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Hyperadamans A-G (1-7), seven new adamantane type polycyclic polyprenylated acylphloroglucinols (PPAPs), were isolated from Hypericum wilsonii N. Robson. Structurally, 1-4 were the first adamantanes bearing an unusual 2,7-dioxabicyclo-[2.2.1]-heptane fragment, and compound 5 was the first adamantane with a rare 1,6-dioxaspiro[4.4]nonane section. Importantly, 1-7 exhibited significant immunosuppressive activity on Con A-induced T-lymphocyte proliferation in vitro, with IC 50 values ranging from 3.97 ± 0.10 to 18.12 ± 1.07 μM. Pretreatment with 1 in Con A-challenged autoimmune hepatitis mice could dramatically ameliorate the levels of hepatic injury indexes (ALT and AST) and reduce the product of proinflammatory cytokines (COX-2, IL-6, IL-1β, IL-18, IL-23A and TNF-α). Furthermore, the protective effect of 1 on the Con A-induced liver injury was corroborated by the histological analysis and the immunohistochemistry., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The incidence of autoimmune hepatitis (AIH) has increased significantly worldwide. The present study aims to explore the protective effect of L-lysine supplementation against AIH and to investigate its potential underlying mechanisms. A chronic experimental AIH mouse model was established by repeated tail vein injection of human cytochrome P450 2D6 (CYP2D6) plasmid. Starting from day 14 of the modeling, mice in the CYP2D6-AIH +L-lysine group were given 200 µl of purified water containing 10 mg/kg L-lysine by gavage until day27, once a day, and mice in the healthy control group and model group were given an equal volume of purified water by gavage. Our results showed that L-lysine supplementation partially reversed the liver injury mediated by CYP2D6 overexpression. These effects were consistent with the restraining impacts of L-lysine supplementation on decreasing pro-inflammatory cytokines expression level and CD4 + and CD8 + T lymphocytes infiltration, as well as curbing hepatic oxidative stress. Furthermore, L-lysine supplement relieved liver fibrosis in the context of AIH. In conclusion, L-lysine supplementation attenuates CYP2D6-induced immune liver injury in mice, which may serve as a novel nutrition support approach for AIH.

Background: Traditional Chinese medicine has used the drug Pien Tze Huang (PTH), a classic prescription, to treat autoimmune hepatitis (AIH). However, the precise mode of action is still unknown., Aim: To investigate the mechanism of PTH in an AIH mouse model by determining the changes in gut microbiota structure and memory regulatory T (mTreg) cells functional levels., Methods: Following induction of the AIH mouse model induced by Concanavalin A (Con A), prophylactic administration of PTH was given for 10 d. The levels of mTreg cells were measured by flow cytometry, and intestinal microbiota was analyzed by 16S rRNA analysis, while western blotting was used to identify activation of the toll-like receptor (TLR)2, TLR4/nuclear factor-κB (NF-κB), and CXCL16/CXCR6 signaling pathways., Results: In the liver of mice with AIH, PTH relieved the pathological damage and reduced the numbers of T helper type 17 cells and interferon-γ, tumor necrosis factor-alpha, interleukin (IL)-1β, IL-2, IL-6, and IL-21 expression. Simultaneously, PTH stimulated the abundance of helpful bacteria, promoted activation of the TLR2 signal, which may enhance Treg/mTreg cells quantity to produce IL-10, and suppressed activation of the TLR4/NF-κB and CXCL16/CXCR6 signaling pathways., Conclusion: PTH regulates intestinal microbiota balance and restores mTreg cells to alleviate experimental AIH, which is closely related to the TLR/CXCL16/CXCR6/NF-κB signaling pathway., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

Ethnopharmacological Relevance: Tripterygium wilfordii tablets (TWT) is widely used to treat autoimmune diseases such as rheumatoid arthritis. Celastrol, one main active ingredient in TWT, has been shown to produce a variety of beneficial effects, including anti-inflammatory, anti-obesity, anti-cancer, and immunomodulatory. However, whether TWT could protect against Concanavalin A (Con A)-induced hepatitis remains unclear., The Aim of the Study: This study aims to investigate the protective effect of TWT against Con A-induced hepatitis and elucidate the underlying mechanism., Materials and Methods: Metabolomic analysis, pathological analysis, biochemical analysis, qPCR and Western blot analysis and the Pxr-null mice were used in this study., Results: The results indicated that TWT and its active ingredient celastrol could protect against Con A-induced acute hepatitis. Plasma metabolomics analysis revealed that metabolic perturbations related to bile acid and fatty acid metabolism induced by Con A were reversed by celastrol. The level of itaconate in the liver was increased by celastrol and speculated as an active endogenous compound mediating the protective effect of celastrol. Administration of 4-octanyl itaconate (4-OI) as a cell-permeable itaconate mimicker was found to attenuate Con A-induced liver injury through activation of the pregnane X receptor (PXR) and enhancement of the transcription factor EB (TFEB)-mediated autophagy., Conclusions: Celastrol increased itaconate and 4-OI promoted activation of TFEB-mediated lysosomal autophagy to protect against Con A-induced liver injury in a PXR-dependent manner. Our study reported a protective effect of celastrol against Con A-induced AIH via an increased production of itaconate and upregulation of TFEB. The results highlighted that PXR and TFEB-mediated lysosomal autophagic pathway may offer promising therapeutic target for the treatment of autoimmune hepatitis., Competing Interests: Declaration of competing interest The authors have declared no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background and Aim: Celastrol is extracted from Tripterygium wilfordii Hook F. It has been reported to have protective effects against various liver diseases and immune regulation of autoimmune diseases. However, little is known about whether celastrol protects against immune-mediated hepatitis. This study aimed to investigate the effect of celastrol on liver injury induced by concanavalin A (ConA) and the potential mechanisms., Methods: Intravenous administration of ConA was applied to induce acute liver injury in mice with or without pretreatment of celastrol. The effects of celastrol on ConA-induced liver injury were further demonstrated by biochemical and histopathological assessments, immunoblotting, and flow cytometry analysis., Results: Both biochemical and histopathological observations showed that pretreatment of celastrol significantly ameliorated liver injury induced by ConA. Moreover, the hepatocyte apoptosis and inflammatory responses induced by ConA were also improved in celastrol-pretreated mice. Further studies revealed that these improvements were characterized as the celastrol-mediated suppression of total interleukin (IL)-17 from liver mononuclear cells in ConA-treated mice. Flow cytometry analysis suggested that celastrol specifically decreased IL-17 production by CD4 + T cells but not by CD8 + T cells. Fundamentally, pretreatment with celastrol inhibited both the IL-6 produced by F4/80 + macrophages and the IL-6 receptor on Th17 cells in the liver, which further led to the downregulated activation of STAT3, thus accounting for blocked Th17 signaling., Conclusions: Celastrol may exhibit immune regulatory effects by regulating IL-6/STAT3-IL-17 signaling in ConA-induced hepatitis, which suggested new potentials for celastrol to be applied in treating immune-mediated liver diseases., (© 2023 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Autoimmune hepatitis (AIH) is a typical T cell-mediated chronic liver disease with a higher incidence in females. However, the molecular mechanism for the female predisposition is poorly understood. Estrogen sulfotransferase (Est) is a conjugating enzyme best known for its function in sulfonating and deactivating estrogens. The goal of this study is to investigate whether and how Est plays a role in the higher incidence of AIH in females. Concanavalin A (ConA) was used to induce T cell-mediated hepatitis in female mice. We first showed that Est was highly induced in the liver of ConA-treated mice. Systemic or hepatocyte-specific ablation of Est, or pharmacological inhibition of Est, protected female mice from ConA-induced hepatitis regardless of ovariectomy, suggesting the effect of Est inhibition was estrogen independent. In contrast, we found that hepatocyte-specific transgenic reconstitution of Est in the whole-body Est knockout (EstKO) mice abolished the protective phenotype. Upon the ConA challenge, EstKO mice exhibited a more robust inflammatory response with elevated production of proinflammatory cytokines and changed liver infiltration of immune cells. Mechanistically, we determined that ablation of Est led to the hepatic induction of lipocalin 2 (Lcn2), whereas ablation of Lcn2 abolished the protective phenotype of EstKO females. Our findings demonstrate that hepatocyte Est is required for the sensitivity of female mice to ConA-induced and T cell-mediated hepatitis in an estrogen-independent manner. Est ablation may have protected female mice from ConA-induced hepatitis by upregulating Lcn2. Pharmacological inhibition of Est might be a potential strategy for the treatment of AIH., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Garcinia mangostana L. (Clusiaceae), a popular tropical fruit for its juiciness and sweetness, is an opulent fountain of prenylated and oxygenated xanthones with a vast array of bio-activities. Garcinone E (GE), a xanthone derivative reported from G. mangostana, possesses cytotoxic and aromatase inhibitory activities. The present research endeavors to investigate the hepato-protection efficaciousness of GE on concanavalin-A (Con-A)-instigated hepatitis. Results showed that GE pretreating noticeably diminishes both the serum indices (transaminases, ALP, LDH, and γ-GT) and histopathological lesions of the liver. It counteracted neutrophil and CD4+ infiltration into the liver. GE furthered the Nrf2 genetic expression and its antioxidants' cascade, which resulted in amelioration of Con-A-caused oxidative stress (OS), lipid per-oxidative markers (4-HNE, MDA, PC) reduction, and intensified antioxidants (TAC, SOD, GSH) in the hepatic tissue. Additionally, GE prohibited NF-ĸB (nuclear factor kappa-B) activation and lessened the genetics and levels of downstream cytokines (IL1β and IL6). Moreover, the TNF-α/JNK axis was repressed in GE-treated mice, which was accompanied by attenuation of Con-A-induced apoptosis. These findings demonstrated the protective potential of GE in Con-A-induced hepatitis which may be associated with Nrf2/HO-1 signaling activation and OS suppression, as well as modulation of the NF-κB and TNF-α/JNK/apoptosis signaling pathway. These results suggest the potential use of GE as a novel hepato-protective agent against autoimmune hepatitis.

The clinical picture of autoimmune hepatitis (AIH) varies markedly between patients, potentially due to genetic modifiers. The aim of this study was to evaluate genetic variants previously associated with fatty liver as potential modulators of the AIH phenotype. The study cohort comprised 313 non-transplanted adults with AIH. In all patients, the MARC1 (rs2642438), HSD17B13 (rs72613567), PNPLA3 (rs738409), TM6SF2 (rs58542926), and MBOAT7 (rs641738) variants were genotyped using TaqMan assays. Mitochondrial damage markers in serum were analyzed in relation to the MARC1 variant. Carriers of the protective MARC1 allele had lower ALT and AST (both P < 0.05). In patients treated for AIH for ≥ 6 months, MARC1 correlated with reduced AST, ALP, GGT (all P ≤ 0.01), and lower APRI (P = 0.02). Patients carrying the protective MARC1 genotype had higher total antioxidant activity (P < 0.01) and catalase levels (P = 0.02) in serum. The PNPLA3 risk variant was associated with higher MELD (P = 0.02) in treated patients, whereas MBOAT7 increased the odds for liver cancer (OR = 3.71). None of the variants modulated the risk of death or transplantation. In conclusion, the MARC1 polymorphism has protective effects in AIH. Genotyping of MARC1, PNPLA3, and MBOAT7 polymorphisms might help to stratify patients with AIH., (© 2021. The Author(s).)

Myeloid-derived suppressor cells (MDSCs) emerge as a promising candidate for the immunotherapy of autoimmune hepatitis (AIH). However, targets for modulating MDSC in AIH are still being searched. Liver X receptors (LXRs) are important nuclear receptors linking lipid metabolism and immune responses. Despite the extensive studies of LXR in myeloid compartment, its role in MDSCs is currently less understood. Herein, expression of LXRα was found to be upregulated in AIH patients and colocalized with hepatic MDSCs. In ConA-induced hepatitis, deletion of LXRα led to increased expansion of MDSCs in the liver and alleviated the hepatic injury. MDSCs in LXRα -/- mice exhibited enhanced proliferation and survival comparing with WT mice. T-cell proliferation assay and adoptive cell transfer experiment validated the potent immunoregulatory role of MDSCs in vitro and in vivo . Mechanistically, MDSCs from LXRα -/- mice possessed significantly lower expression of interferon regulatory factor 8 (IRF-8), a key negative regulator of MDSC differentiation. Transcriptional activation of IRF-8 by LXRα was further demonstrated., Conclusion: We reported that abrogation of LXRα facilitated the expansion of MDSCs via downregulating IRF-8, and thereby ameliorated hepatic immune injury profoundly. Our work highlights the therapeutic potential of targeting LXRα in AIH., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Li, Lian, Li, Qian, Zhang, Liu, Tang and Ma.)

The gut-liver axis has been increasingly recognized as a major autoimmunity modulator. However, the implications of intestinal barrier in the pathogenesis of autoimmune hepatitis (AIH) remain elusive. Here, we investigated the functional role of gut barrier and intestinal microbiota for hepatic innate immune response in AIH patients and murine models. In this study, we found that AIH patients displayed increased intestinal permeability and pronounced RIP3 activation of liver macrophages. In mice models, intestinal barrier dysfunction increased intestinal bacterial translocation, thus amplifying the hepatic RIP3-mediated innate immune response. Furthermore, GSK872 dampened RIP3 activation and ameliorated the activation and accumulation of liver macrophages in vitro and in vivo experiments. Strikingly, broad-spectrum antibiotic ablation significantly alleviated RIP3 activation and liver injury, highlighting the causal role of intestinal microbiota for disease progression. Our results provided a potentially novel mechanism of immune tolerance breakage in the liver via the gut-liver axis. In addition, we also explored the therapeutic and research potentials of regulating the intestinal microbiota for the therapy of AIH., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Liu, Zhong, Zheng, Li, Guo, Zhang, Ran, Zhao, Zhou and Wang.)

Rosmarinic acid (RA) is extensively utilized in herbal medicine in China. The AMP-activated protein kinase (AMPK) signaling can be activated by RA and inhibited by the synthetic, reversible AMP-competitive inhibitor, Compound C (CC). The objective of this study was to investigate the role of AMPK signaling involving the protective effects of RA on concanavalin A (Con A)-induced autoimmune hepatitis (AIH) in mice. BALB/c mice were treated with RA, with or without CC, followed by the pretreatment with Con A. Analysis of serum aminotransferases and cytokines were conducted and liver tissue histology was performed to evaluate hepatic injury. Cytokine levels in serum and hepatic tissue were respectively measured by enzyme-linked immunoassay (ELISA) and used quantitative (q)PCR. Levels of phosphorylated acetyl CoA carboxylase in the liver, representing AMPK activation, were detected by Western blotting. Compared with the Con A group, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in RA group (100 and 150 mg/kg/d) were significantly reduced. RA also reduced hepatocyte swelling, cell death, and infiltration of leukocytes in the liver of Con A-treated mice. Serum levels of cytokines, such as interferon-γ (IFN-γ), interleukin-2 (IL-2) and interleukin-1β (IL-1β), were reduced by RA pretreatment, while the levels of serum interleukin-10 (IL-10), an anti-inflammatory cytokine, was elevated. These protective effects were reversed by treatment with CC. RA treatment reduced the hepatic damage via the activation of AMPK in the mice of Con A-induced. So RA acts as a potential part in the therapy of autoimmune hepatitis.

Background: Autoimmune hepatitis (AIH) is an immune-mediated inflammation of the liver characterized by disorganized hepatic parenchyma and inflammatory cell infiltration. Although the increased incidence of AIH, the development of novel therapeutic strategies are impeded by the poor understanding of the accompanied detailed immunopathogenic changes. CD4+ T cells are key mediators of inflammatory cell infiltration in initial phases of liver injuries like AIH. The distribution of CD4+ cells and the histopathological changes accompanying Con A-induced AIH were investigated together with the postulated protective effect of Amygdalin (Amg.)., Materials and Methods: 30 adult male mice were divided into three groups; control, AIH and AIH-Amg. groups. AIH was induced by a single intravenous injection of Concanavalin A (Con A) (15 mg/kg). The AIH-Amg. group received Amg. 5 mg/kg intraperitoneally once a week for three weeks. Blood samples were examined for ALT and AST. MDA, SOD, and GSH were determined in hepatic homogenates. Liver section stained with hematoxylin and eosin, Masson trichrome and CD4+ immune stain were examined by light and electron microscopy., Results: AIH group showed a significant increase in levels of ALT, AST and MDA and a significant decline in SOD and GSH compared to the controls. The liver tissue showed distorted hepatic architecture with intercellular hemorrhage, necrosis, and inflammatory cell infiltration. The area percent of CD4+ immune staining was significantly increased. Electron microscopic examination showed massive cellular degenerative changes. Amg. pretreatment in AIH-Amg. group significantly reversed these changes., Conclusion: AIH induced CD4+ cells infiltration in the liver with subsequent liver tissue damage. Amg. pretreatment inhibited CD4+ cell infiltration and protected the liver tissue. This finding suggests that Amg. could be a therapeutic agent in the management of AIH., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease of an unknown etiology, glucocorticoid therapy is currently recognized as an effective treatment for AIH, but conventional application and patient compliance are both hindered by its side effects. The exploration of the AIH pathogenesis and the searching for the new candidate drugs that exert potential activity and low toxicity are urgently needed. Pomegranate peel extract (PoPx) is a natural extract of Punica granatum and has been reported to have anti-inflammatory and antioxidative properties. The present study aimed to clarify the effect of PoPx on the concanavalin A (ConA)-induced autoimmune hepatitis in a mouse model that is well established at 12h after tail vein injection with a dose of 20 mg/kg of ConA. C57BL/6 female mice were pretreated with PoPx (250 mg/kg, once daily for 3 days) followed by a ConA challenge. Pretreatment with PoPx significantly alleviated ConA-induced liver injury by down-regulating the levels of plasma alanine transaminase (ALT), aspartate transaminase (AST) and cytokine, including TNF-α, interferon (IFN) -γ and interleukin (IL)-6. Moreover, liver hematoxylin and eosin (H&E) staining displayed a lighter inflammatory infiltration around the portal area in the PoPx-pretreated mice. In addition, the flow cytometry (FCM) data showed that the immune response in the liver was died down in the PoPx-pretreated condition. Specially, pretreatment with PoPx reduced the infiltration of activated CD4 + and CD8 + T cells in the liver. Taken together, these findings contributed to a better understanding of the actions of PoPx against acute AIH and indicated that PoPx might be a potential compound in treating T cell-mediated autoimmune liver injury., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

A 61-year-old woman was admitted to our hospital because of muscle paralysis and was found to have severe hypokalemia. A gallium-67 scintigram revealed a positive accumulation in the bilateral salivary glands, and a labial minor salivary gland biopsy demonstrated a massive lymphocyte infiltrate around the salivary ducts. She was diagnosed with Sjögren's syndrome (SS) associated with renal tubular acidosis. Renal biopsy revealed tubulointerstitial nephritis with a mild focal infiltration of lymphocytes and plasma cells. These pathological features were compatible with SS with renal involvement. Acidosis and hypokalemia were corrected with sodium bicarbonate and potassium chloride, which relieved the patient's symptoms. Although steroid therapy has been reported to be effective in SS-associated tubulointerstitial nephritis, the patient's serum potassium level could be controlled without administering steroids during the first admission. Five years later, she was admitted again because of severe liver dysfunction attributed to autoimmune hepatitis. Oral administration of prednisolone resulted in the normalization of her transaminase levels, and the control of her serum potassium level became easier. It has been reported that patients with SS with salivary gland involvement tend to have hepatic complications, and those with hepatic complications tend to have renal involvement. Physicians should be aware of hepatic involvement, even if there is no liver dysfunction at the initial diagnosis of SS with salivary gland and renal involvement. It remains uncertain whether the administration of a low dose of steroids before the onset of autoimmune hepatitis might have prevented the development of liver dysfunction in our patient.

Aims: Propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide possesses anti-inflammatory effects. Here, we investigated the effect of PSS on concanavalin A (Con A)-induced liver injury in mice and examined the underlying mechanisms., Main Methods: Balb/C mice were injected intravenously with Con A (25mg/kg) to generate a model of acute liver injury. PSS (25 or 50mg/kg) was injected intraperitoneally 1h before the Con A administration. The levels of serum liver enzymes, inflammatory cytokines, and other marker proteins were determined, and liver injury was assessed histopathologically 2, 8, and 24h after Con A injection., Key Findings: Pretreatment with PSS reduced the levels of serum liver enzymes, inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and attenuated histopathological damage in Con A-induced liver injury in mice. The effects of Con A were mediated by apoptosis and autophagy, as indicated by changes in protein and gene expression of related factors after Con A injection. PSS activated the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway and showed a protective function against apoptosis and autophagy., Significance: PSS ameliorated Con A-induced liver injury by downregulating inflammatory cytokines including TNF-α and IL-1β and regulating apoptosis and autophagy via the PI3K/Akt pathway., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The anti-malarial drug artesunate (ARS) has been shown to possess anti-inflammatory activity. Its effect on autoimmune hepatitis remains unclear. Concanavalin A (Con A)-induced hepatitis was used in this study to reveal the potential action of ARS and the related mechanism. Mice were pretreated with ARS followed by Con A challenge. Con A caused obvious hepatic injury with higher levels of liver enzymes, elevated pro-inflammatory cytokines and activation of nuclear factor-κB (NF-κB) and mitogen activated protein kinase (MAPK) signaling pathways. However, ARS pretreatment notably inhibited Con A-induced liver injury with remarkable reduction of liver enzymes, and dramatically suppressed the expression of inflammatory cytokines including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-17, and increased anti-inflammatory cytokines IL-10. In line with cytokines, the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinases (p38), nuclear factor-κBα (IκBα) and NF-κB p65 was also significantly inhibited by ARS pretreatment. As a contrast, the specific inhibitor of NF-κB pyrrolidine dithiocarbamate (PDTC) achieved similar repressive effects as ARS on phosphorylation of p65 and IκBα, and serum levels of aminotransferases. Taken together, these data highlight that ARS has facilitating to make a better understanding of ARS against acute autoimmune hepatitis, and indicating a promising therapy candidate for autoimmune hepatitis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Recurrent autoimmune hepatitis (AIH) and de novo AIH are 2 important causes of late graft failure after liver transplantation (LT). Recurrent AIH occurs in patients who undergo LT for AIH. De novo AIH occurs in patients who are transplanted for etiologies other than AIH. Although typically treated with standard treatment for AIH, including corticosteroids and azathioprine, both recurrent and de novo AIH may progress to end-stage liver disease requiring retransplantation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Hedyotis hedyotidea has been used in traditional Chinese medicine for the treatment of autoimmune diseases. However, the mechanisms underlying for the effect remain unknown. We previously showed that, among 11 compounds extracted from H hedyotidea, betulin produced the strongest suppressive effect on T cell activation. Here, we examined the hepatoprotective effects of betulin against acute autoimmune hepatitis in mice and the mechanisms underlying the effects. Freshly isolated mouse splenocytes were stimulated with concanavalin A (Con A, 5 μg/mL) in the presence of betulin, the cell proliferation was assessed with CSFE-dilution assay. Mice were injected with betulin (10, 20 mg·kg -1 ·d -1 , ip) for 3 d. One hour after the last injection, the mice were injected with Con A (15 mg/kg, iv) to induce acute hepatitis. Blood samples and liver tissues were harvested at 10 h after Con A injection, and serum transaminase levels and liver histopathology were detected; serum levels of proinflammatory cytokines, hepatic T lymphocyte ratios, and functional statuses of conventional T and NKT cells were also analyzed. Betulin (16 and 32 μmol/L) dose-dependently suppressed the proliferation of Con A-stimulated mouse splenocytes in vitro. In Con A-challenged mice, preinjection with betulin (20 mg·kg -1 ·d -1 ) significantly decreased the levels of proinflammatory cytokines IFN-γ, TNF-α and IL-6, and ameliorated liver injury. Furthermore, pretreatment with betulin (20 mg·kg -1 ·d -1 ) significantly inhibited the Con A-induced activation of NKT and conventional T cells, and decreased production of proinflammatory cytokines IFN-γ, TNF-α and IL-6 in these two cell populations. Betulin has immunomodulatory effect on overly activated conventional T and NKT cells and exerts hepatoprotective action in mouse autoimmune hepatitis. The findings provide evidence for the use of H hedyotidea and its constituent betulin in the treatment of autoimmune diseases.

Objectives: This study aimed to evaluate the potential protective effects of pirfenidone (PFD) against concanavalin A (Con A)-induced hepatitis in mice., Methods: Autoimmune model of hepatitis was established using single intravenous injection of Con A. Mice were randomly assigned into four groups as follows: control group; Con A group; and two groups, receiving PFD in two dose levels (200, 300 mg/kg) for 5 days before Con A administration. Extent of hepatitis was studied using biochemical, histopathological and immunohistochemical estimations., Key Findings: Hepatitis was clearly evident through extensive hepatocellular lesions and elevated levels of serum transaminases, alkaline phosphatase and lactate dehydrogenase. Con A induced an imbalance between oxidant and antioxidant status in the hepatic tissue. Furthermore, Con A significantly elevated hepatic nuclear factor kappa B (NF-κB) expression and inflammatory cytokines levels (tumour necrosis factor-alpha, interleukin-6 and nitric oxide). PFD pretreatment potently ameliorated all these pathological changes., Conclusions: Pirfenidone hepatoprotective activity may be mediated through its antioxidant ability that suppresses NF-κB activation signalling pathways suggesting that PFD may be a new candidate for treatment of acute hepatitis., (© 2016 Royal Pharmaceutical Society.)

The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct innate and adaptive immune responses. Myeloid-derived suppressive cells (MDSCs) are a heterogeneous cell population that plays a crucial regulatory effect in immune-related diseases. However, whether mTOR signaling affects the functions of MDSCs remains largely unexplored. Here, we show that mTOR signaling is a pivotal, negative determinant of MDSC function in immune-mediated hepatic injury (IMH) diseases. In the context of IMH, the blocking of mTOR with rapamycin or mTOR-deficient CD11b + Gr1 + MDSCs mediates the protection against IMH; mTOR with rapamycin and mTOR-deficient CD11b + Gr1 + MDSCs are suppressive immune modulators that result in less IFN-γ-producing T H 1 cells and more Foxp3 + T regs Mechanistically, mTOR activity down-regulation in MDSCs induced iNOS expressions and NO productions. Pharmacologic inhibitions of iNOS completely eliminate MDSC-suppressive function and lose their inducible effects on T cell differentiation. Importantly, HIF1α-dependent glycolytic activity is responsible for mTOR-deficient, increased MDSC functional changes in IMH inflammation. Thus, these data demonstrate that mTOR acts as a fundamental "rheostat" in MDSCs to link immunologic signals to glycolytic pathways and functional fitness and highlights a central role of metabolic programming of MDSC-suppressive activity in protecting against immune hepatic injuries., (© Society for Leukocyte Biology.)

This review presents the author's personal perspective and contributions to the first steps, the development, the current status, and the remaining issues of pediatric liver transplantation (LT). Innumerable children around the world who have undergone LT have reached adulthood. The techniques have reached maturity. As shown by my own group's experience, grafts donated by living donors might provide the best short-term and longterm results. Debate persists about the optimal immunosuppression (IS), although the place of tacrolimus remains unchallenged. Tolerance induction protocols aiming to induce microchimerism have been tried in clinical transplantation without convincing results. Withdrawal of maintenance IS is possible in some children who underwent liver transplantation who have excellent clinical status and normal liver function tests but is not without risk of rejection and subsequent worsening of histology. The current trend favored by the Brussels' group is to minimize IS as soon after transplant as possible, aiming to obtain a state of "prope" or "almost" tolerance. Liver grafts are threatened in the long term by increasing hepatitis-related fibrosis, resulting most likely from immunological assault. Nowadays, the focus is on the longterm survival, quality of life (growth, academic performance, employment, self-fulfillment, fertility, raising a family, etc.), induction of tolerance, prevention of risks bound to decades of IS (nephrotoxicity and neurotoxicity, cardiovascular risk, de novo malignancies, etc.), and prevention of graft fibrosis. All these issues are fertile fields for younger scientists. Liver Transplantation 22 1284-1294 2016 AASLD., (© 2016 by the American Association for the Study of Liver Diseases.)

Methane is a common gas which has been reported to play a protective role in organ injury and presents an anti-inflammatory property. However, its effects on Concanavalin A (Con A)-induced autoimmune hepatitis (AIH) remain unknown. Thus, the aim of this study was to investigate the effects of methane on Con A-induced autoimmune hepatitis in mice and its underlying mechanism. Autoimmune hepatitis was induced by Con A (15 mg/kg) in healthy C57BL/6 mice and methane-rich saline (MS) (20 ml/kg) was intraperitoneally injected 30 min after the challenge with Con A. We found that methane treatment significantly reduced the elevated serum aminotransferase levels and ameliorated liver pathological damage. Furthermore, methane treatment obviously suppressed the secretion of proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6) and interleukin-1β (IL-1β) and increased anti-inflammatory cytokine interleukin-10 (IL-10). Moreover, we found that the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were highly increased while the activities of superoxide dismutase (SOD) and catalase (CAT) were decreased in liver with the injection of Con A, which was reversed by methane. Also, the data demonstrated that the phosphorylated IκB, NF-κB and P38 MAPK in liver were significantly down-regulated by methane. These results suggested that methane protected liver against Con A-induced injury through anti-inflammatory and anti-oxidative pathways., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Magnesium isoglycyrrhizinate (MGL) is a new stereoisomer of glycyrrhizic acid, which is clinically used as a hepatoprotective medicine with more potent effects and less side effects than glycyrrhizic acid. This study was designed to evaluate the protective effects and possible mechanism of MGL against concanavalin A (Con A)-induced autoimmune hepatitis. Hepatitis was induced by Con A in C57/6J mice with or without MGL administration; injury score and serum ALT were evaluated. The CD4(+) T-cells were isolated from splenocytes and challenged with Con A after coculturing with MGL. The injury score was significantly improved in MGL-treated mice after Con A challenging for 12 and 24 hours compared with those merely challenged with Con A. Similar trends were observed in the serum levels of ALT and AST. The most interesting result was that MGL administration significantly decreased the frequency of CD4(+)CD25(-)CD69(+) T-cells rather than CD4(+)CD25(+)CD69(+) T-cells in peripheral blood mononuclear cells, after Con A challenging 12 and 24 hours. Moreover, the serum ALT levels were markedly correlated with the frequency of CD4(+)CD25(-)CD69(+) cells, but only weakly correlated with CD4(+)CD25(+)CD69(+) cells in peripheral blood mononuclear cells. More importantly, MGL (5 mg/mL) almost completely eliminated the proliferation of the CD25(-)CD69(+) subset in primary CD4(+) T-cells after Con A challenge. Compared with merely Con A-challenged mice, those with MGL administration significantly demonstrated decreased NALP3, NLRP6, and caspase-3 expression, in which the NALP3 and caspase-3 downregulated in a dose-dependent manner. Our results indicate that MGL may have potential as a therapeutic agent in autoimmune hepatitis by ameliorating liver injury. Its molecular mechanism may be involved in inhibiting CD4(+)CD25(-)CD69(+) subset proliferation and downregulating inflammasome expression in liver tissue.

Patients transplanted for autoimmune hepatitis (AIH) are at risk of recurrent disease. Our current practice is to maintain long-term low-dose corticosteroids with additional immunosuppressive agents. This study describes the implications on patients' outcomes, sepsis, and osteoporosis. We collected data on patients transplanted between January 1999 and October 2014 in a single center who survived for more than 6 months. AIH recurrence was diagnosed by a combination of histology, raised immunoglobulin G levels, and exclusion of other etiologies. Sepsis was defined as any infection that resulted in significant morbidity or mortality. Osteoporosis was defined as a bone densitometry T score of less than -2.0 or evidence of osteoporosis-related fractures. Outcomes were assessed using Kaplan-Meier survival analysis methods. Seventy-three AIH patients underwent liver transplantation with a median follow-up of 94 months (interquartile range, 55-144). The cohort was mainly Caucasian (78%), female (79%), with type 1 AIH (90%), and a mean age of 43 ± 15 years. Overall survival was 92%, 90%, 86%, and 73%, and regraft-free survival was 86%, 81%, 78%, and 64% at 1, 3, 5, and 10 years, respectively. Five patients developed AIH recurrence, giving recurrence rates of 0%, 4%, 6%, and 11% at 1, 3, 5, and 10 years, respectively. Pneumonia was the most common infection, but gastroenteritis and cholangitis were the most recurrent. Freedom from sepsis was 91%, 82%, 80%, and 63%, and freedom from osteoporosis was 100%, 94%, 82%, and 58% at 1, 3, 5, and 10 years, respectively. Longterm low-dose corticosteroid in combination with other immunosuppressive agents seems to reduce AIH recurrence without jeopardizing patient and graft survival. Sepsis and osteoporosis did not occur more often compared to the published literature on liver transplant recipients., (© 2015 American Association for the Study of Liver Diseases.)

Unlabelled: Increasing evidence in recent years has suggested that B cells act as a crucial regulator in autoimmune diseases. However, little is known about their role in autoimmune hepatitis (AIH) and the underlying regulatory mechanisms. In this study, we show that B cells ameliorated experimental AIH (EAH) by suppressing CD4+ T-cell responses and that CD11b expression on B cells was required for the regulatory function of B cells. In vitro studies reveal that the suppressive function of CD11b was mediated by the impairment of T-cell antigen receptor (TCR) signaling transduction and the promotion of TCR down-regulation. Moreover, we show that the increased CD11b expression on B cells was interleukin (IL)-10 dependent and that additional IL-10 stimulation promoted CD11b expression on B cells, thereby enhancing B-cell regulatory effects., Conclusion: These findings reveal a previously unrecognized role for CD11b in B-cell regulatory function and its protective effect on EAH., (© 2015 by the American Association for the Study of Liver Diseases.)

Background: The role of donor-specific HLA antibodies (DSA) after pediatric liver transplantation (LTx) is not clearly established. We completed a cross-sectional study to characterize DSA in long-term survivors of pediatric LTx and assess the impact of C1q-binding DSA on allograft outcomes., Methods: Serum samples were collected at routine clinic visits from 50 pediatric LTx recipients classified into 3 clinical phenotypes: nontolerant (n = 18) with de novo autoimmune hepatitis (DAIH) and/or late acute cellular rejection (ACR); stable (n = 25) on maintenance tacrolimus; operationally tolerant (n = 7). Samples were blinded, and antibody detection was performed using Luminex single antigen class I and II beads. Patients with positive DSA were tested for C1q-binding DSA., Results: DSA were detected in 54% (n = 27) of the patients, with the majority directed at HLA class II antigens (DR, 41%; DQ, 53%). Patients with DSA were younger at the time of LTx (P = 0.016) and time of study (P = 0.024). Mean aspartate aminotransferase, alanine aminotransferase, total bilirubin, and gamma glutamyl transferase were higher in DSA-positive patients, though did not reach statistical significance. Nontolerant patients were significantly more likely to have DQ DSA (61%) compared to stable (20%) and tolerant (29%) patients (P = 0.021). The nontolerant phenotype was associated with DSA and C1q-binding DSA, with odds ratios of 13 (P = 0.015) and 8.6 (P = 0.006), respectively. The presence of DQ DSA was associated with DAIH and late ACR, with odds ratios of 12.5 (P = 0.004) and 10.8 (P = 0.006), respectively., Conclusions: Allograft dysfunction is not always evident in patients with DSA, but DQ DSA are strongly associated with DAIH, late ACR, and chronic rejection., Competing Interests: : The authors of this manuscript have no conflicts of interest to disclose other than the funding sources included above.

Objective: Astaxanthin, a potent antioxidant, exhibits a wide range of biological activities, including antioxidant, atherosclerosis and antitumor activities. However, its effect on concanavalin A (ConA)-induced autoimmune hepatitis remains unclear. The aim of this study was to investigate the protective effects of astaxanthin on ConA-induced hepatitis in mice, and to elucidate the mechanisms of regulation., Materials and Methods: Autoimmune hepatitis was induced in in Balb/C mice using ConA (25 mg/kg), and astaxanthin was orally administered daily at two doses (20 mg/kg and 40 mg/kg) for 14 days before ConA injection. Levels of serum liver enzymes and the histopathology of inflammatory cytokines and other maker proteins were determined at three time points (2, 8 and 24 h). Primary hepatocytes were pretreated with astaxanthin (80 μM) in vitro 24 h before stimulation with TNF-α (10 ng/ml). The apoptosis rate and related protein expression were determined 24 h after the administration of TNF-α., Results: Astaxanthin attenuated serum liver enzymes and pathological damage by reducing the release of inflammatory factors. It performed anti-apoptotic effects via the descending phosphorylation of Bcl-2 through the down-regulation of the JNK/p-JNK pathway., Conclusion: This research firstly expounded that astaxanthin reduced immune liver injury in ConA-induced autoimmune hepatitis. The mode of action appears to be downregulation of JNK/p-JNK-mediated apoptosis and autophagy.

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

Objectives: Celiac disease (CD) is common in patients with autoimmune liver disease (AILD); however, the long-term response to treatment of patients with AILDs coexistent with CD has not been explored in detail. The aim of the present study was to analyze the features and the long-term response to immunosuppressive treatment in children with autoimmune hepatitis (AIH) associated with CD., Methods: Retrospective and prospective evaluation of patients followed at a single center., Results: Among 79 patients with AIH, 15 (19%) had CD (9 type 1, 3 type 2, 3 seronegative). In the group of patients with AIH and CD, female sex was significantly more represented than in the group of patients with AIH alone; also, in the former group, diagnosis was made significantly earlier (P < 0.05). All of the 15 patients on a gluten-free diet achieved sustained remission when treated with prednisone and azathioprine or cyclosporine. The mean period of follow-up was 73 months; discontinuation of therapy was attempted in 9 patients while in remission: 4 patients relapsed, 5 (33%) could definitively stop immunosuppressive treatment with a mean period of treatment-free sustained remission of 89 months (range 26-174). In the same period, treatment discontinuation, attempted in 24 of 64 patients with AIH without CD, was successful in 5 patients (8%; P < 0.05)., Conclusions: Patients with AIH coexisting with CD achieve treatment-free sustained remission in a significantly higher proportion, when compared with patients with AIH without CD, suggesting a possible long-term adjuvant effect of a gluten-free diet.

Objective: To determine the metabolic and immunological effects of the oral administration of DT56a, an enzymatic isolate of soybeans., Methods: DT56a was orally administered to mice in three animal models: leptin deficiency, high-fat diet (HFD) supplementation and immune-mediated hepatitis. Liver damage and immunological status were assessed., Results: Oral administration of DT56a to leptin-deficient (ob/ob) and HFD mice led to a significant reduction in serum triglyceride (TG) and total cholesterol (TC) levels. DT56a-treated mice in both models exhibited a significant reduction in hepatic levels of TG and marked alleviation of glycemic control as indicated by significant decreases in fasting blood glucose levels and glucose tolerance tests. The levels of liver enzymes were reduced. These metabolic effects were associated with altered distributions of regulatory T (Tregs) and natural killer T (NKT) cells. DT56a suppressed the immune-mediated liver damage induced by concanavalin A indicated by decreased liver enzymes and serum interferon-γ levels and by improved histology and decreased hepatic apoptosis. Oral administration of DT56a also alleviated immune-mediated hepatitis and affected Tregs and NKT cells., Conclusions: Oral administration of DT56a promotes a hepatoprotective effect associated with an alteration in the distribution of Tregs and NKT cells., (© 2012 The Authors. Journal of Digestive Diseases © 2012 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.)

It is unclear what roles TNF-α has in the development of autoimmune hepatitis (AIH) and whether AIH is responsive to anti-TNF-α. We recently developed a mouse model of fatal AIH that develops in PD-1-deficient mice thymectomized three days after birth, finding that CCR6-CCL20 axis-dependent migration of dysregulated splenic T cells is crucial to induce AIH. In this study, we show the indispensable role of TNF-α in the development of AIH. Administering anti-TNF-α prevented the induction, but treatment by anti-TNF-α after the induction did not suppress progression. Administering anti-TNF-α did not prevent splenic T-cell activation, but did suppress hepatic CCL20 expression. In contrast, administering anti-CCL20 suppressed AIH but not elevated serum TNF-α levels. TNF-α stimulation enhanced CCL20 expression in hepatocytes. These findings suggest that TNF-α is essential in the induction of AIH through upregulation of hepatic CCL20 expression, which allows migration of dysregulated splenic T cells., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Curcumin, a polyphenol extracted from the plant curcuma longa, exhibits a number of pharmacological properties and has been used for the treatment of inflammatory diseases. However, the potential protective effects of curcumin in inflammatory liver diseases have not been clearly elucidated. Thus, the current study aimed to investigate the beneficial effects of curcumin on hepatic injury induced by concanavalin A (Con A), and its possible molecular mechanisms in mice. Acute live injury model was established successfully by intravenous administration of Con A (15mg/kg) in male C57BL/6 mice. Curcumin was administered to mice 2h prior to Con A injection. It was found that curcumin pretreatment significantly protected animals from T cell-mediated hepatitis as evidenced by decreased elevation of serum ALT, associated with reduced hepatic necrosis, apoptosis and mortality. In addition, curcumin pretreatment markedly reduced hepatic oxidative stress and pro inflammatory cytokines, including TNF-α and IFN-γ. Furthermore, curcumin pretreatment dramatically suppressed the releasing of high-mobility group box-1 (HMGB1) in liver tissues. These results suggest that curcumin pretreatment protects the mice from Con A-induced liver injury via inhibiting hepatocyte oxidative stress, inflammation and releasing of HMGB1., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background & Aims: Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease of unknown etiology. Autoreactive T cells are thought to mediate liver injury, but the pathogenesis of AIH is poorly understood because of the lack of suitable animal models. We established a mouse model to investigate liver-specific T-cell responses and assess the effects and regulation of autoreactive CD8(+) T cells in the pathogenesis of AIH., Methods: We generated transgenic mice expressing the influenza virus hemagglutinin (HA) autoantigen under control of mouse albumin regulatory elements and alpha-fetoprotein enhancers (Alb) specifically in the liver (Alb-HA mice); they were crossed with mice that express a specific T-cell receptor (TCR) (CL4-TCR). CL4-TCR transgenic CD8(+) T cells were also adoptively transferred into Alb-HA mice. We investigated immunologic mechanisms of CD8(+) T cell-induced liver damage and of counteracting peripheral tolerance., Results: The double-transgenic mice (Alb-HA/CL4-TCR) spontaneously developed chronic, autoimmune-mediated hepatitis, characterized by necroinflammatory lesions, hepatic fibrosis, and increased levels of aminotransferase; these features resembled those of AIH. Interestingly, most liver-infiltrating, HA-specific CD8(+) T cells had an anergic phenotype; regulatory CD4(+)CD25(+)Foxp3(+) T cells accumulated in the inflamed liver., Conclusions: The continuous development of a few, HA-specific CD8(+) effector T cells is sufficient to induce chronic hepatitis. Peripheral tolerance mechanisms such as induction of T-cell anergy and accumulation of regulatory CD4(+)CD25(+)Foxp3(+) T cells protect the liver from severe damage. Our mouse model that spontaneously develops chronic autoimmune-mediated hepatitis provides a new tool to investigate autoantigen-specific T-cell responses and regulatory mechanisms involved in the prevention and pathogenesis of AIH., (Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

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

Liver transplantation has become a standard option in the management of patients with end-stage liver disease. It is now evident that the most common etiology of long-term graft dysfunction is the recurrence of the primary liver disease. Autoimmune liver disorders such as autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis recur between 15 to 30% of the graft recipients. The clinical expression of this recurrence tends to be milder; the diagnosis is only established in many patients by findings in the liver biopsy. This milder clinical expression may be due to the use of immunosuppressive therapy for the prevention of organ rejection and it may also be modulating immune mechanisms that underlie these conditions. The recurrence of hepatitis C virus infection is characterized by an accelerated progression towards cirrhosis and hepatic failure due to the lack of an effective immunoprophylaxis program and an effective antiviral therapy. The recurrence of hepatitis B is uncommon due to the availability on an effective immunoprophylaxis program with effective antiviral agents. The familial amyloidotic polyneuropathy is a genetic condition residing in the hepatocyte that produces a mutation of transthyretin; this abnormal protein is deposited in peripheral nerves, gastrointestinal tract, heart, and kidneys. The liver from these patients, apart from producing this abnormal protein, is otherwise normal, and has been used as an organ for recipients in dire need of a liver transplant, such as patients with hepatocellular carcinoma. This approach is known as domino liver transplantation. As these recipients are followed long term, they may develop de novo amyloidosis. In summary, the underlying liver condition that led to endstage liver disease and liver transplantation may recur after liver transplantation. The clinical expression of the recurrence of the hepatic disease is modulated by the immunosuppression program unless we have an effective immunoprophylaxis and antiviral agents such as in hepatitis B.

Unlabelled: Elucidating cellular mechanisms that maintain the intrahepatic immune balance is crucial to our understanding of viral or autoimmune liver diseases and allograft acceptance. Liver sinusoidal endothelial cells (LSECs) play an important role in modifying local immune responses to tolerance in major histocompatibility complex (MHC) I-restricted models, whereas their contribution in the MHCII context is still controversial. In an MHCII chimeric mouse model that excludes MHCII-mediated antigen presentation by professional antigen-presenting cells, we demonstrated that LSECs prime CD4(+) T cells to a CD45RB(low) memory phenotype lacking marker cytokine production for effector cells that was stable in vivo following immunogenic antigen re-encounter. Although these cells, which we term T(LSEC), had the capacity to enter lymph nodes and the liver, they did not function as effector cells either in a delayed-type hypersensitivity reaction or in a hepatitis model. T(LSEC) inhibited the proliferation of naïve CD4(+) T cells in vitro although being CD25(low) and lacking expression of forkhead box protein (FoxP)3. Furthermore, these cells suppressed hepatic inflammation as monitored by alanine aminotransferase levels and cellular infiltrates in a T cell-mediated autoimmune hepatitis model in vivo., Conclusion: T(LSEC) first described here might belong to the expanding group of FoxP3(-) regulatory T cells. Our findings strengthen the previously discussed assumption that CD4(+) T cell priming by nonprofessional antigen-presenting cells induces anti-inflammatory rather than proinflammatory phenotypes. Because recruitment of CD4(+) T cells is increased upon hepatic inflammation, T(LSEC) might contribute to shifting antigen-dependent immune responses to tolerance toward exogenous antigens or toward endogenous self-antigens, especially under inflammatory conditions.

Background & Aims: T cell-mediated hepatitis is a leading cause of acute liver failure; there is no effective treatment, and the mechanisms underlying its pathogenesis are obscure. The aim of this study was to investigate the immune cell-signaling pathways involved-specifically the role of signal transducer and activator of transcription 3 (STAT3)-in T cell-mediated hepatitis in mice., Methods: T cell-mediated hepatitis was induced in mice by injection of concanavalin A (Con A). Mice with myeloid cell-specific and T-cell-specific deletion of STAT3 were generated., Results: STAT3 was activated in myeloid and T cells following Con A injection. Deletion of STAT3 specifically from myeloid cells exacerbated T-cell hepatitis and induced STAT1-dependent production of a T helper cell (Th)1 cytokine (interferon [IFN]-gamma) and to a lesser extent of Th17 cytokines (interleukin [IL]-17 and IL-22) in a STAT1-independent manner. In contrast, deletion of STAT3 in T cells reduced T cell-mediated hepatitis and IL-17 production. Furthermore, deletion of IFN-gamma completely abolished Con A-induced T-cell hepatitis, whereas deletion of IL-17 slightly but significantly reduced such injury. In vitro experiments indicated that IL-17 promoted liver inflammation but inhibited hepatocyte apoptosis., Conclusions: Myeloid STAT3 activation inhibits T cell-mediated hepatitis via suppression of a Th1 cytokine (IFN-gamma) in a STAT1-dependent manner, whereas STAT3 activation in T cells promotes T-cell hepatitis to a lesser extent, via induction of IL-17. Therefore, activation of STAT3 in myeloid cells could be a novel therapeutic strategy for patients with T-cell hepatitis.

Antigen-specific T cells play a pivotal role in adaptive immune responses. However, they also contribute to the progression of a variety of diseases including autoimmune disorders, graft rejection and graft-versus-host disease (GVHD). Non-specific immune-ablation treatments compromise the ability of the host to respond to infection, whereas the selective removal of epitope-specific T cells could theoretically ameliorate T-cell-mediated pathology while preserving the rest of the host immune function. In this study we investigated whether it is possible to destroy specific unwanted antigen-specific T cells by incubating polyclonal T-cell populations with major histocompatibility complex (MHC) tetramers that are conjugated to the ribosomal-inactivating toxin, saporin. This strategy resulted in a dramatic reduction in the number of targeted antigen (Ag)-specific CD8 T cells with no observable bystander toxicity in vitro. Moreover, in a model of transferable T-cell-dependent neurological disease induced by intracerebral (i.c.) lymphocytic choriomeningitis virus (LCMV) infection, the targeted killing of LCMV-specific CD8 T cells extended the survival of mice or fully prevented their death, depending on the dose of cells transferred. In addition, the tetramer- saporin conjugate also reduced liver damage in a model of donor T-cell-mediated hepatic destruction. These data provide a proof of principle that MHC tetramers could be exploited for the elimination or clinical manipulation of T-cell responses by linking effector molecules (a toxin in this case) to MHC tetramers. Also, the results suggest that it may be feasible to remodel T-cell responses, especially in immunocompromised hosts who receive adoptive cell transfers with many potential alloreactive cells.

Antibodies to CD25 (anti-CD25) were used clinically to achieve immunosuppression in autoimmune disease, while the possibility of anti-antibodies generation influenced its efficiency. Here we reported that DNA vaccine encoding the extracellular domain of murine CD25 gene (pCD25-ECD) elicited anti-CD25 antibody production in BALB/c mice and subsequently prevents the host against ConA-induced autoimmune hepatitis. We found that serum CD25-specific antibodies were generated after vaccination with pCD25-ECD. Moreover, high levels of IL-4, IL-10 and anti-CD25 antibody were produced by splenocytes of vaccinated mice after CD25 protein restimulation in vitro. Furthermore, we demonstrated that the vaccinated mice suffered less from liver injury induced by ConA, accompanied by the reduction of pathogenic CD4+ T cells. Finally, we showed that the immunized serum could cause cytolysis of activated CD4+ T cells in vitro, depending on complements activation. Our study showed pCD25-ECD induced self anti-CD25 antibodies which executed immunosuppression in autoimmune hepatitis via antibody-complement pathway.

We investigated the effects of the recently synthetized NO donating agent GIT-27NO on the growth of human androgen independent and androgen dependent PC3 and LnCap cells xenografted in nude mice. We also tested the effects of GIT-27NO in the preclinical model of cell-mediated immunoinflammatory hepatitis that can be induced in mice by Concanavalin A (ConA) and that has been shown to benefit from the treatment with NO donating agents such as NO-aspirin. In agreement with in vitro data showing dose-dependent reduction of PC3 and LnCap cell viability with GIT-27NO, the i.p. treatment of mice xenografted with either of these cells with GIT-27NO significantly inhibited their growth as compared to the mice-treated with its vehicle. In addition, GIT-27NO given -24 and -1 h prior to e.v. challenge with 20 mg/kg ConA significantly suppressed the increase of transaminases that occurred 8 h after challenge in the control mice that received the vehicle. In addition, relative to these latter groups of mice, the histological signs of inflammatory hepatitis were markedly reduced in ConA-challenged mice that received GIT-27NO. In the hepatitis model, GIT-27NO was equally effective in preventing ConA-induced hepatitis regardless of whether it was administered intra peritoneally or per os. These data confirm that GIT-27NO is a powerful anticancer agent also endowed with pharmacological properties to prevent the development of cell-mediated murine immunoinflammatory hepatitis.

The modulation influence of Misgurnus anguillicaudatus polysaccharide on the expression of nitric oxide synthase (NOS), B cell lymphoma/leukemia-2 (Bcl-2, hepatocyte apoptosis inhibitor) and Bcl-2 associated X protein (Bax, hepatocyte apoptosis promoter) in mice's liver with immunological hepatic injury was studied. Immunological hepatic injury was induced by lipopolysaccharide (LPS ip, 0.2 mg kg(-1)) in bacillus calmette-guerin (BCG ip, 0.15 g kg(-1), once, before 7 days) primed mice. The mice were treated with M. anguillicaudatus polysaccharides (MAP) at doses of 30 mg kg(-1), 60 mg kg(-1), respectively, ig, once a day, and sacrificed on the 8th day after ip LPS for 4 h. In comparison to the normal mice, the nitric oxide production, serum alanine aminotransferase (sALT) and serum glutathione s-transferase (sGST) levels were increased significantly, iNOS and Bax expression were up-regulated by 16.5 times (P<0.001 vs. normal animal group) and 0.43 times (P<0.05, vs. normal animal group) respectively, cNOS expression was not apparently changed, and no Bcl-2 expression was found in immunological hepatic injury mice. The M. anguillicaudatus polysaccharide (30 mg kg(-1)) could reduce sALT, sGST and nitric oxide production levels (vs. BCG-LPS model control group) by 25.1%, 42.6% and 17.8% respectively, and the expression of iNOS and Bax was decreased (vs. BCG-LPS model control group) by 80.3% and 38.4%, while the expression of cNOS and Bcl-2 increased (vs. BCG-LPS model control group) by 58.7% and 352%, respectively.

Background: Recently, we found that portal vein tolerance is associated with generation of Th2 cells and apoptosis of Th1 cells in the liver, which is regulated by antigen (Ag)-presenting dendritic cells (DCs) in the periportal area and sinusoids., Aim: In this study, we tested whether the periportal and sinusoidal DCs, which were loaded with an Ag in vivo, can inhibit liver injury caused by Th1 cells activated by the Ag administered systemically., Methods: Ag-specific hepatitis model was created by adoptively transferring ovalbumin (OVA)-specific CD4(+) T cells to BALB/c mice and venous injection of OVA-containing liposomes. Liver CD11c(+) cells obtained from mice fed OVA were then transferred into these mice., Results: The transfer of liver CD11c(+) cells from OVA-fed mice completely inhibited hepatic injury, which was associated with apoptosis of OVA-specific CD4(+) T cells and emergence of Th2 cells in the liver. Transfer of CD11c(+) cells and subcutaneous OVA challenge led to enhancement of OVA-specific IgE Ab as well as Th2 cytokine responses in the recipient mice., Conclusions: Periportal and sinusoidal DCs loaded with an Ag in the portal vein can induce Th2 response in the liver and prevent hepatic injury caused by Th1 cells.

Background: Hepatitis B virus (HBV) infection afflicts Asia population and, in Hong Kong, about 10% was Hepatitis B surface antigen carrier. It is still one of the major issues under investigation. Herbal medicine KY88 composed of Fructus Schisandrae possessing immunomodulatory property was adopted by Chinese medicine practitioner for treatment of acute and chronic HBV infection. However, the underlying impact on host immune system is not fully understood., Materials and Methods: Twenty-three healthy volunteers infected with HBV were taken peripheral venous blood from which the blood cells involved in simple host immunity was obtained., Results: It was found that the circulating monocyte count significantly drop after 2weeks of KY88 therapy whereas the fall did not return back to baseline. Circulating white blood cell, neutrophil and lymphocyte, however, did not show obvious change upon commencement of KY88 therapy., Conclusion: It was postulated that reduction in circulating monocyte count may reduce the self-inflicted host immune injury to hepatocyte which may testify the hepatoprotective ability of the herb. But, the exact mechanism on how immunomodulatory properties of the herbal medicine protect chronic HBV carriers from liver injury remains a myth.

Aim: To investigate the role of p38 mitogen-activated protein kinase (p38MAPK) in murine experimental autoimmune hepatitis (EAH)., Methods: To induce EAH, the syngeneic S-100 antigen emulsified in complete Freud's adjuvant was injected intraperitoneally into adult male C57Bl/6 mice. Liver injury was assessed by serum ALT and liver histology. The expression and activity of p38 MAPK were measured by Western blot and kinase activity assays. In addition, DNA binding activities of nuclear factor kappa B (NF-kappaB) were analyzed by electrophoretic mobility shift assay. The effects of SB203580, a specific p38 MAPK inhibitor, on liver injuries and expression of proinflammatory cytokines (interferon-gamma, IL-12, IL-1beta and TNF-alpha) were observed., Results: The activity of p38 MAPK and NF-kappaB was increased and reached its peak 14 or 21 d after the first syngeneic S-100 administration. Inhibition of p38 MAPK activation by SB203580 decreased the activation of NF-kappaB and the expression of proinflammatory cytokines. Moreover, hepatic injuries were improved significantly after SB203580 administration., Conclusion: p38 MAPK and NF-kappaB play an important role in an animal model of autoimmune hepatitis (AIH) induced by autoantigens.

It is controversial whether steroid therapy should be continued to prevent the recurrence of autoimmune hepatitis (AIH) in patients who have undergone liver transplantation (LTx) due to AIH. We report a case of recurrent autoimmune hepatitis after LTx despite a persistently normal range of alanine aminotransferase (ALT). A 50-year-old woman was admitted to our hospital because of jaundice and severe liver dysfunction, where she was diagnosed with liver failure due to AIH. Steroid therapy was not effective enough and the patient received living-donor LTx in 1999. Following the operation, the level of ALT was maintained within a normal range and anti-nuclear antibody (ANA) became negative, however, the serum level of IgG gradually elevated and ANA became positive, while platelets decreased. A liver biopsy performed 6 years after LTx showed histological findings of AIH and she was diagnosed with recurrent AIH. A recurrence of AIH may occur after LTx even if the level of ALT remains within a normal range. We consider that a protocol liver biopsy should be performed in patients who undergo LTx due to AIH to decide the indication for steroid therapy.

1. Paeoniflorin is one of the main effective components of the total glucosides of paeony (TGP) extracted from the root of Paeonia lactiflora which has been used for gynaecological problems and for cramp, pain and giddiness for over 1,500 years in Chinese medicine. Anti-inflammatory, antioxidative, antihepatic injury and immunoregulatory activities of TGP have been extensively proved in our laboratory for many years. Our present study investigates the effects and mechanisms of paeoniflorin on immunological liver injury in mice. 2. A model of immunological liver injury was induced by tail vein injection of bacillus Calmette-Guérin (BCG) and lipopolysaccharide (LPS) in mice. Activities of serum alanine aminotransferase (ALT) were measured by biochemical methods. Hepatic tissue sections were stained with haematoxylin and eosin and examined under a light microscope. Tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, lipopolysaccharide binding protein (LBP) and CD14 mRNA (messenger ribonucleic acid) expression in mouse liver were determined by semiquantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. 3. Immunological liver injury induced by BCG plus LPS was successfully duplicated. Serum ALT activities were significantly decreased by paeoniflorin. (25, 50, 100 mg/kg). Histological examination demonstrated that paeoniflorin could attenuate the area and extent of necrosis and reduce the immigration of inflammatory cells. The increase in TNF-alpha, LBP and CD14 mRNA expression in mouse liver after BCG and LPS injection was significantly decreased by paeoniflorin (100 mg/kg) and was changed by paeoniflorin (25, 50 mg/kg) at different time-point. The augmentation of IL-6 mRNA in mouse liver was markedly increased by paeoniflorin at 1 h and 3 h after LPS injection. 4. Paeoniflorin could significantly protect against immunological liver injury in mice. TNF-alpha, IL-6, LBP and CD14 mRNA expression in mouse liver may be involved in BCG plus LPS induced liver injury. The protective mechanism of paeoniflorin might be partially related to modulation of TNF-alpha, IL-6, LBP and CD14 mRNA expressions in mouse liver.

Adenine nucleotides induce danger signals in T cells via purinergic receptors, raising the question whether they exert similar effects on innate immunity. Here we show that micromolar concentrations of nicotinamide adenine dinucleotide (NAD) induce a rapid increase of annexin V staining in NKT cells in vitro, a response that requires expression of P2X(7)Rs. Consistent with this result, treatment of mice with NAD causes a temporary decrease of NKT cells in the liver and protects from Con A- and alpha-galactosylceramide-induced hepatitis, both of which require functional NKT cells. Resistance to liver injury is associated with decreased cytokine production by NKT cells in NAD-treated mice. In contrast, when NAD is injected into Con A- or alpha-galactosylceramide-primed mice, liver injury is exacerbated and cytokine production by NKT cells is increased. This effect is caused by P2X(7)R-mediated stimulation of activated NKT cells. In agreement, mice lacking P2X(7)Rs on lymphocytes suffer reduced liver injury, and animals lacking ADP-ribosyltransferase, the enzyme that uses NAD to attach ADP-ribosyl groups to cell surfaces, are also resistant to Con A-induced hepatitis. These results prompt the conclusion that engagement of P2X(7)Rs on NKT cells inhibits naive, while stimulating activated cells, resulting in suppression or stimulation of autoimmune hepatitis.