Fermented Lentinus edodes extract containingα-glucan ameliorates concanavalin A-induced autoimmune hepatitis in mice

Autoimmune hepatitis(AIH)is a chronic inflammatory liver disease that threatens human health worldwide.The aim of this study was to detect the protective effect of a fermented Lentinus edodes extract containingα-glucan(FLA),in a concanavalin A(Con A)-induced AIH mouse model and to determine the underlying liver-protective mechanism.The results showed that compared with the model group,the level of proinflammatory cytokines in serum of FLA pretreated mice was significantly decreased,and the degree of inflammatory cell infiltration in liver,thymus and spleen was significantly reduced.Quantitative polymerase chain reaction,immunohistochemistry,and Western blotting showed that FLA pre-treatment inhibited the Con A-induced apoptosis of hepatocytes by down-regulating the expression of BAX and up-regulating the expression of BCL-2.Further research found that FLA may improve liver injury in mice by activating NRF2 signaling pathway and inhibiting TRAF6/NF-κB signaling pathway.Thus,FLA may improve liver injury in mice by shifting gut microbial composition to reduce the release of inflammatory cytokines in the serum and prevent the necrosis of hepatocytes.Up-regulation of NRF2 signaling pathway,down-regulation of TRAF6/NF-κB signaling pathway,and an increase in the relative abundance of Lactobacillus_johnsonii and Ligilactobacillus_murinus play a protective role in liver.

Immune mechanisms of Concanavalin A model of autoimmune hepatitis

As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatments of AIH are immunosuppressant application and liver transplantation.It is considered that lack of good animal AIH models is the main reason for the shortage of a simple and efficient cure.The Concanavalin A (Con A) model is a typical and well established model for investigating T-cell and macrophage dependent liver injury in mice,which closely mimics the pathogenesis mechanisms and pathological changes of patients,and is regarded as the best experimental model for AIH research so far.In this paper we eluci-dated the pathogenic mechanisms of AIH and the evolution of relative animal models.We go on to further focus on Con A-induced liver injury from the point of immunological mechanisms and the change of cytokine levels.Finally,we manifested the clinical significance of the AIH animal models and the challenges they would meet during their future development.

Notch signaling mediated by TGF-β/Smad pathway in concanavalin A-induced liver fibrosis in rats

AIM To explore the exact interaction between Notch and transforming growth factor(TGF)-β signaling in liver fibrosis. METHODS We established a rat model of liver fibrosis induced by concanavalin A. Peripheral blood mononuclear cells(PBMCs) were isolated from the modeled rats, and cultured with γ-secretase inhibitor DAPT and TGF-β inhibitor for 24 h. The m RNA levels of Notch and TGF-β signaling were detected by quantitative real-time polymerase chain reaction. Expression of Notch and TGF-β proteins was analyzed by western blotting.RESULTS Compared to control rats, Notch and TGF-β signaling was activated in PBMCs of model rats. Administration of DAPT and TGF-β inhibitor suppressed Notch and TGF-β signal transducer in PBMCs of model rats. DAPT reduced m RNA and protein expression of TGF-β signaling, such as TGF-β1 and Smad3. TGF-β inhibitor also downregulated Notch1, Hes1 and Hes5, and m RNA and protein expression of the Notch signaling pathway.CONCLUSION Notch and TGF-β signaling play a role in liver fibrosis. TGF-β signaling upregulates Notch signaling, which promotes TGF-β signaling.

Kupffer cells contribute to concanavalin A-induced hepatic injury through a Th1 but not Th17 type response-dependent pathway in mice

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

Stem cells from human exfoliated deciduous teeth ameliorate concanavalin A-induced autoimmune hepatitis by protecting hepatocytes from apoptosis

BACKGROUND Autoimmune hepatitis is a serious autoimmune liver disease that threatens human health worldwide,which emphasizes the urgent need to identify novel treatments.Stem cells from human exfoliated deciduous teeth(SHED),which are easy to obtain in a non-invasive manner,show pronounced proliferative and immunomodulatory capacities.AIM To investigate the protective effects of SHED on concanavalin A(ConA)-induced hepatitis in mice,and to elucidate the associated regulatory mechanisms.METHODS We used a ConA-induced acute hepatitis mouse model and an in vitro co-culture system to study the protective effects of SHED on ConA-induced autoimmune hepatitis,as well as the associated underlying mechanisms.RESULTS SHED infusion could prevent aberrant histopathological liver architecture caused by ConA-induced infiltration of CD3+,CD4+,tumor necrosis-alpha+,and interferon-gamma+inflammatory cells.Alanine aminotransferase and aspartate aminotransferase were significantly elevated in hepatitis mice.SHED infusion could therefore block ConA-induced alanine aminotransferase and aspartate aminotransferase elevations.Mechanistically,ConA upregulated tumor necrosisalpha and interferon-gamma expression,which was activated by the nuclear factor-kappa B pathway to induce hepatocyte apoptosis,resulting in acute liver injury.SHED administration protected hepatocytes from ConA-induced apoptosis.CONCLUSION SHED alleviates ConA-induced acute liver injury via inhibition of hepatocyte apoptosis mediated by the nuclear factor-kappa B pathway.Our findings could provide a potential treatment strategy for hepatitis.

Effects of interleukin-18 and Anti-interleukin-18-mAb on Experimental immunological Liver Fibrosis induced by Repeatedly Administered Concanavalin A and its Mechanism

Objective To explore the prevention of IL-18 or anti-IL-18-m Ab to the immune liver fibrosis model induced by repeated injection of concanavalin A in BALB/c mice and its mechanism.Methods Total of 120 BALB/c mice were divided into four groups, control group mice(Ga) were injected weekly with normal saline, concanavalin A group was divided into Gb, Gc, Gd. All mice were injected with concanavalin A(15 mg/kg) once a week. Moreover, Gc, Gd mice were injected weekly with IL-18(7.5 mg/kg) and anti-IL-18-m Ab(10 mg/kg) 2 hours before treatment with concanavalin A, respectively. Twenty-four hours after concanavalin A challenge at 1, 5, 12 and 20 weeks, 3 mice were killed by vena orbitalis, repectively. The sera were storaged at 4℃ for detecting of up TNF-α and IFN-γ by ELISA. The liver of mice in different groups were excised and fixed in 10% formalin for HE staining and Masson staining or frozen in liquid nitrogen for immunohistochemical staining for α-SMA. After extracting of total RNA from liver tissue, MMP-2 and TIMP-1A messenger RNA were amplified by reverse transcription polymerase chain reaction(PCR). Products were electrophoresed on agrose gel containing ethidium bromide and visualized under ultraviolet light. Densitometric RT-PCR data were standardized with β-actin signals. Results After experiment, the number of dead mice of Ga, Gb, Gc and Gd were 0, 6, 15 and 3, respectively. There were significant difference on each group(P < 0.05). At the fifth week of experiment, hepatocellular necrosis in IL-18 administered group mice had become widespread throughout the lobule. Evidence of liver fibrosis was observed during this period. However, at the twelfth week of experimemt, bridging fibrosis and large fibrosis strip in the parenchyma with hepatocellular necrosis was detectable in Gb, but at twentieth week, only the small fibrosis strip had been found in anti-IL-18-mA b administered group mice by HE staining and Masson staining. The serum levels of TNF-α and IFN-γ in IL-18 administered group were higher than that in concanavalin A group and anti-IL-18 administered groups(P < 0.05). Moreover, immunohistochemical staining for α-SMA indicated that the semi-quantu scores in IL-18 administered group were more than concanavalin A group and anti-IL-18-mA b administered groups(P < 0.05). MMP-2-mR NA, TIMP-1- mR NA expression levels increased signifigantly compared with concanavalin A group and anti-IL-18-mA b administered group(P < 0.05).Conclusions The immune liver fibrosis model induced by repeated injection of concanavalin A in BALB/c mice could be worsened by IL-18 administration and block by anti-IL-18 mA b administraion.

Interleukin-22 contributes to liver regeneration in micewith concanavalin A-induced hepatitis after hepatectomy

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

Immunomodulatory effect of schisandrae oil in mouse model of autoimmune hepatitis induced by concanavalin A

Objective:To study the immunomodulatory effect of schisandra oil (SCO) in mouse model of autoimmune hepatitis induced by concanavalin A (ConA). Methods: C57BL/6 mice were divided into control group, model group and SCO group. Mice in SCO group were given SCO at 5 mg/kg by intragastric administration every day for 7 days, followed by intravenous injection of ConA at 10 mg/kg. 10 hours after ConA injection, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured by the kits, the expression of inflammatory cytokines like interferon-γ(IFN-γ), interleukin-4 (IL-4), interleukin-17 (IL-17), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β) and interleukin-6 (IL-6) in liver was detected by real-time quantitative PCR, and the T cell activation and IFN-γ expression in spleen and MLN were examined by flow cytometry. Results: Compared with control group, each indicator in model group were significantly higher. In SCO preventive treatment group, the levels of serum ALT, AST and LDH were significantly reduced (all P < 0.001), the expression levels of inflammatory cytokines in liver were downregulated, the T cell activation in spleen and MLN was inhibited (P = 0.006 and P = 0.008), the percentages of IFN-γ+ CD8+ and IFN-γ+ CD4+ T cells were decreased, and the frequencies of Th2 and Th17 cells in spleen and MLN were also decreased at the same time. Conclusion: SCO has a protective effect on immune liver injury by inhibiting the activation of T cells and reducing the expression of inflammatory cytokines, which reflects that SCO plays a role in the immunomodulation of autoimmune hepatitis, indicating that SCO is of great significance for the maintenance of autoimmune homeostasis.

Concanavalin A-induced changes in lysosomal morphology of macrophages under confocal microscope

Changes in lysosomal morphology of cultured mouse peritoneal macrophages after stimu1ation by Concanavalin A (Con A) were observed with a laser scanning confocal microscope (LSCM). A series of images were obtained including phase-contrast images, optical sectioning images, 3-dimensional reconstruction images. The changes of lysosomal fluorescence intensity and pH were measured. It was found that macrophage lysosomes were Cllstributed mainly at the periphery of the cells in resting conditions, the lysosomal area containing fluorescence probe became markedly enlarged after stimulation by Con A for 30 min, and the fluorescence intensity in the medium increased about 15 min after suggesting that Con A could induce outflow of the fluorescence probe within the macrophage lysosomes. The lysosomal pH rose from 4. 6 to 5. 7 in 7 min after Con A was added, and maintained at that level hereafter.

Ratiometric fluorescence probe for accurate detection of Concanavalin A by coupling fluorescent microsphere with boric acid functionalized carbon dots

Accurate and sensitive strategies for Concanavalin A(Con A)sensing are conducive to the better cognition of various important biological and physiological processes.Here,by designing dextran-functionalized fluorescent microspheres(DxFMs)and boric acid-modified carbon dots(BCDs)as recognition unit and built-in signal reference respectively,a ratiometric fluorescent detection platform was proposed for Con A detection with high reliability.In this protocol,the BCDs/DxFMs precipitation was formed due to the covalent interactions between cis-diol of DxFMs and boronic acid groups of BCDs,thus only fluorescence of BCDs could be detected in the supernatant.When Con A was presented,it could bind to DxFMs through its carbohydrate recognition ability and suppress the subsequent assembly between DxFMs and BCDs,leading to the simultaneous capture of DxFMs and BCDs fluorescence in the supernatant.Since the BCDs content was superfluous,their fluorescence intensities were basically constant in all cases.Based on the unchanged BCDs fluorescence signal and target-dependent DxFMs fluorescence signal in supernatant,the ratiometric detection of Con A was realized.Under optimized conditions,this ratiometric fluorescent platform displayed a linear detection range from 0.125μg/mL to 12.5μg/mL with a detection limit of 0.089μg/mL.Moreover,satisfied analytical outcomes for Con A detection in serum samples were obtained,manifesting huge application potential of this ratiometric fluorescent platform in clinical diagnosis.

Immunomodulation and liver protection of Yinchenhao decoction against concanavalin A-induced chronic liver injury in mice

OBJECTIVE：This study investigated the immunoregulatory and protective roles of Yinchenhao decoction,a compound of Chinese herbal medicine,in a mouse model of concanavalin A（Con A）-induced chronic liver injury.METHODS：Female Bal B/c mice were randomly divided into 4 groups：normal control,Con A model,Con A model treated with Yinchenhao decoction（400 mg/kg,orally）,and Con A model treated with dexamethasone（0.5 mg/kg,orally）.All treatments were given once a day for 28 d.Except of the normal control,mice received tail vein injection of Con A（10 mg/kg）on days 7,14,21,and 28,at 1 h after treatment with Yinchenhao decoction or dexamethasone or saline to induce chronic liver injury.RESULTS：Repeated Con A injection induced chronic liver injury,which was evidenced by infl ammatory cell infi ltration and necrosis,increased serum alanine aminotranferease activities,decreased albumin levels,and an imbalanced expression of immunoregulatory genes in the liver tissues including signifi cantly enhanced interferon-γ,interleukin-4,monocyte chemotactic protein-1,and cluster of differentiation 163 m RNA levels,and reduced tumor necrosis factor-αand interleukin-6 m RNA levels.Treatment with Yinchenhao decoction signifi cantly reversed the Con A-induced changes in immunoregulatory gene expression in the liver tissues,reduced serum alanine aminotranferease activity,enhanced serum albumin level,and attenuated the extent of liver infl ammation and necrosis.Furthermore,Yinchenhao decoction did not result in hepatocyte degeneration and spleen weight loss that were observed in mice received long-term treatment with dexamethasone.CONCLUSION：Yinchenhao decoction treatment protected liver against the Con A-induced chronic liver damage and improved liver function,which were associated with the modulation of gene expression related to immune/infl ammatory response.

The protective role of myeloid-derived suppressor cells in concanavalin A-induced hepatic injury

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

Protective effect of Yiguanjian decoction against DNA damage on concanavalin A-induced liver injury mice model

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

Science Letters:Proteomic analysis of differentially expressed proteins in mice with concanavalin A-induced hepatitis

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

A microarray analysis of early activated pathways in concanavalin A-induced hepatitis

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

Effect of dextran molecular weight on resonance light-scattering of quantum dots modified with dextran and concanavalin A

The reversible aggregation between dextran-conjugated CdSe quantum dots（Dex-CdSe-QDs） and concanavalin A（Con A） was explored based on the specific affinity of polysaccharide for Con A by resonance light-scattering technique.In this study,the aggregation of Dex-CdSe-QDs induced by Con A and sequential dissociation by glucose was determined over a wide range of dextran molecular mass（10-500 kDa）.The results demonstrate that the sensitivity of lectin-dextran-modified-QDs interactions increase with dextran molecular mass,and an optimum dextran molecular mass is 500 kDa.

A comparative study of changing patterns of concanavalin A-binding proteins in early stage of cholesterol gallstone

IM To elucidate the importance and the changing patterns of biliary concanavalin Abinding proteins (CPs) in the early stage of cholesterol gallstone.METHODS CPs concentrations and nucleation activities were measured by lectin affinity chromatography in biles of patients with cholesterol gallstone, pigment gallstone, gallbladder cholesterosis and nonbiliary diseases.RESULTS The concentrations of CPs were much higher in patients with cholesterol gallstone (039g/L±011g/L, n=36, P<001) or gallbladder cholesterosis (040g/L±009g/L, n=9, P<001) than in those with pigment gallstone (026g/L±012g/L, n=7) and/or nonbiliary diseases (027g/L±009g/L, n=10). Pronucleating activities were much stronger in patients with cholesterol gallstones (nucleation time ratio: 057±021, n=5, P<001 vs pigment gallstone and/or nonbiliary diseases) and gallbladder cholesterosis (nucleation time ratio: 044±023, n=5, P<001 vs pigment gallstone or nonbilliary diseases). The binding percentages of CPs to model biliary vesicles were also higher in patients with cholesterol gallstones (n=6) than those with pigment gallstones (n=6) (24%±09% vs 09%±05%, P<001).CONCLUSION Hypersecretion of CPs, especially those in vesicular phase may be the important changes in the early stage of cholesterol gallstone.

Protective effects of cyclosporine A on T-cell dependent ConA-induced liver injury in Kunming mice

INTRODUCTIONThe T-cell dependent specific liver injury in mice induced by concanavalin A(ConA) is a newly cstablished experimental liver injury model,which is considered more eligible for the study on pathophysiology of several human liver discascs,such as viral hepatitis and autommune hepatitis[1-9].T cell activation and several cytokines release had been proven to play a critical role in ConA -induced liver injury[10-19].Cyclosprine A(CsA),an effective inhibitor of activation of T lymphocytc,hes been used widely in clinical treatment,especially in autoimmune diseases and organ transplantation[20-25].In this study,we investigated the possible effect of CsA on ConA-induced liver injury in Kunning mice.

Expression of nitric oxide synthase in T-cell-dependent liver injury initiated by ConA in Kunming mice

Objective: To investigate whether nitric oxide synthase (NOS) is expressed in T-cell-dependent liver injury initiated by concanavalin A (ConA) in Kunming mice and study the possible effect of nitric oxide(NO) on liver injury models. Methods: Liver injury in Kunming mice was induced by administration of ConA through tail vein. Expression of NOS in the liver was detected by NADPH diaphorase staining method. The possible effect of NO on liver injury models was obtained by L-NAME injection to suppress synthesis of NO. Results: NOS has a strong expression in hepatocytes after ConA injection, especially in those close to the central vein, while only a weak expression was found in the epithelial cells in control group. Liver injury became more serious when NO synthesis was inhibited by L-NAME, accompanied by great malondialdehyde(MDA) increase in serum and severe intrahepatic vascular thrombosis. Conclusion: NOS markedly expressed in ConA-induced liver injury, which may subsequently promote nitric oxide synthesis. Increasement of nitric oxide has a protective effect on ConA-induced liver injury.

Elucidation of the hepatoprotective effect and mechanism of Melastoma dodecandrum Lour. based on network pharmacology and experimental validation

Objective:To systematically explore the effect and mechanism of melastomatis dodecandri herba(Melastoma dodecandrum Lour.)in the treatment of hepatitis based on network pharmacology.Method:We evaluated the hepatoprotective effects of M.dodecandrum in concanavalin A(Con A)-induced hepatitis in mice by assessing survival rate,histological analysis,serum transaminases,and related cytokines.Then the mechanism of action was predicted by a network pharmacology-based strategy.Based on the results,we measured the hepatic expression of related genes at mRNA level and proteins related to the phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt)and nuclear factorkappa B(NF-кB)pathways.Results:Our study results clearly demonstrated that M.dodecandrum pretreatment significantly alleviated liver injury.This was demonstrated by an increase in survival rate,decreased severity of liver damage,and reduced serum transaminase levels compared with those in the Con A group.Moreover,M.dodecandrum significantly reduced the serum levels of tumor necrosis factor-a,interleukin-6,and interferon-g and increased the liver levels of superoxide dismutase,which indicated that M.dodecandrum exhibits anti-inflammatory and antioxidant activities.On the basis of network pharmacology,50 nodes were selected as major hubs based on their topological importance.Pathway enrichment analyses indicated that the putative targets of M.dodecandrum mostly participate in various pathways associated with the anti-inflammation response,which implies the underlying mechanism by which M.dodecandrum acts on hepatitis.Real-time fluorescent quantitative PCR analysis showed that M.dodecandrum downregulates the mRNA expression of interleukin-6,Toll-like receptor 7,interleukin-1 receptor-associated kinase-4,NF-кB and tumor necrosis factor-a in liver tissues.Western blotting showed that M.dodecandrum pretreatment protected against inflammation through activating the PI3K-Akt pathway by upregulating phosphorylated Akt(p-Akt)expression and suppressing NF-кB activation by inhibiting the phosphorylation of IKK,IkBa,and p65.Conclusion:The present work demonstrated the hepatoprotective effects of M.dodecandrum by regulating the PI3K/Akt and NF-кB pathways in Con A-induced mice,which provide insights into the treatment of hepatitis using M.dodecandrum.