Metformin Modulates T Cell Function and Alleviates Liver Injury Through Bioenergetic Regulation in Viral Hepatitis.

Metformin is not only the first-line medication for the treatment of type 2 diabetes, but it is also effective as an anti-inflammatory, anti-oxidative and anti-tumor agent. However, the effect of metformin during viral hepatitis remains elusive. Using an adenovirus (Ad)-induced viral hepatitis mouse model, we found that metformin treatment significantly attenuated liver injury, with reduced serum aspartate transaminase (AST) and alanine transaminase (ALT) levels and liver histological changes, presumably via decreased effector T cell responses. We then demonstrated that metformin reduced mTORC1 activity in T cells from infected mice, as evidenced by decreased phosphorylation of ribosome protein S6 (p-S6). The inhibitory effects on the mTORC1 signaling by metformin was dependent on the tuberous sclerosis complex 1 (TSC1). Mechanistically, metformin treatment modulated the phosphorylation of dynamin-related protein 1 (Drp-1) and mitochondrial fission 1 protein (FIS1), resulting in increased mass in effector T cells. Moreover, metformin treatment promoted mitochondrial superoxide production, which can inhibit excessive T cell activation in viral hepatitis. Together, our results revealed a protective role and therapeutic potential of metformin against liver injury in acute viral hepatitis via modulating effector T cell activation via regulating the mTORC1 pathway and mitochondrial functions.

Glycyrrhetinic acid alleviates hepatic inflammation injury in viral hepatitis disease via a HMGB1-TLR4 signaling pathway.

Various human disorders are cured by the use of licorice, a key ingredient of herbal remedies. Glycyrrhizic acid (GL), a triterpenoid glycoside, is the aqueous extract from licorice root. Glycyrrhetinic acid (GA) has been reported to be a major bioactive hydrolysis product of GL and has been regarded as an anti-inflammatory agent for the treatment of a variety of inflammatory diseases, including hepatitis. However, the mechanism by which GA inhibits viral hepatic inflammatory injury is not completely understood. In this study, we found that, by consecutively treating mice with a traditional herbal recipe, licorice plays an important role in the detoxification of mice. We also employed a murine hepatitis virus (MHV) infection model to illustrate that GA treatment inhibited activation of hepatic inflammatory responses by blocking high-mobility group box 1 (HMGB1) cytokine activity. Furthermore, decreased HMGB1 levels and downstream signaling triggered by injection of a neutralizing HMGB1 antibody or TLR4 gene deficiency, also significantly protected against MHV-induced severe hepatic injury. Thus, our findings characterize GA as a hepatoprotective therapy agent in hepatic infectious disease not only by suppressing HMGB1 release and blocking HMGB1 cytokine activity, but also via an underlying viral-induced HMGB1-TLR4 immunological regulation axis that occurs during the cytokine storm. The present study provides a new therapy strategy for the treatment of acute viral hepatitis in the clinical setting.

Effects of traditional Chinese medicine formula Le-Cao-Shi on hepatitis B: In vivo and in vitro studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Formula Le-Cao-Shi (LCS) is a traditional Chinese medicine (TCM), which has long been used as a folk remedy against hepatitis B in China. The present study was conducted to evaluate the anti-hepatitis B effects of aqueous extract of LCS in vivo and in vitro. MATERIALS AND METHOD: we investigated the anti-HBV effects of LCS in vivo and in vitro with duck hepatitis B model and HepG2.2.15 cell line model, respectively. The serologic and cellular biomarkers and the histopathological changes were examined. RESULTS: By a duck hepatitis B model, the extract of LCS was found to restrain the expressions of duck hepatitis B surface antigen (DHBsAg), hepatitis B e antigen (DHBeAg), and HBV-DNA (DHBV-DNA). Moreover, LCS could decrease the levels of aspartate and alanine aminotransferases (AST and ALT) and ameliorate duck liver histological lesions. Correspondingly, in a HepG2.2.15 cellular model, LCS could also significantly inhibit the secretions of HBsAg and HBeAg. CONCLUSION: LCS exerted potent anti-hepatitis effects against the infection of HBV. The above results demonstrated the first-hand experimental evidences for the anti-hepatitis B efficiency of LCS. Our study provides a basis for further exploration and development of this promising compound prescription to treat hepatitis B disease.

Molecular cloning and expression analysis of ferritin, heavy polypeptide 1 gene from duck (Anas platyrhynchos).

H-ferritin is a core subunit of the iron storage protein ferritin, and is related to the pathogenesis of malignant diseases. A differential expressed sequence tag of the ferritin, heavy polypeptide 1 gene (FTH1) was obtained from our previously constructed suppression subtractive cDNA library from 3-day-old ducklings challenged with duck hepatitis virus type I (DHV-1). The expression and function of FTH1 in immune defense against infection remains largely unknown in ducks. In this study, the full-length duFTH1 cDNA was obtained using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends. It consisted of 153 basepairs (bp) 5'untranslated region (UTR), 183 bp 3'UTR, and 546 bp open reading frame that encodes a single protein of 181 amino acid residues. duFTH1 shares high similarity with FTH1 genes from other vertebrates. The amino acid sequence possesses the conserved domain of typical ferritin H subunits, including seven metal ligands in the ferroxidase center, one iron binding region signature, and a potential bio-mineralization residue (Thy(29)). Moreover, in agreement with a previously reported ferritin H subunit, we identified an iron response element in the 5'UTR. RT-PCR analyses revealed duFTH1 mRNA is widely expressed in various tissues. Real-time quantitative polymerase chain reaction analyses suggested that duFTH1 mRNA is significantly up-regulated in the liver after DHV-1 injection or polyriboinosinic polyribocytidylic acid (polyI:C) treatment, reaching a peak 4 h post-infection, and dropping progressively and returning to normal after 24 h. Our findings suggest that duFTH1 functions as an iron chelating protein subunit in duck and contributes to the innate immune responses against viral infections.

Antiviral and immune stimulant activities of glycyrrhizin against duck hepatitis virus.

This study was conducted to investigate the effect of glycyrrhizin as an immune stimulant against duck hepatitis virus (DHV). In vitro study was carried out to determine cytotoxic and antiviral effects of glycyrrhizin in VERO cells. In vivo study was performed on 40 one-day-old White Pekin ducklings. -and the birds weres divided into 4 groups: control, glycyrrhizin treated, vaccinated with live attenuated DHV vaccine and glycyrrhizin treated and vaccinated; to investigate the changes in immunity and challenge test. Blood samples were collected from each duckling for evaluation of cellular and humeral immunity. The in vitro results revealed that glycyrrhizin had antiviral and no toxic effects till 106 dilutions. Higher antibody titer was observed from the 5th week till the end of experiment in glycyrrhizin and vaccinated group. Treatment with glycyrrhizin alone or with DHV vaccine demonstrated a pronounced lymphocytic proliferation response after 4 days post-inoculation till the end of experiment, while vaccinated group revealed a pronounced proliferation response after 24 days post-inoculation. Treatment with glycyrrhizin alone or combination with DHV vaccine revealed good immune stimulant and antiviral effect against DHV.

Immunization with the gene expressing woodchuck hepatitis virus nucleocapsid protein fused to cytotoxic-T-lymphocyte-associated antigen 4 leads to enhanced specific immune responses in mice and woodchucks.

A number of options are available to modify and improve DNA vaccines. An interesting approach to improve DNA vaccines is to fuse bioactive domains, like cytotoxic-T-lymphocyte-associated protein 4 (CTLA-4), to an antigen. Such fusion antigens are expressed in vivo and directed to immune cells by the specific bioactive domain and therefore possess great potential to induce and modulate antigen-specific immune responses. In the present study, we tested this new approach for immunomodulation against hepadnavirus infection in the woodchuck model. Plasmids expressing the nucleocapsid protein (WHcAg) and e antigen (WHeAg) of woodchuck hepatitis virus (WHV) alone or in fusion to the extracellular domain of woodchuck CTLA-4 and CD28 were constructed. Immunizations of mice with plasmids expressing WHcAg or WHeAg led to a specific immunoglobulin G2a (IgG2a)-dominant antibody response. In contrast, fusions of WHcAg to CTLA-4 and CD28 induced a specific antibody response with comparable levels of IgG1 and IgG2a. Furthermore, the specific IgG1 response to WHcAg/WHeAg developed immediately after a single immunization with the CTLA-4-WHcAg fusion. Woodchucks were immunized with plasmids expressing WHeAg or the CTLA-4-WHcAg fusion and subsequently challenged with WHV. CTLA-4-WHcAg showed an improved efficacy in induction of protective immune responses to WHV. In particular, the anti-WHsAg antibody response developed earlier after challenge in woodchucks that received immunizations with CTLA-4-WHcAg, consistent with the hypothesis that anti-WHs response is dependent on a Th cell response to WHcAg. In conclusion, the use of fusion genes represents a generally applicable strategy to improve DNA vaccination.

[Inhibition of extracts of ampelopsis sinica roots on DHBVsAg in sera of ducklings].

The ducklings, which are infected with Duck HBV to produce DHBVsAg in sera in advance, are treated with extracts from Ampelopsis sinica roots and some of them are treated with interferon alpha (INF) as positive control group. According the titer of DHBVsAg in Ducklings sera and the results of observing the tissues of the duckling's livers, it is demonstrated that the extracts of Ampelopsis sinica roots possess a certain action inhibiting DHBV and the action is enduring.

Microcytic anemia and changes in ferrokinetics as late after-effects of glucan administration in murine hepatitis virus-infected C57BL/10ScSnPh mice.

Mild microcytic anemia (without changes in mean corpuscular hemoglobin concentration, MCHC) was discovered 6-14 weeks after a single s.c. administration of 4 mg of particulate glucan to C57BL/10ScSnPh mice serologically positive for murine hepatitis (MHV). The anemia was associated with granulocytosis, decreased body weight and spleen hypertrophy. The overall intensity of erythropoiesis was measured by 59Fe-incorporation into the heme of erythropoietic organs. The localization of erythropoiesis became markedly redistributed--heme production was suppressed in the bone marrow while a several-fold increase was recorded for the spleen. A new steady state was also discovered in ferrokinetics: an iron pool localized away from the blood, erythropoietic organs and the liver was significantly elevated, and hypoferremia was detected. Anemia and wasting of mice were not observed in the same mouse strain free of MHV. A single administration of particulate glucan resulted in late impairment of red blood cell formation in the C57BL/10ScSnPh mouse strain infected with the mouse hepatitis virus. The anemia shares a number of features with those observed for the anemia of chronic diseases.

Mouse hepatitis virus and host determinants of vertical transmission and maternally-derived passive immunity in mice.

Transmission of mouse hepatitis virus (MHV) in utero following oronasal inoculation of pregnant mice was found to depend upon MHV strain and host genotype. Virulent, polytropic MHV-JHM was recovered from multiple maternal tissues, including liver and uterus, as well as placenta and fetus in susceptible BALB/cByJ mice. Fetuses were infected during all 3 trimesters of pregnancy. Low virulence, polytropic MHV-S infected fetuses in a low percentage of susceptible BALB/cByJ dams. Infection of resistant CD-1 mice with MHV-JHM was limited, with no fetal infection. Enterotropic MHV-Y was largely restricted to intestine of BALB/cByJ and CD-1 dams, with minimal dissemination and no fetal infection. Maternally-derived MHV IgG antibody was detectable in pup sera through 4 weeks of age. Antibody titers were generally lower in second litters of the same dam. Cross-fostering experiments showed that antibody was transferred via colostrum and not in utero, and that pups were capable of absorption through 2 weeks of age. Pups nursing immune dams were protected against MHV challenge at 1 and 2 weeks of age, compared to pups nursing naive dams. Immunity to MHV challenge was cross-protective against both antigenically homotypic and heterotypic strains of MHV.

Effects of an extract from Phyllanthus niruri on hepatitis B and woodchuck hepatitis viruses: in vitro and in vivo studies.

An aqueous extract of the plant Phyllanthus niruri inhibits endogenous DNA polymerase of hepatitis B virus and binds to the surface antigen of hepatitis B virus in vitro. The extract also inhibits woodchuck hepatitis virus (WHV) DNA polymerase and binds to the surface antigen of WHV in vitro. The extract, nontoxic to mice, was tested for antiviral activity in woodchucks (Marmota monax). In a trial using six long-term WHV-carrier woodchucks, five treated animals showed a faster decrease in woodchuck hepatitis virus surface antigen titer compared to one untreated control. In animals recently infected with WHV, the extract was effective when administered i.p. in three out of four animals in reducing and within 3-6 weeks eliminating both the surface antigen titer and DNA polymerase activity in serum. The treatment was discontinued after 10 weeks, and the treated animals have remained free of detectable markers of WHV for more than 45 weeks. In contrast, three untreated controls remained positive for both markers for WHV. One of the controls died after 8 weeks; the other two controls have remained positive for WHV markers for more than 45 weeks. In a third trial with long-term carriers, test animals treated subcutaneously with the extract for 12 weeks did not respond; but on switching the mode of administration to i.p., two out of the five animals showed a significant decrease in woodchuck hepatitis virus surface antigen titer compared to controls.