice compared with SPF counterparts. Nevertheless, CD1d expression was similar between these two kinds of mice. The absence of intestinal bacteria did not affect the incidence of αGalCer-induced liver injury in GF mice. Importantly, we found the intestinal bacteria contain glycolipids which can be presented by CD1d and recognized by NKT cells. Furthermore, supplement of killed intestinal bacteria was able to restore ConA-mediated NKT cell activation and liver injury in GF mice. Our results suggest that glycolipid antigens derived from intestinal commensal bacteria are important hepatic NKT cell agonist and these antigens are required for the activation of NKT cells during ConA-induced liver injury. These finding provide a mechanistic explanation for the capacity of intestinal microflora to control liver inflammation.

Topics: Animals; Antigens, CD1d; Bacterial Proteins; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Gastrointestinal Microbiome; Germ-Free Life; Glycolipids; Intestines; Mice; Natural Killer T-Cells; Specific Pathogen-Free Organisms

Hepatotoxicity of the antidiabetic drug metformin has been reported, but the underlying mechanisms remain unclear. We here investigated the effect of metformin in immune-mediated liver damage. While not hepatotoxic alone, metformin (200 mg/kg) aggravated concanavalin A (Con A, 12 mg/kg)-induced hepatitis, an experimental model of T cell-mediated liver injury, in both relatively resistant BALB/c and highly susceptible C57Bl/6 mice. Metformin + Con A-treated mice had elevated serum levels of pro-inflammatory cytokines TNF-α and IFN-γ, accompanied by a massive mononuclear cell infiltration in the liver. This was associated with the higher numbers of CD4(+) T cells producing TNF-α, IFN-γ and IL-17, CD4(+) T cells expressing chemokine receptor CXCR3 and activation marker CD27, CD4(+)CD62L(-)CCR7(-) and CD8(+)CD62L(-)CCR7(-) effector memory cells, IFN-γ producing NK cells, IL-4 and IL-17 producing NKT cells and IL-12 producing macrophages/dendritic cells. The percentage of CD4(+)CXCR3(+)Tbet(+)IL-10(+) and CD4(+)CD69(+)CD25(-) regulatory T cells was reduced. Metformin stimulated inducible nitric oxide synthase (iNOS) expression in the liver and spleen, and genetic deletion of iNOS attenuated the hepatotoxicity of metformin. Metformin increased the autophagic light chain 3 conversion and mRNA expression of important autophagy-inducing (beclin-1, Atg5 and GABARAP) and pro-apoptotic (p21, p27, Puma, Noxa, Bax, Bad, Bak1, Bim and Apaf1), but not anti-apoptotic molecules (Bcl-xL, survivin and XIAP), which correlated with the apoptotic caspase-3/PARP cleavage in the liver. The autophagy inhibitor chloroquine (20 mg/kg) prevented liver injury and apoptotic changes induced by metformin. Therefore, metformin aggravates immune-mediated hepatitis by promoting autophagy and activation of immune cells, affecting effector, as well as liver-specific regulatory T cells and iNOS expression.

Topics: Animals; Apoptosis; Autophagy; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Flow Cytometry; Hepatocytes; Hypoglycemic Agents; Liver; Male; Metformin; Mice, Inbred BALB C; Mice, Inbred C57BL; Real-Time Polymerase Chain Reaction; T-Lymphocytes

Since reactive oxygen species (ROS) derived from Kupffer cells (KC), especially CD68(+) KC, play a key role in the induction of hepatic oxidative stress and injuries, we developed a polythiolated- and mannosylated human serum albumin (SH-Man-HSA), which functions as a novel nanoantioxidant for delivering thiol to CD68(+) KC. In vitro electron paramagnetic resonance coupled with pharmacokinetics and immunohistochemical studies showed that SH-Man-HSA possessed powerful radical-scavenging activity and rapidly and selectively delivered thiols to the liver via mannose receptor (CD206) on CD68(+) cells. SH-Man-HSA significantly improved the survival rate of concanavalin-A (Con-A)-treated mice. Moreover, SH-Man-HSA exhibited excellent hepatoprotective functions, not by decreasing tumor necrosis factor or interferon-γ production that is closely associated with Con-A-induced hepatitis, but by suppressing ROS production. Interestingly, the protective effect of SH-Man-HSA was superior to N-acetyl cysteine (NAC). This could be attributed to the difference in the inhibition of hepatic oxidative stress between the two antioxidants depending on their potential for thiol delivery to the liver. Similar results were also observed for acetaminophen (APAP)-induced hepatopathy models. Flow cytometric data further confirmed that an increase in F4/80(+)/ROS(+) cells was dramatically decreased by SH-Man-HSA. The administration of SH-Man-HSA at 4 hours following a Con-A or APAP injection also exhibited a profound hepatoprotective action against these hepatitis models, whereas this was not observed for NAC. It can be concluded therefore that SH-Man-HSA has great potential for use in a rescue therapy for hepatopathy as a nanoantioxidant because of its ability to efficiently and rapidly deliver thiols to CD68(+)/CD206(+) KC.

Topics: Acetaminophen; Acute Disease; Albumins; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antioxidants; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Flow Cytometry; Glycoproteins; Kupffer Cells; Lectins, C-Type; Male; Mannose Receptor; Mannose-Binding Lectins; Mice, Inbred C57BL; Nanoparticles; Receptors, Cell Surface

Secreted protein, acidic and rich in cysteine (SPARC) is involved in many biological process including liver fibrogenesis, but its role in acute liver damage is unknown. To examine the role of SPARC in acute liver injury, we used SPARC knock-out (SPARC(-/-)) mice. Two models of acute liver damage were used: concanavalin A (Con A) and the agonistic anti-CD95 antibody Jo2. SPARC expression levels were analyzed in liver samples from patients with acute-on-chronic alcoholic hepatitis (AH). SPARC expression is increased on acute-on-chronic AH patients. Knockdown of SPARC decreased hepatic damage in the two models of liver injury. SPARC(-/-) mice showed a marked reduction in Con A-induced necroinflammation. Infiltration by CD4+ T cells, expression of tumor necrosis factor-α and interleukin-6 and apoptosis were attenuated in SPARC(-/-) mice. Sinusoidal endothelial cell monolayer was preserved and was less activated in Con A-treated SPARC(-/-) mice. SPARC knockdown reduced Con A-induced autophagy of cultured human microvascular endothelial cells (HMEC-1). Hepatic transcriptome analysis revealed several gene networks that may have a role in the attenuated liver damaged found in Con A-treated SPARC(-/-) mice. SPARC has a significant role in the development of Con A-induced severe liver injury. These results suggest that SPARC could represent a therapeutic target in acute liver injury.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Endothelial Cells; Endothelium, Vascular; Gene Knockdown Techniques; Lipopolysaccharides; Liver; Male; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Osteonectin; Transcriptome

N‑Acetylglucosaminyltransferase V (GnT‑V) catalyzes β1‑6 branching in asparagine‑linked oligosaccharides and is one of the most important glycosyltransferases involved in carcinogenesis, cancer metastasis and immunity. To investigate the biological functions of GnT‑V, the present study developed GnT‑V transgenic (Tg) mice and the role of GnT‑V in experimental immune‑mediated hepatitis, induced by concanavalin A (ConA), were investigated. It was found that the aberrant expression of GnT‑V exacerbated ConA‑induced hepatitis in the Tg mice compared with the wild‑type (WT) mice. The survival rate of the ConA‑induced hepatitis at a high‑dose of ConA was significantly lower in the Tg mice. Intravenously injected ConA is known to initially bind predominantly to the mannose gland of the liver sinusoidal endothelial cell (LSEC) surface and to leads to the activation of various immune cells. In the present study, the binding affinity of ConA to the LSECs did not differ between the WT and Tg mice. In addition, T cell receptor stimulation by anti‑cluster of differentiation (CD)3/CD28 antibodies produced lower levels of T helper (Th)1 cytokine (interferon‑γ) and higher levels of Th2 cytokine (interleukin‑10) in the Tg mouse splenic lymphocytes compared with WT mice. The composition of the hepatic mononuclear cells revealed that CD11b‑positive cells were significantly increased in the GnT‑V Tg mice. In addition, F4/80‑positive cells were significantly increased in the Tg mouse liver and the depletion of macrophages reduced the difference in the severity of ConA‑induced hepatitis between the WT and Tg mice. In conclusion, the present findings indicated that the aberrant expression of GnT‑V led to an increase in hepatic macrophage infiltration and enhanced ConA‑induced hepatitis. Modulation of glycosylation may be a novel therapeutic target for immunity‑associated acute hepatitis.

Topics: Animals; Cell Count; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Disease Progression; Galectin 3; Hepatocytes; Liver; Lymphocyte Activation; Macrophages; Male; Mice; Mice, Transgenic; N-Acetylglucosaminyltransferases; Spleen; Th1 Cells; Th2 Cells

Serum amyloid A is a proinflammatory molecule that induces leukocyte infiltration and promotes neutrophil adhesion to endothelial cells under inflammatory conditions. The aim of this study was to examine whether Saa1 aggravates T cell-mediated hepatitis by inducing chemokines in a liver-specific, Saa1-overexpressing, transgenic (TG) mouse model. We generated TG mice in which Saa1 was overexpressed specifically in liver tissue. The chemokines monocyte chemotactic protein 1 (MCP1), MIP1α, MIP1β, interferon γ-induced protein 10 (IP-10), and eotaxin were induced in Saa1 TG mice. After concanavalin A treatment, Saa1 expression was higher in Saa1 TG mice than in WT mice. More severe liver injury, increased hepatocyte apoptosis, and higher levels of hepatic enzymes were observed in Saa1 TG mice than in WT mice. Liver infiltration of CD4(+) T cells and macrophages increased after inducing hepatitis. Activation of T cells was higher in Saa1 TG mice than in WT mice, and the populations of Th17 cells and regulatory T cells were altered by overexpressing Saa1 in TG mice. Secretion of various cytokines, such as interferon γ, tumor necrosis factor α, and interleukin 6, increased in Saa1 TG mice. Injecting a Toll-like receptor 2 (TLR2) antagonist in vivo inhibited chemokine expression and IκBα phosphorylation and showed that the induction of chemokines by Saa1 was dependent on TLR2. Hepatic Saa1 accelerated T cell-mediated hepatitis by inducing chemokine production and activating T cells by TLR2. Therefore, Saa1 might be a novel inflammatory factor that acts as a chemokine modulator in hepatitis.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Inflammation Mediators; Liver; Lymphocyte Activation; Macrophages; Mice; Mice, Transgenic; Mitogens; Serum Amyloid A Protein; T-Lymphocytes, Regulatory; Th17 Cells; Toll-Like Receptor 2

Chronic bowel disease can co-exist with severe autoimmune hepatitis (AIH) in an absence of primary sclerosing cholangitis. Genetic background may contribute to this overlap syndrome. We previously have shown that the deficiency of iPLA2β causes an accumulation of hepatocyte apoptosis, and renders susceptibility for acute liver injury. We here tested whether AIH induction in iPLA2β-null mice could result in intestinal injury, and whether bile acid metabolism was altered. Control wild-type (WT) and female iPLA2β-null (iPLA2β(-/-)) mice were intravenously injected with 10mg/kg concanavalinA (ConA) or saline for 24h. ConA treatment of iPLA2β(-/-) mice caused massive liver injury with increased liver enzymes, fibrosis, and necrosis. While not affecting WT mice, ConA treatment of iPLA2β(-/-) mice caused severe duodenal villous atrophy concomitant with increased apoptosis, cell proliferation, globlet cell hyperplasia, and endotoxin leakage into portal vein indicating a disruption of intestinal barrier. With the greater extent than in WT mice, ConA treatment of iPLA2β(-/-) mice increased jejunal expression of innate response cytokines CD14, TNF-α, IL-6, and SOCS3 as well as chemokines CCL2 and the CCL3 receptor CCR5. iPLA2β deficiency in response to ConA-induced AIH caused a significant decrease in hepatic and biliary bile acids, and this was associated with suppression of hepatic Cyp7A1, Ntcp and ABCB11/Bsep and upregulation of intestinal FXR/FGF15 mRNA expression. The suppression of hepatic Ntcp expression together with the loss of intestinal barrier could account for the observed bile acid leakage into peripheral blood. Thus, enteropathy may result from acute AIH in a susceptible host such as iPLA2β deficiency.

Topics: Animals; Apoptosis; Atrophy; Bile Acids and Salts; Chemical and Drug Induced Liver Injury; Concanavalin A; Duodenum; Female; Gastrointestinal Diseases; Genetic Predisposition to Disease; Goblet Cells; Group VI Phospholipases A2; Hepatitis, Autoimmune; Hyperplasia; Mice; Mice, Knockout; Permeability

Exogenous 1-methylnicotinamide (MNA) displays anti-inflammatory activity. The aim of this work was to characterize the profile of release of endogenous MNA during the initiation and progression of murine hepatitis induced by Concanavalin A (ConA). In particular we aimed to clarify the role of interleukin-6 (IL-6) as well as the energy state of hepatocytes in MNA release in early and late phases of ConA-induced hepatitis in mice. Hepatitis was induced by ConA in IL-6(+/+) and IL-6(-/-) mice, and various parameters of liver inflammation and injury, as well as the energy state of hepatocytes, were analysed in relation to MNA release. The decrease in ATP/ADP and NADH/NAD ratios, cytokine release (IL-6, IFN-ɤ), acute phase response (e.g. haptoglobin) and liver injury (alanine aminotransaminase, ALT) were all blunted in ConA-induced hepatitis in IL-6(-/-) mice as compared to IL-6(+/+) mice. The release of MNA in response to Con A was also significantly blunted in IL-6(-/-) mice as compared to IL-6(+/+) mice in the early stage of ConA-induced hepatitis. In turn, nicotinamide N-methyltransferase (NNMT) and aldehyde oxidase (AO) activities were blunted in the liver and MNA plasma concentration was elevated to similar degree in the late stage after Concanavalin A in IL-6(+/+) and IL-6(-/-) mice. In conclusion, we demonstrated that in ConA-induced hepatitis, early, but not late MNA release was IL-6-dependent. Our results suggest that in the initiation and early hepatitis, MNA release is linked to the energy deficit/impaired redox status in hepatocytes, while in a later phase, MNA release is rather linked to the systemic inflammation.

Topics: Acute-Phase Reaction; Aldehyde Oxidase; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Energy Metabolism; Hepatitis; Hepatocytes; Interleukin-6; Liver Function Tests; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria, Liver; Niacinamide; Nicotinamide N-Methyltransferase

Galangin is an active pharmacological ingredient from propolis and Alpinia officinarum Hance, and has been reported to have anti-inflammatory and antioxidative properties. The present study aims to reveal the effect of galangin on Concanavalin A (ConA)-induced hepatitis (CIH), a well-established animal model of immune-mediated liver injury, and to clarify the related mechanism. C57BL/6 mice were pretreated with galangin followed by ConA challenge. Results indicated that galangin inhibited ConA-induced liver damage. Mice pretreated with galangin showed more reduction of liver damage when compared with control mice pretreated with vehicle solution. In galangin-pretreated mice with induced CIH, increases in serum levels of several inflammatory cytokines, including tumor necrosis factor-α, interferon-γ, and interleukin-12 were dramatically attenuated, and chemokines and adhesion molecules like interferon inducible protein-10, macrophage inflammatory protein-1α, and inter-cellular adhesion molecule-1 messenger RNA expressions in liver were decreased. Moreover, CIH mice pretreated with galangin showed less leukocyte infiltration and T-cell activation in the liver. Further, the mechanism of the anti-inflammatory effects of galangin may be attributed to its modulation of crucial inflammatory signaling pathways, including nuclear factor kappa B and interferon-gamma/signal transducer and activator of transcription 1. Collectively, these findings suggest the preventive and therapeutic potential of galangin in immune-mediated liver injury in vivo.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Cytokines; Enzyme Induction; Flavonoids; Leukocytes; Liver; Male; Mice; Mice, Inbred C57BL; NF-kappa B; STAT1 Transcription Factor

To determine the immune-modulatory and the hepatoprotective effects of oral administration of two soy extracts in immune mediated liver injury and non-alcoholic steatohepatitis (NASH).. Two soy extracts, M1 and OS, were orally administered to mice with concanavalin A (ConA) immune-mediated hepatitis, to high-fat diet (HFD) mice and to methionine and choline reduced diet combined with HFD mice. Animals were followed for disease and immune biomarkers.. Oral administration of OS and M1 had an additive effect in alleviating ConA hepatitis manifested by a decrease in alanine aminotransferase and aspartate aminotransferase serum levels. Oral administration of the OS and M1 soy derived fractions, ameliorated liver injury in the high fat diet model of NASH, manifested by a decrease in hepatic triglyceride levels, improvement in liver histology, decreased serum cholesterol and triglycerides and improved insulin resistance. In the methionine and choline reduced diet combined with the high fat diet model, we noted a decrease in hepatic triglycerides and improvement in blood glucose levels and liver histology. The effects were associated with reduced serum tumor necrosis factor alpha and alteration of regulatory T cell distribution.. Oral administration of the combination of OS and M1 soy derived extracts exerted an adjuvant effect in the gut-immune system, altering the distribution of regulatory T cells, and alleviating immune mediated liver injury, hyperlipidemia and insulin resistance.

Topics: Administration, Oral; Animals; Biomarkers; Blood Glucose; Chemical and Drug Induced Liver Injury; Choline Deficiency; Concanavalin A; Cytoprotection; Diet, High-Fat; Disease Models, Animal; Glycine max; Immunologic Factors; Insulin; Insulin Resistance; Lipids; Liver; Metabolic Syndrome; Methionine; Mice; Non-alcoholic Fatty Liver Disease; Plant Extracts; T-Lymphocytes, Regulatory; Time Factors; Tumor Necrosis Factor-alpha

Dietary n-3 polyunsaturated fatty acids (PUFA) exert anti-inflammatory and immunoregulatory effects through down-regulating the innate and adoptive immune response. However, the effect of dietary n-3 PUFA on CD4+CD25+ regulatory T cells (Tregs) is unclear.. The current study was to examine the relationship between n-3 PUFA and Tregs as well as their immunoregulatory effect in immune-mediated liver injury.. The mice model feeding with n-3 PUFA-enriched diet was established and Tregs were analyzed. Effect of docosahexaenoic acid (DHA) on Tregs proliferation and induction was determined in vitro. The potential immunotherapeutic effect of dietary n-3 PUFA was investigated through Con A-induced hepatitis model.. Long-term administration of dietary n-3 PUFA significantly increased hepatic Tregs and modulated their phenotype. n-3 PUFA or DHA directly increased natural Tregs (nTreg) proliferation but didn't increase inducible Tregs (iTreg). In addition, the expression of peroxisome proliferator activated receptor gamma (PPAR-γ), transforming growth factor β (TGF-β) and interleukin (IL)-10 were significantly up-regulated in n-3 PUFA-enriched diet-fed mice. Finally, n-3 PUFA-enriched diet alleviated liver injury induced by Con A and down-regulated pro-inflammatory cytokines expression, accompanied by increased PPAR-γ expression.. Dietary n-3 PUFA enhanced Tregs generation through up-regulating PPAR-γ and TGF-β expression, and protected mice from Con A-induced liver injury. This finding provides a promising potential therapeutic method in treating inflammatory and autoimmune disease.

Topics: Animals; Cell Proliferation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Dietary Fats, Unsaturated; Fatty Acids, Omega-3; Liver; Male; Mice; Mice, Inbred C57BL; PPAR gamma; Signal Transduction; T-Lymphocytes, Regulatory

It is well established that macrophage infiltration is involved in concanavalin A (conA)-induced liver injury. However, the role of macrophages in conA-induced renal injury remains unknown. The aims of this study were to investigate macrophage infiltration in conA-induced renal injury and determine whether paeoniflorin (PF) could inhibit macrophage infiltration into the kidney.. BALB/C mice were pre-treated with or without PF 2 h (h) before conA injection. At 8 h after con A injection, all the mice were sacrificed; The liver and kidney histology were studied. The renal CD68 expression was detected by immunohistochemical and real-time PCR analysis. The level of expression of C-X-C chemokine receptor type 3 (CXCR3) was analyzed by western blot, immunohistochemical and real-time PCR. The pathophysiological involvement of CXCR3 in macrophage infiltration were investigated using dual-colour immunofluorescence microscopy.. PF administration significantly reduced the elevated serum levels of alanine transaminase (ALT), blood urea nitrogen (BUN), creatinine (Cr) and the severity of liver and renal damage compared with that in the conA-vehicle group. PF administration inhibited the increase in renal IL1β mRNA expression and concentration. Furthermore, immunohistochemical analysis showed that macrophages secreted CXCR3 in the kidneys of the conA-vehicle mice. Immunofluorescence microscopy demonstrated CXCR3 bound tightly to C-X-C motif ligand 11 (CXCL11) in the kidneys of the conA-vehicle mice and showed that PF treatment could suppress CXCR3/CXCL11 over-activation.. Macrophage infiltration was a notable pathological change in the kidneys of conA-treated mice. PF administration attenuated conA-induced renal damage, at least in part, by inhibiting the over-activated CXCR3/CXCL11 signal axis.

Topics: Acute Kidney Injury; Animals; Anti-Inflammatory Agents, Non-Steroidal; Blotting, Western; Chemical and Drug Induced Liver Injury; Chemokine CXCL11; Concanavalin A; Disease Models, Animal; Female; Glucosides; Immunohistochemistry; Kidney; Macrophages; Mice; Mice, Inbred BALB C; Microscopy, Fluorescence; Monoterpenes; Real-Time Polymerase Chain Reaction; Receptors, CXCR3

Autologous transplantation of mesenchymal stem cells (MSCs) reduces concanavalin A (Con A)-induced hepatic injury in mice. However, the mechanism is unclear and the therapeutic effect of allo-transplantation remains unknown. Our aim was to investigate the effects and mechanisms related to allo-transplantation of MSCs when used to treat Con A hepatic injury.. After Con A-induced liver injury was created in C57BL/6J mice, MSCs derived from BALB/c mice or a vehicle control was administered.. Allo-transplantation of MSCs derived from BALB/c mice attenuated hepatic apoptosis in C57BL/6J mice that had undergone Con A-induced liver injury. MSCs increased the level of serum interleukin (IL)-10 and the phosphorylation of hepatic STAT3, but decreased the level of hepatic IFN-γ and phospho-STAT1. Notably, the administered MSCs were trapped mostly in the lungs and promoted the macrophage M2 switch, which contributed to the increased IL10 levels in the lungs and serum. Loss of the therapeutic effect was observed after knock-down of the expression of interleukin 1 receptor antagonist (IL1Ra) in the MSCs. In vitro investigation supported the hypothesis that MSCs are able to switch Con A-stimulated macrophages to the M2 phenotype, which results in an increase in IL10 production.. Allo-transplantation of MSCs reduces Con A liver injury by increasing IL10 production through an IL1Ra dependent macrophage switch.

Topics: Allografts; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Gene Knockdown Techniques; Interferon-gamma; Interleukin 1 Receptor Antagonist Protein; Interleukin-10; Liver; Lung; Macrophages; Macrophages, Alveolar; Male; Mesenchymal Stem Cell Transplantation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Phenotype; STAT1 Transcription Factor; STAT3 Transcription Factor

Ghrelin is a 28-amino-acid gut hormone that was first discovered as a potent growth hormone secretagogue. Recently, it has been shown to exert a strong anti-inflammatory effect. The purpose of the study reported here was to explore the effect and mechanism of ghrelin on concanavalin (Con) A-induced acute hepatitis.. Balb/C mice were divided into four groups: normal control (NC) (mice injected with vehicle [saline]); Con A (25 mg/kg); Con A + 10 μg/kg ghrelin; and Con A + 50 μg/kg ghrelin (1 hour before Con A injection). Pro-inflammatory cytokine levels were detected. Protein levels of phosphoinositide 3-kinase (PI3K); phosphorylated Akt (p-Akt); caspase 3, 8, and 9; and microtubule-associated protein 1 light chain 3 (LC3) were also detected. Perifosine (25 mM) (an Akt inhibitor) was used to investigate whether the protective effect of ghrelin was interrupted by an Akt inhibitor. Protein levels of p-AKT; Bcl-2; Bax; and caspase 3, 8, and 9 were also detected.. Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by ghrelin pretreatment in Con A-induced hepatitis. Inflammatory cytokines were significantly reduced by ghrelin pretreatment. Bcl-2; Bax; and caspase 3, 8, and 9 expression were also clearly affected by ghrelin pretreatment, compared with the Con A-treated group. However, the Akt kinase inhibitor reversed the decrease of Bax and caspase 3, 8, 9, and reduced the protein level of p-Akt and Bcl-2. Ghrelin activated the PI3K/Akt/Bcl-2 pathway and inhibited activation of autophagy.. Our results demonstrate that ghrelin attenuates Con A-induced acute immune hepatitis by activating the PI3K/Akt pathway and inhibiting the process of autophagy, which might be related to inhibition of inflammatory cytokine release, and prevention of hepatocyte apoptosis. These effects could be interrupted by an Akt kinase inhibitor.

Topics: Animals; Anti-Infective Agents; Apoptosis; Apoptosis Regulatory Proteins; Autophagy; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Cytoprotection; Disease Models, Animal; Ghrelin; Inflammation Mediators; Liver; Mice, Inbred BALB C; Necrosis; Signal Transduction; Time Factors

Retinols are metabolized into retinoic acids by alcohol dehydrogenase (ADH) and retinaldehyde dehydrogenase (Raldh). However, their roles have yet to be clarified in hepatitis despite enriched retinols in hepatic stellate cells (HSCs). Therefore, we investigated the effects of retinols on Concanavalin A (Con A)-mediated hepatitis. Con A was injected into wild type (WT), Raldh1 knock-out (Raldh1(-/-)), CCL2(-/-) and CCR2(-/-) mice. For migration study of regulatory T cells (Tregs), we used in vivo and ex vivo adoptive transfer systems. Blockade of retinol metabolism in mice given 4-methylpyrazole, an inhibitor of ADH, and ablated Raldh1 gene manifested increased migration of Tregs, eventually protected against Con A-mediated hepatitis by decreasing interferon-γ in T cells. Moreover, interferon-γ treatment increased the expression of ADH3 and Raldh1, but it suppressed that of CCL2 and IL-6 in HSCs. However, the expression of CCL2 and IL-6 was inversely increased upon the pharmacologic or genetic ablation of ADH3 and Raldh1 in HSCs. Indeed, IL-6 treatment increased CCR2 expression of Tregs. In migration assay, ablated CCR2 in Tregs showed reduced migration to HSCs. In adoptive transfer of Tregs in vivo and ex vivo, Raldh1-deficient mice showed more increased migration of Tregs than WT mice. Furthermore, inhibited retinol metabolism increased survival rate (75%) compared with that of the controls (25%) in Con A-induced hepatitis. These results suggest that blockade of retinol metabolism protects against acute liver injury by increased Treg migration, and it may represent a novel therapeutic strategy to control T cell-mediated acute hepatitis.

Topics: Alcohol Dehydrogenase; Animals; Cell Differentiation; Cell Movement; Cell Survival; Chemical and Drug Induced Liver Injury; Chemokine CCL2; Concanavalin A; Fomepizole; Hepatic Stellate Cells; Interferon-gamma; Interleukin-6; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Pyrazoles; T-Lymphocytes, Regulatory; Tretinoin; Vitamin A

To explore the protective effect and its mechanism of B7-H4 on the immuno hepatic injury.. The immuno hepatic injury was induced by Concanavalin A (Con A). Sixty KM mice were randomly divided into 4 groups with 15 mice in each group: Group A (saline), Group B (pcDNA3.1-mB7-H4-Fc), Group C (pcDNA3.1), Group D (Con A). One day before the injection of Con A (25 mg/kg), the mice in Group B and Group C received the injection of 100 pg pcDNA3.1-mB7-H4-Fc and 100 microg pcDNA3.1 respectively. The blood samples were collected at 12 h, 24 h and 48 h after Con A injection, the levels of ALT, AST, IL-4 and IFN-gamma were measured. Five mice in each group were sacrificed at the above 3 time points, the liver tissue were harvested for histopathological detection.. After Con A injection, the level of ALT in Group B, C, and D were higher than that in Group A. The level of ALT in Group B was lower than that in Group C and D. The significant difference was found between Group B and Group C. The hepatic injury of Group B was less serious than that of Group C and D.. B7-H4 may have protection on the immune injury of liver induced by Con A.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Mice; Protective Agents; V-Set Domain-Containing T-Cell Activation Inhibitor 1

Prednisolone is a corticosteroid that has been used to treat inflammatory liver diseases such as autoimmune hepatitis and alcoholic hepatitis. However, the results have been controversial, and how prednisolone affects liver disease progression remains unknown. In the current study we examined the effect of prednisolone treatment on several models of liver injury, including T/NKT cell hepatitis induced by concanavalin A (ConA) and α-galactosylceramide (α-GalCer), and hepatotoxin-mediated hepatitis induced by carbon tetrachloride (CCl4 ) and/or ethanol. Prednisolone administration attenuated ConA- and α-GalCer-induced hepatitis and systemic inflammatory responses. Treating mice with prednisolone also suppressed inflammatory responses in a model of hepatotoxin (CCl4 )-induced hepatitis, but surprisingly exacerbated liver injury and delayed liver repair. In addition, administration of prednisolone also enhanced acetaminophen-, ethanol-, or ethanol plus CCl4 -induced liver injury. Immunohistochemical and flow cytometric analyses demonstrated that prednisolone treatment inhibited hepatic macrophage and neutrophil infiltration in CCl4 -induced hepatitis and suppressed their phagocytic activities in vivo and in vitro. Macrophage and/or neutrophil depletion aggravated CCl4 -induced liver injury and impeded liver regeneration. Finally, conditional disruption of glucocorticoid receptor in macrophages and neutrophils abolished prednisolone-mediated exacerbation of hepatotoxin-induced liver injury.. Prednisolone treatment prevents T/NKT cell hepatitis but exacerbates hepatotoxin-induced liver injury by inhibiting macrophage- and neutrophil-mediated phagocytic and hepatic regenerative functions. These findings may not only increase our understanding of the steroid treatment mechanism but also help us to better manage steroid therapy in liver diseases.

Topics: Animals; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Galactosylceramides; Glucocorticoids; Killer Cells, Natural; Liver Regeneration; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Neutrophils; Prednisolone; T-Lymphocytes

The aryl hydrocarbon receptor (AhR), a ligand-activated nuclear transcription factor, is known to mediate the toxic and carcinogenic effects of various environmental pollutants, while AhR has been shown to protect animals from various types of tissue injury. ConA-induced hepatitis is known as a mouse model of acute liver injury. Here, we found a protective role of AhR in ConA-induced hepatitis. AhR is induced in the liver during ConA-induced hepatitis, and Ahr (-/-) mice were highly sensitive to this model. Bone marrow chimera experiments indicate that Ahr (-/-) hematopoietic cells are responsible for hypersensitivity to ConA-induced hepatitis. We found that IFN-γ from invariant NKT cells was up-regulated and IL-22 from innate lymphoid cells (ILCs) was abolished in Ahr (-/-) mice. In addition, IL-22 production was still observed in Rag2 (-/-) mice but it was severely reduced in Ahr (-/-) Rag2 (-/-) mice. ConA-induced IL-22 production was also dependent on retinoic acid-related orphan receptor γt. These results show that AhR has crucial protective roles in ConA-induced liver injury via promoting IL-22 production from ILCs and suppressing IFN-γ expression from NKT cells.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Disease Progression; DNA-Binding Proteins; Gene Expression Regulation; Humans; Interferon-gamma; Interleukin-22; Interleukins; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Nuclear Receptor Subfamily 1, Group F, Member 3; Receptors, Aryl Hydrocarbon; Transplantation Chimera

It is becoming increasingly clear that the T-cell-mediated immune response is important in many diseases. In this study, we used concanavalin A (Con A) -induced hepatitis to investigate the role of CD49a in the molecular and cellular mechanism of the T-cell-mediated immune response. We found that CD49a(-/-) mice had significantly reduced levels of serum alanine aminotransferase and were protected from Con A-induced hepatitis. CD49a deficiency led to decreased production of interferon-γ (IFN-γ) and interleukin-17A (IL-17A) after Con A injection. Furthermore, we found that hepatic CD4(+) T cells and invariant natural killer T cells up-regulated CD49a expression, along with enhanced activation after Con A injection, leading to production of inflammatory cytokines by these T cells. Blockade of CD49a in vivo ameliorated Con A-induced hepatitis with reduced production of IFN-γ and IL-17A. Hence, CD49a promoted Con A-induced hepatitis through enhancing inflammatory cytokine production (IFN-γ and IL-17A) by CD4(+) T and invariant natural killer T cells. The protective effect of CD49a blockade antibody suggested a new target therapeutic molecule for intervention of T-cell-mediated liver injury.

Topics: Alanine Transaminase; Animals; Biomarkers; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Immunity, Cellular; Inflammation Mediators; Integrin alpha1; Interferon-gamma; Interleukin-17; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Th1 Cells; Time Factors

Malignant transformation of hepatocellular carcinoma (HCC) occurs through repetitive liver injury in a context of inflammation and oxidative DNA damage. A spectrum of natural sesquiterpenoids from curcuma oil has displayed antioxidant, anti-inflammatory and anti-carcinogenic properties. The aim of the study was to investigate the hepatoprotective and anti-HCC effects of curcuma oil in vivo and in vitro. Mice were pretreated with curcuma oil (100 mg/kg) for 3 days, then treated with Concanavalin A (30 mg/kg). The hepatic tissue was evaluated for histology, CD4+ cell, interferon-γ, apoptosis, lipid peroxidation, 8-hydroxy-deoxyguanosine and MnSOD. C57L/J mice were treated with curcuma oil and 107 Hepa1-6 cells directly inoculated into liver lobes. The effects of curcuma oil on cell growth and cell death were evaluated. In addition, MnSOD, HSP60, catalase, NF-κB and caspase-3 were also investigated in the Hepa1-6 cells treated with curcuma oil. Pretreatment with curcuma oil significantly attenuates inflammation and oxidative damage by Concanavalin A. Treatment with curcuma oil can decrease the incidence of HCC. Curcuma oil inhibits cell growth and induces cell death in Hepa1-6 cells. Curcuma protected mice with hepatic injury from inflammatory and oxidative stress. Curcuma oil can inhibit hepatoma cell growth in vivo and in vitro.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Hepatocellular; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Curcuma; Fluorescent Antibody Technique; Gas Chromatography-Mass Spectrometry; Humans; Immunoenzyme Techniques; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Mitogens; Oxidative Stress; Plant Extracts; Tumor Cells, Cultured

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compound present in green tea and has been shown to possess anti-inflammatory and anti-oxidative properties. In this study, we investigated the protective effects of EGCG against concanavalin A (ConA)-induced liver injury and the underlying mechanisms. EGCG (5 mg/kg) was administered orally by gavage to mice twice daily for 10 days before an intravenous injection of ConA. We found that EGCG effectively rescued lethality, improved hepatic pathological damage, and decreased serum levels of alanine aminotransaminase (ALT) in ConA-challenged mice. Furthermore, EGCG also significantly prevented the release of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-4, and IL-6 in serum, reduced malondialdehyde (MDA) levels, and restored glutathione (GSH) content and superoxide dismutase (SOD) activity in liver tissues from ConA-challenged mice. Finally, nuclear factor (NF)-κB activation and expression levels of Toll-like receptor (TLR) 2, TLR4 and TLR9 protein in liver tissues were significantly inhibited by EGCG pretreatment. Taken together, our data suggest that EGCG possesses hepatoprotective properties against ConA-induced liver injury through its anti-inflammatory and anti-oxidant actions.

Topics: Animals; Catechin; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Male; Mice, Inbred C57BL; Oxidative Stress; Toll-Like Receptors; Tumor Necrosis Factor-alpha

To clarify the relationship between arginine metabolism and hepatic injury, metabolomic analysis was performed in rats treated with 3 representative hepatotoxicants, monocrotaline (MCT), concanavalin A (ConA), and α-naphthyl isothiocyanate (ANIT); or a myotoxicant, tetramethyl-p-phenylenediamine (TMPD). A single dose of MCT, ConA, or ANIT dose-dependently induced hepatocellular necrosis accompanied by decreased blood arginine and increased blood alanine aminotransferase (ALT) and arginase. A close correlation was detected between arginine and ALT (r = -0.746, -0.795, -0.787 for MCT, ConA, ANIT, respectively) or between arginine and arginase (r = -0.605, -0.808, -0.672 for MCT, ConA, ANIT, respectively) in all three hepatic injury models. In contrast, neither hepatocellular necrosis nor alterations in arginine were found in the skeletal muscle injury model, although ALT was slightly increased. An in vitro assay revealed that blood samples obtained from ConA-treated rats transformed external arginine to ornithine, and the reaction was totally inhibited by an arginase inhibitor. These results suggest that blood arginase plays a crucial role in arginine metabolism associated with hepatic injury. In metabolomic analysis, nearly 450 endogenous metabolites were identified in blood obtained from all the models. Among the 13 metabolites involved in arginine metabolism, decreased arginine and increased ornithine occurred in common in the hepatic injury models, whereas citrulline and other metabolites were not altered. These results indicate that arginine metabolism, especially the arginine-to-ornithine pathway, is altered in association with acute hepatic injury. Furthermore, blood arginine and ornithine are possibly specific biomarkers for hepatic injury.

Topics: Alanine Transaminase; Animals; Arginase; Arginine; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Isocyanates; Male; Metabolomics; Monocrotaline; Naphthalenes; Ornithine; Rats; Rats, Inbred F344; Tetramethylphenylenediamine

Ethyl pyruvate (EP), a potent reactive oxygen species scavenger, has been reported to contribute to the inflammatory process. However, the protective effect of ethyl pyruvate on Concanavalin A (Con A)-induced autoimmune hepatitis have not been explored. Thus, the aims of this study are to investigate both the effects of ethyl pyruvate and its mechanism of protection on Con A-induced autoimmune hepatitis in mice.. Acute autoimmune hepatitis was induced by Con A (20 mg/kg) in Balb/C mice; ethyl pyruvate (40 mg/kg and 80 mg/kg) was administrated 1h prior to the Con A injection. At 3h, 6h and 24h post Con A injection, histological grading, proinflammatory cytokine levels and nuclear factor kappa B (NF-κB) activity were determined.. Following Con A challenge, cytokines TNF-α, IL-2, IL-1β and IL-6 were expressed at 3h and 6h, and the level of HMGB1 significantly increased by 24h. Pretreatment with ethyl pyruvate ameliorated the pathological effects of Con A-induced autoimmune hepatitis and significantly decreased the levels of TNF-α, IL-2, IL-6 and IL-1β at 3h and 6h and the level of HMGB1 at 6h and 24h post injection. Ethyl pyruvate blocked the degradation of IκB α and IκB β and decreased the expression of NF-κB at 24h.. Taken together, these results indicated that ethyl pyruvate protected against Con A-induced autoimmune hepatitis by decreasing both early (TNF-α, IL-2, IL-1β and IL-6) and late (HMGB1) cytokine expression in mice. The reduction of HMGB1 may correlate with the amelioration of NF-κB activity.

Topics: Animals; Blotting, Western; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Autoimmune; HMGB1 Protein; Immunoenzyme Techniques; Interleukin-2; Interleukin-6; Male; Mice; Mice, Inbred BALB C; Mitogens; NF-kappa B; Pyruvates; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha

We studied the relationship between hypoxia and microRNA-210 (miR-210) levels, the miR-210 levels in patients with hepatitis B and the roles of miR-210 in liver inflammation. We used the concanavalin A (Con A) murine hepatitis model and inflammation, hypoxia and miR-210 levels were examined. In these patients, we studied serum miR-210 levels and clinical indexes related to hepatitis in 90 patients with different stages of chronic hepatitis B and 30 controls. Two functional assays of miR-210 in vitro under hypoxic condition were conducted. The animal experiments indicated that the liver and serum miR-210 levels significantly increased with liver hypoxia and inflammation. In humans, serum miR-210 levels enhanced with hepatitis severity and were related to serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TB) and prothrombin activity (PTA) levels. The miR-210 functional assays showed that miR-210 elevation might be related to the decreases in HepG2.2.15 cell dehydrogenase activity and HBV replication under hypoxic conditions. Because the liver inflammation causes liver hypoxia which also results in liver and serum miR-210 level elevation, the serum miR-210 level may serve as a molecular biomarker for the severity of hepatitis and increases in liver miR-210 that we see may be a response of hepatocytes to hypoxia during hepatitis progression.

Topics: Adult; Alanine Transaminase; Animals; Aspartate Aminotransferases; Bilirubin; Biomarkers; Cell Line, Tumor; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Disease Progression; Female; Hepatitis B virus; Hepatitis B, Chronic; Humans; Hypoxia; Liver; Male; Mice; Mice, Inbred BALB C; MicroRNAs; Middle Aged; Prothrombin; Specific Pathogen-Free Organisms; Virus Replication

The development of hepatitis is associated with the infiltration and activation of immune cells in liver. N-3 polyunsaturated fatty acids (n-3 PUFAs) rich fish oil (FO) is used to prevent and treat inflammatory diseases. But, the effects of dietary FO on autoimmune hepatitis remain largely unknown. In this study, Concanavalin A (Con A) induced hepatitis was used to evaluate the actions of dietary FO. Unexpectedly, 2-week FO treatment had not shown any protection, on the contrary, exacerbated liver injury in this hepatitis model. The levels of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) statistically increased from 10,501 ± 2,154 and 30,394 ± 2,420 in low fat diet (LFD)/Con A group to 17,579 ± 693 and 49,439 ± 4,628 in FO/Con A group. Simultaneously, FO diet induced more necrotic liver tissues and apoptotic hepatocytes, and up-regulated the hepatic expression of TNF-α and IFN-γ after Con A challenge. Interestingly, FO promoted severe liver injury was accompanied by decreasing the percentage of CD4⁺ T cell, NK1.1⁺ cells and CD8⁺ T cells in CD45⁺ liver non-parenchymal hepatic cells (NPCs) through inducing apoptosis. Further experiments declared 2-week FO diet intake firstly increased the proportion of CD11b⁺Gr-1(hi) neutrophils in liver, but then dramatically expanded CD11b⁺Gr-1(int) inflammatory monocytes population after Con A administration. Collectively, our study indicated that high FO intake not only aggravated liver injury, but also altered the population of immune cells in liver. Thus, these results indicated that when dietary FO was used to benefit health in autoimmune diseases, its potential risks of side effect also need paying close attention.

Topics: Alanine Transaminase; Animals; Apoptosis; CD11b Antigen; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Dietary Supplements; Disease Models, Animal; Fatty Acids, Omega-3; Fish Oils; Hepatitis, Autoimmune; Hepatocytes; Hydro-Lyases; Interferon-gamma; Killer Cells, Natural; Leukocyte Common Antigens; Liver; Male; Mice; Mice, Inbred C57BL; Neutrophils; Tumor Necrosis Factor-alpha

To investigate the role played by γδ T cells in acute liver injury using the concanavalin A (ConA)-induced liver injury mouse model.. Acute liver injury was induced by intravenous injection of 10 mug/g of ConA into male C57BL/6J mice with wild-type or T cell receptor-γ knockout (TCR δ-/-) genetic backgrounds. Mice injected with PBS alone served as negative controls. The degree of liver damage was assessed by measuring serum levels of transaminase and cytokines at post-injection hours 3, 6, 12, 24, 48, and 72. The percentage of γδ T cells and proportions of different subsets in liver lymphocytes were measured by flow cytometry.. The TCR δ-/- mice showed significantly higher levels of the inflammatory cytokines IFN-γ, TNFα and IL-4 than the wild-type mice at post-injection hour 3. The percentage of liver γδ T cells increased with increased injury degree, and the extent of increase was significantly higher in the TCR δ-/- mice than the wild-type mice (post-injection hour 6: 6302.61+/-592.06 vs. 1319.26+/-355.48, 12: 6569.44+/-1060.98 vs. 3415.53+/-343.90, 24: 6514.29+/-757.26 vs. 2062.73+/-365.67, 48: 1262.61+/-558.07 vs. 113.66+/-113.26, and 72: 226.54+/-98.20 vs. 42.35+/-21.51 U/L; all P less than 0.05). In addition, compared to the negative control mice, the ConA-induced mice showed a higher proportions of Vγ4 γδ T cells to total γδ T cells (17.78+/-2.95 vs. 25.26+/-2.43) and to total liver lymphocytes (0.47+/-0.07 vs. 0.66+/-0.05). Similarly, compared to the negative control mice, the ConA-induced mice showed a higher proportion of Vγ1 γδ T cells to total γδ T cells (38.37+/-6.10 vs. 50.19+/-5.52) but the proportion to total liver lymphocytes was not significantly different among the groups (0.76+/-0.18 vs. 0.78+/-0.25). Reinfusion of Vγ4 γδ T lymphocytes into TCR δ-/- mice led to lower serum ALT levels than reinfusion of Vγ1 γδ T lymphocytes (5054.10+/-1748.51 vs. 12333.56+/-663.535 U/L).. γδ T cells play a protective role in ConA-induced liver injury and this effect maybe mediated by the Vγ4 γδ T cell subset.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-4; Liver; Male; Mice; Mice, Inbred C57BL; Receptors, Antigen, T-Cell, gamma-delta; T-Lymphocyte Subsets; Tumor Necrosis Factor-alpha

Liver eosinophilia has been associated with incidences of drug-induced liver injury (DILI) for more than 50 years, although its role in this disease has remained largely unknown. In this regard, it was recently shown that eosinophils played a pathogenic role in a mouse model of halothane-induced liver injury (HILI). However, the signaling events that drove hepatic expression of eosinophil-associated chemokines, eotaxins, eosinophil infiltration, and subsequent HILI were unclear. We now provide evidence implicating hepatic epithelial-derived cytokine thymic stromal lymphopoietin (TSLP) and type 2 immunity, in particular, interleukin-4 (IL-4) production, in mediating hepatic eosinophilia and injury during HILI. TSLP was constitutively expressed by mouse hepatocytes and increased during HILI. Moreover, the severity of HILI was reduced in mice deficient in either the TSLP receptor (TSLPR) or IL-4 and was accompanied by decreases in serum levels of eotaxins and hepatic eosinophilia. Similarly, concanavalin A-induced liver injury, where type 2 cytokines and eosinophils play a significant role in its pathogenesis, was also reduced in TSLPR-deficient mice. Studies in vitro revealed that mouse and human hepatocytes produce TSLP and eotaxins in response to treatment with combinations of IL-4 and proinflammatory cytokines IL-1β and tumor necrosis factor alpha.. This report provides the first evidence implicating roles for hepatic TSLP signaling, type 2 immunity, and eosinophilia in mediating liver injury caused by a drug.

Topics: Anesthetics, Inhalation; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Halothane; Hepatitis, Animal; Hepatocytes; Humans; Interleukin-4; Mice, Inbred BALB C; Thymic Stromal Lymphopoietin

STAT4, which is activated mainly by IL-12, promotes inflammatory responses by inducing Th1 and Th2 cytokines. Recent genome-wide association studies indicate that STAT4 gene variants are associated with risk of various types of liver diseases, but how STAT4 contributes to liver disease pathogenesis remains obscure. In this study, STAT4 activation was detected in liver immune cells from patients with viral hepatitis and autoimmune hepatitis, as well as in a mouse model of concanavalin A (Con A)-induced hepatitis. Such STAT4 activation was detected mainly in T cells, natural killer T cells, and macrophages and Kupffer cells, and was diminished in Il12a(-/-) and Il12b(-/-) mice. As expected, disruption of the Stat4 gene reduced production of Th1 and Th2 cytokines, but surprisingly exacerbated Con A-induced liver injury. Similarly, disruption of Il12a or Il12b also augmented Con A-induced hepatocellular damage. Further studies showed that hepatic natural killer T (NKT) cells from Con A-treated Stat4(-/-) mice had higher levels of FasL expression and increased cytotoxicity against hepatocytes than those from Con A-treated WT mice. In vitro, blocking FasL attenuated Stat4(-/-) NKT cytotoxicity against hepatocytes. In conclusion, despite up-regulation of proinflammatory cytokines, STAT4 protects against acute T-cell hepatitis, which is mediated by direct or indirect down-regulation of FasL expression on NKT cells.

Topics: Acute Disease; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatocytes; Interleukin-12 Subunit p35; Mice; Mice, Knockout; Mitogens; Natural Killer T-Cells; STAT4 Transcription Factor

Toll-like receptor (TLRs) is a type of pattern-recognition receptor that recognizes pathogen-associated molecular patterns, the important mediator of innate immunity. The aim of this study was to examine the anti-inflammatory effect of TLR2 monoclonal antibody (TLR2 mAb) on concanavalin A (ConA) induced-hepatitis. Our in vitro findings indicated that the TLR2 monoclonal antibody developed by us was able to neutralize the activation of peripherial blood mononucleated cells (PBMC) induced by ConA. Furthermore, pretreatment of mice with TLR2 antibody exerted liver protection against ConA. Compared with the isotype IgG group, the TLR2-antibody-treated group demonstrated less mortality with concomitant decreased serum level of Ast and Alt. The detailed mechanisms underlying the protection effect induced by TLR2 antibody was due to inhibition of infiltration of lymphocytes in liver induced by ConA as well as the expression of pro-inflammatory factors, such as TNF-α, IFN-γ, IL-6. Taken together, our findings demonstrated that TLR2 mAb pretreatment protected liver against ConA-induced hepatitis in mice, suggesting that TLR2 mAb is a potential candidate for therapy of acute hepatitis.

Topics: Animals; Antibodies, Blocking; Cell Movement; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Humans; Immunotherapy; Inflammation Mediators; Mice; Mice, Inbred BALB C; Models, Animal; Toll-Like Receptor 2

Hesperidin (HDN) is a citrus bioflavonoid, which widely exists in many plants. Previous researches have proved that HDN has several functions such as anti-oxidant, anti-tumor, anti-inflammatory, immune regulation and so on. In the present study, we explored the protective effects of HDN on concanavalin A (Con A)-induced hepatic injury. Acute hepatic injury model was established successfully by intravenous administration of Con A (15 mg/kg) in male C57BL/6 mice, and HDN was pretreated for 10 days before Con A challenge. It was found that the hepatic injury was notably improved in HDN pretreated mice. Furthermore, hepatic oxidative stress and the production of proinflammatory cytokines including TNF-α and IFN-γ were decreased by HDN pretreatment. More importantly, compared with Con A-treated mice, the expression and releasing of HMGB1 and T-cell activation were markedly reduced in HDN pretreated mice. Thus, these results suggest that HDN protects mice from Con A-induced hepatic injury by suppressing hepatocyte oxidative stress, producing cytokines, expressing and releasing HMGB1 and activating T cells.

Topics: Animals; Anti-Inflammatory Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatocytes; Hesperidin; HMGB1 Protein; Interferon-gamma; Liver; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Protective Agents; T-Lymphocytes; Tumor Necrosis Factor-alpha

Tumor necrosis factor alpha (TNF-α) plays an important role in the pathogensis of hepatitis C virus (HCV) infection induced liver injury. This study aimed to evaluate the effects of TNF-α inhibition with pentoxifylline (PTX) on concanavalin A (Con A)-induced hepatic injury in rats. The rats were distributed among 3 groups: (i) control group (1 mL saline·week(-1) by intravenous injection (i.v.)); (ii) Con A treatment group (20 mg Con A·(kg body mass)(-1)·week(-1), i.v.), and (iii) rats treated with Con A and with PTX (200 mg PTX·(kg body mass)(-1)·day(-1), per oral) group. Blood samples and livers were collected at the end of weeks 1, 2, 4, and 8 of Con A treatment. Portal pressure (PP) was measured at the end of week 8. The administration of PTX was found to confer significant protection against the injurious effects of Con A on the liver, by reducing serum levels of aspartate aminotransferase, alanine aminotransferase, hepatic TNF-α, and malondialdehyde. Histopathological examination revealed that treatment with PTX significantly suppressed early inflammation, reduced alpha smooth muscle actin, and the apoptosis of hepatocytes induced by Con A. Moreover, PTX significantly (P < 0.05) reduced PP, and quantitative analyses of the area of fibrosis induced by treatment with Con A showed a significant reduction at the end of week 8. We conclude that rats treated with PTX revealed a more or less normal hepatocyte architecture as well as marked improvement in fibrosis and PP.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Fibrosis; Hepatocytes; Image Processing, Computer-Assisted; Liver; Malondialdehyde; Pentoxifylline; Phosphodiesterase Inhibitors; Portal Pressure; Protective Agents; Rats; Tumor Necrosis Factor-alpha

Inflammation and oxidative stress are the key events in carcinogenetic transformation. Black raspberries (BRB) have been demonstrated to have antioxidant, antiinflammatory and anticancer bioactivities. In this study, a concanavalin A induced hepatitis mouse model is used to examine the effect of BRB extract on hepatic injury. Three BRB extracts, including ethanol/H2O extracts (both anthocyanin-contained fraction and nonanthocyanin-contained fraction) and hexane extract were used. The alterations in hepatic histology, apoptosis, and oxidative stress were observed in the animals pretreated with BRB extracts and then challenged by concanavalin A. Results indicate that ethanol/H2O extracts can inhibit Con A induced liver injury. The hepatic protection by the ethanol/H2O BRB extracts is associated with decreases of lipid peroxidation and NDA oxidative damage. Importantly, the BRB extracts increase manganese superoxide dismutase (MnSOD) activity but not the CuZnSOD. The preservation of MnSOD by BRB extracts is associated with the protective action in the liver challenged by Con A. Ethanol/H2O BRB extracts function as antioxidants, thus demonstrating the critical role of oxidative stress in the Con A induced liver injury, and providing evidence that the protective effects of ethanol/H2O BRB extracts result, at least in part, from their antioxidant action.

Topics: Animals; Antioxidants; Catalase; Cell Death; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Ethanol; Glutathione; Hepatocytes; In Situ Nick-End Labeling; Lipid Peroxidation; Liver; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Plant Extracts; Rosaceae; Superoxide Dismutase

Adult worm extract from Ascaris suum (Asc) has immunosuppressive activity and elicits Th2/IL-4/IL-10 response. This study evaluated the prophylactic and therapeutic effect of Asc in a murine model of concanavalin A (ConA)-induced autoimmune hepatitis (AIH). BALB/c mice received ConA, iv, (20 mg/kg), and three groups of animals were formed: (1) AIH, received only ConA; (2) AIH + Asc prophylactic, treated with Asc (1 mg/ml), ip, 30 min before of the AIH; and (3) AIH + Asc therapeutic, treated with Asc 2 h after the AIH. Plasma transaminase and immunoglobulins (measured at 8 and 24 h and 7 days after treatment) and cytokine production (IL-4, IL-10, IL-13, and IFN-γ) by splenocytes upon ConA and Asc stimulus were compared. The livers were weighed and examined histologically. In the AIH group, there was an increase in liver weight, transaminase levels, and total immunoglobulins. These parameters were reduced by 8-24 h and 7 days in the prophylactic group, but in the therapeutic group, only on day 7. The survival rate of mice in the AIH group was 38.5%, compared to 67% in the therapeutic Asc group. The survival rate of the animals with AIH that were prophylactically treated with Asc was 100%. A decrease of cellular infiltration and high levels of IL-4, IL-10, and IL-13 were induced by Asc. An increase of liver fibrosis was also observed, but with less intensity with prophylactic treatment. Thus, the Ascaris components have an inhibitory effect on AIH, with an intense Th2 immune response.

Topics: Animals; Antigens, Helminth; Ascariasis; Ascaris suum; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Autoimmune; Immunomodulation; Interleukin-10; Interleukin-13; Interleukin-4; Mice; Mice, Inbred BALB C

Acute liver failure, the fatal deterioration of liver function, is the most common indication for emergency liver transplantation, and drug-induced liver injury and viral hepatitis are frequent in young adults. Stem cell therapy has come into the limelight as a potential therapeutic approach for various diseases, including liver failure and cirrhosis. In this study, we investigated therapeutic effects of tonsil-derived mesenchymal stem cells (T-MSCs) in concanavalin A (ConA)- and acetaminophen-induced acute liver injury. ConA-induced hepatitis resembles viral and immune-mediated hepatic injury, and acetaminophen overdose is the most frequent cause of acute liver failure in the United States and Europe. Intravenous administration of T-MSCs significantly reduced ConA-induced hepatic toxicity, but not acetaminophen-induced liver injury, affirming the immunoregulatory capacity of T-MSCs. T-MSCs were successfully recruited to damaged liver and suppressed inflammatory cytokine secretion. T-MSCs expressed high levels of galectin-1 and -3, and galectin-1 knockdown which partially diminished interleukin-2 and tumor necrosis factor α secretion from cultured T-cells. Galectin-1 knockdown in T-MSCs also reversed the protective effect of T-MSCs on ConA-induced hepatitis. These results suggest that galectin-1 plays an important role in immunoregulation of T-MSCs, which contributes to their protective effect in immune-mediated hepatitis. Further, suppression of T-cell activation by frozen and thawed T-MSCs implies great potential of T-MSC banking for clinical utilization in immune-mediated disease.

Topics: Adult; Animals; Blotting, Western; Cell Proliferation; Cell- and Tissue-Based Therapy; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Galectin 1; Hepatocytes; Humans; Immunoenzyme Techniques; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mitogens; Palatine Tonsil; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; T-Lymphocytes

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)-induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA-mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)-depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.

Topics: Adoptive Transfer; Animals; Blotting, Western; Bone Marrow Cells; CD11b Antigen; Cell Movement; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Dexamethasone; Flow Cytometry; Glucocorticoids; Liver; Male; Mice, Inbred C57BL; Mitogens; Myeloid Cells; Receptors, Chemokine; Spleen; T-Lymphocytes; T-Lymphocytes, Regulatory

The present study was designed to investigate the potential benefits of vitamin C (VC) in treating immunological liver injury induced by Concanavalin A (Con A, 20 mg kg(-1)) in mice. Interestingly, VC administration significantly reduced serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total-bilirubin (T-bilirubin) in Con A-lesioned mice, while serum concentrations of albumin and total-protein (T-protein) were increased. Moreover, inflammatory cytokine profiles, such as interferon-gamma (IFN-γ), interleukin-4 (IL-4), interleukin-6 (IL-6) and interleukin-8 (IL-8), were decreased in liver tissue by VC administration. Morphological examination showed that Con A-induced liver damage was effectively mitigated. As shown in RT-PCR assay, VC administration resulted in down-regulated mRNA expressions of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In addition, VC contributed towards the reduction of intrahepatic tumor necrosis factor alpha (TNF-α) and the receptor (TNF-R) protein levels, as well as decreasing IKKβ, p-IκBα, p50 and NF-κB expressions; furthermore, VC blocked intranuclear DNA-binding NF-κB locus. Our findings show that VC effectively attenuates Con A-mediated immunotoxicity in liver tissue, through an underlying mechanism which relates to dampening of the intrahepatic NF-κB signal pathway, thereby reducing cytotoxicity within hepatocytes.

Topics: Animals; Ascorbic Acid; Chemical and Drug Induced Liver Injury; Concanavalin A; Humans; Liver; Male; Mice; NF-kappa B; Receptors, Tumor Necrosis Factor; Signal Transduction

Fulminant hepatitis is a severe liver disease characterized by massive hepatocyte necrosis and clinical signs of liver failure. This study explores the expression profile of microRNAs, which are regulators of a number of pathophysiological processes, during the early stage of concanavalin A (Con A)-induced hepatitis.. Balb/c mice were given ConA injections to induce fulminant hepatitis. miRNA expression profiling in liver tissues was carried out by microarray analysis. The differentially expressed miRNAs were subjected to time sequence profile analysis, gene-miRNA regulatory network analysis, and gene ontology-miRNA regulatory network analysis.. Eleven miRNAs among multiClass were found to be significantly differentially expressed between liver tissue in early stage fulminant hepatitis and normal control liver tissue. Mmu-miR-133a was the most differentially expressed with the strongest regulatory ability, regulating 47 mRNAs. Mmu-miR-10a was the most highly expressed in the microRNA-GO-Network and also exerted a strong regulatory ability. The expression profiles of miR-133a and miR-10a were verified by RT-PCR.. These results show that, in the early stage, ConA-induced fulminant hepatitis induces a distinct miRNA expression profile. This differential miRNA expression profile may provide pathogenic clues and potential diagnostic and prognostic markers in acute and severe liver disease.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Bilirubin; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Ontology; Gene Regulatory Networks; L-Lactate Dehydrogenase; Liver; Male; Mice, Inbred BALB C; MicroRNAs; Models, Genetic; Oligonucleotide Array Sequence Analysis; Reverse Transcriptase Polymerase Chain Reaction; Transcriptome

Fruiting bodies of Taiwanofungus camphoratus have been widely used as an antidote for food poisoning and considered to be a precious folk medicine for anti-inflammation and hepatoprotection. Zhankuic acid A (ZAA) is its major pharmacologically active compound. Janus kinase 2 (JAK2), whose activation is involved in cytokine signaling, plays critical roles in the development and biology of the hematopoietic system. JAK2 has been implicated as a therapeutic target in inflammatory diseases. The HotLig modeling approach was used to generate the binding model for ZAA with JAK2, showing that ZAA could bind to the ATP-binding pocket of JAK2 exclusively via the H-bond. The interaction between ZAA and JAK2 was verified by antibody competition assay. Binding of ZAA to JAK2 reduced antibody recognition of native JAK2. The expressions of phosphorylated JAK2 and STATs were analyzed by immuno-blotting. ZAA reduced the phosphorylation and downstream signaling of JAK2, and inhibited the interferon (IFN)-γ/signal transducer and activator of transcription (STAT) 1/interferon regulatory factor (IRF)-1 pathway. The protective effect of ZAA on liver injury was evaluated in mice by Con-A-induced acute hepatitis. Pre-treatment with ZAA also significantly ameliorated acute liver injury in mice. Therefore, ZAA can inhibit JAK2 phosphorylation and protect against liver injury during acute hepatitis in mice. In this study, we present data that ZAA exerts anti-inflammatory effects through the JAK2 signaling pathway. As such, ZAA may be a potential therapeutic agent for the treatment of inflammatory diseases.

Topics: Animals; Apoptosis; Cell Line; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Ergosterol; Gene Expression; Humans; Janus Kinase 2; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mitogens; Molecular Structure; Spleen; T-Lymphocytes

T cell-mediated immune responses contribute to the hepatocellular injury during autoimmune hepatitis, viral infection, and hepatotoxins. Pharmacological compounds regulating immune responses are suitable candidates for prevention/treatment of this pathology. Therefore, the main aim of this study was to define the effects of antioxidant, anti-inflammatory mixture of citrus peel extract (CPE) on the immune-mediated liver injury.. The influence of CPE on liver injury was determined by the activity of transaminases in plasma and the histological changes. Anti-inflammatory and antioxidant effects were studied by measuring frequency of T regulatory cells (Tregs), cytokines (TNF-α, IL-10, and IFN-γ), and nitric oxide levels.. The CPE application notably prevents development of liver injury through decreasing levels of both cytokines (TNF-alpha, INF) and regulatory T cells and increasing levels of IL-10. CPE injection also diminished the serum NO, which in turn resulted in evident reduction of the liver damage.. Our findings represent the primary preclinical data indicating that the CPE in vivo could ameliorate Con A induced hepatitis. The low dose of CPE most likely can be used for the treatment of the T cell-mediated liver injury as in autoimmune hepatitis, alcoholic hepatitis, and chronic viral hepatitis.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Citrus; Concanavalin A; Hepatitis; Interferon-gamma; Interleukin-10; Mice; Nitric Oxide; Plant Extracts; Spleen; T-Lymphocytes, Regulatory; Transaminases; Tumor Necrosis Factor-alpha

Chronic hepatitis is a major cause of liver cancer, so earlier treatment of hepatitis might be reducing liver cancer incidence. Hepatitis can be induced in mice by treatment with Concanavalin A (Con A); the resulting liver injury causes significant CD4(+) T cell activation and infiltration. In these T cells, Roquin, a ring-type E3 ubiquitin ligase, is activated. To investigate the role of Roquin, we examined Con A-induced liver injury and T cell infiltration in transgenic (Tg) mice overexpressing Roquin specifically in T cells. In Roquin Tg mice, Con A treatment caused greater increases in both the levels of liver injury enzymes and liver tissue apoptosis, as revealed by TUNEL and H&E staining, than wild type (WT) mice. Further, Roquin Tg mice respond to Con A treatment with greater increases in the T cell population, particularly Th17 cells, though Treg cell counts are lower. Roquin overexpression also enhances increases in pro-inflammatory cytokines, including IFN-γ, TNF-α and IL-6, upon liver injury. Furthermore, Roquin regulates the immune response and apoptosis in Con A induced hepatitis via STATs, Bax and Bcl2. These findings suggest that over-expression of Roquin exacerbates T-cell mediated hepatitis.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Gene Expression Regulation; Hepatocytes; Interferon-gamma; Interleukin-6; Lymphocyte Activation; Lymphocyte Count; Mice; Mice, Transgenic; Promoter Regions, Genetic; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; STAT Transcription Factors; T-Lymphocytes, Regulatory; Th17 Cells; Tumor Necrosis Factor-alpha; Ubiquitin-Protein Ligases

The purpose of the present study is to explore the protective effects of sodium butyrate (SB) pretreatment on concanavalin A (Con A)-induced acute liver injury in mice. The model animals were first administered intraperitoneally with SB. Half an hour later, acute liver injury mouse model was established by caudal vein injection with Con A (15 mg/kg). Then, levels of serous alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using standard clinical method by an automated chemistry analyzer, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were measured by ELISA, and pathological changes in hepatic tissue were observed by using HE staining and light microscopy. The expression and release of high-mobility group box 1 (HMGB1) were assessed by using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry and ELISA. The results showed that the pretreatment of SB significantly protected Con A-treated mice from liver injury as evidenced by the decrease of serum ALT, AST (P < 0.01) and reduction of hepatic tissues necrosis. SB also decreased levels of serous TNF-α and IFN-γ (P < 0.01). Furthermore, the expression and release of HMGB1 were markedly inhibited by SB pretreatment (P < 0.05 or P < 0.01). These results suggest that the attenuating effect of SB on Con A-induced acute liver injury may be due to its role of reducing the TNF-α and IFN-γ production, and inhibiting HMGB1 expression and release.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Butyric Acid; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; HMGB1 Protein; Interferon-gamma; Liver; Mice; Tumor Necrosis Factor-alpha

Chronic inflammation is strongly associated with an increased risk for hepatocellular carcinoma (HCC) development. The multidrug resistance 2 (Mdr2)-knockout (KO) mouse (adenosine triphosphate-binding cassette b4(-/-) ), a model of inflammation-mediated HCC, develops chronic cholestatic hepatitis at an early age and HCC at an adult age. To delineate factors contributing to hepatocarcinogenesis, we compared the severity of early chronic hepatitis and late HCC development in two Mdr2-KO strains: Friend virus B-type/N (FVB) and C57 black 6 (B6). We demonstrated that hepatocarcinogenesis was significantly less efficient in the Mdr2-KO/B6 mice versus the Mdr2-KO/FVB mice; this difference was more prominent in males. Chronic hepatitis in the Mdr2-KO/B6 males was more severe at 1 month of age but was less severe at 3 months of age in comparison with age-matched Mdr2-KO/FVB males. A comparative genome-scale gene expression analysis of male livers of both strains at 3 months of age revealed both common and strain-specific aberrantly expressed genes, including genes associated with the regulation of inflammation, the response to oxidative stress, and lipid metabolism. One of these regulators, galectin-1 (Gal-1), possesses both anti-inflammatory and protumorigenic activities. To study its regulatory role in the liver, we transferred the Gal-1-KO mutation (lectin galactoside-binding soluble 1(-/-) ) from the B6 strain to the FVB strain, and we demonstrated that endogenous Gal-1 protected the liver against concanavalin A-induced hepatitis with the B6 genetic background but not the FVB genetic background.. Decreased chronic hepatitis in Mdr2-KO/B6 mice at the age of 3 months correlated with a significant retardation of liver tumor development in this strain versus the Mdr2-KO/FVB strain. We found candidate factors that may determine strain-specific differences in the course of chronic hepatitis and HCC development in the Mdr2-KO model, including inefficient anti-inflammatory activity of the endogenous lectin Gal-1 in the FVB strain.

Topics: Animals; ATP Binding Cassette Transporter, Subfamily B; ATP-Binding Cassette Sub-Family B Member 4; Carcinoma, Hepatocellular; Cell Transformation, Neoplastic; Chemical and Drug Induced Liver Injury; Concanavalin A; Galectin 1; Hepatitis, Chronic; Liver; Liver Neoplasms; Male; Methionine Adenosyltransferase; Mice; Mice, Inbred Strains; Mice, Knockout

Exposure of mice to perfluorooctanoate (PFOA) evokes pronounced hepatomegaly along with significant alterations in both the histological structure and immune status of the liver. The present study was designed to evaluate the effects of this perfluorochemical on immune-mediated liver damage. In this connection, the influence of both sub-acute (10 days), moderate-dose (0.002% w/w=3±0.7mg/kg body weight/day) and short-term (28 days), low-dose (0.00005% w/w=70±2μg/kg body weight/day) dietary pretreatment with PFOA on the development of concanavalin A (Con A)-induced liver damage in mice was examined. With sub-acute, moderate, but not short-term, low-dose exposure, PFOA aggravated the acute liver damage caused by Con A, i.e., elevated serum levels of transaminases and led to more pronounced damage of hepatic tissue. This aggravation was associated with significantly enhanced hepatic level of interleukin-6 (IL-6), but unaltered hepatic levels of tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ) and interleukin-4 (IL-4). Moreover, hepatic DNA fragmentation was not changed by sub-acute exposure to the moderate-dose. Our findings imply that exposure to PFOA may sensitize hepatic parenchymal cells to other toxicants that activate the hepatic immune system and thereby aggravate liver injury during acute inflammation.

Topics: Administration, Oral; Animals; Caprylates; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; DNA Fragmentation; Dose-Response Relationship, Drug; Drug Synergism; Fluorocarbons; Liver; Male; Mice; Mice, Inbred C57BL; Time Factors; Transaminases

Concanavalin A (ConA)-induced hepatitis is an experimental murine model mirroring the pathology of human autoimmune hepatitis.. To investigate the effects of intrasplenically transplanted fetal hepatocytes (BNL.CL2) transfected with recombinant adenovirus vector expressing the IL-18 binding protein (IL-18BP) and IL-4 fusion protein on ConA-induced hepatitis in mice.. Ad-IL-18BP/IL-4 was used to infect BNL.CL2 cells. IL-4 and IL-18BP fusion protein expression were detected by ELISA and Western blotting. BNL.CL2 cells infected with Ad-IL-18BP/IL-4 were intrasplenically transplanted into mice. After 10 days, mice were injected with ConA (15 mg/kg), and sacrificed 18 hours later. Liver injury was assessed by serum transaminase and liver histology. TNF-α, IL-18, IL-4, IL-10, IL-12p70 and monocyte-chemoattracting protein (MCP)-1 levels in serum and liver homogenates were detected by ELISA. Signaling molecules in liver homogenates were analyzed by Western blotting.. Ad-IL-18BP/IL-4 effectively expressed the IL-18BP/IL-4 fusion protein for more than 14 days in BNL.CL12 cells. Treatment of mice with Ad-IL-18BP/IL-4-BNL.CL2 before ConA injection significantly reduced the elevated plasma levels of transaminases compared with ConA control groups. TNF-α, IL-18, IL-12p70 and MCP-1 levels in serum and liver homogenates from mice transplanted with Ad-IL-18BP/IL-4-BNL.CL2 were lower and IL-4 and IL-10 levels were higher than control groups. Phosphorylation levels of NF-κB p65, AKT, p38 and JNK1/2 in liver homogenates were markedly suppressed by Ad-IL-18BP/IL-4.. Ad-IL-18BP/IL-4 was effectively transfected into mouse BNL.CL2 cells. Intrasplenic transplantation of Ad-IL-18BP/IL-4-BNL.CL12 cells alleviated the severity of inflammation in ConA-induced experimental hepatitis and provides a useful basis for the targeted gene therapy of liver disease.

Topics: Adenoviridae; Animals; Cell Line; Cell Transplantation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Fetus; Hepatitis; Hepatocytes; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-4; Male; Mice; Mice, Inbred BALB C; Spleen

Fulminant hepatitis (FH) is a disease characterized by massive destruction of hepatocytes with severe impairment of liver function. The pathogenesis of FH is not fully understood, but hyperactivity of T cells and macrophages with excessive production of cytokines are important hallmarks of the condition. In this study, we investigated the role of interleukin (IL)-25 in FH. IL-25 expression was evaluated in patients with FH and in livers of mice with FH induced by D-galactosamine (D-Gal) and lipopolysaccharide (LPS). Mice were treated with IL-25 before D-Gal/LPS-induced FH and before or after concanavalin A (ConA)-induced FH. Mononuclear cells were isolated from livers of mice treated with or without IL-25 and analyzed for GR1(+) CD11b(+) cells. CFSE-labeled T cells were cocultured with GR1(+) CD11b(+) cells and their proliferation was evaluated by flow cytometry. Mice were also treated with a depleting anti-GR1 antibody before IL-25 and D-Gal/LPS administration. IL-25 was constitutively expressed in mouse and human liver and down-regulated during FH. IL-25 prevented D-Gal/LPS-induced FH and this effect was associated with increased infiltration of the liver with cells coexpressing GR1 and CD11b. In vitro studies showed that GR1(+) CD11b(+) cells isolated from mice given IL-25 inhibited T-cell proliferation. Consistently, in vivo depletion of GR1(+) cells abrogated the protective effect of IL-25 in experimental D-Gal/LPS-induced FH. IL-25 was both preventive and therapeutic in ConA-induced FH.. IL-25 expression is markedly reduced during human and experimental FH. IL-25 promotes liver accumulation of GR1(+) CD11b(+) cells with immunoregulatory properties.

Topics: Animals; CD11b Antigen; Cell Proliferation; Chemical and Drug Induced Liver Injury; Coculture Techniques; Concanavalin A; Disease Models, Animal; Down-Regulation; Galactosamine; Hepatitis; Hepatocytes; Humans; Interleukin-17; Interleukins; Lipopolysaccharides; Male; Mice; Mice, Inbred BALB C; Myeloid Cells; Receptors, Chemokine; T-Lymphocytes

Several recent studies have demonstrated that phospholipids (PLs) supplementation can modulate the function of cultured-immune cells. Furthermore, dietary PLs have been shown to ameliorate inflammatory processes and immune responses in arthritic and diabetic murine models, respectively. Thus, the aim of this study was to examine the immune-modulating activities of dietary soybean PLs in mice, with particular emphasis on the immune cell functions.. Mice were fed semisynthetic diets for 6 weeks, which contained either 7% soybean oil or 5% soybean oil plus 2% of either PL: phosphatidylcholine (PC), phosphatidylinositol (PI), or phosphatidylserine (PS). Production of concanavalin A (Con A)-induced proinflammatory cytokines was significantly decreased in the splenocytes isolated from mice fed PI compared to other lipids. Supplementation of the diet with PI, but not with the other lipids, significantly suppressed the proinflammatory cytokine serum levels and the development of Con A-induced liver damages.. These observations suggest that dietary PI influenced immune functions, resulting in the prevention of pathogenesis and development of the liver injury in mice.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Diet; Liver; Male; Mice; Mice, Inbred C57BL; Phosphatidylcholines; Phosphatidylinositols; Phosphatidylserines; Soybean Oil

The effect of ginsenoside Rg1 (Rg1) on hepatic damage caused by concanavalin A (Con A) has not been fully elucidated. This study was designed to evaluate the protective effect of Rg1 on Con A-induced hepatitis in mice and explore the potential mechanisms of this effect. C57BL/6 mice were divided randomly into the following four experimental groups: phosphate-buffered saline group, Rg1 group, Con A group, Con A + Rg1 group. Mice received Rg1 (20 mg/kg) 3 h before intravenous administration of Con A (15 mg/kg). Levels of alanine transaminase, aspartate transaminase and cytokine production were measured, the amount of phosphorylated IκBα and p65 were tested, the numbers of CD4(+) and CD8(+) T lymphocytes infiltrated in the blood, spleen and liver were calculated, intercellular adhesion molecule-1 (ICAM-1) and interferon-inducible chemokine-10 (CXCL-10) levels were measured and histological examination of the livers was conducted. Pretreatment with Rg1 markedly reduced the elevated levels of serum aminotransferase, ameliorated liver damage and suppressed proinflammatory cytokines secretion via inhibition NF-κB activity following Con A injection of mice. Furthermore, Rg1 administration reduced ICAM-1 and CXCL-10 mRNA expression in the liver as well as the number of CD4(+) and CD8(+) T lymphocytes infiltrating in the liver. Rg1 reduced the incidence of liver damage through inhibition of the proinflammatory response and suppressed the recruitment of CD4(+) and CD8(+) T lymphocytes to the liver. These data indicate that Rg1 represents a novel agent for the treatment of T lymphocyte-dependent liver injury.

Topics: Animals; Blotting, Western; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Central Nervous System Agents; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Concanavalin A; Cytokines; Drugs, Chinese Herbal; Gene Expression; Ginsenosides; I-kappa B Proteins; Intercellular Adhesion Molecule-1; Liver; Male; Mice; Mice, Inbred C57BL; NF-kappa B; NF-KappaB Inhibitor alpha; Phosphorylation; Reverse Transcriptase Polymerase Chain Reaction; Transcription Factor RelA

Hepatitis induced by concanavalin A (Con A) in mice is well known to be a T-lymphocyte-mediated injury. It has been reported that T helper (Th)1 and Th2 lymphocytes use α4 integrin and vascular adhesion protein (VAP)-1, respectively, to adhere within the hepatic sinusoids. Therefore, we investigated whether inhibition of these molecules ameliorates or worsens the Con A-induced hepatic injury in vivo. Vehicle or antibody to α4 integrin or VAP-1 was intravenously administered 30 minutes before Con A administration. In control mice Con A markedly increased the serum alanine aminotransferase (ALT) level in a dose-dependent manner, and induced a massive infiltration of CD3, particularly interleukin (IL)-4 producing CD4 T cells and liver injury. Both parameters were reduced by anti-VAP-1 antibody despite antibody only blocking the adhesion, not the amine oxidase activity of VAP-1. Both activities of VAP-1 were eliminated in VAP-1-deficient mice and both Con A-induced liver injury and CD4 T-cell infiltration were eradicated. In contrast to anti-VAP-1, anti-α4 integrin antibody reduced interferon-gamma (IFN-γ)-producing CD3 T cells but this worsened Con A hepatitis, suggesting inhibition of a suppressor cell. Con A induced the recruitment of CD49d(+) monocytic myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) into the liver. Anti-α4 integrin dramatically blocked the influx of MDSCs but not Tregs.. Our findings show that VAP-1 and α4 integrin have opposing effects in Con A-induced hepatic injury, which is associated with blocking the recruitment of CD4 lymphocytes and monocytic MDSCs, respectively. Moreover, these data provide the rationale for a potential therapeutic approach to target adhesion molecules in autoimmune hepatitis.

Topics: Alanine Transaminase; Amine Oxidase (Copper-Containing); Animals; Antibodies, Anti-Idiotypic; CD4-Positive T-Lymphocytes; Cell Adhesion Molecules; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Integrin alpha4; Liver; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; T-Lymphocytes, Regulatory; Treatment Outcome

Coronin 1, a member of the evolutionary conserved coronin protein family, is highly expressed in all leukocytes. In mice and human, genetic inactivation of coronin 1 results in immuno-deficiencies that are linked to a strong reduction of naïve T cell numbers in peripheral organs, while memory/effector T cells, B cells, monocytes and neutrophils are less or not at all affected. Whether or not coronin 1 is important for leukocyte functions such as migration and phagocytosis has been a matter of debate. The current work addresses coronin 1-dependent leukocyte function by analyzing the response of coronin 1-deficient mice in a model of concanavalin A (Con A)-induced liver injury. Histological evaluation and determination of serum liver enzyme levels showed that coronin 1-deficient mice develop signs of acute hepatitis similar to Con A-treated wild type mice despite a reduced activation of T cells in the absence of coronin 1. Furthermore, analysis by intravital microscopy following Con A stimulation revealed that Gr-1+ neutrophils and CD4+ T cell adhesion in the post-sinusoidal venules increased in wild type as well as in coronin 1-deficient mice. These results suggest that coronin 1, while important for naïve T cell survival, is dispensable for other leukocyte function under inflammatory conditions in vivo.

Topics: Animals; B-Lymphocytes; CD4-Positive T-Lymphocytes; Cell Adhesion; Cell Movement; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis; Inflammation; Leukocytes; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Microfilament Proteins; Neutrophils

Immunization with high-dose heat shock protein gp96, an endoplasmic reticulum counterpart of the Hsp90 family, significantly enhances regulatory T cell (Treg) frequency and suppressive function. Here, we examined the potential role and mechanism of gp96 in regulating immune-mediated hepatic injury in mice. High-dose gp96 immunization elicited rapid and long-lasting protection of mice against concanavalin A (Con A)-and anti-CD137-induced liver injury, as evidenced by decreased alanine aminotransaminase (ALT) levels, hepatic necrosis, serum pro-inflammatory cytokines (IFN-γ, TNF-α, and IL-6), and number of IFN-γ (+) CD4(+) and IFN-γ (+) CD8(+) T cells in the spleen and liver. In contrast, CD4(+)CD25(+)Foxp3(+) Treg frequency and suppressive function were both increased, and the protective effect of gp96 could be generated by adoptive transfer of Treg cells from gp96-immunized mice. In vitro co-culture experiments demonstrated that gp96 stimulation enhanced Treg proliferation and suppressive function, and up-regulation of Foxp3, IL-10, and TGF-β1 induced by gp96 was dependent on TLR2- and TLR4-mediated NF-κB activation. Our work shows that activation of Tregs by high-dose gp96 immunization protects against Con A- and anti-CD137-induced T cell-hepatitis and provides therapeutic potential for the development of a gp96-based anti-immune hyperactivation vaccine against immune-mediated liver destruction.

Topics: Adoptive Transfer; Alanine Transaminase; Animals; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Gene Expression Regulation; Immunization; Liver; Lymphocyte Activation; Membrane Glycoproteins; Mice; Spleen; T-Lymphocytes, Regulatory

An increasing number of studies have suggested that phosphoinositide 3-kinase-γ (PI3Kγ) and PI3Kδ are involved in the pathogenesis of autoimmune and inflammatory diseases, such as asthma and atherosclerosis. However, the underlying mechanism of acute hepatitis remains unknown. The present study aimed to determine the effect of PI3Kδ/γ inhibition on hepatic injury in a murine model of hepatitis induced by concanavalin A (ConA). It was demonstrated that the pharmacological inhibition of PI3Kδ/γ by TG100-115 did not prevent liver damage following ConA challenge. Furthermore, the PI3Kδ/γ inhibition resulted in elevated transaminase activity in the serum, aggravated hepatic lesions characterized by hepatic necrosis, increased inflammatory cell infiltration and apoptosis of hepatocytes. Survival tests demonstrated that TG100-115 significantly increased the death rate of mice following ConA challenge. In addition, TG100-115 increased the serum levels of the proinflammatory cytokine IL-2 following ConA injection. These results may oppose the development of PI3Kδ/γ inhibitors as therapeutic agents, particularly for the treatment of human hepatitis.

Topics: Animals; Apoptosis; Cell Proliferation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Class I Phosphatidylinositol 3-Kinases; Class Ib Phosphatidylinositol 3-Kinase; Concanavalin A; Cytokines; Female; Hepatitis; Hepatocytes; Humans; Immunoenzyme Techniques; Inflammation; Mice; Mice, Inbred BALB C; Mitogens; Phenols; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Pteridines

For many liver diseases, including viral and autoimmune hepatitis, immune cells play an important role in the development and progression of liver injury. Concanavalin A (Con A) administration to rodents has been used as a model of immune-mediated liver injury resembling human autoimmune hepatitis. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been demonstrated to alter the development of immune-mediated diseases. Mice pretreated with TCDD developed exacerbated liver injury in response to administration of a mild dose (6 mg/kg) of Con A. In the present study, we tested the hypothesis that TCDD pretreatment exacerbates Con A-induced liver injury by enhancing the activation and recruitment of accessory cell types including neutrophils, macrophages, and natural killer (NK) cells. Mice were treated with 0, 0.3, 3, or 30 μg/kg TCDD and 4 days later with Con A or saline. TCDD pretreatment with doses of 3 and 30 μg/kg significantly increased liver injury from Con A administration. The plasma concentrations of neutrophil chemokines were significantly increased in TCDD-pretreated mice after Con A administration. NKT cell-deficient (CD1d KO) mice were used to examine whether NKT cells were required for TCDD/Con A-induced liver injury. CD1d KO mice were completely protected from liver injury induced by treatment with Con A alone, whereas the injury from TCDD/Con A treatment was reduced but not eliminated. However, T-cell deficient (RAG1 KO) mice were protected from liver injury induced by Con A irrespective of pretreatment with TCDD. TCDD/Con A treatment increased the percentage of NK cells expressing the activation marker CD69. Depletion of NK cells prior to treatment resulted in significant reductions in plasma interferon-γ and liver injury from TCDD/Con A treatment. In summary, exposure to TCDD exacerbated the immune-mediated liver injury induced by Con A, and our findings suggest that NK cells play a critical role in this response.

Topics: Animals; Antigens, CD; Antigens, CD1d; Antigens, Differentiation, T-Lymphocyte; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Dose-Response Relationship, Drug; Homeodomain Proteins; Inflammation Mediators; Lectins, C-Type; Liver; Lymphocyte Activation; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Neutrophil Infiltration; Polychlorinated Dibenzodioxins; Time Factors

Salvianolic acid A (SalA) is a phenolic carboxylic acid derivative extracted from Salvia miltiorrhiza. It has many biological and pharmaceutical activities. The purpose of this study was to investigate the effect of SalA on concanavalin A (ConA)-induced acute hepatic injury in Kunming mice and to explore the role of SIRT1 in such an effect. The results showed that in vivo pretreatment with SalA significantly reduced ConA-induced elevation in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and decreased levels of the hepatotoxic cytokines such as interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Moreover, the SalA pretreatment ameliorated the increases in NF-κB and in cleaved caspase-3 caused by ConA exposure. Whereas, the pretreatment completely reversed expression of the B-cell lymphoma-extra large (Bcl-xL). More importantly, the SalA pretreatment significantly increased the expression of SIRT1, a NAD(+)-dependent deacetylase, which was known to attenuate acute hypoxia damage and metabolic liver diseases. In our study, the increase in SIRT1 was closely associated with down-regulation of the p66 isoform (p66shc) of growth factor adapter Shc at both protein and mRNA levels. In HepG2 cell culture, SalA pretreatment increased SIRT1 expression in a time and dose-dependent manner and such an increase was abrogated by siRNA knockdown of SIRT1. Additionally, inhibition of SIRT1 significantly reversed the decreased expression of p66shc, and attenuated SalA-induced p66shc down-regulation. Collectively, the present study indicated that SalA may be a potent activator of SIRT and that SalA can alleviate ConA-induced hepatitis through SIRT1-mediated repression of the p66shc pathway.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; bcl-X Protein; Caffeic Acids; Caspase 3; Chemical and Drug Induced Liver Injury; Concanavalin A; Down-Regulation; Epigenetic Repression; Hep G2 Cells; Hepatitis; Humans; Interferon-gamma; Lactates; Liver; Male; Mice; NF-kappa B; RNA, Messenger; RNA, Small Interfering; Shc Signaling Adaptor Proteins; Sirtuin 1; Src Homology 2 Domain-Containing, Transforming Protein 1; Tumor Necrosis Factor-alpha

Necrostatin-1 (Nec-1) inhibits receptor-interacting protein 1 (RIP1) kinase and programmed necrosis. This study was designed to examine the protective effects and mechanisms of Nec-1 in concanavalin A- (ConA-) induced hepatitis in mice.. C57BL/6 mice were exposed to ConA via tail vein injection and injected intraperitoneally with Nec-1 or vehicle. Levels of serum liver enzymes and histopathology were determined. Levels of inflammatory cytokines with ConA-induced hepatitis were determined with real-time polymerase chain reaction (real-time PCR). The expression of TNF- α , RIP1, and LC3 was detected with immunohistochemical staining. The expression of TNF- α , IFN- γ , IL2, IL6, caspase 3, RIP1, beclin-1, and LC3 protein was assessed by immunofluorescence and western blotting. Autophagosomes were observed with transmission electron microscopy (TEM).. Amelioration in liver functions and histopathological changes and the suppression of inflammatory cytokine production were observed in Nec-1-injected mice. Western blotting analysis showed that the expression of TNF- α , IFN- γ , IL2, IL6, and RIP1 was significantly reduced in the Nec-1-injected mice, which was confirmed by immunofluorescence and immunohistochemistry. Autophagosome formation was significantly reduced by Nec-1 treatment, as the expression of beclin-1 and LC3, determined with immunofluorescence and western blotting.. These results demonstrate that Nec-1 prevents ConA-induced liver injury via RIP1-related and autophagy-related pathways.

Topics: Animals; Autophagy; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation; GTPase-Activating Proteins; Imidazoles; Indoles; Liver; Liver Failure, Acute; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Microtubule-Associated Proteins; Necrosis; Phagosomes; Real-Time Polymerase Chain Reaction; Transaminases; Tumor Necrosis Factor-alpha

Understanding the molecular pathogenesis of inflammatory liver disease is essential to design efficient therapeutic approaches. In hepatocytes, the dimeric transcription factor c-JUN/AP-1 is a major mediator of cell survival during hepatitis, although functions for other JUN proteins in liver disease are less defined. Here, we found that JUNB was specifically expressed in human and murine immune cells during acute liver injury. We analyzed the molecular function of JUNB in experimental models of hepatitis, including administration of concanavalin A (ConA) or α-galactosyl-ceramide, which induce liver inflammation and injury. Mice specifically lacking JUNB in hepatocytes displayed a mild increase in ConA-induced liver damage. However, targeted deletion of Junb in immune cells and hepatocytes protected against hepatitis in experimental models that involved NK/NKT cells. The absence of JUNB in immune cells decreased IFN-γ expression and secretion from NK and NKT cells, leading to reduced STAT1 pathway activation. Systemic IFN-γ treatment or adenovirus-based IRF1 delivery to Junb-deficient mice restored hepatotoxicity, and we demonstrate that Ifng is a direct transcriptional target of JUNB. These findings demonstrate that JUNB/AP-1 promotes cell death during acute hepatitis by regulating IFN-γ production in NK and NKT cells and thus functionally antagonizes the hepatoprotective function of c-JUN/AP-1 in hepatocytes.

Topics: Animals; Cell Death; Chemical and Drug Induced Liver Injury; Concanavalin A; Galactosylceramides; Hepatitis; Hepatocytes; Humans; Interferon Regulatory Factor-1; Interferon-gamma; Killer Cells, Natural; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Poly I-C; Recombinant Fusion Proteins; STAT1 Transcription Factor; Transcription Factors; Transcription, Genetic; Transduction, Genetic

To explore the effect of Ronggan Mixture (RM) on immunoregulation and hepatocyte apoptosis-related factors in concanavalin A (Con A) induced acute immunological liver injury mice.. Totally 60 hepatitis B virus (HBV) transgenic mice were randomly divided into 6 groups, i.e., the blank control group, the model group, the RM group, the Herba Artemisiae Scopariae (HAS) group, the Yinchenhao Decoction (YD) group, and the Bifendate group, 10 mice in each group. The acute immunological liver injury model was established by tail vein injection of ConA. Fourteen days before modeling, normal saline was administered to mice in the blank control group and the model group. RM, YD, HAS decoction, and Bifendate solution was respectively given to mice in the RM group, the YD group, the HAS group, and the Bifendate group. The medication was performed once daily. One h after the last gastrogavage, phosphate buffer solution (PBS) was injected to mice in the blank control group from the tail vein. Modeling was conducted by injecting Con A at 3 microg/g body weight from the tail vein. Mice were sacrificed 8 h after modeling. Blood or tissue samples were collected to detect lab indicators such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil), tumor necrosis factor alpha (TNF-alpha), interferon gamma (INF-gamma), IL-4, IL-10, Fas, FasL, Bax, and bcl-2.. There was significant difference in all lab indicators between the normal group and the blank control group (P < 0.05, P < 0.01). Compared with the model group, ALT and AST levels were significantly lower in the RM group and the Bifendate group (P < 0.01); TBil significantly decreased in the RM group (P < 0.01). The expression level of TNF-alpha decreased in the RM group (P <0.05). The expression level of IFN-gamma decreased in the RM group and the YD group (P < 0.05). The expression level of IL-4 could be elevated in all medicated groups (P < 0.05). RM could elevate the expression level of IL-10 (P < 0.05). The expression level of Fas in the liver tissue decreased in the RM group and the YD group (P < 0.05). The expression level of FasL decreased and the expression of bcl-2 gene increased in the RM group (both P < 0.05). The expression level of Bax was down-regulated in the RM group and the YD group (P < 0.05). The ratio of bcl-2/Bax was up-regulated in the RM group (P < 0.05). Meanwhile, RM showed better effect in decreasing expressions of ALT and AST than HAS (P < 0.05). The effect of increasing IL-10 expression levels was better in the RM group than in the YD group (P < 0.01). The effect of decreasing expressions of Fas and FasL was better in the RM group than in the HAS group, the YD group, and the Bifendate group (P < 0.05). The effect of enhancing the expression of IL-10 in the liver tissue was better in the RM group than in the HAS group (P < 0. 05).. RM had protective effect on Con A induced acute immunological liver injury mice, which might be achieved by changing the immunological balance of Thl/Th2 factors (decreasing expressions of TNF-alpha and IFN-gamma, elevating expressions of IL-10 and IL-4) and regulating hepatocyte apoptosis-related factors (down-regulating gene expressions of Fas, FasL, and Bax; up-regulating bcl-2 gene expression, and up-regulating the bcl-2/Bax ratio).

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Drugs, Chinese Herbal; Female; Gene Expression; Hepatocytes; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic

Negative feedback immune mechanisms are essential for maintenance of hepatic homeostasis and prevention of immune-mediated liver injury. We show here that scavenger receptor A (SRA/CD204), a pattern recognition molecule, is highly up-regulated in the livers of patients with autoimmune or viral hepatitis, and of mice during concanavalin A (Con A)-induced hepatitis (CIH). Strikingly, genetic SRA ablation strongly sensitizes mice to Con A-induced liver injury. SRA loss, increased mortality and liver pathology correlate with excessive production of IFN-γ and heightened activation of T cells. Increased liver expression of SRA primarily occurs in mobilized hepatic myeloid cells during CIH, including CD11b(+) Gr-1(+) cells. Mechanistic studies establish that SRA on these cells functions as a negative regulator limiting T-cell activity and cytokine production. SRA-mediated protection from CIH is further validated by adoptive transfer of SRA(+) hepatic mononuclear cells or administration of a lentivirus-expressing SRA, which effectively ameliorates Con A-induced hepatic injury. Also, CIH and clinical hepatitis are associated with increased levels of soluble SRA. This soluble SRA displays a direct T-cell inhibitory effect and is capable of mitigating Con A-induced liver pathology.. Our findings demonstrate an unexpected role of SRA in attenuation of Con A-induced, T-cell-mediated hepatic injury. We propose that SRA serves as an important negative feedback mechanism in liver immune homeostasis, and may be exploited for therapeutic treatment of inflammatory liver diseases.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis, Animal; Interferon-gamma; Liver; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Scavenger Receptors, Class A; T-Lymphocytes

Aberrant expression of the chemokine CXC chemokine ligand (CXCL)10 has been linked to the severity of hepatitis C virus (HCV)-induced liver injury, but the underlying molecular mechanisms remain unclear. In this study, we describe a yet-unknown proapoptotic effect of CXCL10 in hepatocytes, which is not mediated through its cognate chemokine receptor, but the lipopolysaccharide receptor Toll-like receptor 4 (TLR4). To this end, we investigated the link of CXCL10 expression with apoptosis in HCV-infected patients and in murine liver injury models. Mice were treated with CXCL10 or neutralizing antibody to systematically analyze effects on hepatocellular apoptosis in vivo. Direct proapoptotic functions of CXCL10 on different liver cell types were evaluated in detail in vitro. The results showed that CXCL10 expression was positively correlated with liver cell apoptosis in humans and mice. Neutralization of CXCL10 ameliorated concanavalin A-induced tissue injury in vivo, which was strongly associated with reduced liver cell apoptosis. In vitro, CXCL10 mediated the apoptosis of hepatocytes involving TLR4, but not CXC chemokine receptor 3 signaling. Specifically, CXCL10 induced long-term protein kinase B and Jun N-terminal kinase activation, leading to hepatocyte apoptosis by caspase-8, caspase-3, and p21-activated kinase 2 cleavage. Accordingly, systemic application of CXCL10 led to TLR4-induced liver cell apoptosis in vivo.. The results identify CXCL10 and its noncognate receptor, TLR4, as a proapoptotic signaling cascade during liver injury. Antagonism of the CXCL10/TLR4 pathway might be a therapeutic option in liver diseases associated with increased apoptosis.

Topics: Animals; Apoptosis; Carbon Tetrachloride Poisoning; Caspases; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Concanavalin A; Hepatitis C; Hepatocytes; Humans; Liver; Mice; Receptors, CXCR3; Signal Transduction; Toll-Like Receptor 4

Inflammation plays a major role in immune-mediated liver injury, and exposure to environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to alter the inflammatory response as well as affect immune cell activity. In this study, we tested the hypothesis that TCDD pretreatment exacerbates hepatotoxicity in a murine model of immune-mediated liver injury induced by concanavalin A (Con A) administration. Mice were pretreated with 30 μg/kg TCDD or vehicle control on day zero and then given either Con A or saline intravenously on day four. Mice treated with TCDD did not develop liver injury; however, TCDD pretreatment increased liver injury resulting from moderate doses of Con A (4-10 mg/kg). TCDD-pretreated mice had altered plasma concentrations of inflammatory cytokines, including interferon gamma (IFNγ), and TCDD/Con A-induced hepatotoxicity was attenuated in IFNγ knockout mice. At various times after treatment, intrahepatic immune cells were isolated, and expression of cell activation markers as well as cytolytic proteins was determined. TCDD pretreatment increased the proportion of activated natural killer T (NKT) cells and the percent of cells expressing Fas ligand (FasL) after Con A administration. In addition FasL knockout mice and mice treated with CD18 antiserum were both protected from TCDD/Con A-induced hepatotoxicity, suggesting a requirement for direct cell-cell interaction between effector immune cells and parenchymal cell targets in the development of liver injury from TCDD/Con A treatment. In summary, exposure to TCDD increased NKT cell activation and exacerbated immune-mediated liver injury induced by Con A through a mechanism involving IFNγ and FasL expression.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Environmental Pollutants; Fas Ligand Protein; Gene Expression Regulation; Inflammation; Interferon-gamma; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Polychlorinated Dibenzodioxins; Time Factors

Interleukin (IL)-27, a newly discovered IL-12 family cytokine, is composed of p28 and EBI3. In this study, CD11c-p28(f/f) conditional knockout mice were generated to delete p28 specifically in dendritic cells (DCs). We demonstrated that in the absence of DC-derived p28, these mice were highly susceptible to both low and higher concentrations of concanavalin A (ConA) (5 mg/kg or 10 mg/kg), with extremely early and steady high levels of interferon-γ (IFN-γ) in sera. Neutralizing IFN-γ prevented ConA-induced liver damage in these mice, indicating a critical role of IFN-γ in this pathological process. Interestingly, the main source of the increased IFN-γ in CD11c-p28(f/f) mice was CD4+ T cells, but not natural killer T (NKT) cells. Depletion of CD4+ , but not NK1.1+ , cells completely abolished liver damage, whereas transferring CD4+ T cells from CD11c-p28(f/f) mice, but not from wild-type mice or CD11c-p28(f/f) -IFN-γ(-/-) double knockout mice to CD4(-/-) mice, restored the increased liver damage. Further studies defined higher levels of IFN-γ and T-bet messenger RNA in naïve CD4+ T cells from CD11c-p28(f/f) mice, and these CD4+ T cells were highly responsive to both low and higher concentrations of anti-CD3, indicating a programmed functional alternation of CD4+ T cells.. We provide a unique model for studying the pathology of CD4+ T cell-mediated liver injury and reveal a novel function of DC-derived p28 on ConA-induced fulminant hepatitis through regulation of the intrinsic ability for IFN-γ production by CD4+ T cells.

Topics: Animals; CD11c Antigen; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Disease Susceptibility; Dose-Response Relationship, Drug; Female; Interferon-gamma; Interleukin-17; Killer Cells, Natural; Male; Mice; Mice, Knockout

Exposure of rodents to perfluorooctane sulfonate (PFOS) induces pronounced hepatomegaly associated with significant alterations in hepatic histophysiology and immune status. The present investigation was designed to evaluate the effects of this perfluorochemical on immune-mediated liver damage. Accordingly, the influence of both sub-acute (10 days), moderate-dose (0.004%, w/w=6±1.3 mg/kg body weight/day) or short-term (28 days), low-dose (0.0001%, w/w=144±4 μg/kg body weight/day) dietary pretreatment with PFOS on the development of concanavalin A (Con A)-induced liver damage in mice was examined. With either regimen of exposure, PFOS exacerbated the acute liver damage caused by Con A, i.e., elevated serum levels of transaminases and led to more pronounced damage of hepatic tissue. This exacerbation was associated with either reduced (moderate dose) or unaltered (low dose) hepatic levels of the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ). Moreover, hepatic DNA fragmentation was enhanced, particularly following short-term exposure to a low-dose. Our findings suggest that exposure to PFOS may sensitize hepatic parenchymal cells to other insults that activate the hepatic immune system and thereby exacerbate liver damage during acute inflammation.

Topics: Alkanesulfonic Acids; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Disease Progression; DNA Fragmentation; Dose-Response Relationship, Drug; Environmental Pollutants; Fluorocarbons; Hepatomegaly; Immunologic Factors; Liver; Male; Mice; Mice, Inbred C57BL; Random Allocation; Time Factors; Transaminases

A novel in vitro system was employed to investigate liver tissue respiration (mitochondrial O2 consumption) in mice treated with concanavalin A (Con A). This study aimed to investigate hepatocyte bioenergetics in this well-studied hepatitis model.. C57Bl/6 and C57Bl/6 IFN-γ-/- mice were injected intravenously with 12 mg ConA/kg. Liver specimens were collected at various timepoints after injection and analyzed for cellular respiration and caspase activation. Serum was analyzed for interferon-gamma (IFN-γ) and aminotransferases. Fluorescence activated cell sorting analysis was used to determine the phenotype of infiltrating cells, and light and electron microscopy were used to monitor morphological changes. Phosphorescence analyzer that measured dissolved O2 as function of time was used to evaluate respiration.. In sealed vials, O2 concentrations in solutions containing liver specimen and glucose declined linearly with time, confirming zero-order kinetics of hepatocyte respiration. O2 consumption was inhibited by cyanide, confirming the oxidation occurred in the respiratory chain. Enhanced liver respiration (by ≈68%, p<0.02) was noted 3 hr after ConA treatment, and occurred in conjunction with limited cellular infiltrations around the blood vessels. Diminished respiration (by ≈30%, p=0.005) was noted 12 hr after ConA treatment, and occurred in conjunction with deranged mitochondria, areas of necrosis, and prominent infiltrations with immune cells, most significantly, CD3+NKT+ cells. Increases in intracellular caspase activity and serum IFN-γ and aminotransferase levels were noted 3 hr after ConA treatment and progressed with time. The above-noted changes were less pronounced in C57Bl/6 IFN-γ-/- mice treated with ConA.. Based on these results, liver tissue bioenergetics is increased 3 hr after ConA exposure. This effect is driven by the pathogenesis of the disease, in which IFN-γ and other cytokines contribute to. Subsequent declines in liver bioenergetics appear to be a result of necrosis and active caspases targeting the mitochondria within hepatocytes.

Topics: Animals; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Energy Metabolism; Interferon-gamma; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria, Liver; Oxygen Consumption; Transaminases

To investigate the expression and effect of farnesoid X receptor (FXR) on systemic lupus erythematosus (SLE) liver dysfunction and indicate its hepatoprotective role and the immunomodulatory property. mRNA and protein levels of FXR were determined on the liver specimens of SLE patients with liver injury as well as MRL/lpr rodent models. The FXR agonist chenodeoxycholic acid (CDCA) was administrated to MRL/lpr mice and the control BALB/C with concanavalin A (ConA)-induced liver injury. Blood samples were taken 0, 4, 8, 12, 16, and 24 h after ConA injection for the detection of serum ALT, AST, IFN-γ, TNF-α, and IL-6. FXR was down-regulated at both mRNA and protein levels in the liver specimens of SLE patients with liver injury as well as MRL/lpr mice. MRL/lpr was more susceptible to ConA than BALB/C indicated by significantly higher levels of aminotransferase and inflammatory cytokines. Activation of FXR by CDCA significantly reduced aminotransferase and inflammatory cytokines IFN-γ, TNF-α, and IL-6 caused by ConA injection in MRL/lpr mice. FXR was down-regulated in SLE patients as well as MRL/lpr lupus models with liver dysfunction. FXR activation ameliorated liver injury and suppressed inflammatory cytokines, thereby showing its protective function in SLE. Our findings raised the promising potential target for the treatment of SLE liver injury.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Case-Control Studies; Chemical and Drug Induced Liver Injury; Chenodeoxycholic Acid; Concanavalin A; Cytoprotection; Disease Models, Animal; Female; Humans; Inflammation Mediators; Interferon-gamma; Interleukin-6; Liver; Lupus Erythematosus, Systemic; Mice; Mice, Inbred BALB C; Mice, Inbred MRL lpr; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; Time Factors; Tumor Necrosis Factor-alpha

Fulminant hepatitis is mainly caused by excessive immune response-mediated liver injury and its definitive therapy is liver transplantation. Mesenchymal stem cells, one of the adult stem cells, have an immunomodulatory effect on immune cells and reside in various tissues. The aim of this study was to investigate a therapeutic effect of adipose tissue-derived mesenchymal stem cells (ASCs) on fulminant hepatitis induced by concanavalin A (ConA).. The ASCs were isolated from adipose tissues of BALB/c mice and confirmed by detection of cell surface markers and induction of multi-lineage differentiation. BALB/c mice were injected with ConA and treated with ASCs, phosphate buffered saline (PBS) or splenocytes (SPLCs). Survival rates, levels of serum liver enzymes, titers of serum cytokines, histopathology and localization of ASCs were investigated.. The survival rate of ASC-injected mice significantly increased compared to PBS or SPLC-injected mice. This effect was dependent on doses and timing of ASCs injected. Improvement of liver enzyme levels, histopathological changes and suppression of inflammatory cytokine production were observed in ASC-injected mice. Fluorescent stained ASCs were detected in inflammatory liver, but not in normal liver.. These results suggest that ASC treatment has a high potential to be an innovative therapy for fulminant hepatitis.

Topics: Adipose Tissue; Alanine Transaminase; Animals; Aspartate Aminotransferases; Biomarkers; Cell Differentiation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Female; Interferon-gamma; Liver; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Spleen; Time Factors; Tumor Necrosis Factor-alpha

We used Concanavalin A-induced liver injury to study the role of Interleukin 33 and its receptor ST2 in the induction of inflammatory pathology and hepatocellular damage.. We tested susceptibility to Concanavalin A induced hepatitis in ST2 deficient and wild type BALB/c mice and analyzed the effects of single injection of Interleukin 33 as evaluated by liver enzyme test, quantitative histology, mononuclear cell infiltration, cytokine production, intracellular staining of immune cells, and markers of apoptosis in the liver.. ST2 deficient mice developed significantly more severe hepatitis and had significantly higher number of mononuclear cells in the liver, CD4+ and CD8+ T cells, NKp46+ and CD3+NKp46+ cells, and F4/80+ macrophages. The level of pro-inflammatory cytokines in the sera and number of TNF alpha, IFN gamma, and IL-17 producing cells was higher in ST2 deficient mice. In contrast, number of CD4+Foxp3+ cells was statistically higher in wild type mice. Additionally, treatment of wild type mice with single (1 μg) injection of Interleukin 33 led to attenuation of the liver injury and milder infiltration of mononuclear cells, increase in total number of liver CD4+Foxp3+ cells and IL-4 producing CD4+ T cells. Interleukin 33 also suppressed the activation of caspase 3, prevented the expression of BAX, and enhanced the expression of antiapoptotic Bcl-2 in the liver.. We concluded that Interleukin 33/ST2 axis downregulated Concanavalin A-induced liver injury and should be evaluated as potential target in fulminant hepatitis in humans.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Humans; Inflammation Mediators; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Interleukins; Liver Failure, Acute; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Receptors, Interleukin; Signal Transduction; T-Lymphocyte Subsets

This study was designed to investigate the hepatic protective effect and the molecular mechanisms of andrographolide in concanavalin A-induced liver injury model. Results showed that andrographolide (Ag) attenuated concanavalin A (Con-A)-induced liver injury and inhibited hepatocyte apoptosis. Further results showed that oxidative stress response genes were significantly elevated during the pathogenesis induced by Con-A. Meanwhile, gadolinium chloride and N-acetyl-L-cysteine (NAC) treatment, which inactivates Kupffer cells or reduces reactive oxygen species, respectively, prevented the liver injury. So the messenger RNA levels of the oxidative response genes mentioned above were detected, and the following results showed that Ag treatment reduced their expression. Besides, serum lactate dehydrogenase and myeloperoxidase activity was significantly reduced by Ag. Finally, Ag treatment did not further reduce serum tumor necrosis factor-α production compared with NAC treatment alone. Thus, our results indicate that Ag prevents Con-A-induced liver injury and reduced the hepatic oxidative stress response. The hepatic protective effect of Ag indicates that Ag supplementation may be beneficial in the treatment of immune-mediated liver injury.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclooxygenase 2; Diterpenes; DNA Fragmentation; Glucose Transporter Type 1; Heme Oxygenase-1; Hepatocytes; Hypoxia-Inducible Factor 1, alpha Subunit; L-Lactate Dehydrogenase; Male; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II; Oxidative Stress; Peroxidase; Protective Agents; RNA, Messenger; Superoxide Dismutase; Superoxide Dismutase-1; Tumor Necrosis Factor-alpha

Antigen-presenting cells (APCs) are involved in the induction of liver inflammation. We investigated the roles of specific APCs in the pathogenesis of acute liver injury in mice.. We used concanavalin A (con A) or carbon tetrachloride to induce acute liver inflammation in mice and studied the roles of macrophages that express CCR9.. After injection of con A, we detected CCR9(+)CD11b(+)CD11c(-) macrophages that express tumor necrosis factor (TNF)-α in livers of mice, whereas CCR9(+)Siglec-H(+)CD11b(-)CD11c(low) plasmacytoid DCs (pDCs), which are abundant in normal livers, disappeared. The CCR9(+) macrophages were also detected in the livers of RAG-2(-/-) mice, which lack lymphocytes and natural killer T cells, after injection of con A. Under inflammatory conditions, CCR9(+) macrophages induced naive CD4(+) T cells to become interferon gamma-producing Th1 cells in vivo and in vitro. CCR9(-/-) mice injected with con A did not develop hepatitis unless they also received CCR9(+) macrophages from mice that received con A; more CCR9(+) macrophages accumulated in their inflamed livers than CCR9(+) pDCs, CCR9(-) pDCs, or CCR9(-) macrophages isolated from mice that had received injections of con A. Levels of CCL25 messenger RNA increased in livers after injection of con A; neutralizing antibodies against CCL25 reduced the induction of hepatitis by con A by blocking the migration of CCR9(+) macrophages and their production of TNF-α. Peripheral blood samples from patients with acute hepatitis had greater numbers of TNF-α-producing CCR9(+)CD14(+)CD16(high) monocytes than controls.. CCR9(+) macrophages contribute to the induction of acute liver inflammation in mouse models of hepatitis.

Topics: Animals; Carbon Tetrachloride; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatitis; Humans; Lymphocyte Activation; Macrophages; Mice; Mice, Knockout; Receptors, CCR; Th1 Cells; Tumor Necrosis Factor-alpha

The liver is the major metabolic organ and is subjected to constant attacks from chronic viral infection, uptake of therapeutic drugs, life behavior (alcoholic), and environmental contaminants, all of which result in chronic inflammation, fibrosis, and, ultimately, cancer. Therefore, there is an urgent need to discover effective therapeutic agents for the prevention and treatment of liver injury, the ideal drug being a naturally occurring biological inhibitor. Here we establish the role of IL30 as a potent antiinflammatory cytokine that can inhibit inflammation-induced liver injury. In contrast, interleukin (IL)27, which contains IL30 as a subunit, is not hepatoprotective. Interestingly, IL30 is induced by the proinflammatory signal such as IL12 through interferon-gamma (IFN-γ)/signal transducer and activator of transcription 1 signaling. In animal models, administration of IL30 by way of a gene therapy approach prevents and treats both IL12-, IFN-γ-, and concanavalin A-induced liver toxicity. Likewise, immunohistochemistry analysis of human tissue samples revealed that IL30 is highly expressed in hepatocytes, yet barely expressed in inflammation-induced tissue such as fibrous/connective tissue.. These novel observations reveal a novel role of IL30 as a therapeutic cytokine that suppresses proinflammatory cytokine-associated liver toxicity.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Genetic Therapy; Humans; In Vitro Techniques; Interferon-gamma; Interleukin-12; Interleukins; Liver; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Knockout; Minor Histocompatibility Antigens; Receptors, Cytokine; Receptors, Interleukin; STAT1 Transcription Factor

We previously reported that whey protein derived from cow milk suppressed inflammation in a variety of animal models. We developed a newly designed enteral formula using peptides prepared from whey protein and fermented milk product and investigated its ability to suppress inflammation in concanavalin A-induced hepatitis in mice.. C57BL/6 mice were fed a standard formula, AIN-93M, or enteral formula for 14 days, and then were intravenously administered concanavalin A. Inflammatory cytokines in plasma, liver, and spleen and markers of hepatic function in plasma were assessed at various time points. Livers were assessed for necrosis and apoptosis.. After concanavalin A treatment, plasma aspartate aminotransaminase, alanine aminotransferase, TNF-α, IL-6, and IFN-γ levels were significantly lower in mice fed enteral formula than in those fed standard formula or AIN-93M. Liver TNF-α and IFN-γ, and spleen IL-6 and IFN-γ levels were lower in enteral formula-fed mice than in standard formula-fed mice 2 h after concanavalin A treatment. Necrosis and apoptosis were suppressed in the livers of enteral formula-fed mice.. The new enteral formula is a potent novel immune-modulating diet that prevents aggravation of local inflammation by modulating systemic cytokine levels.

Topics: Alanine Transaminase; Animal Nutritional Physiological Phenomena; Animals; Apoptosis; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cultured Milk Products; Enteral Nutrition; Inflammation; Interferon-gamma; Interleukin-6; Liver; Male; Mice; Mice, Inbred C57BL; Milk Proteins; Necrosis; Spleen; Tumor Necrosis Factor-alpha; Whey Proteins

Curcumin has antiviral, antioxidant, and anti-inflammatory properties. However, the hepatoprotective effects and molecular mechanisms of curcumin on acute liver injury have not been carefully examined. The aims of this study were to examine the anti-inflammatory effect of curcumin on Concanavalin A (Con A) induced hepatitis, and to elucidate its underlying molecular mechanisms in mice. Mice received curcumin (200 mg/kg body weight) by gavage before Con A intravenous administration. We found that curcumin pretreatment was able to significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, curcumin pretreatment reduced intrahepatic expression of genes encoding pro-inflammatory molecules such as tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) as compared with the vehicle controls, but augmented anti-inflammatory cytokine interleukin 10 (IL-10) by enzyme linked immunosorbent assay (ELISA). Furthermore, the expression levels of Toll-like receptor (TLR) 2, TLR4 and TLR9 mRNA or protein in liver tissues were significantly lowered by curcumin treatment. Curcumin pretreatment did not affect hepatic Kupffer cell numbers after Con A injection. These results suggest that curcumin pretreatment protects against T cell-mediated hepatitis in mice. The beneficial effect of curcumin may be partly mediated by inhibiting the expression levels of TLR2, TLR4 and TLR9 in the liver.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Curcumin; Disease Models, Animal; Immunologic Factors; Interleukin-1; Kupffer Cells; Male; Mice; Mice, Inbred BALB C; Mitogens; RNA, Messenger; Toll-Like Receptors

We used concanavalin A (Con A)-induced liver injury to study the role of galectin-3 (Gal-3) in the induction of inflammatory pathology and hepatocellular damage. We tested susceptibility to Con A-induced hepatitis in galectin-3-deficient (Gal-3(-/-)) mice and analyzed the effects of pretreatment with a selective inhibitor of Gal-3 (TD139) in wild-type (WT) C57BL/6 mice, as evaluated by a liver enzyme test, quantitative histology, mononuclear cell (MNC) infiltration, cytokine production, intracellular staining of immune cells, and percentage of apoptotic MNCs in the liver. Gal-3(-/-) mice were less sensitive to Con A-induced hepatitis and had a significantly lower number of activated lymphoid and dendritic cells (DCs) in the liver. The level of tumor necrosis factor alpha (TNFα), interferon gamma (IFNγ), and interleukin (IL)-17 and -4 in the sera and the number of TNFα-, IFNγ-, and IL-17- and -4-producing cluster of differentiation (CD)4(+) cells as well as IL-12-producing CD11c(+) DCs were lower, whereas the number of IL-10-producing CD4(+) T cells and F4/80(+) macrophages were significantly higher in livers of Gal-3(-/-) mice. Significantly higher percentages of late apoptotic Annexin V(+) propidium-idodide(+) liver-infiltrating MNCs and splenocytes were observed in Gal-3(-/-) mice, compared to WT mice. Pretreatment of WT C57BL/6 mice with TD139 led to the attenuation of liver injury and milder infiltration of IFNγ- and IL-17- and -4-producing CD4(+) T cells, as well as an increase in the total number of IL-10-producing CD4(+) T cells and F4/80(+) CD206(+) alternatively activated macrophages and prevented the apoptosis of liver-infiltrating MNCs.. Gal-3 plays an important proinflammatory role in Con A-induced hepatitis by promoting the activation of T lymphocytes and natural killer T cells, maturation of DCs, secretion of proinflammatory cytokines, down-regulation of M2 macrophage polarization, and apoptosis of MNCs in the liver.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Dendritic Cells; Galectin 3; Lymphocyte Activation; Macrophage Activation; Male; Mice; Mice, Inbred C57BL

Glycine N-methyltransferase (GNMT) catabolizes S-adenosylmethionine (SAMe), the main methyl donor of the body. Patients with cirrhosis show attenuated GNMT expression, which is absent in hepatocellular carcinoma (HCC) samples. GNMT(-/-) mice develop spontaneous steatosis that progresses to steatohepatitis, cirrhosis, and HCC. The liver is highly enriched with innate immune cells and plays a key role in the body's host defense and in the regulation of inflammation. Chronic inflammation is the major hallmark of nonalcoholic steatohepatitis (NASH) progression. The aim of our study was to uncover the molecular mechanisms leading to liver chronic inflammation in the absence of GNMT, focusing on the implication of natural killer (NK) / natural killer T (NKT) cells. We found increased expression of T helper (Th)1- over Th2-related cytokines, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-R2/DR5, and several ligands of NK cells in GNMT(-/-) livers. Interestingly, NK cells from GNMT(-/-) mice were spontaneously activated, expressed more TRAIL, and had strong cytotoxic activity, suggesting their contribution to the proinflammatory environment in the liver. Accordingly, NK cells mediated hypersensitivity to concanavalin A (ConA)-mediated hepatitis in GNMT(-/-) mice. Moreover, GNMT(-/-) mice were hypersensitive to endotoxin-mediated liver injury. NK cell depletion and adoptive transfer of TRAIL(-/-) liver-NK cells protected the liver against lipopolysaccharide (LPS) liver damage.. Our data allow us to conclude that TRAIL-producing NK cells actively contribute to promote a proinflammatory environment at early stages of fatty liver disease, suggesting that this cell compartment may contribute to the progression of NASH.

Topics: Acute Disease; Adoptive Transfer; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Fatty Liver; Glycine N-Methyltransferase; Killer Cells, Natural; Lipopolysaccharides; Lymphocyte Depletion; Male; Mice; Mice, Knockout; Mitogens; TNF-Related Apoptosis-Inducing Ligand

Hepatitis represents a ubiquitous human health problem but effective therapies with limited side effects are still lacking. In this study, we investigated the effect and mechanism of TP-58, a novel thienopyridine derivative, on a murine fulminant hepatitis model induced by concanavalin A (ConA). We found TP-58 markedly alleviated ConA-caused liver injury and increased survival ratio of mice injected with a lethal dose of ConA. Oral administration of TP-58 significantly alleviated ConA-caused liver injury in mice by the reduction of serum aminotransferases and liver necrosis.The analysis of proinflammatory cytokines showed that TP-58 decreased both hepatic mRNA expressions and serum protein levels of TNF-α and IL-6. And the result from LPS-stimulated RAW 264.7 cells showed TP-58 suppressed the production of TNF-α, IL-6, and Nitro Oxide (NO) in the supernatant of LPS-stimulated RAW 264.7 cells. The study of activation of nuclear factor-κB (NF-κB) by electrophoretic mobility shift assay (EMSA) showed that TP-58 inhibited the activation of NF-κB both in vivo and in vitro. The inhibitory effect was also accompanied by a parallel reduction of IκB phosphorylation. These results indicate that TP-58 protects against liver injury by inhibition of the NF-κB-mediated inflammation and suggest a potential role of TP-58 against acute liver injury and other inflammatory diseases.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Female; I-kappa B Proteins; Inflammation; Interleukin-6; Lipopolysaccharides; Liver; Mice; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide; Phosphorylation; Proto-Oncogene Proteins c-akt; Pyridines; Thiophenes; Tumor Necrosis Factor-alpha

Corynebacterium parvum (CP), a kind of immunomodulator, has been well documented in many diseases. Non-cell C. parvum product (NCPP) is a newly-found nano-preparation. To investigate the effect of NCPP on Con A-induced murine severe hepatitis, we pretreated mice with NCPP intraperitoneally. After 12 h, ConA (25 μg/g body wt) was injected intravenously to provoke severe hepatitis and the degree of liver injury was evaluated by serum transaminase analysis and heptatic tissue pathology. Results have shown that levels of serum transaminase and degree of liver injury in ConA/NCPP groups had significantly declined than those in ConA/PBS groups. Notably, results of flow cytometry have demonstrated that activation of CD4+T cells in ConA/NCPP groups has been down-regulated, compared with ConA/PBS groups. Further, levels of serum and KC-related nitric oxide (NO) was displayed significantly lower in ConA/NCPP groups than those in ConA/PBS groups. The results indicate that NCPP may alleviate ConA-induced hepatitis by reducing CD4+T activation and NO production.

Topics: Animals; CD4-Positive T-Lymphocytes; Cell Extracts; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mitogens; Nitric Oxide; Propionibacterium acnes

High mobility group box chromosomal protein 1 (HMGB1) is an important proinflammatory molecule in many inflammatory disorders, but little is known about its role in acute-on-chronic liver failure (ACLF). Here, we investigated the relationship between the expression of HMGB1 and the disease onset and severity of ACLF patients and mice with acute liver injury/failure induced by concanavalin A (ConA). Peripheral blood mononuclear cells (PBMCs) and serum from ACLF patients were collected, and a mouse model of acute liver injury/failure was induced by ConA. HMGB1 mRNA expression in patient PBMCs or in murine livers and serum HMGB1 protein in ACLF patients and mice were assayed by RT-PCR and Western blotting, respectively. HMGB1 translocation in hepatocytes of ConA-treated mice was assessed by immunohistochemical staining. Up-regulated HMGB1 mRNA levels in PBMCs and accumulated protein in serum were both correlated with disease severity in ACLF patients. In the animal model, HMGB1 levels increased at 4 h and reached its peak value at 8-12 h after challenge with ConA, which suggests that HMGB1 is a relatively late proinflammatory cytokine compared with TNF-α. Translocation of HMGB1 from the nucleus to the cytoplasm in hepatocytes was correlated with the severity of liver injury in mice. While specific anti-HMGB1 antibodies and nicotine protected mice from acute liver injury/failure by reducing mortality and improving liver tissue injury, treatment with recombinant HMGB1 led to an increased mortality due to ConA challenge. Thus, the data from the present study suggest that HMGB1 plays a critical role in the systemic inflammation of ACLF and could be a potential therapeutic target in the treatment of ACLF.

Topics: Adult; Animals; Blotting, Western; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; End Stage Liver Disease; Female; HMGB1 Protein; Humans; Liver; Male; Mice; Mice, Inbred BALB C; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Young Adult

V-set and Ig domain-containing 4 (VSIG4, CRIg, or Z39Ig), a newly identified B7-related cosignaling molecule, is a complement receptor and a coinhibitory ligand that negatively regulates T-cell immunity. Despite its exclusive expression on liver Kupffer cells (KCs) that play key roles in liver tolerance, the physiological role of VSIG4 in liver tolerance remains undefined. Mice lacking VSIG4 had poor survival rates and severe liver pathology in a concanavalin A (ConA)-induced hepatitis (CIH) model, which could be prevented by adoptive transfer of VSIG4(+) KCs. The absence of VSIG4 rendered endogenous liver T- and natural killer T (NKT)-cells more responsive to antigen-specific stimulation and impaired tolerance induction in those cells against their cognate antigens. T-cell costimulation with VSIG4.Ig suppressed Th1-, Th2-, and Th17-type cytokine production and arrested the cell cycle at the G(0) /G(1) phase but did not induce apoptosis in vitro. VSIG4-mediated tolerance induction and cell-cycle arrest were further supported by down-regulation of G(1) phase-specific Cdk2, Cdk4, and Cdk6, and up-regulation of tolerance-inducing p27(KIP-1) in VSIG4.Ig-stimulated T-cells. Administration of soluble VSIG4.Ig to wildtype mice prevented CIH development and prolonged the survival of mice with established CIH.. Collectively, our results suggest that VSIG4(+) KCs play a critical role in the induction and maintenance of liver T- and NKT-cell tolerance, and that modulation of the VSIG4 pathway using a VSIG4.Ig fusion protein may provide useful immunological therapies against immune-mediated liver injury including autoimmune hepatitis.

Topics: Animals; Cell Proliferation; Cells, Cultured; Chemical and Drug Induced Liver Injury; Coculture Techniques; Concanavalin A; Cytokines; Galactosylceramides; Hepatitis; Immune Tolerance; Immunoglobulin G; Kupffer Cells; Liver; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Ovalbumin; Receptors, Complement; Signal Transduction; T-Lymphocytes

The overexpression of osteopontin is associated with various inflammatory liver diseases. Interestingly, each of these diseases is also associated with IL-17 expression. Therefore, we sought to determine whether there is any mechanistic link between osteopontin and IL-17. Herein we show that IL-17 and osteopontin levels were significantly increased in patients with chronic hepatitis B. We found that IL-17 and osteopontin levels increased similarly in mice with concanavalin A-induced hepatitis. Both osteopontin- and IL-17-deficient mice were resistant to concanavalin A-induced hepatic injury. In addition, osteopontin markedly induced IL-17 expression by leukocytes (from humans and mice). This effect could be blocked by a specific antibody against osteopontin. β3 integrin (one of the osteopontin receptors) was critically involved in the induction of IL-17 production by osteopontin. Osteopontin-induced IL-17 expression was mediated through the p38, JNK, and NF-κB pathways. These findings suggest that osteopontin regulates IL-17 production during the pathogenesis of hepatitis and provide new evidence for the critical roles of osteopontin and IL-17 in hepatitis.

Topics: Adult; Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Resistance; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Female; Hepatitis B, Chronic; Humans; Interleukin-17; JNK Mitogen-Activated Protein Kinases; Leukocytes, Mononuclear; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; Osteopontin; p38 Mitogen-Activated Protein Kinases; Peptides; Signal Transduction; Young Adult

During progression of liver disease, inflammation affects survival of hepatocytes. Endogenous release of adenosine triphosphate (ATP) in the liver activates purinergic P2 receptors (P2R), which regulate inflammatory responses, but little is known about the roles of these processes in the development of acute hepatitis.. We induced acute hepatitis in C57BL/6 mice by intravenous injection of concanavalin A and then analyzed liver concentrations of ATP and expression of P2R. We assessed P2Y(2)R(-/-) mice and C57BL/6 wild-type mice injected with suramin, a pharmacologic inhibitor of P2YR. Toxic liver failure was induced in mice by intraperitoneal injection of acetaminophen. Hepatocyte-specific functions of P2R signaling were analyzed in primary mouse hepatocytes.. Induction of acute hepatitis in wild-type C57BL/6 mice released large amounts of ATP from livers and induced expression of P2Y(2)R. Liver damage and necrosis were greatly reduced in P2Y(2)R(-/-) mice and C57BL/6 mice given injections of suramin. Acetaminophen-induced liver damage was reduced in P2Y(2)R(-/-) mice. Analysis of liver-infiltrating immune cells during acute hepatitis revealed that expression of P2Y(2)R in bone marrow-derived cells was required for liver infiltration by neutrophils and subsequent liver damage. Hepatic expression of P2Y(2)R interfered with expression of genes that regulate cell survival, and promoted tumor necrosis factor-α-mediated cell death, in a cell-autonomous manner.. Extracellular ATP and P2Y(2)R have cell-type specific, but synergistic functions during liver damage that regulate cellular immune responses and promote hepatocyte death. Reagents designed to target P2Y(2)R might be developed to treat inflammatory liver disease.

Topics: Acute Disease; Adenosine Triphosphate; Animals; Apoptosis; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatocytes; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Receptors, Purinergic P2Y2; Suramin

Infection with hepatitis B virus (HBV) continues to be a major global cause of acute and chronic liver disease with high mortality. Herein, we examined both the anti-HBV and hepatoprotective activity of α-DDB-FNC. In human HBV-transfected liver cell line HepG2.2.15, α-DDB-FNC effectively suppressed the secretion of HBV antigens in a time and dose-dependent manner with 25.11% inhibition on HBeAg and 43.68% on HBsAg at 2.5 μM on day 9. Consistent with the HBV antigen reduction, α-DDB-FNC (2.5 μM) also reduced HBV DNA level by 77.74% extracellularly and 78.94% intracellularly on day 9. In the duck hepatitis B virus (DHBV) infected ducks, after α-DDB-FNC was given once daily for 10 days, the serum and liver DHBV DNA levels were reduced markedly with 96.81% and 97.21% at 10 mgkg(-1) on day 10, respectively. In Con A-induced immunological liver-injury mice, α-DDB-FNC significantly inhibited the elevation of serum ALT, AST, TBiL and liver MDA, NO levels. Furthermore, significant improvement of the liver was observed after α-DDB-FNC treatment both in ducks and mice, as evaluated by the histopathological analysis. In conclusion, our results demonstrated that α-DDB-FNC possesses both antiviral activity against HBV and hepatoprotective effect to Con A-induced liver-injury mice.

Topics: Animals; Antiviral Agents; Benzodioxoles; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytidine; Cytoprotection; DNA Replication; DNA, Viral; Dose-Response Relationship, Drug; Ducks; Hep G2 Cells; Hepatitis B; Hepatitis B e Antigens; Hepatitis B Surface Antigens; Hepatitis B virus; Humans; Liver; Male; Mice; Time Factors; Virus Replication

The cyclin-dependent kinase (CDK) inhibitor flavopiridol is currently being tested in clinical trials as anticancer drug. Beyond its cell death-inducing action, we hypothesized that flavopiridol affects inflammatory processes. Therefore, we elucidated the action of flavopiridol on leukocyte-endothelial cell interaction and endothelial activation in vivo and in vitro and studied the underlying molecular mechanisms.. Flavopiridol suppressed concanavalin A-induced hepatitis and neutrophil infiltration into liver tissue. Flavopiridol also inhibited tumor necrosis factor-α-induced leukocyte-endothelial cell interaction in the mouse cremaster muscle. Endothelial cells were found to be the major target of flavopiridol, which blocked the expression of endothelial cell adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin), as well as NF-κB-dependent transcription. Flavopiridol did not affect inhibitor of κB (IκB) kinase, the degradation and phosphorylation of IκBα, nuclear translocation of p65, or nuclear factor-κB (NF-κB) DNA-binding activity. By performing a cellular kinome array and a kinase activity panel, we found LIM domain kinase-1 (LIMK1), casein kinase 2, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), CDK4, CDK6, CDK8, and CDK9 to be influenced by flavopiridol. Using specific inhibitors, as well as RNA interference (RNAi), we revealed that only CDK9 is responsible for the action of flavopiridol.. Our study highlights flavopiridol as a promising antiinflammatory compound and inhibition of CDK9 as a novel approach for the treatment of inflammation-associated diseases.

Topics: Animals; Cell Adhesion; Cell Communication; Cell Movement; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclin-Dependent Kinase 9; Disease Models, Animal; E-Selectin; Endothelium, Vascular; Flavonoids; Humans; Inflammation; Intercellular Adhesion Molecule-1; Leukocytes; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Piperidines; Protein Kinase Inhibitors; Vascular Cell Adhesion Molecule-1

Neutrophil depleted mice are protected from concanavalin A-mediated hepatitis, showing that neutrophils are critical for cellular liver damage. Interleukin-6 has pro- and anti-inflammatory properties and mediates neutrophil recruitment in diseases such as rheumatoid arthritis. In classic signaling, interleukin-6 binds to the membrane-bound interleukin-6-receptor and initiates signaling via gp130. In interleukin-6 trans-signaling, the agonistic soluble interleukin-6-receptor can form a soluble interleukin-6/interleukin-6-receptor complex and stimulate cells which only express gp130 but no interleukin-6-receptor. Interleukin-6 trans-signaling was shown to be important for liver regeneration and development of liver adenomas. Here, we show that blocking classic interleukin-6 signaling but not interleukin-6 trans-signaling reduced concanavalin A-induced liver damage in mice, with reduced liver STAT3 phosphorylation and liver neutrophil accumulation. However, the level of neutrophil-attracting chemokine KC is only reduced by inhibition of interleukin-6 trans-signaling. Analysis of circulating neutrophils after concanavalin A challenge revealed that classic interleukin-6 signaling is required for the mobilization of blood neutrophils. Reduced neutrophil infiltration was accompanied by increased levels of hepatoprotective monocyte chemoattractant protein-1 and reduced level of hepatodestructive interleukin-4. Abrogated classic interleukin-6 signaling in concanavalin A-mediated hepatitis exhibited liver-protective effects indicating that interleukin-6 classic but not interleukin-6 trans-signaling is responsible for liver damage. Classic interleukin-6 signaling is required to mount an efficient neutrophilia during concanavalin A-induced immune response, which might have clinical implications in the regard that blocking global interleukin-6 signaling pathways is a treatment option in different chronic inflammatory diseases.

Topics: Animals; Blotting, Western; Chemical and Drug Induced Liver Injury; Chemokine CCL2; Concanavalin A; Cytokine Receptor gp130; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Immunoenzyme Techniques; Interleukin-6; Liver; Liver Regeneration; Male; Mice; Mice, Inbred C57BL; Mitogens; Neutrophil Infiltration; Neutrophils; Receptors, Interleukin-6; Signal Transduction; STAT3 Transcription Factor

Osteopontin has been implicated in various inflammatory diseases including rheumatoid arthritis, multiple sclerosis, Crohn's disease, and fulminant hepatitis. Increased expression of osteopontin has been detected in pathological foci of these diseases. RA and fulminant hepatitis have been successfully treated by administration of neutralizing anti-osteopontin antibody in mice. However, rodent antibodies are highly immunogenic in humans and therefore limited in their clinical application. Here, a murine monoclonal antibody 23C3 against human osteopontin, was humanized by complementarity-determining region grafting method based on computer-assisted molecular modeling. The humanized version of 23C3, denoted as Hu23C3, was shown to possess affinity comparable to that of its parental antibody. Hu23C3 could also inhibit monocyte migration in response to osteopontin in vitro. Furthermore, in vivo data showed that Hu23C3 significantly protects mice from Concanavalin A (Con A) induced-liver injury in association with the reduction of transaminase activities and improvement of liver injury. Mechanistic studies demonstrated that Hu23C3 inhibited T and NKT cell infiltration, and activation of nuclear factor κB (NF-κB) in the liver, resulting in reduction of TNF-α and IFN-γ production. Thus, our data strongly support that the humanized anti-osteopontin antibody, Hu23C3, may have a potential for the treatment of T cell mediated-hepatitis in human.

Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Hepatitis; Humans; Immunoglobulin Variable Region; Interferon-gamma; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Models, Molecular; Molecular Sequence Data; Monocytes; NF-kappa B; Osteopontin; Protein Conformation; Tumor Necrosis Factor-alpha

Cell therapy has been used to attenuate liver injury. Here we evaluated whether genetic engineering of either bone marrow-derived mononuclear cells (MNC) or endothelial progenitor cells (EPC) many enhance their hepatoprotective properties.. Mice with ConA-induced hepatitis or with lethal fulminant hepatitis resulting from administration of an adenovirus encoding CD40L (AdCD40L) received an intra-splenic injection of saline or 2 × 10(6) unmodified MNC or EPC or the same cells transduced ex vivo with an adenovirus expressing luciferase (MNCLUC and EPCLUC) or encoding the hepatoprotective cytokine cardiotrophin-1 (CT-1) (MNCCT-1 and EPCCT-1). We analyzed the extent of liver damage, the intensity of inflammatory reaction, and animal survival.. Luciferase immunohistochemistry showed that after injection into the spleen, the engineered cells migrated efficiently to the damaged liver. In mice with ConA hepatitis EPCCT-1, but not other forms of cell therapy, significantly decreased serum transaminases and induced more intense histological improvement than other treatments. This superior therapeutic effect was associated with upregulation of cytoprotective molecules including IGF-I and EGF, lower expression of proinflammatory cytokines, IL-1b and TNFα, and decreased granzyme B levels. In AdCD40L-induced lethal fulminant hepatitis, EPCCT-1 also exceeded other cell therapies in attenuating the expression of proinflammatory mediators and hepatic injury enabling 35.7% survival while mortality was 100% in the other treatment groups.. Genetic engineering of EPC to overexpress CT-1 enhances the hepatoprotective properties of EPC and constitutes a therapy that deserves consideration for acute liver failure.

Topics: Adenoviridae; Animals; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Endothelial Cells; Genetic Engineering; Genetic Therapy; Liver Failure, Acute; Male; Mice; Mice, Inbred C57BL; Mitogens; Organic Cation Transport Proteins; Phenotype; Solute Carrier Family 22 Member 5; Stem Cell Transplantation; Stem Cells; Survival Rate; Transgenes

Increasing evidence suggests that a close interaction of Kupffer cells with T cells plays a central role in concanavalin A-induced hepatic injury in mice, but the underlying mechanisms remain obscure. The present study aimed to determine the relative roles of Th1 and Th17 type responses in concanavalin A-induced hepatic injury in mice, and to investigate whether or not Kupffer cells contribute to hepatic injury via a Th1 or Th17 type response-dependent pathway.. Immune-mediated hepatic injury was induced in C57BL/6 mice by intravenous injection of concanavalin A. Kupffer cells were inactivated by pretreatment with gadolinium chloride 24 hours before the concanavalin A injection. The interferon-gamma (IFN-gamma) and interleukin-17 (IL-17) pathways were blocked by specific neutralizing antibodies. Hepatic injury was assessed using serum transferase activity and pathological analysis. Expression of inflammatory cytokines within the liver was detected by real-time polymerase chain reaction and immunohistochemistry.. Neutralization of IFN-gamma significantly attenuated concanavalin A-induced hepatic injury. However, neutralization of IL-17 failed to suppress the injury. Inactivation of Kupffer cells by gadolinium chloride pretreatment protected against concanavalin A-induced injury and significantly reduced hepatic cytokine levels including TNF-alpha, IL-6 and IFN-gamma but not IL-17.. Our findings suggest that Kupffer cells contribute to concanavalin A-induced hepatic injury via a Th1 type response-dependent pathway and production of inflammatory cytokines including TNF-alpha, IL-6 and IFN-gamma.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Gadolinium; Interferon-gamma; Interleukin-17; Kupffer Cells; Mice; Mice, Inbred C57BL; Th1 Cells; Th17 Cells

Myeloid-derived suppressor cells (MDSCs) are getting increased attention as one of the main regulatory cells of the immune system. They are induced at sites of inflammation and can potently suppress T cell functions. In the current study, we demonstrate how activation of TRPV1 vanilloid receptors can trigger MDSCs, which in turn, can inhibit inflammation and hepatitis.. Polyclonal activation of T cells, following injection of concanavalin A (ConA), in C57BL/6 mice caused acute hepatitis, characterized by significant increase in aspartate transaminase (AST), induction of inflammatory cytokines, and infiltration of mononuclear cells in the liver, leading to severe liver injury. Administration of cannabidiol (CBD), a natural non-psychoactive cannabinoid, after ConA challenge, inhibited hepatitis in a dose-dependent manner, along with all of the associated inflammation markers. Phenotypic analysis of liver infiltrating cells showed that CBD-mediated suppression of hepatitis was associated with increased induction of arginase-expressing CD11b(+)Gr-1(+) MDSCs. Purified CBD-induced MDSCs could effectively suppress T cell proliferation in vitro in arginase-dependent manner. Furthermore, adoptive transfer of purified MDSCs into naïve mice conferred significant protection from ConA-induced hepatitis. CBD failed to induce MDSCs and suppress hepatitis in the livers of vanilloid receptor-deficient mice (TRPV1(-/-)) thereby suggesting that CBD primarily acted via this receptor to induce MDSCs and suppress hepatitis. While MDSCs induced by CBD in liver consisted of granulocytic and monocytic subsets at a ratio of ∼2∶1, the monocytic MDSCs were more immunosuppressive compared to granulocytic MDSCs. The ability of CBD to induce MDSCs and suppress hepatitis was also demonstrable in Staphylococcal enterotoxin B-induced liver injury.. This study demonstrates for the first time that MDSCs play a critical role in attenuating acute inflammation in the liver, and that agents such as CBD, which trigger MDSCs through activation of TRPV1 vanilloid receptors may constitute a novel therapeutic modality to treat inflammatory diseases.

Topics: Animals; Cannabidiol; CD11b Antigen; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Drug Discovery; Enterotoxins; Female; Hepatitis, Autoimmune; Immune Tolerance; Liver; Mice; Mice, Inbred C57BL; Myeloid Cells; Receptors, Chemokine; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; TRPV Cation Channels

C57BL/6 mice are widely used in biomedical research for the background of genetically engineered mice (GEM) and wild-type controls with the belief that the genetic background of GEM and control mice differ significantly by only one or more altered genes. This principle, however, does have limitations due in part to the existence of multiple substrains of C57BL/6 mice that should not be used interchangeably as they can differ both genetically and phenotypically. We show here that these mispairings do occur frequently and can lead to inaccurate and conflicting findings.

Topics: Acetaminophen; Analgesics, Non-Narcotic; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Knockdown Techniques; Genotype; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mitogen-Activated Protein Kinase 9; Mitogens

Hepatoprotective and antioxidant properties of Suaeda maritima (L.) Dumort on concanavalin-A induced stress in Wistar albino rats have been reported. Rats were administered with ethanolic extract of Suaeda maritimna at the concentration of 75, 150 and 300 mg/kg of body wt. for 9 days and concanavalin-A was administrated (iv) 12 mg/kg on 9th day. Rats in concanavalin-A administered group showed elevated levels of AST, ALT, ALP and bilurubin. Pretreatment of rats with ethanolic extract (300 mg/kg) significantly reduced these serum parameters compared to concavalin-A administered group. Histopathological examination of liver sections showed that, normal liver architecture was disturbed by hepatotoxin intoxication. The extract treated group and silymarin treated group retained the normal cell architecture, although less visible changes were observed. Preliminary phytochemical analysis showed the presence of triterpenioids and may be responsible for the hepatoprotective activity. The LD50 was calculated as 3 g/kg of the body weight. IC50 values of hydroxyl (52.21+/-1.32 microg/ml) and nitric oxide radicals (09.14+/-0.94 microg/ml) scavenging results showed comparable activity with vitamin-C. Results of this study may be useful for the development of herbal medicine from Suaeda maritima for the treatment of hepatitis.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Chenopodiaceae; Concanavalin A; India; Male; Plant Extracts; Plants, Medicinal; Rats; Rats, Wistar

Apoptosis is crucially involved in acute and chronic liver injury, including viral, cholestatic, toxic, and metabolic liver disease. Additionally, dysregulation of apoptosis signaling pathways has been implicated in hepatocarcinogenesis. The most prominent members of the apoptosis-mediating tumor necrosis factor receptor superfamily are the TNF-R1 (CD120a) and the CD95 (Apo-1/Fas) receptor. Although extensively studied, the intracellular signaling events in hepatocytes are only incompletely understood.. To examine the role of the caspase-8 homolog cellular FLICE-inhibitory protein (c-FLIP) in liver injury, we generated mice with hepatocyte specific deletion of c-FLIP. Three models of acute liver injury were employed: the agonistic anti-CD95 antibody Jo2, d-galactosamine and LPS (GalN/LPS), and concanavalin A.. Conditional ablation of c-FLIP in hepatocytes augmented liver injury and cell death in all three models of liver injury. CD95- and GalN/LPS-induced liver injury was ameliorated by a pancaspase inhibitor, while ConA-induced injury was unaffected by caspase inhibition. Augmented activation of the MAPK JNK was observed in parallel to liver injury in c-FLIP knockout mice in all injury models; however, inhibition of JNK only affected TNF- and ConA-mediated injury.. In summary, c-FLIP is a central regulator of cell death in hepatocytes, involving increased activation of caspases and the MAPK JNK.

Topics: Animals; Anthracenes; Apoptosis; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; fas Receptor; Female; Galactosamine; Hepatocytes; Lipopolysaccharides; MAP Kinase Signaling System; Mice; Mice, Knockout; Receptors, Death Domain

Inhibitor of apoptosis proteins (IAPs), such as X-linked or cellular IAP 1/2 (XIAP, cIAP1/2), are important regulators of apoptosis. IAP antagonists are currently under clinical investigation as anticancer agents. Interestingly, IAPs participate in the inflammation-associated TNF receptor signaling complex and regulate NFκB signaling. This raises the question about the role of IAPs in inflammation. Here, we investigated the anti-inflammatory potential of IAP inhibitors and the role of IAPs in inflammatory processes of endothelial cells.. In mice, the small molecule IAP antagonist A-4.10099.1 (ABT) suppressed antigen-induced arthritis, leukocyte infiltration in concanavalin A-evoked liver injury, and leukocyte transmigration in the TNFα-activated cremaster muscle. In vitro, we observed an attenuation of leukocyte-endothelial cell interaction by downregulation of the intercellular adhesion molecule-1. ABT did not impair NFκB signaling but decreased the TNFα-induced activation of the TGF-β-activated kinase 1, p38, and c-Jun N-terminal kinase. These effects are based on the proteasomal degradation of cIAP1/2 accompanied by an altered ratio of the levels of membrane-localized TNF receptor-associated factors 2 and 5.. Our results reveal IAP antagonism as a profound anti-inflammatory principle in vivo and highlight IAPs as important regulators of inflammatory processes in endothelial cells.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Arthritis, Experimental; Baculoviral IAP Repeat-Containing 3 Protein; Caspases; Cell Adhesion; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelial Cells; Enzyme Activation; HeLa Cells; Humans; Inhibitor of Apoptosis Proteins; Intercellular Adhesion Molecule-1; JNK Mitogen-Activated Protein Kinases; Leukocytes; Male; MAP Kinase Kinase Kinases; Mice; Mice, Inbred C57BL; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Proteasome Endopeptidase Complex; Protein Processing, Post-Translational; RNA Interference; Serum Albumin, Bovine; Time Factors; TNF Receptor-Associated Factor 2; TNF Receptor-Associated Factor 5; Transendothelial and Transepithelial Migration; Transfection; Tumor Necrosis Factor-alpha; Ubiquitin-Protein Ligases; Ubiquitination

The aims of the present study were to elucidate whether oxidative stress has a role in Con A-induced hepatitis and to examine if antioxidants may protect against liver damage in this model.. Hepatitis was induced in Balb/c mice by administration of Con A (18 mg/kg) to the tail vein. Liver enzymes and histology were determined 24 h after Con A injection. Tumor necrosis factor alpha (TNFalpha) and interleukin-10 (IL-10) levels were assayed 2 h after Con A injection. Hepatic malondialdehyde levels were measured at 1, 3, 8, 12, 18, and 24 h after Con A injection in order to examine the timing of free-radicals formation. Nuclear factor kappa B (NF-kappabeta) activation was determined by electrophoresis mobility shift assay (EMSA) 1 and 2 h after Con A injection. In separate experiments, mice were pretreated with either dimethylsulfoxide or dimethylthiourea before Con A inoculation. The antioxidant and NF-kappabeta inhibitor pyrrolidine dithiocarbamate (PDTC) was used as positive control.. Hepatic malondialdehyde levels increased 12, 18, and 24 h after Con A inoculation but not earlier. Serum levels of liver enzymes and TNFalpha, hepatic malondialdehyde, and protein carbonyls and the histologic necroinflammatory score were significantly reduced in the antioxidants-treated mice, while IL-10 levels were increased. Dimethylsulfoxide, dimethylthiourea, and PDTC inhibited oxidative stress, but only PDTC inhibited Con A-induced NF-kappaB activation.. Reactive oxygen species play a role in immune-mediated Con A-induced hepatitis probably secondary to immune-mediated liver damage. Scavenging of reactive oxygen species by antioxidants prevents hepatitis independently of NF-kappaB inhibition and may be a new therapeutic target in this experimental model.

Topics: Animals; Antioxidants; Chemical and Drug Induced Liver Injury; Concanavalin A; Dimethyl Sulfoxide; Disease Models, Animal; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Free Radical Scavengers; Interleukin-10; Liver; Male; Malondialdehyde; Mice; Mice, Inbred BALB C; NF-kappa B; Oxidative Stress; Proline; Thiocarbamates; Thiourea; Tumor Necrosis Factor-alpha

T cell-mediated hepatic damage plays a key role in the pathogenesis of liver diseases such as autoimmune hepatitis, viral hepatitis and acute liver failure. CpG-containing oligodeoxynucleotides (CpG ODN), a ligand for toll-like receptor (TLR) 9, is widely used as an immunological adjuvant. In the present study, we investigated the effect of CpG ODN on T cell-mediated liver injury in a murine model of concanavalin A (Con A)-induced hepatitis. We found that the aminotransferase level was significantly decreased in CpG ODN pretreated mice and the survival of the mice was markedly prolonged. CpG ODN pretreatment inhibited NF-kappaB DNA binding activity. As a result, the systemic/liver levels of TNF-alpha and IFN-gamma were significantly suppressed. Furthermore, the activation of inflammatory cells was diminished by CpG ODN pretreatment. These results suggest that CpG ODN pretreatment protects the mice from Con A-induced liver injury via inhibiting hepatocyte apoptosis, inflammation and activation of lymphocytes.

Topics: Animals; Cell Line; Cell Separation; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Antagonism; Flow Cytometry; Hepatitis; Interferon-gamma; Liver; Lymphocyte Activation; Macrophages; Male; Mice; Mice, Inbred C57BL; Mitogens; NF-kappa B; Oligodeoxyribonucleotides, Antisense; Transcriptional Activation; Tumor Necrosis Factor-alpha

A large amount of evidence suggests that monocytes/macrophages infiltration is implicated in a variety of inflammatory diseases including acute liver injury. Monocyte chemoattractant protein 1 (MCP-1) plays a crucial role in the process of macrophages recruitment. We herein presented a small-molecule library and a feasible quick screening method of evaluating potency of inhibition of chemotaxis of RAW264.7 cells stimulated by MCP-1. Fifty-three small molecules were synthesized and screened, and four compounds (2g, 2h, 4f, and 6h) showed inhibitory effects with IC(50) values range from 0.72 to 20.47 microM, with compound 4f being the most efficient. Further in vivo studies demonstrated that oral administration of 2g, 2h, 4f, or 6h decreases, most significantly for 4f, the serum levels of alanine aminotransaminase (ALT) and asparate aminotransaminase (AST) in ConA-induced acute livery injury BALB/c mice. Histopathological evaluation liver sections confirmed 4f as a potent, orally active compound for hepatoprotective effects against ConA-induced acute liver injury in BALB/c mice.

Topics: Animals; Cell Movement; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Drug Discovery; Drug Evaluation, Preclinical; Female; Liver Failure, Acute; Liver Function Tests; Mice; Mice, Inbred BALB C; Small Molecule Libraries; Stereoisomerism; Structure-Activity Relationship; Thiazolidinediones

The traditional Japanese (kampo) medicine inchinkoto (ICKT) is used in Eastern Asia as a choleretic and hepatoprotective agent. Previously, we reported that ICKT ameliorates murine concanavalin A (con A)-induced hepatitis via suppression of interferon (IFN)-gamma and interleukin (IL)-12 production. In the present study, we investigated the active ingredients of ICKT.. ICKT and extracts of its component herbs were fractionated, and their effects on liver injury and cytokine production in vivo (biochemical markers of liver injury and cytokine levels in serum) and in vitro (cytokine and nitrite production in the cultures of splenocytes and peritoneal macrophages).. Decoctions of component herbs, Artemisiae Capillari Spica (Artemisia capillaris Thunberg: 'Inchinko' in Japanese), Gardeniae Fructus (Gardenia jasminoides Ellis: 'Sanshishi') and Rhei Rhizoma (Rheum palmatum Linné: 'Daio') were administered orally. Inchinko and Sanshishi decreased serum transaminases and IFN-gamma concentrations. Examination of fractions of component herbs suggested that capillarisin, a component of Inchinko, has potent hepatoprotective activity in vivo. In in vitro studies, capillarisin and genipin, an intestinal metabolite of geniposide that is contained in Sanshishi, were examined. IFN-gamma production was significantly suppressed by capillarisin and genipin in con A-stimulated splenocyte culture. Genipin also suppressed IL-1beta, IL-6, and IL-12p70 synthesis. Capillarisin and genipin decreased nitrite release from IFN-gamma-stimulated macrophages.. These results suggested that both Inchinko and Sanshishi may contribute to the protective effects of ICKT against con A hepatitis. Capillarisin was found to be potently hepatoprotective, and genipin may also contribute, especially via modulation of cytokine production.

Topics: Animals; Artemisia; Chemical and Drug Induced Liver Injury; Chromones; Concanavalin A; Cytokines; Disease Models, Animal; Gardenia; Hepatitis; Interferon-gamma; Iridoid Glycosides; Iridoids; Liver; Macrophages; Magnoliopsida; Male; Medicine, Kampo; Mice; Mice, Inbred BALB C; Nitrites; Phytotherapy; Plant Extracts; Rheum; Transaminases

Liver diseases, caused by viral infection, autoimmune conditions, alcohol ingestion or the use of certain drugs, are a significant health issue, as many can develop into liver failure. Lactoferrin (Lac) is an iron-binding glycoprotein that belongs to the transferrin family. Owing to its multiple biological functions, Lac has been evaluated in a number of clinical trials to treat infections, inflammation and cancer.. The present study aims to reveal a profound hepatoprotective effect of Lac, using a mouse model of Concanavalin A (Con A)-induced hepatitis, which mimics the pathophysiology of human viral and autoimmune hepatitis.. C57Bl/6J mice were injected with bovine Lac following Con A challenge. The effects of Lac on interferon (IFN)-gamma and interleukin (IL)-4 expression were determined. The roles of Lac on T-cell apoptosis and activation, and leukocytes infiltration were examined.. The data demonstrated that the protective effect of Lac was attributed to its ability to inhibit T-cell activation and production of IFN-gamma, as well as to suppress IL-4 production by hepatic natural killer T cells.. These findings indicate a great therapeutic potential of Lac in treating in treating inflammatory hepatitis and possibly other inflammatory diseases.

Topics: Animals; Cattle; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Flow Cytometry; Hepatitis; Immunohistochemistry; Interferons; Interleukin-4; Lactoferrin; Liver; Male; Mice; Mice, Inbred C57BL; Probability; Random Allocation; Th1 Cells

Quantitative real-time reverse transcription-polymerase chain reaction (Q-PCR) has become an indispensable technique for accurate determination of gene expression in various samples. In mice, intravenous injection of concanavalin A (ConA) leads to acute hepatitis and liver injury. Functional studies based on this model have provided insights for understanding the mechanisms of liver injury. However, no data have been reported to validate reference genes during the progression of ConA-induced hepatitis (CIH). In this study, IkappaBalpha and C/EBPbeta messenger RNA (mRNA) levels were examined using Q-PCR with ACTB as the reference gene after ConA injection. However, we got inconsistent results with previous reports determining IkappaBalpha and C/EBPbeta mRNA expression levels. The results indicate the necessity for stability analysis of candidate reference genes in the CIH model. geNorm, NormFinder, and BestKeeper software analysis indicates that ACTB is the most unstable gene during CIH progression among the 10 reference genes tested, whereas RPLP0 or HPRT1 is the most stable one. This study demonstrates that some of the commonly used reference genes are inadequate for normalization of Q-PCR data due to their expression instability. Furthermore, this study validates HPRT1 and RPLP0 as appropriate reference genes for Q-PCR analysis in the CIH model.

Topics: Animals; CCAAT-Enhancer-Binding Protein-beta; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Gene Expression; Genes; I-kappa B Kinase; Male; Mice; Mice, Inbred C57BL; Reference Standards; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

To find new protein biomarkers for the detection and evaluation of liver injury and to analyze the relationship between such proteins and disease progression in concanavalin A (Con A)-induced hepatitis.. Twenty-five mice were randomly divided into five groups: an untreated group, a control group injected with phosphate buffered saline (PBS), and groups with Con A-induced hepatitis evaluated at 1, 3 and 6 h. Two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) were used to identify differences in protein expression among groups. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the results.. In mice with Con A-induced hepatitis, expression levels of four proteins were increased: RIKEN, fructose bisphosphatase 1 (fbp1), ketohexokinase (khk), and Chain A of class pi glutathione S-transferase. Changes in fbp1 and khk were confirmed by qRT-PCR.. Levels of two proteins, fbp1 and khk, are clearly up-regulated in mice with Con A-induced hepatitis.

Topics: Animals; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation; Humans; Liver; Male; Mice; Mice, Inbred BALB C; Proteome

Previous studies demonstrate that both membrane B7-H4 and B7-H4-Ig fusion protein could inhibit T-cell responses. In the present study, we explored the potential effect of B7-H4-Ig on liver injury in a hepatitis mouse model induced by concanavalin A (ConA). A B7-H4-Ig construct was introduced into animals by the hydrodynamic gene delivery approach. It was found that ectopic expression of B7-H4-Ig could inhibit ConA-induced elevation of serum levels of ALT and AST, suppress liver necrosis and even mortality of mice. Furthermore, we observed that pretreatment of B7-H4-Ig dramatically decreased serum levels and the expression of mRNA for IL-2, IFN-gamma and IL-4, but increased IL-10 in ConA-treated mice. Our results suggest that B7-H4-Ig may protect animals from liver injury induced by ConA, which could be associated with reduced serum levels for IL-2, IFN-gamma and IL-4 as well as enhanced IL-10 production.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; B7-1 Antigen; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Expression; Gene Transfer Techniques; Genetic Therapy; Humans; Immunoglobulin Fc Fragments; Immunoglobulin G; Interferon-gamma; Interleukin-10; Interleukin-2; Interleukin-4; Leukocytes, Mononuclear; Liver; Mice; Mice, Inbred BALB C; Necrosis; Recombinant Fusion Proteins; Survival Analysis; V-Set Domain-Containing T-Cell Activation Inhibitor 1

To explore the mechanisms of fulminant hepatitis (FH) in the early stages, and to determine the critical pathways in its initiation and progression.. Twelve BALB/c mice were divided into four groups: one group left as negative control and sacrificed immediately after injection of phosphate-buffered saline (PBS), and another three groups with concanavalin A (Con A) administration sacrificed at 1, 3, and 6 h after injection. Affymetrix GeneChip(R) Mouse 430 2.0 Array was employed to evaluate the expression profile of each of the 12 samples. Further analysis was done on the microarray data to extract the genes that were differentially expressed. Enrichment analysis was carried out to determine relevant pathways within which regulated genes were significantly enriched.. A total of 393, 8354 and 11 344 differentially expressed genes were found, respectively, at three time points. During 0-1 h and 1-3 h, most of the pathways enriched with regulated genes were related to immune response and inflammation, among which Toll-like receptor (TLR) signaling and mitogen-activated protein kinase (MAPK) signaling appeared during both phases, while cytokine-cytokine receptor interaction, apoptosis, T cell receptor signaling, and natural killer (NK) cell-mediated cytotoxicity pathways emerged during the second phase. Pathways found to be significant during 3-6 h were mostly related to metabolic processes.. The TLR signaling pathway dominates the early responses of Con A-induced FH in mice. It stimulates the production of type I cytokines, therefore recruiting and activating T/NK cells. Activated T/NK cells exert their cytotoxicity on hepatocytes through inducing death receptor-intermediated apoptosis, resulting in liver injury.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Male; Mice; Mice, Inbred BALB C; Microarray Analysis; Signal Transduction

To investigate the immunosuppressive effects of 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)VD(3)) on concanavalin A (ConA)-induced hepatitis and elucidate the action mechanism.. Female BALB/C mice were intravenously administered ConA (20 mg/kg) to induce acute immunological liver injury. Liver damage was evaluated in respect to serum alanine transaminase (ALT) level and liver histological changes. The proliferation of splenocytes was measured by using [(3)H]-thymidine incorporation. The cytokine level in the cultured splenocyte supernatant was determined by using enzyme-linked immunosorbent assays (ELISAs). The percentage of different splenic T cell subtypes was analyzed by using flow cytometry. The expression of splenic vitamin D receptor (VDR) mRNA and protein was detected by using real-time qRT-PCR and Western blot, respectively.. 1,25-(OH)(2)VD(3) (2.5 microg/kg, ip) significantly decreased the serum ALT levels and markedly attenuated the histological liver damage. The beneficial effect of 1,25-(OH)(2)VD(3) was associated with: (i) inhibition of CD4(+) T cell activation; (ii) reduction of interferon-gamma (IFN-gamma) and elevation of both IL-4 and IL-5 in supernatants of cultured splenocytes; and (iii) elimination of activated T cells by increasing VDR mRNA and protein expression in the spleen.. 1,25-(OH)(2)VD(3) had a significant protective effect against ConA-induced hepatitis, and its mechanism of action was associated with down-regulation of T cell-mediated immunity and up-regulation of VDR gene expression.

Topics: Alanine Transaminase; Animals; Calcitriol; CD4-CD8 Ratio; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Female; Gene Expression; Hepatitis, Autoimmune; Immunosuppressive Agents; Mice; Mice, Inbred BALB C; Receptors, Calcitriol; RNA, Messenger; Spleen; Vitamins

We have reported both T-cell-dependent and -independent hepatitis in immunocompetent and immunodeficiency mice, respectively, after intravenous injection of Con A in mice. The mode of hepatocyte cell death is different: autophagy for T-cell-independent hepatitis in contrast to apoptosis for T-cell-dependent one. In this study, we further demonstrate that liver blood vessels are the first target in both modes. The infused Con A bond to the hepatic vascular endothelial cells and cause its damage with autophagy. Before the elevation of the serum alanine aminotransferase at 6 h post-injection, the plasma leakage and hemorrhage occur at 1-3 h without inflammation. Con A induces autophagy of endothelial cells and hemorrhage that is enhanced by IFN-gamma. Using the endothelial cell line HMEC-1, a dose- and time-dependent cell death with autophagic LC3-II (microtubule-associated protein light chain 3) conversion was induced by Con A and was enhanced by IFN-gamma. In conclusion, Con A induced autophagy on hepatic endothelial cells; the damage of liver blood vessel occurs before the induction of T-cell-dependent hepatitis via apoptosis or T-cell-independent hepatitis via autophagy.

Topics: Animals; Autophagy; Blotting, Western; Cell Survival; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Endothelial Cells; Hepatocytes; Interferon-gamma; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, SCID; Time Factors

Carboxypeptidase R (CPR), also known as thrombin-activatable fibrinolysis inhibitor (TAFI), is an enzyme generated by proteolytic cleavage of its zymogen (proCPR). CPR removes the C-terminal arginine from inflammatory peptides such as C3a and C5a, bradykinin, enkephalin, and the thrombin-cleaved N-terminal fragment osteopontin (cleaved N-OPN). In the mouse model of concanavalin A (Con A)-induced immune-mediated fulminating hepatitis, cleaved N-OPN is one of the important peptides that induce the production of chemokines or cytokines. In the current study using proCPR deficient mice, we showed that injection of Con A into the mouse tail vein can induce a significantly higher lethality in proCPR-deficient female but not in male mice. Furthermore, a lack of CPR activity increased serum macrophage inflammatory protein-2 (MIP-2) and high-mobility group box 1 (HMGB1) levels after Con A injection. These in vivo findings suggest that CPR helps to protect against Con A-induced hepatitis.

Topics: Animals; Carboxypeptidase B2; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Mice

Concanavalin A (Con A)-induced acute liver injury model is well established as a model of T cell-mediated liver injury, in which T cells and NKT cells exert their cytotoxicity towards liver cells. In this study, we investigated the protective effects of CGX, a traditional Korean medicine against Con A-induced liver injury and its underlying mechanisms. After pretreatment with CGX (po, 50, 100 or 200 mg/kg) or distilled water once daily during 7 days, Con A (15 mg/kg) was injected intravenously. Thereafter serum level of AST and ALT, lipid peroxidation and cytokines in the liver tissue, and immune cell population in blood and the spleen were analyzed. CGX treatment reduced serum ALT, AST level in a dose-dependent manner. CGX treatment significantly decreased the lipid peroxidation and glutathione depletion in the liver tissue, and also lowered tissue levels of tumor necrotic factor-α and interferon-γ. CGX treatment attenuated the compositional alteration of Tc, Th, NKT, and B cells in blood as well as in the spleen. These results suggest that CGX has hepatoprotective property against Con A-induced liver injury through antioxidant action and immune regulation.

Topics: Animals; Body Weight; Catalase; Chemical and Drug Induced Liver Injury; Chromatography, High Pressure Liquid; Concanavalin A; Glutathione; Inflammation Mediators; Interferon-gamma; Liver; Liver Function Tests; Lymphocyte Subsets; Male; Malondialdehyde; Mass Spectrometry; Medicine, Korean Traditional; Mice; Mice, Inbred BALB C; Organ Size; Peptide Mapping; Plant Extracts; Spleen; Thymus Gland; Tumor Necrosis Factor-alpha

High-mobility group box 1 (HMGB1) is a nuclear factor released extracellularly as an early endogenous alarmin of inflammation following injury and as a late mediator of lethality in sepsis. Although HMGB1 has been implicated in acute lung injury, rheumatoid arthritis, and allograft rejection, its role in T-cell mediated hepatitis remains obscure. Here, we investigated the role and the underlying mechanisms of HMGB1 in concanavalin A (Con A) induced hepatic injury. We demonstrate that high levels of HMGB1 were detected in the necrotic area and in the cytoplasm of hepatocytes after Con A treatment. Administration of exogenous recombinant HMGB1 enhanced Con A-induced hepatitis, while blockade of HMGB1 protected animals from T cell-mediated hepatitis as evidenced by decreased serum transaminase, associated with reduced hepatic necrosis and mortality. Blockade of HMGB1 by a neutralizing antibody inhibited proinflammatory cytokine production, NFκB activity, and the late stage of T/NKT cell activation. These finding thus suggest a pivotal factor of HMGB1 in Con A-induced hepatitis. Blockage of extracellular HMGB1 may represent a novel therapeutic strategy to prevent hepatic injury in T cell-mediated hepatitis.

Topics: Animals; Antibodies, Blocking; Chemical and Drug Induced Liver Injury; Concanavalin A; Extracellular Space; HMGB1 Protein; Interferon-gamma; Liver; Lymphocyte Activation; Male; Mice; Models, Biological; Natural Killer T-Cells; Recombinant Proteins; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha; Up-Regulation

To explore the protective effect and its mechanism of Modified Xiaochaihu decoction(MXD) in the liver injury of mice. METHORDS: Using Reitman methord to examine serum ALT and ATS; Using sandwich enzyme immunoassay ABC-ELISA to examine serum TNF-α and IFN-γ.. Serum ALT and ATS of MXD large dose group and Xiaochaihu decoction (XD )group were lower than that of animal models group, there was significant difference among groups (P<0.05). There were not significant difference (P>0.05) between serum ALT and ATS of MXD small dose group and that of animal models group; MXD large dose group, XD group and Biphenyldimethylesterate (DDB) group are similar, no difference (P>0.05). Serum TNF-α and IFN-γ of MXD large dose group and XD group were significant lower than that of animal models group, there was significant difference among groups (P<0.05). Serum TNF-α and IFN-γ of XD group ware higher than that of MXD large dose group, there was significant difference among groups (P<0.05). MXD large dose group, XD group and DDB group were similar, no difference.. Xiaocaihu decoction possesses the effect of pro2 tection of hepatic impairment and the protective mechanism might be associated with the inhibition of apoptosis and immunomodulation.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Interferon-gamma; Male; Mice; Tumor Necrosis Factor-alpha

Immunity and metabolism are closely linked. The liver is an important metabolic organ in the body. However, the interactions between hepatocytes and the immune system are poorly understood. In mice developing concanavalin A (ConA)-induced hepatitis (CIH), we found extensive lipid accumulation in hepatocytes. Critical enzyme involved in fat synthesis such as stearoyl-CoA desaturase 1 (SCD1) was upregulated. When we injected ConA to SCD1-deficient mice, we found these mice to be highly resistant to CIH. The mechanisms of the protective effect of SCD1 deficiency might be attributed to the reduced leptin levels in those mice, which modulated critical cytokines and signaling pathways in CIH pathogenesis. In conclusion, our study suggests that SCD1 deficiency protects mice from liver injury in a leptin-dependent manner.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Fatty Liver; Gene Expression; Hepatocytes; Leptin; Lipid Metabolism; Liver; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mitogens; NF-kappa B p50 Subunit; RNA, Messenger; STAT1 Transcription Factor; Stearoyl-CoA Desaturase; Up-Regulation

Leptin-deficient ob/ob mice are resistant to dextran sulfate sodium (DSS)-induced colitis and Concanavalin A (Con A)-induced hepatitis. However, the signal transduction pathways involved have not been identified. The present study investigated the effect of leptin-induced STAT3 signaling in the DSS and Con A models. Mice carrying a leptin receptor (LEPR) gene mutant for Y1138 (s/s mice), with abrogated leptin-induced STAT3 signaling, were compared with wild-type (WT) and LEPR-deficient db/db mice. Administration of DSS to s/s mice resulted in a clinical score and colon shortening of intermediate severity compared with disease induced in WT and db/db mice-the latter group having the lowest disease severity. A comparable degree of inflammatory infiltrate and epithelial damage was observed in the colon of WT and s/s mice, and these parameters were reduced in db/db mice. Levels of IFN-gamma, IL-6, IL-10, and TNF-alpha were comparable in the colon of s/s and db/db mice, and a similar trend was observed for CXCL2. s/s and WT mice developed severe liver disease in response to Con A, whereas db/db mice were protected. However, Con A-induced serum IL-6 and TNF-alpha levels in s/s mice mimicked levels observed in db/db rather than WT mice. In conclusion, lack of leptin-induced STAT3 signaling is associated with reduced cytokine production following DSS and Con A administration, but it appears to sensitize mice to the effects of proinflammatory mediators.

Topics: Animals; Chemical and Drug Induced Liver Injury; Colitis; Concanavalin A; Cytokines; Dextran Sulfate; Inflammation; Mice; Receptors, Leptin; Signal Transduction; STAT3 Transcription Factor

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

Activation of invariant NKT (iNKT) cells in the liver is generally regarded as the critical step for Con A-induced hepatitis, and the role of NK cell receptors for iNKT cell activation is still controversial. In this study we show that blockade of the NKG2A-mediated inhibitory signal with antagonistic anti-NKG2A/C/E mAb (20d5) aggravated Con A-induced hepatitis in wild-type, Fas ligand (FasL)-mutant gld, and IL-4-deficient mice even with NK cell and CD8 T cell depletion, but not in perforin-, IFN-gamma-, or IFN-gamma- and perforin-deficient mice. Consistently, 20d5 pretreatment augmented serum IFN-gamma levels and perforin-dependent cytotoxicity of liver mononuclear cells following Con A injection, but not their FasL/Fas-dependent cytotoxicity. However, blockade of NKG2A-mediated signals during the cytotoxicity effector phase did not augment cytotoxic activity. Activated iNKT cells promptly disappeared after Con A injection, whereas NK1(-) iNKT cells, which preferentially expressed CD94/NKG2A, predominantly remained in the liver. Pretreatment with 20d5 appeared to facilitate disappearance of iNKT cells, particularly NK1(-) iNKT cells. Moreover, Con A-induced and alpha-galactosylceramide-induced hepatic injury was very severe in CD94/NKG2A-deficient DBA/2J mice compared with CD94/NKG2A-intact DBA/2JJcl mice. Overall, these results indicated that a NKG2A-mediated signal negatively regulates iNKT cell activation and hepatic injury.

Topics: Animals; Antibodies, Monoclonal; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Down-Regulation; Growth Inhibitors; Lymphocyte Activation; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Knockout; Natural Killer T-Cells; NK Cell Lectin-Like Receptor Subfamily C; NK Cell Lectin-Like Receptor Subfamily D; Receptors, Antigen, T-Cell; Signal Transduction

Intrahepatic immune tolerance is critical to prevent potentially harmful inflammatory responses. Tr1 regulatory T cell (Tr1 cell) that mainly produces interleukin 10 (IL-10) is an efficient regulator in immune tolerance. However, whether Tr1 regulatory T cells also participate in intrahepatic immune tolerance is not clear yet. In this study, we found that a single injection of a sublethal dose of concanavalin A (ConA) into BALB/c mice induced tolerance against ConA-induced liver damage within 8 days. Further, we found that ConA pretreatment elicited high frequency of Tr1 cells characterized as a higher secretion of IL-10, a lower production of IL-4 and no expression of Foxp3. Importantly, adoptive transfer of Tr1 cells into naïve mice remarkably reduced ConA-mediated liver injury. The exerted inhibition function was through IL-10-dependent pathway. Treatment with IL-10 neutralized antibody in vivo significantly blocked the protective effect of IL-10 in ConA/ConA mice. Taken together, these results demonstrated that Tr1 cells elicited by ConA pretreatment played an important role in inducing immune tolerance in the liver. Our finding provided new insights into the involvement of Tr1 regulatory T cells in preventing liver from immune-mediated injury.

Topics: Adoptive Transfer; Animals; Antibodies, Blocking; Chemical and Drug Induced Liver Injury; Concanavalin A; Forkhead Transcription Factors; Gene Expression Regulation; Immune Tolerance; Interleukin-10; Interleukin-4; Liver; Mice; Mice, Inbred BALB C; T-Lymphocytes, Regulatory; Th1 Cells

Vasoactive intestinal peptide (VIP) is well characterized as an endogenous anti-inflammatory neuropeptide and has a brand range of biological functions. In this study, we found increased endogenous VIP expression in mice with concanavalin A-induced hepatitis, a widely used experimental model of immune-mediated liver injury. We investigated further the effect of VIP administration on concanavalin A-induced liver injury. Compared with mice pretreated with PBS, mice pretreated with VIP exhibited much lower plasma levels of aminotransferases, less inflammatory infiltration in the liver and hepatocyte apoptosis. Meanwhile, VIP significantly inhibited the release of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) in concanavalin A-injected mice, but markedly elevated the production of anti-inflammatory cytokine interleukine-10 (IL-10). Further investigation demonstrated increased intracellular cAMP concentration after VIP administration, and showed that the protective effect of VIP on concanavalin A-induced hepatitis was mediated mainly through VIP receptor 1 (VPAC(1)). These results suggest that VIP is capable of attenuating immune-mediated liver injury in vivo. This effect is associated with its downregulation of critical inflammatory mediators and its upregulation of anti-inflammatory cytokine through VPAC(1), possibly via the cAMP-dependent pathway.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclic AMP; Disease Models, Animal; Gene Expression Regulation; Hepatocytes; Interferon-gamma; Interleukin-10; Liver; Male; Mice; Mice, Inbred C57BL; Receptors, Vasoactive Intestinal Polypeptide, Type I; Transaminases; Tumor Necrosis Factor-alpha; Vasoactive Intestinal Peptide

In this study, the possible protective effect of glycyrrhizin (GL), an active compound derived from licorice root, was examined on T cell-mediated liver injury in mice.. Mice were subjected to liver injury by intravenous injection of concanavalin A (Con A). They had been treated with GL (i.p.) 30 min before the injection. Liver injury was estimated by measuring serum levels of alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST), and by examining liver sections with hematoxylin-eosin staining. Expression of inducible nitric oxide synthase (iNOS) mRNA and protein in the liver was determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting.. Serum transaminases and hepatic iNOS levels increased with time after Con A treatment. Expression of iNOS mRNA in the liver was elevated for up to 8 h, and at 8 h, GL (ED(50): 10.5 mg/kg) suppressed the increases in AST and ALT in response to Con A. An increase in iNOS mRNA expression and protein was inhibited by treatment with GL. Furthermore, GL inhibited cell infiltration and the degeneration of hepatocytes in the liver of Con A-treated mice.. The present study suggests that the prevention by GL of Con A-induced hepatitis is due partly to the modulation of hepatic iNOS induction and of degeneration of hepatocytes.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Glycyrrhizic Acid; Humans; Liver; Male; Mice; Mice, Inbred BALB C; Nitric Oxide Synthase Type II; T-Lymphocytes

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

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Dexamethasone; Disease Models, Animal; Female; Hepatocytes; Liver; Male; Mice; Mice, Inbred ICR; Peroxidase; Protective Agents; Random Allocation; Saponins; Triterpenes

Cyclo-trans-4-l-hydroxyprolyl-l-serine (JBP485) was first isolated from Laennec (hydrolysate of human placenta). We thought it valuable to clarify the anti-hepatitis molecular mechanism of JBP485 to develop a new oral anti-hepatitis drug.. We investigated the hepatoprotective effect of JBP485 on immune-mediated, concanavalin A (Con A)-induced liver injury in mice. Mice were administered JBP485 before and after injection of Con A (10 mg/kg). Eight hours after Con A, the cytosolic enzyme activity (alanine aminotransferase, lactate dehydrogenase) in serum, and the enzyme activity or concentration (superoxide dismutase, maleic dialdehyde, myeloperoxidase, nitric oxide) in liver homogenate were determined. The liver slices were investigated to observe changes in histology. The effect of JBP485 on level of tumour necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecule-1 (ICAM-1) in liver were detected by immunohistochemistry. Hepatocyte DNA fragmentation was assayed by agarose gel electrophoresis and the transcription of the genes bax and bcl-2 in hepatocytes was determined by reverse transcription-polymerase chain reaction.. Con A increased the cytosolic and liver homogenate enzyme activity, and the concentrations of ICAM-1 and TNF-alpha, which were significantly inhibited by JBP485 administration. Also, the increase in DNA fragmentation and decrease in bcl-2/bax mRNA induced by Con A administration were significantly inhibited by JBP485.. These results indicated that immune-mediated liver damage can be prevented by JBP485, and that this is mainly associated with immunomodulatory effects on T cells and adhesion molecules, antioxidation, and inhibition of apoptosis.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytosol; DNA Fragmentation; Electrophoresis, Agar Gel; Female; Hepatocytes; Immunohistochemistry; Immunologic Factors; Intercellular Adhesion Molecule-1; Mice; Mice, Inbred BALB C; Peptides, Cyclic; Protective Agents; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha

It is well known that some intestinal bacteria, such as Escherichia coli, can produce a remarkable amount of molecular hydrogen (H(2)). Although the antioxidant effects of H(2) are well documented, the present study examined whether H(2) released from intestinally colonized bacteria could affect Concanavalin A (ConA)-induced mouse hepatitis. Systemic antibiotics significantly decreased the level of H(2) in both liver and intestines along with suppression of intestinal bacteria. As determined by the levels of AST, ALT, TNF-alpha and IFN-gamma in serum, suppression of intestinal bacterial flora by antibiotics increased the severity of ConA-induced hepatitis, while reconstitution of intestinal flora with H(2)-producing E. coli, but not H(2)-deficient mutant E. coli, down-regulated the ConA-induced liver inflammation. Furthermore, in vitro production of both TNF-alpha and IFN-gamma by ConA-stimulated spleen lymphocytes was significantly inhibited by the introduction of H(2). These results indicate that H(2) released from intestinal bacteria can suppress inflammation induced in liver by ConA.

Topics: Animals; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Escherichia coli; Hydrogen; Intestines; Male; Mice; Mice, Inbred C57BL; Mitogens

The role of coinhibition in an immune response is thought to be critical for the contraction of an adaptive immune response in its waning phases. We present evidence that B and T lymphocyte attenuator (BTLA) coinhibitory signaling is required to temper early inflammation. Using an in vivo Con A challenge model of acute hepatitis, we observed reduced survival and increased early serum cytokine secretion in BTLA(-/-) mice as compared with wild-type mice. In vitro, liver mononuclear cells from BTLA(-/-) mice are hyperresponsive to anti-CD3, Con A, and alpha-galactosylceramide stimulation and secrete higher levels of TNF-alpha, IFN-gamma, IL-2, and IL-4. We found this was in part due to negative regulation of NKT cells by BTLA, as early cytokine inhibition from whole liver mononuclear cells or purified NKT cells depends upon BTLA signaling. Overall, our data demonstrate that coinhibition is active in early immune responses through BTLA regulation of NKT cells.

Topics: Acute Disease; Animals; Chemical and Drug Induced Liver Injury; Clone Cells; Concanavalin A; Cytokines; Female; Inflammation Mediators; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Natural Killer T-Cells; Receptors, Immunologic; Signal Transduction; Time Factors

A pivotal role of phosphoinositide 3-kinase-gamma (PI3Kgamma) in inflammatory cell activation and recruitment makes it an attractive target for immunomodulatory therapy. In present study we investigated the therapeutic efficiency of AS605240, a selective PI3Kgamma inhibitor, on hepatitis and liver fibrosis in murine models induced by concanavalin A (ConA). Orally administration of AS605240 significantly improved survival, decreased the serum levels of alanine aminotransaminase (ALT), prevented inflammatory infiltration to liver in ConA-induced hepatitis. TNF-alpha and IFN-gamma at protein levels in serum and mRNA levels in liver were markedly reduced. Downregulated phospho-Akt level of inflammatory cells infiltrating the liver by AS605240 treatment was detected by immunohistochemistry analysis in liver and further confirmed by Western blotting analysis in splenocytes. In ConA-induced chronic liver fibrosis model, accumulation of smooth-muscle actin (SMA)-expressing cells was partially inhibited by AS605240 treatment. These observations suggest that AS605240 might be of therapeutic value for the treatment of ConA-induced hepatic injury.

Topics: Acute Disease; Animals; Chemical and Drug Induced Liver Injury; Class Ib Phosphatidylinositol 3-Kinase; Concanavalin A; Cytokines; Enzyme Inhibitors; Isoenzymes; Liver; Liver Cirrhosis; Mice; Mitogens; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Proto-Oncogene Proteins c-akt; Quinoxalines; Thiazolidinediones

The edible mushroom Lentinula edodes (shiitake) contains many bioactive compounds. In the present study, we cultivated L. edodes mycelia in solid medium and examined the hot-water extract (L.E.M.) for its suppressive effect on concanavalin A (ConA)-induced liver injury in mice. ConA injection into the tail vein caused a great increase in the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. The intraperitoneal administration of L.E.M. significantly decreased the levels of the transaminases. L.E.M. contains many bioactive substances, including polysaccharides and glucan, which could be immunomodulators. Since ConA-induced liver injury is caused by the activation of T cells, immunomodulating substances might be responsible for the suppressive effect of L.E.M. L.E.M. also contains phenolic compounds that are produced from lignocellulose by mycelia-derived enzymes. The major phenolics in L.E.M., syringic acid and vanillic acid, were intraperitoneally injected into mice shortly before the ConA treatment. Similar to L.E.M., the administration of syringic acid or vanillic acid significantly decreased the transaminase activity and suppressed the disorganization of the hepatic sinusoids. In addition, the inflammatory cytokines tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, and interleukin (IL)-6 in the serum increased rapidly, within 3 h of the ConA administration, but the administration of syringic acid or vanillic acid significantly suppressed the cytokine levels. Together, these findings indicate that the phenolic compounds in L.E.M. are hepatoprotective through their suppression of immune-mediated liver inflammation.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Dose-Response Relationship, Drug; Fungal Proteins; Gallic Acid; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Polysaccharides; Shiitake Mushrooms; T-Lymphocytes; Vanillic Acid

Thioredoxin binding protein 2 (TBP2) plays a regulatory role in lipid metabolism and immune regulation. We previously reported the effect of TBP2 loss-of-function on lipid metabolism using TBP2 knockout (TBP2KO) mice. In this study, we employed TBP2 transgenic (TBP2TG) mice to analyze the in vivo effect of TBP2 gain-of-function. We revealed a decrease in the percentage of hepatic natural killer T (NKT) cells in TBP2KO mice and an increase in the percentage of hepatic NKT cells in TBP2TG mice. The TBP2KO mice were resistant to concanavalin A (ConA)-induced hepatitis, but they were highly susceptible to other types of hepatitis. TBP2 modulates lipid metabolism as well as NKT cell activity. Moreover, TBP2 expression was increased significantly in klotho-deficient mice, which exhibit a syndrome resembling aging human phenotypes. TBP2 may play multiple roles in lipid metabolism, innate immunity, and aging.

Topics: Aging; Animals; Antigens, CD1d; Carrier Proteins; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Glucuronidase; Hepatocytes; Humans; Immunity, Innate; Insulin; Interleukin-2 Receptor beta Subunit; Klotho Proteins; Lipid Metabolism; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Natural Killer T-Cells; Thioredoxins

An intravenous injection of Concanavalin A (Con A) elevated the serum level of alanine aminotransferase (ALT) activity, a marker for liver damage, and an oral administration of PDE7A inhibitor SUN11817 suppressed the increase of ALT activity in a dose-dependent manner. Histological analysis revealed that Con A injection caused extensive liver damage, and that the SUN11817 treatment improved the degenerative change in the liver. In addition, SUN11817 inhibited not only the production of IL-4 and TNF-alpha in the Con A-induced hepatitis model but also that in vitro by murine splenocytes stimulated with alpha-galactosylceramide, an activator specific for NKT cells. The Con A injection to mice also induced expression of Fas ligand (FasL) on NKT cells, which was significantly prevented by SUN11817. As NKT cells are known to contribute to the pathogenesis in Con A-induced hepatitis by producing cytokines such as IL-4 and TNF-alpha and inducing FasL-mediated hepatocyte injury, it is thought that PDE7A inhibitor SUN11817 improves liver injury in the Con A model by blocking cytokine production and FasL expression in NKT cells. PDE7A might be a novel pharmaceutical target for hepatitis.

Topics: Alanine Transaminase; Animals; Cell Count; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclic Nucleotide Phosphodiesterases, Type 7; Fas Ligand Protein; Female; Galactosylceramides; Interleukin-4; Liver; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Pyrazoles; Spleen; Thiophenes; Tumor Necrosis Factor-alpha

TLR3 is known to respond to dsRNA from viruses, apoptotic cells, and/or necrotic cells. Dying cells are a rich source of ligands that can activate TLRs, such as TLR3. TLR3 expressed in the liver is likely to be a mediator of innate activation and inflammation in the liver. The importance of this function of TLR3 during acute hepatitis has not previously been fully explored. We used the mouse model of Con A-induced hepatitis and observed a novel role for TLR3 in hepatocyte damage in the absence of an exogenous viral stimulus. Interestingly, TLR3 expression in liver mononuclear cells and sinus endothelial cells was up-regulated after Con A injection and TLR3(-/-) mice were protected from Con A-induced hepatitis. Moreover, splenocytes from TLR3(-/-) mice proliferated less to Con A stimulation in the presence of RNA derived from damaged liver tissue compared with wild-type (WT) mice. To determine the relative contribution of TLR3 expression by hematopoietic cells or nonhematopoietic to liver damage during Con A-induced hepatitis, we generated bone marrow chimeric mice. TLR3(-/-) mice engrafted with WT hematopoietic cells were protected in a similar manner to WT mice reconstituted with TLR3(-/-) bone marrow, indicating that TLR3 signaling in both nonhematopoietic and hematopoietic cells plays an important role in mediating liver damage. In summary, our data suggest that TLR3 signaling is necessary for Con A-induced liver damage in vivo and that TLR3 regulates inflammation and the adaptive T cell immune response in the absence of viral infection.

Topics: Acute Disease; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Expression Regulation; Hematopoietic Stem Cells; Hepatocytes; Inflammation; Liver; Mice; T-Lymphocytes; Toll-Like Receptor 3

To test the effect of 5-(4-methoxybenzylidene)-2-thioxo-dihydropyrimidine-4, 6 (1H, 5H)-dione (SKLB-102) on acute hepatic inflammatory induced by concanavalin A (ConA) in mice.. The inhibitive effect of SKLB-102 on RAW264.7 cell migration induced by recombinant rat monocyte chemotactic protein-1 (MCP-1) was tested. The serum from the ConA-treated mice was collected after intragastric administration of SKLB-102 at the dose of 50 mg/kg bodyweight. The serum AST and ALT were determined by an automatic analyzer, and the serum TNF-alpha was determined with enzyme-linked immunosorbent assay (ELISA) kits. The liver samples were fixed in 10% formalin, embedded in paraffin, sectioned and then stained with hematoxylin and eosin for histological examinations.. SKLB-102 markedly reduced cell migrations, successfully reduced serum AST, ALT and down-regulated TNF-alpha.. SKLB-102 is likely to suppress the occurrence of Con A-induced hepatitis by suppressing macrophages migration and TNF-alpha releases.

Topics: Acute Disease; Animals; Cell Line; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Liver; Macrophages; Male; Mice; Mice, Inbred BALB C; Random Allocation; Thiazolidinediones

The aim of this study was to evaluate the therapeutic potential of bone marrow mesenchymal stem cells (MSC) on acute liver injury induced by concanavalin A (ConA). MSCs were isolated from male C57BL/6 mice and cultured, and a ConA-induced acute liver injury model was used. MSCs were systemically infused immediately after mice were challenged with ConA, control mice received only saline infusion. 24 hours after MSC transplantation, the level of serum aminotransferases, histologic change and in situ apoptosis of cells were detected, the expression of inflammatory mediators were examined by real-time RT-PCR. The results indicated that MSC transplantation significantly reduced ConA-induced acute liver injury, including the decrease of the level of serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST) and the extenuation of liver necrosis and in situ apoptosis. Furthermore, after MSC infusion the expression of TNF-alpha, IFN-gamma in liver decreased greatly (p<0.05) with no statistical difference in the expression of iNOS, IL-2 and IL-10 (p>0.05). It is concluded that the systemic infusion of MSCs can alleviate ConA induced acute liver injury in mice.

Topics: Animals; Bone Marrow Cells; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-10; Interleukin-2; Liver; Male; Mesenchymal Stem Cell Transplantation; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II; Treatment Outcome; Tumor Necrosis Factor-alpha

To investigate the protective effects of Angelica sinensis polysaccharide on immunological liver injury induced by concanavalin A (ConA).. Sixty NIH mice were randomly divided into 6 groups as normal group, model group, biphenyl group, Angelica sinensis polysaccharide high does group, Angelica sinensis polysaccharide middle dose group and Angelica sinensis polysaccharide low dose group. Immunological liver injury in mice was induced by ConA (20 mg/kg) by injection via tail vein, the control group received saline alone. In the treatment groups, each group was administrated via gavage daily. The control group was given equal volume of saline. Liver index, thymus index and spleen index, contents of serum ALT, AST, TB and NO in serum and TNF-alpha, IL-1beta, ITN-gamma in liver homogenate were measured.. Angelica sinensis polysaccharide remarkably increased the levels of liver index, thymus index and spleen index, decreased the contents ALT, AST, TB and NO levels in serum, and TNF-alpha, IL-1beta, ITN-gamma in liver homogenate (P < 0.05).. Angelica simesis polysaccharide haride can obviously protect immunological injury liver in mice and between the dose range of 30-120 mg/kg in a dose-dependent manner. Its mechanism may be relate to inhibiting T lymphocyte activity and ITN-gamma, TNF-alpha, IL-1beta, NO release.

Topics: Alanine Transaminase; Angelica sinensis; Animals; Aspartate Aminotransferases; Biphenyl Compounds; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Interferon-gamma; Interleukin-1; Liver; Male; Mice; Mice, Inbred Strains; Nitric Oxide; Polysaccharides; Protective Agents; Tumor Necrosis Factor-alpha

Periploca sepium Bge, a traditional Chinese herb medicine, is widely used for treating rheumatoid arthritis in china. Periplocoside A (PSA), a pregnane glycoside, is a new nature product compound isolated from P. sepium Bge. We examined the protective effects of PSA, on concanavaline A (ConA)-induced hepatitis. Pretreatment with PSA dramatically ameliorated ConA-induced liver injury, which was characterized by reducing serum alanine transaminase (ALT), pathogenic cytokines of interleukin (IL)-4 and interferon (IFN)-gamma levels, impeding the liver necrosis, and thus elevating the survival rate. In vitro, PSA inhibited IL-4 and IFN-gamma productions of alpha-galactosylceramide (alpha-GalCer) or anti-CD3-activated Natural killer T (NKT) cells. Enzyme Linked Immunosorbent Assay (ELISA) and Reverse Transcription Polymerase Chain Reaction (RT-PCR) assays revealed PSA suppressed IL-4 transcription and IFN-gamma translation. In conclusion, PSA had significantly preventative effect on ConA-induced hepatitis, which was closely associated with inhibition of NKT-derived inflammatory cytokine productions. These findings suggested that PSA has the therapeutic potential for treatment of human autoimmune-related hepatitis.

Topics: Alanine Transaminase; Animals; Antineoplastic Agents, Phytogenic; CD3 Complex; Cell Proliferation; Cell Separation; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Flow Cytometry; Galactosylceramides; Glycosides; Indicators and Reagents; Killer Cells, Natural; Liver Function Tests; Lymphocyte Culture Test, Mixed; Lymphocytes; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Monocytes; Oligosaccharides; Periploca; Pregnenes

Natural killer T-cell (NKT) regulatory lymphocytes have been shown to behave differently in various immune settings. The aim of the present study was to determine the effect of microenvironmental signaling on NKT polarization and the process of active CD8 and NKT intrahepatic lymphocyte sequestration. In an in vitro assay, double negative (DN) NKT hybridoma cells were incubated with Hep3B hepatoma cells. This caused a significant increase in the secretion of alpha-fetoprotein (AFP) from Hep3B cells. When NKT cells were exposed to beta-glucoslyceramide (beta-GC) prior to incubation, Hep3B cells exhibited increased proliferation, increased IFN secretion, and reduced AFP secretion. In vivo, the adoptive transfer of naïve DN NKT cells into athymic nude-nu mice transplanted with human Hep3B hepatocellular carcinoma (HCC) caused accelerated tumor growth. This effect was inhibited by prior ex vivo exposure of DN NKT lymphocytes to beta-GC. To assess the effect of the immunological environment on NKT cells, immune mediated hepatitis and colitis were induced simultaneously in mice. Induction of TNBS colitis prior to administration of concanavalin A (Con A) hepatitis resulted in an aggravation of the liver damage caused by Con A hepatitis alone. This effect was associated with reduced intrahepatic CD8+ T cell trapping and an increase in intrahepatic NKT cells. The presence of different ligands altered host microenvironment signaling and influenced the fate and polarization of NKT cells and the sequestration of active intrahepatic lymphocytes. These data support the notion that NKT regulatory lymphocytes have an inherent plasticity that may be important for their regulatory function.

Topics: Animals; Benzoates; CD8-Positive T-Lymphocytes; Cell Line; Cell Line, Tumor; Cell Proliferation; Chemical and Drug Induced Liver Injury; Colitis; Concanavalin A; Cytokines; Disease Models, Animal; Glycosphingolipids; Humans; Immunity; Killer Cells, Natural; Ligands; Liver Neoplasms, Experimental; Lymphocyte Subsets; Male; Mice; Mice, Nude; Signal Transduction; Xenograft Model Antitumor Assays

Concanavalin A (Con A)-induced injury is an established natural killer T (NKT) cell-mediated model of inflammation that has been used in studies of immune liver disease. Extracellular nucleotides, such as adenosine triphosphate, are released by Con A-stimulated cells and bind to specific purinergic type 2 receptors to modulate immune activation responses. Levels of extracellular nucleotides are in turn closely regulated by ectonucleotidases, such as CD39/NTPDase1. Effects of extracellular nucleotides and CD39 on NKT cell activation and upon hepatic inflammation have been largely unexplored to date. Here, we show that NKT cells express both CD39 and CD73/ecto-5'-nucleotidase and can therefore generate adenosine from extracellular nucleotides, whereas natural killer cells do not express CD73. In vivo, mice null for CD39 are protected from Con A-induced liver injury and show substantively lower serum levels of interleukin-4 and interferon-gamma when compared with matched wild-type mice. Numbers of hepatic NKT cells are significantly decreased in CD39 null mice after Con A administration. Hepatic NKT cells express most P2X and P2Y receptors; exceptions include P2X3 and P2Y11. Heightened levels of apoptosis of CD39 null NKT cells in vivo and in vitro appear to be driven by unimpeded activation of the P2X7 receptor.. CD39 and CD73 are novel phenotypic markers of NKT cells. In turn, CD39 expression [corrected] modulates nucleotide-mediated cytokine production by, and limits apoptosis of, hepatic NKT cells. Deletion of CD39 is protective in [corrected] Con A-induced hepatitis. This study illustrates a [corrected] role for purinergic signaling in NKT-mediated mechanisms that result in liver immune injury.

Topics: 5'-Nucleotidase; Adenosine Triphosphate; Animals; Antigens, CD; Apoptosis; Apyrase; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Killer Cells, Natural; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Nucleotides; Receptors, Purinergic P2; Receptors, Purinergic P2X7; T-Lymphocyte Subsets

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

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interleukin-10; Interleukin-2; Mice; Mice, Knockout; Suppressor of Cytokine Signaling 1 Protein; Suppressor of Cytokine Signaling Proteins; T-Lymphocytes, Regulatory

The aim of this study was to investigate the effect of the novel antihepatitis drug bicyclol on the gene expression profiles in concanavalin A (Con A) intoxicated mice by using cDNA microarray analysis. Bicyclol (250 mg x kg(-1)) was given orally to mice three doses before Con A intravenous injection (26.5 mg x kg(-1)). Serum levels of aminotransferases were examined by biochemical methods. Liver mRNA was extracted and reversely transcribed to cDNA with the incorporation of labeled Cy3-dUTP and Cy5-dUTP, separately. The probes were hybridized to the cDNA microarray. The acquired image was scanned and analyzed by Cenepix Pro 3.0 software. Microarray analysis showed that 287 genes exhibited differential expression in bicyclol group, in which 121 genes were up-regulated and 166 genes were down-regulated comparing with that of untreated Con A intoxicated mice. The differential gene expression after bicyclol treatment was involved in the biotransformation, protein synthesis, degradation and circadian rhythm, proliferation and signal transduction. Bicyclol might regulate a series of genes expressions in Con A intoxicated mice.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Biphenyl Compounds; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Expression Profiling; Male; Mice; Mice, Inbred ICR; Oligonucleotide Array Sequence Analysis; Random Allocation

Although concanavalin A (Con-A)-induced experimental hepatitis is thought to be induced by activated T cells, natural killer T (NKT) cells, and cytokines, precise mechanisms are still unknown. In the current study, we investigated the roles of Kupffer cells, NKT cells, FasL, tumor necrosis factor (TNF), and superoxide in Con-A hepatitis in C57BL/6 mice. Removal of Kupffer cells using gadolinium chloride (GdCl(3)) from the liver completely inhibited Con-A hepatitis, whereas increased serum TNF and IFN-gamma levels were not inhibited at all. Unexpectedly, anti-FasL antibody pretreatment did not inhibit Con-A hepatitis, whereas it inhibited hepatic injury induced by a synthetic ligand of NKT cells, alpha-galactosylceramide. Furthermore, GdCl(3) pretreatment changed neither the activation-induced down-regulation of NK1.1 antigens as well as T cell receptors of NKT cells nor the increased expression of the CD69 activation antigen of hepatic T cells. CD68(+) Kupffer cells greatly increased in proportion in the early phase after Con-A injection; this increase was abrogated by GdCl(3) pretreatment. Anti-TNF antibody (Ab) pretreatment did not inhibit the increase of Kupffer cells, but it effectively suppressed superoxide/reactive oxygen production from Kupffer cells and the resulting hepatic injury. Conversely, depletion of NKT cells in mice by NK1.1 Ab pretreatment did suppress both the increase of CD68(+) Kupffer cells and Con-A hepatitis. Consistently, the diminution of oxygen radicals produced by Kupffer cells by use of free radical scavengers greatly inhibited Con-A hepatitis without suppressing cytokine production. However, adoptive transfer experiments also indicate that a close interaction/cooperation of Kupffer cells with NKT cells is essential for Con-A hepatitis.. Superoxide produced by Kupffer cells may be the essential effector in Con-A hepatitis, and TNF and NKT cells support their activation and superoxide production.

Topics: Animals; Anti-Inflammatory Agents; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Cell Communication; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Gadolinium; Interferon-gamma; Killer Cells, Natural; Kupffer Cells; Male; Mice; Mice, Inbred C57BL; Reactive Oxygen Species; Superoxides; T-Lymphocytes; Tumor Necrosis Factor-alpha

The effect of Laennec, a hydrolyte of human placenta, on immune-mediated liver injury was investigated in vivo and in vitro in murine. Vena caudalis administration of concanavalin A (Con A) was employed to establish an in vivo liver-injury model, and in vitro hepatotoxicity was induced by 8 h interaction between Con A pre-treated hepatocytes and Con A-stimulated autologous splenic lymphocytes. Laennec was used for pre-treatment in the two models. Laennec decreased biochemical marker activity (alanine aminotransferase, ALT; lactate dehydrogenase, LDH) in serum and recovered the activity of superoxide dismutase (SOD) and myeloperoxidase (MPO), as well as the content of malondialdehyde (MDA) and nitric oxide (NO) in liver tissue. We also found that the DNA ladder induced by Con A in vivo was attenuated by Laennec. Furthermore, the leakage of aspartate aminotransferase (AST) and LDH in the supernatant of the co-culture system was decreased by addition of Laennec. Potential protective mechanisms were elucidated by DNA fragmentation assay and intercellular adhesion molecule-1 (ICAM-1) induction/inhibition experiments. Results showed that ICAM-1, which is related to the interaction between hepatocytes and lymphocytes, was inhibited by Laennec. These findings indicated that Laennec has potent activity against immune-mediated liver injury.

Topics: Animals; Apoptosis; Biomarkers; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytosol; DNA; Electrophoresis, Polyacrylamide Gel; Female; Hepatocytes; Immunohistochemistry; Intercellular Adhesion Molecule-1; Liver; Lymphocytes; Mice; Mice, Inbred BALB C; Placenta; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Spleen; Tissue Extracts

Th17 cells, a subset of T cells involved in autoimmunity and host defense against extracellular Gram-negative infection, express both IL-17A and IL-17F. Both IL-17A and IL-17F can signal via the IL-17RA; however, IL-17F does so at a 1- to 2-log higher concentration than IL-17A. In this study, we show that the IL-17F homodimer via IL-17RA is a negative regulator of IL-17 production in T cells and suggest a mechanism whereby IL-17RA on T cells serves as an autocrine/paracrine regulator of IL-17 synthesis in T cells.

Topics: Animals; Autocrine Communication; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Gram-Negative Bacterial Infections; Interleukin-17; Mice; Mice, Knockout; Mitogens; Paracrine Communication; Receptors, Interleukin-17; Signal Transduction

Two types of experimental liver failure in mice were investigated to study the immune mechanisms of liver disease: 1) T-cell-mediated injury induced by administration of concanavalin A (ConA) and 2) antibody-mediated injury induced by administration of anti-liver antibodies (ALA, gamma-globulin fraction of sera from rabbits immunized with liver tissue). It was established, that both types of liver injury were accompanied by the activation of immune processes in the liver, as shown by the increase of liver mononuclear cell proliferation, estimated using IPO-38 monoclonal antibodies. In contrast to ConA treatment, the immune activation under ALA-treatment was also associated with the increase in the percentage of plasma cells and small lymphocytes in liver mononuclear cells. At the same time, an increase in apoptotic and necrotic mononuclear cell death was more pronounced under ConA-treatment. This was accompanied by enhanced Fas receptor expression in these cells. Thus, it was shown that in case of T-cell mediated liver injury, the balance between cell proliferation and cell death in mononuclear liver cells was shifted toward the significant increase of apoptotic and necrotic cell death, particularly Fas-mediated apoptosis, while immune processes activation and cell proliferation were more pronounced in the case of antibodies-mediated injury.

Topics: Animals; Antibodies, Monoclonal; Apoptosis; Cell Death; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Hepatitis, Autoimmune; Leukocytes, Mononuclear; Liver; Male; Mice; Mice, Inbred CBA; T-Lymphocytes

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

The signals driving T cell activation in T cell-mediated fulminant hepatitis are not fully understood. In this study, we identify the cytokine IL-27p28/EBI3 as a major pathogenic factor in the ConA model of T cell-mediated hepatitis. We found an up-regulation of hepatic EBI3 and p28 expression and augmented levels of IL-27 in wild-type mice after ConA administration, suggesting a potential pathogenic role of this cytokine in ConA hepatitis. Consistently, IL-27 EBI3-deficient mice were almost completely protected from ConA-induced liver damage. Such protection was associated with reduced levels of IFN-gamma and its signaling proteins pSTAT-1 and T-bet. Finally, in vivo blockade of IL-27 function using a soluble IL-27 receptor fusion protein led to reduced pSTAT1 levels and suppression of liver injury. Taken together, these data demonstrate a key pathogenic role of IL-27 in T cell-mediated liver injury. Furthermore, in vivo blockade of IL-27 emerges as a novel potential therapy for T cell-mediated hepatitis.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-17; Mice; Mice, Knockout; Minor Histocompatibility Antigens; Receptors, Cytokine; Signal Transduction; STAT1 Transcription Factor; T-Lymphocytes; Up-Regulation

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

TNF-alpha, IFN-gamma, IL-4, and MIP-2 are known to be involved in Con A-induced hepatitis. Although Kupffer cells are reportedly involved in TNF-alpha production, it is largely unknown whether or not Kupffer cells also play a role in the production of other cytokines, such as IFN-gamma, IL-4, and MIP-2. In this study we examined the liver injury and the levels of plasma cytokines, including above four cytokines, KC, and IL-10 in Kupffer cell-depleted mice obtained through administration of liposome-encapsulated dichloromethylene bisphosphonate. The liver injury was significantly suppressed in Kupffer cell-depleted mice, as assessed as to the plasma ALT level and histochemistry. The cytokine levels were also significantly suppressed in such mice except for those of IFN-gamma, which was slightly suppressed at 12h, and IL-10, which was not significantly suppressed at any time. Apoptosis was also significantly suppressed in such mice, as found immunohistochemically with anti-ssDNA Ab. Taken together, these results suggest that Kupffer cells are involved in the production of MIP-2, KC, IL-4, and TNF-alpha in Con A-induced hepatitis, thereby contributing to the liver injury either directly or indirectly.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Clodronic Acid; Concanavalin A; Cytokines; Disease Models, Animal; Immunohistochemistry; Kupffer Cells; Liposomes; Male; Mice

Oxidative stress-mediated destruction of normal parenchymal cells during hepatic inflammatory responses contributes to the pathogenesis of immune-mediated hepatitis and is implicated in the progression of acute inflammatory liver injury to chronic inflammatory liver disease. The transcription factor NF-E2-related factor 2 (Nrf2) regulates the expression of a battery of antioxidative enzymes and Nrf2 signaling can be activated by small-molecule drugs that disrupt Keap1-mediated repression of Nrf2 signaling. Therefore, genetic and pharmacologic approaches were used to activate Nrf2 signaling to assess protection against inflammatory liver injury. Profound increases in indicators of cell death were observed in both Nrf2 wild-type (Nrf2-WT) mice and Nrf2-disrupted (Nrf2-KO) mice 24 h following intravenous injection of concanavalin A (12.5 mg/kg, ConA), a model for T cell-mediated acute inflammatory liver injury. However, hepatocyte-specific conditional Keap1 null (Alb-Cre:Keap1(flox/-), cKeap1-KO) mice with constitutively enhanced expression of Nrf2-regulated antioxidative genes as well as Nrf2-WT mice but not Nrf2-KO mice pretreated with three daily doses of a triterpenoid that potently activates Nrf2 (30 mumol/kg, cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl-imidazolide [CDDO-Im]) were highly resistant to ConA-mediated inflammatory liver injury. CDDO-Im pretreatment of both Nrf2-WT and Nrf2-KO mice resulted in equivalent suppression of serum proinflammatory soluble proteins suggesting that the hepatoprotection afforded by CDDO-Im pretreatment of Nrf2-WT mice but not Nrf2-KO mice was not due to suppression of systemic proinflammatory signaling, but instead was due to activation of Nrf2 signaling in the liver. Enhanced hepatic expression of Nrf2-regulated antioxidative genes inhibited inflammation-mediated oxidative stress, thereby preventing hepatocyte necrosis. Attenuation of hepatocyte death in cKeap1-KO mice and CDDO-Im pretreated Nrf2-WT mice resulted in decreased late-phase proinflammatory gene expression in the liver thereby diminishing the sustained influx of inflammatory cells initially stimulated by the ConA challenge. Taken together, these results clearly illustrate that targeted cytoprotection of hepatocytes through Nrf2 signaling during inflammation prevents the amplification of inflammatory responses in the liver.

Topics: Aconitate Hydratase; Adaptor Proteins, Signal Transducing; Alanine Transaminase; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Cytoskeletal Proteins; Female; Gene Expression Profiling; Hepatocytes; Imidazoles; Kelch-Like ECH-Associated Protein 1; Lipid Peroxidation; Liver; Male; Mice; Mice, Knockout; NF-E2-Related Factor 2; Oleanolic Acid; Signal Transduction

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

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

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

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

The liver appears to play an important role in immunological tolerance, for example, during allo-transplantation. We investigated tolerance mechanisms in the model of concanavalin A (ConA)-induced immune-mediated liver injury in mice. We found that a single injection of a sublethal ConA dose to C57BL/6 mice induced tolerance toward ConA-induced liver damage within 8 days. This tolerogenic state was characterized by suppression of the typical Th1 response in this model and increased IL-10 production. Tolerance induction was fully reversible in IL-10 -/- mice and after blockade of IL-10 responses by anti-IL10R antibody. Co-cultures of CD4+CD25+ regulatory T cells (T(reg)s) and CD4+CD25- responder cells revealed T(reg) from ConA-tolerant mice being more effective in suppressing polyclonal T cell responses than T(reg) from control mice. Moreover, T(reg) from tolerant but not from control mice were able to augment in vitro IL-10 expression. Depletion by anti-CD25 monoclonal antibody (MAb) indicated a functional role of T(reg)s in ConA tolerance in vivo. Cell depletion studies revealed T(reg)S and Kupffer cells (KC) to be crucial for IL-10 expression in ConA tolerance. Studies with CD1d -/- mice lacking natural killer T (NKT) cells disclosed these cells as irrelevant for the tolerogenic effect. Finally, cellular immune therapy with CD4+CD25+ cells prevented ConA-induced liver injury, with higher protection by Treg from ConA-tolerized mice.. The immunosuppressive cytokine IL-10 is crucial for tolerance induction in ConA hepatitis and is mainly expressed by CD4+CD25+ T(reg) and KC. Moreover, T(reg)s exhibit therapeutic potential against immune-mediated liver injury.

Topics: Animals; CD4 Antigens; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Tolerance; Interleukin-10; Interleukin-2; Interleukin-2 Receptor alpha Subunit; Kupffer Cells; Liver; Male; Mice; Mice, Knockout; Mitogens; RNA, Messenger; T-Lymphocytes, Regulatory

Prevention of hepatitis is a worldwide issue. For most patients with liver disease, hepatoprotective drugs are required. But there are only a few hepatoprotective drugs available. Osthole is a coumarin compound and protects the liver from hepatitis by preventing the development of apoptosis. However, osthole exhibits low water solubility, and some structural modifications are required for sufficient hepatoprotection upon oral administration. We synthesized 28 osthole derivatives, and then studied their effects by using mice concanavalin A (Con A) -induced hepatitis. The osthole derivatives No.1, 9 and 19 showed stronger inhibition of Con A-induced elevation of plasma alanine aminotransferase (ALT). Oral administration of osthole at the dose of 100 mg/kg (n=10) inhibited 38.0% of the Con A-induced elevation of plasma ALT. In contrast, oral administration of Nos. 1, 9 and 19 at the dose of 100 mg/kg (n=5) caused 68.7%, 62.5% and 88.3% inhibition of the Con A-induced elevation of plasma ALT, respectively. These synthetic osthole derivatives could contribute to the development of hepatoprotective drugs effective for various types of liver diseases on oral administration.

Topics: Alanine Transaminase; Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Coumarins; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Female; Indicators and Reagents; Mice; Mice, Inbred BALB C; T-Lymphocytes

Baicalin (BA) exhibits an anti-inflammatory effect in vivo and in vitro and is used to treat chronic hepatitis. However, the mechanism by which BA exerts the liver-protective effect remains largely unknown.. The present study reports that BA inhibits cytokine production and hepatocyte apoptosis to protect mice from liver injury induced by concanavalin A (Con A), a T-cell-dependent liver injury model.. Con A injection of mice induced severe immune responses and extensive hepatocellular apoptosis within 24 h. Pretreatment of 200 or 100 mg/kg BA markedly reduced serum aminotransferase activities, protected hepatoycte apoptosis and reduced the increase of plasma cytokine levels, including tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin-6 (IL-6). Furthermore, BA pretreatment decreased tissue myeloperoxidase activity and lipid peroxidation, but increased the superoxide dismutase level. In vitro studies indicated that the beneficial effect of BA was associated with reduced cytokine production from lymphocytes and reduced TNF-alpha-induced hepatocyte apoptosis.. These results suggest that BA has therapeutic potential for T-cell-mediated liver injury.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Flavonoids; Hepatocytes; Mice; Mice, Inbred Strains; Protective Agents; T-Lymphocytes; Treatment Outcome; Tumor Necrosis Factor-alpha

To explore the gene expressions of LTC4 synthase homologs in concanavalin A (Con A)-induced mouse hepatitis and regulation role of cyclosporine A (Cs A) treatment.. Male Balb/c mouse liver injury model was developed by iv injection of Con A (20 mg/kg) and protected by Cs A pretreatment (150 mg/kg) before Con A administration. Blood samples were collected at indicated times after Con A treatment with or without Cs A pretreatment. Liver damage was assessed by serum transaminase ALT and AST measurement and histological evaluation. Meantime, three LTC4 synthase homolog gene expressions were determined by RT-PCR.. Serum ALT and AST upregulation were accompanied with histological damage at 2 h after Con A administration, and further aggravated at 8 h. mGST2 gene expression increased 1.7 fold at 2 h and 1.9 fold at 8 h, while the expression of LTC4 S and mGST3 changed little. Pretreatment with Cs A prevented mouse liver from injury by Con A and partly inhibited the mGST2 gene expression upregulation.. Administration of Con A in mouse lead to a significant increase of mGST2 gene expression without any significant effect on LTC4 S and mGST3 mRNA levels. Cs A pretreatment results in protection of liver damage, whereas fails to fully inhibit the increase of mGST2 gene expression.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclosporine; Gene Expression Regulation, Enzymologic; Glutathione Transferase; Hepatitis, Animal; Immunosuppressive Agents; Injections, Intravenous; Isoenzymes; Male; Mice; Mice, Inbred BALB C; Reverse Transcriptase Polymerase Chain Reaction

The innate immunopathogenesis responsible for the susceptibility to hepatocyte injury in chronic hepatitis B surface antigen carriers is not well defined. In this study, hepatitis B virus (HBV) transgenic mice (named HBs-Tg) were oversensitive to liver injury after immunologic [polyinosinic:polycytidylic acid or concanavalin A (ConA)] or chemical (CCl4) triggering. It was then found that the nonhepatotoxic low dose of ConA for wild-type mice induced severe liver injury in HBs-Tg mice, which was dependent on the accumulated intraheptic natural killer (NK) cells. Expressions of NKG2D ligands (Rae-1 and Mult-1) in hepatocytes were markedly enhanced upon ConA stimulation in HBs-Tg mice, which greatly activated hepatic NK cells via NKG2D/Rae-1 or Mult-1 recognition. Interestingly, the presence of NK T cells was necessary for NK cell activation and worked as positive helper cell possibly by producing interferon-gamma and interleukin-4 in this process.. Our findings for the first time suggested the critical role of NKG2D recognition of hepatocytes by NK cells in oversensitive liver injury during chronic HBV infection.

Topics: Animals; Carbon Tetrachloride; Carrier Proteins; Carrier State; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Susceptibility; Hepatitis B Surface Antigens; Hepatitis B virus; Histocompatibility Antigens Class I; Killer Cells, Natural; Ligands; Liver; Membrane Proteins; Mice; Mice, Transgenic; NK Cell Lectin-Like Receptor Subfamily K; Nuclear Matrix-Associated Proteins; Nucleocytoplasmic Transport Proteins; Receptors, Immunologic; Receptors, Natural Killer Cell

Analysis of the molecular factors determining hepatocyte survival or death in response to inflammatory stimuli is essential for understanding the pathogenesis of inflammatory liver disease and for identifying novel therapeutic approaches. c-Jun N-terminal kinase (JNK) is a major mediator of cytokine-induced cell death during hepatitis, but the signaling pathways downstream of JNK remain less well defined. Here we show that the transcription factor c-Jun/AP-1, a prototypic target of JNK, is strongly expressed in the liver of patients with acute liver injury. The molecular function of c-Jun in inflammatory liver disease was analyzed in mice by using the Con A model of T cell-mediated hepatitis. Mice lacking c-Jun in hepatocytes display increased liver cell death and mortality upon Con A injection. This phenotype is caused by impaired expression of inducible nitric oxide synthase (nos2), a direct transcriptional target of c-Jun, and reduced production of hepatoprotective nitric oxide (NO). Moreover, increased hepatotoxicity in mutant mice is likely caused by hypoxia and oxidative stress and can be rescued pharmacologically by liver-specific NO delivery. These findings demonstrate that c-Jun/AP-1 is hepatoprotective during acute hepatitis by regulating nos2/NO expression and thus functionally antagonizes the cell death-promoting functions of JNK.

Topics: Animals; Cell Death; Cell Hypoxia; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; Gene Expression Regulation, Enzymologic; Hepatitis; Hepatocytes; Humans; JNK Mitogen-Activated Protein Kinases; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Proto-Oncogene Proteins c-jun; Transcription, Genetic; Tumor Suppressor Protein p53

Topics: Animals; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Interleukin-2 Receptor alpha Subunit; Male; Mice; Mice, Inbred Strains; Tumor Necrosis Factor Receptor Superfamily, Member 9

Osteopontin (OPN) has been implicated in various helper T cell type 1 immunity-mediated diseases including rheumatoid arthritis (RA), multiple sclerosis (MS), Crohn's disease, and fulminant hepatitis. Increased expression of OPN has been detected in pathological foci of these diseases. RA and fulminant hepatitis have been successfully treated by administration of neutralizing anti-OPN antibody in mice. Antibody treatment may elicit side effects including allergic reactions against heterologous antibody proteins, thus necessitating humanization of antibody. To provide alternative means to neutralize OPN function, in this study we explored the possibility of using OPN small interfering RNA (siRNA) to silence OPN gene expression. In vitro, OPN siRNA efficiently silenced the expression of both exogenous and endogenous OPN gene. After hydrodynamic intravenous injection of OPN siRNA, OPN siRNA was efficiently delivered to the liver, which resulted in the efficient silencing of OPN gene expression in liver. In a murine model of concanavalin A (ConA)-induced fulminant hepatitis, OPN expression was elevated in liver and severe hepatic necrosis was induced. Importantly, after OPN siRNA treatment, the OPN expression level in liver was significantly reduced and liver tissue injury was ameliorated, as reflected by the significant reduction of serum alanine aminotransferase levels and almost normal liver histology. Thus, this study indicates that OPN siRNA delivery has therapeutic potential in various inflammatory diseases in which OPN play a critical role by silencing OPN gene expression in vivo.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Genetic Therapy; Liver; Liver Failure, Acute; Mice; Mice, Inbred C57BL; Osteopontin; RNA Interference; RNA, Small Interfering; Transfection

Concanavalin A (Con A)-induced hepatitis is a model for human T cell-mediated hepatitis. We evaluated the role of L-selectin and intercellular adhesion molecule-1 (ICAM-1) in this model by injecting Con A intravenously in mice lacking L-selectin (L-selectin-/-), ICAM-1 (ICAM-1-/-), or both (L-selectin/ICAM-1-/-). Blood and liver samples were collected 0, 8, 24, and 48 h after Con A treatment. Increases in plasma transaminase levels, which peaked 8 h after injection, were reduced significantly in L-selectin-/-, ICAM-1-/-, and L-selectin/ICAM-1-/- mice compared with wild-type mice. Liver necrosis was more strongly inhibited in ICAM-1-/- mice than in L-selectin-/- mice but was most prominently reduced in L-selectin/ICAM-1-/- mice, in parallel with decreased plasma transaminase levels. The reduced severity of hepatitis in the mutant mice correlated with decreases in numbers of liver CD4+ T cells but not numbers of CD8+ T cells or neutrophils. Following Con A treatment, L-selectin deficiency reduced liver mRNA expression of tumor necrosis factor-alpha, and ICAM-1 deficiency reduced expression of interleukin-4. By contrast, reductions in liver macrophage inhibitor protein-1alpha mRNA occurred in all mutant mice. These results indicate that L-selectin and ICAM-1 contribute cooperatively to the development of Con A-induced hepatitis by regulating leukocyte infiltration and subsequent cytokine production.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Intercellular Adhesion Molecule-1; L-Selectin; Leukocytes; Liver; Mice; Mice, Knockout; RNA, Messenger; Time Factors; Transforming Growth Factors

To evaluate hepatoprotective effect of alpha-calcitonin gene-related peptide (alphaCGRP), we compared the susceptibilities of alphaCGRP-/- and wild-type mice to concanavalin A (Con A)-induced hepatitis. Twelve hours after Con A administration, serum transaminases were markedly higher in alphaCGRP-/- than wild-type mice, and much more extensive TUNEL-positive lesions and DNA fragmentation were detected in the livers of alphaCGRP-/- mice. Notably, expression of IL-6 was selectively diminished in alphaCGRP-/- mice, suggesting that induction of IL-6 during acute inflammatory responses is blunted in alphaCGRP-/- mice. In addition, primary cultured alphaCGRP-/- hepatocytes were more susceptible to IFN-gamma-induced cell death than hepatocytes from wild-type mice. Administration of exogenous alphaCGRP reduced the incidence of apoptosis among hepatocytes and endothelial cells. It thus appears that alphaCGRP exerts a hepatoprotective effect by modulating cytokine expression and preventing apoptosis.

Topics: Alanine Transaminase; Animals; Apoptosis; Calcitonin Gene-Related Peptide; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; DNA Fragmentation; Hepatocytes; Interferon-gamma; Liver; Male; Mice; Mice, Knockout

Topics: Animals; Anti-Retroviral Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Humans; Mice; Mice, Knockout; Receptors, CCR5; T-Lymphocytes

The mechanism(s) that regulates NK cell mobilization and the significance of this process to NK cell activity are unknown. After Con A-induced hepatitis, NK cells are mobilized from the spleen and bone marrow into the periphery in an IFN-gamma-dependent fashion. Intraperitoneal administration of IFN-gamma stimulates the mobilization of NK cells into the circulation, but not their cell death or proliferation. Increased number of circulating NK cells was coupled with their accumulation in the peritoneum, liver, and tumor-bearing lung tissue. Furthermore, increased number of NK cells in the lung reduced metastasis of Lewis lung carcinoma cells (3LL cell line) resulting in significantly extended NK-dependent survival. Mobilization of NK cells was specific and required the presence of T cells. Moreover, mobilization and migration of spleen NK cells in response to IFN-gamma treatment is dependent on the chemokine receptor CXCR3. Mechanistic insights regarding the role of IFN-gamma in the regulation of NK cell mobilization and their accumulation at sites of tumor metastasis may lead to the development of novel immunotherapy for cancer.

Topics: Adoptive Transfer; Animals; Bone Marrow; Carcinoma, Lewis Lung; Cell Communication; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Chemokine CXCL9; Chemokines, CXC; Concanavalin A; In Vitro Techniques; Interferon-gamma; Killer Cells, Natural; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptors, Chemokine; Receptors, CXCR3; Recombinant Proteins; Spleen; T-Lymphocytes

(5R)-5-hydroxytriptolide (LLDT-8) exhibits strong immunosuppressive activities in vitro and in vivo. Here, we investigated the effects of LLDT-8 on concanavalin A-induced hepatitis. Liver damage was evaluated by serum alanine transaminase (ALT) level and liver histology. The effects of LLDT-8 were determined by measurement of serum cytokines, lymphocyte proliferation assay, flow cytometry analysis of splenic T cell percentage and apoptosis, reverse-transcription polymerase chain reaction (RT-PCR) analysis for gene transcriptions. In LLDT-8-treated mice, serum ALT level and histological damage were markedly attenuated. The beneficial effect of LLDT-8 was closely associated with (i) reduction of serum tumor necrosis factor-alpha, interferon-gamma (IFN-gamma), interleukin-2, interleukin-12, and interleukin-6 levels; (ii) elimination of activated T cells by increasing proapoptotic genes signal transducer and activator of transcription 1 (STAT1) and interferon regulatory factor-1 (IRF-1) expression in spleens; (iii) blockade of mRNA expressions for chemokines (monokine induced by IFN-gamma, Mig; IFN-gamma-inducible protein-10, IP-10; IFN-inducible T cell-alpha chemoattractant, I-TAC), vascular adhesion molecule-1 (VCAM-1), and chemokine receptors (C-C chemokine receptor 1, CCR1; C-C chemokine receptor 5, CCR5; C-X-C chemokine receptor 3, CXCR3) in livers. These results suggested the therapeutic potential of LLDT-8 in IFN-gamma/STAT1/IRF-1 signaling- and inflammatory cytokines-mediated immune disorders.

Topics: Alanine Transaminase; Animals; Apoptosis; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Diterpenes; Female; Gene Expression Regulation; Immunosuppressive Agents; Interferon Regulatory Factor-1; Interferon-gamma; Mice; Mice, Inbred BALB C; RNA, Messenger; Spleen; STAT1 Transcription Factor; T-Lymphocytes

To identify potent and selective calcium-release-activated calcium (CRAC) channel inhibitors, we examined the structure-activity relationships of the pyrazole and thiophene moieties in compound 4. Compound 25b was found to exhibit highly potent and selective inhibitory activity for CRAC channels and further modifications of the pyrazole and benzoyl moieties of compound 25b produced compound 29. These compounds were potent inhibitors of IL-2 production in vitro and also acted as inhibitors in pharmacological models of diseases resulting from T-lymphocyte activation, after oral administration.

Topics: Animals; Calcium; Calcium Channel Blockers; Calcium Channels; Cell Line, Tumor; Chemical and Drug Induced Liver Injury; Concanavalin A; Crystallography, X-Ray; Disease Models, Animal; Drug Evaluation, Preclinical; Female; Humans; Hypersensitivity; Jurkat Cells; Male; Mice; Mice, Inbred BALB C; Models, Molecular; Molecular Structure; Picryl Chloride; Pyrazoles; Stereoisomerism; Structure-Activity Relationship

In traditional oriental medicine, Yin-Chen-Hao decoction is used for the remedy of liver diseases such as hepatitis, fatty liver, hepatocirrhosis and jaundice. However, despite extensive pharmacological study, the molecular mechanism of the anti-inflammatory effect of Yin-Chen-Hao decoction is poorly understood. In this study, we have investigated the pharmacological action on the mechanism of concanavalin A-induced T cell-dependent hepatitis in mice. Concanavalin A administration resulted in a severe liver injury. This was shown through increased levels of serum transaminase and lactic dehydrogenase, and increased liver DNA fragmentation and caspase-3 activity. Pretreatment with the aqueous extract from Yin-Chen-Hao decoction dose-dependently inhibited the elevation in transaminase and lactic dehydrogenase activity, and reduced liver DNA fragmentation and caspase-3 levels. There was an improvement in histological changes including inflammatory infiltration, hepatocyte necrosis and degeneration, and Kupffer cell hyperplasia. In addition, Yin-Chen-Hao decoction significantly inhibited tumour necrosis factor-alpha (TNF-alpha) production in-vitro and in-vivo. Moreover, the activation of nuclear factor kappa B (NF-kappaB), which regulates TNF-alpha production, was blocked by Yin-Chen-Hao decoction in-vitro and in-vivo. In conclusion, Yin-Chen-Hao decoction was capable of regulating T-cell-mediated liver injury in-vivo. This event may have depended on the decrease of TNF-alpha production through the inhibition of NF-kappaB activation.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Apoptosis; Artemisia; Aspartate Aminotransferases; Caspase 3; Caspases; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Gardenia; L-Lactate Dehydrogenase; Liver; Lymphocytes; Mice; Mice, Inbred ICR; NF-kappa B; Rheum; Time Factors; Tumor Necrosis Factor-alpha

T cell-mediated immune responses play a critical role in a variety of liver injuries including autoimmune hepatitis. Injection of concanavalin A (Con A) into mice mimics the histological and pathological phenotype of T cell-mediated hepatitis. Recent advances in host immune control of organ transplantation include the development of sphingosine-1-phosphate (S1P) receptor agonists such as FTY720, which alter lymphocyte homing but do not suppress host general immunity. Herein we examined the effect of the new S1P receptor agonist KRP-203 on the Con A-induced liver damage model. In normal liver lymphocytes of BALB/c mice, both FTY720 and KRP203 promoted lymphocyte sequestering from the liver to secondary lymph nodes and significantly reduced the number of liver lymphocytes (p<0.05). Based on this observation, KRP203 was employed in the Con A-induced hepatitis model. KRP203 markedly reduced the number of CD4(+) lymphocytes that infiltrate Con A-treated liver (p<0.05) and successfully reduced serum transaminase elevation (p=0.017), therefore protecting mice from Con A-induced liver injury. Interestingly this homing modulation less occurs in natural hepatic T cell homing through the chemokine receptor, CXCR4. Therefore, S1P receptor agonists preferentially target CXCR4(+)CD4(+) peripheral blood T lymphocytes and suppress the occurrence of Con A-induced hepatitis, suggesting their therapeutic usefulness against T cell-mediated hepatic injury.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Fingolimod Hydrochloride; Liver; Lymphocytes; Male; Mice; Mice, Inbred BALB C; Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine; Sulfhydryl Compounds; Treatment Outcome

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

Administration of concanavalin A (Con A) induces a rapid and severe liver injury in mice. Natural killer T (NKT) cells are recognized to be the key effector cells, and a variety of cytokines [e.g., interleukin 4 (IL-4), IL-5, interferon gamma (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha)] have been shown to play vital roles in Con A-induced liver injury, whereas the role of IL-15, a critical cytokine in the development and homeostasis of NKT cells, remains obscure. In this study, pretreatment with IL-15 prevented mice from Con A-induced mortality, elevation of serum transaminase, liver necrosis, and hepatocyte apoptosis. Depletion of NKT cells abolished Con A-induced liver injury, which could be restored by adoptive transfer of purified NKT cells but not by that of in vivo or in vitro IL-15-treated hepatic NKT cells. Furthermore, transfer of wild-type NKT cells to CD1d-/- mice restored liver injury, whereas transfer of IL-15-treated NKT cells did not. IL-15 pretreatment decreased the NKT-derived IL-4, IL-5, and TNF-alpha production, thereby resulting in less infiltration of eosinophils, which play a critical role in Con A-induced liver injury. In conclusion, IL-15 protects against Con A-induced liver injury via an NKT cell-dependent mechanism by reducing their production of IL-4, IL-5, and infiltration of eosinophils. These findings suggest that IL-15 may be of therapeutic relevance in human autoimmune-related hepatitis.

Topics: Animals; Biopsy, Needle; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Disease Models, Animal; Immunohistochemistry; In Situ Nick-End Labeling; Inflammation Mediators; Interleukin-15; Killer Cells, Natural; Liver Function Tests; Male; Mice; Mice, Inbred C57BL; Probability; Reference Values; Sensitivity and Specificity

Steatohepatitis enhances the severity of liver injury caused by acute inflammation. The purpose of this study was to test the hypothesis that fatty liver due to chronic choline-deficient diet exacerbates concanavalin A (ConA)-induced liver hepatitis, which is predominantly facilitated by T cells. Male C57BL/6 mice were fed either control choline-sufficient diet (CSD) or choline-deficient diet (CDD) for 6 weeks before ConA administration. Mice were sacrificed 3, 9, and 24 hours after ConA injection. Liver injury measured by aspartate aminotransferase (AST), alanine aminotransferase (ALT), pathology, and terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) staining was minimal in mice fed either diet before ConA exposure. However, ConA-induced liver injury was significantly greater in CDD-fed mice compared with control-fed mice. Liver cytokines were assessed by quantitative real-time polymerase chain reaction (PCR). The expression of T helper (Th) 1 cytokines tumor necrosis factor alpha (TNF-alpha), interleukin 12 (IL-12), and interferon gamma (IFN-gamma) were dramatically elevated after ConA in CDD-fed mice compared with control-fed mice. CDD also enhanced ConA-induced STAT4 activation, but not STAT6. Notably, regulators of T-cell differentiation were strongly shifted toward a predominant Th1 profile. T-bet, regulator of the Th1 response, was up-regulated in CDD-fed mice, whereas Th2 regulator GATA-3 was significantly suppressed in CDD-fed mice after ConA. Moreover, the expression of suppressor of cytokine signaling (SOCS)-1, SOCS-3, and repressor of GATA-3 (ROG) favored a predominant Th1 cytokine response in CDD-fed mice. In conclusion, these data support the hypothesis that hepatosteatosis caused by CDD is associated with more severe ConA-induced hepatitis due to a predominant shift toward Th1 response.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Blotting, Western; Cell Differentiation; Chemical and Drug Induced Liver Injury; Choline Deficiency; Concanavalin A; Cytokines; Disease Models, Animal; Disease Progression; Fatty Liver; GATA3 Transcription Factor; Gene Expression; Male; Mice; Mice, Inbred C57BL; Polymerase Chain Reaction; RNA, Messenger; T-Box Domain Proteins; T-Lymphocytes; Th1 Cells; Transcription Factors

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

A recent study has suggested that the methylation silencing of the suppressor of cytokine signaling-3 (SOCS3), a negative regulator of interleukin-6-related cytokines, could be involved in hepatocellular carcinoma (HCC). However, the roles of SOCS3 in hepatocellular carcinogenesis and hepatitis have not been established. We investigated the effect of deleting the SOCS3 gene on the development of hepatitis and HCC in hepatitis C virus-infected patients and mouse models.. The expression of SOCS genes in HCC and non-HCC regions of patient samples was determined by real-time reverse-transcription polymerase chain reaction and immunoblotting. The conditional knockout approach in mice was used to determine the hepatocyte-specific roles of SOCS3. To generate a liver-specific deletion, floxed SOCS3 (SOCS3(fl/fl)) mice were crossed with albumin-Cre transgenic mice. Hepatitis and HCC were induced by administering concanavalin A and diethylnitrosamine, respectively.. SOCS3 expression was reduced in the HCC regions compared with the non-HCC regions. Carcinogen-induced hepatic tumor development was enhanced by deletion of the SOCS3 gene, which was associated with higher levels of the targets of signal transducers and activators of transcription (ie, B-cell lymphoma-XL, B-cell lymphoma-2, C-myelocytomatosis, cyclin D1, and vascular endothelial growth factor). In the concanavalin A-mediated hepatitis model, deletion of the SOCS3 gene in the hepatocytes protected against liver injury through suppression of interferon-gamma signaling and induction of the antiapoptotic protein Bcl-XL.. Deletion of the SOCS3 gene in hepatocytes promotes the activation of STAT3, resistance to apoptosis, and an acceleration of proliferation, resulting in enhanced hepatitis-induced hepatocarcinogenesis.

Topics: Adult; Aged; Animals; Carcinoma, Hepatocellular; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Gene Deletion; Hepatocytes; Humans; Immunohistochemistry; In Vitro Techniques; Liver Neoplasms; Male; Mice; Middle Aged; Reverse Transcriptase Polymerase Chain Reaction; RNA, Neoplasm; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins

(-)-Epigallocatechin-3-gallate (EGCG) is the major active component of green tea. Increasing evidence has suggested that EGCG exhibits anti-inflammatory, anti-oxidant and immunosuppressive effects. In this study, we investigated the effect of EGCG on concanavalin A (ConA)-induced hepatitis (CIH) in mice, a model of immune-mediated liver injury in humans. We pretreated mice with EGCG before ConA injection, and then measured alanine aminotransferase (ALT) levels in plasma, inflammatory infiltration and hepatocyte apoptosis in liver. Potential therapeutic mechanisms were elucidated further by measuring several inflammatory mediators. Mice pretreated with EGCG exhibited much less increased ALT levels in plasma, reduced inflammatory infiltration and hepatocyte apoptosis in liver compared with control mice pretreated with vehicle solutions. We further investigated the mechanisms of the protective effects of EGCG. In EGCG-pretreated mice, we found abrogated tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma at both protein levels in plasma and mRNA levels in liver. At the same time, the concentration of nitrite in plasma and inducible nitric oxide synthase production in liver were both down-regulated in these mice. Moreover, IFN-inducible protein-10 and macrophage inflammatory protein-1alpha expressions in liver were decreased significantly. Therefore, EGCG is capable of regulating immune-mediated liver injury in vivo. The protective effect depended on its suppressive effect on the production of important inflammatory mediators.

Topics: Alanine Transaminase; Animals; Apoptosis; Catechin; Chemical and Drug Induced Liver Injury; Chemokine CCL4; Chemokine CXCL10; Chemokines, CXC; Concanavalin A; Hepatocytes; Immunohistochemistry; Interferon-gamma; Liver; Macrophage Inflammatory Proteins; Male; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II; Nitrites; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha

Concanavalin A (Con A)-induced hepatitis has been investigated as a model of T cell-mediated liver injury, in which IFN-gamma plays an essential role by inducing apoptosis of liver cells. Since a large number of neutrophils infiltrate into the liver in the model, the role of neutrophils was investigated in this study. Con A hardly caused liver injury in neutrophil-depleted mice, as assessed as to the plasma alanine aminotransferase level as well as histochemistry. Neutrophil-depleted mice also failed to produce IFN-gamma. Intracellular IFN-gamma staining revealed that, among liver leukocytes, T and NK cells but not neutrophils are the main producers of IFN-gamma. Nylon wool-purified "T cells", however, failed to produce IFN-gamma in response to Con A in vitro, while the production was restored by the addition of neutrophils. Overall, this study suggests that neutrophils play a novel accessory role in IFN-gamma production in Con A-induced hepatitis.

Topics: Alanine Transaminase; Animals; CD8-Positive T-Lymphocytes; Cell Movement; Chemical and Drug Induced Liver Injury; Coculture Techniques; Concanavalin A; Disease Models, Animal; Interferon-gamma; Interleukin-4; Killer Cells, Natural; Leukocyte Reduction Procedures; Leukocytes; Liver; Male; Mice; Mice, Inbred C3H; Neutrophils; T-Lymphocytes; Tumor Necrosis Factor-alpha

Concanavalin A (ConA) induces natural killer T (NKT) cell-mediated liver damage. Glucocerebroside (GC) is a naturally occurring glycolipid. Our aims were to determine the effect of GC in a murine model of ConA-induced hepatitis. Mice in groups A and B were treated with GC 2 h before and 2 h following administration of ConA, respectively; group C mice were treated with ConA; group D mice was treated with GC; group E mice did not receive any treatment. Liver damage was evaluated by serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and liver histology. The immune effect of GC was determined by fluorescence-activated cell sorter analysis of intrahepatic and intrasplenic NKT lymphocytes, measurement of cytokine levels, and Western blot analysis for STAT 1, 4, 6, and NF-kappaB expression. The effect of GC on NKT cell proliferation was assessed in vitro. Serum AST and ALT levels were markedly reduced in GC-treated group A mice compared with nontreated group C animals, and histological damage was markedly attenuated in group A. The beneficial effect of GC was associated with a 20% decrease of intrahepatic NKT lymphocytes, significant lowering of serum IFN-gamma levels, and decreased STAT1 and STAT6 expression. In vitro administration of GC led to a 42% decrease of NKT cell proliferation in the presence of dendritic cells but not in their absence. Intraperitoneally administered radioactive GC was detected in the liver and bowel. Administration of GC led to amelioration of ConA hepatitis associated with an inhibitory effect on NKT lymphocytes. GC holds promise as a new immune-modulatory agent.

Topics: Animals; Cell Proliferation; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Dendritic Cells; Gene Expression; Glucosylceramides; Killer Cells, Natural; Liver; Male; Mice; Mice, Inbred BALB C; Spleen; T-Lymphocytes; Transcription Factors

Diphenyl dimethyl bicarboxylate (DDB) is a hepatoprotectant and used in the treatment of chronic viral hepatitis patients in China. The aim of the present paper was to investigate the effect of DDB on liver injury mediated by immune response in concanavalin A (Con A)-treated mice. A dose of Con A 30 mg/kg was injected via the tailvein to induce liver injury in mice. Serum alanine transaminase (ALT), aspartate aminotransferase (AST), total bile acid (TBA), total bilirubin (TBIL) and tumor necrosis factor alpha (TNF-alpha) level as well as liver TNF-alpha mRNA expression were determined. The following results were obtained: (1) Prior oral administration of DDB 150 mg/kg markedly reduced the elevated serum ALT, TBA and TBIL levels, and the liver lesions in Con A-treated mice; (2) DDB significantly inhibited the elevation of serum TNF-alpha and liver TNF-alpha mRNA expression 2 h after Con A injection; (3) DDB significantly inhibited hepatocyte nuclear DNA fragmentation 12 h after Con A injection; (4) DDB dose-dependently prevented the direct DNA damage induced by CuSO(4)-Phen-Vit C-H(2)O(2) system in vitro, and the ex vivo experiment also showed that the administration of DDB reduced the susceptibility of mouse liver nuclei DNA to CuSO(4)-Phen-Vit C-H(2)O(2) system. These results suggest that DDB could directly protect hepatocyte DNA from oxidative damage, and inhibit TNF-alpha mRNA expression in liver tissue, which resulted in prevention of liver damage induced by Con A in mice.

Topics: Adjuvants, Immunologic; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Dioxoles; Disease Models, Animal; DNA Damage; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Gene Expression; Hepatitis, Animal; Hepatocytes; Liver; Liver Function Tests; Male; Mice; Mice, Inbred ICR; Protective Agents; RNA, Messenger; Tumor Necrosis Factor-alpha

To assess the suitability of concanavalin-A-induced hepatitis as a model for investigating the relationships between hepatic disease and alterations in somnolence.. We characterized the sleep patterns of various strains of inbred mice undergoing ConA-induced inflammation.. Southern Illinois University School of Medicine, Springfield, IL.. Intravenous or intraperitoneal administration of concanavalin-A.. Inbred mice.. Intravenous and intraperitoneal administration of concanavalin-A both elicited strain-dependent changes in slow-wave sleep. ConA treatment also reduced spontaneous locomotor activity. ConA-induced changes in slow-wave sleep varied with dose, route of administration, and circadian period of administration. As compared with the other strains, C57BL/6J mice had lower serum concentrations of interferon-gamma at 8 hours after ConA administration.. These data provide the first demonstration that sleep enhancement and reduced locomotor activity accompany hepatic inflammation in mice.

Topics: Animals; Body Temperature; Chemical and Drug Induced Liver Injury; Concanavalin A; Injections, Intravenous; Interferon-gamma; Interleukin-6; Locomotion; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Peritonitis; Sleep, REM; Tumor Necrosis Factor-alpha

Imatinib exerts potent antileukemic effects in vitro and in vivo. Despite its well known antitumor activity, the potential of imatinib for the treatment of inflammatory diseases remains elusive so far. Our current report provides strong evidence that imatinib has potent antiinflammatory effects. It potently inhibits LPS- and Con A-induced TNF-alpha production by human myeloid cells in vitro (peripheral blood mononuclear cells, CD14-selected monocytes, and monocyte-derived macrophages). Of note, the production of the antiinflammatory cytokine IL-10 was not significantly regulated by imatinib. In line with this observation, phosphorylation of IkappaB and subsequent DNA binding of NF-kappaB, which is critically involved in TNF-alpha, but not IL-10 expression, was reduced by imatinib. Using several murine models of acute hepatitis, we could corroborate our in vitro findings, as imatinib prevented macrophage- and TNF-alpha-dependent inflammatory damage of the liver induced by injection of either Con A or d-galactosamine/LPS by inhibition of hepatic TNF-alpha production. Of note, d-galactosamine/TNF-induced hepatitis was not affected, showing that imatinib does not directly inhibit TNF-alpha-induced hepatocellular cell death. These findings suggest a potent antiinflammatory role of imatinib by modulation of TNF-alpha production in monocytes/macrophages. This observation might be of therapeutic value for the treatment of TNF-mediated diseases.

Topics: Animals; Benzamides; Cell Death; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Hepatitis, Animal; Humans; I-kappa B Proteins; Imatinib Mesylate; Inflammation; Interleukin-10; Lipopolysaccharides; Macrophages; NF-kappa B; Phosphorylation; Piperazines; Protein Kinase Inhibitors; Pyrimidines; Tumor Necrosis Factor-alpha

Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of different cytokines and chemokines and is characterized by leukocyte infiltration. Because the chemokine receptor CCR5 and its ligands (CCL3, CCL4, and CCL5) regulate leukocyte chemotaxis and activation, we investigated the role of CCR5 during Con A-induced liver injury. Serum levels of CCR5 ligands and their hepatic transcript levels were significantly increased after Con A injection, whereas CCR5+ liver mononuclear cells were recruited to the liver. CCR5-deficient (CCR5-/-) mice disclosed increased mortality and liver injury following Con A administration compared with wild-type mice. CCR5-/- mice also exhibited increased production of interleukin 4, tumor necrosis factor alpha, CCL3, CCL4, and CCL5, and a prominent liver mononuclear cell infiltrate, among which many cells were CCR1+. In vivo neutralization of CCR5 ligands in CCR5-/- mice afforded a protection against hepatitis only when CCL5 was neutralized. In conclusion, CCR5 deficiency exacerbates T-cell-mediated hepatitis, and leads to increased levels of CCR5 ligands and a more pronounced liver mononuclear infiltrate, suggesting that CCR5 expression can modulate severity of immuno-mediated liver injury.

Topics: Animals; Chemical and Drug Induced Liver Injury; Chemokine CCL3; Chemokine CCL4; Chemokines, CC; Concanavalin A; Female; Interferon-gamma; Interleukin-4; Ligands; Liver; Macrophage Inflammatory Proteins; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Receptors, CCR5; Severity of Illness Index; T-Lymphocytes; Tumor Necrosis Factor-alpha

Concanavalin A-induced hepatitis is often used as a model of liver injury. In this model, plasma tumor necrosis factor-alpha (TNF-alpha) level increased in concanavalin A-injected mice. Prophylactic treatment with Y-40138, N-[1-(4-[4-(pyrimidin-2-yl)piperazin-1-yl]methyl phenyl)cyclopropyl] acetamide.HCl, significantly suppressed the increase in plasma TNF-alpha level. In this study, we compared the effect of Y-40138 with those of pentoxifylline and anti-TNF-alpha antibody on concanavalin A-induced hepatitis. Prophylactic treatment with pentoxifylline, anti-TNF-alpha antibody and Y-40138 reduced plasma alanine aminotransferase level. Therapeutic treatment with Y-40138 significantly reduced plasma alanine aminotransferase level, but pentoxifylline and anti-TNF-alpha antibody did not. Therapeutic treatment with Y-40138 significantly reduced plasma interferon-gamma (IFN-gamma) and monokine induced by interferon-gamma levels. From these results, Y-40138 may be expected as a new class of therapeutic drug for treatment of TNF-alpha, IFN-gamma and/or chemokine-related liver diseases such as alcoholic liver disease.

Topics: Acetamides; Alanine Transaminase; Animals; Antibodies; Chemical and Drug Induced Liver Injury; Chemokines, CXC; Concanavalin A; Cytokines; Disease Models, Animal; Female; Interferon-gamma; Mice; Mice, Inbred BALB C; Pentoxifylline; Piperazines; Premedication; Time Factors; Tumor Necrosis Factor-alpha

Unlike T cells, the role of natural killer (NK) cells is not well documented in the concanavalin (ConA)- induced hepatitis model. This study aimed to investigate the regulatory effect of high levels of interferon-gamma (IFN-gamma) on NK cells in ConA-induced hepatitis. The cytotoxicities of NK cells from ConA-injected mice or NK cell lines (NK92 and NKL) were detected by the 4-h 51Cr release assay. Depletion of NK cells with AsGM1 antibody was used to assess the NK cell role in ConA-induced hepatitis. Expression of NK cell receptors and cytotoxic molecules was measured by reverse transcription-polymerase chain reaction. Twelve hours after ConA injection, serum IFN-gamma was significantly increased in wild mice, but not in severe combined immunodeficiency mice, and hepatic NK cells exerted impaired cytotoxicity against YAC-l cells in wild mice. Eight hours after NK cells were incubated in serum from ConA-treated mice, NK cell cytotoxicity was down-modulated and the effect was abolished by pretreatment with neutralizing serum IFN-gamma with specific antibody in vitro. A high concentration of IFN-gamma (> 1000 U/mL) inhibited the cytotoxicities of 2 NK cell lines in vitro, accompanied with down-regulation of NKG2D transcripts and up-regulation of NKG2A/B and KIR2DL transcripts. The inhibitive role of IFN-gamma was not seen in NKG2D ligand negative cells. These results suggest that NK cell cytotoxicity was inhibited by high levels of IFN-gamma in ConA-induced hepatitis, which may relate to the dispensable role of NK cells.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytotoxicity, Immunologic; Drug Resistance; Gene Expression Regulation; Interferon-gamma; Killer Cells, Natural; Liver; Male; Mice; Mice, Inbred Strains; Mice, SCID; NK Cell Lectin-Like Receptor Subfamily C; NK Cell Lectin-Like Receptor Subfamily K; Receptors, Immunologic; Receptors, Natural Killer Cell; Recombinant Proteins

To investigate the protective effects of the granule of Sambucus chinensis Lindl on acute hepatic injury.. The acute liver-injury model induced by CCl4 or D-GalN or ConA was established in mice or rats.. The granule of Sambucus chinensis Lindl showed significantly protective effects on mice acute hepatic injury induced by CCl4 ,and the effects were concern of antagonizing lipoperoxidation and improving energy of Ca2+ -ATPase of theca mitochondria and microsome. It showed significantly protective effects on mice or rats acute hepatic injury induced by D-GalN or Con A, too.. The granule of Sambucus chinensis Lindl showed significantly protective effects against many kinds of chemical and immunological liver injuries.

Topics: Animals; Aspartate Aminotransferases; Biomarkers; Calcium-Transporting ATPases; Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Liver; Male; Malondialdehyde; Mice; Plants, Medicinal; Rats; Rats, Wistar; Sambucus; Sodium-Potassium-Exchanging ATPase; Transaminases

Viral hepatitis and autoimmune liver diseases cause hepatocyte apoptosis. Concanavalin A (Con A)-induced hepatitis resembles human viral hepatitis and autoimmune hepatitis. The role of nitric oxide (NO) in liver injury was controversial in different liver injury models. We hypothesize both endogenous and exogenous NO protect liver against Con A-induced liver injury. Molsidomine is metabolized into SIN-1 by the liver, and SIN-1 subsequently generates NO. So, molsidomine was used as a NO donor in this study.. To study a protective role of endogenous NO in Con A-induced liver injury, mice were pretreated with a specific inducible nitric oxide synthase (iNOS) inhibitor, L-N(6)-(1-iminoethyl)-lysine (L-NIL), before Con A challenge. To study a time-dependent protection against Con A-induced liver injury, animals were either given molsidomine, a NO donor, before or after Con A administration. Serum alanine aminotranferase (ALT) was analyzed. Liver samples were subjected to DNA fragmentation assay, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling stain, Western blot analysis, and caspase activity assays.. Animals pretreated with L-NIL had significantly increased serum ALT levels compared with those challenged with Con A alone; but pretreatment with molsidomine dramatically decreased ALT levels in L-NIL-pretreated animals or in animals that received Con A alone. Administration of molsidomine 30 minutes before or 1, 2, and 3 hours after Con A injection significantly reduced serum ALT levels and attenuated hepatocyte apoptosis from caspase inactivation. The ALT reduction was associated with inhibition of both caspase-3 and caspase-8 activation and reduction of hepatocyte apoptosis.. Endogenous NO plays an important protective role against Con A-induced liver injury by reducing hepatocyte apoptosis. Administration of a NO donor early after Con A injection protects the liver from injury. This is the first study demonstrating a time-dependent inhibition of liver injury induced by Con A administration.

Topics: Alanine Transaminase; Animals; Apoptosis; Caspase 3; Caspase 8; Caspase 9; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; Enzyme Inhibitors; Female; Hepatocytes; Lysine; Mice; Mice, Inbred BALB C; Molsidomine; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Time Factors

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

Alcohol consumption is a major risk factor accelerating the progression of liver disease in patients with chronic hepatitis virus infection. However, the mechanism underlying the enhanced susceptibility of alcoholics to liver injury is not fully understood. Here, we demonstrate that chronic ethanol consumption increases the susceptibility of C57BL/6 mice to concanavalin A (Con A)-induced T cell-mediated hepatitis. Injection of a low dose of Con A (5 microg/g) causes severe liver damage in ethanol-fed mice as evidenced by a significant elevation of serum alanine aminotransaminase levels, massive necrosis, and infiltration of leukocytes but only slightly induces liver injury in control pair-fed mice. In ethanol-fed mice, the activation and cytotoxicity of natural killer T cells, cells that play key roles in Con A-induced T cell hepatitis, are not significantly enhanced relative to pair-fed mice. Moreover, Con A-induced activation of hepatic NF-kappaB is increased, whereas activation of STAT1 and STAT3 is attenuated in ethanol-fed mice. Consistent with this result, the expression of chemokines and adhesion molecules [such as ICAM-1, macrophage inflammatory protein (MIP)-1, MIP-2, and MCP-1] controlled by NF-kappaB is upregulated, whereas STAT1-controlled expression of chemokines (such as MIG and IP-10) is downregulated in ethanol-fed mice compared with pair-fed mice. In conclusion, chronic alcohol consumption accelerates T cell-mediated hepatitis via upregulation of the NF-kappaB signaling pathway and subsequently enhances expression of chemokines/adhesive molecules and recruitment of leukocytes into the liver. Downregulation of the antiapoptotic STAT3 signal may also contribute to alcohol potentiation of T cell hepatitis.

Topics: Alcohol Drinking; Animals; Cell Adhesion Molecules; Chemical and Drug Induced Liver Injury; Chemokines; Concanavalin A; DNA-Binding Proteins; Ethanol; Hepatocytes; Killer Cells, Natural; Leukocytes; Liver; Male; Mice; Mice, Inbred C57BL; Monocytes; NF-kappa B; Signal Transduction; STAT3 Transcription Factor; T-Lymphocytes; Time Factors; Trans-Activators

The aim of this study was to evaluate the effect of astilbin on concanavalin A (Con A)-induced hepatitis, a T cell-dependent model of liver injury. Con A administration resulted in a severe liver injury in mice, with a strong increment in spleen cell adhesion and liver infiltration of T cells, as well as in tumour necrosis factor (TNF)-alpha production. Against this liver injury, astilbin significantly inhibited the elevation in transaminase activity, reduced the TNF-alpha production, and improved the histological changes, including inflammatory infiltration, hepatocyte necrosis and degeneration and Kupffer cell hyperplasia. In addition, astilbin inhibited the adhesion of spleen cells and purified T lymphocytes isolated from the liver-injured mice to fibronectin, laminin and type IV collagen.Moreover, the adhesion of human Jurkat T cells to endothelial cell line ECV-304 was also inhibited by astilbin. These results suggest that the improvement of the T cell-mediated liver injury by astilbinmay be related to the reduction in TNF-alpha production and in T cell adhesion to extracellular matrices and endothelial cells.

Topics: Animals; Cell Adhesion; Chemical and Drug Induced Liver Injury; Collagen Type IV; Concanavalin A; Extracellular Matrix; Female; Fibronectins; Flavonols; Humans; Jurkat Cells; Laminin; Liver; Male; Mice; Mice, Inbred ICR; Plant Extracts; Smilax; T-Lymphocytes; Tumor Necrosis Factor-alpha

The central role of T cell activation in hepatocellular injury has been well documented. In this article, we provide evidence suggesting that T cells may also play a protective role in liver disease by releasing interleukin-22 (IL-22), a recently identified T cell-derived cytokine whose biological significance is unclear. IL-22 messenger RNA and protein expression are significantly elevated in T cell-mediated hepatitis induced by concanavalin A (ConA) but are less extensively elevated in the carbon tetrachloride-induced liver injury model. Activated CD3(+) T cells are likely responsible for the production of IL-22 in the liver after injection of ConA. The IL-22 receptor is normally expressed at high levels by hepatocytes and further induced after ConA injection. IL-22 blockade with a neutralizing antibody reduces signal transducer and activator of transcription factor 3 (STAT3) activation and worsens liver injury in T cell-mediated hepatitis, whereas injection of recombinant IL-22 attenuates such injury. In vitro treatment with recombinant IL-22 or overexpression of IL-22 promotes cell growth and survival in human hepatocellular carcinoma HepG2 cells. Stable overexpression of IL-22 in HepG2 cells constitutively activates STAT3 and induces expression of a variety of antiapoptotic (e.g., Bcl-2, Bcl-xL, Mcl-1) and mitogenic (e.g., c-myc, cyclin D1, Rb2, CDK4) proteins. Blocking STAT3 activation abolishes the antiapoptotic and mitogenic actions of IL-22 in hepatic cells. In conclusion, the T cell-derived cytokine IL-22 is a survival factor for hepatocytes; this suggests that T cell activation may also prevent and repair liver injury by releasing hepatoprotective cytokine IL-22 in addition to its previously documented central role in hepatocellular injury.

Topics: Agar; Animals; Carcinoma, Hepatocellular; Cell Division; Cell Line, Tumor; Cell Survival; Chemical and Drug Induced Liver Injury; Concanavalin A; DNA-Binding Proteins; Hepatitis; Hepatocytes; Humans; Interleukin-22; Interleukins; Liver Neoplasms; Mice; Mice, Nude; Neoplasm Transplantation; Receptors, Interleukin; STAT3 Transcription Factor; T-Lymphocytes; Trans-Activators

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

Bicyclol, 4, 4'-dimethoxy-5, 6, 5', 6'-dimethylene-dioxy-2-hydroxymethyl -2'-carbonyl biphenyl, is a new anti-hepatitis drug. The aim of the present study was to investigate the protective effect of bicyclol on concanavalin A (Con A)-induced immunological liver injury in mice and its mechanism.. Liver injury was induced by injection of Con A via tail vein of mice and assessed biochemically and histologically. Serum transaminase and tumor necrosis factor alpha (TNF-alpha) were determined. Liver lesions were observed by light microscope. Expressions of TNF-alpha, interferon gamma (IFN-gamma), Fas and Fas ligand (FasL) mRNA in the livers were measured by RT-PCR.. Serum transaminase level and liver lesions in Con A-induced mice were markedly reduced by oral administration of 100, 200 mg/kg of bicyclol. TNF-alpha level in serum was also reduced by bicyclol. Con A injection induced up-regulation of TNF-alpha, IFN-gamma, Fas and FasL mRNA expression in liver tissues. Bicyclol significantly down-regulated the expression of IFN-gamma, Fas and FasL mRNA, but only slightly affected TNF-alpha mRNA expression in liver tissues.. Bicyclol protects against Con A-induced liver injury mainly through inhibition of Fas/FasL mRNA expression in liver tissues and TNF-alpha release in mice.

Topics: Animals; Apoptosis; Biphenyl Compounds; Chemical and Drug Induced Liver Injury; Concanavalin A; Fas Ligand Protein; fas Receptor; Gene Expression; Interferon-gamma; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; RNA, Messenger; Transaminases; Tumor Necrosis Factor-alpha

Fumigaclavine C, an alkaloidal metabolite, was produced by Aspergillus fumigatus (strain No. CY018). This study examined the effect of this compound on concanavalin A (Con A)-induced liver injury in mice, a T cell-dependent model of liver damage. Con A administration resulted in severe liver injury, T lymphocyte activation and a strong increment in spleen cell adhesion, as well as in tumour necrosis factor-alpha (TNF-alpha) production. Against this liver injury, the intraperitoneal administration of fumigaclavine C dose-dependently inhibited the elevation in transaminase activity, TNF-alpha production in serum and the histological changes, including inflammatory infiltration, hepatocyte necrosis and degeneration and Kupffer cell hyperplasia. In addition, this compound in-vitro also inhibited the proliferation of spleen cells induced by Con A, and reduced their IL-2 and TNF-alpha production. Moreover, the intraperitoneal administration of fumigaclavine C inhibited the potential of spleen cells isolated from the liver-injured mice to adhere to fibronectin, laminin and type IV collagen. These results suggest that the improvement of this T cell-mediated liver injury by fumigaclavine C may be related to the inhibition of lymphocyte activation, proliferation and adhesion to extracellular matrices as well as the reduction in TNF-alpha production.

Topics: Alkaloids; Animals; Aspergillus fumigatus; Cell Adhesion; Cell Division; Chemical and Drug Induced Liver Injury; Concanavalin A; Dose-Response Relationship, Drug; Ergot Alkaloids; Extracellular Matrix; Female; In Vitro Techniques; Indole Alkaloids; Injections, Intraperitoneal; Interleukin-2; Liver; Male; Mice; Spleen; T-Lymphocytes; Tumor Necrosis Factor-alpha

T cell-mediated hepatitis is associated with significant morbidity and mortality worldwide. Levels of C-C chemokine ligand 3/macrophage inflammatory protein-1alpha (CCL3/MIP-1alpha) are elevated in the serum of patients with T cell-mediated liver diseases, but its role is not fully understood. Con A-induced hepatitis is a murine liver-specific inflammation mediated by activated T cells and is driven by an up-regulation of the hepatic expression of IFN-gamma. In this study, we have used CCL3/MIP-1alpha gene-deficient mice to examine the role of CCL3/MIP-1alpha in the pathogenesis of Con A-induced hepatitis. We demonstrate a novel pro-inflammatory role for CCL3/MIP-1alpha since CCL3/MIP-1alpha deficiency significantly attenuated hepatic injury, both biochemically and histologically. Moreover, the recruitment of CCR1-expressing CD4(+) T cells to the liver after Con A treatment was strikingly attenuated by CCL3/MIP-1alpha deficiency. Correspondingly, hepatic IFN-gamma produced by the recruited CD4(+) T cells was significantly reduced by CCL3/MIP-1alpha deficiency during Con A-induced hepatitis. Furthermore, treatment of mice with a dual CCR1/CCR5 peptide antagonist, methionylated RANTES, also markedly reduced hepatic injury and decreased the numbers of CD4(+) T cells within the liver producing IFN-gamma during Con A-induced hepatitis. These findings demonstrate that blockade of the CCL3/MIP-1alpha-CCR1 pathway may represent a novel therapeutic target for treating T cell-mediated liver diseases.

Topics: Animals; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Chemokine CCL3; Chemokine CCL4; Chemokine CCL5; Concanavalin A; Disease Models, Animal; Flow Cytometry; Fluorescent Antibody Technique; Interferon-gamma; Liver; Macrophage Inflammatory Proteins; Male; Mice; Mice, Knockout; Neutrophil Infiltration; Receptors, CCR1; Receptors, CCR5; Receptors, Chemokine

Dehydroepiandrosterone (DHEA), one of the major androgens secreted by the adrenal cortex, has been shown to have potential immunoreguratory properties. In this study, we examined the effect of DHEA in a mouse model of hepatitis. Mice were treated with DHEA and injected with concanavalin A (Con A) or lipopolysaccharide (LPS)/D-galactosamine (GalN). Cytokine expression was measured by quantitative RT-PCR and ELISA. Apoptosis was detected by the TUNEL method and by DNA fragmentation analysis. In the DHEA-treated mice, the serum levels of ALT and expression of inflammatory mediators were significantly decreased. The number of apoptotic cells was also much lower than that observed in control, untreated mouse liver tissue. There were fewer tumor necrosis factor-alpha (TNF-alpha)-induced apoptotic cells in H4IIE hepatoma cells treated with DHEA than in non-treated cells. DHEA decreased the expression levels of mRNA transcripts encoding TNF-alpha and iNOS. These results suggest that DHEA can reduce T-cell-mediated injury in the liver as manifest by inhibition of the expression of several inflammatory mediators and hepatocyte apoptosis. DHEA should, thus, be considered as a novel candidate for the therapy of liver injury.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Dehydroepiandrosterone; Disease Models, Animal; DNA Fragmentation; Hepatocytes; Lipopolysaccharides; Mice; Mice, Inbred BALB C

PKCzeta is required for nuclear factor kappa-B (NF-kappaB) activation in several cell systems. NF-kappaB is a suppressor of liver apoptosis during development and in concanavalin A (ConA)-induced T-cell-mediated hepatitis. Here we show that PKCzeta-/- mice display inhibited ConA-induced NF-kappaB activation and reduced damage in liver. As the IL-4/Stat6 pathway is necessary for ConA-induced hepatitis, we addressed here the potential role of PKCzeta in this cascade. Interestingly, the loss of PKCzeta severely attenuated serum IL-5 and liver eotaxin-1 levels, two critical mediators of liver damage. Stat6 tyrosine phosphorylation and Jak1 activation were ablated in the liver of ConA-injected PKCzeta-/- mice and in IL-4-stimulated PKCzeta-/- fibroblasts. PKCzeta interacts with and phosphorylates Jak1 and PKCzeta activity is required for Jak1 function. In contrast, Par-4-/- mice have increased sensitivity to ConA-induced liver damage and IL-4 signaling. This unveils a novel and critical involvement of PKCzeta in the IL-4/Stat6 signaling pathway in vitro and in vivo.

Topics: Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Chemokine CCL11; Chemokines, CC; Concanavalin A; Enzyme Activation; Fibroblasts; Interleukin-4; Interleukin-5; Janus Kinase 1; Liver; Mice; Mice, Knockout; NF-kappa B; Phosphorylation; Protein Kinase C; Protein-Tyrosine Kinases; Receptors, Thrombin; Signal Transduction; STAT6 Transcription Factor; T-Lymphocytes; Trans-Activators

Interleukin-22 (IL-22) is a recently identified T cell-derived cytokine whose biological significance remains obscure. Previously, we have shown that IL-22 plays a protective role in T cell-mediated hepatitis induced by Concanavalin A (Con A), acting as a survival factor for hepatocytes. In the present paper, we demonstrate that hydrodynamic gene delivery of IL-22 cDNA driven either by a liver-specific albumin promoter or a human cytomegalovirus (CMV) promoter results in IL-22 protein expression, STAT3 activation, and expression of several anti-apoptotic proteins, including Bcl-xL, Bcl-2, and Mcl-1 in the liver. Immunohistochemical analysis reveals that IL-22 protein expression is mainly detected in the cytoplasm of hepatocytes. Overexpression of IL-22 by hydrodynamic gene delivery significantly protects against liver injury, necrosis, and apoptosis induced by administration of Con A, carbon tetrachloride (CCl4), or the Fas agonist Jo-2 mAb. Western blot analyses show that overexpression of IL-22 significantly enhances activation of STAT3 and expression of Bcl-xL, Bcl-2, and Mcl-1 proteins in liver injury induced by Con A. In conclusion, hydrodynamic gene delivery of IL-22 protects against liver injury induced by a variety of toxins, suggesting the therapeutic potential of IL-22 in treating human liver disease.

Topics: Animals; bcl-X Protein; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Concanavalin A; Fas Ligand Protein; Gene Transfer Techniques; Humans; Interleukin-22; Interleukins; Liver; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins; Proto-Oncogene Proteins c-bcl-2; STAT3 Transcription Factor; Tumor Necrosis Factors

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

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

Inosine is an endogenous nucleoside with immunosuppressive properties that is known to inhibit the accumulation of proinflammatory cytokines and protect mice from endotoxin-induced inflammation and lung tissue damage. There are no known receptors specific for inosine, but A3 adenosine receptors (A3Rs) have been shown to bind inosine, resulting in mast cell degranulation and increased vascular permeability. The present study specifically addresses the requirement for A2aR and/or A3R for the protective effect of inosine in 2 experimental in vivo models of inflammatory disease. The data show that A3R is essential for protection against ConA-induced fulminant hepatitis since only A3R-expressing mice were protected by inosine whereas wild-type and A2aR-deficient mice exhibited severe liver damage even after administration of inosine. In addition, we show in a model of LPS-induced endotoxemia that inosine protected both A2aR-/- and A3R-/- mice from inflammation, but not A2aA3R double-null mice, indicating that in this model both A2aR and A3R were used by inosine. Thus, we demonstrate that A2a and A3 adenosine receptors are differentially utilized by inosine for the down-regulation of tissue damage under different inflammatory conditions in vivo.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Endotoxemia; Hepatocytes; Immunosuppressive Agents; Inosine; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Receptor, Adenosine A2A; Receptor, Adenosine A3; Tumor Necrosis Factor-alpha

P-selectin (CD62P) is an adhesion molecule that mediates the initial attachment of leukocytes to activated platelets and endothelial cells in damaged tissues. We evaluated the role of P-selectin in concanavalin A (Con A)-induced hepatitis, a model characterized by CD4(+) T cell activation and infiltration of the liver. Con A injection induced transient P-selectin expression on hepatic venules and platelets. Mice lacking P-selectin showed impaired lymphocyte adhesion to liver venules and sinusoids, a striking reduction in intrasinusoidal occlusion, and decreased lymphocyte infiltration of liver parenchyma. The reduction in transaminase levels and the almost complete abolition of necrotic injury demonstrated that liver damage was lower in P-selectin-deficient mice. In wild-type mice, pretreatment with the P-selectin-blocking monoclonal antibody attenuated the sinusoidal occlusion and reduced the rise in transaminases after Con A treatment. These results implicate P-selectin in the development of Con A-induced liver injury and reveal the protective effect of blocking P-selectin in this hepatitis.

Topics: Alanine Transaminase; Animals; Antibodies, Monoclonal; Aspartate Aminotransferases; Autoimmune Diseases; Blood Platelets; CD4-Positive T-Lymphocytes; Cell Adhesion; Chemical and Drug Induced Liver Injury; Chemotaxis, Leukocyte; Concanavalin A; Disease Models, Animal; Endothelium, Vascular; Gene Expression Regulation; Hemostasis; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Necrosis; P-Selectin; Specific Pathogen-Free Organisms

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

Viral hepatitis affects more than 2 billion people worldwide. In particular, no effective treatment exists to abrogate death and liver damage in fulminant hepatitis. Activation of T cells is an initial and critical event in the pathogenesis of liver damage in autoimmune and viral hepatitis. The precise molecular mechanisms that induce T cell-mediated hepatocyte injury remain largely unclear. In mice, T cell-dependent hepatitis and acute liver damage can be modeled using ConA. In this study, we examined the role of the adhesion receptor LFA-1 in ConA-induced acute hepatic damage using LFA-1(-/-) (CD11a) mice. Massive liver cell apoptosis and metabolic liver damage were observed in LFA-1(+/+) mice following ConA injection. By contrast, LFA-1(-/-) mice were completely resistant to ConA-induced hepatitis and none of the LFA-1(-/-) mice showed any hepatic damage. Whereas activated hepatic T cells remained in the liver in LFA-1(+/+) mice, activated T cells were rapidly cleared from the livers of LFA-1(-/-) mice. Mechanistically, T cells from LFA-1(-/-) mice showed markedly reduced cytotoxicity toward liver cells as a result of impaired, activation-dependent adhesion. Importantly, adoptive transfer of hepatic T cells from LFA-1(+/+) mice, but not from LFA-1(-/-) mice, sensitized LFA-1(-/-) mice to ConA-induced hepatitis. Thus, LFA-1 expression on T cells is necessary and sufficient for T cell-mediated liver damage in vivo. These results provide the first genetic evidence on an adhesion receptor, LFA-1, that has a crucial role in fulminant hepatitis. These genetic data identify LFA-1 as a potential key target for the treatment of T cell-mediated hepatitis and the prevention of liver damage.

Topics: Adoptive Transfer; Animals; Antibodies, Monoclonal; Antigens; Antigens, Surface; Cell Adhesion; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytotoxicity, Immunologic; Injections, Intravenous; Intercellular Adhesion Molecule-1; Killer Cells, Natural; Lectins, C-Type; Liver; Lymphocyte Activation; Lymphocyte Function-Associated Antigen-1; Mice; Mice, Inbred C57BL; Mice, Knockout; NK Cell Lectin-Like Receptor Subfamily B; Protein Biosynthesis; Proteins; Receptors, Antigen, T-Cell, alpha-beta; T-Lymphocyte Subsets

Leptin-deficient ob/ob mice are protected from Con A-induced hepatitis. However, it is unclear whether leptin deficiency or obesity itself is responsible for this protection. To address this question, wild-type (WT) obese mice with high serum leptin levels were generated by injection of gold thioglucose (WT GTG). Both Con A-injected WT and WT GTG mice developed hepatitis, whereas no hepatic damage was observed in ob/ob mice. Moreover, TNF-alpha and IFN-gamma levels as well as expression of the activation marker CD69 were elevated in liver mononuclear cells of WT and WT GTG mice, but not in ob/ob mice following administration of Con A. The liver of WT and WT GTG mice had the same percentage of NK T cells, a lymphocyte population involved in Con A-induced hepatitis. This population decreased equally in both WT and WT GTG mice after Con A injection. In contrast, the liver of ob/ob mice contained 50% less NK T cells compared to WT and WT GTG mice. Furthermore, no decrease in NK T cells was observed in Con A-injected ob/ob mice. We conclude that leptin-deficiency, not obesity, is responsible for protection from Con A-induced hepatitis.

Topics: Animals; Aurothioglucose; Body Weight; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Interferon-gamma; Killer Cells, Natural; Leptin; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Obese; Obesity; T-Lymphocyte Subsets; Tumor Necrosis Factor-alpha

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

Eosinophils are observed in several liver diseases, but their contribution in the pathogenesis of these disorders remains poorly investigated. Concanavalin A (Con A)-induced hepatitis is an experimental model of immune-mediated liver injury in which natural killer T (NKT) cells play a critical role through the production of interleukin (IL)-4 and the expression of Fas ligand (FasL). Because activated NKT cells also produce IL-5, a critical cytokine for eosinophil maturation and function, the role of IL-5 was investigated in this model.. IL-5-deficient mice, eosinophil depletion in wild-type (WT) mice, and NKT cell transfer from WT- or IL-5-deficient mice into NKT cell-deficient mice were used to assess the role of IL-5 and eosinophils.. Liver eosinophil infiltrate and IL-5 production were observed after Con A challenge. Liver injury was dramatically reduced in IL-5-deficient or eosinophil-depleted mice. In addition, residual hepatitis observed in Fas-deficient mice was abolished after IL-5 neutralization. Finally, we showed that NKT cells constituted a critical source of IL-5. Indeed, transfer of WT NKT cells to mice lacking NKT cells restored liver injury, whereas transfer of IL-5-deficient NKT cells did not.. These observations highlight the pathologic role of IL-5 and eosinophils in experimental immune-mediated hepatitis.

Topics: Animals; Antibodies, Monoclonal; Chemical and Drug Induced Liver Injury; Concanavalin A; Eosinophils; fas Receptor; Interleukin-5; Killer Cells, Natural; Mice; Mice, Inbred C57BL; Mice, Knockout

TNF-alpha has been clearly identified as central mediator of T cell activation-induced acute hepatic injury in mice, e.g., Con A hepatitis. In this model, liver injury depends on both TNFRs, i.e., the 55-kDa TNFR1 as well as the 75-kDa TNFR2. We show in this report that the hepatic TNFRs are not transcriptionally regulated, but are regulated by receptor shedding. TNF directly mediates hepatocellular death by activation of TNFR1 but also induces the expression of inflammatory proteins, such as cytokines and adhesion molecules. Here we provide evidence that resistance of TNFR1(-/-) and TNFR2(-/-) mice against Con A hepatitis is not due to an impaired production of the central mediators TNF and IFN-gamma. Con A injection results in a massive induction of ICAM-1, VCAM-1, and E-selectin in the liver. Lack of either one of both TNFRs did not change adhesion molecule expression in the livers of Con A-treated mice, presumably reflecting the fact that other endothelial cell-activating cytokines up-regulated adhesion molecule expression. However, treatment of TNFR1(-/-) and TNFR2(-/-) mice with murine rTNF revealed a predominant role for TNFR1 for the induction of hepatic adhesion molecule expression. Pretreatment with blocking Abs against E- and P-selectin or of ICAM(-/-) mice with anti-VCAM-1 Abs failed to prevent Con A hepatitis, although accumulation of the critical cell population, i.e., CD4(+) T cells was significantly inhibited. Hence, up-regulation of adhesion molecules during acute hepatitis unlikely contributes to organ injury but rather represents a defense mechanism.

Topics: Animals; Antibodies, Monoclonal; Antigens, CD; CD4-Positive T-Lymphocytes; Cell Adhesion Molecules; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; E-Selectin; Injections, Intraperitoneal; Injections, Intravenous; Intercellular Adhesion Molecule-1; Liver; Liver Failure, Acute; Lymphocyte Function-Associated Antigen-1; Male; Mice; Mice, Inbred BALB C; Mice, Knockout; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Receptors, Tumor Necrosis Factor, Type II; Recombinant Proteins; RNA, Messenger; Solubility; Tumor Necrosis Factor-alpha; Up-Regulation; Vascular Cell Adhesion Molecule-1

Anorexia that develops in chronic hepatitis is associated with cytokine expression in the brain. Treatment of mice with concanavalin A (12.5 mg/kg, i.v.) elevated the plasma alanine aminotransferase activity at 8.5 h after treatment. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta mRNA expression was induced at 6 and 24 h after concanavalin A treatment in both the liver and brain. Treatment of mice with concanavalin A reduced the body weight at 24 h after treatment and this decreased body weight was accompanied by a decreased food intake. Glycyrrhizin (200 mg/kg, i.p.) inhibited the concanavalin A-induced elevation of plasma alanine aminotransferase activity, however, it did not inhibit the concanavalin A-induced decreased body weight. The present results indicate that treatment of mice with concanavalin A caused the development of anorexia and that this anorexia might develop independently of the induction of hepatitis.

Topics: Alanine Transaminase; Animals; Anorexia; Body Weight; Brain; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Eating; Female; Glycyrrhizic Acid; Hepatitis, Animal; Interleukin-1; Liver; Mice; Mice, Inbred BALB C; RNA, Messenger; Tumor Necrosis Factor-alpha

Molsidomine is effective in reducing portal hypertension in cirrhosis, but its effect on hepatitis is not known. In the present study, the effect of molsidomine on hepatitis was examined using mouse concanavalin A (Con A)-induced hepatitis and mouse anti-Fas antibody-induced hepatitis. Treatment of mice with Con A caused elevation of plasma alanine aminotransferase (ALT) at 8 and 24 h (n=4). Pretreatment of mice with molsidomine (3, 10, 30 and 100 mg/kg, i.p.) prevented Con A-induced hepatitis. Treatment of mice with anti-Fas antibody (150 microg/kg, i.v.) caused elevation of plasma ALT at 3.5 h. Pretreatment mice with molsidomine (10 mg/kg, i.p.) showed only 47% inhibition of anti-Fas antibody caused elevation of plasma ALT. The present results showed effectiveness of molsidomine in preventing Con A-induced mice hepatitis.

Topics: Alanine Transaminase; Animals; Antibodies; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; fas Receptor; Female; Mice; Mice, Inbred BALB C; Molsidomine; Vasodilator Agents

The functions of leukocyte-derived chemotaxin 2 (LECT2), a novel liver-specific protein, are not well defined, especially after hepatic injury. The changes in expression of LECT2 mRNA were investigated after concanavalin A (Con A)-induced hepatic injury in mice. Serum glutamate pyruvate transaminase (s-GPT) activity and the percentage of liver DNA fragmentation, an indicator of hepatic apoptosis, increased 8 h after intravenous administration of Con A (13 mg/kg). Expression of LECT2 mRNA was reduced from 8-24 h after injection of Con A, but was detected again 48 h after recovery from hepatic injury. Expression of tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma mRNA was observed in liver 2 h after Con A injection. Z-Val-Ala-Asp(OMe)-CH2F (Z-VAD-FMK), a caspase inhibitor, was administered to mice to investigate whether LECT2 was involved in apoptosis of liver cells after Con A injection. Z-VAD-FMK inhibited s-GPT activity and DNA fragmentation in the liver 8 h after Con A-induced hepatic injury, but did not prevent the reduction of LECT2 mRNA, or induction of TNF-alpha and IFN-gamma mRNA expression. When the relation between expression of LECT2, TNF-alpha and IFN-gamma mRNAs was examined 8 h after Con A injection in wild-type or immunodeficient (nu-/nu-) mice, the increase in TNF-alpha and IFN-gamma mRNA expression was found to be closely related to a reduction in LECT2 mRNA expression. These results suggest that the reduction in expression of LECT2 mRNA is not directly involved in apoptosis and may be inversely related to the expression of TNF-alpha and/or IFN-gamma mRNA in the injured liver.

Topics: Alanine Transaminase; Animals; Blotting, Western; Caspase Inhibitors; Chemical and Drug Induced Liver Injury; Chemotactic Factors; Concanavalin A; DNA Fragmentation; Enzyme Inhibitors; Female; Intercellular Signaling Peptides and Proteins; Interferon-gamma; Liver; Liver Function Tests; Mice; Mice, Inbred BALB C; Protein Biosynthesis; RNA, Messenger; Tumor Necrosis Factor-alpha

NC-1500 is a dihydropyridine type calcium channel blocker. The effect of NC-1500 on mice concanavalin A-induced hepatitis was examined. Treatment of mice with concanavalin A (Con A) caused elevation of plasma transaminase. Pretreatment of mice with NC-1500 (3, 10 and 30 mg/kg, p.o.) prevented this Con A-induced elevation of plasma transaminase. Treatment of mice with Con A induced tumor necrosis factor-alpha (TNF-alpha) mRNA expression in the liver. However, NC-1500 (30 mg/kg, p.o.) did not affect this Con A-induced TNF-alpha mRNA expression in the liver. The present results showed that NC-1500 inhibited Con A-induced hepatitis without affecting TNF-alpha mRNA expression in the liver.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Aspartate Aminotransferases; Calcium Channel Blockers; Chemical and Drug Induced Liver Injury; Concanavalin A; Dihydropyridines; Disease Models, Animal; Female; Gene Expression; Glycyrrhizic Acid; Mice; Mice, Inbred BALB C; Naphthyridines; RNA, Messenger; Tumor Necrosis Factor-alpha

Liver resident NK1.1+ T cells are supposed to play a pivotal role in the onset of inflammatory liver injury in experimental mouse models such as concanavalin A (Con A)-induced hepatitis. These cells, expressing the adhesion receptor, CD44, are largely depleted from the liver by a single intravenous injection of low-molecular-weight fragments of hyaluronic acid (LMW-HA). Here, we report that LMW-HA pretreatment protected mice from liver injury in several models of T-cell- and macrophage-dependent, tumor necrosis factor alpha (TNF-alpha)-mediated inflammatory liver injury, i.e., from liver injury induced by either Con A or Pseudomonas exotoxin A (PEA) or PEA/lipopolysaccharide (LPS). Interestingly, apart from inhibition of cellular adhesion, pretreatment of mice with LMW-HA was also capable of preventing hepatocellular apoptosis and activation of caspase-3 induced by direct administration of recombinant murine (rmu) TNF-alpha to D-galactosamine (GalN)-sensitized mice. LMW-HA-induced hepatoprotection could be neutralized by pretreatment with the nuclear factor-kappaB (NF-kappaB) inhibitor, pyrrolidine dithiocarbamate (PDTC), demonstrating the involvement of NF-kappaB in the observed protective mechanism. Indeed, injection of LMW-HA rapidly induced the production of TNF-alpha by Kupffer cells and the translocation of NF-kappaB into hepatocellular nuclei. Both LMW-HA-induced TNF-alpha production and NF-kappaB translocation were blocked by pretreatment with PDTC. Our findings provide evidence for an unknown mechanism of LMW-HA-dependent protection from inflammatory liver disease, i.e., induction of TNF-alpha- and NF-kappaB-dependent cytoprotective proteins within the target parenchymal liver cells.

Topics: ADP Ribose Transferases; Animals; Bacterial Toxins; CD4 Lymphocyte Count; Cell Death; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Exotoxins; Hyaluronan Receptors; Hyaluronic Acid; Kupffer Cells; Lipopolysaccharides; Liver; Liver Failure; Lymphocyte Count; Macrophages; Male; Mice; Mice, Inbred BALB C; Molecular Weight; NF-kappa B; Pseudomonas aeruginosa Exotoxin A; T-Lymphocytes; Tumor Necrosis Factor-alpha; Virulence Factors

Endothelial activation is an important feature of many inflammatory diseases and has been implicated as the cause of vascular complications in disorders such as diabetes, atherosclerosis, and transplant rejection. One of the most potent activators of the endothelium is TNF, which can also be expressed by endothelial cells, causing a permanent, autocrine stimulatory signal. To establish a model of continuous endothelial activation and to elucidate the role of endothelial derived TNF in vivo, we generated transgenic mice expressing a noncleavable transmembrane form of TNF under the control of the endothelial-specific tie2 promoter. Adult tie2-transmembrane TNF-transgenic mice developed chronic inflammatory pathology in kidney and liver, characterized by perivascular infiltration of mononuclear cells into these organs. Along with the infiltrate, an up-regulation of the adhesion molecules ICAM-1 and VCAM-1, but not E-selectin, in the endothelium was observed. Despite predisposition to chronic inflammation these mice were protected from immune-mediated liver injury in a model of Con A-induced acute hepatitis. Although the blood levels of soluble TNF and IFN-gamma were increased in transgenic animals after challenge with Con A, no damage of hepatocytes could be detected, as assessed by the lack of increase in plasma transaminase activities and the absence of TUNEL staining in the liver. We conclude that expression of transmembrane TNF in the endothelium causes continuous endothelial activation, leading to both proinflammatory and protective events.

Topics: Acute Disease; Animals; Cell Adhesion Molecules; Chemical and Drug Induced Liver Injury; Chronic Disease; Concanavalin A; Endothelium, Vascular; Inflammation; Kidney; Liver; Membrane Proteins; Mice; Mice, Transgenic; Receptor Protein-Tyrosine Kinases; Receptor, TIE-2; RNA, Messenger; Tumor Necrosis Factor-alpha; Up-Regulation

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

The administration of concanavalin A (Con A) induces a rapid severe injury of hepatocytes in mice. Although the Con A-induced hepatitis is considered to be an experimental model of human autoimmune hepatitis, the precise cellular and molecular mechanisms that induce hepatocyte injury remain unclear. Here, we demonstrate that Valpha14 NKT cells are required and sufficient for induction of this hepatitis. Moreover, interleukin (IL)-4 produced by Con A-activated Valpha14 NKT cells is found to play a crucial role in disease development by augmenting the cytotoxic activity of Valpha14 NKT cells in an autocrine fashion. Indeed, short-term treatment with IL-4 induces an increase in the expression of granzyme B and Fas ligand (L) in Valpha14 NKT cells. Moreover, Valpha14 NKT cells from either perforin knock-out mice or FasL-mutant gld/gld mice fail to induce hepatitis, and hence perforin-granzyme B and FasL appear to be effector molecules in Con A-induced Valpha14 NKT cell-mediated hepatocyte injury.

Topics: Adoptive Transfer; Animals; Antigens; Antigens, Surface; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytotoxicity, Immunologic; Interferon-gamma; Interleukin-4; Killer Cells, Natural; Lectins, C-Type; Male; Mice; Mice, Inbred C57BL; NK Cell Lectin-Like Receptor Subfamily B; Proteins; Receptors, Antigen, T-Cell, alpha-beta

Acute concanavalin A (Con A)-induced hepatitis in mice is an animal model for hepatic injury induced by activated T cells. The evolution of hepatic involvement can be followed from hour to hour by measuring serum transaminase levels. We investigated the possible role of endogenous interleukin-6 (IL-6) in this model. We found serum IL-6 levels and splenic IL-6 mRNA during Con A-induced hepatitis to be significantly lower in interferon-gamma (IFN-gamma)-deficient mice, which are resistant against the Con A-induced syndrome, than in wild-type ones, suggesting that systemic IL-6 production favors development of hepatic injury. However, IL-6-deficient mice proved to be more susceptible to the disease than wild-type mice, indicating that endogenous IL-6 plays a predominantly hepatoprotective role. Experiments in which wild-type mice were treated with anti-IL-6 antibodies, before or after Con A challenge, allowed us to reconcile these contrasting observations. The antibody injections resulted in a biphasic alteration of serum IL-6 levels, initial neutralization being followed by rebound increased levels due to accumulation of IL-6 in the form of antigen-antibody complexes. The effect of antibody on disease severity differed depending on the time of injection. Antibody injection at 2.5 h post Con A resulted in delayed disease manifestation, whereas treatment initiated before Con A resulted in accelerated disease. We conclude that endogenous IL-6 plays a bimodal role. IL-6 present before Con A challenge as well as that induced in the very early phase after Con A injection triggers hepatoprotective pathways. Continuation of IL-6 production beyond this early phase, by some other pathway, seems to be harmful to hepatocytes.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-6; Mice; Mice, Inbred BALB C

Concanavalin A (con A)-induced hepatitis is an immunomediated disease in which assembly of CD4(+) T cells and T helper (Th)1-like cytokines causes Fas-mediated liver cell death. Nitric oxide (NO) modulates Th1 response in vitro. NCX-4016 is an NO-aspirin derivative that spares the gastrointestinal tract and shares molecular targets with NO. The aim of this study was to investigate whether this NO-aspirin modulates Th1-like response induced by con A.. BALB/c mice were injected with 0.3 mg con A per mouse alone or in combination with NO-aspirin (18-100 mg/kg) or aspirin (10-55 mg/kg).. NO-aspirin, but not aspirin, caused a dose-dependent protection against liver damage induced by con A. At a dose of 100 mg/kg, NO-aspirin caused a 40%-80% reduction of interleukin (IL)-1beta, IL-12, IL-18, interferon (IFN)-gamma, and tumor necrosis factor alpha production without affecting cytokine messenger RNA expression. NO-aspirin prevented Fas, Fas ligand, and IL-2 receptor up-regulation on spleen lymphocytes and Fas ligand on hepatocytes and caused the S-nitrosylation/inhibition of IL-1beta-converting enzyme-like cysteine proteases (caspases) involved in the processing and maturation of IL-1beta and IL-18. IL-18 immunoneutralization prevented IFN-gamma release and protected from liver injury induced by con A. In contrast to a selective caspase 1 inhibitor, zVAD.FMK, a pancaspase inhibitor, prevented IFN-gamma release and protected the liver from injury.. Th1-like response induced by con A is mediated by IL-18 and requires activation of multiple caspases. NCX-4016 causes the S-nitrosylation/inhibition of caspases involved in cytokine production. Inhibition of Th1-like response is a new anti-inflammatory mechanism of action of NO-aspirin.

Topics: Amino Acid Chloromethyl Ketones; Animals; Aspirin; Caspase 1; Caspase 3; Caspase Inhibitors; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cysteine Proteinase Inhibitors; Cytokines; Fas Ligand Protein; fas Receptor; Interferon-gamma; Interleukin-18; Interleukins; Liver; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Platelet Aggregation Inhibitors; Receptors, Interleukin-2; RNA, Messenger; Spleen; T-Lymphocytes; Th1 Cells; Transcription, Genetic; Up-Regulation

Weekly injections of Concanavalin A (Con A) were performed in BALB/c mice to evaluate the pattern of cytokine production and liver injury. High serum levels of tumor necrosis factor alpha (TNF-alpha), interleukin 2 (IL-2), IL-4, and interferon gamma (IFN-gamma) were found in the serum after the first 2 injections of Con A but rapidly decreased from the third injection. Conversely, IL-10 serum levels after repeated Con A challenge increased by 7 times from week 1 to 20. In vivo depletion studies indicated that CD4(+) T cells are essential in IL-10 production. Hepatocyte necrosis was only observed after the first injections of Con A whereas centrilobular inflammatory infiltrates persisted up to 20 weeks. Perisinusoidal liver fibrosis was also increasingly detected in BALB/c mice, whereas no fibrous change was observed in nude mice after 6 weeks of Con A challenge. The number of stellate cells, detected by immunostaining, increased after 20 weeks of Con A injections. Liver cytokine messenger RNA (mRNA) expression after 20 weeks showed expression of transforming growth factor beta1 (TGF-beta1), IL-10, and IL-4 whereas IL-2 was no more expressed. The present study shows that mice repeatedly injected with Con A develop liver fibrosis. The cytokine-release pattern observed after 1 injection of Con A is rapidly shifted towards an immunomodulatory phenotype characterized by the systemic production of large amounts of IL-10.

Topics: Animals; CD4-Positive T-Lymphocytes; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Administration Schedule; Female; Interleukin-10; Liver; Liver Cirrhosis, Experimental; Mice; Mice, Inbred BALB C; Necrosis; Phenotype; Time Factors

Galectin-1, an endogenous lectin with immunomodulatory activities, induces selective, Fas-independent apoptosis of activated T cells. The aim of the present study was to evaluate the effect galectin-1 exerts on concanavalin A (Con A)-induced hepatitis, a T-cell-dependent model of liver injury. Con A administration resulted in liver injury, as shown by the increased transaminase plasma levels and liver DNA fragmentation, and caused spleen T-cell activation, which was associated with a strong increment in liver infiltrating T helper cells. Moreover, Con A injection leads to a marked increase in plasma tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) levels. Galectin-1 pretreatment dose-dependently prevented both liver injury and T-helper cell liver infiltration induced by Con A. In vivo and in vitro experiments indicated that the protective effects of galectin-1 depend on the selective elimination of Con A-activated T cells. In addition, galectin-1 almost completely prevented the Con A-induced increase in plasma TNF-alpha and IFN-gamma, an effect that was, at least in part, independent on the elimination of activated T helper cells, because galectin-1 prevented lipopolysaccharide (LPS)-induced release of TNF-alpha and IFN-gamma also from macrophages in vitro, without affecting their viability. The present study suggests that galectin-1 is potentially useful in the treatment of T-cell-mediated human liver disorders.

Topics: Adjuvants, Immunologic; Animals; Apoptosis; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Fas Ligand Protein; fas Receptor; Galectin 1; Hemagglutinins; Liver; Lymphocyte Activation; Macrophages; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Receptors, Interleukin-2; Spleen; T-Lymphocytes; Up-Regulation

The role of leptin was investigated in two models of T cell-mediated hepatitis: the administration of Con A or of Pseudomonas aeruginosa exotoxin A (PEA). In both models, leptin-deficient (ob/ob) mice were protected from liver damage and showed lower induction of tumor necrosis factor (TNF) alpha and IL-18 compared with their lean littermates. Neutralization of TNF-alpha reduced induction of IL-18 by either Con A (70% reduction) or PEA (40% reduction). Pretreatment of lean mice with either soluble TNF receptors or with an anti-IL-18 antiserum significantly reduced Con A- and PEA-induced liver damage. The simultaneous neutralization of TNF-alpha and IL-18 fully protected the mice against liver toxicity. However, neutralization of either IL-18 or TNF-alpha did not inhibit Con A-induced production of IFN-gamma. Thymus atrophy and alterations in the number of circulating lymphocytes and monocytes were observed in ob/ob mice. Exogenous leptin replacement restored the responsiveness of ob/ob mice to Con A and normalized their lymphocyte and monocyte populations. These results demonstrate that leptin deficiency leads to reduced production of TNF-alpha and IL-18 associated with reduced T cell-mediated hepatotoxicity. In addition, both TNF-alpha and IL-18 appear to be essential mediators of T cell-mediated liver injury.

Topics: ADP Ribose Transferases; Animals; Bacterial Toxins; Chemical and Drug Induced Liver Injury; Concanavalin A; Exotoxins; Female; Interleukin-18; Leptin; Liver; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Obese; Pseudomonas aeruginosa Exotoxin A; T-Lymphocytes; Tumor Necrosis Factor-alpha; Virulence Factors

Tumor necrosis factor (TNF) is a cytokine produced by macrophages and T lymphocytes that acts through two distinct receptors, TNFR1 (60 kD, CD120a) and TNFR2 (80 kD, CD120b), to affect cellular proliferation, differentiation, survival, and cell death. In addition to its proinflammatory actions in mucosal tissue, TNF is important for liver regeneration. Keratin 8 (K8) and keratin 18 (K18) form intermediate filaments characteristic of liver and other single cell layered, internal epithelia and their derivative cancers. K8-deficient (K8(-)) mice, which escape embryonic lethality, develop inflammatory colorectal hyperplasia, mild liver abnormalities, and tolerate hepatectomy poorly. We show that normal and malignant epithelial cells deficient in K8 and K18 are approximately 100 times more sensitive to TNF-induced death. K8 and K18 both bind the cytoplasmic domain of TNFR2 and moderate TNF-induced, Jun NH(2)-terminal kinase (JNK) intracellular signaling and NFkappaB activation. Furthermore, K8(-) and K18(-) mice are much more sensitive to TNF dependent, apoptotic liver damage induced by the injection of concanavalin A. This moderation of the effects of TNF may be the fundamental function of K8 and K18 common to liver regeneration, inflammatory bowel disease, hepatotoxin sensitivity, and the diagnostic, persistent expression of these keratins in many carcinomas.

Topics: Animals; Apoptosis; Cell Line; Chemical and Drug Induced Liver Injury; Concanavalin A; Epithelial Cells; Humans; JNK Mitogen-Activated Protein Kinases; Keratins; Liver; Mice; Mice, Knockout; Mitogen-Activated Protein Kinases; NF-kappa B; Protein Binding; Receptors, Tumor Necrosis Factor; Signal Transduction; Transfection; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

The demonstrated utility of the nucleoside analog ribavirin in the treatment of certain viral diseases can be ascribed to its multiple distinct properties. These properties may vary in relative importance in differing viral disease conditions and include the direct inhibition of viral replication, the promotion of T-cell-mediated immune responses via an enhanced type 1 cytokine response, and a reduction of circulating alanine aminotransferase (ALT) levels associated with hepatic injury. Ribavirin also has certain known toxicities, including the induction of anemia upon chronic administration. To determine if all these properties are linked, we compared the D-nucleoside ribavirin to its L-enantiomer (ICN 17261) with regard to these properties. Strong similarities were seen for these two compounds with respect to induction of type 1 cytokine bias in vitro, enhancement of type 1 cytokine responses in vivo, and the reduction of serum ALT levels in a murine hepatitis model. In contrast, ICN 17261 had no in vitro antiviral activity against a panel of RNA and DNA viruses, while ribavirin exhibited its characteristic activity profile. Importantly, the preliminary in vivo toxicology profile of ICN 17261 is significantly more favorable than that of ribavirin. Administration of 180 mg of ICN 17261 per kg of body weight to rats by oral gavage for 4 weeks generated substantial serum levels of drug but no observable clinical pathology, whereas equivalent doses of ribavirin induced a significant anemia and leukopenia. Thus, structural modification of ribavirin can dissociate its immunomodulatory properties from its antiviral and toxicologic properties, resulting in a compound (ICN 17261) with interesting therapeutic potential.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Antiviral Agents; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Hepatitis Viruses; HIV; Humans; Male; Mice; Mice, Inbred BALB C; Rats; Ribavirin; Stereoisomerism; T-Lymphocytes

Cytochrome P450 (CYP) gene expression in the livers of mice with concanavalin A-induced hepatitis was examined. Treatment of mice with concanavalin A (10 mg/kg, i.v.) elevated plasma alanine aminotransaminase activity. In normal liver, CYP1A2, 3A and 2E1 mRNAs were expressed, and concanavalin A treatment differentially suppressed the expression of these CYP genes. Gadolinium chloride (40 mg/kg, i.p.) treatment, which inhibited the concanavalin A-induced elevation of plasma alanine aminotransferase activity without affecting concanavalin A-induced cytokine expression, counteracted the concanavalin A-induced suppression of CYP gene expression in the liver. Kupffer cell function or hepatic injury might contribute to the concanavalin A-induced suppression of CYP gene expression.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytochrome P-450 Enzyme System; Female; Gadolinium; Gene Expression Regulation, Enzymologic; Liver; Mice; Mice, Inbred BALB C

The current therapy for hepatitis B and C is based on systemic administration of recombinant human alpha interferon (r-hIFN-alpha). However, systemic delivery of r-hIFN-alpha is associated with severe side effects, but more importantly, it is effective in only a small percentage of patients. In an effort to maximize IFN-alpha antiviral efficacy, we have explored the therapeutic potential of murine IFN-alpha2 (mIFNalpha2) selectively expressed in the liver. To this end, we have developed a helper-dependent adenovirus vector (HD) containing the mIFN-alpha2 gene under the control of the liver-specific transthyretin promoter (HD-IFN). Comparison with a first-generation adenovirus carrying the same mIFN-alpha2 expression cassette indicates that at certain HD-IFN doses, induction of antiviral genes can be achieved in the absence of detectable circulating mIFN-alpha2. Challenge of injected mice with mouse hepatitis virus type 3 showed that HD-IFN provides high liver protection. Moreover, liver protection was also observed in acute nonviral liver inflammation hepatitis induced by concanavalin A at 1 month postinfection. These results hold promise for the development of a gene therapy treatment for chronic viral hepatitis based on liver-restricted expression of IFN-alpha2.

Topics: Adenoviridae; Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Gene Expression; Genetic Therapy; Genetic Vectors; Helper Viruses; Hepatitis, Viral, Animal; Humans; Interferon-alpha; Liver; Mice; Mice, Inbred C57BL; Murine hepatitis virus

We have studied the effects of either exogenously-administered interferon (IFN-)gamma or of a nonimmunogenic mouse IFN-gamma receptor-Immunoglobulin (IFN-gamma R-Ig) fusion protein on the development of Concanavalin (Con)A-induced hepatitis in NMRI mice. PBS-treated control mice injected with 20 mg/kg ConA developed classical serological and histological signs of hepatitis with elevation of transaminases in the blood and infiltration of the liver by mononuclear cells and neutrophils. Treating the mice with rat IFN-gamma 24 h prior to and 1 h after ConA-challenge markedly exacerbated these signs of hepatitis in a dose-dependent fashion. Moreover, mice injected with lower, non hepatitogenic, doses of ConA (10, 5 mg/kg) became fully susceptible to develop hepatitis upon similar treatment with IFN-gamma. Concordantly, ConA-induced hepatitis was abrogated by either IFN-gamma R-Ig fusion protein or anti-IFN-gamma mAb. These data provide further evidence for the central pathogenetic role of endogenous IFN-gamma in ConA-induced hepatitis and demonstrate the feasibility to prevent disease development by means of a non immunogenic IFN-gamma R-Ig fusion protein.

Topics: Animals; Antibodies, Monoclonal; Chemical and Drug Induced Liver Injury; CHO Cells; Concanavalin A; Cricetinae; Cytokines; Immunoglobulins; Interferon gamma Receptor; Interferon-gamma; Interleukin-4; Liver; Male; Mice; Rats; Receptors, Interferon; Recombinant Fusion Proteins; T-Lymphocytes

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

Inchinko-to (TJ-135) is a herbal medicine consisting of three kinds of crude drugs, and in Japan it is administered mainly to patients with cholestasis. The present study evaluated the effects of TJ-135 on concanavalin A (con A)-induced hepatitis in mice in vivo and con A-induced cytokine production in vitro. When mice were pretreated with oral TJ-135 for 1 week before intravenous con A injection, the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) were significantly decreased 8 h after con A administration (-82%, -96% and -66% respectively). In histological investigations, sub-massive hepatic necrosis accompanying inflammatory cell infiltration was not observed in mice pretreated with TJ-135. Serum levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma) and IL-2 were significantly lower in mice pretreated with TJ-135 compared with controls, while IL-10 levels were higher in these mice. Intrasplenic IL-12 levels were significantly lower in mice pretreated with TJ-135, while intrasplenic IL-10 levels were higher in these mice. In vitro, IL-10 production by splenocytes was increased by the addition of TJ-135 to the culture medium, whereas the production of IL-12 and IFN-gamma was inhibited. These results suggest that con A-induced hepatitis was ameliorated by pretreatment with TJ-135. With regard to the mechanism of these effects of TJ-135, we speculate that TJ-135 inhibits the production of inflammatory cytokine and enhances the production of anti-inflammatory cytokines. Therefore administration of TJ-135 may be useful in patients with severe acute hepatitis accompanying cholestasis or in those with autoimmune hepatitis.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-2; Japan; L-Lactate Dehydrogenase; Male; Medicine, East Asian Traditional; Mice; Mice, Inbred ICR; Plant Lectins; Plants, Medicinal

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

Rolipram is a type IV phosphodiesterase inhibitor endowed with powerful immunomodulatory properties. In this study, we evaluated the effects of this drug on the development of the T-cell-mediated hepatitis inducible in mice by concanavalin A. The results indicated that prophylactic treatment with either 5 or 10 mg/kg rolipram injected intraperitoneally 24 h and 1 h prior to intravenous (i.v.) challenge with 20 mg/kg concanavalin A successfully ameliorated serological and histological signs of liver damage, so that the treated mice showed lower transaminase levels in the plasma and milder mononuclear cell infiltration of the liver as compared to vehicle-treated controls. Moreover, this effect was associated with profound modifications of circulating levels of cytokines released after concanavalin A injection, with the blood levels of interferon-gamma and tumor necrosis factor-alpha being significantly lower and those of interleukin-10 higher than those of the control mice. In particular, the increased blood levels of interleukin-10 might play an important role in the anti-hepatitic effects of rolipram as coadministering this compound with anti-interleukin-10 monoclonal antibody significantly reduced its anti-inflammatory action. These results suggest that rolipram may be useful in the clinical setting for the treatment of cell-mediated immunoinflammatory diseases such as immunoinflammatory hepatitis.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Monoclonal; Cell Movement; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Interleukin-10; Leukocytes, Mononuclear; Male; Mice; Phosphodiesterase Inhibitors; Pyrrolidinones; Rolipram; T-Lymphocytes; Transaminases

Liver natural killer 1.1 antigen (NK1)+ T cells and IL-4 play a crucial role in concanavalin-A (Con-A)-induced hepatic injury in mice, and a T helper (Th) 2 immune response was thus suggested to be involved. This study was designed to examine the effect of bacterial lipopolysaccharide (LPS), a strong inducer of a Th 1 immune response, on Con-A hepatic injury and also to clarify further the cytokine milieu of Con-A hepatitis.. LPS were injected into mice before Con-A injection to evaluate the effect on hepatic injury. The effect of the pretreatment with various T1 and Th2 cytokines or anti-cytokine antibodies on Con-A hepatitis was also examined.. LPS in quantities > or = 500 ng/mouse, when injected 24 h before Con-A injection, abrogated the Con-A-induced elevation of transaminases, hepatocyte destruction and serum IL-4 elevation. This LPS inhibitory effect was blocked when the mice were injected with either anti-IL-6 antibody before LPS injection or IL-4 before Con-A injection. IL-6, but neither IL-10 nor IL-12 pretreatment suppressed Con-A-induced IL-4 production and hepatitis. NK1+ T cells produced IL-4 while both NK1+ T cells and NK1- T cells produced IFN-gamma. Not only anti-IL-4 antibody but also the anti-IFN-gamma antibody pretreatment inhibited Con-A hepatitis. However, although the anti-IL4 antibody suppressed IL-4 alone, the anti-IFN-gamma Ab unexpectedly inhibited both IFN-gamma and IL-4 elevation, while IL-4 injection evoked a moderate Con-A hepatitis even in the anti-IFN-gamma antibody-treated mice. Furthermore, the IL-4 mutant mice did not develop Con-A hepatitis.. LPS inhibited Con-A hepatitis by inducing IL-6 and thereby inhibited IL-4 synthesis from NK1+ T cells. Although both IL-4 and IFN-gamma were required for the full induction of Con-A hepatic injury, exogenous IL-4 evoked a moderate Con-A hepatitis, even in the absence of IFN-gamma.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interleukin-10; Interleukin-12; Interleukin-4; Interleukin-6; Killer Cells, Natural; Lipopolysaccharides; Liver; Male; Mice; Mice, Inbred C57BL; Receptors, Interleukin-2; Th1 Cells

Recombinant human interleukin-11 (rhIL-11) is a multifunctional cytokine that can reduce inflammation through the downregulation of multiple pro-inflammatory mediators from activated macrophages. rhIL-11 also inhibits production of several immunostimulatory cytokines such as IL-12 and interferon gamma (IFN-gamma) and has shown biological activity in multiple animal models of inflammatory disease consistent with immunomodulatory effects on macrophages and T cells. To further elucidate the anti-inflammatory activity of rhIL-11 in vivo, the effect of rhIL-11 in a model of Concanavalin A (Con-A)-induced T-cell-mediated hepatotoxicity was examined. Administration of a single dose of rhIL-11 before Con-A administration reduced centrilobular liver necrosis and enhanced survival. A dose-dependent reduction in serum levels of liver enzymes, tumor necrosis factor alpha (TNF-alpha), and IFN-gamma corresponded with this amelioration of liver damage. No significant change in infiltrating lymphocyte populations in the liver was observed following rhIL-11 treatment. Taken together, these results indicate that rhIL-11 ameliorates T-cell-mediated hepatic injury and suggests its therapeutic potential to treat inflammatory liver disease.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Dose-Response Relationship, Drug; Enzyme Induction; Female; Humans; Interferon-gamma; Interleukin-11; Interleukin-2; Liver; Mice; Mice, Inbred BALB C; Necrosis; Recombinant Proteins; T-Lymphocytes; Tumor Necrosis Factor-alpha

One single intra-venous (i.v.) injection of Concanavalin A (Con A) into mice provokes a cell-mediated immunoinflammatory hepatitis. We have presently evaluated the immunopharmacological effects of exogenous interleukin (IL)-10 and the role of endogenous IL-10 in this model by using exogenous IL-10, anti-IL-10 monoclonal antibody (mAb) and mice with disrupted IL-10 gene (IL-10 KO mice). Whilst exogenous IL-10 administered in a prophylactic (1 h prior to Con A) and even "early" therapeutic fashion (30 min after Con A) reduced the elevation of transaminase activities in plasma in a dose-dependent manner, observed in control mice, these biochemical markers of liver injury were significantly increased both in IL-10 KO mice as well as in those receiving anti-IL-10 mAb. Interestingly, doses of Con A lower than 20 mg/kg that were only capable of inducing slight serological signs of hepatitis in mice, exerted marked hepatitic effects when administered to either anti-IL-10 mAb-treated mice or to IL-10 KO mice. The disease modulating effects of exogenous IL-10 and either genetical or pharmacologically-induced IL-10 deficiency were associated with profound and opposite modifications of the Con A-induced increase in the circulating levels of IFN-gamma and TNF-alpha. Relative to control animals, the blood levels of these cytokines were diminished in IL-10-treated mice and augmented in both IL-10 KO mice and anti-IL-10 mAb-treated mice. These results prove the physiological antiinflammatory role of endogenous IL-10 in Con A induced hepatitis and the beneficial effects of IL-10 treatment to prevent this condition.

Topics: Alanine Transaminase; Animals; Antibodies, Monoclonal; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-10; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Time Factors; Tumor Necrosis Factor-alpha

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

A single intravenous injection of concanavalin A (Con A) induces T-cell activation-associated inflammatory injury selectively in the liver. This study investigated the strain difference in the development of Con A-induced hepatic injury. Normal C57BL/6 and BALB/c spleen cells produced comparable levels of T-cell-derived lymphokines (interferon gamma [IFN-gamma], tumor necrosis factor alpha [TNF-alpha], and interleukin-2 [IL-2]) following in vitro stimulation with Con A. A single intravenous injection of Con A to C57BL/6 mice induced the plasma levels of TNF-alpha and IL-2 comparable with or slightly higher than those observed in BALB/c mice, whereas the same treatment resulted in an apparently lower level of IFN-gamma production in C57BL/6 mice. RNA from livers of Con A-treated C57BL/6 mice exhibited lower levels of IFN-gamma mRNA than RNA of BALB/c livers. Unexpectedly, a dramatic difference in the severity of hepatic injury was observed between C57BL/6 and BALB/c. Namely, the peak alanine transaminase (ALT) level was more than 15,000 U/L and inducible as early as 8 hours after injection of 0.2 mg Con A per mouse in the C57BL/6 strain, whereas the peak was approximately 3,000 U/L and induced as late as 24 hours after Con A injection in the BALB/c strain. The increase in plasma ALT levels was limited to less than 10% by injection of anti-IFN-gamma monoclonal antibody (mAb) in both strains. The C57BL/6 strain inducing lower levels of IFN-gamma exhibited higher IFN-gamma responsiveness as exemplified by the intrahepatic expression of an IFN-gamma-inducible gene, an inducible type of nitric oxide (NO) synthase (iNOS). These results indicate that, while IFN-gamma produced in vivo by activated T cells induces hepatic injury, there exists a striking strain difference in the induction of IFN-gamma-dependent hepatic injury.

Topics: Alanine Transaminase; Animals; Cells, Cultured; Chemical and Drug Induced Liver Injury; Concanavalin A; Female; Gene Expression; Genetic Variation; Interferon-gamma; Interleukin-2; Liver; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; RNA, Messenger; Spleen; Tumor Necrosis Factor-alpha

Apoptosis is a physiologic process that serves to eliminate cells during development or in response to immunologic regulation. In acute inflammation, however, apoptosis triggered by the overproduction of "death factors" such as TNF-alpha or Fas ligand (FasL) may contribute to tissue injury. Both TNF-alpha and FasL are presumed to convey an apoptotic signal by activating a cascade of cysteine-aspartate proteases, which includes IL-1beta-converting enzyme or caspase-1. In the present study, we evaluated the contribution of TNF-alpha and FasL, as well as the role of caspase-1, in Con A-induced hepatitis. We report here that TNF-alpha and FasL mRNA and protein levels are both increased in the livers of Con A-challenged mice. Using a novel inhibitor of TNF-alpha, we can confirm that Con A-induced hepatitis is primarily TNF-alpha dependent. Blockade of FasL with a soluble Fas immunoadhesin does not prevent liver injury in animals treated with Con A alone. However, administration of a matrix metalloproteinase inhibitor exacerbates liver injury, in part through a FasL-dependent process, since pretreatment with the soluble Fas immunoadhesin reduces liver injury in this model. In addition, mice lacking functional caspase-1 are resistant to Con A-induced hepatitis, even after pretreatment with a matrix metalloproteinase inhibitor. We conclude that TNF-alpha plays a predominant role in Con A-induced liver injury, although concomitant activation of FasL can also lead to apoptotic injury. Furthermore, Con A-induced hepatitis is caspase-1 dependent.

Topics: Animals; Apoptosis; Base Sequence; Caspase 1; Chemical and Drug Induced Liver Injury; Concanavalin A; Cysteine Endopeptidases; DNA Primers; Fas Ligand Protein; Liver; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Polymerase Chain Reaction; RNA, Messenger; Tumor Necrosis Factor-alpha; Up-Regulation

The liver injury in the concanavalin A (Con A)-induced mouse hepatitis model has been well studied. However, there has been little study on the effects of Con A on extrahepatic organs. The aim of the present work was to determine the effects of Con A on the spleen, kidney and lung. A histopathological study showed that Con A (15 mg/kg, i.v.) administration affects not only the liver, but also all these extrahepatic organs. Messenger RNA expression was studied by the using polymerase chain reaction. Treatment with Con A induced interleukin-2 mRNA in the spleen, but only slightly induced it in the kidney. The mRNAs of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) were induced in all these organs. At 24 hr after Con A treatment, the expression of IFN-gamma mRNA, but not that of TNF-alpha mRNA, was inhibited by cyclosporine A (50 mg/kg, i.p.), suggesting that Con A induced these cytokine mRNAs through different mechanisms. In the kidney and lung, CD4+ and CD8+ T-cell infiltration was suggested by the Con A-induced CD4 and CD8 mRNAs. The present study showed the histopathological effects of Con A and Con A-induced cytokine mRNA expression on the spleen, kidney and lung.

Topics: Animals; CD4 Antigens; CD8 Antigens; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclosporine; Cytokines; Disease Models, Animal; Female; Liver; Lung; Mice; Mice, Inbred BALB C; RNA, Messenger; Spleen

The objective of the present study was to determine the effects of concanavalin A (Con A) administration on the interleukin 1beta converting enzyme (ICE) activity and CPP32-like activity in mouse liver. Treatment with Con A (0.2 mg/mouse, i.v.) caused an elevated plasma alanine aminotransferase (ALT) level at 8 hr after Con A injection. ICE activity was decreased at 8 and 24 hr after Con A treatment. In contrast, CPP32-like activity was increased at 24 hr after Con A injection. Since CPP32-like activity was induced after ALT had increased, the induction of CPP32-like activity may not be involved in Con A-induced hepatitis.

Topics: Amino Acid Chloromethyl Ketones; Animals; Caspase 1; Caspase 3; Caspases; Chemical and Drug Induced Liver Injury; Concanavalin A; Cysteine Proteinase Inhibitors; Disease Models, Animal; Enzyme Induction; Female; Liver; Mice; Mice, Inbred BALB C

Treatment of mice with concanavalin A (Con A) induced interleukin-2 (IL-2) mRNA expression in the liver, which might be a result of Con A-induced T-cell activation. Pretreatment with cyclosporine A (CsA) (50 mg/kg, i.p.) or dexamethasone (DEX) (2.5 mg/kg, i.p.) inhibited the Con A-induced liver injury, as assessed by the plasma alanine aminotransferase level, by 85% and 95%, respectively. CsA inhibited the Con A-induced IL-2 mRNA expression completely, whereas DEX only partially inhibited it. Thus CsA seems to prevent Con A-induced hepatitis mainly by inhibiting T-cell activation. In the case of DEX, rather than by inhibiting Con A-induced T-cell activation, it may prevent Con A-induced hepatitis through other means.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Cyclosporine; Dexamethasone; Female; Gene Expression Regulation; Immunosuppressive Agents; Interleukin-2; Liver; Mice; Mice, Inbred BALB C; RNA, Messenger

Propagermanium (3-oxygermylpropionic acid polymer) is an organic germanium compound that activates the immune system. In this study, we investigated the action of propagermanium on T-cell-mediated murine hepatic injury induced by concanavalin A (Con A). Oral administration of propagermanium inhibited the development of liver injury about 10 h after ConA injection. Histological analysis demonstrated that propagermanium attenuated the extent of liver damage compared with controls, reducing infiltration by leucocytes, especially CD11b-positive cells. Infiltration by CD4-positive cells was not affected. Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma are crucial for the development of hepatitis in this model. Propagermanium treatment induced significant inhibition of subsequent TNF-alpha production about 10 h after Con A injection, without affecting IFN-gamma, interleukin (IL)-10, IL-4 and IL-12 production. This effect on TNF-production coincided with the inhibition of aminotransferase activity late in the progression of Con A-induced liver injury. These facts suggest that this compound affects the macrophages (Mphi) function in the liver sinusoid. Therefore, Mphi were cultured with liver sinusoidal endothelial cells (SEC) and the effect of propagermanium on TNF-alpha production in the presence of IFN-gamma was determined. TNF-alpha production was reduced significantly in the coculture of Mphi and SEC when Mphi was treated with propagermanium. These results might explain the mechanisms by which propagermanium inhibits Con-A-induced liver injury. That is, propagermanium improves hepatitis through mechanisms including the reduced production of TNF-alpha, without modification of Th1- and Th2-cell function.

Topics: Animals; Antibodies; Cells, Cultured; Chemical and Drug Induced Liver Injury; Coculture Techniques; Concanavalin A; Endothelium, Vascular; Female; Germanium; Interferon Inducers; Interferon-gamma; Liver; Macrophages; Mice; Mice, Inbred BALB C; Organometallic Compounds; Propionates; Rats; Rats, Inbred F344; Tumor Necrosis Factor-alpha

TNF-alpha is a pleiotropic cytokine that exists both as a 26-kDa cell-associated and a 17-kDa soluble form. Recently, a class of matrix metalloproteinase inhibitors has been identified that can prevent the processing by TNF convertase of 26-kDa TNF-alpha to its 17-kDa form and can reduce mortality from normally lethal doses of D-galactosamine plus LPS (D-GalN/LPS). Here we report that a matrix metalloproteinase inhibitor, GM-6001, improves survival but does not protect against liver injury from D-GalN/LPS-induced shock in the mouse. In Con A-induced hepatitis, GM-6001 actually exacerbates hepatocellular necrosis and apoptosis despite greater than 90% reduction in plasma TNF-alpha concentrations. Treatment with GM-6001 also has minimal effect on the concentration of membrane-associated TNF-alpha in the livers of animals with Con A induced hepatitis. In contrast, a TNF binding protein (TNF-bp), which neutralizes both membrane-associated and soluble TNF-alpha, prevents D-GalN/LPS- and Con A-induced hepatitis. Our studies suggest that cell-associated TNF-alpha plays a role in the hepatocellular necrosis and apoptosis that accompany D-GalN/LPS- or Con A-induced hepatitis, and that matrix metalloproteinase inhibitors are ineffective in preventing this hepatic injury.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Dipeptides; Drug Synergism; Galactosamine; Lipopolysaccharides; Liver; Metalloendopeptidases; Mice; Mice, Inbred C57BL; Protease Inhibitors; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha

Experimental T-cell-mediated hepatitis induced by concanavalin A (Con A) involves the production of proinflammatory cytokines. Because interleukin (IL)-10 is a potent anti-inflammatory cytokine derived from macrophages and T cells and is produced within the liver, we investigated the role of IL-10 in modulating the hepatotoxicity and the secretion of cytokines following in vivo injection of Con A. IL-10 is produced early in the serum after Con A challenge. Neutralization of endogenous IL-10 by monoclonal antibodies (mAbs) increases the secretion of tumor necrosis factor alpha (TNF-alpha) (+111%), interferon gamma (IFN-gamma) (+92%), and IL-12 (+730%) 8 hours after Con A injection, and increases the hepatotoxicity, assessed by serum alanine transaminase (ALT) (+174%) measurement and by histology, 24 hours after induction of hepatitis. Conversely, preadministration of recombinant IL-10 reduces the production of these proinflammatory cytokines (-47%, -80%, and -47% for TNF-alpha, IL-12, and IFN-gamma, respectively), and decreases neutrophil infiltration and ALT serum concentration (-74%) 8 hours after Con A challenge. We conclude that IL-10, either endogenously produced or exogenously added, has a hepatoprotective role in Con A-induced hepatitis, through its suppressive property on proinflammatory cytokine production, and that it might be of therapeutic relevance in human liver diseases involving activated T cells.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Interferon-gamma; Interleukin-10; Interleukin-12; Liver; Mice; Mice, Inbred C3H; Necrosis; Recombinant Proteins; Tumor Necrosis Factor-alpha

Previous studies have shown that the administration of concanavalin A (ConA) into mice induces immune-mediated liver injury, which can be largely abrogated by neutralizing tumor necrosis factor(TNF)alpha. Vesnarinone is an experimental drug which is known to inhibit TNF alpha release. Here we demonstrate that vesnarinone inhibits ConA-induced hepatic injury. In a dose-dependent manner, vesnarinone inhibits in several mouse strains the increase of serum aminotransferase concentrations. additional experiments show that vesnarinone inhibits ConA-mediated accumulation of DNA fragmentation in the liver. Furthermore, the drug significantly reduces the levels of circulating TNF alpha and interleukin-6 (IL-6). Vesnarinone does not modulate TNF alpha and IL-6 action on hepatic cells, as shown by its failure to reduce the cytokine specific-stimulation of acute phase plasma proteins in the rat hepatoma H-35 cell line. Neither vesnarinone nor anti-TNF alpha protect against direct liver injury induced by a sublethal dose of agonist anti-Fas (CD95) antibody. Taken together, these results suggest that vesnarinone blocks hepatic injury, in part by inhibiting the release of TNF alpha in vivo.

Topics: Acute-Phase Reaction; Animals; Antibodies, Monoclonal; Autoimmune Diseases; Chemical and Drug Induced Liver Injury; Concanavalin A; fas Receptor; Liver Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pyrazines; Quinolines; Rats; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

The effects of concanavalin A (Con A) on liver cytokine gene expression was studied in mice. The CD4 mRNA expression in normal liver suggests the presence of CD4+ T cells. The administration of Con A induced interleukin (IL)-1beta, IL-2 and IL-2 receptor mRNAs, which implies lymphocyte activation in the liver. Interferon-gamma and tumor necrosis factor-alpha mRNA expressions were increased gradually. The present results showed that Con A induced liver cytokine genes. This cytokine gene induction might have been the result of lymphocyte activation in the liver.

Topics: Animals; CD4 Antigens; Chemical and Drug Induced Liver Injury; Concanavalin A; Cytokines; Female; Liver; Mice; Mice, Inbred BALB C; RNA, Messenger; T-Lymphocytes

Concanavalin A (ConA) activates T lymphocytes and causes T-cell mediated hepatic injury in mice. The intravenous administration of human immunoglobulins has beneficial effects in T-cell mediated diseases such as experimental autoimmune encephalomyelitis and adjuvant arthritis. In the present study, we examined the effects of intravenous immunoglobulins in a mouse model of T-cell mediated, acute liver injury induced by concanavalin A. Balb/c mice were inoculated with 12 mg/kg concanavalin A with or without intravenous immunoglobulins at doses of 0.4, 0.6, 0.8 g/kg body wt. The serum levels of liver enzymes, tumor necrosis factor-alpha, interferon-gamma and interleukin-6 were assayed 2, 6 and 24 h after concanavalin A administration. Intravenous immunoglobulins did not prevent concanavalin A-induced hepatitis, as manifested by elevation of serum aminotransferases and histopathological evaluation. The serum levels of tumor necrosis factor-alpha in mice pretreated with immunoglobulins, measured 2 h after ConA treatment were reduced, while interferon-gamma levels measured 6 h after ConA inoculation were 5-fold higher than control levels. There was no effect of intravenous immunoglobulins on the release of interleukin 6. In conclusion, these results indicate that intravenous immunoglobulin is not effective in preventing T-cell mediated concanavalin A-induced hepatitis. The increased secretion of interferon-gamma and the incomplete suppression of tumor necrosis factor-alpha release may explain the lack of efficacy of intravenous immunoglobulin in this experimental model.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Humans; Immunoglobulins, Intravenous; Interferon-gamma; Interleukin-6; Liver; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; T-Lymphocytes; Transaminases; Tumor Necrosis Factor-alpha

T cell-dependent liver injury involving endogenous tumor necrosis factor (TNF) alpha can be induced by either concanavalin A in naive mice or by activating anti-CD3 antibody or staphylococcal enterotoxin B in D-galactosamine-sensitized mice. In this study, the role of interferon gamma (IFN-gamma) in these T-cell models was addressed.. Mice were pretreated with a neutralizing anti-mouse IFN-gamma antiserum before injection of T cell-activating agents. Plasma cytokine and transaminase levels were determined. Apoptotic cell death was assessed by hepatic DNA fragmentation.. Anti-IFN-gamma antiserum significantly protected mice from concanavalin A-induced liver injury. Circulating IFN-gamma was completely suppressed, and TNF was reduced by 50%. Recombinant TNF-alpha administered to mice treated with concanavalin A and anti-IFN-gamma antiserum failed to initiate liver injury. Similar results were obtained with recombinant IFN-gamma in concanavalin A-challenged mice under the condition of TNF neutralization. Neither hepatic DNA fragmentation nor release of transaminases was inhibited by anti-IFN-gamma antiserum when liver injury was induced by staphylococcal enterotoxin B or anti-CD3 antibody in D-galactosamine-sensitized mice.. Both TNF as well as IFN-gamma are critical mediators of liver injury in concanavalin A-treated mice, whereas hepatic DNA fragmentation and liver failure in the D-galactosamine models depend only on TNF.

Topics: Animals; Apoptosis; Chemical and Drug Induced Liver Injury; Concanavalin A; DNA Damage; Enterotoxins; Enzyme-Linked Immunosorbent Assay; Galactosamine; Immune Sera; Interferon-gamma; Liver; Liver Failure; Lymphocyte Activation; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Recombinant Proteins; T-Lymphocytes; Transaminases; Tumor Necrosis Factor-alpha

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

The therapeutic efficacy of type I interferon (IFN) has been reported to vary considerably in different indications. The use of the cytokine as adjuvant therapy has been suggested to enhance its efficacy and reduce the toxicity frequently associated with long-term and high-dose administration. In this study, we have assessed the activity of type I IFN in the protection against and treatment of acute hepatitis induced in mice by the administration of concanavalin-A (ConA). At the same time, we have evaluated the efficacy of the synthetic immunomodulator murabutide when administered alone or in combination with type I IFN to protect against ConA hepatitis and in the treatment of tumors in MethA sarcoma-bearing mice. Our results demonstrate a prophylactic effect as well therapeutic effects of type I IFN and of murabutide in the inflammation-mediated model of liver damage. The use of combination therapy presented enhanced efficacy in inhibiting the ConA-induced elevation of plasma transaminases. Both compounds were found to suppress IFN-gamma mRNA accumulation in the livers of ConA treated mice. This activity is discussed with respect to the mechanism of action of the two immunomodulators. In addition, the combination of murabutide with type I IFN exhibited synergistic antitumor activity that was clearly seen in the significant regression of MethA tumors and resulted in almost 50 percent tumor-free mice. The potential clinical application of combination therapies using a cytokine and a safe immunomodulator is analyzed in terms of enhancing the cytokine efficacy and extending its use to new indications.

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Adjuvants, Immunologic; Alanine Transaminase; Animals; Anti-Inflammatory Agents; Antiviral Agents; Aspartate Aminotransferases; Chemical and Drug Induced Liver Injury; Concanavalin A; Drug Evaluation, Preclinical; Drug Screening Assays, Antitumor; Drug Synergism; Drug Therapy, Combination; Female; Interferon Type I; Mice; Mice, Inbred BALB C

Male NMRI or BALB/c mice developed severe liver injury as assessed by transaminase release within 8 h when an intravenous dose greater than 1.5 mg/kg concanavalin A (Con A) was given. Histopathologically, only the liver was affected. Electron micrographs revealed leukocyte sticking to endothelial cells and bleb formation of hepatocytes. The hepatotoxicity of the lectin correlated neither with its agglutination activity nor with its sugar specificity. Administration of 0.5 mg/kg dexamethasone or 50 mg/kg cyclosporine A or 50 mg/kg FK 506 (Fujimycin) resulted in protection of the animals whereas indomethacin pretreatment failed to protect. Con A hepatitis was accompanied by the release of IL-2 into the serum of the animals. Mice with severe combined immunodeficiency syndrome lacking B as well as T lymphocytes were resistant against Con A. Athymic nude mice with immature T lymphocytes were also resistant. Pretreatment of mice with an antibody against T lymphocytes fully protected against Con A as did monoclonal anti-mouse CD4. Monoclonal anti-mouse CD8 failed to protect. Pretreatment of mice with silica particles, i.e., deletion of macrophages, prevented the induction of hepatitis. These findings provide evidence that Con A-induced liver injury depends on the activation of T lymphocytes by macrophages in the presence of Con A. The model might allow the study of the pathophysiology of immunologically mediated hepatic disorders such as autoimmune chronic active hepatitis.

Topics: Animals; Binding Sites; Carbohydrate Metabolism; Chemical and Drug Induced Liver Injury; Concanavalin A; Dose-Response Relationship, Drug; Interleukin-2; Liver; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C3H; T-Lymphocytes; Tumor Necrosis Factor-alpha

The effect of D-galactosamine on the structure of the glycan moiety of alpha 1-acid glycoprotein was studied throughout a nine days experiment. It was shown that: D-galactosamine led to an alteration of the Concanavalin A crossed immunoelectrophoresis pattern and to a decreased sialic acid content of alpha 1-acid glycoprotein. The undersialylation of alpha 1-acid glycoprotein was not linked to a change in the relative ratio of various Concanavalin A forms. At the end of the experiment (9 days after galactosamine injection), the Concanavalin A non-reactive forms of alpha 1-acid glycoprotein remained elevated whereas alanine transaminase activity, total protein and alpha-acid glycoprotein had returned to a control level. D-galactosamine-treated rats seem to be a suitable model for the study of the very fast cyclic modulations of the synthesis of the glycan moiety of glycoproteins.

Topics: Animals; Chemical and Drug Induced Liver Injury; Concanavalin A; Disease Models, Animal; Galactosamine; Immunoelectrophoresis, Two-Dimensional; Male; Oligosaccharides; Orosomucoid; Rats; Rats, Inbred Strains; Sialic Acids; Time Factors

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

1. Thioctic acid used clinically in poisoning by A. phalloides, protected perfused livers and also isolated hepatocytes against phalloidin, when given in high concentrations. 2. Some SH-compounds like coenzyme A, dimercaprol, cysteine and cysteamine were found to be protective in different concentrations. 3. Rifampicin protects mice against lethal doses of phalloidin, and inhibits poisoning of isolated hepatocytes at low concentrations. 4. Some choleretic drugs like dehydrocholate, temoebilin (extr. cucumae xanth.), ethacrynic acid influenced phalloidin poisoning by inhibition of binding. 5. Doses of 0.2 to 4.0 mg dexamethasone added to 100 ml of perfusion medium did not protect perfused rat livers against 0.5 mg phalloidin. 6. Pretreatment of female rats with estrogens effected protection against phalloidin in vivo. The same procedure resulted in moderate decrease of phalloidin effects when the livers of pretreated animals were poisoned in vitro. In male rats estrogen pretreatment was less effective. Castration did not augment the protective effect. 7. Secophalloidin, a biologically inactive derivative, did not influence phalloidin poisoning in perfused livers, even when applied in excessive concentrations. 8. Concanavalin A, probably bound in the neighborhood of binding sites for phalloidin, did not protect perfused livers against phalloidin. 9 Diethyldithiocarbamate, a compound protecting livers against carbon tetrachloride and halothane, was ineffective in phalloidin poisoning. 10. Further protective actions of Evans blue, of some phenanthrolines and of EDTA are discussed. 11. Pretreatment of animals with hepatotoxic compounds (CCl4, CHCl3, cinchophen) decreased the toxicity of phalloidin in vivo. Possible mechanisms are discussed.

Topics: Animals; Chelating Agents; Chemical and Drug Induced Liver Injury; Chloroform; Cholagogues and Choleretics; Coenzyme A; Concanavalin A; Cysteamine; Cysteine; Dexamethasone; Dimercaprol; Estradiol; Female; Male; Oligopeptides; Phalloidine; Rats; Rifampin; Sulfhydryl Compounds; Thioctic Acid

Topics: Animals; Blood Vessels; Chemical and Drug Induced Liver Injury; Concanavalin A; Inflammation; Injections, Intravenous; Liver; Lymphoid Tissue; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Inbred DBA; Spleen; Thymus Gland; Time Factors