Comparison between chronic hepatitis B patients with untreated immune-tolerant phase vs. those with virological response by antivirals

Routine nucleos(t)ide analogs (NUCs) have not yet been recommended for patients with immune-tolerant (IT) phase in chronic hepatitis B virus (HBV) infection. We aimed to evaluate prognosis of patients in untreated IT-phase (UIT group), compared to those in immune-active phase who achieved virological response by NUCs according to guidelines (VR group). Between 2006 and 2012, patients in UIT or VR groups were included. Cumulative risks of HCC and liver-related events (LREs) development were assessed. Furthermore, propensity-score was calculated based upon age, gender, diabetes and liver stiffness. UIT group (n = 126) showed younger age, lower proportion of male gender and lower LS than VR group (n = 641). UIT group had similar 10-year cumulative risks of HCC (2.7% vs. 2.9%, p = 0.704) and LRE (4.6% vs. 6.1%, p = 0.903) development, compared to VR group. When we re-defined UIT group by the lower ALT cut-offs, 10-year cumulative risks of HCC and LRE development were 2.9% and 4.8%, respectively. Using propensity-score matching and inverse probability treatment weighting analysis, similar results were reproduced. UIT group consistently had similar prognosis compared to VR group. Therefore, further large-scale prospective studies in order to verify rationales of routine NUCs in UIT group are still required.

miRNA-548ah promotes the replication and expression of hepatitis B virus by targeting histone deacetylase 4

AIM

Many studies have shown that some microRNAs (miRNAs) play an important role in the pathogenesis of chronic hepatitis B (CHB) infection. In this study, we aimed to explore the role and molecular mechanism of miRNA-548ah in the replication and expression of the hepatitis B virus (HBV).

MAIN METHODS

Overexpression and knockdown of miRNA-548ah were performed in three hepatoma cell lines with HBV replication and in a murine HBV model injected with adenovirus HBV vector. The effect of miRNA-548ah on its target gene, histone deacetylase (HDAC) 4, were confirmed in in vitro studies and further investigated in liver tissues from CHB patients.

KEY FINDINGS

miRNA-548ah significantly increased the expression of HBV in hepatoma cell lines and in a HBV mouse model. The expression level of covalently closed circular DNA (cccDNA) in the miRNA-548ah mimics group was significantly higher than the negative control group and significantly lower in the miRNA-548ah inhibitor group. The HBV core antigen promotes the expression of miRNA-548ah in hepatocytes. Finally, we observed a negative correlation between the expression of miRNA-548ah and HDAC4 in the liver tissue of patients with CHB.

SIGNIFICANCE

miRNA-548ah promoted the replication and expression of HBV through the regulation of the target gene, HDAC4. Inhibition of HDAC4 by miRNA-548ah might influence the deacetylation state of histones binding to cccDNA, thereby enhancing the replication of cccDNA. The HBV core antigen might increase the expression of miRNA-548ah. These results may provide new potential molecular targets for the prevention and treatment of CHB.

HBeAg induces the expression of macrophage miR-155 to accelerate liver injury via promoting production of inflammatory cytokines

Activation of Kupffer cells (KCs) induced that inflammatory cytokine production plays a central role in the pathogenesis of HBV infection. The previous studies from our and other laboratory demonstrated miRNAs can regulate TLR-inducing inflammatory responses to macrophage. However, the involvement of miRNAs in HBV-associated antigen-induced macrophage activation is still not thoroughly understood. Here, we evaluated the effects and mechanisms of miR-155 in HBV-associated antigen-induced macrophage activation. First, co-culture assay of HepG2 or HepG2.2.15 cells and RAW264.7 macrophages showed that HepG2.2.15 cells could significantly promote macrophages to produce inflammatory cytokines. Furthermore, we, respectively, stimulated RAW264.7 macrophages, mouse primary peritoneal macrophages, or healthy human peripheral blood monocytes with HBV-associated antigens, including HBcAg, HBeAg, and HBsAg, and found that only HBeAg could steadily enhance the production of inflammatory cytokines in these cells. Subsequently, miRNAs sequencing presented the up- or down-regulated expression of multiple miRNAs in HBeAg-stimulated RAW264.7 cells. In addition, we verified the expression of miR-155 and its precursors BIC gene with q-PCR in the system of co-culture or HBeAg-stimulated macrophages. Meanwhile, the increased miR-155 expression was positively correlation with serum ALT, AST, and HBeAg levels in AHB patients. Although MAPK, PI3K, and NF-κB signal pathways were all activated during HBeAg treatment, only PI3K and NF-κB pathways were involved in miR-155 expression induced by HBeAg stimulation. Consistently, miR-155 over-expression inhibited production of inflammatory cytokines, which could be reversed by knocking down miR-155. Moreover, we demonstrated that miR-155 regulated HBeAg-induced cytokine production by targeting BCL-6, SHIP-1, and SOCS-1. In conclusion, our data revealed that HBeAg augments the expression of miR-155 in macrophages via PI3K and NF-κB signal pathway and the increased miR-155 promotes HBeAg-induced inflammatory cytokine production by inhibiting the expression of BCL-6, SHIP-1, and SOCS-1.

BCP/PC mutation prevalence and their association with HBV replication in HIV/HBV co-infected patients

The high prevalence (14.3%) of HIV/HBV co-infections reported in west China makes it necessary to screen concurrent HBV infection in HIV carriers. HBV B genotype was shown to be dominant in 54 cases of HIV/HBV co-infection, accounting for 81.48% of the total. The total drug resistance rate observed was 3.70%. A1762T, G1764A and G1896A mutations were common mutations identified in the BCP/PC region. However, the prevalence of the G1896A mutation was significantly high among the HBeAg negative HIV/HBV co-infected patients, and may be associated with high HBV replication. Mutations in the PC region are related to the loss in synthesis of HBeAg and may accelerate HBV replication in HIV positive patients.

Discovery of Oxime Ethers as Hepatitis B Virus (HBV) Inhibitors by Docking, Screening and In Vitro Investigation

A series of oxime ethers with C₆-C₄ fragment was designed and virtually bioactively screened by docking with a target, then provided by a Friedel–Crafts reaction, esterification (or amidation), and oximation from p-substituted phenyl derivatives (Methylbenzene, Methoxybenzene, Chlorobenzene). Anti-hepatitis B virus (HBV) activities of all synthesized compounds were evaluated with HepG2.2.15 cells in vitro. Results showed that most of compounds exhibited low cytotoxicity on HepG2.2.15 cells and significant inhibition on the secretion of HBsAg and HBeAg. Among them, compound 5c-1 showed the most potent activity on inhibiting HBsAg secretion (IC₅₀ = 39.93 μM, SI = 28.51). Results of the bioactive screening showed that stronger the compounds bound to target human leukocyte antigen A protein in docking, the more active they were in anti-HBV activities in vitro.

Curcumin inhibits hepatitis B virus infection by down-regulating cccDNA-bound histone acetylation

AIM

To investigate the potential effect of curcumin on hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and the underlying mechanism.

METHODS

A HepG2.2.15 cell line stably transfected with HBV was treated with curcumin, and HBV surface antigen (HBsAg) and e antigen (HBeAg) expression levels were assessed by ELISA. Intracellular HBV DNA replication intermediates and cccDNA were detected by Southern blot and real-time PCR, respectively. The acetylation levels of histones H3 and H4 were measured by Western blot. H3/H4-bound cccDNA was detected by chromatin immunoprecipitation (ChIP) assays. The deacetylase inhibitors trichostatin A and sodium butyrate were used to study the mechanism of action for curcumin. Additionally, short interfering RNAs (siRNAs) targeting HBV were tested along with curcumin.

RESULTS

Curcumin treatment led to time- and dose-dependent reductions in HBsAg and HBeAg expression and significant reductions in intracellular HBV DNA replication intermediates and HBV cccDNA. After treatment with 20 μmol/L curcumin for 2 d, HBsAg and cccDNA levels in HepG2.2.15 cells were reduced by up to 57.7% (P < 0.01) and 75.5% (P < 0.01), respectively, compared with levels in non-treated cells. Meanwhile, time- and dose-dependent reductions in the histone H3 acetylation levels were also detected upon treatment with curcumin, accompanied by reductions in H3- and H4-bound cccDNA. Furthermore, the deacetylase inhibitors trichostatin A and sodium butyrate could block the effects of curcumin. Additionally, transfection of siRNAs targeting HBV enhanced the inhibitory effects of curcumin.

CONCLUSION

Curcumin inhibits HBV gene replication via down-regulation of cccDNA-bound histone acetylation and has the potential to be developed as a cccDNA-targeting antiviral agent for hepatitis B.

miR-29a promotes hepatitis B virus replication and expression by targeting SMARCE1 in hepatoma carcinoma

AIM

To investigate the functional role and underlying molecular mechanism of miR-29a in hepatitis B virus (HBV) expression and replication.

METHODS

The levels of miR-29a and SMARCE1 in HBV-infected HepG2.2.15 cells were measured by quantitative real-time PCR and western blot analysis. HBV DNA replication was measured by quantitative PCR and Southern blot analysis. The relative levels of hepatitis B surface antigen and hepatitis B e antigen were detected by enzyme-linked immunosorbent assay. The Cell Counting Kit-8 (CCK-8) was used to detect the viability of HepG2.2.15 cells. The relationship between miR-29a and SMARCE1 were identified by target prediction and luciferase reporter analysis.

RESULTS

miR-29a promoted HBV replication and expression, while SMARCE1 repressed HBV replication and expression. Cell viability detection indicated that miR-29a transfection had no adverse effect on the host cells. Moreover, SMARCE1 was identified and validated to be a functional target of miR-29a. Furthermore, restored expression of SMARCE1 could relieve the increased HBV replication and expression caused by miR-29a overexpression.

CONCLUSION

miR-29a promotes HBV replication and expression through regulating SMARCE1. As a potential regulator of HBV replication and expression, miR-29a could be a promising therapeutic target for patients with HBV infection.

KNK437 Inhibits Replication and Transcription of the Hepatitis B Virus

During replication of the hepatitis B virus (HBV) in liver cells, the reverse transcription of pre-genomic RNA (pgRNA) is initiated by protein priming at an RNA packaging signal ε located near the 5' end of pgRNA. Heat-shock proteins (Hsps) such as Hsc70, Hsp40, and Hsp90 have been reported to be involved in the reconstitution of HBV polymerase (P protein) and E. The P - E complex initiates the reverse transcription and assembly of nucleocapsids. Hence, blockade of P - ε interactions is an attractive target for drug intervention. We explored the influence of the Hsp inhibitor KNK437 on replication and transcription of the HBV. Three working models were applied: HepG2. 2. 15 cell line; Huh7 cells transfected transiently with the 1. 05 X HBV (pCH9-3091) plasmid; Huh7 cells transfected transiently with the 1. 3 X HBV (pGEM-1. 3 X HBV) plasmid. Cytotoxic effects of KNK437 were detected by the CCK-8 method. Levels of hepatitis B surface antigen (HBsAg) and hepatitis B viral protein (HBeAg) in the media secreted from cells were measured using an ELISA. Intracellular HBV DNAs within nucleocapsids were measured by quantitative polymerase chain reaction (qPCR), and intracellular HBV RNAs by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Transcription of Hsps in cells was determined by qRT-PCR. Data suggested that KNK437 reduced the extracellular secretion of HBsAg and HBeAg in most cases; it downregulated expression of intracellular HBV DNAs within nucleocapsids and RNA transcripts. The lowest rate of viral DNAs in KNK437-treated hepatocytes for all experimental groups was ~1. 5%o (control, 100%), whereas that for RNAs was ~30%. Western blotting revealed KNK437 to inhibit intracellular core expression in HepG2. 2. 15. As a general inhibitor, KNK437 suppressed transcription of hsp70, hsp90b, and hsp4o. These data suggest that KNK437 may be a potent anti-HBV inhibitor for future therapy against chronic hepatitis.

Hepatitis B virus upregulates host expression of α-1,2-mannosidases via the PPARα pathway

AIM

To assess the effects of hepatitis B virus (HBV) on the expression of host α-1,2-mannosidases and determine the underlying mechanisms.

METHODS

We measured the expression levels of MAN1A1, MAN1A2, MAN1B1, and MAN1C1 in cell lines HepG2.2.15, HepN10, HepAD38 and HepG2 by Western blot. Viral antigens (HBsAg and HBeAg) in the culture medium were measured using the chemiluminescence method. HBV DNA quantification assays were performed using a commercial real-time PCR kit. Protein levels of human liver tissue α-1,2-mannosidases were also evaluated by Western blot. Plasmids containing seven individual viral genes of HBV (PTT22-HBx, PTT22-HBs, PTT22-preS2, PTT22-preS1, PTT22-HBc, PTT22-HBe, and PTT22-HBp) or control plasmids (PTT22-vector) were transfected into HepG2 cells. MK886 (PPARα) and GW9662 (PPARγ) inhibitors were used to explore the effects of HBV on α-1,2-mannosidase expression after the PPARα and PPARγ pathways were blocked.

RESULTS

We showed that the expression of α-1,2-mannosidases was higher in stably transfected HBV cells than in controls. The expression levels of α-1,2-mannosidase were higher in AD38 cells than those in ND10 cells, which were in turn greater than those in G2.2.15 cells, and positively correlated with the expression of HBsAg in all the cell lines. Levels of α-1,2-mannosidase in non-tumorous liver tissues of HBV-related HCC patients were also higher than in the tissues from non-HBV-related HCC patients. Moreover, transfecting HepG2 cells with a component of the HBV viral envelope also increased the expression of α-1,2-mannosidases. However, this envelope protein component could not induce MAN1C1 expression in the presence of a PPARα inhibitor, MK886. We also found that MK886 did not affect the expression of MAN1C1 in AD38 cells without tetracycline in the culture medium. This phenomenon was not observed in the case of GW9662.

CONCLUSION

Our results indicate that HBV increases the expression of α-mannosidases both in vitro and in vivo via activation of the PPARα pathway by its envelope protein.

[Design, virtual screening, synthesis and anti-hepatitis B virus of oxime derivatives]

A series of new oxime and oxime ethers compounds were designed and virtually screened with target using the Molecular Operating Environment（MOE） software. Twelve unreported compounds including 4 oximes and 8 oxime ethers were synthesized with benzene, toluene, methoxybenzene and chlorobenzene as initial raw materials. Structures of compounds were elucidated by 1H NMR, 13C NMR and MS. The results of bioactive screening showed that a part of compounds displayed obviously anti-HBV activities. Inhibitory activities of compounds 4B-2 in secretion of HBsAg and HBeAg were IC50 HBsAg= 81.15 μmol·L-1, SIHBsAg = 9.20 and IC50 HBeAg = 90.66 μmol·L-1, SIHBeAg = 8.24, respectively. Preliminary structure-activity relationship study shows that methyl oxime ethers displayed better anti-HBV activities than the oximes.

Hepatitis B e antigen and its precursors promote the progress of hepatocellular carcinoma by interacting with NUMB and decreasing p53 activity

Hepatitis B viral infection is one of the leading causes of hepatocellular carcinoma (HCC) worldwide. Although several viral factors have been identified that may increase the risk for HCC development, the molecular mechanisms leading to the transformation of normal hepatocytes into cancer cells remain elusive. In this study, we demonstrated that the intracellular hepatitis B e antigen (HBeAg) and its precore precursors, but not their homologous core protein, could associate with NUMB and thereby impair the stability and transcriptional activity of tumor suppressor p53. HBeAg and its precursors could disrupt p53-NUMB and HDM2-NUMB interactions and tricomplex p53-HDM2-NUMB formation, inhibit the acetylation and translocation of p53 from cytosol to the nucleus, promote HDM2-mediated ubiquitination and degradation of p53, and suppress p53-dependent apoptosis. A xenograft tumorigenicity assay showed that expression of HBeAg and its precursors promoted carcinogenesis in a mouse model. Immunohistochemical analysis of the bioptic liver samples of HCC patients revealed that HBeAg positivity was associated with reduced transcriptional activity of p53. Taken together, the results suggest a role of intracellular HBeAg and its precursors in HCC development.

CONCLUSION

HBeAg and its precursors promote HDM2-mediated degradation and impair transcriptional activity of p53 by interacting with NUMB, consequently contributing to HCC development. (Hepatology 2016;64:390-404).

Hepatitis B virus antigens impair NK cell function

An inadequate immune response of the host is thought to be a critical factor causing chronic hepatitis B virus (CHB) infection. Natural killer (NK) cells, as one of the key players in the eradication and control of viral infections, were functionally impaired in CHB patients, which might contribute to viral persistence. Here, we reported that HBV antigens HBsAg and HBeAg directly inhibited NK cell function. HBsAg and/or HBeAg blocked NK cell activation, cytokine production and cytotoxic granule release in human NK cell-line NK-92 cells, which might be related to the downregulation of activating receptors and upregulation of inhibitory receptor. Furthermore, the underlying mechanisms likely involved the suppression of STAT1, NF-κB and p38 MAPK pathways. These findings implicated that HBV antigen-mediated inhibition of NK cells might be an efficient strategy for HBV evasion, targeting the early antiviral responses mediated by NK cells and resulting in the establishment of chronic virus infection. Therefore, this study revealed the relationship between viral antigens and human immune function, especially a potential important interaction between HBV and innate immune responses.

A Scorpion Defensin BmKDfsin4 Inhibits Hepatitis B Virus Replication in Vitro

Hepatitis B virus (HBV) infection is a major worldwide health problem which can cause acute and chronic hepatitis and can significantly increase the risk of liver cirrhosis and primary hepatocellular carcinoma (HCC). Nowadays, clinical therapies of HBV infection still mainly rely on nucleotide analogs and interferons, the usage of which is limited by drug-resistant mutation or side effects. Defensins had been reported to effectively inhibit the proliferation of bacteria, fungi, parasites and viruses. Here, we screened the anti-HBV activity of 25 scorpion-derived peptides most recently characterized by our group. Through evaluating anti-HBV activity and cytotoxicity, we found that BmKDfsin4, a scorpion defensin with antibacterial and Kv1.3-blocking activities, has a comparable high inhibitory rate of both HBeAg and HBsAg in HepG2.2.15 culture medium and low cytotoxicity to HepG2.2.15. Then, our experimental results further showed that BmKDfsin4 can dose-dependently decrease the production of HBV DNA and HBV viral proteins in both culture medium and cell lysate. Interestingly, BmKDfsin4 exerted high serum stability. Together, this study indicates that the scorpion defensin BmKDfsin4 also has inhibitory activity against HBV replication along with its antibacterial and potassium ion channel Kv1.3-blocking activities, which shows that BmKDfsin4 is a uniquely multifunctional defensin molecule. Our work also provides a good molecule material which will be used to investigate the link or relationship of its antiviral, antibacterial and ion channel–modulating activities in the future.

Cost-effectiveness analysis of antiviral therapies for hepatitis B e antigen-positive chronic hepatitis B patients in China

BACKGROUND AND OBJECTIVE

Several antiviral therapies are now available for patients with chronic hepatitis B (CHB), but the most cost-effective strategy for Chinese patients is unclear. The aim of this study was to estimate the long-term cost effectiveness of the antiviral treatments (lamivudine, adefovir, telbivudine and entecavir) for hepatitis B e antigen (HBeAg)-positive CHB patients in China.

METHODS

A Markov model was used to simulate the life-time (41-year time span) costs and effectiveness associated with antiviral treatments from the perspective of Chinese healthcare. Relative model parameters were derived from Chinese population studies. Costs and effectiveness were discounted at 5 %. The highest retail prices for generic and branded drug prices were also considered. Probabilistic sensitivity analysis and one-way sensitivity analysis were used to explore model uncertainties.

RESULTS

In the base-case analysis, the least quality-adjusted life years (QALYs) were obtained with adefovir as the reference strategy. Lamivudine generated the highest incremental cost-effectiveness ratio (ICER), with an additional US$35,000 needed to gain one additional QALY for generic drugs and US$36,000 for branded drugs. Entecavir had the lowest ICER of US$7,600 and US$9,100, respectively. The projected 10-year cumulative incidences of compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma (HCC) and mortality for entecavir were lower than the other strategies. In probabilistic sensitivity analyses, entecavir was the preferred option at a threshold of US$18,924 per QALY.

CONCLUSIONS

In patients with HBeAg-positive CHB in China, entecavir is a cost-effective option compared with other therapies for CHB.

Study on Post-Treatment Relapse in HBeAg Positive CHB Patients

BACKGROUND

Many factors are associated with post-treatment relapse in CHB patients, and there are no effective factors to predict relapse. In this study, we investigate the influence factors associated with post-treatment relapse and their predictive value in HBeAg positive CHB (eP-CHB).

METHODS

The factors associated with post-treatment relapse were analyzed firstly by a retrospective study in eP-CHB. Variables included age, sex, regimen, baseline HBeAg and HBV DNA level, total course of treatment as well as duration of consolidation therapy after HBeAg seroconversion. The predictive effects of the influence factors were evaluated in an eP-CHB prospective cohort.

RESULTS

89 patients were enrolled in the retrospective study, 42(47.2%) relapsed after discontinuation of treatment. Factors related to post-treatment relapse were total course of treatment, duration of consolidation therapy and baseline HBV DNA level. Relapse rates in patients with total course >36 months, consolidation duration >12 months and baseline HBV DNA level < 1.0E+5IU/ml were lower than those of total course <24 months (P = 0.002), consolidation duration≤12 months (P = 0.011) and baseline HBV DNA level > 1.0E+7IU/ml (P = 0.01) respectively. Patients with HBV DNA≥1.0E+7IU/ml plus HBeAg<200COI at baseline had the highest relapse rate and cumulative relapse rate than the other three arms (P = 0.048 and 0.008 respectively). Logistic regression analysis demonstrated that baseline HBV DNA level, duration of consolidation therapy and combination of baseline HBV DNA and HBeAg (IgDNA/IgHBeAg) were independent factors to predict post-treatment relapse. The model based on baseline IgDNA/IgHBeAg and consolidation duration worked well in predicting post-treatment relapse in the prospective study and the accuracy, specificity, sensitivity, PPV and NPV for prediction were 80.3%, 81.1%, 79.2%, 73.1% and 85.7% respectively.

CONCLUSIONS

Virological factors including baseline HBV DNA, HBeAg and treatment course were major influence factors associated with post-treatment relapse in eP-CHB. Patients with higher HBV DNA and lower HBeAg levels at baseline, shorter total course as well as consolidation therapy were more likely to develop relapse after discontinuation of therapy. The antiviral therapy in eP-CHB patients should be individually managed at different levels. It is better to treat those with higher viral load and lower HBeAg levels at baseline for a longer course, especially longer consolidation duration so as to decrease the relapse rate.

Inhibition of hepatitis B virus cccDNA by siRNA in transgenic mice

The elimination of viral covalently closed circular DNA (cccDNA) from the nucleus of infected hepatocytes is an obstacle to achieving sustained viral clearance during antiviral therapy of chronic hepatitis B virus (HBV) infection. The aim of our study was to determine whether treatment with siRNA is able to suppress viral cccDNA amplification using a HBV-transgenic mice model. The experimental results revealed that siRNAs can serve as efficient alternative anti-HBV agents, because they showed better inhibitory effect on viral replication and antigen expression in transgenic mice. More importantly, the siRNA markedly inhibited HBV cccDNA amplification.

Substitution at rt269 in Hepatitis B Virus Polymerase Is a Compensatory Mutation Associated with Multi-Drug Resistance

The emergence of compensatory mutations in the polymerase gene of drug resistant hepatitis B virus (HBV) is associated with treatment failure. We previously identified a multi-drug resistant HBV mutant, which displayed resistance towards lamivudine (LMV), clevudine (CLV), and entecavir (ETV), along with a strong replication capacity. The aim of this study was to identify the previously unknown compensatory mutations, and to determine the clinical relevance of this mutation during antiviral therapy. In vitro mutagenesis, drug susceptibility assay, and molecular modeling studies were performed. The rtL269I substitution conferred 2- to 7-fold higher replication capacity in the wild-type (WT) or YMDD mutation backbone, regardless of drug treatment. The rtL269I substitution alone did not confer resistance to LMV, ETV, adefovir (ADV), or tenofovir (TDF). However, upon combination with YMDD mutation, the replication capacity under LMV or ETV treatment was enhanced by several folds. Molecular modeling studies suggested that the rtL269I substitution affects template binding, which may eventually lead to the enhanced activity of rtI269-HBV polymerase in both WT virus and YMDD mutant. The clinical relevance of the rtL269I substitution was validated by its emergence in association with YMDD mutation in chronic hepatitis B (CHB) patients with sub-optimal response or treatment failure to LMV or CLV. Our study suggests that substitution at rt269 in HBV polymerase is associated with multi-drug resistance, which may serve as a novel compensatory mutation for replication-defective multi-drug resistant HBV.

Dual gRNAs guided CRISPR/Cas9 system inhibits hepatitis B virus replication

AIM

To screen and investigate the effective gRNAs against hepatitis B virus (HBV) of genotypes A-D.

METHODS

A total of 15 gRNAs against HBV of genotypes A-D were designed. Eleven combinations of two above gRNAs (dual-gRNAs) covering the regulatory region of HBV were chosen. The efficiency of each gRNA and 11 dual-gRNAs on the suppression of HBV (genotypes A-D) replication was examined by the measurement of HBV surface antigen (HBsAg) or e antigen (HBeAg) in the culture supernatant. The destruction of HBV-expressing vector was examined in HuH7 cells co-transfected with dual-gRNAs and HBV-expressing vector using polymerase chain reaction (PCR) and sequencing method, and the destruction of cccDNA was examined in HepAD38 cells using KCl precipitation, plasmid-safe ATP-dependent DNase (PSAD) digestion, rolling circle amplification and quantitative PCR combined method. The cytotoxicity of these gRNAs was assessed by a mitochondrial tetrazolium assay.

RESULTS

All of gRNAs could significantly reduce HBsAg or HBeAg production in the culture supernatant, which was dependent on the region in which gRNA against. All of dual gRNAs could efficiently suppress HBsAg and/or HBeAg production for HBV of genotypes A-D, and the efficacy of dual gRNAs in suppressing HBsAg and/or HBeAg production was significantly increased when compared to the single gRNA used alone. Furthermore, by PCR direct sequencing we confirmed that these dual gRNAs could specifically destroy HBV expressing template by removing the fragment between the cleavage sites of the two used gRNAs. Most importantly, gRNA-5 and gRNA-12 combination not only could efficiently suppressing HBsAg and/or HBeAg production, but also destroy the cccDNA reservoirs in HepAD38 cells.

CONCLUSION

These results suggested that CRISPR/Cas9 system could efficiently destroy HBV expressing templates (genotypes A-D) without apparent cytotoxicity. It may be a potential approach for eradication of persistent HBV cccDNA in chronic HBV infection patients.

Anti-hepatitis B virus activities of friedelolactones from Viola diffusa Ging

BACKGROUND

Hepatitis B virus (HBV) infection is the major factor of causing hepatitis B, cirrhosis and liver cancer. Interferon and nucleoside drugs, the main drugs to treat HBV infection, have disadvantages of scavenge difficulty and drug resistance respectively. Viola diffusa Ging is used as a traditional Chinese herbal medicine for the treatment of hepatitis.

PURPOSE

The aim of the study is to investigate the chemical constituents of Viola diffusa Ging and their anti-HBV activity.

METHODS

Chemical constituents were extracted and purified by ethanol reflux extraction and chromatographic separation technology including D-101 Macroporous resin, silica gel, Sephadex LH-20 and preparative thin-layer chromatography. Their structures were elucidated on the basis of extensive NMR and MS data. Cytotoxicity and inhibiting effects on HBsAg and HBeAg secretion of HepG2.2.15 of all compounds except 10 were studied by MTT method and ELISA method.

RESULTS

Three friedelolactones with naturally occurring seco-ring-A friedelane triterpenoids, 2β-hydroxy-3, 4-seco-friedelolactone-27-oic acid (1), 2β, 28β-dihydroxy-3,4-seco-friedelolactone-27-oic acid (2) and 2β, 30β-dihydroxy-3,4-seco-friedelolactone-27-lactone (3), and a stigmastane, stigmast-25-ene-3β,5α,6β-triol (11) together with nine known compounds were isolated from the whole plant of Viola diffusa G. (Violaceae). Compounds 1-3, 9, 11, 12 exhibited significant activities of blocking both HBsAg and HBeAg secretion, and compound 4, 6, 7, 8 selectively inhibited HBeAg secretion while compound 13 selectively inhibited HBsAg secretion. IC50 values of compounds 1 and 2, 26.2 μM and 33.7 μM for HBsAg, 8.0 μM and 15.2 μM for HBeAg, was significantly lower than that of positive control lamivudine.

CONCLUSION

Compounds 1-3, 11 are new compounds never reported before and the promising results demonstrate the potential of compound 1-3, 9, 11, 12 for the treatment of HBV infection.

Hepatitis B e antigen status and hepatitis B DNA levels in women of childbearing age with chronic hepatitis B infection screening for clinical trials

BACKGROUND

Perinatal or mother-to-child transmission of hepatitis B virus (HBV) results in a high frequency of chronic infection. Risk of mother-to-child transmission is associated with maternal viral factors including hepatitis B e antigen (HBeAg) positivity and viral load.

AIM

To investigate associations between age, HBeAg status, HBV DNA levels and genotype in female patients screened for inclusion into two contemporary, randomized HBV trials.

METHODS

Retrospective analyses focused on differences between women of childbearing age (≤44 years) and older women. Female patients (N = 355; 18-69 years) were included in the analysis: 41.7% of patients were Asian. In total, 44.4% were HBeAg-positive.

RESULTS

Significantly more women aged ≤44 years were HBeAg-positive compared to women ≥45 years (57.2% versus 27.5%, respectively, p<0.0001), this proportion declined with increasing age. Younger women were significantly more likely to have high HBV viral load (HBV DNA>108 copies mL: ≤44 years 46.0% vs ≥45 years 25.5%, respectively; p<0.0001), and this declined with increasing age. HBeAg positivity was slightly higher in Asian women, associated with a higher proportion of HBV genotypes B and C in this population. There was no obvious relationship between genotype and viral load.

CONCLUSIONS

Women of childbearing age with CHB are more likely to have high HBV viral load and HBeAg positivity than older women; this likelihood decreases with age. Maternal serological and virological status should therefore be established early in pregnancy, taking into account age and genotype, and a risk-reducing strategy implemented in any patient who is HBeAg positive and has a high viral load.

Effect of Radix Trichosanthis and Trichosanthin on Hepatitis B Virus in HepG2.2.15 Cells

Radix Trichosanthis is a Chinese herbal medicine that has great medical value and pharmacological actions. There is already a long history of using the plant Radix Trichosanthis as treatment for hepatitis B virus in China. This research mainly focused on investigating the therapeutic effect of different extracts from Radix Trichosanthis on hepatitis B virus, on a cellular level (ex vivo). Cell survival rate of HepG2.2.15 cells was detected by MTT assay. HBsAg and HBeAg in HepG 2.2.15 cell supernatant were evaluated by enzyme linked immunosorbent assay (ELISA). Results showed that water extract from Radix Trichosanthis had a stronger inhibitive effect on expression of HBsAg and HBeAg in HepG2.2.15 cells than the alcohol extract from the same plant. Considering that the most active component of Radix Trichosanthis was in its aqueous extract and this might be related to the active component Trichosanthin. Trichosanthin was further used for related experiments to confirm this hypothesis. The results showed that Trichosanthin, in the aqueous extract from Radix Trichosanthis, is likely the main component responsible for the anti-hepatitis B viral effect.

S-phase arrest after vincristine treatment may promote hepatitis B virus replication

AIM: To observe the effect of vincristine on hepatitis B virus (HBV) replication in vitro and to study its possible mechanisms.

METHODS: Vincristine was added to the cultures of two cell lines stably expressing HBV. Then, the levels of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and hepatitis B core antigen (HBcAg) in the supernatants or cytoplasm were examined using by enzyme-linked immunosorbent assay and Western blot. The HBV pregenome RNA (pgRNA) was detected using reverse transcription-PCR and real-time fluorescent quantitative PCR (RT-qPCR), and viral DNA was detected using Southern blot and RT-qPCR. Cell proliferation after drug treatment was detected using the BrdU incorporation test and the trypan blue exclusion assay. Cell cycle and cell apoptosis were examined using flow cytometry and Western blot.

RESULTS: Vincristine up-regulated HBV replication directly in vitro in a dose-dependent manner, and 24-h exposure to 0.1 μmol/L vincristine induced more than 4-fold and 3-fold increases in intracellular HBV DNA and the secretion of viral DNA, respectively. The expression of HBV pgRNA, intracellular HBsAg and HBcAg, and the secretion of HBeAg were also increased significantly after drug treatment. Most importantly, vincristine promoted the cell excretion of HBV nucleocapsids instead of HBV Dane particles, and the nucleocapsids are closely related to the HBV pathogenesis. Furthermore, vincristine inhibited the proliferation of cells stably expressing HBV. The higher the concentration of the drug, the more significant the inhibition of the cell proliferation and the stronger the HBV replication ability in cells. Flow cytometry indicated that cell cycle arrest at S-phase was responsible for the cell proliferation inhibition.

CONCLUSION: Vincristine has a strong stimulatory effect on HBV replication and induces cell cycle arrest, and cell proliferation inhibition may be conducive to viral replication.

Association of IL28B polymorphisms with peginterferon treatment response in Chinese Han patients with HBeAg-positive chronic hepatitis B

AIMS

To investigate whether IL28B polymorphisms could affect the treatment response to peginterferon alpha (PEG-IFN) in chronic hepatitis B (CHB) patients in the Chinese Han population.

METHODS

A total of 212 hepatitis B e antigen (HBeAg)-positive patients treated with PEG-IFN monotherapy were enrolled in this study. Genotype analysis was performed for IL28B rs12980275, rs12979860 and rs8099917 using the MassArray system. Response was defined as cases showing normal aminotransferase (ALT) levels, HBV DNA level < 200 IU/ml and HBeAg seroconversion after 48 weeks of PEG-IFN therapy.

RESULTS

The patients were infected with hepatitis B virus (HBV) genotype B (44.8%) and C (55.2%) with a total response rate of 34.9%. For the three SNPs, there were significant differences between the response (R) and non-response (NR) groups both in allele frequencies and genotype distributions. IL28B genotype was independently associated with R for AA vs. N-AA (OR 2.70, 95% CL 1.21-6.01; P = 0.015) at rs12980275 after adjustment for sex, age, HBV genotype, baseline levels of HBV DNA and ALT. There were similar results for rs12979860 CC vs. N-CC (OR 2.56, 95% CL 1.15-5.67; P = 0.021) and rs8099917 TT vs. N-TT (OR 2.80, 95% CL 1.23-6.39; P = 0.015) respectively. Furthermore, one block formed by rs12980275 and rs12979860 was identified in this study. In multivariate analyses, the most common haplotype A-C was independently associated with high rates of R (OR 2.53, 95% CL 1.20-5.34; P = 0.015).

CONCLUSIONS

Our study suggested that genetic variations in IL28B may play a critical role in PEG-IFN efficacy in HBeAg-positive CHB patients in Han Chinese.

In vitro and in vivo anti-hepatitis B virus activities of the lignan niranthin isolated from Phyllanthus niruri L

ETHNOPHARMACOLOGICAL RELEVANCE

Niranthin is a lignan isolated from Phyllanthus niruri L. This plant has long been used in folk medicine for liver protection and antihepatitis B in many Asian countries. This study was designed to evaluate the anti-hepatitis B virus activity of niranthin using HepG2.2.15 cells and duck hepatitis B virus (DHBV) infected ducks as in vitro and in vivo models.

MATERIALS AND METHODS

Niranthin was isolated from Phyllanthus niruri L. (Euphorbiaceae) by extraction and chromatographic procedures and the anti-hepatitis B virus activity was evaluated both in vitro and in vivo. The human HBV-transfected liver cell line HepG2.2.15 was used in vitro assay. And the in vivo anti-hepatitis B virus activity was evaluated on the expression of HBV replication, HBsAg, HBeAg, ALT and AST on day 0, 7, 14, 17 after niranthin was dosed intragastricly (i.g.) once a day for 14 days at the dosages of 25, 50 and 100 mg/kg/day in the duck hepatitis B virus (DHBV) infected ducks.

RESULTS

In the human HBV-transfected liver cell line HepG2.2.15, the secretion of HBsAg and HBeAg were significantly decreased after treatment with niranthin for 144 h, with IC50 values for HBsAg of 15.6 µM, IC50 values for HBeAg of 25.1 µM. In DHBV-infected ducklings, niranthin significantly reduced the serum DHBV DNA, HBsAg, HBeAg, ALT and AST. Furthermore, analysis of the liver pathological changes confirmed the hepatoprotective effect of niranthin.

CONCLUSION

The experimental data demonstrated that niranthin exhibits anti-hepatitis B virus activity both in vitro and in vivo.