Inhibitory effects of nodakenin on inflammation and cell death in lipopolysaccharide-induced liver injury mice

BACKGROUND

Nodakenin, a coumarin glucoside isolated from the roots of Angelica biserrata, has been reported to have anti-inflammatory, antibacterial, anticancer effects. However, despite these studies, the potential liver protective effects of nodakenin in inflammatory liver injury models have not been reported.

METHODS

A mouse model of inflammatory liver injury was induced by injection of lipopolysaccharide (LPS) (15 mg/kg, intraperitoneally (i.p)). Liver tissue AST, ALT, ROS, T-GSH and T-SOD were analyzed by ELISA. The concentrations of TNF-α, IL-6, and IL-1β in serum of LPS-induced inflammatory liver injury mice were analyzed. The mRNA expression levels of GPx1, catalase, SOD1, SOD2, TNF-α, IL-6, IL-1β, iNOS and COX-2 were analyzed using real-time PCR. The expressions of MAPK, IRF3, NF-κB, Nrf2, HO-1, caspase-3 and caspase-7 were analyzed using western blotting. Liver tissue was stained with IHC to confirm NF-κB, Nrf-2, HO-1, caspase-3, Bax, and Bcl2. Tunnel analysis was performed to confirm the fragmented nuclear DNA characteristics of apoptosis.

RESULTS

The administration of nodakenin (10 and 30 mg/kg) reduced serum aminotransferase levels compared to LPS-induced liver damage and significantly improved the oxidative state of liver tissue and pathological damage. Moreover, inhibited the phosphorylation of transforming growth factor beta (TGF-β)-activated kinase (TAK)-1 in LPS-induced inflammatory liver injury model, and significantly inhibited the transcriptional of nuclear factor-kappa B (NF-kB) and the secretion of pro-inflammatory mediators. In addition nodakenin pre-treatment also attenuated hepatocyte death by regulating apoptosis-related mitochondrial proteins, such as cysteinyl aspartate specific proteinase 3 (caspase 3), poly (ADP-ribose) polymerase (PARP), B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax).

CONCLUSION

Our findings suggest that nodakenin has anti-inflammatory, anti-oxidant and anti-apoptotic activity and may be an adjunctive prevention agent for liver injury.

Evaluation of metallothionein and Ki-67 expression in chronic cholangiohepatitis in cats

Chronic cholangiohepatitis (CCH) is a common pathological condition in cats with a guarded prognosis and unknown etiology. Recently, in human medicine, there has been increased interest in enhancing liver defense mechanisms as an effective treatment strategy to control liver diseases that have a poor prognosis. Metallothionein (MT) is a ubiquitous protein, which has been widely researched for its role in liver defense through heavy metal detoxification, neutralization of reactive oxygen species, and liver regeneration. In this study, immunohistochemistry was used to evaluate the role of MT in CCH and hepatocellular regeneration in 34 cats histologically diagnosed with this condition by assessing the correlation between hepatocellular MT and Ki-67 (marker for cellular proliferation) expression with histological parameters of CCH, such as inflammation, fibrosis, and bile duct proliferation. Statistical analysis was performed using the Spearman-rank correlation test. A significant positive correlation was observed between inflammation and the number of MT-positive hepatocytes (r = 0.36, P = 0.03) and MT labelling intensity (r = 0.37, P = 0.03). In 16 of 34 cases (47%) MT labelling intensity was noted to be pronounced towards the centrilobular zone and very weak or absent towards the portal zone. The results suggest that MT is induced in the liver during chronic inflammatory conditions, which could be speculated as a host defensive mechanism to protect the liver from inflammation-mediated liver injury. Therapeutic interventions utilizing MT, therefore, may have a positive effect on cats with chronic cholangiohepatitis.

The role of the sphingosine axis in immune regulation: A dichotomy in the anti-inflammatory effects between sphingosine kinase 1 and sphingosine kinase 2-dependent pathways

Background: Sphingosine kinase has been identified as playing a central role in the immune cascade, being a common mediator in the cellular response to a variety of signals. The different effects of sphingosine kinase 1 and 2 (SphK1 and SphK2, respectively) activity have not been completely characterized. Aim: To determine the different roles played by SphK1 and SphK2 in the regulation of immune-mediated disorders. Methods: Nine groups of mice were studied. Concanavalin A (ConA) injection was used to induce immune-mediated hepatitis. Mice were treated with SphK1 inhibitor (termed SphK-I) and SphK2 inhibitor (termed ABC294640), prior to ConA injection, and effects of treatment on liver enzymes, subsets of T lymphocytes, and serum levels of cytokines were observed. Results: While liver enzyme elevation was ameliorated by administration of SphK1 inhibitor, SphK2 inhibitor-treated mice did not show this tendency. A marked decrease in expression of CD25+ T-cells and Foxp+ T-cells was observed in mice treated with a high dose of SphK1 inhibitor. Alleviation of liver damage was associated with a statistically significant reduction of serum IFNγ levels in mice treated with SphK1 inhibitor and not in those treated with SphK2 inhibitor. Conclusions: Early administration of SphK1 inhibitor in a murine model of immune-mediated hepatitis alleviated liver damage and inflammation with a statistically significant reduction in IFN-γ levels. The data support a dichotomy in the anti-inflammatory effects of SphK1 and SphK2, and suggests that isoenzyme-directed therapies can improve the effect of targeting these pathways.

Physalis peruviana L. Pulp Prevents Liver Inflammation and Insulin Resistance in Skeletal Muscles of Diet-Induced Obese Mice

A chronic high-fat diet (HFD) produces obesity, leading to pathological consequences in the liver and skeletal muscle. The fat in the liver leads to accumulation of a large number of intrahepatic lipid droplets (LD), which are susceptible to oxidation. Obesity also affects skeletal muscle, increasing LD and producing insulin signaling impairment. Physalis peruviana L. (PP) (Solanaceae) is rich in peruvioses and has high antioxidant activity. We assessed the ability of PP to enhance insulin-dependent glucose uptake in skeletal muscle and the capacity to prevent both inflammation and lipoperoxidation in the liver of diet-induced obese mice. Male C57BL/6J mice were divided into groups and fed for eight weeks: control diet (C; 10% fat, 20% protein, 70% carbohydrates); C + PP (300 mg/kg/day); HFD (60% fat, 20% protein, 20% carbohydrates); and HFD + PP. Results suggest that PP reduces the intracellular lipoperoxidation level and the size of LD in both isolated hepatocytes and skeletal muscle fibers. PP also promotes insulin-dependent skeletal muscle glucose uptake. In conclusion, daily consumption of 300 mg/kg of fresh pulp of PP could be a novel strategy to prevent the hepatic lipoperoxidation and insulin resistance induced by obesity.

Abatacept induced granulomatous hepatitis with a sarcoidosis- like reaction: a blinded trial in mice

BACKGROUND

Abatacept is increasingly used for rheumatoid arthritis (RA) and juvenile idiophathic arthritis (JIA) treatment. However little is known about the risk of hepatotoxicity. The aim of this study was to determine whether the inhibition of the T cell CD28 receptor by abatacept results in acute hepatitis in BALB/c mice.

METHODS

Twenty BALB/c mice were studied. Ten mice received subcutaneous (SC) injection of abatacept (0.25mg per 25g body weight per 0.03 ml normal saline) at 0, 2, 4 and 8 weeks. For the control group, 10 mice received a SC injection of normal saline (NS) (0.03 ml). At the 10th week post injection, the mice were sacrificed, and histopathological studies were conducted.

RESULTS

Of the abatacept-treated group, 3/10 mice died. Liver histology for the abatacept-treated group showed that 6/7 displayed histopathological changes in the lobular cellular infiltrates of eosinophils, lymphocytes and histiocytes, in addition to granuloma formation. In contrast, only minimal inflammation was observed in 3/10 mice in the control group (p=0.036).

CONCLUSION

Abatacept may play a role in inducing granulomatous hepatitis with a sarcoidosis-like reaction. Additional data including transaminases, antinuclear antibodies (ANA), Antimitochondrial antibodies (AMA) and other auto antibodies should be tested.

Hepatocyte expression and prognostic importance of senescence marker p21 in liver histopathology samples from dogs with chronic hepatitis

BACKGROUND

Chronic hepatitis (CH) occurs commonly in dogs but is associated with a variable and largely unpredictable prognosis. p21, a cell-cycle inhibitor and marker of cellular senescence, is upregulated in human liver disease and is a better prognostic marker than histological or clinical scoring systems.

OBJECTIVE

To quantify hepatocyte p21 immunopositivity in histopathology samples from dogs with CH and determine its association with outcome.

ANIMALS

Twenty-six client-owned dogs with histologically confirmed CH, and 15 dogs with normal liver histology.

METHODS

Medical records and liver histopathology samples were retrospectively reviewed to identify cases of CH. Immunohistochemistry for p21 was performed on all samples and hepatocyte immunopositivity was visually quantified. Relationships between p21 and dog age and dog survival time were statistically evaluated.

RESULTS

Hepatocyte p21 immunopositivity in dogs with CH was high (median percentage of positive hepatocytes: 90%, range: 20%-98%) and exceeded 70% in 23/26 cases with no association with age. In control dogs, p21 immunopositivity was low (≤15% positive hepatocytes in 12/15 cases) and was positively correlated with age (rs  = 0.63; P = .011). Dogs with p21 immunopositivity exceeding 91.8% (upper tercile) had significantly shorter survival compared to dogs with less than 88.9% immunopositivity (lowest tercile; 218 versus 874 days, P = .006). Increasing hepatocyte p21 immunopositivity was significantly negatively associated with survival time (HR 4.12; 95% CI 1.34-12.63; P = .013).

CONCLUSIONS AND CLINICAL IMPORTANCE

Marked p21 immunopositivity in dogs with CH might be indicative of widespread hepatocellular senescence. A significant association with survival time also suggests a potential value for p21 quantification in determining prognosis.

Treatment effect of a flavonoid prescription on duck virus hepatitis by its hepatoprotective and antioxidative ability

CONTEXT

Duck virus hepatitis (DVH) caused by duck hepatitis A virus type 1 (DHAV-1) is an acute and lethal disease of young ducklings. However, there is still no effective drug to treat DVH.

OBJECTIVE

This study assessed the curative effect on DVH of a flavonoid prescription baicalin-linarin-icariin-notoginsenoside R1 (BLIN) as well as the hepatoprotective and antioxidative effects of BLIN.

MATERIALS AND METHODS

MTT method was used to test the anti-DHAV-1 ability of BLIN in vitro. We then treated ducklings by BLIN (3 mg per duckling, once a day for 5 days) to evaluate the in vivo efficacy. To study the hepatoprotective and antioxidative roles of BLIN in its curative effect on DVH, we investigated the hepatic injury evaluation biomarkers and the oxidative stress evaluation indices of the ducklings.

RESULTS

On duck embryonic hepatocytes, DHAV-1 inhibitory rate of BLIN at 20 μg/mL was 69.3%. The survival rate of ducklings treated by BLIN was about 35.5%, which was significantly higher than that of virus control (0.0%). After the treatment of BLIN, both the hepatic injury and the oxidative stress of infected ducklings alleviated. At the same time, a significant positive correlation (p < 0.05) existed between the hepatic injury indices and the oxidative stress indices.

CONCLUSIONS

BLIN showed a significant curative effect on DVH. The antioxidative and hepatoprotective effects of BLIN made great contributions to the treatment of DVH. Furthermore, BLIN is expected to be exploited as a new drug for the clinical treatment of DVH.

Copper-associated Chronic Hepatitis and Cirrhosis in a European Shorthair Cat

A 2-year-old, castrated, male European Shorthair cat was presented with inappetence, vomiting, and fever. Ascites and an irregularly nodular liver were observed on laparotomy; in view of the poor prognosis, the animal was euthanatized. Histopathologic examination of the liver showed a chronic hepatitis with cirrhosis associated with massive accumulation of copper in hepatocytes and macrophages, particularly in the fibrotic areas between the regenerative nodules. Electron microscopy and energy-dispersive X-ray analysis revealed lysosomal accumulation of copper in the hepatocytes. Analytical determination showed very high copper concentrations in the liver. No evidence for increased dietary or environmental copper could be found. This and the pattern of hepatic copper storage, the associated inflammation and fibrosis, strongly suggest a primary copper storage disorder.

A Multistep Approach in the Cytologic Evaluation of Liver Biopsy Samples of Dogs with Hepatic Diseases

Cytologic criteria were evaluated for their diagnostic value in liver disease in dogs. Therefore, histopathologic and cytologic examination was performed on liver biopsy samples of 73 dogs with liver diseases and 28 healthy dogs. Logistic regression analysis was used to select the measured parameters to be included in a multistep approach. With the logistic regression method, different characteristic cytologic parameters could be defined for each histopathologic diagnosis. In malignant lymphoma of the liver, the presence of large numbers of lymphoblasts with a minimum of 5% of all cells was found. Clusters of epithelial cells with several cytologic characteristics of malignancy intermixed with normal hepatocytes were indicative of metastatic carcinoma or cholangiocellular carcinoma. Liver cells in hepatocellular carcinoma were characterized by a high nucleus/cytoplasm ratio, large cell diameters, increased numbers of nucleoli per nuclei, small numbers of cytoplasmic vacuoles, and frequently, small numbers of lymphocytes. Extrahepatic cholestasis was characterized by excessive extracellular bile pigment in the form of biliary casts, an increased number of nucleoli within hepatocytes, decreased hepatic cell size, and low numbers of lymphocytes. In destructive cholangiolitis, increased numbers of neutrophils and a small mean nuclear size within hepatocytes were seen. Acute and nonspecific reactive hepatitis are diagnosed based on the presence of moderate reactive nuclear patterns, including more pronounced chromatin, prominent nucleoli, increased numbers of inflammatory cells, excluding lymphocytes, and the absence of increased numbers of bile duct cell clusters. Increased number of mast cells also was indicative of nonspecific reactive hepatitis. Important cytologic criteria for the diagnosis of liver cirrhosis, in addition to chronic hepatitis, are intracellular bile accumulation and increased numbers of bile duct cell clusters. In summary, the stepwise approach based on logistic regression presented in this study might be helpful in the objective cytologic diagnosis of hepatic diseases.

Eosinophilic Granulomatous Gastroenterocolitis and Hepatitis in a 1-year-old Male Siberian Husky

A case of eosinophilic granulomatous gastroenterocolitis and hepatitis in a 1-year-old male Siberian Husky is described. The dog presented with a history of diarrhea, weakness, lethargy, and anorexia of several months' duration. Hematologic and biochemical examinations, abdominal ultrasonography, computer tomography, and exploratory laparotomy were performed. Histopathologic examination of full-thickness biopsies from the gastrointestinal tract and liver revealed the presence of eosinophilic granulomatous lesions in the submucosa and tunica muscularis of stomach, jejunum, ileum, colon, and liver. infectious agents were not detected by light microscopic and electron microscopic examination or by immunohistochemistry. On the basis of the findings, it is concluded that the disease in this dog represents an unusual manifestation of chronic idiopathic inflammatory bowel disease.

Presence of Systemic Inflammatory Response Syndrome Predicts a Poor Clinical Outcome in Dogs with a Primary Hepatitis

Primary hepatopathies are a common cause of morbidity and mortality in dogs. The underlying aetiology of most cases of canine hepatitis is unknown. Consequently, treatments are typically palliative and it is difficult to provide accurate prognostic information to owners. In human hepatology there is accumulating data which indicates that the presence of systemic inflammatory response syndrome (SIRS) is a common and debilitating event in patients with liver diseases. For example, the presence of SIRS has been linked to the development of complications such as hepatic encephalopathy (HE) and is associated with a poor clinical outcome in humans with liver diseases. In contrast, the relationship between SIRS and clinical outcome in dogs with a primary hepatitis is unknown. Seventy dogs with histologically confirmed primary hepatitis were enrolled into the study. Additional clinical and clinicopathological information including respiratory rate, heart rate, temperature, white blood cell count, sodium, potassium, sex, presence of ascites, HE score, alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin and red blood cell concentration were available in all cases. The median survival of dogs with a SIRS score of 0 or 1 (SIRS low) was 231 days compared to a median survival of 7 days for dogs with a SIRS score of 2, 3 or 4 (SIRS high) (p<0.001). A Cox proportional hazard model, which included all other co-variables, revealed that a SIRS high score was an independent predictor of a poor clinical outcome. The effect of modulating inflammation on treatment outcomes in dogs with a primary hepatitis is deserving of further study.

MORPHOLOGICAL CHANGES IN MICE LIVER IN DYNAMICS OF CONCANAVALIN A - INDUCED HEPATITIS

The injure of the liver tissue and its infiltration by cells of the innate and adaptive immunity in dynamics of Con A-induced hepatitis in mice was studied. The semiquantitative method of damage rate of microcirculation channel and liver parenchyma was used, leukocyte liver infiltration and cellular composition of infiltrates were investigated also. Primary liver reaction to the Con-A was the inflammatory changes in the vascular bed, followed by disturbances in the parenchyma.The sufficient increasing of leukocyte migration to the liver was revealed. Besides, the neutrophile infiltration was increased first with a maximum at 6 hours of the experiment (63,9 ±4,6%, p<0,001 to the control level) ,and then the lymphocyte infiltration was increased with creation of manycellular lymphocytemacrophage infiltrates (62% at 48 hours comparing to 6 hours of experiment) and sufficient quantity of plasma cells population (4,9%, p<0,05 comparing to 6 hours of experiment). The obtained data gives the base to suggest that the elevated infiltration of liver tissue by leukocytes, particularly by lymphocytes and monocytes, together with necrotic death increasing creats the conditions for effective intracellular interaction and immune response to autoantigenes. This can be the essential pathogenic mechanism of development of autoimmune liver deseases.

Association of increased rate of condemnation of broiler carcasses due to hepatic abnormalities with immunosuppressive diseases in the broiler chicken industry in Saskatchewan

The objective of this study was to identify the causative agents of hepatitis observed in broiler chickens at processing. Livers of chickens from 16 broiler farms in Saskatchewan with gross lesions of hepatitis were collected at processing. In addition to routine bacterial isolation and histopathological examination, serologic studies for infectious bursal disease virus (IBDV) and Chicken anaemia virus (CAV), calculation of the ratio of the weight of the bursa of Fabricius (BF) to body weight (BBW), and histopathological examination of the BF were done. Of the 264 livers with gross lesions, 83% had multifocal to coalescing necrotizing hepatitis, 16% had perihepatitis, and 1% had hemorrhages. No definitive causative microorganisms were isolated from the hepatic lesions; however, no significant bacterial isolations were made. Bursal atrophy, low BBW ratio, and high titer of antibody against IBDV each correlated with the rate of total condemnations (P = 0.0188, P = 0.0001, and P = 0.0073, respectively). Nucleotide sequencing of IBDV isolated from the BF identified the variant strains Delaware-E and 586. Condemnation because of hepatic lesions was correlated with titer of antibody against IBDV and BBW (P = 0.016 and P = 0.027). The results of this study demonstrate that hepatic lesions in Saskatchewan chickens are not currently caused by a primary bacterial pathogen but are associated with indicators of immunosuppression that is likely due to variant IBDV.

1,25-(OH)₂-vitamin D₃ prevents activation of hepatic stellate cells in vitro and ameliorates inflammatory liver damage but not fibrosis in the Abcb4(-/-) model

BACKGROUND/PURPOSE OF THE STUDY

Vitamin D3-deficiency is common in patients with chronic liver-disease and may promote disease progression. Vitamin D3-administration has thus been proposed as a therapeutic approach. Vitamin D3 has immunomodulatory effects and may modulate autoimmune liver-disease such as primary sclerosing cholangitis. Although various mechanisms of action have been proposed, experimental evidence is limited. Here we test the hypothesis that active 1,25-(OH)2-vitamin D3 inhibits activation of hepatic stellate cells (HSC) in vitro and modulates liver-injury in vivo.

METHODS

Proliferation and activation of primary murine HSC were assessed by BrdU- and PicoGreen(®)-assays, immunoblotting, immunofluorescence-microscopy, quantitative-PCR, and zymography following calcitriol-treatment. Wild-type and ATP-binding cassette transporter b4(-/-) (Abcb4(-/-))-mice received calcitriol for 4 weeks. Liver-damage, inflammation, and fibrosis were assessed by serum liver-tests, Sirius-red staining, quantitative-PCR, immunoblotting, immunohistochemistry and hydroxyproline quantification.

RESULTS

In vitro, calcitriol inhibited activation and proliferation of murine HSC as shown by reduced α-smooth muscle actin and platelet-derived growth factor-receptor-β-protein-levels, BrdU and PicoGreen®-assays. Furthermore, mRNA-levels and activity of matrix metalloproteinase 13 were profoundly increased. In vivo, calcitriol ameliorated inflammatory liver-injury reflected by reduced levels of alanine aminotransferase in Abcb4(-/-)-mice. In accordance, their livers had lower mRNA-levels of F4/80, tumor necrosis factor-receptor 1 and a lower count of portal CD11b positive cells. In contrast, no effect on overall fibrosis was observed.

CONCLUSION

Calcitriol inhibits activation and proliferation of HSCs in vitro. In Abcb4(-/-)-mice, administration of calcitriol ameliorates inflammatory liver-damage but has no effect on biliary fibrosis after 4 weeks of treatment.

Rift Valley fever virus infection in golden Syrian hamsters

Rift Valley fever virus (RVFV) is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.

Mesenteric and splenic contributions to portal venous CT perfusion in hepatic diffuse disease

AIM

To investigate the changes and contributions of superior mesenteric venous perfusion (SMVP) and splenic venous perfusion (SpVP) to portal venous CT perfusion in canine model of hepatic diffuse disease.

MATERIALS AND METHODS

By selective catheterization in superior mesenteric and splenic arteries respectively after CT perfusion scanning, SMVP and SpVP became available. Sixteen dogs were adopted and induced by carbon tetrachloride after data under normal conditions were collected. After 3, 6, 9 and 12 months from carbon tetrachloride intervention, liver biopsies by puncture or operation were performed after CT perfusion scanning. SMVP and SpVP under different pathologic conditions were compared and analyzed.

RESULTS

Three stages of hepatic diffuse lesions were defined according to pathologic changes, namely hepatitis, hepatic fibrosis, and cirrhosis. The number of dogs which survived from each stage was: 16 from normal, 12 from hepatitis, 10 from hepatic fibrosis and 4 from cirrhosis. During this progressive period, SpVP ml/(min·100 ml) declined slightly, but there were no significant differences between different stages (P > 0.05). SMVP ml/(min·100 ml) in stage of normal (64.1 ± 8.1) and hepatic fibrosis (44.4 ± 4.5), normal and cirrhosis (42.6 ± 5.4), hepatitis (61.3 ± 6.4) and hepatic fibrosis, hepatitis and cirrhosis was significantly different, but there was no significant difference of SMVP between normal and hepatitis (P = 0.326) or hepatic fibrosis and cirrhosis (P = 0.668).

CONCLUSIONS

With our evidence of interventional CT perfusion, it is mesenteric, not splenic, perfusion that might coincide with hepatic portal venous perfusion during the progressive period of hepatic diffuse disease.

[The ultrastructural organization of the liver of rats with experimental hepatitis after drinking mineral water containing humic acids]

We undertook the ultrastructural analysis of liver parenchyma taken from male rats with experimental hepatitis induced by the administration of paracetamol at a dose of 1000 mg per 1 kg body weight either following a course of drinking mineral water containing humic acids at a concentration of 20 mg/sq. decimeter) or 14 days after the termination of the drug action (the after-effect phase). It was shown that the consumption of mineral water during 21 days resulted in the modification of the ultrastructural organization of hepatocytes apparent as the increased amount of cisterns in the granulosa endoplasmic system, glycogen rosettes, and mitochondrial polymorphism. These changes give evidence of the restoration of the energy, glycogen and protein synthesizing functions disturbed by paracetamol administration. The after-effect phase was characterized by the further strengthening of reparative processes and the functional activity of hepatic cells.

Tyzzer's disease in foals: retrospective studies from 1969 to 2010

Reports of 148 cases of Tyzzer's disease in foals in central Kentucky were analyzed to identify features of the disease and factors associated with it. The records indicate that Tyzzer's disease is a rapidly progressive, highly fatal hepatitis caused by Clostridium piliforme. Common clinical findings are lethargy, fever, anorexia, and icterus. Seizures, coma, and death may rapidly ensue. Laboratory findings are leukopenia, metabolic acidosis, hypoglycemia, and increased activity of hepatic enzymes. Diagnosis is primarily based on clinical signs and postmortem findings but a polymerase chain reaction (PCR) is now available to detect C. piliforme DNA in organs and feces. Disease occurred most frequently in foals between 9 and 30 days of age that were born in April to May and was associated with heavy rainfall in the spring and high protein and nitrogenous diets fed to nursing mares. The findings are consistent with the ingestion of C. piliforme in the feces of adult horses and overgrowth in the intestine of foals with a high level of nutrients in their intestine.

Histopathological lesions and DNA adducts in the liver of European flounder (Platichthys flesus) collected in the Seine estuary versus two reference estuarine systems on the French Atlantic coast

An epidemiological survey was conducted in the Seine estuary and in two smaller and relatively preserved estuaries on the French Atlantic coast in order to estimate the occurrence of liver lesions in European flounder, Platichthys flesus, and also to seek putative risk factors for the recorded pathologies. Four hundred and seventy-eight fish of both sexes and of different size ranges were sampled in the three studied areas, 338 of which in the Seine estuary. All fish were examined for histopathological liver lesions, while DNA adducts and otoliths were analyzed on a subsample. Five categories of hepatic lesions were recorded with the following prevalence for the Seine estuary: 36.7 % inflammations, 8 % parasites (mainly encysted nematodes), 6.5 % foci of cellular alteration (FCA), 5.3 % foci of necrosis or regeneration (FNR), and 1.5 % tumors. Inflammation occurrence increased according to age, contrary to parasitic infestations and FCA which were more prevalent in young fish, notably those of <1 year old (group 0). Tumors were only observed in females of more than two winters. Females exhibited a higher prevalence of tumors (3.0 %) and FCA (6.5 %) than males (0 and 2.6 %, respectively). Parasitic and infectious lesions and FNR were equally distributed in males and females. The prevalence of FNR was also shown to vary according to sampling season, with significantly more occurrences of liver necrosis in the fish collected in summer than in spring. Spatial differences were observed with a higher occurrence of encysted parasites in flounders from the upper Seine estuary, while inflammations predominated in flounders living downstream. Temporal trends were also noted, with an increased prevalence of parasitic infestations, inflammations, and FCA in the 2002-2003 period in comparison to the 1996-1997 one. The three flounder populations from the Seine estuary (Normandy), Ster estuary (Brittany), and Bay of Veys (Normandy) showed different spectra of hepatic lesions. Flounders from the Bay of Veys had relatively few liver lesions as compared to flounders from the two other estuaries. Flounders from the Ster estuary exhibited the highest prevalence of parasites (37.2 %) and inflammations (51.1 %). Finally, FCA and liver tumors occurred at very similar levels in both flounder populations from the Seine and the Ster estuaries. Group 0 flounders inhabiting the upper Seine estuary were more prone to parasitic and pre-neoplastic hepatic lesions and had higher levels of liver DNA adducts than the older ones living downstream. It was postulated that group 0 European flounders may serve as valuable bioindicators for assessing the quality of estuarine waters and the health status of euryhaline fish populations.

Endosulfan induced early pathological changes in vital organs of rat: a biochemical approach

AIM

To evaluate the pathogenesis in heart and liver by the early induction of biochemical and antioxidant derangements in rats exposed to endosulfan.

MATERIALS AND METHODS

Wistar rats were gavaged with endosulfan (0.5, 1 and 1.5 mg/kg body weight in sunflower oil) for a period of 21 days (single dose at 24 h interval). Control and sunflower oil control groups were also maintained simultaneously. Rats were sacrificed on the 22(nd) day posttreatment. Blood samples, heart and liver were collected and different biochemical parameters such as total protein, cholesterol, triglycerides, amino acids and antioxidant and lipid peroxidation level were measured. Statistical analysis was carried out by one way ANOVA, followed by Bonferroni' post-hoc test.

RESULTS

Endosulfan induced a significant increase in the serum levels of total protein, amino acids, triglyceride, total cholesterol, free fatty acid and phospholipid levels in a dose-dependent manner. In the heart and liver, lipid peroxidation was increased significantly in a dose-dependent manner and the antioxidant levels such as superoxide dismutase (SOD), glutathione S-transferase, glutathione peroxidase, and catalase were significantly decreased in a dose-dependent pattern.

CONCLUSION

Exposure to endosulfan results in a significant derangement in the biochemical parameters with a decrease in antioxidant levels in the heart and liver. This is an early indication of pathogenesis in the vital organs of rats.

[Two cases of disseminated toxoplasmosis]

Two cases of disseminated fatal toxoplasmosis of a pet mouse and a red panda are described. The pet mouse had a private owner; the red panda lived in a zoological garden in Saxony. At necropsy, both animals suffered from a systemic toxoplasmosis. A severe necrotizing hepatitis was the main histological feature in both animals. Parasitic cysts could be abundantly found in the liver, moderately in the brain and in a low number in other organs. With the PAS-reaction, cysts showed a weak staining in the mouse and a strong staining in the red panda. Diagnosis was confirmed by PCR and immunohistochemistry.

[Hepatoprotective effect of thiophane in rats with experimental carbon tetrachloride-induced hepatitis]

A hepatoprotective effect of thiophan was studied on the model of carbon tetrachloride-induced hepatitis in rats. Therapeutic administration of thiophan repairs the antitoxic function of liver, normalizes cytolysis marker activity, and improves the synthetic function of liver and the carbohydrate and lipid metabolism. The hepatoprotective activity of thiophan is similar to effect of silimarin.

Chromobacterium pathogenicity island 1 type III secretion system is a major virulence determinant for Chromobacterium violaceum-induced cell death in hepatocytes

Chromobacterium violaceum is a Gram-negative bacterium that causes fatal septicaemia in humans and animals. C. violaceum ATCC 12472 possesses genes associated with two distinct type III secretion systems (T3SSs). One of these systems is encoded by Chromobacterium pathogenicity islands 1 and 1a (Cpi-1/-1a), another is encoded by Chromobacterium pathogenicity island 2 (Cpi-2). Here we show that C. violaceum causes fulminant hepatitis in a mouse infection model, and Cpi-1/-1a-encoded T3SS is required for its virulence. In addition, using C. violaceum strains with defined mutations in the genes that encode the Cpi-1/-1a or Cpi-2 locus in combination with cultured mammalian cell lines, we found that C. violaceum is able to induce cytotoxicity in a Cpi-1/-1a-dependent manner. Characterization of Chromobacterium-induced cytotoxicity revealed that cell lysis by C. violaceum infection involves the formation of pore structures on the host cell membrane, as demonstrated by protection by cytotoxicity in the presence of osmoprotectants. Finally, we demonstrated that CipB, a Cpi-1/-1a effector, is implicated in translocator-mediated pore formation and the ability of CipB to form a pore is essential for Chromobacterium-induced cytotoxicity. These results strongly suggest that Cpi-1/-1a-encoded T3SS is a virulence determinant that causes fatal infection by the induction of cell death in hepatocytes.

Characterisation of the hepatic progenitor cell compartment in normal liver and in hepatitis: an immunohistochemical comparison between dog and man

The liver progenitor cell compartment in the normal canine liver and in spontaneous canine acute (AH) and chronic hepatitis (CH) was morphologically characterised and compared to its human equivalents. Immunohistochemistry was performed for cytokeratin-7 (CK7), human hepatocyte marker (Hep Par 1), multidrug resistance-associated protein-2 (MRP2), and breast cancer resistance protein (BCRP) on paraffin and frozen sections from canine and human tissues. Normal liver showed similar morphology and immunohistochemical reaction of the progenitor cell compartment/canal of Hering in man and dog. In addition, a ductular reaction, comparable in terms of severity, location and immunohistochemical characteristics, was observed in canine and human AH and CH. CK7 was a good marker for canine progenitor cells, including intermediate cells, which were positively identified in cases of AH and CH. In both species, BCRP was expressed in both hepatocytes and bile ducts of the normal liver, and in ductular reaction in AH and CH. MRP2 detected bile canalicular membranes in man and dog. These findings underline the similarities between canine and human liver reaction patterns and may offer mutual advantage for comparative research in human and canine spontaneous liver diseases.

Intestinal, adipose, and liver inflammation in diet-induced obese mice

Chronic inflammation and increased visceral adipose tissue (VAT) are key elements of the metabolic syndrome. Both are considered to play a pathogenic role in the development of liver steatosis and insulin resistance. The aim of the present study was to investigate the hypothesis that an inflamed intestine, induced both by diet and chemical irritation, could induce persistent inflammation in VAT. Female C57BL/6JOlaHsd mice were used. In study I, groups of mice (n = 6 per group) were given an obesity-inducing cafeteria diet (diet-induced obesity) or regular chow only (control) for 14 weeks. In study II, colitis in mice (n = 8) was induced by 3% dextran sulfate sodium in tap water for 5 days followed by 21 days of tap water alone. Healthy control mice (n = 8) had tap water only. At the end of the studies, all mice were killed; and blood and tissues were sampled and processed for analysis. Body weight of diet-induced obese mice was greatly increased, with evidence of systemic inflammation, insulin resistance, and liver steatosis. Tissue inflammation indexed by proinflammatory cytokine expression was recorded in liver, mesenteric fat, and proximal colon/distal ileum, but not in subcutaneous or perigonadal fat. In dextran sulfate sodium-induced colitis mice, mesenteric fat was even more inflamed than the colon, whereas a much milder inflammation was seen in liver and subcutaneous fat. The studies showed both diet- and colitis-initiated inflammation in mesenteric fat. Fat depots contiguous with intestine and their capacity for exaggerated inflammatory responses to conditions of impaired gut barrier function may account for the particularly pathogenic role of VAT in obesity-induced metabolic disorders.

[Hepatoprotective effect of Gossipium hirsutum extract on acute experimental hepatitis on rat liver injury]

OBJECTIVE

To investigate the protective effect on the mice acute experimental hepatic injury by Flos Gossypium herbaceum extracts (FGF-I, FGF-II).

METHOD

Experimental hepatic injury model was established by a single intraperitoneal injection of 350 mg x kg(-1) D-CalN in Wistar rats. Serum samples for alanine aminotransferase (ALT), aspartate transferase (AST) level and liver homogenate samples for super oxide dismutase (SOD), malondialdehyde (MDA), Glutathione peroxidese (GSH-PX) activities were assayed.

RESULT

For acute experimental hepatic injury, FGF-I and FGF-II significantly decrease the serum transaminase activities (P < 0.01). FGF-I increased the SOD activities (P < 0.01), and decreased MDA content only for 50 mg x kg(-1) FGF-I (P < 0.05), no effect on GSH-PX activity was found for them. FGF-II increased the SOD and GSH-PX activity (P < 0.05) with decreased MDA content (P < 0.05).

CONCLUSION

FGF-I and FGF-II showed significant protective action in mice experimental hepatic injury.

Enhanced expression of transforming growth factor-beta 1 in inflammatory cells, alpha-smooth muscle actin in stellate cells, and collagen accumulation in experimental granulomatous hepatitis caused by Toxocara canis in mice

Although toxocaral granulomatous hepatitis (TGH) characterized with a dominant-Th2 type immune response is a self-limiting disease, little is known concerning the role of fibrosis-related cytokine transforming growth factor-beta 1 (TGF-beta 1) in pathogenesis of TGH. A detailed histological and quantitatively immunohistochemical analysis of TGF-beta 1, alpha-smooth muscle actins (alpha-SMA), and collagen was performed on the liver tissues from mice infected with Toxocara canis as assessed between day 1 and 42 weeks post-infection (DPI or WPI). TGF-beta1 was detected mainly in infiltrating leukocytes in lesions with strong expressions from 4 to 16 WPI. Larvae per se also exhibited strong TGF-beta 1-like molecule expressions in the trial. Alpha-SMA was detected predominantly in hepatic stellate cells (HSC) which surrounded the lesions with moderate expressions largely throughout the period of the entire experiment. Collagen was observed to accumulate in inflammatory lesions and biliary basement with moderate to strong expressions from 1 WPI onwards in the trial. Since many evidences have indicated that leukocytes have the potential to influence HSC by producing TGF-beta 1 which can affect HSC to increase collagen synthesis in various liver diseases, we may propose that persistently elevated TGF-beta 1 expression in infiltrating leukocytes and active HSC with marked alpha-SMA expressions may contribute to healing of injured sites through up-stimulation of collagen deposition; in contrast, abnormally persistent collagen accumulation may cause irreversible fibrotic injury in the TGH.

Methionine deficiency and hepatic injury in a dietary steatohepatitis model

Methionine (Meth) is an essential amino acid involved in DNA methylation and glutathione biosynthesis. We examined the effect of Meth on the development of steatohepatitis. Rats were fed (five weeks) amino acid-based Meth-choline-sufficient (A-MCS) or total deficient (MCD) diets and gavaged daily (two weeks) with vehicle (B-vehicle/MCD), or Meth replacement (C-Meth/MCD). To assess the effect of short-term deficiency, after three weeks one MCS group was fed a deficient diet (D-MCS/MCD). Animals fed the deficient diet for two weeks lost (29%) weight and after five weeks weighed one third as much as those on the sufficient diet, and also developed anemia (P < 0.01). Hepatic transaminases progressively increased from two to five weeks (P < 0.01), leading to severe hepatic pathology. Meth administration normalized hematocrit, improved weight (P < 0.05), and suppressed abnormal enzymes activities (P < 0.01). Meth administration improved blood and hepatic glutathione (GSH), S-adenosylmethionine (SAMe), and hepatic lesions (P < 0.01). The deficient diet significantly upregulated proinflammatory and fibrotic genes, which was ameliorated by Meth administration. These data support a pivotal role for methionine in the pathogenesis of the dietary model of Meth-choline-deficient (MCD) steatohepatitis (NASH).

Hepatic encephalopathy in a pregnant mare: identification of histopathological changes in the brain of a mare and fetus

An 11-year-old Thoroughbred broodmare was evaluated for suspected hepatic dysfunction. Clinical signs of hepatic encephalopathy were evident at admission. Hepatic ultrasonographic evaluation revealed an increase in hepatic size, rounded borders and normal echogenicity. There was no evidence of cholelithiasis or bile duct distention. Increased activity of hepatic enzymes, increased bile acid and bilirubin concentration and an increased ammonia concentration were supportive of a diagnosis of hepatic disease and hepatic encephalopathy. Histopathological evaluation of a liver biopsy specimen was consistent with chronic active hepatitis. The mare was treated with intravenous fluids and antimicrobials, pentoxyfilline, branched-chain amino acids and dietary manipulation. Clinical improvement was observed initially; however, 3 weeks later, deterioration in the mare's condition necessitated euthanasia. Pathological lesions at necropsy were restricted to the liver and brain. The liver was diffusely firm with a prominent reticular pattern on the cut surface. A large choledocholith was present in the main bile duct of the left liver lobe. Histopathological examination of the liver revealed severe fibrosis, with hyperplastic bile ducts and mononuclear and neutrophilic inflammation. Pathological changes consistent with hepatic encephalopathy, (Alzheimer type II cells), were evident in the cerebrum of both the mare and the fetus.

Toll-like receptor-4 signaling and Kupffer cells play pivotal roles in the pathogenesis of non-alcoholic steatohepatitis

BACKGROUND/AIMS

Studies in animal models and humans suggest a link between endotoxemia and non-alcoholic steatohepatitis. Since Kupffer cells are responsible for clearing endotoxin and are activated via endotoxin interaction with Toll-like receptor 4 (TLR-4), we examined the relationship between hepatic TLR-4 expression and Kupffer cell content during the genesis of steatohepatitis.

METHODS

Male C57BL/6, C3H/HouJ and TLR-4 mutant C3H/HeJ mice were fed control or methionine/choline-deficient diet (MCDD). In one group of C57BL/6 mice, Kupffer cells were depleted by weekly intraperitoneal injections of clodronate liposomes. After 3 weeks, serum ALT activity and portal endotoxin levels were measured. Real-time PCR was used to examine mRNA expression of TLR-4, TLR-2, CD14, MD-2, TGFbeta, TNFalpha, CD36, PPAR-alpha, liver fatty acid binding protein (L-FABP) and collagen alpha1.

RESULTS

We observed histological evidence typical of steatohepatitis, portal endotoxemia and enhanced TLR-4 expression in wild type mice fed MCDD. In contrast, injury and lipid accumulation markers were significantly lower in TLR-4 mutant mice. Destruction of Kupffer cells with clodronate liposomes blunted histological evidence of steatohepatitis and prevented increases in TLR-4 expression.

CONCLUSIONS

These findings demonstrate the importance of TLR-4 signaling and underscore a direct link between TLR-4 and Kupffer cells in the pathogenesis of steatohepatitis.

Hypoadiponectinemia accelerates hepatic tumor formation in a nonalcoholic steatohepatitis mouse model

BACKGROUND/AIMS

Adipose tissue produces a number of adipocytokines, including adiponectin, leptin, and tumor necrosis factor-alpha. Obesity, which is associated with low plasma adiponectin levels, is an independent risk factor for various liver diseases including nonalcoholic steatohepatitis (NASH). The aim of this study was to examine the effects of adiponectin on the progression of NASH to cirrhosis and tumor formation using adiponectin-knockout (KO) mice.

METHODS

Using a choline-deficient L-amino acid-defined (CDAA) diet-induced mouse NASH model, liver histology and oxidative stress markers were investigated in KO and wild-type (WT) mice.

RESULTS

Hepatic steatosis was enhanced to a greater extent in KO mice, compared to WT mice after a 1-week CDAA diet. After 24 weeks, 6 out of 14 KO mice developed liver cirrhosis and hepatic tumors, whereas the 15 WT mice showed only simple steatosis. In KO mice, hepatic cytochrome P450 2E1 levels were upregulated, and markers of oxidative stress (thiobarbituric acid reactive substances, 8-hydroxydeoxyguanosine-positive cells) were significantly increased compared with WT mice.

CONCLUSIONS

Our results indicate that lack of adiponectin enhances the progression of hepatic steatosis, fibrosis, and hepatic tumor formation in an animal model of NASH. Hypoadiponectinemia in obesity could be a risk factor for NASH-related hepatic tumor formation.

micro-Opioid receptor activation prevents acute hepatic inflammation and cell death

BACKGROUND AND AIMS

The detrimental impact of opioid agonist on the clinical management of inflammatory diseases remains elusive. Given the anti-inflammatory properties of the mu-opioid receptor (MOR) agonists at the intestinal barrier, we hypothesised that MOR activation might also dampen acute hepatic inflammation and cell death-major determinants in the pathogenesis of liver diseases.

PATIENTS AND METHODS

The expression of MOR in liver biopsy specimens and peripheral blood mononuclear cells of untreated patients with chronic hepatitis C virus infection and controls, primary hepatocytes and cell lines was determined by quantitative PCR, immunoblotting and/or immunohistochemistry. The effects of peripheral MOR agonist (d-Ala2,NMe-Phe4,Gly5-ol (DAMGO)) and/or antagonist (naloxone methiodide) were explored in two models of acute hepatitis in mice. MOR-deficient mice were used to evaluate the essential regulatory role of MOR during carbon tetrachloride (CCl(4))-induced hepatitis. The role of DAMGO in cell death was investigated using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) analysis and quantification of lactate dehydrogenase release.

RESULTS

The key role of MOR in the prevention of acute hepatic inflammation and cell death in vivo and in vitro is reported. Whereas MOR gene expression increased transiently in the model of acute liver injury and TNFalpha-treated HepG2 cells, an impaired expression of MOR mRNA in human chronic hepatitis C samples was found. Furthermore, preventive administration of the selective MOR agonist DAMGO enhanced hepatoprotective-signalling pathways in vivo that were blocked by using naloxone methiodide. Consistently, genetic and pharmacological inhibition of MOR enhanced the severity associated with experimental hepatotoxin-induced hepatitis. Finally, treatment with DAMGO was shown to prevent cell death in vitro in HepG2 cells in a MOR-dependent manner and to prevent concanavalin A- and CCl(4)-induced cell death in vivo, providing a possible explanation for the anti-inflammatory role of MOR activation in the liver.

CONCLUSIONS

The results indicate that MOR agonists may prevent acute hepatitis and hold promising therapeutic use to maintain remission in both chronic inflammatory bowel and liver diseases.

Expression of a cyclo-oxygenase-2 transgene in murine liver causes hepatitis

BACKGROUND

It has been proved that cyclo-oxygenase-2 (COX-2) is rapidly induced by inflammatory mediators. However, it is not known whether overexpression of COX-2 in the liver is sufficient to promote activation or secretion of inflammatory factors leading to hepatitis.

AIM

To investigate the role forced expression of COX-2 in liver by using inducible COX-2 transgenic (TG) mice.

METHODS

TG mice that overexpress the human COX-2 gene in the liver using the liver-specific transthyretin promoter and non-TG littermates were derived and fed the normal diet for up to 12 months. Hepatic prostaglandin E(2) (PGE(2)) content was determined using enzyme immunoassay, nuclear factor kappaB (NF-kappaB) activation by electrophoretic mobility shift assays, apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labelling and proliferation by Ki-67 immunohistochemistry.

RESULTS

COX-2 TG mice exhibited strongly increased COX-2 and PGE(2), elevated serum alanine aminotransferase level and histological hepatitis. Hepatic COX-2 expression in the TG mice resulted in activation of NF-kappaB and inflammatory cytokine cascade, with a marked expression of the proinflammatory cytokines tumour necrosis factor (TNF)-alpha (9.4-fold), interleukin (IL)-6 (4.4-fold), IL-1beta (3.6-fold), and of the anti-inflammatory cytokine IL-10 (4.4-fold) and chemokine macrophage inflammatory protein-2 (3.2-fold). The inflammatory response of the COX-2 TG mice was associated with infiltration macrophages and lymphocytes, increased cell proliferation and high rates of cell apoptosis. Administration of the COX-2 inhibitor celecoxib in TG mice restored liver histology to normal.

CONCLUSION

Enhanced COX-2 expression in hepatocytes is sufficient to induce hepatitis by activating NF-kappaB, stimulating the secretion of proinflammatory cytokines, recruiting macrophage and altering cell kinetics. Inhibition of COX-2 represents a mechanism-based chemopreventive approach to hepatitis.

Thymic stromal lymphopoietin transgenic mice develop cryoglobulinemia and hepatitis with similarities to human hepatitis C liver disease

Essential mixed cryoglobulinemia in humans is strongly associated with chronic hepatitis C virus infection. It remains controversial whether liver injury in hepatitis C is primarily attributable to direct viral cytopathic effect or to an immune-mediated response. We characterized the role of cryoglobulinemia in the development of liver disease in thymic stromal lymphopoietin (TSLP) transgenic mice that produce mixed cryoglobulinemia and develop hepatitis. The role of immune complexes in this animal model was evaluated using techniques of light, immunofluorescence, and electron microscopy. To assess the role of Fc receptor engagement in mediation of the disease, TSLP transgenic mice were crossbred with mice deficient for immunoglobulin-binding receptor gamma IIb (FcgammaRIIb). Livers from the TSLP transgenic animals showed mild to moderate liver injury, minimal to mild fibrosis, and deposition of immunoglobulin around the portal tracts. TSLP transgenic mice deficient in inhibitory FcgammaRIIb had more severe hepatitis and accelerated mortality. TSLP-associated hepatitis bears strong similarity to hepatitis C virus-related hepatitis as it occurs in humans, making this a valuable model system of chronic hepatitis and fibrosis to study therapies aimed at manipulating immune responses. Periportal immune complex deposition may play an important role in the pathogenesis of hepatitis occurring in the setting of systemic cryoglobulinemia.

Rosiglitazone attenuates suppression of RXRalpha-dependent gene expression in inflamed liver

BACKGROUND/AIMS

A recently determined target of lipopolysaccharide (LPS) and cytokine signaling in liver is the central Type II nuclear receptor (NR) heterodimer partner, retinoid X receptor alpha (RXRalpha). We sought to determine if Rosiglitazone (Rosi), a peroxisome proliferator activated receptor gamma (PPARgamma) agonist with anti-inflammatory properties, can attenuate LPS and cytokine-induced molecular suppression of RXRalpha-regulated genes.

METHODS

In vivo, mice were gavage-fed Rosi for 3 days, prior to intraperitoneal injection of LPS, followed by harvest of liver and serum. In vitro, HepG2 cells were treated with IL-1beta, +/- short-term Rosi pretreatment. RNA was analyzed by quantitative RT-PCR, while nuclear and cytoplasmic proteins were analyzed by immunoblotting and gel shifts.

RESULTS

Rosi attenuated LPS-mediated suppression of RNA levels of several Type II NR-regulated genes, including bile acid transporters and the major drug metabolizing enzyme, Cyp3a11, without affecting cytokine expression, suggesting a novel, direct anti-inflammatory effect in hepatocytes. Rosi suppressed the inflammation-induced nuclear export of RXRalpha, in both LPS-injected mice and IL-1beta-treated HepG2 cells, leading to maintenance of nuclear RXRalpha levels and heterodimer binding activity.

CONCLUSIONS

Rosi directly attenuates the suppressive effects of inflammation-induced cell signaling on nuclear RXRalpha levels in liver.

Enterohepatic Helicobacter species isolated from the ileum, liver and colon of a baboon with pancreatic islet amyloidosis

Microaerobic bacteria were isolated from a baboon with pancreatic islet amyloidosis and hepatitis. Phenotypic and molecular analyses identified two distinct helicobacters. Analyses of 16S rRNA demonstrated "Helicobacter macacae" in the ileum and liver, and Helicobacter cinaedi in the colon. To the best of the authors' knowledge, this is the first report describing the isolation of enterohepatic Helicobacter species from a baboon.

Transforming growth factor beta-1 signalling in canine hepatic diseases: new models for human fibrotic liver pathologies

BACKGROUND/AIMS

The purpose of this study was to validate spontaneous chronic hepatitis and cirrhosis in dogs as a potential large animal model for fibrotic liver disease in humans by evaluating their molecular pathophysiology.

METHODS

Transforming growth factor-beta1 (TGF-beta1) signalling was analysed in liver samples of dogs with acute hepatitis (AH), chronic hepatitis (CH), cirrhosis (CIRR), and a specific form of cirrhosis, lobular dissecting hepatitis (LDH), in comparison with human cirrhotic samples from alcohol abuse (ALC) and hepatitis C (HC).

RESULTS

Canine samples were investigated with quantitative real-time PCR (Q-PCR) and Western blotting on TGF-beta1 signalling including Smad2/3 phosphorylation. Immunohistochemistry on collagens I and III was performed. Q-PCR showed an increase in TGF-beta1 levels and downstream effector gene products in CH, LDH, and CIRR. The same fibrotic diseases also showed an increase in phosphorylated Smad2/3 and a higher deposition of collagens I and III. In contrast, in AH neither active TGF-beta1 signalling nor collagen deposition was observed. Western blot analysis on human ALC and HC indicated a high similarity with canine samples in TGF-beta1 expression and Smad2/3 phosphorylation.

CONCLUSIONS

Our results demonstrate that fibrosis in spontaneous dog liver diseases is highly comparable to their human counterparts and might serve as models for anti-fibrotic strategies.

Influence of disease stage on polyethylenimine-mediated plasmid DNA delivery in murine hepatitis

In order to determine the influence of hepatic disease-stage on polyethylenimine-mediated gene delivery, we investigated branched and linear polyethylenimine (B-PEI, L-PEI)-mediated plasmid DNA delivery with time in murine hepatitis induced by a subcutaneous injection of tetrachloro carbon (CCl(4)). Plasmid DNA (pDNA) encoding firefly luciferase was used as the model reporter gene. We determined luciferase activity in various organs of CCl(4)-treated mice and control mice after an intravenous administration of B-PEI and L-PEI/pDNA complexes. Both B-PEI and L-PEI/pDNA complexes showed significantly lower gene expression in the liver, spleen, and lung at the stage of severe hepatitis (18 h after CCl(4) injection), whereas the complexes induced gene expression in the liver at the liver regeneration stage (48 h after CCl(4) injection). Significant differences in gene expressions between CCl(4)-treated mice and control mice vanished in most organs at the hepatitis subsidence stage (168 h after CCl(4) injection), indicating that the influence of hepatitis induced by CCl(4) was reversible with PEI-mediated gene delivery. Our findings demonstrated that murine hepatitis induced by CCl(4) could influence polyethylenimine-mediated plasmid DNA delivery according to the disease stage. These results indicate the necessity of considering the timing and dose of gene therapy according to the disease stage.

Melatonin-selenium nanoparticles inhibit oxidative stress and protect against hepatic injury induced by Bacillus Calmette-Guérin/lipopolysaccharide in mice

Melatonin-selenium nanoparticles (MT-Se), a novel complex, were synthesized by preparing selenium nanoparticles in melatonin medium. The present investigation was designed to determine the protective effects of MT-Se against Bacillus Calmette-Guérin (BCG)/lipopolysaccharide (LPS)-induced hepatic injury in mice. In BCG/LPS-induced hepatic injury model, MT-Se administered (i.g.) at doses of 5, 10, or 20 mg/kg to BCG/LPS-treated mice for 10 days, significantly reduced the increase in plasma aminotransferase, reduced the severe extent of hepatic cell damage and the immigration of inflammatory cells. The MT-Se particles also attenuated the increase in the content of thiobarbituric acid-reactive substances and enhanced the decrease in reduced activities of superoxide dismutase and glutathione peroxidase (GPx). However, treatment with MT-Se suppressed the increase in nitric oxide levels both in plasma and liver tissue. Furthermore, supplementation with MT-Se at the dose of 10 mg/kg (composed of 9.9 mg/kg melatonin and 0.1 mg/kg selenium) had great capability to protect against hepatocellular damage than a similar dose of melatonin (10 mg/kg) or selenium (0.1 mg/kg) alone. This effect may relate to its higher antioxidant efficacy in decreasing lipid peroxidation and increasing GPx activity. These results suggest that the mode of MT-Se hepatic protective action is, at least in part, related to its antioxidant properties.

Effect of diphenyl dimethyl bicarboxylate on concanavalin A-induced liver injury in mice

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

Preventive effects of soyasapogenol B derivatives on liver injury in a concanavalin A-induced hepatitis model

To shed light on the structure-activity relationship, various soyasapogenol B derivatives were synthesized and evaluated for preventive effects on liver injury in the concanavalin A (Con A)-induced hepatitis model in mice. Con A injection into mice induces some pathophysiology of human liver disease such as autoimmune or viral hepatitis. Two hydroxyl groups on the A ring of soyasapogenol B are required for amelioration of liver damage. Modification of the C-22 hydroxyl moiety with an acyloxy or alkyloxy group, or removal of the hydroxyl group, resulted in a greatly enhanced percentage of alleviation. Among the series of soyasapogenol B derivatives examined, six compounds exhibited preventive effects on liver damage.

Efficacy of zinc supplementation in preventing acute hepatitis in Long-Evans Cinnamon rats

OBJECTIVES

Long-Evans Cinnamon (LEC) rats are characterized by an abnormal hepatic deposition of copper (Cu) due to a lack of the Cu-transporter P-type adenosine triphosphatase: accordingly, the strain is a good animal model of Wilson's disease. The effect of oral zinc (Zn) acetate treatment on the development of acute hepatitis and the biochemical parameters of Cu-induced liver damage was studied in 5-week-old LEC rats (n=52).

METHODS

Rats receiving 50 or 80 mg/ml/day Zn acetate by gavage and control rats receiving a daily dose of glucose solution 0.02 g/ml by gastric intubation were killed at 1, 2 or 8 weeks after the start of treatment.

RESULTS

Treatment with Zn acetate resulted in the prevention of acute hepatitis: 10 of the 13 untreated rats developed signs and symptoms compatible with acute hepatitis between the 6th and 7th week of treatment. Tissue metallothionein (MT) significantly increased in the treated rats and positively correlated with Zn concentrations within the liver. Control rats had a significantly higher iron concentration in the liver and kidneys compared with supplemented rats, after both short- and long-term experiments. 8-hydroxy-2'-deoxyguanosine amounts were significantly lower in untreated rats.

CONCLUSIONS

Zn acetate prevents acute hepatitis, by increasing tissue MT concentrations, reducing Cu absorption and interfering with Fe metabolism.

Hepatoprotective activity of Leucas hirta against CCl4 induced hepatic damage in rats

Methanol and aqueous leaf extracts of L. hirta demonstrated hepatoprotective activity against carbon tetrachloride induced liver damage in rats. The parameters studied were serum total bilirubin, total protein, alanine transaminase, aspartate transaminase and alkaline phosphatase activities. The hepatoprotective activity was also supported by histopathological studies of liver tissue. Results of the biochemical studies of blood samples of CCl4 treated animals showed significant increase in the levels of serum markers and decrease in total protein level reflecting the liver injury caused by CCl4. Whereas blood samples from the animals treated with methanol and aqueous leaf extracts showed significant decrease in the levels of serum markers and increase in total protein indicating the protection of hepatic cells. The results revealed that methanol leaf extract followed by aqueous extract of L. hirta could afford significant protection against CCl4 induced hepatocellular injury.