[Effect of Notch signaling on the activation of hepatic stellate cells].

OBJECTIVE: To investigate whether Notch signaling is activated in hepatic stellate cells (HSCs), and to determine whether manipulation of the Notch signaling pathway can effect the activation of HSCs. METHODS: The expression of Notch signaling components in unactivated or TGF-b1-activated HSC-T6 cells was detected by Taqman Probe-based gene expression analysis. Differential expression of Notch3 and Jagged1 was detected by immunofluorescence analysis. Notch3-mediated expression of the myofibroblastic markers, a-SMA and collagen I, was detected in HSC-T6 cells transfected with pcDNA3.1-N3ICD or Notch3 siRNA by Western blotting. RESULTS: Notch signaling components were expressed in both unactivated and activated HSC-T6 cells, but the TGF-b1-treated cells showed significantly higher expression levels of Jagged1 (3.9-fold, F = 2543.482), Notch3 (4.2-fold, F = 287.982), and HES1 (3.2-fold, F = 1719.851). Transfection-mediated over-expression of Notch3 led to significantly increased expression of a-SMA (6.8-fold, t = 13.157) and collagen I (5.5-fold, t = 9.810) (both P less than 0.01). Transient knock-down of Notch3 expression by siRNA decreased expression of the myofibroblastic markers (a-SMA by approximately 90%, t = 19.863 and collagen I by 84%, t = 10.376; both, P less than 0.01). Moreover, knock-down of Notch3 antagonized the TGF-b1-induced expression of a-SMA and collagen I. CONCLUSION: Notch signaling may participate in liver fibrogenesis by regulating HSC activation. Selective interruption of Notch3 may represent a new anti-fibrotic strategy to treat liver fibrosis.

[Enhancement of antiviral immunity in HBV mouse model by blocking PD-1/PD-L1 signaling pathway].

OBJECTIVE: To establish a mouse model for human chronic HBV infection, and to investigate the role of PD-1/PD-L1 signaling pathway in antiviral immunity. METHODS: A mouse model was established by hydrodynamic injection of the plasmid pAAV/HBV1.2-GFP into the tail vein of C57BL/6 mice, HBV markers were assayed at different time points after injection. After intraperitoneal injection of anti-PD-L1 monoclonal antibody, the serum ALT, and HBV DNA in the serum, liver and kidney were assayed. RESULTS: The chronic HBV infection mouse model were established successfully, serum HBsAg and high load of HBV DNA were detectable 90 days after plasmid injection. After blocking of the PD-1/PD-L1 pathway, the serum ALT level of mice were significantly increased (P < 0.01), and the HBV DNA load in serum (P < 0.01), liver (P < 0.05) and kidney (P < 0.05) were decreased significantly. CONCLUSION: Blocking the PD-1/PD-L1 signaling pathway can enhance antiviral response in mice with chronic HBV infection.

Inhibition of hepatitis B virus replication by pokeweed antiviral protein in vitro.

AIM: To explore the inhibitory effects of pokeweed antiviral protein seed (PAP-S) and PAP encoded by a eukaryotic expression plasmid on hepatitis B virus (HBV) replication in vitro. METHODS: HepG2 2.2.15 cells in cultured medium were treated with different concentrations of PAP-S. HBsAg, HBeAg and HBV DNA in supernatants were determined by ELISA and fluorescent quantitative PCR respectively. MTT method was used to assay for cytotoxicity. HepG2 were cotransfected with various amounts of PAP encoded by a eukaryotic expression plasmid and replication competent wild-type HBV 1.3 fold over-length plasmid. On d 3 after transfection, HBsAg and HBeAg were determined by using ELISA. Levels of HBV core-associated DNA and RNA were detected by using Southern and Northern blot, respectively. RESULTS: The inhibitory effects of PAP-S on HBsAg, HBeAg and HBV DNA were gradually enhanced with the increase of PAP concentration. When the concentration of PAP-S was 10 mug/mL, the inhibition rates of HBsAg, HBeAg and HBV DNA were 20.9%, 30.2% and 50%, respectively. After transfection of 1.0 microg and 2.0 microg plasmid pXF3H-PAP, the levels of HBV nucleocapside-associated DNA were reduced by 38.0% and 74.0% respectively, the levels of HBsAg in the media by 76.8% and 99.7% respectively, and the levels of HBeAg by 72.7% and 99.3% respectively as compared with controls. Transfection with 2 mug plasmid pXF3H-PAP reduced the levels of HBV nucleocapside-associated RNA by 69.0%. CONCLUSION: Both PAP-S and PAP encoded by a eukaryotic expression plasmid could effectively inhibit HBV replication and antigen expression in vitro, and the inhibitory effects were dose-dependent.

Programmed death-1 expression is associated with the disease status in hepatitis B virus infection.

AIM: To define the potential role of programmed death-1/programmed death-ligand (PD-1/PD-L) pathway in different hepatitis B virus (HBV) infection disease status; we examined the expression of PD-1 on antigen specific CD8+ T cells in peripheral blood of patients with chronic hepatitis B (CHB) and acute exacerbation of hepatitis B (AEHB) infection. METHODS: The PD-1 level on CD8+ T lymphocytes and the number of HBV specific CD8+ T lymphocytes in patients and healthy controls (HCs) were analyzed by staining with pentameric peptide-human leukocyte antigen2 (HLA2) complexes combined with flow cytometry. Real-time quantitative polymerase chain reaction (PCR) was used to measure the serum HBV-DNA levels. RESULTS: The level of PD-1 expression on total CD8+ T cells in CHB patients (13.86% +/- 3.38%) was significantly higher than that in AEHB patients (6.80% +/- 2.19%, P < 0.01) and healthy individuals (4.63% +/- 1.23%, P < 0.01). Compared to AEHB patients (0.81% +/- 0.73%), lower frequency of HBV-specific CD8+ T cells was detected in chronic hepatitis B patients (0.37% +/- 0.43%, P < 0.05). There was an inverse correlation between the strength of HBV-specific CD8+ T-cell response and the level of PD-1 expression. Besides, there was a significant positive correlation between HBV viral load and the percentage of PD-1 expression on CD8+ T cells in CHB and AEHB subjects (R = 0.541, P < 0.01). However, PD-1 expression was not associated with disease flare-ups as indicated by alanine aminotransferase (ALT) levels (R = 0.066, P > 0.05). CONCLUSION: Our results confirm previous reports that HBV specific CD8+ T-cell response in the peripheral blood is more intense in patients with AEHB than in chronic hepatitis B with persistent viral infection. Moreover, there is a negative correlation between the level of PD-1 and the intensity of virus specific CD8+ T cell response.

Predictors for efficacy of combination therapy with a nucleos(t)ide analogue and interferon for chronic hepatitis B.

This study aims to explore the efficacy of interferon-α (IFN-α) combined with either entecavir (ETV) or adefovir (ADV) therapy versus IFN-α mono-therapy for chronic hepatitis B (CHB) patients, and to identify the factors associated with treatment outcomes. Totally, 159 CHB patients receiving interferon-based treatment for 48 weeks were enrolled in this retrospective study, including IFN-α mono-therapy group (group A, n=44), IFN-α plus ADV group (group B, n=53) and IFN-α plus ETV group (group C, n=62). The primary measures of efficacy assessments were the changes in HBsAg. Cox regression analysis was used to identify the predictors of treatment outcomes. The predictive values of the factors were assessed by ROC analysis. For patients with baseline hepatitis B surface antigen (HBsAg) level <1000 IU/mL, the reductions in mean HBsAg levels at week 48 were greater in group C than that in group A (P<0.05). Higher rate of HBeAg seroconversion was achieved in the combined therapy group than in IFN-α mono-therapy group at week 48 (P<0.05). Two factors were independently associated with HBeAg seroconversion: baseline HBeAg level <2.215 log10 index/mL and ΔHBeAg (decline in HBeAg from baseline) >0.175 log10 at week 12. In conclusion, interferon-α plus ETV therapy can accelerate HBsAg decline as compared with interferon-α mono-therapy in CHB patients with lower baseline HBsAg levels, and the combination therapy was superior to IFN-α mono-therapy in increasing the rate of HBeAg seroconversion. Baseline HBeAg and ΔHBeAg at week 12 can independently predict HBeAg seroconversion in patients subject to interferon-based therapy for 48 weeks.

Prdx1-encoded peroxiredoxin is important for vascular development in zebrafish.

Genetic signaling and redox homeostasis are required for proper growth of blood vessels. Here, we report a novel function of peroxiredoxin1 (Prdx1) in vascular development in zebrafish. Knockdown of prdx1 impairs the growth of intersegmental vessel and caudal vein plexus (CVP), and reduces the expression of vascular markers, thus suggesting a role for prdx1 in vasculature and indicating that the antioxidant function of prdx1 is important. We found that H2 O2 -treated embryos also have CVP defects and observed synergistic effects when prdx1 knockdown was combined with H2 O2 treatment. Moreover, N-acetyl-cysteine treatment rescues the vascular defects in prdx1 morphants. These results suggest that oxidative stress disturbs vascularization. Furthermore, we show that the regulation of prdx1 is mediated by Notch and BMP signals.

Analysis of prognosis on patients with severe viral hepatitis using the model for end-stage liver disease.

AIM: To study the practical use of the model for end-stage liver disease (MELD) on clinic and assess its validity by the concordance (C)-statistic in predicting the prognosis of the patient with severe viral hepatitis. METHODS: One hundred and twenty-one patients were divided into plasma exchange group and non-plasma exchange group, and were graded with MELD formula. The death rate was observed within 3 mo. RESULTS: Eighty-one patients died within 3 mo (35 cases in PE group, 46 cases in non-PE group). The mortality of patients in PE group whose MELD score between 20-30 and 30-40 were 31.6% and 57.7%, respectively, but in non-PE cases they were 67.6%, 81.3% respectively. There was significant difference between PE group and non-PE group (P<0.05). However, the mortality of patients whose MELD score higher than 40 were 93.3% in PE group and 100% in non-PE group and there was no significant difference between the two groups (P = 0.65>0.05). The optimal cut-off values of MELD to predict the prognosis of patients were 30 in PE group whose sensitivity, specificity and C-statistic were 80.0%, 52.0% and 0.777, but in non-PE group they were 25, 82.6%, 86.7% and 0.869, respectively. CONCLUSION: The MELD score can act as a disease severity index for patients with severe viral hepatitis, and the mortality of the patient increases with the increase of the MELD score. The MELD can accurately predict the short-term prognosis of patients with severe viral hepatitis.

Prognosis of acute-on-chronic liver failure patients treated with artificial liver support system.

AIM: To establish a new model for predicting survival in acute-on-chronic liver failure (ACLF) patients treated with an artificial liver support system. METHODS: One hundred and eighty-one ACLF patients who were admitted to the hospital from January 1, 2012 to December 31, 2014 and were treated with an artificial liver support system were enrolled in this retrospective study, including a derivation cohort (n = 113) and a validation cohort (n = 68). Laboratory parameters at baseline were analyzed and correlated with clinical outcome. In addition to standard medical therapy, ACLF patients underwent plasma exchange (PE) or plasma bilirubin adsorption (PBA) combined with plasma exchange. For the derivation cohort, Kaplan-Meier methods were used to estimate survival curves, and Cox regression was used in survival analysis to generate a prognostic model. The performance of the new model was tested in the validation cohort using a receiver-operator curve. RESULTS: The mean overall survival for the derivation cohort was 441 d (95%CI: 379-504 d), and the 90- and 270-d survival probabilities were 70.3% and 58.3%, respectively. The mean survival times of patients treated with PBA plus PE and patients treated with PE were 531 d (95%CI: 455-605 d) and 343 d (95%CI: 254-432 d), respectively, which were significantly different (P = 0.012). When variables with bivariate significance were selected for inclusion into the multivariate Cox regression model, number of complications, age, scores of the model for end-stage liver disease (MELD) and type of artificial liver support system were defined as independent risk factors for survival in ACLF patients. This new prognostic model could accurately discriminate the outcome of patients with different scores in this cohort (P < 0.001). The model also had the ability to assign a predicted survival probability for individual patients. In the validation cohort, the new model remained better than the MELD. CONCLUSION: A novel model was constructed to predict prognosis and accurately discriminate survival in ACLF patients treated with an artificial liver support system.

Recombinant adeno-associated virus-mediated transfer of shRNA against Notch3 ameliorates hepatic fibrosis in rats.

Liver fibrosis, a wound healing process following all kinds of liver injuries, is characterized by excessive deposition of extracellular matrix (ECM). Our previous study revealed that Notch3 might participate in liver fibrogenesis by regulating the activation of hepatic stellate cells (HSCs). The aim of this study was to assess the effects of Notch3 shRNA on hepatic fibrosis in a rat model induced by carbon tetrachloride (CCl4) and to clarify the mechanisms underlying those effects. Recombinant adeno-associated virus type 1 (rAAV1) vector carrying Notch3 shRNA (rAAV1-Notch3-shRNA) was generated and transferred to rat livers via the tail vein. The expression of Notch3, Jagged1, Hes1 and α-SMA were detected by real-time RT-PCR and immunofluorescence. The effects of rAAV1-Notch3-shRNA on fibrosis was investigated by pathological and immunohistochemical examination. Our findings showed that Notch3, Jagged1, Hes1 and α-SMA were downregulated. This downregulation was accompanied by improved hepatic fibrosis after the inhibition of Notch3 in vivo. rAAV1-Notch3-shRNA treatment reversed the epithelial-mesenchymal transition (EMT) in fibrotic livers by decreasing the expression of transforming growth factor ß1 (TGF-ß1) and vimentin in a line with the increased expression of E-cadherin. The inhibition of Notch3 was not found to play a role in hepatocyte proliferation. Rather, it inhibited hepatocyte apoptosis in vivo to some extent. The results of the present study suggest that the inhibition of Notch3 can protect hepatocytes from undergoing apoptosis and attenuate liver fibrogenesis. This may be a viable therapeutic option for hepatic fibrosis.

Notch3 regulates the activation of hepatic stellate cells.

AIM: To investigate whether Notch signaling is involved in liver fibrosis by regulating the activation of hepatic stellate cells (HSCs). METHODS: Immunohistochemistry was used to detect the expression of Notch3 in fibrotic liver tissues of patients with chronic active hepatitis. The expression of Notch3 in HSC-T6 cells treated or not with transforming growth factor (TGF)-ß1 was analyzed by immunofluorescence staining. The expression of Notch3 and myofibroblastic marker α-smooth muscle actin (α-SMA) and collagen I in HSC-T6 cells transfected with pcDNA3.1-N3ICD or control vector were detected by Western blotting and immunofluorescence staining. Moreover, effects of Notch3 knockdown in HSC-T6 by Notch3 siRNA were investigated by Western blotting and immunofluorescence staining. RESULTS: The expression of Notch3 was significantly up-regulated in fibrotic liver tissues of patients with chronic active hepatitis, but not detected in normal liver tissues. Active Notch signaling was found in HSC-T6 cells. TGF-ß1 treatment led to up-regulation of Notch3 expression in HSC-T6 cells, and over-expression of Notch3 increased the expression of α-SMA and collagen I in HSC-T6 without TGF-ß1 treatment. Interestingly, transient knockdown of Notch3 decreased the expression of myofibroblastic marker and antagonized TGF-ß1-induced expression of α-SMA and collagen I in HSC-T6. CONCLUSION: Notch3 may regulate the activation of HSCs, and the selective interruption of Notch3 may provide an anti-fibrotic strategy in hepatic fibrosis.