Repeated concanavalin A challenge in mice induces an interleukin 10-producing phenotype and liver fibrosis

Oroxylin A inhibited autoimmune hepatitis-induced liver injury and shifted Treg/Th17 balance to Treg differentiation

Autoimmune hepatitis (AIH) is a kind of autoimmune disease mediated by T cells, and its incidence is gradually increasing in the world. Oroxylin A (OA) is one of the major bioactive flavonoids that has been reported to inhibit inflammatory. Here, an AIH model of mouse was induced by Concanavalin A (Con A). It found that serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were decreased in mice with the treatment of OA. Hematoxylin-eosin staining showed that the liver injury was attenuated by OA, and TUNEL staining indicated that the cells apoptosis of liver was weakened in mice with OA treatment. ELISA analysis of cytokines and chemokines suggested that OA reduced the expression of IL-6, IL-17A, chemokine ligand 2 (CCL2), C-X-C motif chemokine ligand 1 (CXCL1) and CXCL10, but promoted the expression of IL-10 and TGF-β in mice. The mRNA levels of Il-17a in liver and spleen tissues were also significantly decreased, on the contrary, the mRNA levels of Il-10 in liver and spleen tissues were increased. The proportion of Treg/Th17 detected by flow cytometry revealed that OA promoted the differentiation of Treg and inhibited the differentiation of Th17 both in the liver and spleen. The results of this study demonstrated the inhibitory effects of OA on AIH-induced liver injury and the inflammatory response of AIH, and revealed that OA affected the balance of Treg/Th17 and shifted the balance toward Treg differentiation. It provided new potential drugs for the prevention of AIH.

Animal and Organoid Models of Liver Fibrosis

Liver fibrosis refers to the process underlying the development of chronic liver diseases, wherein liver cells are repeatedly destroyed and regenerated, which leads to an excessive deposition and abnormal distribution of the extracellular matrix such as collagen, glycoprotein and proteoglycan in the liver. Liver fibrosis thus constitutes the pathological repair response of the liver to chronic injury. Hepatic fibrosis is a key step in the progression of chronic liver disease to cirrhosis and an important factor affecting the prognosis of chronic liver disease. Further development of liver fibrosis may lead to structural disorders of the liver, nodular regeneration of hepatocytes and the formation of cirrhosis. Hepatic fibrosis is histologically reversible if treated aggressively during this period, but when fibrosis progresses to the stage of cirrhosis, reversal is very difficult, resulting in a poor prognosis. There are many causes of liver fibrosis, including liver injury caused by drugs, viral hepatitis, alcoholic liver, fatty liver and autoimmune disease. The mechanism underlying hepatic fibrosis differs among etiologies. The establishment of an appropriate animal model of liver fibrosis is not only an important basis for the in-depth study of the pathogenesis of liver fibrosis but also an important means for clinical experts to select drugs for the prevention and treatment of liver fibrosis. The present study focused on the modeling methods and fibrosis characteristics of different animal models of liver fibrosis, such as a chemical-induced liver fibrosis model, autoimmune liver fibrosis model, cholestatic liver fibrosis model, alcoholic liver fibrosis model and non-alcoholic liver fibrosis model. In addition, we also summarize the research and application prospects concerning new organoids in liver fibrosis models proposed in recent years. A suitable animal model of liver fibrosis and organoid fibrosis model that closely resemble the physiological state of the human body will provide bases for the in-depth study of the pathogenesis of liver fibrosis and the development of therapeutic drugs.

HGF and IL-10 expressing ALB::GFP reporter cells generated from iPSCs show robust anti-fibrotic property in acute fibrotic liver model

BACKGROUND

Cell therapy using hepatocytes derived from stem cells has been regarded as a promising alternate to liver transplantation. However, the heterogeneity of these hepatocytes makes them unsuitable for therapeutic use. To overcome this limitation, we generated homogenous hepatocyte like induced hepatocyte-like (iHep) cells.

METHODS

iHep cells were generated from induced pluripotent stem cells (iPSCs) integrated with the albumin (ALB) reporter gene. The therapeutic properties of these iHep cells were investigated after transplantation in fibrotic liver tissues of a mouse model.

RESULTS

The iHep cells expressed hepatocyte specific genes and proteins, and exhibited high levels of hepatocyte growth factor (HGF) and interleukin (IL)-10 expressions. Transplantation of iHep cells significantly decreased thioacetamide (TAA)-induced liver fibrosis, apoptotic cells in the liver, and ameliorated abnormal liver function. Liver tissues engrafted with iHep cells exhibited decreased expression of pro-inflammatory factors such as transforming growth factor (TGF)-β, IL-6, and monocyte chemo attractant protein (MCP)-1. Furthermore, an increased number of proliferating hepatocytes and human albumin-expressing iHep cells were detected in mice liver.

CONCLUSIONS

This study has investigated and proven the liver regeneration potential of genome-edited iHep cells and promises to be a strong foundation for further studies exploring cell therapy as an alternative therapeutic option for the treatment of liver fibrosis.

Transplantation of human adipose tissue derived-SVF enhance liver function through high anti-inflammatory property

Although human adipose tissue-derived stromal vascular fraction (SVF) has been considered a promising source of stem cells, its characteristics relevant to treatment of a damaged liver have not been fully elucidated. In the present study, we sought to characterize the property of human SVF and determine the therapeutic utility of SVF in the liver cirrhosis model. We performed microarray, quantitative (q)-PCR experiments, and in vivo therapeutic assays using a liver cirrhotic mouse model. q-PCR results revealed that hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF)-A, Interleukin (IL)-10 and microRNA (miR)-146 were more highly upregulated in SVF than in human adipose-derived mesenchymal stem cells (ASCs). The SVF culture medium (CM) inhibited the activation of hepatic stellate cells in vitro. Injection of SVF significantly suppressed TAA-induced liver fibrosis and repaired liver function by inhibition of infiltrating inflammatory cells and induction of capillary/hepatocyte regeneration in vivo. Injection of IL-10 siRNA treated SVF cells decreased anti-inflammation and anti-fibrotic effects in TAA-induced mice liver. Our data indicate that SVF show a high anti-inflammatory property for treating fibrotic liver diseases through IL-10 secretion. Therefore, SVF might be a novel therapeutic alternative for the treatment of liver cirrhosis in clinical settings.

IL-10-secreting human MSCs generated by TALEN gene editing ameliorate liver fibrosis through enhanced anti-fibrotic activity

Interleukin 10 secreting genome-edited MSCs inhibited liver fibrosis and ameliorated abnormal liver function.

Endogenous IL-10 maintains immune tolerance but IL-10 gene transfer exacerbates autoimmune cholangitis

The immunomodulatory effect of IL-10 as an immunosuppressive and anti-inflammatory cytokine is well known. Taking advantage of our established mouse model of autoimmune cholangitis using 2-octynoic acid conjugated ovalbumin (2-OA-OVA) induction, we compared liver pathology, immune cell populations and antimitochondrial antibodies between IL-10 knockout and wild type mice immunized with 2-OA-OVA. At 10 weeks post immunization, portal inflammation and fibrosis were more severe in 2-OA-OVA immunized IL-10 knockout mice than in wild type mice. This was accompanied by significant higher levels of collagen I and III expression, T, NK and NKT subsets in liver and IgG anti-mitochondrial autoantibodies (AMAs) compared to 2-OA-OVA immunized wild type mice, suggesting that endogenous IL-10 is necessary for the maintenance of immune tolerance in primary biliary cholangitis (PBC). Further, we investigated whether administration of exogenous IL-10 could prevent PBC by administration of IL-10 expressing recombinant adeno-associated virus (AAV-IL-10) either 3 days before or 3 weeks after the establishment of liver pathology. Interestingly, administration of AAV-IL-10 resulted in increased liver inflammation and fibrosis, accompanied by increases in IFN-γ in liver CD4⁺ T cell, granzyme B, FasL, and CD107a in liver CD8⁺ T and NKT cells, and granzyme B and FasL in liver NK cells of AAV-IL-10 administered mice compared with control mice. Furthermore, administration of AAV-IL-10 significantly increased levels of proinflammatory cytokines and chemokines (IFN-γ, TNF-α, CXCL9 and CXCL10) and collagen I and III production in naïve mice, together with increase in immune cell infiltration and collagen deposition in the liver, suggesting a role of IL-10 in fibrosis. In conclusion, our data demonstrate that endogenous IL-10 is critical in the maintenance of immune tolerance but exogenous administration of IL-10 exacerbates liver inflammation and fibrosis. Furthermore, the distinctive presence of inflammatory immune cell populations and collagen expression in AAV-IL-10 treated naïve mice cautions against the clinical use of exogenous IL-10 in patients with autoimmune cholangitis.

Adenovirus‑mediated knockdown of activin A receptor type 2A attenuates immune‑induced hepatic fibrosis in mice and inhibits interleukin‑17‑induced activation of primary hepatic stellate cells

Fibrosis induces a progressive loss of liver function, thus leading to organ failure. Activins are secreted proteins that belong to the transforming growth factor (TGF)-β superfamily, which initiate signaling by binding to their two type II receptors: Activin A receptor type 2A (ACVR2A) and activin A receptor type 2B. Previous studies that have explored the mechanisms underlying immune-induced hepatic fibrosis have mainly focused on TGF-β signaling, not activin signaling. To investigate the role of the activin pathway in this disease, adenovirus particles containing short hairpin (sh)RNA targeting ACVR2A mRNA (Ad-ACVR2A shRNA) were administered to mice, which were chronically treated with concanavalin A (Con A). The pathological changes in the liver were evaluated with hematoxylin/eosin staining, Masson trichrome staining and immunohistochemical assay. The results detected an increase in serum activin A and liver ACVR2A in Con A-treated animals. Conversely, liver function was partially restored and fibrotic injury was attenuated when activin signaling was blocked. In addition, the activation of hepatic stellate cells (HSCs) in response to Con A was suppressed by Ad-ACVR2A shRNA, as evidenced by decreased α-smooth muscle actin, and type I and IV collagen expression. Furthermore, primary mouse HSCs (mHSCs) were activated when exposed to interleukin (IL)-17A or IL-17F, which are two major cytokines produced by cluster of differentiation 4⁺ T helper 17 cells. The levels of activin A, type I and IV collagen were determined with ELISA kits and the expression of fibrotic molecules was determined with western blot analysis. Conversely, blocking activin/ACVR2A impaired the potency of HSCs to produce collagens in response to IL-17s. In addition, C terminus phosphorylation of Smad2 on Ser465 and Ser467, induced by either Con A in the liver or by IL-17s in mHSCs, was partly inhibited when activin A/ACVR2A signaling was suppressed. Collectively, the present study demonstrated an involvement of activated activin A/ACVR2A/Smad2 signaling in immune-induced hepatic fibrosis.

Magnolol Attenuates Concanavalin A-induced Hepatic Fibrosis, Inhibits CD4+ T Helper 17 (Th17) Cell Differentiation and Suppresses Hepatic Stellate Cell Activation: Blockade of Smad3/Smad4 Signalling

Magnolol is a pharmacological biphenolic compound extracted from Chinese herb Magnolia officinalis, which displays anti-inflammatory and antioxidant effects. This study was aimed at exploring the potential effect of magnolol on immune-related liver fibrosis. Herein, BALB/c mice were injected with concanavalin A (ConA, 8 mg/kg/week) up to 6 weeks to establish hepatic fibrosis, and magnolol (10, 20, 30 mg/kg/day) was given to these mice orally throughout the whole experiment. We found that magnolol preserved liver function and attenuated liver fibrotic injury in vivo. In response to ConA stimulation, the CD4⁺ T cells preferred to polarizing towards CD4⁺ T helper 17 (Th17) cells in liver. Magnolol was observed to inhibit Th17 cell differentiation in ConA-treated liver in addition to suppressing interleukin (IL)-17A generation. Hepatic stellate cells were activated in fibrotic liver as demonstrated by increased alpha smooth muscle actin (α-SMA) and desmin. More transforming growth factor (TGF)-β1 and activin A were secreted into the serum. Magnolol suppressed this abnormal HSC activation. Furthermore, the phosphorylation of Smad3 in its linker area (Thr179, Ser 204/208/213) was inhibited by magnolol. In vitro, the recombinant IL-17A plus TGF-β1 or activin A induced activation of human LX2 HSCs and promoted their collagen production. Smad3/Smad4 signalling pathway was activated in LX2 cells exposed to the fibrotic stimuli, as illustrated by the up-regulated phospho-Smad3 and the enhanced interaction between Smad3 and Smad4. These alterations were suppressed by magnolol. Collectively, our study reveals a novel antifibrotic effect of magnolol on Th17 cell-mediated fibrosis.

Treatment with abatacept prevents experimental dermal fibrosis and induces regression of established inflammation-driven fibrosis

OBJECTIVE

Activated T cells are the main component of the inflammatory skin infiltrates that characterise systemic sclerosis (SSc). Our aim was to investigate the efficacy of abatacept, which tempers T-cell activation, in reducing skin fibrosis in complementary mouse models of SSc.

METHODS

The antifibrotic properties of abatacept were evaluated in the mouse models of bleomycin-induced dermal fibrosis and sclerodermatous chronic graft-versus-host disease, reflecting early and inflammatory stages of SSc. Thereafter, we studied the efficacy of abatacept in tight skin (Tsk-1) mice, an inflammation-independent mouse model of skin fibrosis.

RESULTS

Abatacept efficiently prevented bleomycin-induced skin fibrosis and was also effective in the treatment of established fibrosis. In this model, abatacept decreased total and activated T-cell, B-cell and monocyte infiltration in the lesional skin. Abatacept did not protect CB17-SCID mice from the development of bleomycin-induced dermal fibrosis, which supports that T cells are necessary to drive the antifibrotic effects of abatacept. Upon bleomycin injections, skin interleukin (IL) 6 and IL-10 levels were significantly reduced upon abatacept treatment. Moreover, treatment with abatacept ameliorated fibrosis in the chronic graft-versus-host disease model, but demonstrated no efficacy in Tsk-1 mice. The tolerance of abatacept was excellent in the three mouse models.

CONCLUSIONS

Using complementary models, we demonstrate that inhibition of T-cell activation by abatacept can prevent and induce the regression of inflammation-driven dermal fibrosis. Translation to human disease is now required, and targeting early and inflammatory stages of SSc sounds the most appropriate for positioning abatacept in SSc.

Antifibrotic mechanism of deferoxamine in concanavalin A induced-liver fibrosis: Impact on interferon therapy

Iron-overload is a well-known factor of hepatotoxicity and liver fibrosis, which found to be a common finding among hepatitis C virus patients and related to interferon resistance. We aimed to elucidate the potential antifibrotic effect of deferoxamine; the main iron chelator, and its additional usefulness to interferon-based therapy in concanavalin A-induced immunological model of liver fibrosis. Rats were treated with deferoxamine and/or pegylated interferon-α for 6 weeks. Hepatotoxicity indices, oxidative stress, inflammatory and liver fibrosis markers were assessed. Concanavalin A induced a significant increase in hepatotoxicity indices and lipid peroxidation accompanied with a significant depletion of total antioxidant capacity, glutathione level and superoxide dismutase activity. Besides, it increased CD4(+) T-cells content and the downstream inflammatory cascades, including NF-κB, TNF-α, iNOS, COX-2, IL-6 and IFN-γ. Furthermore, α-SMA, TGF-β1 and hydroxyproline were increased markedly, which confirmed by histopathology. Treatment with either deferoxamine or pegylated interferon-α alone reduced liver fibrosis markers significantly and improved liver histology. However, some of the hepatotoxicity indices and oxidative stress markers did not improve upon pegylated interferon-α treatment alone, besides the remarkable increase in IL-6. Combination therapy of deferoxamine with pegylated interferon-α further improved all previous markers, ameliorated IL-6 elevation, as well as increased hepcidin expression. In conclusion, our study provides evidences for the potent antifibrotic effects of deferoxamine and the underlying mechanisms that involved attenuating oxidative stress and subsequent inflammatory cascade, as well as the production of profibrogenic factors. Addition of deferoxamine to interferon regimen for HCV patients may offer a promising adjuvant modality to enhance therapeutic response.

Immunologic Predictors of Liver Transplantation Outcomes in HIV-HCV Co-Infected Persons

Liver disease is a leading cause of mortality among HIV-infected persons in the highly active anti-retroviral therapy (HAART) era. Hepatitis C Virus (HCV) co-infection is prevalent in, and worsened by HIV; consequently many co-infected persons require liver transplantation (LT). Despite the need, post-LT outcomes are poor in co-infection. We examined predictors of outcomes post-LT. Immunologic biomarkers of immune activation, microbial translocation, and Th1/Th2 skewing were measured pre-LT in participants enrolled in a cohort of HIV infected persons requiring solid organ transplant (HIVTR). Predictive biomarkers were analyzed in Cox-proportional hazards models; multivariate models included known predictors of outcome and biomarkers from univariate analyses. Sixty-nine HIV-HCV co-infected persons with available pre-LT samples were tested: median (IQR) CD4+ T-cell count was 286 (210–429) cells mm^-3; 6 (9%) had detectable HIV RNA. Median (IQR) follow-up was 2.1 (0.7–4.0) years, 29 (42%) people died, 35 (51%) had graft loss, 22 (32%) were treated for acute rejection, and 14 (20%) had severe recurrent HCV. In multivariate models, sCD14 levels were significantly lower in persons with graft loss post-LT (HR 0.10 [95%CI 0.02–0.68]). IL-10 levels were higher in persons with rejection (HR 2.10 [95%CI 1.01–4.34]). No markers predicted severe recurrent HCV. Monocyte activation pre-LT may be mechanistically linked to graft health in HIV-HCV co-infection.

The effect of 4α,5α-epoxy-10α,14-dihydro-inuviscolide, a novel immunosuppressant isolated from Carpesium abrotanoides, on the cytokine profile in vitro and in vivo

The plant Carpesium abrotanoides (CA) is used in Asian herbal medicines as an insecticide and to treat bruises. However, the effect of single compounds from CA blooms and the mechanism of its immunosuppressive effect remain poorly understood. The aim of this study was to investigate the mechanism of the immunosuppressive effect in the three kinds of immune cells, and the immunosuppressive effect of CA bloom extract (CAE) in acute inflammation models (LPS and ConA-induced inflammation). Interleukin-6, IL-4, IL-13, IFNγ, and IL-10-but not TNFα-were significantly reduced in a dose-dependent manner by 4α,5α-epoxy-10α,14-dihydro-inuviscolide (INV). Furthermore, INV inhibited NF-κB transcriptional activation and IL-10 promoter activity in the same manner as for Bay11. Meanwhile, treatment with dexamethasone reduced the levels of IFNγ, but not IL-10, and resulted in no change in NF-κB transcriptional activation or the IL-10 promoter. INV did not affect PMA-induced IκB kinase complex phosphorylation, IκB degradation, or MAPK and the nuclear translocation of p65, as with DEX. The in vivo, CAE has an immunosuppressive effect on the LPS-induced inflammation response model by inhibiting the plasma level of IFNγ and IL-6 levels. CAE treatment also tends to attenuate the plasma level of IFNγ, IL-4, and IL-6 in ConA-induced inflammation. These findings indicate that INV causes the reduction of the cytokine profile by blocking the NF-κB transcription factor activation and the molecular mechanism by which INV operates could provide new insights into the unique mechanisms responsible for NF-κB inhibition, in contrast to established immunosuppressants, as a therapeutic agent for immunopathological treatment.

Naïve CD8 T cell activation by liver bone marrow-derived cells leads to a "neglected" IL-2low Bimhigh phenotype, poor CTL function and cell death

BACKGROUND & AIMS

The occurrence of primary CD8 T cell activation within the liver, unique among the non-lymphoid organs, is now well accepted. However, the outcome of intrahepatic T cell activation remains controversial. We have previously reported that activation initiated by hepatocytes results in a tolerogenic phenotype characterized by low expression of CD25 and IL-2, poor cytotoxic T lymphocyte (CTL) function, and excessive expression of the pro-apoptotic protein Bim.

METHODS

To investigate whether this phenotype was due to activation in the absence of co-stimulation, we generated bone marrow (bm) radiation chimeras in which adoptively transferred naïve transgenic CD8 T cells were activated in the presence of co-stimulation by liver bm-derived cells.

RESULTS

Despite expressing pro-inflammatory cytokines, high levels of CD25 and CD54, donor T cells activated by liver bm-derived cells did not produce detectable IL-2 and displayed poor CTL function, suggesting incomplete acquisition of effector function. Simultaneously, these cells expressed high levels of Bim and died by neglect. Transfer of Bim-deficient T cells resulted in increased T cell numbers.

CONCLUSIONS

These results imply that expression of CD25 and CD54 is co-stimulation dependent and distinguishes T cell activated by hepatocytes and liver bm-derived cells. In contrast, low expression of IL-2, poor CTL function and excess Bim production represent a more universal phenotype defining T cells undergoing primary activation by both types of hepatic antigen presenting cells (APC). These results have important implications for transplantation, in which all liver antigen presenting cells contribute to activation of T cells specific for the allograft.

Immune mechanisms of Concanavalin A model of autoimmune hepatitis

As a chronic inflammatory disease of the liver, the pa-thogenic 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 elucidated 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.

Animal models for the study of liver fibrosis: new insights from knockout mouse models

Fibrosis arises as part of a would-healing response that maintains organ structure and integrity following tissue damage but also contributes to a variety of human pathologies such as liver fibrosis. Liver fibrosis is an abnormal response of the liver to persistent injury with the excessive accumulation of collagenous extracellular matrices. Currently there is no effective treatment, and many patients end up with a progressive form of the disease, eventually requiring a liver transplant. The clarification of mechanisms underlying pathogenesis of liver fibrosis and the development of effective therapy are of clinical importance. Experimental animal models, in particular targeted gene knockouts (loss of function) in mice, have become a powerful resource to address the molecular mechanisms or significance of the targeted gene in hepatic functions and diseases. This review will focus on the recent advances in knowledge obtained from genetically engineered mice that provide novel insights into the pathophysiology of liver fibrosis.

Anti-PDGF-B monoclonal antibody reduces liver fibrosis development

AIM

  To evaluate the usefulness of a platelet-derived growth factor (PDGF)-B specific monoclonal antibody (mAb) as a therapeutic agent to treat chronic liver fibrosis.

METHODS

  Liver fibrosis was induced in ICR mice by bile duct ligation (BDL) or BALB/c mice by weekly injection of concanavalin A (ConA) for 4 or 8 weeks. A mAb specific for mouse and human PDGF-B chain, AbyD3263, was generated, tested in vitro and administered twice a week throughout the experimental period.

RESULTS

  AbyD3263 showed neutralizing activity against mouse and human PDGF-B chain in cell-based assays, as measured in vitro by inhibition of phosphorylation of PDGF receptor β and proliferation of hepatic stellate cells induced by PDGF-BB. The half life of AbyD3263 in mice exceeded 7 days and dosing of animals twice a week resulted in constant plasma levels of the mAb. Induction of liver fibrosis by BDL and ConA resulted in elevated levels of alanine aminotransferase (ALT) in plasma and hydroxyproline in the liver. Treatment with AbyD3263 did not modify ALT levels, but significantly reduced hydroxyproline content in the liver with a maximum reduction of 39% and 54% in the BDL and ConA models, respectively, compared to controls. Conclusios:  Consistent with the notion that PDGF-BB plays an important role in the progression of liver fibrosis, AbyD3263 exhibits efficacy in pre-clinical disease models suggesting that pharmacological inhibition of PDGF-B chain may be a therapeutic approach to treat liver fibrosis.

Endogenous alpha-calcitonin gene-related peptide mitigates liver fibrosis in chronic hepatitis induced by repeated administration of concanavalin A

BACKGROUND

Alpha-calcitonin gene-related peptide (alphaCGRP) is a 37-amino acid pleiotropic peptide that we previously showed to exert a hepatoprotective effect during concanavalin A (Con A)-induced acute hepatitis. In the present study, we used alphaCGRP(-/-) mice to further investigate the antifibrogenic and hepatoprotective effects of endogenous alphaCGRP in Con A-induced chronic hepatitis.

METHODS

Chronic hepatitis was induced in alphaCGRP(-/-) and wild-type mice by repeated administration of Con A. Serum transaminases were measured to assess hepatic injury. The severity of fibrosis and the activation of hepatic stellate cells (HSCs) were analysed by Masson trichrome staining and immunohistochemical staining of alpha-smooth muscle actin (alpha-SMA) respectively. Altered expression of fibrosis- and inflammation-related genes was evaluated using a quantitative real-time polymerase chain reaction. Activation and proliferation of HSCs were analysed using both primary cultured HSCs from the mice and the LI90 HSC cell line.

RESULTS

alphaCGRP(-/-) mice showed more severe liver fibrosis than wild-type mice in a Con A-induced chronic hepatitis model. In histological and gene expression analyses, alphaCGRP(-/-) mice showed greater inflammatory and fibrotic changes, greater HSC activation and a higher incidence of apoptosis among nonparenchymal cells than wild-type mice.

CONCLUSIONS

Endogenous alphaCGRP mitigates liver fibrosis in chronic hepatitis induced by repeated administration of Con A. alphaCGRP could be a useful therapeutic target for the treatment of chronic hepatitis.

The importance of immune dysfunction in determining outcome in acute liver failure

Acute liver failure (ALF) shares striking similarities with septic shock with regard to the features of systemic inflammation, progression to multiple organ dysfunction and functional immunoparesis. While the existence of opposing systemic pro- and anti-inflammatory profiles resulting in organ failure and immune dysfunction are well recognised in septic shock, characterization of these processes in ALF has only recently been described. This review explores the evolution of the systemic inflammation in acute liver failure, its relation to disease progression, exacerbation of liver injury and development of innate immune dysfunction and extra-hepatic organ failure as sequelae. Defects in innate immunity are described in hepatic and extra-hepatic compartments. Clinical studies measuring levels of pro- and anti-inflammatory cytokines and expression of the antigen presentation molecule HLA-DR on monocytes, in combination with ex-vivo experiments, demonstrate that the persistence of a compensatory anti-inflammatory response syndrome, leading to functional monocyte deactivation, is a central event in the evolution of systemic immune dysfunction. Accurate immune profiling in ALF may permit the development of immunomodulatory strategies in order to improve outcome in this condition.

Liver fibrosis

Liver damage leads to an inflammatory response and to the activation and proliferation of mesenchymal cell populations within the liver which remodel the extracellular matrix as part of an orchestrated wound-healing response. Chronic damage results in a progressive accumulation of scarring proteins (fibrosis) that, with increasing severity, alters tissue structure and function, leading to cirrhosis and liver failure. Efforts to modulate the fibrogenesis process have focused on understanding the biology of the heterogeneous liver fibroblast populations. The fibroblasts are derived from sources within and out with the liver. Fibroblasts expressing alpha-smooth muscle actin (myofibroblasts) may be derived from the transdifferentiation of quiescent hepatic stellate cells. Other fibroblasts emerge from the portal tracts within the liver. At least a proportion of these cells in diseased liver originate from the bone marrow. In addition, fibrogenic fibroblasts may also be generated through liver epithelial (hepatocyte and biliary epithelial cell)-mesenchymal transition. Whatever their origin, it is clear that fibrogenic fibroblast activity is sensitive to (and may be active in) the cytokine and chemokine profiles of liver-resident leucocytes such as macrophages. They may also be a component driving the regeneration of tissue. Understanding the complex intercellular interactions regulating liver fibrogenesis is of increasing importance in view of predicted increases in chronic liver disease and the current paucity of effective therapies.

RNA interference targeting leptin gene effect on hepatic stellate cells

To construct the specific siRNA expression vectors and investigate their effect on leptin and collagen I in HSC, which provide a new approach to the prevent and treat hepatic fibrosis. The five siRNAs against leptin gene were transcript synthesized intracellularly by expression templates of plasmid vector psiRNA-hH1neo. The recombinant leptin siRNA plasmid vectors could express in eukaryocyte, and then to evaluate them by using enzyme cutting and sequencing. The recombinant plasmids were transfected into HSCs using Lipofectamine methods respectively. The cells were selected after growing in DMEM containing 300 microg/mL G418 for about 4 weeks. Gene expression of leptin and collagen I were showed by Western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). Identification by enzyme cutting and sequencing showed that the leptin siRNA expression vectors were constructed successfully, and leptin siRNA could inhibit the leptin and collagen I gene expression effectively. It was concluded that RNA interference-mediated silencing of leptin gene diminished leptin and collagen I gene expression in HSCs. Furthermore, attenuated the extracellular matrix over-deposition at the same time. Leptin gene is ideal targets of gene therapy for liver fibrosis.

Deficiency of tenascin-C attenuates liver fibrosis in immune-mediated chronic hepatitis in mice

Tenascin-C (TNC), an extracellular matrix glycoprotein, is upregulated in chronic liver disease. Here, we investigated the contribution of TNC to liver fibrogenesis by comparing immune-mediated hepatitis in wild-type (WT) and TNC-null (TNKO) mice. Eight-week-old BALB/c mice received weekly intravenous injections of concanavalin A to induce hepatitis, and were sacrificed one week after the 3rd, 6th, 9th, and 12th injections. In WT livers, immunohistochemical staining revealed a gradual increase in TNC deposition. TNC mRNA levels also increased sequentially and peaked after the 9th injection. Collagen deposition, stained with picrosirius red, was significantly less intense in TNKO mice than in WT mice, and procollagen I and III transcripts were significantly upregulated in WT mice compared with TNKO mice. Inflammatory infiltrates were most prominent after the 3rd-6th injections in both groups and were less intense in TNKO mice than in WT mice. Interferon-gamma, tumour necrosis factor-alpha, and interleukin-4 mRNA levels were significantly higher in WT mice than in TNKO mice, while activated hepatic stellate cells (HSCs) and myofibroblasts, a cellular source of TNC and procollagens, were more common in WT livers. Transforming growth factor (TGF)-beta1 mRNA expression was significantly upregulated in WT mice, but not in TNKO mice. In conclusion, TNC can promote liver fibrogenesis through enhancement of inflammatory response with cytokine upregulation, HSC recruitment, and TGF-beta expression during progression of hepatitis to fibrosis.

Research advances in the imbalance of helper T lymphocyte subpopulations and cytokine network in patients with chronic hepatitis B

Helper T (Th) lymphocytes, important immune regulating cells of organism, could be divided into four functional subsets, Th0, Th1, Th2, Th3, on the basis of the immunoregulatory cytokines that these clones produced. Most of the current work in this field is exploratory and focuses on Th1 and Th2 subsets. Th1 cells secrete interferon-γ (IFN-γ), interkeukin-2 (IL-2) and tumor necrosis factor-β and are principally involved in cell-mediated immunity. They play an important role in the protection against intracellular pathogens, including a variety of viruses. Th2 cells secret interleukin-4 (IL-4), IL-5, IL-6 and IL-10 and regulate the humoral immune response. Th0 cells are naive Th cells, secreting Th1/Th2 phenotype cytokines at low levels. However, Th3 cells, which secrete active transforming growth factor-β, exert a negative immunoregulatory action on the immune response. The cross-regulatory properties of Th1 and Th2 subset cells and relevant cytokines network are very important to maintain normal immunity of organisms. HBV can destroy the balance of Th lymphocytes and cytokines network. The imbalance of pro-inflammatory Th1 and anti-inflammatory Th2 cytokine production play an important role in the immunopathogenesis of hepatitis B virus infection and alter chronic liver disease development, progression and outcome.

IL-10, regulatory T cells, and Kupffer cells mediate tolerance in concanavalin A-induced liver injury in mice

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

CONCLUSION

The immunosuppressive cytokine IL-10 is crucial for tolerance induction in ConA hepatitis and is mainly expressed by CD4+CD25+ T(reg) and KC. Moreover, T(reg)s exhibit therapeutic potential against immune-mediated liver injury.

Concanavalin A induces autophagy in hepatoma cells and has a therapeutic effect in a murine in situ hepatoma model

Concanavalin A (ConA), a lectin with mannose specificity that can induce acute hepatic inflammation, was tested for its therapeutic effect against hepatoma. ConA is cytotoxic or inhibitory to hepatoma cells, which is mediated by the autophagic pathway through mitochondria. Once it was bound to cell membrane glycoproteins, the ConA was internalized and preferentially localized onto the mitochondria. The mitochondria membrane permeability changed, and an autophagic pathway including LC3-II generation, double-layer vesicle, BNIP3 induction, and acidic vesicular organelle formation was induced. Either 3-MA or siRNA for BNIP3 and LC3, but neither beclin-1 nor ATG 5, partially inhibited the ConA-induced cell death. In addition to the autophagy induction, ConA is known to be a T cell mitogen. Using an in situ hepatoma model, ConA can exert an anti-hepatoma therapeutic effect, inhibiting tumor nodule formation in the liver and prolonging survival.

CONCLUSION

ConA can be considered as an anti-hepatoma agent therapeutically because of its autophagic induction and immunomodulating activity. This dual function of ConA provides a novel mechanism for the biological effect of lectin.

Clone culture of human interleukin-10 gene modified L02 hepatocytes and selection of cell strain with most interleukin-10 expression

AIM: To clone and culture human interleukin-10 (IL-10) gene modified L02 hepatocytes and select the cell strain highly expressing IL-10.

METHODS: With preparation of previously constructed and purified eukaryotic expression plasmid vector pchIL-10, L02 hepatocytes were transfected and then the positive clones were selected with the help of G418 pressure. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of human IL-10 in the cells strain.

RESULTS: Sequencing and restriction endonuclease digestion confirmed that eukaryotic expression plasmid vector pchIL-10 was constructed successfully, and electrophoresis show a band of 540 bp. hIL-10 gene was highly expressed in L02 hepatocytes and the highest expression level was 69.875 ng/10⁶ cell per hour.

CONCLUSION: Human interleukin-10 (IL-10) gene modified L02 hepatocytes can highly expresses hIl-10, which may be used in the antifibrotic or cirrhotic treatment.

Interleukin-10 and chronic liver disease

Interleukin (IL)-10 is an important immunoregulatory cytokine produced by many cell populations. Numerous investigations suggest that IL-10 plays a major role in chronic liver diseases. IL-10 gene polymorphisms are possibly associated with liver disease susceptibility or severity. Recombinant human IL-10 has been produced and is currently tested in clinical trials. These trials may give new insights into the immunobiology of IL-10 and suggest that the IL-10/IL-10 receptor system may become a new therapeutic target.

Pre-activation of T lymphocytes by low dose of concanavalin A aggravates toll-like receptor-3 ligand-induced NK cell-mediated liver injury

Concanavalin A (Con A), a widely used murine T cell stimulator, could induce T cell-mediated hepatitis when used in an abundant dosage. However, the immune-modulating role of non-hepatotoxic dosage of Con A in hepatic immune responses remains obscure. In order to evaluate the effect of non-hepatotoxic Con A on hepatic NK cells, pretreatment of mice with low dose of Con A was performed on polyinosinic-polycytidylic acid (poly I:C) [toll-like receptor-3 (TLR-3) ligand]-induced NK cell-mediated hepatitis. The role of the Con A-pre-activated T cells in NK cell function was then determined. The results demonstrated that Con A pretreatment aggravated poly I:C-induced liver injury with elevation of serum transaminases, hepatic necrosis and serum IFN-gamma level. In parallel to the enhanced accumulation of activated NK cells into liver, the natural cytotoxicity and IFN-gamma production by hepatic NK cells were significantly augmented. Moreover, depletion of T cells suppressed the aggravating effect of Con A pretreatment. Collectively, the aggravation of poly I:C-induced hepatitis by Con A pretreatment may be due to the generation of more vigorous NK cells which is dependent on the presence of T cells. This investigation will help to explain the synergistic effects of NK and T cells in liver inflammatory injury.

Effects of adrenomedullin gene overexpression on biological behavior of hepatic stellate cells

AIM: To investigate the effects of adrenomedullin (AM) gene overexpression on the biological characteristics of human hepatic stellate cells (hHSCs) by stable transfection.

METHODS: hHSCs which express low basal levels of AM were stably transfected with an expression construct containing rat AM gene or with an empty expression vector. Expression of AM in hHSCs was determined by reverse transcription (RT)-polymerase chain reaction (PCR) and radioimmunoassay (RIA). Cell proliferation was evaluated by 5-bromo-2’-deoxyuridine (BrdU) incorporation and immunocytochemistry. RT-PCR and Western blot were used to test the expression of procollagen types I and III. Protein expressions of interstitial collagenase (MMP-1), gelatinase (MMP-2) and tissue inhibitors of matrix metalloproteinases-2 (TIMP-2) were assessed by Western blot.

RESULTS: Two cell clones (A-2, A-8) transfected with the AM gene expressed higher levels of AM mRNA (non-transfected group: 0.86±0.11, empty vector group: 1.01±0.11, A-2 clone group: 1.44±0.08 and A-8 clone group: 1.36±0.05) and protein (12.31±0.17, 12.35±0.12, 12.56±0.06 and 12.62±0.07) (P<0.05). AM gene overexpression had inhibitory effects on cell proliferation of hHSCs (29.6%, 30.9%, 18.9% and 21.8%, respectively. P<0.05) and expression of procollagen type I (0.58±0.1, 0.48±0.11, 0.3±0.06 and 0.31±0.07 at mRNA level) (0.27±0.07, 0.3±0.06, 0.14±0.05 and 0.13±0.05 at protein level) (P<0.05) and procollagen type III (0.17±0.04, 0.15±0.03, 0.1±0.02 and 0.09±0.02 at mRNA level) (0.22±0.04, 0.2±0.03, 0.11±0.04 and 0.13±0.03 at protein level) (P<0.05). Compared with cells non-transfected (TIMP2: 2.77±0.03, MMP-2: 0.5±0.04, MMP-1: 0.49±0.07) and transfected with empty vector (TIMP2: 2.79±0.04, MMP-2: 0.48±0.03, MMP-1: 0.45±0.09), these two clones had lower expression levels of TIMP2(A-2 clone group: 2.7±0.02 and A-8 clone group: 2.71±0.02) (P<0.05) and MMP-2(A-2 clone group: 0.15±0.05 and A-8 clone group: 0.13±0.04) (P<0.05) but displayed a higher expression level of MMP-1(A-2 clone group: 0.68±0.06 and A-8 clone group: 0.81±0.09) (P<0.05).

CONCLUSION: AM gene exerts negative influence to some extent on hHSCs by inhibiting proliferation and production of extracellular matrix (ECM) in addition to inducing MMP-1 expression.

Effects of augmentation of liver regeneration recombinant plasmid on rat hepatic fibrosis

AIM

To investigate the effects of eukaryotic expression of plasmid on augmentation of liver regeneration (ALR) in rat hepatic fibrosis and to explore their mechanisms.

METHODS

Ten rats were randomly selected from 50 Wistar rats as normal control group. The rest were administered intraperitoneally with porcine serum twice weekly. After 8 wk, they were randomly divided into: model control group, colchicine group (Col), first ALR group (ALR1), second ALR group (ALR2). Then colchicine ALR recombinant plasmid were used to treat them respectively. At the end of the 4th wk, rats were killed. Serum indicators were detected and histopathological changes were graded. Expression of type I, III, collagen and TIMP-1 were detected by immunohistochemistry and expression of TIMP-1 mRNA was detected by semi-quantified RT-PCR.

RESULTS

The histologic examination showed that the degree of the rat hepatic fibrosis in two ALR groups was lower than those in model control group. Compared with model group, ALR significantly reduced the serum levels of ALT, AST, HA, LN, PCIII and IV (P<0.05). Immunohistochemical staining showed that expression of type I, III, collagen and TIMP-1 in two ALR groups was ameliorated dramatically compared with model group (I collagen: 6.94+/-1.42, 5.80+/-1.66 and 10.83+/-3.58 in ALR1, ALR2 and model groups, respectively; III collagen: 7.18+/-1.95, 4.50+/-1.67 and 10.25+/-2.61, respectively; TIMP-1: 0.39+/-0.05, 0.20+/-0.06 and 0.53+/-0.12, respectively, P<0.05 or P<0.01). The expression level of TIMP-1 mRNA in the liver tissues was markedly decreased in two ALR groups compared with model group (TIMP-1 mRNA/beta-actin: 0.89+/-0.08, 0.65+/-0.11 and 1.36+/-0.11 in ALR1, ALR2 and model groups respectively, P<0.01).

CONCLUSION

ALR recombinant plasmid has beneficial effects on rat hepatic fibrosis by enhancing regeneration of injured liver cells and inhibiting TIMP-1 expressions.

A novel therapy for acute hepatitis utilizing dehydroepiandrosterone in the murine model of hepatitis

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

Characterization of the Effect of Interleukin-10 on Silica-Induced Lung Fibrosis in Mice

We previously described a reduction of silica-induced lung fibrosis in interleukin-10-deficient mice (IL-10-/-) (Huaux and colleagues; Am. J. Respir. Cell Mol. Biol. 1998;18:51-59). In the present study, we further dissect the exact functions of IL-10 in experimental silicosis. The reduced lung fibrotic response to silica in IL-10-/- mice was accompanied by a marked recruitment of TH1 CD4+ lymphocytes. However, treatment with anti-CD4 antibodies reduced silica-induced lung fibrosis in both IL-10-/- and IL-10+/+ mice, suggesting that this T cell population actually contributes to the extension of the fibrotic lesions in a manner that is independent of IL-10. In IL-10-/- mice, silica-induced lung production of the profibrotic mediator transforming growth factor (TGF)-beta1 and the antifibrotic eicosanoid PGE2 were reduced and increased, respectively, relative to that in IL-10+/+ mice. In addition, in vitro experiments indicated that recombinant IL-10 upregulated TGF-beta1 expression in alveolar macrophages while in contrast it downregulated PGE2 production and cyclooxygenase-2 expression in both lung fibroblasts and macrophages. Thus the net profibrotic activity of IL-10 in vivo appears to be mediated by its ability to stimulate the expression of the profibrotic cytokine TGF-beta1 while suppressing the expression of cyclooxygenase-2 and thus production of the antifibrotic eicosanoid PGE2. These effects appear to be independent of the enhanced lung CD4+ T-lymphocytosis observed in IL-10-deficient mice.

Intracellular regulation of Fas-induced apoptosis in human fibroblasts by extracellular factors and cycloheximide

Fibroblasts play an important role in reparative and inflammatory processes by synthesizing extracellular matrix components and releasing growth factors and cytokines. Fibroblast apoptosis has been observed at the termination phase of reparative or fibrotic responses, but its regulation in this context is poorly known. We investigated the susceptibility of human dermal fibroblasts (DF) to Fas-induced apoptosis and its regulation by extracellular factors potentially involved in immune-mediated inflammation and repair. DF expressed all components of the Fas apoptotic pathway: surface Fas, Fas-associated protein with death domain, and caspase-8 proteins. However, Fas activation resulted in caspase-8 activation and apoptosis only in the presence of cycloheximide (CHX). DF constitutively expressed Fas-associated death domain-like IL-1-converting enzyme-like inhibitory protein (FLIP) that was drastically down-regulated by CHX. Exogenous growth factors, cytokines, and adherence to the extracellular matrix shifted the balance of FLIP-caspase-8 proteins and modified the susceptibility of DF to Fas- or Fas-CHX-induced apoptosis. Short-term serum deprivation, suspension culture, and pretreatment with IFN-gamma or TNF-alpha increased, whereas long-term serum-free culture and pretreatment with TGF-beta or IL-10 decreased the apoptotic susceptibility of DF. Surface Fas expression was only modified by TNF-alpha and IFN-gamma, whereas all studied factors modified FLIP-caspase-8 protein expression, consistently with their pro- or antiapoptotic effects. Antisense FLIP oligonucleotides prevented resistance to Fas-induced apoptosis in DF. FLIP-caspase-8 balance seems tightly regulated in fibroblasts by extracellular factors that determine their susceptibility to Fas- or Fas-CHX-induced apoptosis. Th1 and Th regulatory cytokines display opposite effects on fibroblast apoptosis that suggest that their pro- or antifibrotic effects involve direct effects on fibroblast survival.

Expression of insulin-like growth factor 1 and insulin-like growth factor 1 receptor and its intervention by interleukin-10 in experimental hepatic fibrosis

AIM

To study the expression of IGF-1 and IGF-1R and its intervention by interleukin-10 in the course of experimental hepatic fibrosis.

METHODS

Hepatic fibrosis was induced in rats by carbon tetrachloride intoxication and liver specimens were taken from the rats administered CCl4 with or without IL-10 treatment and the animals of the control group. Immunoreactivities for insulin-like growth factor-1 (IGF-1) and IGF-1 receptor(IGF-1R) were demonstrated by immunohistochemistry, and their intensities were evaluated in different animal groups.

RESULTS

The positive levels for IGF-1 and IGF-1R were increased with the development of hepatic fibrosis, with the positive signals localized in cytoplasm and/or at the plasmic membrane of hepatocytes. The positive signals of IGF-1 and IGF-1R were observed more frequently (P<0.01) in the CCl4-treated group (92.0 % and 90.0 %) compared to those in the control group. The positive signals decreased significantly (P<0.05) in IL-10-treated group. The responses in IGF-1 and IGF-1R expression correlated with the time of IL-10 treatment.

CONCLUSION

The expression of IGF-1 and IGF-1R immunoreactivities in liver tissue seems to be up-regulated during development of hepatic fibrosis induced by CCl(4), and exogenic IL-10 inhibits the responses.

Inhibition on the production of collagen type I, III of activated hepatic stellate cells by antisense TIMP-1 recombinant plasmid

AIM

To investigate the inhibition effects on the production of collagen type I, III secreted by activated rat hepatic stellate cells (rHSCs) by antisense tissue inhibitors of metalloproteinase 1 (TIMP-1) recombinant plasmid through elevating interstitial collagenase activity.

METHODS

rHSCs were extracted from normal rat liver by pronase and collagenase digestion and purified by centrifugal elutriation, and were cultured on plastic dishes until they were activated to a myofibroblastic phenotype after 7-10 days. RT-Nest-PCR and gene recombinant techniques were used to construct the rat antisense TIMP-1 recombinant plasmids which can express in eucaryotic cells. The recombinant plasmid and the pcDNA3 empty plasmid were transfected in rHSCs by Effectene (QIAGEN) separately. Cells were selected after growing in DMEM containing 400 microg/ml G418 for 2-3 weeks. Expression of exogenous gene was assessed by Northern blot, and expression of TIMP-1 in rHSCs was determined by Northern blot and Western blot. We tested the interstitial collagenase activity with FITC-labled type I collagen as substrate. Ultimately, we quantified the type I, III collagen by Western blot.

RESULTS

The exogenous antisense TIMP-1 recombinant plasmid could be expressed in rHSCs well, which could block the expression of TIMP-1 greatly, the ratio of TIMP-1/GAPDH was 0.67, 2.41, and 2.97 separately at mRNA level (P<0.05); the ratio of TIMP-1/beta-actin was 0.31, 0.98 and 1.32 separately at protein level (P<0.05); It might elevate active and latent interstitial collagenase activity, the collagenase activity was 0.3049, 0.1411 and 0.1196 respectively. (P<0.05), which led to promotion the degradation of type I, III collagen, the ratio of collagen I/beta-actin was 0.63, 1.78 and 1.92 separately (P<0.05); and the ratio of collagen III/beta-actin was 0.59, 1.81 and 1.98 separately (P<0.05).

CONCLUSION

These data shows that the antisense TIMP-1 recombinant plasmid has the inhibitory effects on the production of type I, III collagens secreted by activated rHSCs in vitro. It could be a novel method to reverse hepatic fibrosis in the future.

Novel murine autoimmune-mediated liver disease model induced by graft-versus-host reaction and concanavalin A

BACKGROUND AND AIMS

We have previously reported that cluster of differentiation (CD)4+ T cells induced autoimmune liver diseases in mice with graft-versus-host reaction (GVHR) because of major histocompatibility complex (MHC) class II disparity. To analyze the progression of the autoimmune-related mechanism in the liver, concanavalin A (Con A) was injected in mice undergoing GVHR. The aim of this study is to clarify whether Con A deteriorates murine hepatic lesions induced by GVHR, and to elucidate the participation of the cytokines of liver-infiltrating CD4+ T cells.

METHODS

Mice (F1; B6.C-H-2(bm12) x B6) were intravenously injected with B6 T spleen cells. Concanavalin A (15 mg/kg) was administrated 5 days after cell transfer. We examined serum transaminase, antimitochondrial antibodies (AMA), antinuclear antibodies (ANA) and histological changes. Liver-infiltrating CD4+ T cells were sorted and their cytokine mRNA expression was examined by the use of reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Graft-versus-host reaction + Con A mice revealed an elevated serum transaminase, elevated AMA and ANA titers, increased periportal cellular infiltration, piecemeal necrosis and bridging necrosis in the liver. In this group, interferon (IFN)-gamma mRNA expression was more elevated than it was in the GVHR mice. However, there was no difference in the expression of interleukin (IL)-10 mRNA between the two groups.

CONCLUSION

The results suggest that Con A deteriorates the GVHR-induced hepatic lesions, and IFN-gamma and IL-10 of CD4+ T cells might be implicated in the progression of autoimmune-related hepatic lesions. This model might offer an aspect for the investigation of progressive mechanisms in T-cell- mediated hepatobiliary injury.

Serum levels of interleukin-6 and interleukin-10 correlate with total skin thickness score in patients with systemic sclerosis

Various growth factors and cytokines have been suggested to play a central role in initiating and developing fibrosis in systemic sclerosis (SSc). To determine which serum levels of soluble mediators are the most relevant to the degree of skin sclerosis in SSc, serum levels of various soluble mediators were examined by ELISA and correlated with skin thickening that was measured using modified Rodnan total skin thickness scoring (TSS) system. Serum levels of IL-4, IL-12, IL-13, tumor necrosis factor-alpha, connective tissue growth factor (CTGF), vascular endothelial growth factor, monocyte chemotactic protein-1, macrophage inflammatory protein-1beta, soluble IL-6 receptor, and soluble L-selectin were higher in SSc patients than normal controls. Levels of IL-6, IL-10, and CTGF in patients with diffuse cutaneous SSc were higher than patients with limited cutaneous SSc and controls. Serum levels of IL-6 and IL-10 positively correlated with TSS in patients with SSc (r=0.625, P<0.0001 and r=0.663, P<0.0001, respectively). In addition, IL-10 levels significantly correlated with pulmonary fibrosis. Thus, serum levels of IL-6 and IL-10 most strongly reflect the extent of skin thickening in SSc, suggesting that levels of IL-6 and IL-10 are useful serological indicators for skin fibrosis in SSc.

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM

To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed.

METHODS

Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination.

RESULTS

Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P> 0.05).

CONCLUSION

The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

Inhibition of hepatic stellate cell proliferation and activation by the semisynthetic analogue of fumagillin TNP-470 in rats

Proliferation and activation of hepatic stellate cells (HSCs) are critical steps for the development of postnecrotic fibrosis in the liver. The present study aimed to reveal the inhibitory effect of the semisynthetic analogue of fumagillin TNP-470 on these events for its possible use as an antifibrogenic agent. Rat models of carbon tetrachloride (CCl(4))- and dimethylnitrosamine-induced hepatic fibrosis were used for an in vivo study. In both models, the fibrotic area was considerably decreased by concurrent repetitive subcutaneous injections of 30 mg/kg body weight of TNP-470. In CCl(4)-induced fibrosis, factor VIII-related antigen-positive blood vessels, desmin-, or alpha-smooth muscle actin (alphaSMA)-positive mesenchymal cells, bromodeoxyuridine (BrdU)-positive mesenchymal cells also decreased in number by treatment with TNP-470. In in vitro experiments, a supplement of 1,000 ng/mL TNP-470 suppressed BrdU incorporation and cyclins D1, D2, and E expression by cultured HSCs in the absence and/or presence of platelet-derived growth factor (PDGF). Expression of HSC activation markers, i.e., alphaSMA and PDGF receptor beta, was also suppressed. The present results indicate that TNP-470 inhibits HSC proliferation by blocking the cell-cycle transition from G1 to S and HSC activation, and, as the consequence, prevents the progression of hepatic fibrosis, probably being coupled with its antiangiogenic effect.