scholarly journals Anti-Hepatitis B Virus Effect and Possible Mechanism of Action of 3,4-O-Dicaffeoylquinic AcidIn VitroandIn Vivo

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Yi-Hang Wu ◽  
Bing-Jie Hao ◽  
Hong-Cui Cao ◽  
Wei Xu ◽  
Yong-Jun Li ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Transgenic Mice ◽  
Core Protein ◽  
Heme Oxygenase 1 ◽  
Test Compound ◽  
Hbv Cccdna ◽  
Dicaffeoylquinic Acid ◽  
B Virus

The anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid isolated fromLaggera alatawas studied using theD-galactosamine- (D-GalN-) induced hepatocyte damage model, HepG2.2.15 cells, and with HBV transgenic mice.In vitroresults showed that 3,4-O-dicaffeoylquinic acid improved HL-7702 hepatocyte viability and markedly inhibited the production of HBsAg and HBeAg. At a concentration of 100 μg/mL, its inhibitory rates on the expression levels of HBsAg and HBeAg were 89.96% and 81.01%, respectively. The content of hepatitis B virus covalently closed circular DNA (HBV cccDNA) in HepG2.2.15 cells was significantly decreased after the cells were treated with the test compound. In addition, 3,4-O-dicaffeoylquinic acid significantly increased the expression of heme oxygenase-1 (HO-1) in HepG2.2.15 cells.In vivoresults indicated that the test compound at concentrations of 100 μg/mL significantly inhibited HBsAg production and increased HO-1 expression in HBV transgenic mice. In conclusion, this study verifies the anti-hepatitis B activity of 3,4-O-dicaffeoylquinic acid. The upregulation of HO-1 may contribute to the anti-HBV effect of this compound by reducing the stability of the HBV core protein, which blocks the refill of nuclear HBV cccDNA. Furthermore, the hepatoprotective effect of this compound may be mediated through its antioxidative/anti-inflammatory properties and by the induction of HO-1 expression.

Phosphorylation of hepatitis B virus core C-terminally truncated protein (Cp149) by PKC increases capsid assembly and stability

2008 ◽  
Vol 416 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Hang Kang ◽  
Jaehoon Yu ◽  
Guhung Jung
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Virus Titre ◽  
Capsid Assembly ◽  
Human Hepatoma Cells ◽  
Virus Core ◽  
C Terminus ◽  
B Virus

The HBV (hepatitis B virus) core is a phosphoprotein whose assembly, replication, encapsidation and localization are regulated by phosphorylation. It is known that PKC (protein kinase C) regulates pgRNA (pregenomic RNA) encapsidation by phosphorylation of the C-terminus of core, which is a component packaged into capsid. Neither the N-terminal residue phosphorylated by PKC nor the role of the C-terminal phosphorylation have been cleary defined. In the present study we found that HBV Cp149 (core protein C-terminally truncated at amino acid 149) expressed in Escherichia coli was phosphorylated by PKC at Ser106. PKC-mediated phosphorylation increased core affinity, as well as assembly and capsid stability. In vitro phosphorylation with core mutants (S26A, T70A, S106A and T114A) revealed that the Ser106 mutation inhibited phosphorylation of core by PKC. CD analysis also revealed that PKC-mediated phosphorylation stabilized the secondary structure of capsid. When either pCMV/FLAG-Cp149[WT (wild-type)] or pCMV/FLAG-S106A Cp149 was transfected into Huh7 human hepatoma cells, mutant capsid level was decreased by 2.06-fold with the S106A mutant when compared with WT, although the same level of total protein was expressed in both cases. In addition, when pUC1.2x and pUC1.2x/S106A were transfected, mutant virus titre was decreased 2.31-fold compared with WT virus titre. In conclusion, PKC-mediated phosphorylation increased capsid assembly, stability and structural stability.

Transbody against hepatitis B virus core protein inhibits hepatitis B virus replication in vitro

2015 ◽  
Vol 25 (2) ◽  
pp. 363-369 ◽  
Author(s):  
Yawen Wang ◽  
Yiping Li ◽  
Na Li ◽  
Qianqian Zhu ◽  
Lingyun Hui ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Virus Replication ◽  
Core Protein ◽  
Virus Core ◽  
B Virus

The pregenome/C RNA of duck hepatitis B virus is not used for translation of core protein during the early phase of infection in vitro

2015 ◽  
Vol 196 ◽  
pp. 13-19 ◽  
Author(s):  
Qiang Liu ◽  
Juan Huang ◽  
Renyong Jia ◽  
Mingshu Wang ◽  
Dekang Zhu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Early Phase ◽  
Core Protein ◽  
Duck Hepatitis B Virus ◽  
Duck Hepatitis ◽  
B Virus

scholarly journals Synergistic Interactions between Hepatitis B Virus RNase H Antagonists and Other Inhibitors

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Elena Lomonosova ◽  
Adam Zlotnick ◽  
John E. Tavis
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Index Theorem ◽  
Rnase H ◽  
Mass Action ◽  
Significant Activity ◽  
B Virus ◽  
Mass Action Law

ABSTRACT Combination therapies are standard for management of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections; however, no such therapies are established for human hepatitis B virus (HBV). Recently, we identified several promising inhibitors of HBV RNase H (here simply RNase H) activity that have significant activity against viral replication in vitro. Here, we investigated the in vitro antiviral efficacy of combinations of two RNase H inhibitors with the current anti-HBV drug nucleoside analog lamivudine, with HAP12, an experimental core protein allosteric modulator, and with each other. Anti-HBV activities of the compounds were tested in a HepG2-derived cell line by monitoring intracellular core particle DNA levels, and cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. The antiviral efficiencies of the drug combinations were evaluated using the median-effect equation derived from the mass-action law principle and combination index theorem of Chou and Talalay. We found that combinations of two RNase H inhibitors from different chemical classes were synergistic with lamivudine against HBV DNA synthesis. Significant synergism was also observed for the combination of the two RNase H inhibitors. Combinations of RNase H inhibitors with HAP12 had additive antiviral effects. Enhanced cytotoxicity was not observed in the combination experiments. Because of these synergistic and additive effects, the antiviral activity of combinations of RNase H inhibitors with drugs that act by two different mechanisms and with each other can be achieved by administering the compounds in combination at doses below the respective single drug doses.

scholarly journals Antiviral Properties and Mechanism of Action Studies of the Hepatitis B Virus Capsid Assembly Modulator JNJ-56136379

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Jan Martin Berke ◽  
Pascale Dehertogh ◽  
Karen Vergauwen ◽  
Wendy Mostmans ◽  
Koen Vandyck ◽  
...  
Keyword(s):  
Life Cycle ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Protein ◽  
Hbv Dna ◽  
Size Exclusion ◽  
Capsid Assembly ◽  
Phase Ii Trials ◽  
B Virus

ABSTRACT Capsid assembly is a critical step in the hepatitis B virus (HBV) life cycle, mediated by the core protein. Core is a potential target for new antiviral therapies, the capsid assembly modulators (CAMs). JNJ-56136379 (JNJ-6379) is a novel and potent CAM currently in phase II trials. We evaluated the mechanisms of action (MOAs) and antiviral properties of JNJ-6379 in vitro. Size exclusion chromatography and electron microscopy studies demonstrated that JNJ-6379 induced the formation of morphologically intact viral capsids devoid of genomic material (primary MOA). JNJ-6379 accelerated the rate and extent of HBV capsid assembly in vitro. JNJ-6379 specifically and potently inhibited HBV replication; its median 50% effective concentration (EC50) was 54 nM (HepG2.117 cells). In HBV-infected primary human hepatocytes (PHHs), JNJ-6379, when added with the viral inoculum, dose-dependently reduced extracellular HBV DNA levels (median EC50 of 93 nM) and prevented covalently closed circular DNA (cccDNA) formation, leading to a dose-dependent reduction of intracellular HBV RNA levels (median EC50 of 876 nM) and reduced antigen levels (secondary MOA). Adding JNJ-6379 to PHHs 4 or 5 days postinfection reduced extracellular HBV DNA and did not prevent cccDNA formation. Time-of-addition PHH studies revealed that JNJ-6379 most likely interfered with postentry processes. Collectively, these data demonstrate that JNJ-6379 has dual MOAs in the early and late steps of the HBV life cycle, which is different from the MOA of nucleos(t)ide analogues. JNJ-6379 is in development for chronic hepatitis B treatment and may translate into higher HBV functional cure rates.

scholarly journals Identification of Disubstituted Sulfonamide Compounds as Specific Inhibitors of Hepatitis B Virus Covalently Closed Circular DNA Formation

2012 ◽  
Vol 56 (8) ◽  
pp. 4277-4288 ◽  
Author(s):  
Dawei Cai ◽  
Courtney Mills ◽  
Wenquan Yu ◽  
Ran Yan ◽  
Carol E. Aldrich ◽  
...  
Keyword(s):  
Cell Culture ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Polymerase Activity ◽  
Circular Dna ◽  
Drug Candidates ◽  
Covalently Closed Circular Dna ◽  
Hbv Cccdna ◽  
B Virus

ABSTRACTHepatitis B virus (HBV) covalently closed circular DNA (cccDNA) plays a central role in viral infection and persistence and is the basis for viral rebound after the cessation of therapy, as well as the elusiveness of a cure even after extended treatment. Therefore, there is an urgent need for the development of novel therapeutic agents that directly target cccDNA formation and maintenance. By employing an innovative cell-based cccDNA assay in which secreted HBV e antigen is a cccDNA-dependent surrogate, we screened an in-house small-molecule library consisting of 85,000 drug-like compounds. Two structurally related disubstituted sulfonamides (DSS), termed CCC-0975 and CCC-0346, emerged and were confirmed as inhibitors of cccDNA production, with low micromolar 50% effective concentrations (EC50s) in cell culture. Further mechanistic studies demonstrated that DSS compound treatment neither directly inhibited HBV DNA replication in cell culture nor reduced viral polymerase activity in thein vitroendogenous polymerase assay but synchronously reduced the levels of HBV cccDNA and its putative precursor, deproteinized relaxed circular DNA (DP-rcDNA). However, DSS compounds did not promote the intracellular decay of HBV DP-rcDNA and cccDNA, suggesting that the compounds interfere primarily with rcDNA conversion into cccDNA. In addition, we demonstrated that CCC-0975 was able to reduce cccDNA biosynthesis in duck HBV-infected primary duck hepatocytes. This is the first attempt, to our knowledge, to identify small molecules that target cccDNA formation, and DSS compounds thus potentially serve as proof-of-concept drug candidates for development into therapeutics to eliminate cccDNA from chronic HBV infection.

scholarly journals Alkoxyalkyl Esters of 9-(S)-(3-Hydroxy-2-Phosphonomethoxypropyl) Adenine Are Potent and Selective Inhibitors of Hepatitis B Virus (HBV) Replication In Vitro and in HBV Transgenic Mice In Vivo

2009 ◽  
Vol 53 (7) ◽  
pp. 2865-2870 ◽  
Author(s):  
John D. Morrey ◽  
Brent E. Korba ◽  
James R. Beadle ◽  
David L. Wyles ◽  
Karl Y. Hostetler
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Antiviral Activity ◽  
Transgenic Mice ◽  
Adefovir Dipivoxil ◽  
Murine Cytomegalovirus ◽  
Cross Resistance ◽  
B Virus

ABSTRACT Alkoxyalkyl esters of acyclic nucleoside phosphonates have previously been shown to have increased antiviral activity when they are administered orally in animal models of viral diseases, including lethal infections with vaccinia virus, cowpox virus, ectromelia virus, murine cytomegalovirus, and adenovirus. 9-(S)-(3-Hydroxy-2-phosphonomethoxypropyl)adenine [(S)-HPMPA] was previously shown to have activity against hepatitis B virus (HBV) in vitro. To assess the effect of alkoxyalkyl esterification of (S)-HPMPA, we prepared the hexadecyloxypropyl (HDP), 15-methyl-hexadecyloxypropyl (15M-HDP), and octadecyloxyethyl (ODE) esters and compared their activities with the activity of adefovir dipivoxil in vitro and in vivo. Alkoxyalkyl esters of (S)-HPMPA were 6 to 20 times more active than unmodified (S)-HPMPA on the basis of their 50% effective concentrations in 2.2.15 cells. The increased antiviral activity appeared to be due in part to the increased uptake and conversion of HDP-(S)-HPMPA to HPMPA diphosphate observed in HepG2 cells in vitro. HDP-(S)-HPMPA retained full activity against HBV mutants resistant to lamivudine (L180M, M204V), but cross-resistance to a mutant resistant to adefovir (N236T) was detected. HDP-(S)-HPMPA is orally bioavailable and provides excellent liver exposure to the drug. Oral treatment of HBV transgenic mice with HDP-(S)-HPMPA, 15M-HDP-(S)-HPMPA, and ODE-(S)-HPMPA for 14 days reduced liver HBV DNA levels by roughly 1.5 log units, a response equivalent to that of adefovir dipivoxil.

scholarly journals The Hepatitis B Virus X Protein Transactivates Viral Core Gene Expression In Vivo

1999 ◽  
Vol 73 (12) ◽  
pp. 10399-10405 ◽  
Author(s):  
Kurt Reifenberg ◽  
Heike Wilts ◽  
Jürgen Löhler ◽  
Petra Nusser ◽  
Ralph Hanano ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Transgenic Mice ◽  
Gene Product ◽  
Core Protein ◽  
Core Gene ◽  
B Virus ◽  
X Gene

ABSTRACT The function of the X protein in the life cycle of mammalian hepadnaviruses is unclear. Based on tissue culture experiments it has been suggested that this protein represents a transcriptional transactivator which might be essential for the expression of the viral core gene. Here we have examined whether the activity of the human hepatitis B virus (HBV) core gene in vivo depends on X coexpression. To this end we compared core gene expression between four lineages of transgenic mice carrying the HBV core gene in cisarrangement with the X gene (cex lineage) and six lineages containing a modified construct in which the start codon of the X gene had been deleted (ce lineage). Whereas all cex lineages consistently exhibited a high-level hepatic core gene expression, the liver-specific core gene expression pattern of the ce lineages was heterogenous with four lineages virtually not expressing the core gene. This defect was due to a strongly reduced transcription since no core mRNA could be detected by Northern blotting. To test whether core gene expression could be restored by providing an intact X gene in trans, we crossbred mice of two lines which expressed no core mRNA or core protein with transgenic mice expressing the X-gene product under the transcriptional regulation of the liver-specific major-urinary-protein promoter/enhancer (MUP-X mice). The introduction of the MUP-X transgene induced core mRNA expression and core protein biosynthesis in the livers of the double-transgenic mice. This demonstrates that the X-gene product has the capacity to transactivate HBV core gene expression in vivo.

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