concanavalin-a and Hepatitis

This review addresses the issue of histone deacetylase (HDAC) inhibitors as developed for the treatment of cancer and for the investigation of the inhibition of inflammation. The review focuses on both in vitro and in vivo models of inflammation and autoimmunity. Of particular interest is the inhibition of pro-inflammatory cytokines. Although the reduction in cytokines appears paradoxical at first, upon examination, some genes that are anti-inflammatory are upregulated by inhibition of HDAC. Whether skin diseases will be affected by inhibitors of HDAC remains to be tested.

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Concanavalin A; Cytokines; Disease Models, Animal; Enzyme Inhibitors; Genes, Viral; Graft vs Host Disease; Hepatitis; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Inflammation; Interleukin-1; Lipopolysaccharides

Peripheral T cells from patients with chronic active hepatitis (CAH) showed a significantly decreased suppressor effect (or increased helper effect) on allogeneic B cell differentiation into Ig-producing cells (Ig-PC) (p less than 0.05). After irradiation of T cells to eliminate suppressor influences, mean spontaneous helper activity of CAH was not different from that of healthy subjects, indicating that spontaneous helper activity of CAH was normal. Concanavalin A (Con A)-induced suppressor cell activity was significantly decreased in CAH (p less than 0.01, 9 defective cases out of 18 patients). Minor defect of Con A-induced suppressor activity was also found in some patients with chronic persistent hepatitis (CPH) (2 defective cases out of 14 patients). Autologous mixed lymphocyte reaction (AMLR) was significantly decreased in patients with CAH (p less than 0.005). Spontaneous suppressor or Con A-induced suppressor activity was not different statistically between HBsAg-positive and HBsAg-negative cases. Finally, we demonstrated a presence of a serum factor(s) that can decrease Con A-induced suppressor cell function of healthy subjects in 7 of 21 patients with CAH and 2 of 14 CPH. Our results suggest that defective suppressor cell function likely attributable to serum factor(s) may reflect altered immune responses of CAH.

Topics: B-Lymphocytes; Cell Differentiation; Chronic Disease; Concanavalin A; Female; Hepatitis; Humans; In Vitro Techniques; Lymphocyte Culture Test, Mixed; Male; T-Lymphocytes; T-Lymphocytes, Regulatory

Concanavalin A (Con A) affinity electrophoresis of serum alpha-fetoprotein (AFP) can distinguish hepatocellular carcinoma (HCC) from other malignancies when the serum AFP concentration is elevated. However, Con A has not been able to distinguish HCC from benign chronic liver disease such as cirrhosis or chronic hepatitis.. The Con A affinity electrophoresis of serum AFP was analyzed in patients with a serum AFP concentration greater than 50 ng/mL by antibody affinity electrophoresis and Western blotting in an attempt to distinguish hepatocellular carcinoma from benign chronic liver disease. Before the assay, the serum AFP concentrations were adjusted between 100 ng/ml and 300 ng/ml by concentrating or diluting the samples.. Of 180 patients with HCC, 44 (24%) had a single band and 91 (51%), 35 (19%), and 10 (6%) had 2, 3, and 4 bands, respectively. All 35 patients with chronic hepatitis had a single band. All but 1 of 72 patients with cirrhosis had a single band. Multiple AFP bands on Con A affinity electrophoresis appear to be diagnostic of HCC. This method has a sensitivity of 76%, a specificity of 99%, a positive predictive value of 99%, and a negative predictive value of 71% for detecting HCC. The number of AFP bands correlated with serum AFP concentration and tumor size in patients with HCC.. This assay is useful for distinguishing HCC from benign chronic liver diseases.

Topics: Adult; Aged; alpha-Fetoproteins; Blotting, Western; Carcinoma, Hepatocellular; Chi-Square Distribution; Chronic Disease; Concanavalin A; Diagnosis, Differential; Electrophoresis; Female; Hepatitis; Humans; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity

Eriocephalus africanus infusion is used as a diuretic and a diaphoretic and is also used in the treatment of gastrointestinal disorders and gynaecological conditions, inflammation and dermal disorders, asthma, coughs, fevers, and painful ailments. The plant has been used traditionally as a medication to cure inflammation and skin problems.. Studying E. africanus essential oil (EAEO) as a potential hepatoprotective measure against concanavalin (Con) A-induced hepatitis in mice and investigating its underlying mechanism.. Hydro-distilled oil of the fresh plant aerial shoots is subjected to GC/MS analysis. Autoimmune hepatitis (AIH) was induced in mice by intravenous injection of Con A (15 mg/kg). EAEO was administered orally before Con A injection to test its hepatoprotective activity.. GC/MS analysis revealed the presence of 22 compounds representing 99.43% of the oil components. The monoterpene artemisia ketone (41.02%) and the sesquiterpene juniper camphor (14.17%) are the major components. The in vivo study showed that the oil suppressed Con A-induced neutrophil and CD4+T cell infiltration into the liver, restored hepatic redox balance, inhibited Con A-induced elevation of tumor necrosis factor-alpha (TNF-α), interleukin (IL-6), and interferon-gamma (IFN-γ) hepatic levels which were correlated with its ability to suppress nuclear factor kappa B (NF-κB) and Signal Transducer and Activator of Transcription (STAT1) activation in the liver.. EAEO showed hepatoprotective potential against Con A-induced hepatitis in mice collectively through selective anti-oxidant, anti-inflammatory, and anti-necrotic effects.

Topics: Animals; Concanavalin A; Cytokines; Hepatitis; Inflammation; Liver; Mice; NF-kappa B; Oils, Volatile; Signal Transduction; Tumor Necrosis Factor-alpha

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

As a kind of mesenchymal-like stromal cells, endometrial regenerative cells (ERCs) have been demonstrated effective in the treatment of Concanavalin A (Con A)-induced hepatitis. However, the therapeutic mechanism of ERCs is not fully understood. Ecto-5`-nucleotidase (CD73), an enzyme that could convert immune-stimulative adenosine monophosphate (AMP) to immune-suppressive adenosine (ADO), was identified highly expressed on ERCs. The present study was conducted to investigate whether the expression of CD73 on ERCs is critical for its therapeutic effects in Con A-induced hepatitis.. ERCs knocking out CD73 were generated with lentivirus-mediated CRISPR-Cas9 technology and identified by flow cytometry, western blot and AMPase activity assay. CD73-mediated immunomodulatory effects of ERCs were investigated by CD4. Expression of CD73 on ERCs could effectively metabolize AMP to ADO, thereby inhibiting the activation and function of conventional CD4. Taken together, it is concluded that CD73 is critical for the therapeutic efficiency of ERCs in the treatment of Con A-induced hepatitis.

Topics: Adenosine Monophosphate; Animals; Concanavalin A; Hepatitis; Mice; Mice, Inbred C57BL; Th1 Cells; Transaminases

Acute hepatitis (AH) is a common liver disease with an increasing number of patients each year, requiring the development of new treatments. Hence, our work aimed to evaluate the therapeutic effect of

Topics: Acute Disease; Animals; Concanavalin A; Hepatitis; Humans; Inflammation; Mice; Mitogen-Activated Protein Kinase 1; Oryza; Protein Kinase C-alpha; Proto-Oncogene Proteins c-mdm2; Signal Transduction; Tumor Suppressor Protein p53

The IL-36 family, including IL-36α, IL-36β, IL-36γ, and IL-36R antagonist, belong to the IL-1 superfamily. It was reported that IL-36 plays a role in immune diseases. However, it remains unclear how IL-36 regulates inflammation. To determine the role of IL-36/IL-36R signaling pathways, we established an acute hepatitis mouse model (C57BL/6) by i.v. injection of the plant lectin Con A. We found that the levels of IL-36 were increased in the liver after Con A injection. Our results demonstrated the infiltrated neutrophils, but not the hepatocytes, were the main source of IL-36 in the liver. Using the IL-36R

Topics: Animals; Biomarkers; Concanavalin A; Cytokines; Disease Models, Animal; Disease Susceptibility; Hepatitis; Immunophenotyping; Interleukin-1; Liver; Mice; Mice, Knockout; Neutrophil Infiltration; Receptors, Interleukin-1; Signal Transduction; T-Lymphocyte Subsets

Cucurbitacins are highly oxygenated tetracyclic triterpenoids, that represent the major metabolites reported from C. colocynthis (L.) Schrad.. Cucurbitacin E glucoside (CuE) is a tetracyclic triterpene glycoside separated from Cucurbitaceae plants. CuE has potent anti-inflammatory, immunomodulatory, and anti-tumor properties.. The current study aimed at examining the hepatoprotective effect of CuE against concanavalin A (Con A)-produced hepatitis.. Mice were intravenously administered Con A (15 mg/kg) to induce AIH. CuE was orally administered at two different doses for five days preceding Con A injection.. Collectively, these results demonstrated the remarkable hepatoprotective potential of CuE towards Con A-induced AIH which was mediated via suppression of oxidative stress, enhancing SIRT1/Nrf2/HO-1, and prohibition of the NF-κB/NLRP3 signaling. CuE could be a candidate for hepatitis patients.

Topics: Animals; Antioxidants; Concanavalin A; Glucosides; Hepatitis; Humans; Mice; NF-E2-Related Factor 2; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Oxidative Stress; RNA, Messenger; Signal Transduction; Sirtuin 1; Triterpenes

Acute liver inflammatory reactions contribute to many health problems; thus, it is critical to understand the underlying pathogenic mechanisms of acute hepatitis. In this study, an experimental in vivo model of concanavalin A (ConA)-induced hepatitis was used.. iNOS. iNOS may contribute to ConA-induced inflammation by promoting the activation of proinflammatory macrophages.

Topics: Animals; Concanavalin A; Hepatitis; Inflammation; Macrophages; Mice; Mice, Inbred C57BL; Nitric Oxide Synthase Type II

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

The cell-cell interaction between hepatocytes and Kupffer cells (KCs) is crucial for maintaining liver homeostasis, and the loss of KCs and hepatocytes is known to represent a common pathogenic phenomenon in autoimmune hepatitis. Until now, the mechanisms of cell-cell interaction between hepatocytes and KCs involved in immune-mediated hepatitis remains unclear. Here we dissected the impact of activated mTORC1 on the cell-cell interaction of KCs and hepatocyte in immune-mediated hepatitis. In the liver from patients with AIH and mice administrated with Con-A, mTORC1 was activated in both KCs and hepatocytes. The activated mTORC1 signal in hepatocytes with Con-A challenge caused a markedly production of miR-329-3p. Upregulated miR-329-3p inhibited SGMS1 expression in KCs through paracrine, resulting in the death of KCs. Most of maintained KCs were p-S6 positive and distributed in hepatocyte mTORC1 negative area. The activation of mTORC1 enabled KCs expressed complement factor B (CFB) to enhance the complement alternative system, which produced more complement factors to aggravate liver injury. Our findings remonstrate a heterogeneous role of mTORC1 in specific cell type for maintaining tolerogenic liver environment, and will form the basis for the development of new interventions against immune-mediated hepatitis.

Topics: Animals; Concanavalin A; Hepatitis; Hepatocytes; Kupffer Cells; Liver; Mechanistic Target of Rapamycin Complex 1; Mice; MicroRNAs

Liver function abnormalities are common in patients with inflammatory arthritis. However, the precise mechanism is still unclear. In this study, inflammatory arthritis was established in mice by subcutaneous injection of complete Freund's adjuvant, and the intravenous injection of concanavalin A (Con A) was employed to induce acute immune-mediated hepatitis in mice. The result showed that the arthritis mice were more susceptible to ConA-induced hepatitis than the control mice, as evidenced by increased hepatic necrosis, elevated serum alanine aminotransferase activity, and raised inflammatory cytokines. Besides, the in vitro assay demonstrated that the T cells from arthritis mice were more sensitive to the Con A stimulation than those from control mice. Moreover, we determined that the level of leptin, a kind of adipokine, was significantly increased in the serum and hepatic T cells of arthritis mice. Interestingly, the data indicated that the enhanced expression of leptin in hepatic T cells is responsible for the hypersensitivity of arthritis mice-derived T cells to Con A challenge. Collectively, our findings demonstrate an unexpected role of leptin in the connection between inflammatory arthritis and acute immune-mediated hepatitis, thus providing new insight into the clinical therapy of arthritis-related liver dysfunction.

Topics: Acute Disease; Animals; Arthritis; Concanavalin A; Cytokines; Disease Susceptibility; Hepatitis; Hypersensitivity; Inflammation; Inflammation Mediators; Leptin; Liver; Lymphocyte Activation; Mice, Inbred C57BL; Signal Transduction; T-Lymphocytes

Aberrant lymphocyte homing could potentially link inflammatory processes in the intestine and the liver, as distinct hepatobiliary diseases frequently develop as extra-intestinal manifestations in inflammatory bowel disease. In this study, we examined the role of the gut-tropic leukocyte adhesion molecule β7 integrin and its endothelial ligand mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) in immune-mediated hepatitis in mice.. Wild-type (WT) mice, MAdCAM-1-deficient mice, β7 integrin-deficient mice, RAG-2-deficient mice, RAG-2/MAdCAM-1 double-deficient mice, and RAG-2/β7 integrin double-deficient mice were subjected to concanavalin A (ConA)-induced hepatitis. The degree of hepatitis was evaluated by histology, flow cytometry, and expression analysis of inflammatory mediators. The motility of lymphocytes in progressive liver damage was assessed by intravital laser scanning multiphoton microscopy.. Ablation of MAdCAM-1 or β7 integrin ameliorated ConA-induced hepatitis in mice. β7 integrin-deficient lymphocytes caused less liver damage than WT lymphocytes in ConA-treated RAG-2-deficient mice. Moreover, WT lymphocytes caused less liver damage in ConA-treated RAG-2/β7 integrin double-deficient mice than in similarly treated RAG-2-deficient mice, indicating that β7 integrin expression contributes significantly to the liver damage mediated by innate immune cells. MAdCAM-1 expression was dependent on β7 integrin expression on adaptive and innate immune cells. Most importantly, lymphocytes in ConA-treated MAdCAM-1-deficient mice displayed more motility and less adhesion in the liver sinusoids in vivo, than lymphocytes in similarly treated WT mice.. These data suggest that β7 integrin expression on lymphocytes and innate immune cells contributes to MAdCAM-1 upregulation and liver damage in acute immune-mediated hepatitis, most likely by facilitating lymphocyte/sinusoidal endothelial cell interactions.

Topics: Animals; Cell Adhesion Molecules; Concanavalin A; DNA-Binding Proteins; Endothelium, Vascular; Hepatitis; Integrins; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Mucoproteins

The IL-33/ST2 axis is known to be involved in liver pathologies and IL-33 is over-expressed in mouse hepatitis models. We aimed to investigate the proposed protective effect of IL-33 in murine fulminant hepatitis induced by a Toll like receptor 3 (TLR3) viral mimetic, Poly I:C or by Concanavalin-A (ConA). The Balb/C mice were administered intravenously with ConA (15 mg/kg) or Poly I:C (30 μg/mouse) to induce acute hepatitis along with vehicle control. The recombinant mouse IL-33 (rIL-33) was injected (0.2 μg/mouse) to mice 2 h prior to ConA or Poly I:C injection to check its hepato-protective effects. The gross lesions, level of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), histopathology (H&E staining) and levels of IFNγ and TNFα were measured by ELISA. The gross pathological liver injury induced by Poly I:C or ConA was reduced by rIL-33 administration in mice. The levels of AST and ALT were significantly (P ≤ 0.05) higher in mice challenged with Poly I:C or ConA in comparison to control mice. The rIL-33 pre-treated mice in both Poly I:C and ConA challenge groups showed significantly (P ≤ 0.05) lower levels of AST and ALT, and decreased liver injury (parenchymal and per-vascular necrotic areas) in histological liver sections. The soluble levels of TNFα and IFNγ were significantly (P ≤ 0.05) raised in Poly I:C or ConA challenged mice than control mice. The levels of TNFα and IFNγ were significantly reduced (P ≤ 0.05) in rIL-33 pre-treated mice. In conclusion, the exogenous IL-33 administration mitigated liver injury and inflammation (decreased levels of IFNγ and TNFα) in Poly I:C and ConA-induced acute hepatitis in mice.

Topics: Animals; Concanavalin A; Hepatitis; Inflammation; Interleukin-33; Liver; Mice; Poly I

Mesenchymal stromal cells and immunosuppressive factor IL-37 can both suppress concanavalin A (Con A)-induced hepatitis in mice. Endometrial regenerative cells (ERCs), novel types of mesenchymal-like stromal cells, possess powerful immunomodulatory effects and are effective in treating various diseases. The aim of this study was to explore the effects of ERCs in suppressing Con A-induced hepatitis and determine whether IL-37 overexpression could enhance the therapeutic effect of ERCs in this process.. ERCs were extracted from the menstrual blood of healthy female volunteer donors. The IL-37 gene was transferred into ERCs, and the expression of IL-37 in cells was detected by western blot and enzyme-linked immunosorbent assay. Hepatitis was induced by Con A in C57BL/6 mice that were randomly divided into groups treated with phosphate-buffered saline, ERCs, IL-37 or ERCs transfected with the IL-37 gene (IL-37-ERCs). Cell tracking, liver function, histopathological and immunohistological changes, immune cell proportions and levels of cytokines were measured 24 h after Con A administration.. Compared with ERC or IL-37 treatment, IL-37-ERCs further reduced levels of liver enzymes (alanine aminotransferase and aspartate aminotransferase) and improved histopathological changes in the liver. In addition, IL-37-ERC treatment further reduced the proportions of M1 macrophages and CD4. The results of this study suggest that ERCs can effectively alleviate Con A-induced hepatitis. Furthermore, IL-37 overexpression can significantly enhance the therapeutic efficacy of ERCs by augmenting the immunomodulatory and anti-inflammatory properties of ERCs. This study may provide a promising strategy for treatment of T-cell-dependent hepatitis.

Topics: Animals; Concanavalin A; Cytokines; Endometrium; Female; Hepatitis; Humans; Liver; Mice; Mice, Inbred C57BL

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Concanavalin A; Disease Models, Animal; Hepatitis; Hepatocytes; Inflammation; Liver; Male; Mice; Mice, Inbred C57BL; Necrosis; Propane; Sulfides

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

A growing body of evidence shows that neuronal activity is involved in modulating the efficacy of acupuncture therapy. However, it has been seldom investigated whether neuronal activity following acupuncture stimulation is effective at regulating hepatic inflammation.. Using the concanavalin A (ConA) model of hepatitis, we investigated the regulation of inflammatory cytokine tumor necrosis factor (TNF)-α in the liver tissue and the blood after acupuncture stimulation at ST36.. Mice were subjected to ConA injection, acupuncture stimulation at ST36 by manual acupuncture (MA) or electroacupuncture (EA) procedures, and vagotomy (VNX). Liver tissue and blood were collected for TNF-α analysis. TNF-α mRNA was analyzed by real-time polymerase chain reaction (PCR), and TNF-α, CD11b, CD68, and Erk1/2 proteins were analyzed by Western blotting, immunofluorescence staining, and enzyme-linked immunosorbent assay.. TNF-α mRNA and protein were induced in CD11b-positive hepatic cells and the plasma at 6-24 h after ConA injection. The application of MA or EA was very effective at attenuating the production of TNF-α. Anti-inflammatory effects of acupuncture were greatly suppressed by VNX in ConA-injected animals, suggesting the requirement of vagus nerve activity in acupuncture-mediated anti-inflammatory responses. Electrical stimulation of the sciatic nerve (SNS) resulted in an anti-inflammatory effect similar to acupuncture stimulation. In parallel with TNF-α, production of phospho-Erk1/2, which was induced in the liver tissue, was downregulated by MA and EA in liver cells.. The regulatory effects of acupuncture stimulation on inflammatory responses in the liver may be modulated through the activation of the vagus nerve pathway.

Topics: Acupuncture Points; Acupuncture Therapy; Animals; Concanavalin A; Hepatitis; Humans; Male; Mice; Mice, Inbred BALB C; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Vagus Nerve

Despite knowledge regarding the effects of antioxidants in ameliorating oxidative damage, evidence concerning their effects on activated immune cells is lacking. Here, a concanavalin A (Con A)-induced hepatitis mouse model was used to investigate the protective effects and immune regulatory mechanisms of mitochondrial-targeted ubiquinone (MitoQ).. NKT cells were critical for extensive pro-inflammatory cytokine production and prolonged liver injury upon Con A challenge, while IFN-γ-producing non-NKT cells played an important role during the hyperacute phase. MitoQ treatment not only ameliorated NKT cell-independent hyperacute hepatitis within 12 h post Con A administration but also alleviated NKT cell-dependent extended liver injury at 24 h. The underlying mechanisms involved an inhibition of the heightened activation of iNKT cells and conventional T cells, suppression of the excessive production of IFN-γ, TNF-α and IL-6, and modulation of aberrant AMPK and mTORC1 pathways.. MitoQ efficiently alleviates Con A-induced hepatitis through immune regulation, suggesting a new therapeutic approach for immune-mediated liver injury by targeting mitochondrial ROS.

Topics: AMP-Activated Protein Kinases; Animals; Antigens, CD1d; Antioxidants; Concanavalin A; Cytokines; Female; Hepatitis; Immunomodulation; Liver; Male; Mechanistic Target of Rapamycin Complex 1; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Natural Killer T-Cells; Organophosphorus Compounds; Reactive Oxygen Species; Ubiquinone

Liver plays a crucial role in innate immunity reactions. This role predisposes the liver to innate-mediated liver injury when uncontrolled inflammation occurs. In this study, the effect of febuxostat administration on acute liver injury induced by concanavalin A (Con A) injection into mouse eye orbital sinus was studied.. Two doses of febuxostat (10 and 20 mg/kg, orally) were administered either 1 h before or 30 min after the administration of Con A. Febuxostat at a low dose (10 mg/kg) before and after Con A modulated the elevation of serum ALT, liver uric acid, liver myeloperoxidase (MPO), and interleukin-1β (IL-1β) induced by Con A. The same dose of febuxostat before Con A also decreased serum total bilirubin and neutrophil infiltration, as evidenced by flow cytometry and histopathological analysis.. Febuxostat at a high dose (20 mg/kg) significantly improved serum ALT, AST, albumin, total bilirubin, liver uric acid, MPO, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), IL-1β, and neutrophil infiltration induced by Con A administration. The results of histopathological examination of liver cells paralleled the observed biochemical improvements. Hepatocyte apoptosis as evidenced by immunohistochemical examination of cleaved caspase-3 was markedly decreased in the febuxostat protection and treatment groups, in a dose-dependent manner SIGNIFICANCE: These results indicate that febuxostat, especially at the higher dose, may be an effective inhibitor of immune reactions evoked by Con A administration.

Topics: Animals; Apoptosis; Caspase 3; Chemokine CCL2; Concanavalin A; Febuxostat; Hepatitis; Interleukin-1beta; Liver; Male; Mice; Neutrophil Infiltration; Neutrophils; Peroxidase; Tumor Necrosis Factor-alpha; Uric Acid

Ambroxol hydrochloride is being used in respiratory diseases as a broncholytic therapy. Beta-Glucosylceramide (GC) is a naturally occurring glycosphingolipid that exerts an immune protective effect. The aim of the present study was to determine the synergistic immunomodulatory effect between these two compounds.. Immune-mediated hepatitis was induced in the mice by administration of Con A. Mice were treated with either Ambroxol or GC alone or with the combination of both. Mice were followed for their effect on the liver injury, cytokine profile, and the immune system.. Coadministration of Ambroxol and GC significantly alleviated the liver injury induced by ConA, as demonstrated by the decreased liver enzymes. The combined treatment had a statistically significant synergistic effect on the suppression of intrahepatic CD8+CD25+, an increase in the CD4/CD8 lymphocyte ratio and in the CD8+ intrahepatic lymphocyte trapping, as well as on change of serum in the IL4 levels. The beneficial effect was associated with the promotion of regulatory T lymphocytes subsets, and with a trend for a pro-inflammatory to an anti-inflammatory cytokine shift.. Coadministration of Ambroxol with GC exerted a synergistic immunoprotective effect in a model of immune-mediated acute liver damage. Considering the high safety profile of both agents, the combination may become a novel immunomodulatory non-immunosuppressive therapeutic agent.. Coadministration of Ambroxol with glucocerebroside exerted a synergistic immunoprotective effect in a model of immune-mediated acute liver damage.

Topics: Ambroxol; Animals; Anti-Inflammatory Agents; Concanavalin A; Cytokines; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Glucosylceramides; Hepatitis; Immunologic Factors; Inflammation Mediators; Liver; Male; Mice, Inbred C57BL; T-Lymphocytes

Increasing number of studies provide evidence that the vagus nerve stimulation (VNS) dampens inflammation in peripheral visceral organs. However, the effects of afferent fibers of the vagus nerve (AFVN) on anti-inflammation have not been clearly defined. Here, we investigate whether AFVN are involved in VNS-mediated regulation of hepatic production of proinflammatory cytokines.. An animal model of hepatitis was generated by intraperitoneal (i.p.) injection of concanavalin A (ConA) into rats, and electrical stimulation was given to the hepatic branch of the vagus nerve. AFVN activity was regulated by administration of capsaicin (CAP) or AP-5/CNQX and the vagotomy at the hepatic branch of the vagus nerve (hVNX). mRNA and protein expression in target tissues was analyzed by RT-PCR, real-time PCR, western blotting and immunofluorescence staining. Hepatic immune cells were analyzed by flow cytometry.. Our data indicate that the activity of AFVN contributes to hepatic anti-inflammatory responses mediated by hVNS in ConA model of hepatitis in rats.

Topics: alpha7 Nicotinic Acetylcholine Receptor; Animals; Biomarkers; Chemotaxis, Leukocyte; Concanavalin A; Cytokines; Disease Models, Animal; Disease Susceptibility; Gene Expression; Hepatitis; Immunohistochemistry; Inflammation Mediators; Male; Neurons; Rats; STAT3 Transcription Factor; Vagotomy; Vagus Nerve; Vagus Nerve Stimulation

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

The BTLA-HVEM checkpoint axis plays extensive roles in immunomodulation and diseases, including cancer and autoimmune disorders. However, the functions of this checkpoint axis in hepatitis remain limited. In this study, we explored the regulatory role of the Btla-Hvem axis in a ConA-induced hepatitis model in zebrafish. Results showed that Btla and Hvem were differentially expressed on intrahepatic Cd8

Topics: Animals; CD8-Positive T-Lymphocytes; Concanavalin A; Disease Models, Animal; Drosophila Proteins; HEK293 Cells; Hepatitis; Homeostasis; Humans; Inflammation; Liver; Receptors, Immunologic; Receptors, Tumor Necrosis Factor, Member 14; Vesicular Transport Proteins; Zebrafish

Aldehyde dehydrogenase 2 (ALDH2), a key enzyme to detoxify acetaldehyde in the liver, exists in both active and inactive forms in humans. Individuals with inactive ALDH2 accumulate acetaldehyde after alcohol consumption. However, how acetaldehyde affects T-cell hepatitis remains unknown.. Wild-type (WT) and. Ethanol feeding exacerbated ConA-induced hepatitis in WT mice but surprisingly attenuated it in. ALDH2 deficiency is associated with elevated acetaldehyde and glucocorticoids post-alcohol consumption, thereby inhibiting T-cell activation and hepatitis.

Topics: Aldehyde Dehydrogenase, Mitochondrial; Animals; Binge Drinking; Concanavalin A; Corticosterone; Disease Models, Animal; Ethanol; Glucose; Hepatitis; Humans; Hydrocortisone; Mice; T-Lymphocytes

A series of novel fluorine-containing lupane triterpenoid acid derivatives with fluoroaromatic amide moieties at the C-28 position (1-8) or with 2-(fluoroacyl)cyclopentane-1,3-dione fragments at the C-3 position (9-18) of lupane skeleton was synthesized. A simple synthesis of novel lupane triterpenoid hybrids with 2-(fluoroacyl)-2-cyclopenten-1-one moieties was developed. An interaction of 2-acyl-3-chlorocyclopent-2-en-1-ones, obtained from corresponding cyclic β-triketones, with methyl 3-amino-3-deoxybetulinate gave 3β-isomers (9-13) and 3α-isomers (14-18) of target hybrids, which were isolated as individual compounds. Anti-inflammatory properties of selected synthesized compounds were studied in vivo using the histamine-, concanavalin A- and sheep erythrocytes immunization-induced mouse paw edema models. The antioxidant activity was investigated in vivo on the model of tetracycline-induced hepatitis. Majority of synthesized fluorine-containing lupane triterpenoid acid derivatives exhibited significant anti-inflammatory and antioxidant effects. Among studied compounds, 3β-hybrid 11 with 2-perfluorobutanoyl-2-cyclopenten-1-one moiety was the most potent bioactive compound.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Betulinic Acid; Concanavalin A; Disease Models, Animal; Drug Design; Edema; Female; Fluorine; Hepatitis; Histamine; Male; Mice; Mice, Inbred C57BL; Molecular Conformation; Pentacyclic Triterpenes; Tetracycline; Triterpenes

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

Topics: Acute Disease; Animals; Concanavalin A; Cytokines; Gene Expression Regulation; Hepatitis; Inflammation; Inflammation Mediators; Kupffer Cells; Leukocytes, Mononuclear; Liver; Mice, Inbred C57BL; Mice, Knockout; NADPH Oxidases; Phagocytosis; Reactive Oxygen Species; Receptors, Calcitriol; RNA, Messenger

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

A series of (1,2,4)triazole[4,3-a]pyridine (TZP) derivatives have been designed and synthesized. Compound 8d was identified as having the most potent inhibitory activity on NO release in response to lipopolysaccharide (LPS) stimulation and inhibition of the migration induced by MCP-1 protein on RAW264.7 macrophages. Based on the screening data, an immunofluorescence assay and a real-time qPCR assay were conducted, indicating that compound 8d suppressed NF-κB p65 translocation and expression of inflammatory genes by concanavalin A (Con A)-induced RAW264.7 macrophages. More importantly, 8d also exhibited potent efficacy, alleviating Con A-induced hepatitis by downregulating the levels of plasma alanine transaminase (ALT), aspartate transaminase (AST) and inflammatory infiltration in a mouse autoimmune hepatitis (AIH) model. In addition, the flow cytometry (FCM) data showed that compound 8d inhibited the accumulation of MDSCs in the liver of Con A-induced mice. These findings raise the possibility that compound 8d might serve as a potential agent for the treatment of AIH.

Topics: Animals; Cell Survival; Cells, Cultured; Concanavalin A; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Design; Female; Hepatitis; Humans; Lipopolysaccharides; Mice; Mice, Inbred BALB C; Molecular Structure; Nitric Oxide; Pyridines; RAW 264.7 Cells; Structure-Activity Relationship; Triazoles

The effects of mesenchymal stem cells (MSCs) on the phenotype and function of natural killer T (NKT) cells is not understood. We used concanavalin A (Con A) and α-galactosylceramide (α-GalCer)-induced liver injury to evaluate the effects of MSCs on NKT-dependent hepatotoxicity. Mouse MSCs (mMSCs) significantly reduced Con A- and α-GalCer-mediated hepatitis in C57Bl/6 mice, as demonstrated by histopathological and biochemical analysis, attenuated the influx of inflammatory [T-bet

Topics: Animals; Apoptosis; Cell Count; Concanavalin A; Cytokines; Galactosylceramides; Gene Expression Regulation; Hepatitis; Humans; Indoleamine-Pyrrole 2,3,-Dioxygenase; Injections; Leukocytes, Mononuclear; Liver; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice, Inbred C57BL; Natural Killer T-Cells; Nitric Oxide Synthase Type II; Paracrine Communication

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

Although detailed pathophysiological mechanisms of fulminant hepatitis remain elusive, immune cell recruitment with excessive cytokine production is a well-recognized hallmark of the disease. We determined the function of orphan nuclear receptor small heterodimer partner (SHP) in concanavalin A (ConA)-induced hepatitis model. Male C57BL/6 J mice were injected intravenously with either a lethal dose (25 mg/kg) or a sub-lethal dose (15 mg/kg) of ConA. For the C-X-C motif chemokine ligand (CXCL) 2 neutralization study, mice were intravenously administered anti-mouse CXCL2 antibody (100 μg/mouse). Thirty-six hours following lethal dose of ConA administration, 47% wild type (WT) mice were alive, whereas >85% of Shp knockout (KO) were dead. Shp KO mice were highly susceptible to ConA-induced liver injury and exhibited increased liver necrosis upon sub-lethal dose of ConA administration. FACS analysis and immunohistochemical staining showed significantly higher neutrophil infiltration in Shp KO mice, as compared with WT mice. We found that also in the WT situation, Shp expression gradually decreased, while Cxcl2 expression increased until 6 h, and vice versa at 24 h upon ConA-treatment, indicating an inverse correlation between Shp and Cxcl2 expression during ConA-induced hepatitis. Furthermore, in vivo neutralization of CXCL2 with neutralizing antibody reduces ConA-induced plasma ALT and AST levels, hepatocyte death and neutrophil infiltration in Shp KO mice. Collectively, these results confirm that lacking of SHP results in CXCL2-dependent neutrophil infiltration in ConA-induced liver damage. SHP plays a protective, anti-inflammatory role in liver during acute liver inflammation.

Topics: Animals; Chemokine CXCL2; Concanavalin A; Disease Models, Animal; Hepatitis; Liver; Liver Function Tests; Male; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Receptors, Cytoplasmic and Nuclear

As a phenylpropanoid and dibenzylbutyrolactone lignan present in medical plants, such as those used in traditional Chinese herbal medicine, including Arctium lappa (Niubang), arctigenin exhibits antimicrobial, anti-inflammatory, and anticancer activities. In this study, we investigated the protective role of arctigenin in Concanavalin A (ConA)-induced acute hepatitis in mice. Arctigenin remarkably reduced the congestion and necroinflammation of livers, and improved hepatic function (ALT and AST) in ConA-induced acute hepatitis in vivo. The infiltration of CD4 T, NKT and macrophages into the livers was found to be reduced with arctigenin treatment. Arctigenin suppressed ConA-induced T lymphocyte proliferations that might have resulted from enhanced IL-10 production by macrophages and CD4 T cells. These results suggested that arctigenin could be a powerful drug candidate for acute hepatitis through immune suppression.

Topics: Acute Disease; Animals; CD4-Positive T-Lymphocytes; Concanavalin A; Furans; Hepatitis; Inflammation; Inflammation Mediators; Interleukin-10; Lignans; Liver; Macrophages; Male; Mice; Mice, Inbred BALB C; Natural Killer T-Cells; Protective Agents; RAW 264.7 Cells

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

Concanavalin A-induced autoimmune hepatitis is a well-established experimental model for immune-mediated liver injury. It has been widely used in the therapeutic studies of immune hepatitis. The in-depth analysis of dysregulated proteins from comparative proteomic results indicated that the activation of immune system resulted in the deregulation of autophagy. Follow-up studies validated that some immune related proteins, including Stat1, Pkr, Atg7, and Adrm1, were indeed upregulated. The accumulations of LC3B-II and p62 were confirmed by immunohistochemistry and Western blot analyses. Arctigenin pretreatment significantly alleviated the liver injury, as evidenced by biochemical and histopathological investigations, whose protective effects were comparable with Prednisone acetate and Cyclosporin A. Arctigenin pretreatment decreased the levels of IL-6 and IFN-γ, but increased the ones of IL-10. Next, the quantitative proteomic analysis demonstrated that ARC pretreatment suppressed the activation of immune system through the inhibition of IFN-γ signaling, when it downregulated the protein expressions of Stat1, P-Stat1, Pkr, P-Pkr, Bnip3, Beclin1, Atg7, LC3B, Adrm1, and p62. Meanwhile, Arctigenin pretreatment also reduced the gene expressions of Stat1, Pkr, and Atg7. These results suggested that Arctigenin alleviated autophagy as well as apoptosis through inhibiting IFN-γ/IL-6/Stat1 pathway and IL-6/Bnip3 pathway. In summary, the comparative proteomic analysis revealed that the activation of immune system led to Concanavalin A-induced hepatitis. Both autophagy and apoptosis had important clinical implications for the treatment of immune hepatitis. Arctigenin might exert great therapeutic potential in immune-mediated liver injury.

Topics: Animals; Apoptosis; Autophagy; Biomarkers; Concanavalin A; Cytokines; Disease Models, Animal; Female; Furans; Hepatitis; Immune System; Immunohistochemistry; Inflammation Mediators; Lignans; Mice; Proteomics

Concanavalin A is known to activate T cells and to cause liver injury and hepatitis, mediated in part by secretion of TNFα from macrophages. Poly(ADP-ribose) polymerase-1 (PARP-1) inhibitors have been shown to prevent tissue damage in various animal models of inflammation. The objectives of this study were to evaluate the efficacy and mechanism of the PARP-1 inhibitor 3-aminobenzamide (3-AB) in preventing concanavalin A-induced liver damage.. We tested the in vivo effects of 3-AB on concanavalin A-treated mice, its effects on lipopolysaccharide (LPS)-stimulated macrophages in culture, and its ability to act as a scavenger in in vitro assays.. 3-AB markedly reduced inflammation, oxidative stress, and liver tissue damage in concanavalin A-treated mice. In LPS-stimulated RAW264.7 macrophages, 3-AB inhibited NFκB transcriptional activity and subsequent expression of TNFα and iNOS and blocked NO production. In vitro, 3-AB acted as a hydrogen peroxide scavenger. The ROS scavenger N-acetylcysteine (NAC) and the ROS formation inhibitor diphenyleneiodonium (DPI) also inhibited TNFα expression in stimulated macrophages, but unlike 3-AB, NAC and DPI were unable to abolish NFκB activity. PARP-1 knockout failed to affect NFκB and TNFα suppression by 3-AB in stimulated macrophages.. Our results suggest that 3-AB has a therapeutic effect on concanavalin A-induced liver injury by inhibiting expression of the key pro-inflammatory cytokine TNFα, via PARP-1-independent NFκB suppression and via an NFκB-independent anti-oxidative mechanism.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Antioxidants; Benzamides; Cells, Cultured; Concanavalin A; Disease Models, Animal; Hepatitis; Macrophages; Mice; Mitogens; NF-kappa B; Nitric Oxide Synthase Type II; Poly(ADP-ribose) Polymerase Inhibitors; Treatment Outcome; Tumor Necrosis Factor-alpha

Hepatocellular injury is the pathological hallmark of hepatitis and a crucial driver for the progression of liver diseases, while the treatment options are commonly restricted. Interleukin-22 (IL-22) has attracted special attention as a potent survival factor for hepatocytes that both prevents and repairs the injury of hepatocytes through activation of STAT3 signaling pathway. We hypothesized that the ability to generate potent expression of IL-22 locally for the treatment of severe hepatocellular injury in hepatitis was a promising strategy to enhance efficacy and overcome off-target effects. Accordingly, we developed a polypeptide penetratin-based hybrid nanoparticle system (PDPIA) carrying IL-22 gene by a self-assembly process. This nanocomplex modified with penetratin featured direct translocation across the cellular or endosomal membrane but mild zeta-potential to facilitate the high cellular internalization and endosomal escape of the gene cargos as well as scarcely Kupffer cells uptake. More importantly, PDPIA afforded preferential liver accumulation and predominant hepatocytes internalization following systemic administration, which showed pharmacologically suitable organ and sub-organ-selective properties. Subsequent studies confirmed a considerable protective role of PDPIA in a model of severe hepatitis induced by concanavalin A, evidenced by reduced hepatocellular injury and evaded immune response. The locally expressed IL-22 by PDPIA activated STAT3/Erk signal transduction, and thus promoted hepatocyte regeneration, inhibited reactive oxygen species (ROS) accumulation as well as prevented the dysfunction of mitochondrial. In addition, this system did not manifest side effects or systemic toxicity in mice. Collectively, the high versatility of PDPIA rendered its promising applications might be an effective agent to treat various hepatic disorders.

Topics: Animals; Cell Line; Cell Survival; Cell-Penetrating Peptides; Concanavalin A; Dendrimers; Drug Carriers; Genetic Therapy; Hepatitis; Hepatocytes; Humans; Interleukin-22; Interleukins; Kupffer Cells; Liver; Male; Membrane Potential, Mitochondrial; Mice, Inbred BALB C; Nanoparticles; Polyethylene Glycols; Reactive Oxygen Species

Recently, we reported that orphan nuclear receptor small heterodimer partner (SHP) is involved in neutrophil recruitment through the regulation of C-X-C motif chemokine ligand 2 (CXCL2) expression in a concanavalin A (ConA)-induced hepatitis model. In the present study, we examined the mechanisms underlying CXCL2 regulation by SHP and the cell types involved in liver inflammation. To this end, either Shp knockout (KO) or wild-type (WT) bone marrow cells were transferred into sublethally-irradiated WT (KO → WT or WT → WT) or Shp KO (KO → KO or WT → KO) recipients, followed by intravenous injection of ConA (20-30 mg/kg) 8 weeks later. The KO recipient groups showed higher ConA-induced lethality than the WT recipient groups. Accordingly, plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and inflammatory cytokine expressions were significantly higher in the KO recipients than in the WT recipients regardless of donor genotype. Massively increased hepatocyte death in KO recipients, as determined by H&E and TUNEL staining, was observed after ConA challenge. Bone marrow chimera experiments and in vitro chemotaxis assay also showed that SHP-deficient hepatocytes have an enhanced ability to recruit neutrophils to the injured liver. In vitro promoter assays showed that SHP is a negative regulator of Cxcl2 transcription by interfering with c-Jun binding to the AP-1 site within the Cxcl2 promoter. Collectively, SHP regulates Cxcl2 transcription in hepatocytes, playing a pivotal role in the recruitment of neutrophils. SHP-targeting strategies may represent alternative approaches to control fulminant hepatitis.

Topics: Animals; Chemokine CXCL2; Concanavalin A; Disease Models, Animal; Hepatitis; Hepatocytes; Humans; Inflammation; Liver; Mice; Mice, Knockout; Neutrophil Infiltration; Promoter Regions, Genetic; Receptors, Cytoplasmic and Nuclear; Transcription Factor AP-1

The significance of the relationship between the nervous and immune systems with respect to disease course is increasingly apparent. Immune cells in the liver and spleen are responsible for the development of acute liver injury, yet the regulatory mechanisms of the interactions remain elusive. Calcitonin gene-related peptide (CGRP), which is released from the sensory nervous system, regulates innate immune activation via receptor activity-modifying protein 1 (RAMP1), a subunit of the CGRP receptor. Here, we show that RAMP1 in Kupffer cells (KCs) plays a critical role in the etiology of immune-mediated hepatitis. RAMP1-deficient mice with concanavalin A (ConA)-mediated hepatitis, characterized by severe liver injury accompanied by infiltration of immune cells and increased secretion of pro-inflammatory cytokines by KCs and splenic T cells, showed poor survival. Removing KCs ameliorated liver damage, while depleting T cells or splenectomy led to partial amelioration. Adoptive transfer of splenic T cells from RAMP1-deficient mice led to a modest increase in liver injury. Co-culture of KCs with splenic T cells led to increased cytokine expression by both cells in a RAMP1-dependent manner. Thus, immune-mediated hepatitis develops via crosstalk between immune cells. RAMP1 in KCs is a key regulator of immune responses.

Topics: Animals; Calcitonin Gene-Related Peptide; Cells, Cultured; Concanavalin A; Cytokines; Gene Deletion; Hepatitis; Immunity, Innate; Kupffer Cells; Liver; Male; Mice, Inbred C57BL; Mice, Knockout; Receptor Activity-Modifying Protein 1; T-Lymphocytes

Topics: Animals; Anti-Inflammatory Agents; Concanavalin A; Female; Hepatitis; Lepidium; Medicine, Traditional; Mice; Mice, Inbred BALB C; NF-kappa B; Plant Extracts; Sperm Motility

Con A-induced hepatitis in mice is an established model of autoimmune hepatitis (AIH). JKB-122, a toll-like receptor 4 (TLR4) antagonist, was tested for hepatotprotectant activity. Within several hours of Con A challenge (15mg/kg iv), increased production of proinflammatory cytokines with inflammatory infiltrate occurred in the liver. The severity of tissue necrosis and the amount of circulating liver enzymes peak at 24h post Con A challenge. JKB-122 was given 24 and 16h before, then concurrently, and 4 and 8h (× 5 doses) after challenge with Con A. Serum and liver were harvested at 3, 9 and 24h post Con A challenge. JKB-122 at 20 and 50mg/kg po prevented the increase of serum liver enzymes by 47% and 95% respectively vs vehicle control 24h post Con A. JKB-122 significantly inhibited Con A-induced pathological lesions in the liver and the amount of IFN-γ IL-1β, IL-4, IL-5, IL-6, IL-17A and TNF-α starting as early as 3h post Con A. Moreover, JKB-122 given concurrently (× 3 doses) with Con A showed similar effect. Finally, JKB-122 enhanced the therapeutic effects of submaximal dose of prednisolone with improved lesion score. It is concluded that JKB-122 at 20 and 50mg/kg po caused dose-dependent inhibition of elevated liver enzymes in Con A-induced hepatitis in mice, indicating hepatoprotectant activity. The results suggest that JKB-122 as monotherapy or in combination with prednisolone may offer a viable approach to the treatment of AIH.

Topics: Animals; Concanavalin A; Cytokines; Cytoprotection; Dose-Response Relationship, Drug; Drug Interactions; Hepatitis; Liver; Male; Mice; Mice, Inbred BALB C; Organic Chemicals; Prednisolone; Toll-Like Receptor 4

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

Viral hepatitis-induced oxidative stress accompanied by increased levels of transforming growth factor-β (TGF-β) and hepatic fibrosis are hallmarks of hepatitis C virus infection. The present study was designed to investigate the potential protective effect of propolis against liver injury induced by concanavalin A (Con A), a T-cell-dependent model that causes an immune-mediated hepatitis in a similar pattern to the one induced by viral infections. In the present study, rats were randomly divided into four groups. The first group (control) was administered the vehicle of Con A (i.v.) for 24 h. The second group received Con A (12 mg/kg body weight i.v.) for 24 h. The third group received propolis (300 mg/kg by oral gavage) 5 days before and concurrently with Con A for 24 h. The last group received propolis alone. Following a single injection of Con A, histopathological changes as well as significant reduction in albumin level were observed. In addition, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin were significantly increased. These increases correlated with an increase in lipid peroxidation and downregulation of reduced glutathione (GSH) as well as superoxide dismutase (SOD) and catalase activities in liver tissue. Furthermore, these changes were associated with an increase in serum levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) as well as the profibrotic cytokine TGF-β. Moreover, TGF- β activation was accompanied with an increase in Smad phosphorylation. Interestingly, concomitant administration of propolis along with Con A significantly attenuated all these negative effects and improved liver function indicating that propolis has the ability to protect rats from Con A-induced hepatitis.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Bilirubin; Catalase; Concanavalin A; Cytokines; Glutathione; Hepatitis; Lipid Peroxidation; Liver; Male; Propolis; Protective Agents; Rats, Wistar; Reactive Oxygen Species; Serum Albumin; Superoxide Dismutase

Vardenafil is a selective phosphodiesterase-5 inhibitor used for erectile dysfunction treatment. The hepatoprotective role of vardenafil against acute hepatitis is not reported yet. Hence, this study aims to explore the protective role of vardenafil against concanavalin A (Con A) induced acute liver injury. Mice were pretreated with vardenafil (0.17 mg/kg/day) for seven consecutive days, and then subjected to a single IV injection of Con A. The results demonstrated that the vardenafil pretreatment significantly reduced the elevated serum levels of transaminases and alkaline phosphatase. Histopathological examination showed marked necrosis and inflammation in Con A-treated mice which was significantly ameliorated in vardenafil pretreated animals. Vardenafil pretreatment significantly alleviated the expression of nuclear factor kappa-B and inducible nitric oxide synthase in the hepatic tissue. Additionally, serum levels of nitric oxide and tumor necrosis factor-alpha were decreased in vardenafil pretreated animals compared to the Con A group. Therefore, our results demonstrate that vardenafil has hepatoprotective effect and this could be linked to decrease inflammatory mediators.

Topics: Alkaline Phosphatase; Animals; Concanavalin A; Disease Models, Animal; Erectile Dysfunction; Hepatitis; Inflammation; Liver; Male; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Transaminases; Tumor Necrosis Factor-alpha; Vardenafil Dihydrochloride

The dietary flavonoid quercetin has hepatoprotective effects. We analyzed the effects of quercetin on concanavalin A (ConA)-induced hepatitis in mice and its underlying molecular mechanisms of action. Mice were administered quercetin (50 mg/kg body weight, i.p.) or vehicle 30 min before intravenous administration of ConA. Quercetin pretreatment significantly reduced the ConA-induced elevations in plasma aminotransferase concentrations and liver necrosis, as well as reducing serum concentrations of the pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interferon-γ, and interleukin-4. Quercetin pretreatment also reduced expression of high-mobility group box 1 protein (HMGB1) and toll-like receptor (TLR)-2 and TLR-4 messenger RNA (mRNA) and protein in liver tissues. Quercetin pretreatment significantly inhibited degradation of inhibitory kappa B alpha and modulated ConA-induced nuclear translocation in the liver of nuclear factor kappa B (NF-κB) p65. These results demonstrate that quercetin protects against ConA-mediated hepatitis in mice by attenuating the HMGB1-TLRs-NF-κB signaling pathway.

Topics: Active Transport, Cell Nucleus; Animals; Concanavalin A; Down-Regulation; Hepatitis; HMGB1 Protein; Interferon-gamma; Interleukin-4; Liver; Male; Mice; Mice, Inbred BALB C; NF-KappaB Inhibitor alpha; Quercetin; Random Allocation; RNA, Messenger; Toll-Like Receptor 2; Toll-Like Receptor 4; Transaminases; Transcription Factor RelA; Tumor Necrosis Factor-alpha

Resolvins, an endogenous lipid mediator derived from eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) of fish oil, has been reported to have anti-inflammatory and antitumor effect in various pathogenic processes. However, there are no studies about the effects of resolvin D1 and E1 on concanavalin A-induced hepatitis. Hence, the present study is to illustrate whether resolvin D1 and E1 inhibit concanavalin A-induced liver injury, liver cancer and underlying mechanisms by which they may recover. C57BL/6 mice were pretreated with resolvin D1 and E1 for 4 h, and then injected with concanavalin A for 12 h. Subsequently, blood and liver tissue were collected at 0, 2, 4, 8 and 12 h for different analysis. Analysis of inflammatory cytokines indicated that the inhibition of necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, IL-1β and IL-6 could be performed by resolvin D1 and E1. Moreover, Toll-like receptor (TLR) 4 expression, NF-κB and AP-1 activity also have been confirmed to have key roles in the development of liver injury. They were significantly suppressed in the treatment group, compared to model. In addition, resolvin D1 and E1 markedly downregulated CD4+ and CD8+ cell infiltration in the liver. A long-term concanavalin A treatment for 32 weeks was performed to analyze the changes of hepatitis to liver cancer and the antitumor effect of resolving D1 and E1. These results indicated that resolvin D1 and E1 prevent concanavalin A-induced liver injury and the changes of hepatitis to liver cancer in mice through inhibition of inflammatory cytokine secretion and NF-κB/AP-1 activity. Thus, they could be novel target to be considered in the process of finding sufficient drug to protect against various forms of hepatitis and liver cancer.

Topics: Animals; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Concanavalin A; Cytokines; Docosahexaenoic Acids; Eicosapentaenoic Acid; Gene Expression Regulation, Neoplastic; Hepatitis; Liver Neoplasms, Experimental; Male; Mice

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

In this study, we confirmed a protective effect of 15d-PGJ2 in concanavalin A (ConA)-induced fulminant hepatitis in mice and investigated the potential mechanism.. Balb/C mice were injected with ConA (25mg/kg) to induce acute fulminant hepatitis, and 15d-PGJ2 (2.5-10μg) was administered 30min after the ConA injection. The histological grade, pro-inflammatory cytokine and ROS levels, apoptosis and autophagy activity, the expression of HO-1, Nrf2, JNK and Bcl-2 activity were determined 2, 4, and 8h after the ConA injection.. Following ConA challenge, the expression of cytokines tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) was up-regulated. Treatment with 15d-PGJ2 reduced the pathological effects of ConA-induced fulminant hepatitis and significantly reduced the levels of TNF-α, IL-1β and ROS after injection. 15d-PGJ2 inhibited apoptosis and autophagic cell death, facilitated Nrf2 nuclear translocation, increased HO-1 expression and suppressed the JNK activation.. 15d-PGJ2 alleviates ConA-induced acute liver injury in mice by up-regulating the anti-oxidative stress factor HO-1 and reducing the production of cytokines and ROS, thereby inhibiting hepatic cell autophagy probably induced by ROS.

Topics: Acute Disease; Animals; Autophagy; Cell Nucleus; Concanavalin A; Disease Models, Animal; Enzyme Activation; Heme Oxygenase-1; Hepatitis; Hepatocytes; Interleukin-1beta; JNK Mitogen-Activated Protein Kinases; Liver; Male; Mice, Inbred BALB C; NF-E2-Related Factor 2; Phagosomes; Prostaglandin D2; Reactive Oxygen Species; Tumor Necrosis Factor-alpha; Up-Regulation

To assess alterations in perfusion and liver function in the concanavalin A (ConA)-induced mouse model of acute liver failure (ALF) using two magnetic resonance imaging (MRI)-based methods: dynamic contrast-enhanced MRI (DCE-MRI) with Gd-EOB-DTPA contrast agent and arterial spin labelling (ASL).. BALB/c mice were studied using a 9.4 T MRI system. The IntraGateFLASH. The average perfusion values for the liver of the control and ConA group were equal to 245 ± 20 and 200 ± 32 ml/min/100 g (p = 0.008, respectively). DCE-MRI showed that the time to the peak of the image enhancement was 6.14 ± 1.07 min and 9.72 ± 1.69 min in the control and ConA group (p < 0.001, respectively), while the rate of the contrast wash-out in the control and ConA group was 0.037 ± 0.008 and 0.021 ± 0.008 min. Both the ASL and DCE-MRI techniques represent a reliable methodology to assess alterations in liver perfusion and hepatocyte integrity in murine hepatitis.

Topics: Acute Disease; Animals; Concanavalin A; Contrast Media; Gadolinium DTPA; Hepatitis; Hepatocytes; Humans; Liver; Liver Failure, Acute; Magnetic Resonance Imaging; Mice; Mice, Inbred BALB C; Perfusion; Retrospective Studies; Spin Labels

Parthenolide, the principal sesquiterpene lactone present in medicinal plants such as feverfew, has anti-microbial, anti-inflammatory and anticancer activities. In the present study, we investigated the protective role of parthenolide against acute hepatitis in mice. Mice acute hepatitis were induced by Concanavalin A and treated by parthenolide in vivo. Results shown that parthenolide remarkably reduced the congestion and necroinflammation of the mice livers with Concanavalin A-induced acute hepatitis. Meanwhile, parthenolide treatment recover the liver function which indicated by decreased the serum alanine transaminase and alkaline phosphatase activities and promoted the expression of Ki67 in the livers of these mice. In addition, parthenolide administration suppressed the Concanavalin A-induced immune reaction, as indicated by the number of F4/80, CD49b and CD4 cells present in the liver. Furthermore, parthenolide also significantly reduced the expression of pro-inflammatory cytokines such as IFN-γ, TNF-α, IL-17A, IL-1β and IL-6 in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro. Moreover, parthenolide exposure decreased the phosphorylation of STAT3 and p38, and promoted the phosphorylation of p53 in RAW264.7 cells in vitro. In conclusion, parthenolide represents a drug candidate to protect the liver against Concanavalin A-induced acute hepatitis. The possible molecular mechanism involves the anti-inflammatory effects of parthenolide may by suppressing the STAT3/p38 signals and enhanced the p53 signals.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Concanavalin A; Cytokines; Disease Models, Animal; Hepatitis; Humans; Immunity, Cellular; Inflammation Mediators; Liver; Macrophages; Male; Mice; p38 Mitogen-Activated Protein Kinases; RAW 264.7 Cells; Sesquiterpenes; Signal Transduction; STAT3 Transcription Factor; Tumor Suppressor Protein p53

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

Dracocephalum heterophyllum (DH) is a Chinese herbal medicine used in treating hepatitis. However, the protective effects and pharmacological mechanisms of DH in hepatitis are unknown. In this study, we found that pretreatment with DH extract significantly ameliorated liver injury and suppressed the production of inflammatory cytokines, including tumor necrosis factor (TNF-α) and interferon-γ (IFN-γ) in Concanavalin A- (ConA-) induced hepatitis (CIH). DH recruited more CD11b(+) Gr1(+) myeloid-derived suppressor cells (MDSCs) to the liver and suppressed infiltration of macrophages (Kupffer cells) in the liver. The present work explores DH as an effective hepatoprotective medicine to inhibit inflammation and liver injury caused by hepatitis.

Topics: Acute Disease; Animals; Concanavalin A; Female; Flow Cytometry; Hepatitis; In Situ Nick-End Labeling; Interferon-gamma; Lamiaceae; Liver; Mice; Mice, Inbred BALB C; Plant Extracts; Tumor Necrosis Factor-alpha

Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPβ and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ-related signaling intermediates C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPβ and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation.

Topics: Animals; Concanavalin A; Disease Models, Animal; Hepatitis; Humans; Inflammation; Lectins, C-Type; Leukocytes, Mononuclear; Male; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Nitrites; Signal Transduction

Cell death of hepatocytes is a prominent characteristic in the pathogenesis of liver disease, while hepatolysis is a starting point of inflammation in hepatitis and loss of hepatic function. However, the precise molecular mechanisms of hepatocyte cell death, the role of the cytokines of hepatic microenvironment and the involvement of intracellular kinases, remain unclear. Tumor necrosis factor alpha (TNF-α) is a key cytokine involved in cell death or survival pathways and the role of RIPK1 has been associated to the TNF-α-dependent signaling pathway. We took advantage of two different deficient mouse lines, the RIPK1 kinase dead knock-in mice (Ripk1

Topics: Animals; Apoptosis; Cells, Cultured; Concanavalin A; Hepatitis; Hepatocytes; Homeostasis; Inflammation; Liver; Mice, Inbred C57BL; Models, Biological; Protective Agents; Receptor-Interacting Protein Serine-Threonine Kinases; TNF Receptor-Associated Factor 2; Tumor Necrosis Factor-alpha

Paeoniflorin (PF) is one of the main effective components of the total glucosides of peony, which has been reported to have anti-inflammatory ability. However, the effects of paeoniflorin on concanavalin A (Con A)-induced hepatitis have not been carefully examined. The aim of this study was to investigate the protective effect of paeoniflorin and elucidate potential mechanisms of paeoniflorin on Con A-induced hepatitis. C57BL/6 mice were divided randomly into the following four experimental groups: PBS group, PF group, Con A group, and Con A+PF group. Mice received paeoniflorin (50mg/kg) by tail vein before Con A intravenous administration. We found that paeoniflorin pretreatment can significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, paeoniflorin pretreatment suppressed the secretion of proinflammatory cytokines (TNF-α, INF-γ, IL-6), compared with Con A group. Meanwhile, paeoniflorin pretreatment decreased CD4(+), CD8(+) and NKT cell infiltration in the liver. Besides, we observed that paeoniflorin pretreatment can decrease the expression level of Toll-like receptor (TLR) 4 mRNA or protein in liver tissues. Further results showed that paeoniflorin pretreatment was capable of suppressing the activation of the NF-κB pathway by inhibiting IκBα kinase and p65 phosphorylation in Con A-induced liver injury. These results suggest that paeoniflorin pretreatment protects mice against Con A-induced liver injury via inhibition of several inflammatory mediators and, at least in part, by suppressing CD4(+), CD8(+) and NKT cell infiltration in liver. The beneficial effect of paeoniflorin may be related to the downregulation of TLR4 expression and the inhibition of NF-κB activation.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Movement; Concanavalin A; Cytokines; Glucosides; Hepatitis; Inflammation Mediators; Liver; Male; Mice; Mice, Inbred C57BL; Monoterpenes; NF-kappa B; Paeonia; Signal Transduction; T-Lymphocytes; Toll-Like Receptor 4; Transaminases

Immunosuppressive CD11b(+) Gr-1(+) myeloid-derived suppressor cells (MDSCs) accumulate in the livers of tumor-bearing (TB) mice. We studied hepatic MDSCs in two murine models of immune-mediated hepatitis. Unexpectedly, treatment of TB mice with Concanavalin A (Con A) or α-galactosylceramide resulted in increased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) serum levels in comparison to tumor-free mice. Adoptive transfer of hepatic MDSCs into naïve mice exacerbated Con A induced liver damage. Hepatic CD11b(+) Gr-1(+) cells revealed a polarized proinflammatory gene signature after Con A treatment. An IFN-γ-dependent upregulation of CD40 on hepatic CD11b(+) Gr-1(+) cells along with an upregulation of CD80, CD86, and CD1d after Con A treatment was observed. Con A treatment resulted in a loss of suppressor function by tumor-induced CD11b(+) Gr-1(+) MDSCs as well as enhanced reactive oxygen species (ROS)-mediated hepatotoxicity. CD40 knockdown in hepatic MDSCs led to increased arginase activity upon Con A treatment and lower ALT/AST serum levels. Finally, blockade of arginase activity in Cd40(-/-) tumor-induced myeloid cells resulted in exacerbation of hepatitis and increased ROS production in vivo. Our findings indicate that in a setting of acute hepatitis, tumor-induced hepatic MDSCs act as proinflammatory immune effector cells capable of killing hepatocytes in a CD40-dependent manner.

Topics: Adoptive Transfer; Alanine Transaminase; Animals; Antigens, CD1d; Arginase; Aspartate Aminotransferases; B7-1 Antigen; B7-2 Antigen; CD11b Antigen; CD40 Antigens; Cell Line; Concanavalin A; Female; Galactosylceramides; Hepatitis; Hepatocytes; Liver; Liver Neoplasms; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Myeloid Cells; Reactive Oxygen Species; Receptors, Chemokine

To investigate the effects of emodin on concanavalin A (Con A)-induced hepatitis in mice and to elucidate its underlying molecular mechanisms.. A fulminant hepatitis model was established successfully by the intravenous administration of Con A (20 mg/kg) to male Balb/c mice. Emodin was administered to the mice by gavage before and after Con A injection. The levels of pro-inflammatory cytokines and chemokines, numbers of CD4(+) and F4/80(+) cells infiltrated into the liver, and amounts of phosphorylated p38 MAPK and NF-κB in mouse livers and RAW264.7 and EL4 cells were measured.. Pretreatment with emodin significantly protected the animals from T cell-mediated hepatitis, as shown by the decreased elevations of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as well as reduced hepatic necrosis. In addition, emodin pretreatment markedly reduced the intrahepatic expression of pro-inflammatory cytokines and chemokines, including tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-1β, IL-6, IL-12, inducible nitric oxide synthase (iNOS), integrin alpha M (ITGAM), chemokine (C-C motif) ligand 2 (CCL2), macrophage inflammatory protein 2 (MIP-2) and chemokine (CXC motif) receptor 2 (CXCR2). Furthermore, emodin pretreatment dramatically suppressed the numbers of CD4(+) and F4/80(+) cells infiltrating into the liver as well as the activation of p38 MAPK and NF-κB in Con A-treated mouse livers and RAW264.7 and EL4 cells.. The results indicate that emodin pretreatment protects against Con A-induced liver injury in mice; these beneficial effects may occur partially through inhibition of both the infiltration of CD4(+) and F4/80(+) cells and the activation of the p38 MAPK-NF-κB pathway in CD4(+) T cells and macrophages.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; CD11b Antigen; CD4-Positive T-Lymphocytes; Cell Line; Chemokines; Concanavalin A; Cytokines; Emodin; Hepatitis; Liver; Male; Mice; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Protective Agents; Signal Transduction

This study was designed to study the protective effects and mechanisms of N-acetylcysteine (NAC) in concanavalin A-induced hepatitis in mice. In this study, pretreatment with NAC ameliorated the histopathological changes and suppressed inflammatory cytokines in ConA-induced hepatitis. The expression of IL-2, IL-6, TNF-α, and IFN-γ was significantly reduced in the NAC-treated groups. NAC activated PI3K/Akt pathway and inhibited the activation of NF-κB. Additionally, NAC reduced autophagosome formation, as assessed by detecting the expression of LC3 and Beclin 1. Our results demonstrate that NAC can alleviate ConA-induced hepatitis by regulating the PI3K/Akt pathway and reducing the late stages of autophagy. Our results described a new pharmaceutical to provide more effective therapies for immune hepatitis.

Topics: Acetylcysteine; Alanine Transaminase; Animals; Aspartate Aminotransferases; Concanavalin A; Cytokines; Hepatitis; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; NF-kappa B; Proto-Oncogene Proteins c-akt; Signal Transduction

The intravenous injection of the plant lectin concanavalin A (ConA) is a widely used model for acute immune-mediated hepatitis in mice. In contrast to several other models for acute hepatic damage, ConA-induced injury is primarily driven by the activation and recruitment of T cells to the liver. Hence, the ConA model has unique features with respect to its pathogenesis and important similarities to immune-mediated hepatitis in humans, such as autoimmune hepatitis, acute viral hepatitis or distinct entities of drug toxicity leading to immune activation. However, the ConA model has considerable variability, depending on the preparation of the compound, genetic background of the mice, sex, age and microbial environment of the animal facility barrier. This standard operating procedure (SOP) comprises a detailed protocol for the ConA application, including preparation of ConA working solution, handling of the animals, choice of the appropriate conditions and endpoints, as well as efficient dose-finding.

Topics: Acute Disease; Animals; Concanavalin A; Disease Models, Animal; Guidelines as Topic; Hepatitis; Humans; Laboratory Animal Science; Mice

Autoimmune hepatitis represents a ubiquitous human health problem and has a poor prognosis. Dihydroquercetin (DHQ), a well-known antioxidant, significantly inhibits fulminant hepatitis through anti-oxidant and anti-inflammation mechanisms. In this study, we show that administration of DHQ ameliorated concanavalin A (ConA)-induced mouse liver injury by increasing the survival rate, reducing the serum ALT and AST level, preventing histopathological injuries and decreasing pro-inflammatory cytokine mRNA expression in hepatic tissue. As macrophages/Kupffer cells in oxidative stress and pro-inflammatory mediators play an important role in the pathogenesis of immune-mediated hepatitis, we further exposed mouse RAW264 macrophage cell lines to ConA in vitro and found that DHQ significantly inhibited mRNA expression and secretion of IFN-γ and TNF-α in cell culture supernatant. In addition, DHQ significantly enhanced heme oxygenase-1 (HO-1) expression in a dose- and time-dependent manner via increased Nrf2 expression in cytoplasm and nuclear translocation. Furthermore, DHQ enhanced phosphorylation of three members of the mitogen-activated protein kinase (MAPK) family, and cell treatment with MEK/ERK (PD98059), p38 (SB203580) and JNK (SP600125) inhibitors reduced DHQ-induced HO-1 expression. These results indicate that DHQ possesses hepatoprotective properties against ConA-induced liver injury, which are attributed to its ability to scavenge oxidative stress and to inhibit the release of inflammatory mediators via upregulation of HO-1 activity through the MAPK/Nrf2 signaling pathway in macrophages/Kupffer cells.

Topics: Animals; Antioxidants; Autoimmune Diseases; Cell Line; Concanavalin A; Extracellular Signal-Regulated MAP Kinases; Heme Oxygenase-1; Hepatitis; Humans; Immunity; Interferon-gamma; Macrophages; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Models, Animal; NF-E2-Related Factor 2; Quercetin; Signal Transduction; Tumor Necrosis Factor-alpha

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

The extract of Tupistra chinensis (TCE) is traditionally used for the treatment of inflammatory diseases in southwestern China for hundreds of years. The present study was designed to investigate the effects of the TCE against experimental hepatitis and to illustrate its potential mechanisms.. Effects of TCE were investigated on Con A-induced hepatitis. Profiles of multiple cytokines were measured with biometric immuno-sandwich ELISA. Proliferation, activation and apoptosis of T lymphocytes were evaluated using Western blot, MTT analysis and flow cytometry.. TCE significantly inhibited levels of serum transaminases and lactic dehydrogenase in mice with Con A-induced hepatitis, accompanied with marked alleviation of the liver microscopic appearances. Moreover, it decreased levels of inflammatory cytokines in a concentration-dependent manner both in vivo and in vitro. It also suppressed mitogen-activated protein kinases and NF-κB-signalling in liver. These effects of TCE are attributed to its inhibition on activated T cells but not to hepatocytes protection. Flow cytometry and immunoblot assay data showed its effects on STAT1/NF-κB-signalling blockage and apoptosis induction in activated T cells.. Our findings illustrate the significant potential of TCE as a novel approach for treatment of T cell-mediated inflammatory diseases.

Topics: Animals; Apoptosis; Concanavalin A; Cytokines; Female; Hepatitis; Hepatocytes; Inflammation Mediators; Liliaceae; Liver; Medicine, Chinese Traditional; Mice; Mice, Inbred ICR; Mitogen-Activated Protein Kinases; NF-kappa B; Oxidoreductases; Phytotherapy; Plant Extracts; STAT1 Transcription Factor; T-Lymphocytes; Transaminases

T cell immunoglobulin- and mucin-domain-containing molecule-3 (Tim-3) is a negative regulator of interferon (IFN)-γ-secreting CD4(+) Th1 cells and plays a key role in autoimmune diseases. Here, we report that galectin-9 expression was increased in hepatic CD4(+)CD25(+) T cells in a mouse model of concanavalin A (Con A)-induced hepatitis. Moreover, Tim-3 showed increased levels in CD4(+)CD25(+) Foxp3(+) regulatory T cells (Tregs). Further analyses showed that blocking the Tim-3/galectin-9 pathway resulted in the suppression of Tregs in vitro, thereby significantly increasing interferon (IFN)-γ production from hepatic Teffs. Moreover, blockade of Tim-3 in vivo with an anti-Tim-3 antibody exacerbated the acute hepatitis, possibly by increased IFN-γ production. Furthermore, we found that in vitro activation of CD4(+)CD25(-) T cells with the T cell receptor (TCR) plus interleukin 2 (IL-2) up-regulated Tim-3 expression. And the induced Tim-3 interacted with galectin-9 to induce CD4(+) T cell apoptosis which could be partly reversed by blocking Tim-3 signaling. Our results suggested that the Tim-3/galectin-9 pathway plays a critical role in the homeostasis of hepatic Tregs through the elimination induction in Teffs and the inhibition of IFN-γ release, which contributes to the pathogenesis of liver damage and constitutes at least part of the mechanism underlying the induction of hepatitis by Con A.

Topics: Animals; Antibodies, Blocking; Apoptosis; CD4 Antigens; Concanavalin A; Forkhead Transcription Factors; Galectins; Hepatitis; Hepatitis A Virus Cellular Receptor 2; Interferon-gamma; Interleukin-2; Interleukin-2 Receptor alpha Subunit; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Receptors, Antigen, T-Cell; Receptors, Virus; T-Lymphocytes, Regulatory; Th1 Cells

Salidroside, isolated from the medicinal plant Rhodiola, was reported to serve as an "adaptogen." This study was designed to explore the protective effect of salidroside on concanavalin A- (Con A-) induced hepatitis in mice and investigate potential mechanisms. C57BL/6 mice were randomly divided into control group, Con A group, and salidroside group. Salidroside (50 mg/kg) was injected intravenously followed by Con A administration. The levels of ALT, AST, inflammatory cytokines and CXCL-10 were examined. The pathological damage of livers was assessed, the amounts of phosphorylated IκBα and p65 were measured, and the numbers of CD4(+) and CD8(+) T lymphocytes in the blood, spleen and infiltrated in the liver were calculated. Our results showed that salidroside pretreatment reduced the levels of ALT, AST dramatically and suppressed the secretion of proinflammatory cytokines through downregulating the activity of NF-κB partly. Salidroside altered the distribution of CD4(+) and CD8(+) T lymphocyte in the liver and spleen through regulating CXCL-10 and decreased the severity of liver injuries. In conclusion, these results confirm the efficacy of salidroside in the prevention of immune mediated hepatitis in mice.

Topics: Animals; Cell Movement; Concanavalin A; Cytokines; Flow Cytometry; Glucosides; Hepatitis; Lymphocytes; Male; Mice; Mice, Inbred C57BL; Phenols

Immune response plays an important role in the development of hepatic fibrosis. In the present study, we investigated the effects of quercetin on hepatitis and hepatic fibrosis induced by immunological mechanism. In the acute hepatitis model, quercetin (2.5 mg/kg) was injected iv into mice 30 min after concanavalin A (Con A) challenge. Mice were sacrificed 4 or 24 h after Con A injection, and aminotransferase tests and histopathological sections were performed. Treatment with quercetin significantly decreased the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Consistent with this observation, treatment with quercetin markedly attenuated the pathologic changes in the liver. A hepatic fibrosis model was also generated in mice by Con A challenge once a week for 6 consecutive weeks. Mice in the experimental group were treated with daily iv injections of quercetin (0.5 mg/kg). Histopathological analyses revealed that treatment with quercetin markedly decreased collagen deposition, pseudolobuli development, and hepatic stellate cells activation. We also examined the effects of quercetin on the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor beta (TGF-β) pathways by immunohistochemistry and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). NF-κB and TGF-β production was decreased after treatment with quercetin, indicating that the antifibrotic effect of quercetin is associated with its ability to modulate NF-κB and TGF-β production. These results suggest that quercetin may be an effective therapeutic strategy in the treatment of patients with liver damage and fibrosis.

Topics: Alanine Transaminase; Animals; Antioxidants; Aspartate Aminotransferases; Collagen; Concanavalin A; Disease Models, Animal; Female; Hepatic Stellate Cells; Hepatitis; Liposomes; Liver Cirrhosis; Mice, Inbred BALB C; Mitogens; NF-kappa B; Quercetin; Reverse Transcriptase Polymerase Chain Reaction; Transforming Growth Factor beta

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

Ellagic acid (EA) is present in certain fruits and nuts, including raspberries, pomegranates, and walnuts, and has anti-inflammatory and antioxidant properties. The aims of this study were to examine the protective effect of EA on concanavalin A (Con A)-induced hepatitis and to elucidate its underlying molecular mechanisms in mice. Mice were orally administered EA at different doses before the intravenous delivery of Con A; the different experimental groups were as follows: (i) vehicle control, (ii) Con A alone without EA, (iii) EA at 50 mg/kg, (iv) EA at 100 mg/kg, and (v) EA at 200 mg/kg. We found that EA pretreatment significantly reduced the levels of plasma aminotransferase and liver necrosis in Con A-induced hepatitis. Also, EA significantly decreased the expression levels of the toll-like receptor 2 (TLR2) and TLR4 mRNA and protein in liver tissues. Further, EA decreased the phosphorylation of JNK, ERK1/2, and p38. EA-treated groups showed suppressions of nuclear factor κB (NF-κB) and IκB-α degradation levels in liver tissues. In addition, EA pretreatment decreased the expression of pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β). These results suggest that EA protects against T-cell-mediated hepatitis through TLR and mitogen-activated protein kinase (MAPK)/NF-κB signaling pathways.

Topics: Animals; Concanavalin A; Ellagic Acid; Hepatitis; Humans; Male; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; NF-kappa B; Phosphorylation; Protective Agents; Signal Transduction; Toll-Like Receptor 2; Toll-Like Receptor 4

Hydrogen sulfide (H2S) is known to exert anti-inflammatory properties. Apoptosis and autophagy play important roles in concanavalin A (Con A)-induced acute hepatitis. The purpose of this study was to explore both the effect and mechanism of H2S on Con A-induced acute hepatitis.. BALB/c mice were randomized into sham group, Con A-injection group, and 14 μmol/kg of sodium hydrosulfide (NaHS, an H2S donor) pretreatment group.. Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by NaHS pretreatment. NaHS pretreatment significantly reduced the levels of interleukin-6 and tumor necrosis factor-α compared with those of the Con A group. The expression of Bcl-2, Bax, Beclin-1, and LC3-2, which play important roles in the apoptosis and autophagy pathways, were also clearly affected by NaHS. Furthermore, NaHS affected the p-mTOR and p-AKT.. H2S attenuates Con A-induced acute hepatitis by inhibiting apoptosis and autophagy, in part, through activation of the PtdIns3K-AKT1 signaling pathway.

Topics: Acute Disease; Animals; Apoptosis; Autophagy; Concanavalin A; Dose-Response Relationship, Drug; Hepatitis; Hydrogen Sulfide; Injections, Intravenous; Male; Mice; Mice, Inbred BALB C; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction

We investigated the effect of large (40 nm) graphene quantum dots (GQDs) in concanavalin A (Con A; 12 mg/kg i.v.)-induced mouse hepatitis, a T cell-mediated liver injury resembling fulminant hepatitis in humans. Intravenously injected GQDs (50 mg/kg) accumulated in liver and reduced Con A-mediated liver damage, as demonstrated by histopathological analysis and a decrease in liver lipid peroxidation and serum levels of liver transaminases. The cleavage of apoptotic markers caspase-3/PARP and mRNA levels of proapoptotic mediators Puma, Noxa, Bax, Bak1, Bim, Apaf1, and p21, as well as LC3-I conversion to autophagosome-associated LC3-II and expression of autophagy-related (Atg) genes Atg4b, Atg7, Atg12, and beclin-1, were attenuated by GQDs, indicating a decrease in both apoptosis and autophagy in the liver tissue. This was associated with the reduced liver infiltration of immune cells, particularly the T cells producing proinflammatory cytokine IFN-γ, and a decrease in IFN-γ serum levels. In the spleen of GQD-exposed mice, mRNA expression of IFN-γ and its transcription factor T-bet was reduced, while that of the IL-33 ligand ST2 was increased. The hepatoprotective effect of GQDs was less pronounced in ST2-deficient mice, indicating that it might depend on ST2 upregulation. In vitro, GQDs inhibited splenocyte IFN-γ production, reduced the activation of extracellular signal-regulated kinase in macrophage and T cell lines, inhibited macrophage production of the free radical nitric oxide, and reduced its cytotoxicity toward hepatocyte cell line HepG2. Therefore, GQDs alleviate immune-mediated fulminant hepatitis by interfering with T cell and macrophage activation and possibly by exerting a direct hepatoprotective effect.

Topics: Animals; Apoptosis; Biological Transport; Biomarkers; Cell Line; Concanavalin A; Cytoprotection; Gene Expression Regulation; Graphite; Hepatitis; Humans; Lipid Peroxidation; Male; Mice; Oxidative Stress; Particle Size; Quantum Dots

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

T cell activation and associated pro-inflammatory cytokine production is a pathological feature of inflammatory liver disease. It is also known that liver injury is associated with marked impairments in the function of many hepatic proteins including a hepatocyte-specific binding protein, the asialoglycoprotein receptor (ASGPR). Recently, it has been suggested that hepatic ASGPRs may play an important role in the physiological regulation of T lymphocytes, leading to our hypothesis that ASGPR defects correlate with inflammatory-mediated events in liver diseases. Therefore, in this study we investigated whether changes in hepatocellular ASGPR expression were related to the dysregulation of intrahepatic T lymphocytes and correlate with the development of T-cell mediated hepatitis. Mice lacking functional ASGPRs (receptor-deficient, RD), and wild-type (WT) controls were intravenously injected with T-cell mitogens, Concanavalin A (Con A) or anti-CD3 antibody. As a result of T cell mitogen treatment, RD mice lacking hepatic ASGPRs displayed enhancements in liver pathology, transaminase activities, proinflammatory cytokine expression, and caspase activation compared to that observed in normal WT mice. Furthermore, FACS analysis demonstrated that T-cell mitogen administration resulted in a significant rise in the percentage of CD8+ lymphocytes present in the livers of RD animals versus WT mice. Since these two mouse strains differ only in whether they express the hepatic ASGPR, it can be concluded that proper ASGPR function exerts a protective effect against T cell mediated hepatitis and that impairments to this hepatic receptor could be related to the accumulation of cytotoxic T cells that are observed in inflammatory liver diseases.

Topics: Animals; Antibodies; Asialoglycoprotein Receptor; CD3 Complex; Concanavalin A; Cytokines; Female; Hepatitis; Leukocyte Common Antigens; Mice; Mice, Knockout; Mitogens; T-Lymphocyte Subsets; T-Lymphocytes

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

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

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

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

Peroxisome proliferator-activated receptor-α (PPARα) is physiologically highly expressed by hepatocytes, where it plays a pivotal anti-inflammatory and metabolic role. The decrease expression and functional activity of PPARα in hepatocytes during hepatitis C virus infection may contribute to the pathogenesis of the disease in humans. This study aims at evaluating the effects of PPARα activation with fenofibrate (FF) on liver inflammation, fibrosis and portal pressure (PP) in Concanavalin A (Con A)- induced hepatitis in rats. The rats were randomly divided to 3 groups; control (1 ml saline iv/wk) group, Con A (20mg/kg/iv/wk) group and Con A with FF (100mg/kg/day p.o) group. Blood samples and livers were collected by the end of the first, second, fourth and eighth injections of Con A for biochemical, histopathological and immunohistochemistry studies for α-smooth muscle actin (α SMA). Measurement of PP was performed by the end of the 8th week. FF group had a significant (P<0.05) decrease of serum alanine and aspartate aminotransferases with significant reduction of hepatic tumor necrosis factor alpha and malondialdehyde levels than Con A group. Histopathological examination revealed that treatment with FF significantly suppressed early inflammation, reduced α SMA, and apoptosis of hepatocytes induced by Con A, thereby preventing the progression of chronic liver injury and fibrosis. In addition FF group had a significantly lower PP (-89.0%) than Con A group. In conclusion PPARα activation significantly reduced liver inflammation, fibrosis and PP in Con A model of hepatitis that may represent a new therapeutic strategy for hepatitis and its complications.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Biomarkers; Concanavalin A; Fenofibrate; Hepatitis; Liver; Male; Malondialdehyde; Oxidative Stress; Portal Pressure; PPAR alpha; Rats; Rats, Wistar; 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

Mild hypothermia (32-33°C) shows protective effects in patients with brain damage and cardiac arrest. Although cold-inducible RNA-binding protein (CIRP) contributes to the protective effects of hypothermia through extracellular signal-regulated kinase activation in fibroblasts, the effects of hypothermia in the liver remain unclear.. We analysed the effects of cold temperature on fulminant hepatitis, a potentially fatal disease, using the D-galactosamine (GalN)/lipopolysaccharide (LPS) and concanavalin (con) A-induced hepatitis models in mice. After GalN/LPS administration and anaesthesia, mice in the hypothermia group were kept at 25°C and those in control group were kept at 35°C. After concanavalin A (con A) administration, the mice in the hypothermia group were placed in a chamber with an ambient temperature of 6°C for 1.5 h.. Hypothermia attenuated liver injury and prolonged survival. Activation of c-Jun N-terminal kinase and Akt, which are involved in reactive oxygen species (ROS) accumulation, was suppressed by low temperature. Hypothermia significantly decreased oxidized protein levels, and treatment with N-acetyl-L-cysteine, an antioxidant, attenuated GalN/LPS-induced liver injury. In con A-induced hepatitis, CIRP expression was upregulated and Bid expression was downregulated, resulting in decreased apoptosis of hepatocytes in the hypothermia group.. These data suggest that hypothermia directly protects hepatocytes from cell death via reduction of ROS production in fulminant hepatitis.

Topics: Animals; Cell Death; Cold Temperature; Concanavalin A; Galactosamine; HeLa Cells; Hepatitis; Humans; Hypothermia, Induced; Lipopolysaccharides; Liver; Mice; Mice, Inbred C57BL; Reactive Oxygen Species; RNA-Binding Proteins; Tumor Necrosis Factor-alpha; Up-Regulation

The aims of this study were to examine the anti-inflammatory effect of curcumin on concanavalin A (ConA) induced hepatitis in mice, and to elucidate its underlying molecular mechanisms. Mice received curcumin by gavage before ConA intravenous administration. The results showed that curcumin pretreatment attenuated ConA-induced hepatitis. Enzyme linked immunosorbent assay (ELISA) results showed that serum levels of high mobility group box 1 (HMGB1) increased at 4 h and reached its peak value at 12 h after challenge with ConA; but this increase was significantly inhibited by curcumin. Furthermore, curcumin significantly decreased the HMGB1 translocation from nucleus to cytoplasm of hepatocytes in ConA-induced mice. The levels of HMGB1 mRNA and protein expression in the liver were also significantly lowered in curcumin-treated mice. In addition, curcumin inhibited intrahepatic expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 protein. In conclusion, the results indicated that curcumin protected against ConA-induced hepatitis in mice; and the beneficial effects may be partly through inhibition of HMGB1 translocation in hepatocytes, release into the plasma and expression in livers.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Concanavalin A; Curcumin; Hepatitis; HMGB1 Protein; Interleukin-1beta; Interleukin-6; Liver; Male; Mice; Mice, Inbred BALB C; Protein Transport; RNA, Messenger; Transaminases; Tumor Necrosis Factor-alpha

Our aim was to evaluate the therapeutic effects of bone-marrow-derived mesenchymal stem cells (BMMSCs) on ConA-induced hepatitis and to elucidate the possible mechanism involved. MSCs were isolated from bone marrow and their characteristics and anti-apoptotic effects on the L02 cell line were analyzed. The effect of intravenous infusion of BMMSCs on liver damage was also tested. Furthermore, the recruitment of donor BMMSCs to the liver of recipient animals and their effects on the activity of intrahepatic natural killer T (NKT) cells were investigated. BMMSCs ameliorated liver damage in a time- and dose-dependent manner. Donor BMMSCs were detected in the livers of recipient animals, suggesting that tissue damage stimulated the migration of BMMSCs. Transplanted BMMSCs also suppressed the activity of intrahepatic NKT cells, not only in the liver but throughout the body. The general infusion of BMMSCS ameliorated immunoregulatory activities by the suppression of intrahepatic NKT cells.

Topics: Acute Disease; Animals; Apoptosis; Bone Marrow Cells; Cell Movement; Cell Proliferation; Concanavalin A; Culture Media, Conditioned; Cytokines; Cytoprotection; Disease Models, Animal; Female; Hepatitis; Humans; Hydrogen Peroxide; Inflammation; Inflammation Mediators; Liver; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Inbred C57BL; Natural Killer T-Cells

Nephronectin (Npnt) is an extracellular matrix protein known to play a critical role in kidney development; however, its physiological role in the liver remains elusive. Here we show that Npnt expression is upregulated in mouse models of both acute and chronic hepatitis induced by Concanavalin A (Con A) and 3,5-diethocarbonyl-1,4-dihydrocollidine (DDC), respectively. In both models, Npnt was localized in inflammatory foci and was mainly secreted from mesenchymal cells and in part by cholangiocytes. Interestingly, ectopic expression of Npnt in hepatocytes induced the development of granuloma-like cell clusters mainly composed of CD4(+) T cells or NKT cells but did not induce apparent hepatitis. Furthermore, we found that Npnt exacerbated the Con A-induced acute hepatitis. These results indicate that Npnt plays an important role in the initiation of hepatitis by recruiting CD4(+) T cells or NKT cells into the foci of inflammation. In addition, we reveal that Npnt expression is also upregulated in human hepatitis. Therefore, Npnt may be a potential therapeutic target for acute and chronic hepatitis.

Topics: Acute Disease; Animals; CD4-Positive T-Lymphocytes; Cell Movement; Concanavalin A; Disease Models, Animal; Disease Progression; Extracellular Matrix Proteins; Gene Expression Regulation; Granuloma; Hepatitis; Hepatitis, Chronic; Liver; Male; Mice; Mice, Inbred C57BL; Up-Regulation

Concanavalin A (Con A)-induced hepatitis is thought to be a T-cell-mediated disease with active destruction of liver cells. Interleukin (IL)-17 is a cytokine produced principally by CD4(+) T cells. However, whether IL-17/IL-17 receptor (IL-17/IL-17R)-mediated responses are involved in T-cell-mediated Con A-induced liver injury remains unclear. In this study, we found that IL-17 expression was highly elevated in liver tissues during Con A-induced hepatitis. The increased levels of IL-17 were paralleled with the severity of liver injury reflected by Alanine aminotransaminase and histological assay as well as the secretion of tumor necrosis factor (TNF)-α and IL-6. Blockage of IL-17 significantly ameliorated Con A-induced hepatitis, while overexpression of IL-17 systemically resulted in massive hepatocyte necrosis in mice. Furthermore, overexpression of an IL-17R immunoglobulin G1 fusion protein significantly attenuated liver inflammation after acute Con A treatment. High expression of IL-17R on Kupffer cells was also observed along with the production of cytokines including TNF-α and IL-6. Inhibition of Kupffer cells by gadolinium chloride completely prevented Con A-induced liver injury and cytokine release. Finally, IL-17-expressing CD4(+) T and natural killer T cells were greatly increased in Con A-injected mice compared with that in controls. Overall, our results indicate that IL-17R signaling is critically involved in the pathogenesis in Con A-induced hepatitis, and blockade of IL-17/IL-17R signaling pathway may represent a novel therapeutic intervention in human autoimmune-related hepatitis.

Topics: Animals; CD4-Positive T-Lymphocytes; Concanavalin A; Hepatitis; Humans; Immunoglobulin G; Inflammation; Interleukin-17; Kupffer Cells; Liver; Mice; Receptors, Interleukin-17; Signal Transduction

Topics: Animals; Concanavalin A; Hepatitis; Humans; Interleukin-17; Receptors, Interleukin-17

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

Membrane microdomains consisting of sphingomyelin (SM) and cholesterol appear to be important for signal transduction in T-cell activation. The present study was designed to elucidate the role of membrane SM in vivo and in vitro using sphingomyelin synthase 1 (SMS1) knock out (SMS1(-/-)) mice and Concanavalin A (ConA)-induced hepatitis. After establishing SMS1(-/-) mice, we investigated CD4+ T-cell functions including proliferation, cytokine production and signal transduction in vivo. We also examined severity of hepatitis, cytokine production in serum and liver after ConA injection at a dose of 20 mg kg(-1). CD4+ T cells from SMS1(-/-) mice showed severe deficiency of membrane SM and several profound defects compared with wild-type controls as follows: (i) cellular proliferation and production of IL-2 and IFN-γ by co-cross-linking of CD3 and CD4; (ii) tyrosine phosphorylation of LAT and its association with ZAP-70; (iii) clustering and co-localization of TCR with lipid rafts. Consistent with these impaired CD4+ T-cell functions in vitro, SMS1(-/-) mice showed decreased serum levels of IL-6 and IFN-γ by ConA injection, which renders SMS1(-/-) mice less sensitive to ConA-induced hepatitis. These results indicated that the deficiency of membrane SM caused the CD4+ T-cell dysfunction through impaired lipid raft function contributed to protection of ConA-induced liver injury, suggesting that the membrane SM is critical for full T-cell activation both in vitro and in vivo.

Topics: Animals; CD4-Positive T-Lymphocytes; Concanavalin A; Hepatitis; Membrane Microdomains; Mice; Mice, Inbred C57BL; Mice, Knockout; Transferases (Other Substituted Phosphate Groups)

Interleukin-1 receptor antagonist (IL-1Ra) is a specific IL-1 inhibitor that possesses anti-inflammatory activities. Several studies in human and mouse suggested a protective role for IL-1Ra in liver inflammation, and we previously demonstrated that hepatocytes produce high levels of IL-1Ra in response to inflammatory challenge in vitro and in vivo. In the present study, we investigated the production and the biological function of hepatocyte-derived IL-1Ra in concanavalin A (ConA)-induced hepatitis in mice. We show that the injured liver produces large amounts of IL-1Ra and that secreted and intracellular IL-1Ra isoforms are produced with different kinetics during the course of hepatitis. By using hepatocyte-specific IL-1Ra-deficient mice (IL-1Ra(ΔH)), we demonstrate that hepatocytes represent the major cellular source of local IL-1Ra. Most interestingly, hepatic necrosis and inflammation were increased in IL-1Ra(ΔH) as compared with wild-type mice during the late phase of the disease, leading to a delayed resolution of hepatitis in IL-1Ra(ΔH) mice. In conclusion, our results show that the local production of IL-1Ra by hepatocytes contributes to the resolution of hepatitis.

Topics: Animals; Concanavalin A; Cytokines; Hepatitis; Hepatocytes; Interleukin 1 Receptor Antagonist Protein; Liver; Male; Mice; Mice, Inbred C57BL; Necrosis

Retinoic acid (RA) is a diverse regulator of immune responses. Although RA promotes natural killer T (NKT) cell activation in vitro by increasing CD1d expression on antigen-presenting cells (APCs), the direct effects of RA on NKT-cell responses in vivo are not known. In the present study, we demonstrated the effect of RA on the severity of Con A-induced hepatitis and molecular changes of NKT cells. First, we demonstrated that Con A-induced liver damage was ameliorated by RA. In correlation with cytokine levels in serum, RA regulated the production of IFN-γ and IL-4 but not TNF-α by NKT cells without influencing the NKT-cell activation status. However, RA did not alleviate α-GalCer-induced liver injury, even though it reduced IFN-γ and IL-4 but not TNF-α levels in serum. This regulation was also detected when liver mononuclear cells (MNCs) or NKT hybridoma cells were treated with RA in vitro. The regulatory effect of RA on NKT cells was mediated by RAR-α, and RA reduced the phosphorylation of MAPK. These results suggest that RA differentially modulates the production of effector cytokines by NKT cells in hepatitis, and the suppressive effect of RA on hepatitis varies with the pathogenic mechanism of liver injury.

Topics: Animals; Blotting, Western; Concanavalin A; Disease Models, Animal; Female; Galactosylceramides; Gene Expression Regulation; Hepatitis; Interferon-gamma; Interleukin-4; Kaplan-Meier Estimate; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Natural Killer T-Cells; Real-Time Polymerase Chain Reaction; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; RNA; Specific Pathogen-Free Organisms; Tretinoin; Tumor Necrosis Factor-alpha

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

Selectively facilitating apoptosis of activated T cells is essential for the clearance of pathogenic injurious cells and subsequent efficient resolution of inflammation. However, few chemicals have been reported to trigger apoptosis of activated T cells for the treatment of hepatitis without affecting quiescent T cells. In the present study, we found that asiatic acid, a natural triterpenoid, selectively triggered apoptosis of concanavalin A (Con A)-activated T cells in a mitochondria-dependent manner indicated by the disruption of the mitochondrial transmembrane potential, release of cytochrome c from mitochondria to cytosol, caspases activation, and cleavage of PARP. In addition, asiatic acid also induced the cleavage of caspase 8 and Bid and augmented Fas expression in Con A-activated T cells. However, following activation of T cells from MRL(lpr/lpr) mice with mutation of Fas demonstrated a similar susceptibility to asiatic acid-induced apoptosis compared with normal T cells, suggesting that Fas-mediated death-receptor apoptotic pathway does not mainly contribute to asiatic acid-induced cell death. Furthermore, asiatic acid significantly alleviated Con A-induced T cell-dependent fulminant hepatitis in mice, as assessed by reduced serum transaminases, pro-inflammatory cytokines, and pathologic parameters. Consistent with the in vitro results, asiatic acid also induced apoptosis of activated CD4(+) T cells in vivo. Taken together, our results demonstrated that the ability of asiatic acid to induce apoptosis of activated T cells and its potential use in the treatment of T-cell-mediated inflammatory diseases.

Topics: Animals; Apoptosis; Caspases; Cell Proliferation; Concanavalin A; Enzyme Activation; Female; Hepatitis; Liver; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mitochondria; Pentacyclic Triterpenes; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; T-Lymphocytes

T cell-mediated liver damage is a key event in the pathogenesis of many chronic human liver diseases, such as liver transplant rejection, primary biliary cirrhosis, and sclerosing cholangitis. We and other groups have previously reported that galectin-9, one of the β-galactoside binding animal lectins, might be potentially useful in the treatment of T cell-mediated diseases. To evaluate the direct effect of galectin-9 on hepatitis induced by concanavalin A (Con A) administration in mice and to clarify the mechanisms involved, we administered galectin-9 into mice, and evaluated its therapeutic effect on Con A-induced hepatitis.. Galectin-9 was administrated i.v. to Balb/c mice 30 min before Con A injection. Compared with no treatment, galectin-9 pretreatment significantly reduced serum ALT and AST levels and improved liver histopathology, suggesting an ameliorated hepatitis. This therapeutic effect was not only attributable to a blunted Th1 immune response, but also to an increased number in regulatory T cells, as reflected in a significantly increased apoptosis of CD4(+)CD25(low/int) effector T cells and in reduced proinflammatory cytokine levels.. Our findings constitute the first preclinical data indicating that interfering with TIM-3/galectin-9 signaling in vivo could ameliorate Con A-induced hepatitis. This strategy may represent a new therapeutic approach in treating human diseases involving T cell activation.

Topics: Animals; Apoptosis; CD4 Lymphocyte Count; Concanavalin A; Cytokines; Galectins; Hepatitis; Interleukin-2 Receptor alpha Subunit; Mice; Mice, Inbred BALB C; T-Lymphocytes, Regulatory

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

The chemokine receptor CXCR3 is preferentially expressed by Th1 cells and critically involved in their recruitment to inflamed tissue. In a mouse model of immune-mediated liver injury inducible by Con A, we investigated the role of CXCR3 in acute IFN-γ-mediated hepatitis as well as in tolerance induction, which has been shown to depend on IL-10-producing CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs). Induction of Con A hepatitis resulted in increased intrahepatic expression of the CXCR3 ligands CXCL9, CXCL10, and CXCL11. CXCR3(-/-) mice developed a more severe liver injury with higher plasma transaminase activities and a more pronounced Th1/Th17 response compared with wild-type (wt) animals upon Con A injection. Moreover, CXCR3(-/-) mice did not establish tolerance upon Con A restimulation, although Tregs from CXCR3(-/-) mice were still suppressive in an in vitro suppression assay. Instead, Tregs failed to accumulate in livers of CXCR3(-/-) mice upon Con A restimulation in contrast to those from wt animals. Con A-tolerant wt mice harbored significantly increased numbers of intrahepatic CXCR3(+)T-bet(+) Tregs that produced IL-10 compared with nontolerant animals. IFN-γ deficiency or anti-IFN-γ Ab treatment demonstrated that conversion to CXCR3(+)T-bet(+) Tregs depended on a Th1 response. Accordingly, in an immunotherapeutic approach, CD4(+)CD25(+)Foxp3(+) Tregs from Con A-pretreated CXCR3-deficient mice failed to protect against Con A-induced hepatitis, whereas Tregs from Con A-tolerant wt mice allowed CXCR3-deficient mice to recover from Con A hepatitis. In summary, CXCR3(+)T-bet(+)IL-10(+) Tregs are generated in the liver in dependence of IFN-γ, then disseminated into the organism and specifically migrate into the liver, where they limit immune-mediated liver damage.

Topics: Animals; Cell Separation; Concanavalin A; Flow Cytometry; Hepatitis; Immune Tolerance; Interferon-gamma; Male; Mice; Mice, Inbred C57BL; Mitogens; Receptors, CXCR3; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes, Regulatory

The Gi protein-associated A(3) adenosine receptor (A(3) AR) is a member of the adenosine receptor family. Selective agonists at the A(3) AR, such as CF101 and CF102 were found to induce anti-inflammatory and anti-cancer effects. In this study, we examined the differential effect of CF102 in pathological conditions of the liver. The anti-inflammatory protective effect of CF101 was tested in a model of liver inflammation induced by Concanavalin A (Con. A) and the anti-cancer effect of CF102 was examined in vitro and in a xenograft animal model utilizing Hep-3B hepatocellular carcinoma (HCC) cells. The mechanism of action was explored by following the expression levels of key signaling proteins in the inflamed and tumor liver tissues, utilizing Western blot (WB) analysis. In the liver inflammation model, CF102 (100 µg/kg) markedly reduced the secretion of serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase in comparison to the vehicle-treated group. Mechanistically, CF102 treatment decreased the expression level of phosphorylated glycogen synthase kinase-3β, NF-κB, and TNF-α and prevented apoptosis in the liver. This was demonstrated by decreased expression levels of Fas receptor (FasR) and of the pro-apoptotic proteins Bax and Bad in liver tissues. In addition, CF102-induced apoptosis of Hep-3B cells both in vitro and in vivo via de-regulation of the PI3K-NF-κB signaling pathway, resulting in up-regulation of pro-apoptotic proteins. Taken together, CF102 acts as a protective agent in liver inflammation and inhibits HCC tumor growth. These results suggest that CF102 through its differential effect is a potential drug candidate to treat various pathological liver conditions.

Topics: Adenosine; Adenosine A3 Receptor Agonists; Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Concanavalin A; Hepatitis; Liver; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Receptor, Adenosine A3; Signal Transduction; Xenograft Model Antitumor Assays

The effect of curcumin on liver injury caused by Concanavalin A (Con A) has not been carefully examined. This study was designed to evaluate the protective effect of curcumin on Con A-induced hepatitis in mice. Liver injured mice received curcumin by gavage at a dose of 200 mg/kg body weight before Con A intravenous administration. Curcumin was effective in reducing the elevated plasma levels of aminotransferases and the incidence of liver necrosis compared with Con A-injected control group. Enzyme-linked immunosorbent assay (ELISA) showed that curcumin suppressed proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-4 production in Con A-injected mice. The reduced severity of hepatitis in curcumin pretreated mice correlated with decrease in numbers of liver CD4(+) T cells but not CD8(+) T cells by immunohistochemical analysis. Furthermore, the expression levels of intercellular adhesion molecule-1 (ICAM-1) and the interferon-inducible chemokine CXCL10 in hepatic tissue were significantly decreased by curcumin pretreatment. In conclusion, curcumin pretreatment protects against T cell-mediated hepatitis in mice.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Movement; Chemokine CXCL10; Concanavalin A; Curcumin; Cytokines; Gene Expression Regulation; Hepatitis; Intercellular Adhesion Molecule-1; Liver; Male; Mice; Mice, Inbred BALB C; Protective Agents; RNA, Messenger

We recently reported that after LPS stimulation, IL-37 translocates to the nucleus and reduces the expression of proinflammatory cytokines. The aim of this study was to investigate whether transiently expressed IL-37 in mice reduces inflammation in concanavalin A (ConA)-induced hepatitis and LPS-induced sepsis. Transgene IL-37 expression was detected in the liver lysate of mice injected with IL-37 plasmid-DNA after hydrodynamic tail vein injection. All mice developed severe acute hepatitis after ConA injection. No difference in the histological score and serum ALT was observed between the two groups that might be explained by patchy expression of IL-37 protein in the liver. However, 2 hrs after ConA injection, serum levels for IL-1α, IL-6, IL-5, and IL-9 were significantly reduced in IL-37-expressing mice as seen for the LPS model. In conclusion, in vivo expression of human IL-37 in mice reduces local and systemic inflammation in ConA-induced hepatitis and LPS challenge.

Topics: Animals; Cloning, Molecular; Concanavalin A; Disease Models, Animal; Female; Gene Expression Regulation; Hepatitis; Immunohistochemistry; Inflammation; Injections, Intravenous; Interleukin-1; Lipopolysaccharides; Liver; Luciferases; Mice; Mice, Inbred C57BL; Plasmids; Sepsis; Time Factors; Transgenes

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

Although B and T lymphocyte attenuator (BTLA) was originally identified as an inhibitory coreceptor selectively expressed on Th1 cells and B cells, recent studies have revealed that BTLA is expressed on a variety of cells, including macrophages, dendritic cells, and NK cells, and modulates their functions. However, the role of BTLA in the regulation of NKT cell function remains unknown. In this study, we found that BTLA was expressed on NKT cells at the levels similar to those on T cells and that BTLA-deficient (BTLA(-/-)) NKT cells produced larger amounts of IL-4 and IFN-gamma upon alpha-glactosylceramide stimulation as compared with wild-type (WT) NKT cells. In vivo, BTLA(-/-) mice produced larger amounts of IL-4 and IFN-gamma upon Con A injection and were more susceptible to Con A-induced hepatitis than WT mice. In addition, the augmentation of Con A-induced hepatitis in BTLA(-/-) mice was not observed in BTLA/NKT-double deficient mice. Moreover, NKT(-/-) mice reconstituted with BTLA(-/-) NKT cells were significantly more susceptible to Con A-induced hepatitis as compared with NKT (-/-) mice reconstituted with WT NKT cells. These results suggest that BTLA functions as the inhibitory coreceptor of NKT cells and plays a critical role in the prevention of NKT cell-mediated liver injury.

Topics: Adoptive Transfer; Animals; Concanavalin A; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Hepatitis; Interferon-gamma; Interleukin-4; Lymphocyte Activation; Mice; Mice, Knockout; Mitogens; Natural Killer T-Cells; Receptors, Immunologic

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

Tim-4 is expressed primarily on APCs, including macrophages, and has been shown to play a critical role in T cell regulation. However, it remains unclear whether Tim-4 also plays a role in the regulation of macrophage functions. In the present study, we investigated the effects of Tim-4 on macrophage activity in Con A-induced hepatitis in mice. We found that high levels of Tim-4 expression were associated with a diminished serum level of ALT in Con A-induced hepatitis. In addition, adoptive transfer of T4-RAW cells resulted in a significant decrease in ALT levels and Con A-induced liver injuries in mice. Concurrently, T4-RAW cells transfer displayed, markedly decreased apoptosis in liver and depressed TNF-alpha secretion in serum, supporting the hypothesis that Tim-4 protects Con A-induced hepatitis by negatively regulating macrophages. Consistent with the in vivo findings, in vitro studies showed that Tim-4 overexpression in RAW264.7 cells was associated with decreased expression of CD80, CD86, and MHCII molecules and the production of TNF-alpha. Moreover, Tim-4 blockade promoted LPS-induced macrophage activation. In conclusion, these findings indicate that Tim-4 plays an important role in alleviating liver damage by inhibition of macrophage activity. Tim-4 pathway could be a potential target for the treatment of acute hepatitis.

Topics: Animals; B7-1 Antigen; B7-2 Antigen; Cell Line; Concanavalin A; Down-Regulation; Hepatitis; Histocompatibility Antigens Class II; Interferon-gamma; Macrophage Activation; Macrophages; Male; Membrane Proteins; Mice; Mice, Inbred BALB C

Administration of attenuated pathogenic T cell clones, a procedure known as T cell vaccination, induces CD8+ T cells specific for peptides derived from the Vbeta-chain of the TCR presented by the MHC class Ib molecule, Qa-1 expressed on the vaccine cells. These regulatory CD8+ T cells have the capacity to control the activation of endogenous T cells expressing the same TCR Vbeta-chain as the vaccinating cells. We hypothesized that vaccination with NKT cells could also induce Qa-1-restricted CD8+ T cells that would control NKT cell activation. We tested this hypothesis in a murine model of Con A-induced hepatitis that is induced by NKT cells. Vaccination with NKT cells effectively induced protective Qa-1-restricted CD8+ T cells that prevented hepatitis. Surprisingly, upon vaccination with T cells expressing Vbeta-chains irrelevant to NKT cells, we discovered that the specificity of vaccine-induced Qa-1-restricted CD8+ T cells was not limited to the Vbeta-chain of the vaccinating cells. We further show that these regulatory Qa-1-restricted CD8+ T cells arise spontaneously upon polyclonal activation of T cells in the absence of deliberate T cell vaccination. These experiments provide new insight into a CD8+ T cell compartment that regulates the immediate reactivation of conventional T cells and NKT cells.

Topics: Adoptive Transfer; Animals; CD8-Positive T-Lymphocytes; Cell Separation; Concanavalin A; Flow Cytometry; Hepatitis; Histocompatibility Antigens Class I; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mitogens; Natural Killer T-Cells; Receptors, Antigen, T-Cell; T-Lymphocyte Subsets; Vaccination

Coinhibitors and costimulators control intrahepatic T cell responses that trigger acute hepatitis. We used the ConA-induced hepatitis model in the mouse to test if the coinhibitor herpes virus entry mediator (HVEM) modulates hepatitis-inducing T cell responses. Compared with ConA-injected, wild-type (wt) C57BL/6 (B6) mice, HVEM-deficient (HVEM(-/-)) B6 mice showed lower serum transaminase levels and lower proinflammatory IFN-gamma, but higher protective IL-22 serum levels and an attenuated liver histopathology. The liver type I invariant NKT cell population that initiates acute hepatitis in this model was reduced in HVEM(-/-) mice but their surface phenotype was similar to that of untreated or ConA-treated wt controls. In response to mitogen injection, liver invariant NKT cells from HVEM(-/-) B6 mice produced in vivo more IL-22 but lower amounts of IFN-gamma and IL-4 than wt controls. Bone marrow chimeras showed that HVEM deficiency of the liver nonparenchymal cell population, but not of the parenchymal cell population, mediated the attenuated course of the dendritic cell- and T cell-dependent ConA hepatitis. IL-22 is produced more efficiently by liver NKT cells from HVEM(-/-) than from wt mice, and its Ab-mediated neutralization of IL-22 aggravated the course of hepatitis in wt and HVEM(-/-) mice. Hence, HVEM expression promotes pathogenic, proinflammatory Th1 responses but down-modulates protective IL-22 responses of T cells in this model of acute hepatitis.

Topics: Animals; Concanavalin A; Hepatitis; Interleukin-22; Interleukins; Mice; Mice, Knockout; Receptors, Tumor Necrosis Factor, Member 14; T-Lymphocytes

The liver has the unique capacity to restore its mass by hepatocyte proliferation after injury or transplantation. The present study investigated whether the regenerating liver responds to immune stimuli in the same way as the quiescent one.. We performed partial hepatectomy (PHx) in mice, then stimulated the mice with concanavalin A (ConA) to study their immune responses. Plasma Alanine aminotransferase (ALT) and cytokine levels as well as liver inflammatory infiltration were measured to evaluate liver damage. Transcriptional factors were further detected to study the underlining mechanisms.. Our results showed that PHx mice were resistant to ConA-induced liver inflammation and injury, as evidenced by both morphological and biochemical observations. Then we went further to study the mechanisms. We found marked signal transducer and activator of transcription 3 (STAT3) activation 48 hours after PHx. When STAT3 activation was blocked with its inhibitor JSI-124, PHx mice also developed severe liver inflammation after ConA stimulation.. The regenerating liver is resistant to ConA induced immune assaulting, and STAT3 is the major player in the protection process.

Topics: Alanine Transaminase; Animals; Concanavalin A; Cytokines; Down-Regulation; Hepatectomy; Hepatitis; Liver; Liver Regeneration; Male; Mice; Mice, Inbred C57BL; STAT3 Transcription Factor; Time Factors

Immune-mediated liver diseases including autoimmune and viral hepatitis are a major health problem worldwide. In this study, we report that activation of the farnesoid X receptor (FXR), a member of the ligand-activated nuclear receptor superfamily and bile sensor highly expressed in the liver, attenuates liver injury in a model of autoimmune hepatitis induced by Con A. We found that FXR gene ablation results in a time-dependent increase of liver expression (up to 20-fold in a 9-mo-old mouse) of osteopontin, a NKT cell-derived extracellular matrix protein and immunoregulatory cytokine. In comparison to wild-type, FXR(-/-) mice are more susceptible to Con A-induced hepatitis and react to Con A administration by an unregulated production of osteopontin. Administering wild-type mice with a synthetic FXR agonist attenuated Con A-induced liver damage and liver expression of the osteopontin gene. By in vitro studies, we found that FXR is expressed by primarily isolated NKT cells and its ablation favors ostepontin production in response to Con A. Chromatin immunoprecipitation assay and coimmunoprecipitation experiments demonstrate that the short heterodimer partner (SHP), a nuclear receptor and FXR target, was expressed by NKT cell hybridomas and increased in response to FXR activation. FXR activates SHP that interacts with and inhibits c-Jun binding to the osteopontin promoter. These data indicate that in NKT cells, FXR activation causes a SHP-mediated inhibition of osteopontin production. These data support the notion that the bile acid sensor FXR regulates the activation of liver NKT cells.

Topics: Acute Disease; Animals; Bile Acids and Salts; Cell Line; Concanavalin A; Hepatitis; Interferon-gamma; Interleukin-4; Liver; Lymphocyte Activation; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogens; Natural Killer T-Cells; Osteopontin; Promoter Regions, Genetic; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; Tumor Necrosis Factor-alpha

Suppressor of cytokine signaling 3 (SOCS3), a negative-feedback molecule for cytokine signaling, has been implicated in protection against liver injury. Previous studies have shown that overexpression of SOCS3 in the liver by adenovirus or membrane permeable recombinant protein protected the liver from various injuries. However it remained uncertain in which type of cells SOCS3 suppresses liver injury. In this study, we demonstrated that forced expression of SOCS3 in T and NKT cells suppressed ConA-induced hepatitis using T and NKT cell-specific SOCS3 transgenic (Lck-SOCS3 Tg) mice. IFN-gamma and IL-4 production was reduced in Lck-SOCS3 Tg mice as well as splenocytes treated with ConA. IFN-gamma and IL-4 levels were also reduced in Lck-SOCS3 Tg mice administrated with alpha-galactosylceramide, suggesting that SOCS3 in NKT cells has suppressive function. Sustained expression of SOCS3 in an NKT cell line also resulted in reduced expression of various cytokines and transcription factors. In contrast, T and NKT cell-specific SOCS3 conditional knockout (Lck-SOCS3 cKO) mice were hypersensitive to ConA-mediated hepatitis. Isolated SOCS3-deficient NKT cells produced higher levels of IFN-gamma and IL-4. These data indicate that SOCS3 plays a negative regulatory role in NKT cell activation and that forced expression of SOCS3 in NKT cells is effective in preventing hepatitis.

Topics: Animals; Blotting, Western; Concanavalin A; Cytokines; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Hepatitis; Lymphocyte Activation; Mice; Mice, Transgenic; Mitogens; Natural Killer T-Cells; Reverse Transcriptase Polymerase Chain Reaction; Suppressor of Cytokine Signaling 3 Protein; Suppressor of Cytokine Signaling Proteins; T-Lymphocytes

Regulatory T cells (Tregs), which are characterized by expression of CD4, CD25, and Foxp3, play a crucial role in the control of immune responses to both self and non-self Ags. To date, there are only limited data on their role in physiological and pathological hepatic immune responses. In this study, we examined the role of hepatic Tregs in immune-mediated liver injury by using the murine Con A-induced hepatitis model. Con A treatment was associated with an increased number of Foxp3(+) Tregs in liver but not in spleen. Moreover, the expression levels of Foxp3, CTLA-4, glucocorticoid-induced TNF receptor, as well as the frequency of CD103 of Tregs were increased after Con A injection, being significantly higher in liver than in spleen. Depleting CD25(+) cells aggravated liver injury, whereas adoptively transferring CD25(+) cells or Tregs reduced liver injury in Con A-treated recipients. Con A treatment induced elevated serum levels and hepatic mononuclear mRNA expressions of TGF-beta, which were reduced by Tregs depletion. In addition, anti-TGF-beta mAbs blocked the suppressive function of Tregs from Con A-treated mice in vitro. Finally, TGF-beta receptor II dominant-negative mice, whose T cells express a dominant negative form of TGFbetaRII and therefore cannot respond to TGF-beta, had a higher mortality rate and severer liver injury than normal mice injected with the same dose of Con A. These results indicate that CD4(+)CD25(+) Tregs play an important role in limiting the liver injury in Con A-induced hepatitis via a TGF-beta-dependent mechanism.

Topics: Animals; Antigens, CD; Apoptosis; Concanavalin A; CTLA-4 Antigen; Flow Cytometry; Forkhead Transcription Factors; Hepatitis; In Situ Nick-End Labeling; Integrin alpha Chains; Mice; Mice, Inbred C57BL; Mitogens; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

Both nuclear factor kappa B (NF-kappaB) activation and inducible nitric oxide synthase (iNOS) expression increase in the liver injury, and there are NF-kappaB binding sites in the iNOS promoter. The aim of this study was to investigate the correlation between iNOS expression and NF-kappaB activation in hepatitis induced by concanavalin A (con A).. Eighty-eight male BALB/c mice were randomly divided into three groups: vehicle control group, con A group and pyrrolidine dithiocarbamate (PDTC) plus con A group. In the vehicle control group, the mice were treated with saline (0.3 mL, i.v.). In the con A group, the mice were treated with con A (20 mg/kg, i.v.). In the PDTC + con A group, the mice were pretreated with PDTC (120 mg/kg, i.p.) 30 min before administration of con A (20 mg/kg, i.v.). Blood samples were taken from the retro-orbital venous plexus at 0.5, 1, 4, 8 and 16 h after con A injection and the mice were killed immediately. The plasma alanine aminotransferase (ALT) levels were measured by the standard photometric method. Nitric oxide (NO) levels in the liver homogenate were assayed by spectroscopy. Liver tissues were sectioned and stained with hematoxylin-eosin for histological examination. Activation of NF-kappaB, degradation of inhibitor of kappa B alpha (IkappaBalpha), and expression of iNOS were measured by western blot.. In the con A group, the plasma ALT activity and NO levels in the liver increased significantly at 1 h (P < 0.05, n = 8) and reached a peak at 4 h after con A injection. The liver injury in this group was characterized by liver necrosis, cell swelling and fatty degeneration. Cytosolic IkappaBalpha decreased slightly at 30 min after con A challenge, was undetectable at 1 h and reappeared at 4 h. Correspondingly, the NF-kappaB level in the nucleus was highest at 1 h. The iNOS expression increased at 30 min after con A injection and reached a maximum at 4 h. Pretreatment with PDTC prevented these changes and attenuated the liver injury.. Con A-induced iNOS expression in the liver is dependent on the activation of NF-kappaB.

Topics: Active Transport, Cell Nucleus; Alanine Transaminase; Animals; Concanavalin A; Disease Models, Animal; Enzyme Induction; Hepatitis; I-kappa B Proteins; Liver; Male; Mice; Mice, Inbred BALB C; Necrosis; NF-KappaB Inhibitor alpha; Nitric Oxide; Nitric Oxide Synthase Type II; Pyrrolidines; Severity of Illness Index; Thiocarbamates; Time Factors; Transcription Factor RelA; Up-Regulation

Topics: Animals; Concanavalin A; Disease Models, Animal; Hepatitis; Lipids; Liver Regeneration; Mice; Mice, Inbred C57BL; T-Lymphocytes

The detrimental impact of opioid agonist on the clinical management of inflammatory diseases remains elusive. Given the anti-inflammatory properties of the mu-opioid receptor (MOR) agonists at the intestinal barrier, we hypothesised that MOR activation might also dampen acute hepatic inflammation and cell death-major determinants in the pathogenesis of liver diseases.. The expression of MOR in liver biopsy specimens and peripheral blood mononuclear cells of untreated patients with chronic hepatitis C virus infection and controls, primary hepatocytes and cell lines was determined by quantitative PCR, immunoblotting and/or immunohistochemistry. The effects of peripheral MOR agonist (d-Ala2,NMe-Phe4,Gly5-ol (DAMGO)) and/or antagonist (naloxone methiodide) were explored in two models of acute hepatitis in mice. MOR-deficient mice were used to evaluate the essential regulatory role of MOR during carbon tetrachloride (CCl(4))-induced hepatitis. The role of DAMGO in cell death was investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) analysis and quantification of lactate dehydrogenase release.. The key role of MOR in the prevention of acute hepatic inflammation and cell death in vivo and in vitro is reported. Whereas MOR gene expression increased transiently in the model of acute liver injury and TNFalpha-treated HepG2 cells, an impaired expression of MOR mRNA in human chronic hepatitis C samples was found. Furthermore, preventive administration of the selective MOR agonist DAMGO enhanced hepatoprotective-signalling pathways in vivo that were blocked by using naloxone methiodide. Consistently, genetic and pharmacological inhibition of MOR enhanced the severity associated with experimental hepatotoxin-induced hepatitis. Finally, treatment with DAMGO was shown to prevent cell death in vitro in HepG2 cells in a MOR-dependent manner and to prevent concanavalin A- and CCl(4)-induced cell death in vivo, providing a possible explanation for the anti-inflammatory role of MOR activation in the liver.. The results indicate that MOR agonists may prevent acute hepatitis and hold promising therapeutic use to maintain remission in both chronic inflammatory bowel and liver diseases.

Topics: Acute Disease; Animals; Biopsy; Carbon Tetrachloride; Cell Death; Concanavalin A; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Gene Expression; Hepatitis; Hepatitis C, Chronic; Hepatitis, Animal; Hepatocytes; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Receptors, Opioid, mu; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; Up-Regulation

Natural killer (NK) cells are innate immune cells that are enriched in the liver, but the processes underlying NK cell trafficking to the liver and cellular activation within the liver of patients with T cell-mediated liver diseases remain poorly defined. Concanavalin A (Con A) hepatitis is a murine model mimicking many aspects of human T cell-mediated liver diseases. Here we demonstrate that severe hepatitis in CCR5-deficient (KO) mice is associated with increased hepatic NK cell recruitment driven by enhanced hepatic production of CCL5 acting via CCR1 and by enhanced hepatic NK cell activation relative to that observed in wild-type mice after Con A administration. Furthermore, NK cell depletion ameliorated severe hepatitis in CCR5 KO mice but did not alter hepatitis in wild-type mice after Con A treatment. We propose that in the setting of CCR5 deficiency NK cells assume a profound effector role in Con A hepatitis via enhanced CCL5-CCR1 driven hepatic recruitment in addition to augmented cytokine-driven NK cell activation to produce interferon-gamma. These results highlight the potential profound impact of altered chemokine receptor expression on the innate immune response in the setting of T cell-mediated hepatitis.

Topics: Animals; CCR5 Receptor Antagonists; Cells, Cultured; Chemokine CCL5; Concanavalin A; Disease Models, Animal; Hepatitis; Humans; Interferon-gamma; Interleukin-4; Killer Cells, Natural; Liver; Mice; Mice, Knockout; Receptors, CCR1; Receptors, CCR5; Receptors, Chemokine; Spleen; T-Lymphocytes

The regeneration of liver tissue following transplantation is often complicated by inflammation and tissue damage induced by a number of factors, including ischemia and reperfusion injury and immune reactions to the donor tissue. The purpose of the current study is to characterize the effects of T cell-mediated hepatitis induced by concanavalin A (ConA) on the regenerative response in vivo. Liver regeneration following a partial (70%) hepatectomy (pHx) was associated with elevations in serum enzymes and the induction of key cell cycle proteins (cyclin D, cyclin E, and Stat3) and hepatocyte proliferation. The induction of T cell-mediated hepatitis 4 days before pHx increased serum enzymes 48 hours after pHx, reduced early cyclin D expression and Stat3 activation, and suppressed hepatocyte proliferation. This inhibition of proliferation was also associated with increased expression of p21, the activation of Smad2, the induction of transforming growth factor beta and interferon gamma expression, and reduced hepatic interleukin 6 production. Moreover, the ConA pretreatment increased the numbers of separate oval cell-like CD117(+) cells and hematopoietic-like Sca-1(+) cell populations 48 hours following pHx. The depletion of natural killer (NK) cells, an important component of the innate immune response, did not affect liver injury or ConA-induced impairment of hepatocyte proliferation but did increase the numbers of both CD117-positive and Sca-1-positive cell populations. Finally, splenocytes isolated from ConA-pretreated mice exerted cytotoxicity toward autologous bone marrow cells in an NK cell-dependent manner.. T cell-mediated hepatitis alters early cytokine responses, reduces hepatocellular regeneration, and induces NK cell-sensitive oval cell and hematopoietic-like cell expansion following pHx.

Topics: Animals; Cell Survival; Concanavalin A; Genes, Reporter; Hepatitis; Interferon-gamma; Interleukin-6; Killer Cells, Natural; Liver Regeneration; Male; Mice; Mice, Inbred C57BL; Mice, SCID; Mice, Transgenic; Polymerase Chain Reaction; T-Lymphocytes; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Diammonium glycyrrhizinate (DG), a traditional Chinese medicine (TCM), is extracted and purified from liquorices (Radix glycyrrhizae). The liquorices exert an important function in the treatment of hepatitis because of its anti-inflammatory effects based upon the clinical practice, but the underlying mechanism is unclear. In this study, we investigated the mechanisms of DG in protecting mice from ConA-induced hepatitis. The results showed that intraperitoneal administration of DG protected mice against ConA-induced elevation of serum ALT levels and apoptosis of hepatocytes; at the same time, the absolute amount of hepatic NKT cells and T cells was significantly decreased, indicating that DG can inhibit the recruitment of lymphocytes into the liver. In addition, the production of IL-6 and IL-10 was improved by DG pretreatment, suggesting that DG may possibly protect the liver from injury via two pathways: direct protection of hepatocytes from apoptosis through an IL-6-dependent way and indirect inhibition of T-cell-mediated inflammation through an IL-10-dependent way.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents; Concanavalin A; Glycyrrhiza uralensis; Glycyrrhizic Acid; Hepatitis; Interleukin-10; Interleukin-6; Leukocytes, Mononuclear; Liver; Male; Medicine, Chinese Traditional; Mice; Mice, Inbred C57BL; T-Lymphocytes

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

T cell immune responses play key roles in the pathogenesis of viral hepatitis, and innate immunity is known to be also activated during this process, however, the effects of innate immunity activation on T cell-mediated hepatitis remain obscure. Here we examined the effect of the activation of NK cells induced by toll-like receptor 3 (TLR3) ligand, polyinosinic-polycytidylic acid (poly I:C), on concanavalin A (Con A)-induced T cell-mediated liver injury.. Mice received nontoxic intraperitoneal poly I:C injection before Con A intravenous administration. The liver injury was examined by measuring serum transaminase and pathology, and the function of hepatic lymphocytes was detected by FACS analysis.. Poly I:C pretreatment protected against T cell-mediated hepatitis, as evidenced by decreased mortality, hepatic necrosis, serum transaminase levels and inflammatory cytokines (IL-4, IFN-gamma). The protective effect of poly I:C was diminished in NK-depleted mice, which could be partially restored by adoptive transfer of NK cells. Administration of poly I:C caused NKT and T cell apoptosis via enhancing expression of Fas protein on these cells and expression of Fas ligand on NK cells.. These findings suggest that activation of NK cells by poly I:C prevents Con A-induced T cell-hepatitis via downregulation of T/NKT cells and subsequent reduction of inflammatory cytokines.

Topics: Animals; Apoptosis; Concanavalin A; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Hepatitis; Immunity, Innate; Injections, Intraperitoneal; Interferon Inducers; Interferon-gamma; Interleukin-4; Killer Cells, Natural; Lymphocyte Activation; Male; Mice; Mice, Inbred C57BL; Poly I-C; T-Lymphocytes; Transaminases

Experimental T cell-mediated hepatitis induced by concanavalin A (ConA) results in the initiation of an inflammatory response and the production of cytokines. Adiponectin is an adipocytokine produced by adipose tissue that is involved in the reciprocal regulation of other cytokines, including tumor necrosis factor alpha (TNF-alpha). Concanavalin A administration to C57BL/6J mice reduced circulating levels of adiponectin, whereas leptin was markedly increased. Adiponectin messenger RNA expression in adipose tissue was also decreased; however, the expression of both the adiponectin receptors remained unchanged. Neutralization of TNF-alpha reduced ConA-induced liver damage, and this was associated with restored circulating levels of adiponectin. These findings indicate that inflammation-induced TNF-alpha is a critical mediator of adipose-tissue-derived adiponectin in vivo.

Topics: Adiponectin; Adipose Tissue; Animals; Concanavalin A; Hepatitis; Leptin; Mice; Mice, Inbred C57BL; Mitogens; Receptors, Adiponectin; Receptors, Cell Surface; RNA, Messenger; T-Lymphocytes; Tumor Necrosis Factor-alpha

LIGHT is an important costimulatory molecule for T cell immunity. Recent studies have further implicated its role in innate immunity and inflammatory diseases, but its cellular and molecular mechanisms remain elusive. We report here that LIGHT is upregulated and functions as a proinflammatory cytokine in 2 independent experimental hepatitis models, induced by concanavalin A and Listeria monocytogenes. Molecular mutagenesis studies suggest that soluble LIGHT protein produced by cleavage from the cell membrane plays an important role in this effect through the interaction with the lymphotoxin-beta receptor (LTbetaR) but not herpes virus entry mediator. NK1.1+ T cells contribute to the production, but not the cleavage or effector functions, of soluble LIGHT. Importantly, treatment with a mAb that specifically interferes with the LIGHT-LTbetaR interaction protects mice from lethal hepatitis. Our studies thus identify a what we believe to be a novel function of soluble LIGHT in vivo and offer a potential target for therapeutic interventions in hepatic inflammatory diseases.

Topics: Animals; Antigens, Ly; Antigens, Surface; Concanavalin A; Cytokines; Hepatitis; Inflammation; Lectins, C-Type; Listeria monocytogenes; Lymphotoxin beta Receptor; Membrane Proteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; NK Cell Lectin-Like Receptor Subfamily B; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Member 14; Receptors, Virus; Solubility; Tumor Necrosis Factor Ligand Superfamily Member 14; Tumor Necrosis Factor-alpha

Intravenous injection of concanavalin A (Con A) can cause mice to suffer from acute liver failure in a dose dependent manner and little is known about the difference between the high dose and the low dose of Con A regarding the immune response they initiate. The aim of this study was to analyze whether differential effects exist between the low dose and high dose of concanavalin A on the intrahepatic immune system and their importance in the development of liver injury.. A high dose of Con A (15 microg/g) was injected intravenously to induce murine hepatitis. A low dose of Con A (3 microg/g) was injected intravenously 12 h before the injection of the high dose of Con A (15 microg/g). Liver injury was evaluated by serum transaminase assay and H&E staining. Serum cytokine concentrations were determined by enzyme-linked immunosorbent assay (ELISA), intrahepatic cytokine and Fas mRNA levels by reverse transcriptase polymerase chain reaction. Intracellular cytokine expression and FasL expression were analyzed by flow cytometry and Fas protein expression in hepatocytes by Western-blotting. Intrahepatic apoptosis was evaluated by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL).. Low dose Con A injection induced a distinct cytokine expression profile, characterized by a preferentially elevated serum IL-6 at the early stage of stimulation, whereas high dose Con A injection provoked significant elevation of various cytokines involved in Con A-induced hepatitis. Pretreatment with a low, nonhepatoxic dose of Con A (3 microg/g) significantly decreased production of proinflammatory cytokines induced by the high dose Con A (15 microg/g). Furthermore, low dose Con A pretreatment could significantly decrease the serum levels of transaminases and liver necrosis induced by high dose of Con A. The intrahepatic Fas expression was also apparently reduced, accompanied by a decrease in hepatocyte apoptosis.. Low dose Con A stimulation induced a different cytokine profile from high dose Con A stimulation resulting in differential importance in the development of liver injury.

Topics: Animals; Apoptosis; CD3 Complex; Concanavalin A; Cytokines; Dose-Response Relationship, Immunologic; fas Receptor; Gene Expression Profiling; Hepatitis; Killer Cells, Natural; Liver; Lymphocyte Activation; Male; Mice; T-Lymphocytes

LIGHT is a member of the TNF superfamily, which is transiently expressed on the surface of activated T lymphocytes and immature dendritic cells. Its known receptors are herpesvirus entry mediator (HVEM) prominently in T lymphocytes, and lymphtoxin beta receptor (LTbetaR) in stromal cells or nonlymphoid hematopoietic cells. Previous studies have shown that overexpression of LIGHT on T cells could lead to autoimmune reaction including lymphocytes activation, inflammation, and tissue destruction. To address the role of LIGHT/HVEM signaling in autoimmune hepatitis, an experimental colitis model induced by intravenous administration of concanavalin A (ConA) was given a soluble LTbetaR-Ig fusion protein as a competitive inhibitor of LIGHT/HVEM pathway. Marked elevation of LIGHT expression was detected in isolate intrahepatic leukocytes (IHLs) of the experimental animal. Treatment with LTbetaR-Ig significantly attenuated the progression and histological manifestations of the hepatic inflammation and reduced the production of inflammatory cytokines including TNF-alpha, IFN-gamma. Moreover, LTbetaR-Ig treatment significantly down-regulated LIGHT expression, leading to reduced lymphocytes (particularly CD4+ T cells), infiltrating into the hepatic inflammation and inhibited NF-kappaB activation and expression. We postulated that blockade of LIGHT/HVEM signaling by LTbetaR-Ig may ameliorate hepatitis by down-regulating LIGHT expression, and therefore we envision that LTbetaR-Ig would prove to a promising strategy for the clinical treatment of human autoimmune hepatitis.

Topics: Animals; Concanavalin A; Hepatitis; Immunoglobulins; Interferon-gamma; Liver; Lymphotoxin beta Receptor; Male; Mice; Mice, Inbred BALB C; NF-kappa B; Signal Transduction; T-Lymphocytes; Tumor Necrosis Factor Ligand Superfamily Member 14; Tumor Necrosis Factor-alpha

Concanavalin A-induced hepatotoxicity was compared in lipodystrophic aP2-nSREBP-1c transgenic mice (LD mice) lacking adipose tissue, obese leptin-deficient ob/ob mice, and lean wild-type (WT) mice. Serum leptin and adiponectin were low in LD mice, whereas ob/ob mice had undetectable leptin, but high adiponectin. Protection from hepatotoxicity was observed in ob/ob, but not in LD mice, despite low cytokine levels and reduced T cell activation and hepatic natural killer T cells in both groups. Administration of adiponectin protected LD mice from hepatotoxicity without altering cytokine levels. In contrast, administration of leptin heightened disease susceptibility by restoring cytokine production. Neutralization of TNF alpha protected LD mice from liver damage. Increased in vivo susceptibility to the hepatotoxic effect of TNF alpha was observed in LD mice. In vitro, adiponectin protected primary hepatocytes from TNF alpha-induced death, whereas leptin had no protective effect. In conclusion, although leptin increases susceptibility to hepatotoxicity by regulating cytokine production and T cell activation, adiponectin protects hepatocytes from TNF alpha-induced death.

Topics: Adiponectin; Animals; Apoptosis; Autoimmune Diseases; CCAAT-Enhancer-Binding Proteins; Concanavalin A; Cytokines; DNA-Binding Proteins; Hepatitis; In Situ Nick-End Labeling; Intercellular Signaling Peptides and Proteins; Killer Cells, Natural; Leptin; Lipodystrophy; Lymphocyte Activation; Mice; Mice, Obese; Mice, Transgenic; Obesity; Sterol Regulatory Element Binding Protein 1; T-Lymphocytes; Transcription Factors; Tumor Necrosis Factor-alpha

Increasing evidence demonstrates that IL-6 has a protective role during liver injury. IL-6 activates intracellular pathways via the gp130 receptor. In order to identify IL-6-gp130 pathways involved in mediating liver protection, we analyzed hepatocyte-specific gp130 knockout mice in a concanavalin A-induced (Con A-induced) model of immune-mediated hepatitis. We demonstrated that IL-6-gp130-dependent pathways in hepatocytes alone are sufficient for triggering protection in Con A-induced hepatitis. gp130-STAT3 signaling in hepatocytes mediates the IL-6-triggered protective effect. This was demonstrated by analysis of IL-6-induced protection in mice selectively deficient for gp130-dependent STAT1/3 or gp130-SHP2-RAS signaling in hepatocytes. To identify IL-6-gp130-STAT1/3 dependently expressed liver-protective factors, we performed gene array analysis of hepatic gene expression in hepatocyte-specific gp130(-/-) mice as well as in gp130-STAT1/3- and gp130-SHP2-RAS-MAPK-deficient mice. The mouse IL-8 ortholog KC (also known as Gro-alpha) and serum amyloid A2 (SAA2) was identified as differentially IL-6-gp130-STAT3-regulated genes. Hepatic expression of KC and SAA2 mediate the liver-protective potential of IL-6, since treatment with recombinant KC or serum SAA2 effectively reduced liver injury during Con A-induced hepatitis. In summary, this study defines IL-6-gp130-STAT3-dependent gene expression in hepatocytes that mediates IL-6-triggered protection in immune-mediated Con A-induced hepatitis. Additionally, we identified the IL-6-gp130-STAT3-dependent proteins KC and SAA2 as new candidates for therapeutic targets in liver diseases.

Topics: Animals; Antigens, CD; Concanavalin A; Cytokine Receptor gp130; DNA-Binding Proteins; Enzyme Activation; Extracellular Signal-Regulated MAP Kinases; Gene Expression Profiling; Hepatitis; Hepatocytes; Interferon-gamma; Interleukin-6; Liver; Male; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Knockout; Serum Amyloid A Protein; Signal Transduction; STAT1 Transcription Factor; STAT3 Transcription Factor; T-Lymphocytes; Trans-Activators; Tumor Necrosis Factor-alpha

Allicin, the immunologically active component of garlic, has been found to affect oxidative stress and immune response in several experimental systems. In the present study, we examined the ability of allicin to prevent immune-mediated, concanavalin A (Con A)-induced liver damage in mice.. Mice were pretreated with allicin for 7 days before their inoculation with Con A (15 mg/kg). The serum levels of liver enzymes and liver histology were examined 24 h after Con A administration. The effect of Con A and allicin on serum levels of tumor necrosis factor-alpha (TNF-alpha) and nuclear factor-kappaB (NF-kappaB) activation in the liver were examined 2 h after Con A administration, in a separate group of rats, and the effect of allicin on Con A-induced expression of inducible nitric oxide synthase (iNOS) was determined by western blot analysis 24 h after Con A injection.. The histopathologic damage in the mouse livers, and the Con A-induced increase of aminotransferases and TNF-alpha were markedly inhibited in the mice pretreated with allicin before Con A injection (P < 0.01). NF-kappaB binding activity to the nucleus, which increased 2 h after Con A administration, was attenuated by allicin. The expression of iNOS protein which was induced following Con A administration was significantly attenuated by allicin. In vitro studies showed that allicin inhibited TNF-alpha-mediated T cell adhesion to extracellular matrix components and to endothelial cells. Allicin also inhibited TNF-alpha-mediated intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression on human vascular endothelial cells.. This study demonstrates that immune-mediated liver damage in mice can be prevented by allicin, probably because of its immunomodulatory effects on T cells and adhesion molecules and inhibition of NF-kappaB activation.

Topics: Alanine Transaminase; Animals; Antioxidants; Cell Adhesion; Concanavalin A; Disulfides; Extracellular Matrix; Garlic; Hepatitis; Intercellular Adhesion Molecule-1; Ligands; Male; Mice; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Oxidative Stress; Sulfinic Acids; T-Lymphocytes; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

The CD154-CD40 interaction is a critical costimulatory pathway modulating the cellular immune response. Moreover, fulminant hepatitis of various etiologies is characterized by a hepatic influx of CD154-expressing T cells and an upregulation of CD40 expression on Kupffer cells and hepatocytes, implicating this pathway in the pathogenesis of fulminant hepatitis. In this study, we used a murine model of fulminant hepatitis induced by concanavalin A (con A) and documented a significant influx of CD154-expressing T cells into the livers of mice treated with con A, in association with markedly increased expression of CD40 restricted mainly to hepatocytes in damaged areas of the liver. Furthermore, con A hepatitis in CD154-deficient mice was significantly attenuated compared with that in wild-type controls and was associated with a decrease in hepatic tumor necrosis factor alpha (TNF-alpha) levels and hepatocyte death. We next determined the role of the CD154-CD40 pathway in hepatocyte death in vitro. These in vitro studies demonstrated that TNF-alpha induces CD40 expression in hepatocytes and that subsequent activation of CD40 results in hepatocyte apoptosis mediated at least in part by enhanced hepatocyte expression of FasL. In conclusion, CD154 stimulation of CD40 plays a central role in hepatocyte death in fulminant hepatitis through direct and indirect pathways that may have direct therapeutic implications in humans. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).

Topics: Animals; Apoptosis; CD4-Positive T-Lymphocytes; CD40 Antigens; CD40 Ligand; Concanavalin A; Hepatitis; Hepatocytes; Immunohistochemistry; Interleukin-12; Male; Mice; Mice, Inbred C57BL; Tumor Necrosis Factor-alpha

The mechanisms that mediate the recruitment of Th1 and Th2 lymphocytes in vivo are poorly understood. We demonstrate that the mechanisms by which exogenously produced CD4(+) Th1 and Th2 cells roll and adhere in Con A-inflamed liver microcirculation differ dramatically: Th1 cells use alpha(4)beta(1)-integrin and Th2 cells use the vascular adhesion protein (VAP)-1. P-selectin plays no detectable role in Th1 or Th2 cell trafficking in liver microcirculation. Cellular recruitment in the liver sinusoids has previously been shown to be independent of many known adhesion molecules, leading to the suggestion that recruitment in these structures is mediated by physical trapping. While this may still be true for neutrophils, Th1 and Th2 cells use alpha(4)-integrin and VAP-1, respectively, to adhere within the liver sinusoids.

Topics: Amine Oxidase (Copper-Containing); Animals; Cell Adhesion; Cell Adhesion Molecules; Cell Movement; Concanavalin A; Hepatitis; Immunoglobulins; Inflammation; Integrin alpha4; Liver; Mice; Mice, Inbred BALB C; Mice, Transgenic; Mucoproteins; P-Selectin; Th1 Cells; Th2 Cells; Up-Regulation

To investigate the effects of an intradermal injection of oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs on concanavalin A (Con A)-induced hepatitis, an experimental model of immune-mediated hepatitis.. Con A was injected intravenously into Balb/c mice. Twelve hours after Con A challenge, blood and liver samples were obtained. CpG ODN was injected intradermally 48 hours before Con A challenge. The extent of liver injury was assessed by determining serum alanine transaminase (ALT) and by liver histology. Serum levels of cytokines, including interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4 and IL-5, were measured by enzyme-linked immunosorbent assay.. Co-administration of Con A and CpG ODN significantly increased serum ALT in mice compared with that in the case of administration of Con A alone (10,268 +/- 4,654 and 1,140 +/- 832 IU/1, respectively, p<0.05). In liver histology, mice treated with CpG ODN and Con A showed more extensive midzonal necrosis than did mice treated with Con A alone. These mice also showed significant increases in serum TNF-alpha and IFN-gamma and decrease in serum IL-5.. The results indicate that CpG ODNs aggravate Con A-induced hepatitis by stimulating the production of T-helper-1 (Th1) cytokines, TNF-alpha and IFN-gamma, suggesting that bacterial DNA that contains unmethylated CpG motifs may contribute to the exacerbation of immune-mediated liver injury.

Topics: Adjuvants, Immunologic; Alanine Transaminase; Animals; Concanavalin A; Female; Hepatitis; Interferon-gamma; Interleukin-5; Liver; Mice; Mice, Inbred BALB C; Oligodeoxyribonucleotides; Tumor Necrosis Factor-alpha

The role of leptin in the immune system has been well established. While adipocytes represent the major source, leptin production by lymphocytes, infiltrating at the site of inflammation, was recently demonstrated. However, the significance of this locally released leptin remains unresolved. In the present study, two models in which absence of leptin-signalling is associated with protection were employed: the model of ConA-induced hepatitis and the CD4(+)CD45Rb(high) transfer model of colitis. For the ConA model, scid mice were reconstituted with either WT or leptin-deficient (ob/ob) CD4(+) T cells. Eight weeks post transfer, ConA was injected and serum ALT, TNFalpha, leptin as well as liver mononuclear cell activation and histological signs of inflammation were evaluated. No difference between recipients of WT or ob/ob cells was observed for any of the parameters evaluated. In the second model, either WT or ob/ob CD4(+)CD45Rb(high) cells were transferred into scid mice. No histological differences were detected, although recipients of ob/ob cells showed higher weight loss compared to recipients of WT cells. Spontaneous production of IL-6 from colon cultures obtained from recipients of ob/ob cells was reduced compared to recipients of WT cells, whereas stimulation of lamina propria lymphocytes with leptin resulted in a higher IFNgamma release in recipients of ob/ob cells compared to recipients of WT cells. In conclusion, the present study provides evidence that T cell-derived leptin does not play a major role in the regulation of the inflammatory process, indicating that the adipose tissue is the critical player in the immune-modulating effects of leptin.

Topics: Animals; Apoptosis; CD4-Positive T-Lymphocytes; Colitis; Colon; Concanavalin A; Hepatitis; Intestinal Mucosa; Leptin; Leukocyte Common Antigens; Leukocytes, Mononuclear; Liver; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, SCID

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

Leukocyte cell-derived chemotaxin 2 (LECT2) was originally identified for its possible chemotactic activity against human neutrophils in vitro. It is a 16-kDa protein that is preferentially expressed in the liver. Its homologues have been widely identified in many vertebrates. Current evidence suggests that LECT2 may be a multifunctional protein like cytokines. However, the function of LECT2 in vivo remains unclear. To elucidate the role of this protein in vivo, we have generated LECT2-deficient (LECT2(-/-)) mice. We found that the proportion of NKT cells in the liver increased significantly in LECT2(-/-) mice, although those of conventional T cells, NK cells, and other cell types were comparable with those in wild-type mice. Consistent with increased hepatic NKT cell number, the production of IL-4 and IFN-gamma was augmented in LECT2(-/-) mice upon stimulation with alpha-galactosylceramide, which specifically activates Valpha14 NKT cells. In addition, NKT cell-mediated cytotoxic activity against syngeneic thymocytes increased in hepatic mononuclear cells obtained from LECT2(-/-) mice in vitro. Interestingly, the hepatic injury was exacerbated in LECT2(-/-) mice upon treatment with Con A, possibly because of the significantly higher expression of IL-4 and Fas ligand. These results suggest that LECT2 might regulate the homeostasis of NKT cells in the liver and might be involved in the pathogenesis of hepatitis.

Topics: Animals; Annexin A5; Concanavalin A; Cytotoxicity, Immunologic; Fas Ligand Protein; Flow Cytometry; Hepatitis; Intercellular Signaling Peptides and Proteins; Killer Cells, Natural; Leukocyte Count; Membrane Glycoproteins; Mice; Mice, Inbred C57BL

Leflunomide is a novel immunosuppressive and anti-inflammatory agent for the treatment of autoimmune disease. The aim of this study was to investigate whether leflunomide protects from liver injury induced by concanavalin A (Con A), a T-cell-dependent model of liver damage. BALB/c mice were injected with 25 mg/kg Con A in the presence or absence of 30 mg/kg leflunomide. Liver injury was assessed biochemically and histologically. Levels of circulating cytokines and expressions of cytokine messenger RNA (mRNA) in the liver and the spleen were determined. Treatment with leflunomide markedly reduced serum transaminase activities and the numbers of dead liver cells. Leflunomide significantly inhibited increases in plasma tumor necrosis factor alpha (TNF-alpha) and interleukin 2 concentrations, and also reduced TNF-alpha mRNA expression in the liver after administration of Con A. These findings were supported by the results in which leflunomide administration decreased the number of T lymphocytes infiltrating the liver as well as inhibiting their production of TNF-alpha. Activation of nuclear factor kappaB (NF-kappaB), which regulates TNF-alpha production, was inhibited in the liver of mice treated with leflunomide, resulting in a reduction of TNF-alpha production from lymphocytes infiltrating the liver. In conclusion, leflunomide is capable of regulating T-cell-mediated liver injury in vivo and that this event may depend on the decrease of TNF-alpha production in the liver through inhibition of NF-kappaB activation caused by leflunomide.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Caspase Inhibitors; Cells, Cultured; Concanavalin A; Cytokines; Enzyme Activation; Hepatitis; Interferon-gamma; Interleukin-2; Isoxazoles; Leflunomide; Liver; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinases; NF-kappa B; RNA, Messenger; T-Lymphocytes; Tumor Necrosis Factor-alpha

Apoptosis of T cells contributes to the immune homeostasis in inflamed organs. A prominent T-cell infiltration is usually seen in human chronic active hepatitis, being associated with liver fibrosis. In order to demonstrate T-cell apoptosis in the hepatic fibrotic tissue, we induced T-cell infiltration in the fibrotic liver of the rat by injecting concanavalin A (Con A), a T-cell mitogen. Lymphocytes increased in number with a peak at 1 day, preferentially distributing in the fibrotic tissue rather than the parenchyma. They consisted of CD4-positive and CD8-positive cells, and gave the feature of lymphoblasts. Double staining for CD3 and TUNEL demonstrated that T cells underwent apoptosis. Apoptotic cells were more frequent in the fibrotic livers than the normal livers, and were spatially associated with alpha-smooth muscle actin-positive myofibroblast-like cells that possibly derived from hepatic stellate cells (HSCs) and portal fibroblasts through activation. In vitro experiments demonstrated that lymphocyte apoptosis was more frequently induced in the co-culture of Con A-activated splenic T cells/activated HSCs compared to that induced in activated T cells/quiescent HSCs or resting T cells/activated HSCs. The present results indicate that T cells which have extravasated and infiltrated the hepatic fibrotic tissue undergo apoptosis probably through an interaction with myofibroblast-like cells, suggesting the regulatory role of the latter cells in T-cell accumulation in the fibrotic liver.

Topics: Actins; Animals; Apoptosis; CD3 Complex; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Communication; Cell Differentiation; Chemotaxis, Leukocyte; Concanavalin A; Disease Models, Animal; Fibroblasts; Hepatitis; In Situ Nick-End Labeling; Liver Cirrhosis; Male; Microscopy, Electron; Mitogens; Rats; Rats, Wistar; T-Lymphocytes

Activated cytotoxic T-cell-mediated hepatocyte apoptosis via Fas/Fas-ligand and perforin/granzyme pathways are believed to involve the model of concanavalin A (ConA)-induced hepatitis. The purpose of the present study is to investigate whether the cytokine response modifier A (crmA) gene effectively inhibits the hepatocyte apoptosis of ConA-induced hepatitis. We examined survival rates, liver pathology, immune histological changes, and cytokine profiles from mice receiving the recombinant adenovirus vectors containing cre and/or crmA genes, transferred to the liver 3 days before ConA injection, and a crmA gene nonexpression control group. Injection of ConA into mice rapidly led to massive hepatocyte apoptosis, and infiltration of leukocytes, especially CD11b(+) inflammatory cells. In contrast, liver damage was dramatically reduced in the mice that expressed the crmA gene. However, infiltration by CD4(+) cells was not affected. The survival of the mice increased significantly to 100% in the treated group versus the control group. Furthermore, we demonstrated that interleukin (IL)-18 plays an important role in ConA-induced hepatitis, and that crmA expression significantly inhibited IL-18 secretion. Our results showed that the crmA gene effectively inhibits apoptosis induced by ConA hepatitis. This indicates a potential therapeutic usage of crmA for protection from cellular damage due to hepatitis.

Topics: Adenoviridae; Animals; Apoptosis; Concanavalin A; Gene Expression; Genetic Therapy; Genetic Vectors; Hepatitis; Hepatocytes; Interferon-gamma; Interleukin-18; Male; Mice; Mice, Inbred BALB C; Serpins; T-Lymphocytes, Cytotoxic; Viral Proteins

Glycyrrhizin (GL), an aqueous extract of licorice root, is known to have various immune-modulating and biological response-modifier activities. GL is used in patients with hepatitis to reduce the activity of liver inflammation; however, the mechanism underlying the anti-inflammatory activity of GL is poorly understood. As antigen-presenting dendritic cells (DC) in the tissue play a major role in the regulation of the inflammatory mucosal milieu during tissue inflammation, we studied whether the function of liver DC was altered by GL therapy in a murine model of concanavalin-A (con A)-induced hepatitis.. Liver DC were propagated from control mice or mice with Con-A-induced hepatitis, and the effect of GL on liver DC was evaluated in vivo and in vitro.. The levels of interleukin (IL)-10 produced by liver DC were significantly lower in mice with Con-A-induced hepatitis compared with control mice. However, treatment with GL caused increased production of IL-10 in mice with Con A-induced hepatitis. The increased production of IL-10 by mice with Con A-induced hepatitis was also confirmed in vitro by culturing liver DC with GL.. This study indicates that increased production of IL-10 by liver DC due to GL administration may be involved in downregulation of the levels of liver inflammation in mice with Con A-induced hepatitis. Glycyrrhizin (GL), an aqueous extract of licorice root, is known to have various immune-modulating and biological response-modifier activities. GL is used in patients with hepatitis to reduce the activity of liver inflammation; however, the mechanism underlying the anti-inflammatory activity of GL is poorly understood. As antigen-presenting dendritic cells (DC) in the tissue play a major role in the regulation of the inflammatory mucosal milieu during tissue inflammation, we studied whether the function of liver DC was altered by GL therapy in a murine model of concanavalin-A (Con A)-induced hepatitis.

Topics: Alanine Transaminase; Animals; Anti-Inflammatory Agents, Non-Steroidal; Biomarkers; Concanavalin A; Dendritic Cells; Disease Models, Animal; Dose-Response Relationship, Drug; Genes, MHC Class II; Glycyrrhizic Acid; Hepatitis; Injections, Intraperitoneal; Interleukin-10; Interleukin-12; Liver; Male; Mice; Mice, Inbred C57BL; Phenotype; Sodium Chloride; T-Lymphocytes, Helper-Inducer; Time Factors

TH1 cytokines have been suggested to contribute to the pathogenesis of T-cell-mediated liver injury and inflammation. However, the molecular signaling pathways involved in such injury are still poorly understood. In the present study, we investigated the role of the STAT1/T-bet signaling pathway in a murine model of T-cell-mediated liver inflammation induced by the application of concanavalin A (Con A) using newly created STAT1 transgenic mice as well as STAT1- and T-bet-deficient mice. Liver injury induced by Con A was associated with an increase of both pSTAT1 and T-bet levels in the liver. Furthermore, functional studies suggested a pathogenic role for STAT1 in Con A-induced liver injury, because transgenic mice overexpressing STAT1 under the control of the CD2 promoter/enhancer construct showed elevated interferon gamma (IFN-gamma) and IRF-1 levels as well as significantly augmented liver injury following administration of Con A. Consistently, we observed that both STAT1-deficient and T-bet-deficient mice were protected from such T-cell-dependent liver injury. In conclusion, these findings suggest a key pathogenic role for the STAT1/T-bet signaling pathway for T-cell activation in the Con A model of T-cell-mediated liver pathology.

Topics: Animals; Concanavalin A; DNA-Binding Proteins; Hepatitis; Interferon Regulatory Factor-1; Interferon-gamma; Liver; Mice; Mice, Inbred C57BL; Mice, Transgenic; Phosphoproteins; Signal Transduction; STAT1 Transcription Factor; T-Box Domain Proteins; T-Lymphocytes; Trans-Activators; Transcription Factors

The activation of T-cells and macrophages and subsequent induction of cytokines are critical factors in the development of hepatitis. Up-regulation of pro-inflammatory cytokines, e.g. TNF has been shown to induce liver injury while counter regulation by anti-inflammatory cytokines, e.g. IL-10 is protective. We compared the induction of liver injury and the expression pattern of a variety of cytokines in T-cell- versus non-T-cell-dependent mouse models of liver injury. TNF, IFNgamma, IL-2, IL-4, IL-6, IL-10 and IL-12 were measured in plasma and liver tissue after either Concanavalin A (Con A), D-galactosamine/lipopolysaccharide (GalN/LPS) or high dose LPS induced liver injury. Additionally, the intra-hepatic expression of the putative pathogenicity factor high mobility group 1 protein (HMG-1) was compared in all three models.

Topics: Animals; Concanavalin A; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Galactosamine; Hepatitis; Interferon-gamma; Interleukin-10; Interleukin-12; Interleukin-2; Interleukin-4; Interleukin-6; Kinetics; Lipopolysaccharides; Liver; Mice; Mice, Inbred BALB C; Molecular Sequence Data; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Tumor Necrosis Factor-alpha; Up-Regulation

To investigate the role of FADD (Fas-associated protein with death domain) in Fas and tumor necrosis factor receptor 1 (TNFR1)-mediated hepatic injury and inflammatory response in vivo.. Fas and TNFR1 are cell surface molecules that trigger apoptosis or inflammation on engagement by a specific ligand or antibody. FADD is recruited to the cytoplasmic domain of these receptors on their activation and works as a common mediator to induce apoptosis. It is known that a blockade of FADD can inhibit apoptosis mediated by Fas or TNFR1 in vitro. However, it is not known whether the blockade can prevent organ injury and whether the inflammatory cascade is affected in vivo.. A FADD deletion mutant lacking the death effector domain was introduced into mice by transduction with an adenovirus vector, and the effect of this FADD dominant negative mutant was examined in several liver injury models.. Hepatic injury induced by anti-Fas monoclonal antibody or tumor necrosis factor (TNF)-alpha plus D-galactosamine was markedly ameliorated by the FADD dominant negative transduction, which abrogated the death rate. Further, the FADD dominant negative transduction efficiently blocked T cell- mediated concanavalin A-induced hepatitis while not affecting TNF-alpha production or TNF-alpha-induced nuclear factor-kappaB activation in the liver.. These results provide the basis for a novel therapeutic modality in which an unfavorable apoptotic process can be inhibited without affecting a favorable response for liver regeneration; this would be relevant to the clinical treatment of acute and chronic liver diseases as well as to some inflammatory disorders with hypercytokinemia, such as sepsis.

Topics: Adaptor Proteins, Signal Transducing; Adenoviridae; Animals; Antibodies, Monoclonal; Antigens, CD; Apoptosis; Carrier Proteins; Concanavalin A; Fas Ligand Protein; Fas-Associated Death Domain Protein; Galactosamine; Gene Transfer Techniques; Genetic Vectors; Hepatitis; Liver; Male; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; NF-kappa B; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Tumor Necrosis Factor-alpha

We have previously reported that cluster of differentiation (CD)4+ T cells induced autoimmune liver diseases in mice with graft-versus-host reaction (GVHR) because of major histocompatibility complex (MHC) class II disparity. To analyze the progression of the autoimmune-related mechanism in the liver, concanavalin A (Con A) was injected in mice undergoing GVHR. The aim of this study is to clarify whether Con A deteriorates murine hepatic lesions induced by GVHR, and to elucidate the participation of the cytokines of liver-infiltrating CD4+ T cells.. Mice (F1; B6.C-H-2(bm12) x B6) were intravenously injected with B6 T spleen cells. Concanavalin A (15 mg/kg) was administrated 5 days after cell transfer. We examined serum transaminase, antimitochondrial antibodies (AMA), antinuclear antibodies (ANA) and histological changes. Liver-infiltrating CD4+ T cells were sorted and their cytokine mRNA expression was examined by the use of reverse transcription-polymerase chain reaction (RT-PCR).. Graft-versus-host reaction + Con A mice revealed an elevated serum transaminase, elevated AMA and ANA titers, increased periportal cellular infiltration, piecemeal necrosis and bridging necrosis in the liver. In this group, interferon (IFN)-gamma mRNA expression was more elevated than it was in the GVHR mice. However, there was no difference in the expression of interleukin (IL)-10 mRNA between the two groups.. The results suggest that Con A deteriorates the GVHR-induced hepatic lesions, and IFN-gamma and IL-10 of CD4+ T cells might be implicated in the progression of autoimmune-related hepatic lesions. This model might offer an aspect for the investigation of progressive mechanisms in T-cell- mediated hepatobiliary injury.

Topics: Analysis of Variance; Animals; Autoantibodies; Autoimmune Diseases; CD4-Positive T-Lymphocytes; Cell Transplantation; Concanavalin A; Cytokines; Disease Models, Animal; Graft vs Host Disease; Hepatitis; Liver Function Tests; Mice; Mice, Inbred C57BL; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spleen

We analyzed the Con A affinity of serum AFP in patients with a serum AFP concentration greater than 50ng/ml by antibody affinity electrophoresis and Western blotting to distinguish hepatocellular carcinoma (HCC) from benign chronic liver diseases (CLD). Of 164 patients with HCC, 48 (29.3%) had a single band, while 116 (70.7%) had multiple bands. All but three of 65 patients with cirrhosis had a single band. All but one of 32 patients with chronic hepatitis had a single band. We concluded that multiple AFP bands are diagnosis of HCC. This method is a useful assay for distinguishing HCC from CLD.

Topics: Adult; Aged; alpha-Fetoproteins; Blotting, Western; Carcinoma, Hepatocellular; Chronic Disease; Concanavalin A; Diagnosis, Differential; Electrophoresis, Agar Gel; Female; Hepatitis; Humans; Liver Cirrhosis; Liver Neoplasms; Male; Middle Aged; Sensitivity and Specificity

A sensitive new technique for lectin-affinity immunoelectrophoresis was applied to samples from 28 infants and children in order to distinguish the origin of elevated alpha-fetoprotein (AFP) in sera. This new immunoelectrophoresis was successfully performed within 24 hours in sera with AFP as small as 910 ng/mL. With combined use of concanavalin A (Con A) and lentil agglutinin (LCH) binding tests, AFPs were classified into three subtypes: benign hepatic condition type (six patients), hepatocellular carcinoma type (nine patients) and yolk sac type (12 patients). AFP was of hepatocellular carcinoma type in all seven patients with hepatoblastoma, and of benign hepatic condition type in six of seven patients with elevated AFP due to conditions such as hepatitis, biliary atresia, and normal newborn. The question as to whether AFP produced in "hepatoblastoma" is of benign hepatic condition type or hepatocellular carcinoma type was first answered by the information in this present report. The differentiation between yolk sac and general hepatic AFPs was completed with the Con A binding test.

Topics: Adolescent; alpha-Fetoproteins; Carcinoma, Hepatocellular; Concanavalin A; Female; Hepatitis; Humans; Immunoelectrophoresis; Infant; Lectins; Liver Neoplasms; Mesonephroma; Neoplasms; Ovarian Neoplasms; Plant Lectins

Topics: Carcinoma, Hepatocellular; Chronic Disease; Concanavalin A; Diagnosis, Differential; Electrophoresis; Electrophoresis, Cellulose Acetate; gamma-Glutamyltransferase; Hepatitis; Humans; Isoenzymes; Liver Cirrhosis; Liver Neoplasms; Octoxynol; Polyethylene Glycols; Sensitivity and Specificity

T4-binding globulin (TBG), a glycoprotein with four N-glycosyl complex oligosaccharide chains, exhibits sialic acid-dependent microheterogeneity on isoelectric focusing (IEF). Increasing the sialic acid content of TBG increases its anodal IEF mobility and decreases its rate of in vivo degradation, a mechanism for the elevation of serum TBG levels in pregnancy. In this study, the structure of oligosaccharides in TBG from subjects with various conditions associated with TBG excess was determined by measuring the proportion that bound to Concanavalin-A (Con-A). Since oligosaccharides with three or more branches (antennae) attached to the trimannosyl core are excluded from binding to Con-A, the percentage of serum TBG not bound to Con-A (% peak A) represented the portion of TBG molecules with three or more antennae in all oligosaccharide chains interacting with Con-A. Peak A contained the most anodal IEF bands, while the Con-A-bound TBG (peak B) contained the cathodal bands. Serum samples from 10 normal men and 10 premenopausal women did not significantly differ in terms of TBG levels, % peak A, or IEF mobility and were combined as a single group (normal). Eight subjects with elevated serum TBG levels due to inherited TBG excess [62.0 +/- 10.1 (+/- SD) mg/L] or 2 receiving 5-fluorouracil treatment (26.2 and 31.3 mg/L) compared to 20 normal (14.7 +/- 3.3 mg/L) had % peak A values and IEF mobility similar to those in normal subjects. On the other hand, high serum TBG levels in 8 women during the third trimester of pregnancy (39.2 +/- 5.3 mg/L), 2 women taking oral contraceptives (25.7 and 27.0 mg/L), and 3 women with acute hepatitis (34.8 +/- 4.8 mg/L) were associated with significant elevations of % peak A values (5.68 +/- 1.73%, 3.31% and 2.41%, and 3.25 +/- 0.78%, respectively) compared to those in normal subjects (1.33 +/- 0.40%), as well as increased anodal mobility on IEF. Treatment of a man for 3 days with ethinyl estradiol produced similar changes. Using data from densitometry measurements of IEF bands of TBG, the degree of anodal shift was quantitated (anodal index). This index correlated with the % peak A (r = 0.92) in all study subjects. We conclude that increased sites for sialylation, resulting from the increased proportions of triantennary oligosaccharide chains, account for the increased anodal mobility of TBG in hyperestrogenemia and hepatitis. Thus, in these two conditions, a reduced TBG degradation rate resulting from oligosaccharide modificat

Topics: Adult; Binding Sites; Carbohydrate Conformation; Chromatography, Affinity; Concanavalin A; Female; Hepatitis; Humans; Male; Oligosaccharides; Structure-Activity Relationship; Thyroxine-Binding Proteins

Topics: alpha-Fetoproteins; Concanavalin A; Hepatitis; Humans; Immunoelectrophoresis; Lectins; Liver Cirrhosis; Liver Neoplasms; Phytohemagglutinins

Techniques have been studied which distinguish two variants of human alpha-fetoprotein (AFP) on the basis of characteristics of the carbohydrate moiety of this glycoprotein. AFP in serum samples from six children with tumors of yolk sac origin showed little concanavalin-A (Con A) binding. In contrast, Con A binding of AFP was almost complete in serum samples from 14 other subjects with elevated AFP, including two with liver-cell tumors, eight with neonatal cholestasis, and four normal newborn infants. Differences were confirmed by immunoelectrophoretic studies. Thus, AFP from cells of yolk sac origin can be distinguished from AFP from liver cells or from tumors of hepatic cell origin.

Topics: alpha-Fetoproteins; Bile Ducts; Carcinoma, Hepatocellular; Child; Child, Preschool; Cholestasis; Chromatography, Affinity; Concanavalin A; Female; Hepatitis; Humans; Immunoelectrophoresis, Two-Dimensional; Infant; Infant, Newborn; Jaundice, Neonatal; Liver Neoplasms; Male; Mesonephroma; Pancreatic Neoplasms; Teratoma

Con A stimulated suppressor cell function and the proportion of suppressor T cells were reduced in children with untreated chronic active hepatitis (CAH) but were normal in corticosteroid treated CAH patients, patients with severe acute hepatitis and inactive chronic liver disease. Adults with CAH also have defective suppressor function but a normal proportion of T suppressor cells. This difference may account for the observation that relapse after treatment withdrawal is less frequent in children than in adults.

Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Female; Hemolytic Plaque Technique; Hepatitis; Hepatitis, Chronic; Humans; Immunoglobulin G; Immunoglobulin M; Leukocyte Count; Liver Diseases; Male; Pokeweed Mitogens; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Helper-Inducer; T-Lymphocytes, Regulatory

Peripheral T lymphocytes from patients with chronic active hepatitis (CAH) showed a significantly decreased suppressor cell (or increased helper cell) effect on differentiation of allogenic B cells to Ig-producing cells (Ig-PC). Spontaneous helper cell activity as measured after irradiation of T cells appeared normal, while Concanavalin A (Con A)-induced suppressor cell activity was significantly reduced. Some patients of chronic persistent hepatitis (CPH) also showed mild depression of Con A-induced suppressor cell activity. Poor suppressor cell activity in CAH was much more often seen in HBsAg negative, autoantibody positive patients than in HBsAg positive autoantibody negative ones. Autologous mixed lymphocyte reaction (AMLR) was significantly decreased in patients with CAH. Also, a serum factor(s) that decreased Con A-induced suppressor cell function of healthy subjects could be demonstrated in some patients with CAH and CPH. Our results suggest that altered immune responses observed in CAH may be due to defective suppressor cell function, partly attributable to serum factor(s).

Topics: Autoantibodies; B-Lymphocytes; Concanavalin A; Female; Hepatitis; Hepatitis B Surface Antigens; Humans; Lymphocyte Activation; Lymphocyte Culture Test, Mixed; Male; T-Lymphocytes; T-Lymphocytes, Regulatory

Topics: Adult; Animals; Chronic Disease; Concanavalin A; Female; Hepatitis; Humans; Immunoglobulin Fc Fragments; Lupus Erythematosus, Systemic; Male; Middle Aged; Phytohemagglutinins; T-Lymphocytes; T-Lymphocytes, Regulatory

Suppressor T cell activity was studied serially in 11 patients with HBsAg-negative chronic active hepatitis when the disease was clinically and histologically inactive and during relapse using a short-lived suppressor cell assay. With a concentration of concanavalin A which gave a suboptimal proliferative response in normal subjects, the expected increase in thymidine incorporation was seen when the addition of the mitogen was delayed for 24 hr after the start of the lymphocyte culture period, a finding consistent with the disappearance of functional suppressor cells during the initial incubation. This effect was seen both in normal subjects and in patients with inactive disease, but was not observed at times of relapse. Further studies revealed a marked increase in lymphocyte sensitivity to concanavalin A at these times, a finding which might explain the apparent decrease in suppressor cell activity. When lower concentrations of mitogen were used in the assay, however, a significant reduction in suppressor cell activity was observed in the patients with chronic active hepatitis which was almost equal in magnitude in both the active and inactive groups, suggesting the presence of a true suppressor cell defect in this disease.

Topics: Adolescent; Adult; Chronic Disease; Concanavalin A; Dose-Response Relationship, Immunologic; Female; Hepatitis; Humans; Lymphocyte Activation; Male; Middle Aged; T-Lymphocytes, Regulatory

Topics: Chronic Disease; Concanavalin A; Hepatitis; Humans; Immune Tolerance; T-Lymphocytes, Regulatory

Suppressor cell function was studied in twenty-nine patients with chronic active hepatitis (CAH) in relation to possible aetiological causes and activity of liver disease. All fifteen patients with evidence of viral aetiology (ten HBsAg-positive CAH and five non-A, non-B CAH) showed normal suppressor cell function independently of severity of liver damage. In contrast, fourteen patients with HBsAg-negative CAH, including four cases with circulating antibodies to the hepatitis B virus, demonstrated a significant reduction in supprpessor cell activity compared to control subjects. No significant difference was found in this group between cases with and without circulating autoantibodies. In four out of five HBsAg-negative patients tested serially suppressor cell defect correlated with disease activity suggesting an abnormality in the regulation rather than a depletion of suppressor cells. These results suggest that different mechanisms are responsible for autoimmunity to the liver in virus and non-virus-related CAH.

Topics: Adolescent; Adult; Concanavalin A; Dose-Response Relationship, Drug; Female; Hepatitis; Hepatitis B; Hepatitis, Viral, Human; Humans; Lymphocyte Activation; Male; Middle Aged; T-Lymphocytes, Regulatory

Topics: Concanavalin A; Hepatitis; Humans; Liver Cirrhosis; Liver Diseases; Lymphocyte Activation

Depressed phytohaemagglutinin and concanavalin-A responsiveness was found in patients with acute viral hepatitis (VH) when a suboptimal mitogen stimulus was used. Normal responsiveness was observed with optimal mitogen stimulation. These findings were independent of extrinsic serum inhibitors. When viral hepatitis lymphocytes were preincubated before mitogen addition an enhanced responsiveness similar to the control group occurred. These in vitro findings are in favour of a primary defect in lymphoproliferation in viral hepatitis and do not suggest the presence of reversible suppressive influences such as an excess of short-lived suppressor cells or the presence of cell bound inhibitors. In chronic active hepatitis (CAH) lymphoproliferation induced by immediate mitogen stimulation was similar to control studies. However when CAH cells were preincubated before mitogen addition, enhanced responsiveness significantly greater than in controls occurred. It is suggested that suppressive influences are present in CAH and that their effect can be reversed by cellular preincubation.

Topics: Adolescent; Adult; Aged; Cells, Cultured; Child; Child, Preschool; Concanavalin A; Female; Hepatitis; Hepatitis, Viral, Human; Humans; Lymphocyte Activation; Male; Middle Aged; Phytohemagglutinins; Pokeweed Mitogens

We have studied peripheral blood mononuclear cells obtained from 24 patients with acute or chronic active hepatitis to determine if there was an abnormality in concanavalin A-induced suppressor cell activity compared to control subjects. Suppressor cells were generated by preincubation of the mononuclear cells with a mitogenic concentration of concanavalin A (6 mug/ml) for 48 hr followed by treatment with mitomycin C and alpha-methyl mannoside. Suppressor cell activity was assessed in second cultures by inhibition of concanavalin A-stimulated blast transformation of fresh allogeneic lymphocytes. Concanavalin A-stimulated suppressor activity was not elicited in mononuclear cells from the majority of patients with chronic active hepatitis in contrast to patients with acute hepatitis or acute inflammatory diseases and controls (P < 0.001). This finding was demonstrable in chronic active hepatitis patients in remission and relapse, both on and off prednisone therapy, and varied considerably during the course of the disease. The extent of liver injury was not related to the measured suppressor cell activity. These studies suggest that in chronic active hepatitis, a disease in which the host immune response may be involved, there appears to be a defect in concanavalin A-stimulated suppressor cells.

Topics: Acute Disease; Adult; Aged; Aspartate Aminotransferases; Autoimmune Diseases; Chronic Disease; Concanavalin A; Female; Hepatitis; Humans; Immunosuppression Therapy; Lymphocyte Activation; Male; Middle Aged

Topics: alpha-Fetoproteins; Antibody Formation; Chronic Disease; Concanavalin A; Hepatitis; Humans; Immunity, Cellular; In Vitro Techniques; Lymphocyte Activation; T-Lymphocytes

An alpha-feto-protein (AFP) is present in many mammals, in birds, and in sharks during development. The AFP present in different species have similar physicochemical properties and often have common antigenic determinants. Their study, both in health and disease, has provided a useful model for the understanding of other phase-specific antigens and the activation of the genes which control their synthesis. In the human fetus, the level of AFP falls with increasing maturity. The more sensitive methods of detection have disclosed that this fetal protein persists in trace amounts throughout life and its level increases in maternal blood during pregnancy. The principal sites of synthesis are the fetal liver and in some mammals, the yolk sac splanchnopleur. In humans as well as in mice and cows, it is notable that the synthesis of AFP is increased in liver cancer cells and that high levels of this protein are present in serum. Elevated values of AFP have also been detected in human subjects with undifferentiated tumours of the testis and ovary. A fall to normal levels has been noted in cases of complete remission after surgery and a return to high levels in patients who develop metastases. In some patients with hepatitis a temporary rise in the level of AFP has also been observed. In recent years, the detection of high levels of AFP in amniotic fluid has proved to be of great value for the prenatal diagnosis of neural-tube defects. Abnormal levels have also been found in the amniotic fluid or in maternal serum in cases of spontaneous abortion. Such measurements are now being assessed as a methodof monitoring abnormal pregnancy.

Topics: alpha-Fetoproteins; Amniotic Fluid; Anencephaly; Animals; Antigen-Antibody Reactions; Carcinoma, Hepatocellular; Concanavalin A; Cystic Fibrosis; Down Syndrome; Female; Fetal Proteins; Gastrointestinal Neoplasms; Gestational Age; Hepatitis; Humans; Immunologic Techniques; Infant, Newborn; Liver; Liver Neoplasms; Metabolism, Inborn Errors; Neoplasm Metastasis; Neoplasms, Experimental; Pregnancy; Spinal Dysraphism; Teratoma

Lymphocyte function in vitro was evaluated in patients with chronic active hepatitis and compared to normal controls. Circulating lymphocytes of patients were spontaneously cytotoxic to 51Cr-labeled human Chang liver cells and to suspensions of autologous liver cells obtained at the time of liver biopsy when tested at a lymphocyte target cell ratio of 200:1. Prednisone treatment of patients with chronic active hepatitis inhibited both spontaneous and concanavalin A-stimulated lymphocyte cytotoxicity to human Chang liver cells. Similarly, chronic prednisone administration substantially reduced lymphocyte cytotoxicity towards the patients' own liver cells in vitro, which correlated with a clinical, biochemical, and histological response to such therapy. Thus, patients with chronic hepatitis have circulating lymphocytes that are capable of causing destruction of their own liver cells in vitro. The beneficial effect of prednisone therapy in such patients may be related to this inhibition of lymphocyte cytotoxicity.

Topics: Cell Line; Cell Survival; Chronic Disease; Concanavalin A; Cytotoxicity Tests, Immunologic; Hepatitis; Humans; Liver; Lymphocytes; Prednisone