scholarly journals Development of a novel anti-hepatitis B virus agent via Sp1

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michiyo Hayakawa ◽  
Hideaki Umeyama ◽  
Mitsuo Iwadate ◽  
Y.-H. Taguchi ◽  
Yoshihiko Yano ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Dependent Manner ◽  
Hbv Replication ◽  
B Virus ◽  
Multiple Regions ◽  
Viral Relapse ◽  
Dose Dependent ◽  
Molecular Compounds ◽  
Alpha Glucosidase ◽  
Effect Gene

AbstractNucleos(t)ide analog (NA) therapy has proven effective in treating chronic hepatitis B. However, NAs frequently result in viral relapse after the cessation of therapy. This is because NAs cannot fully eliminate the viral episomal covalently closed circular DNA (cccDNA) in the nucleus. In this study, we identified small molecular compounds that control host factors related to viral replication using in silico screening with simulated annealing based on bioinformatics for protein-ligand flexible docking. Twelve chemical compound candidates for alpha-glucosidase (AG) inhibitors were identified from a library of chemical compounds and used to treat fresh human hepatocytes infected with HBV. They were then monitored for their anti-viral effects. HBV replication was inhibited by one candidate (1-[3-(4-tert-butylcyclohexyl)oxy-2-hydroxypropyl]-2,2,6,6-tetramethylpiperidin-4-ol) in a dose-dependent manner. This compound significantly reduced ccc DNA production, compared to Entecavir (p < 0.05), and had a lower anti-AG effect. Gene expression analysis and structural analysis of this compound showed that its inhibitive effect on HBV was via interaction with Sp1. The nuclear transcription factor Sp1 acts on multiple regions of HBV to suppress HBV replication. Identifying candidates that control nuclear transcription factors facilitate the development of novel therapies. Drugs with a mechanism different from NA are promising for the elimination of HBV.

scholarly journals Hepatitis B Virus-Encoded MicroRNA Controls Viral Replication

2017 ◽  
Vol 91 (10) ◽  
Author(s):  
Xi Yang ◽  
Hongfeng Li ◽  
Huahui Sun ◽  
Hongxia Fan ◽  
Yaqi Hu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Persistent Infection ◽  
Hepatoma Cell ◽  
Hbv Infection ◽  
Dependent Manner ◽  
Dna Virus ◽  
Hbv Replication ◽  
B Virus ◽  
Self Replication

ABSTRACT MicroRNAs (miRNAs) are a class of small, single-stranded, noncoding, functional RNAs. Hepatitis B virus (HBV) is an enveloped DNA virus with virions and subviral forms of particles that lack a core. It was not known whether HBV encodes miRNAs. Here, we identified an HBV-encoded miRNA (called HBV-miR-3) by deep sequencing and Northern blotting. HBV-miR-3 is located at nucleotides (nt) 373 to 393 of the HBV genome and was generated from 3.5-kb, 2.4-kb, and 2.1-kb HBV in a classic miRNA biogenesis (Drosha-Dicer-dependent) manner. HBV-miR-3 was highly expressed in hepatoma cell lines with an integrated HBV genome and HBV+ hepatoma tumors. In patients with HBV infection, HBV-miR-3 was released into the circulation by exosomes and HBV virions, and HBV-miR-3 expression had a positive correlation with HBV titers in the sera of patients in the acute phase of HBV infection. More interestingly, we found that HBV-miR-3 represses HBsAg, HBeAg, and replication of HBV. HBV-miR-3 targets the unique site of the HBV 3.5-kb transcript to specifically reduce HBc protein expression, levels of pregenomic RNA (pgRNA), and HBV replication intermediate (HBV-RI) generation but does not affect the HBV DNA polymerase level, thus suppressing HBV virion production (replication). This may explain the low levels of HBV virion generation with abundant subviral particles lacking core during HBV replication, which may contribute to the development of persistent infection in patients. Taken together, our findings shed light on novel mechanisms by which HBV-encoded miRNA controls the process of self-replication by regulating HBV transcript during infection. IMPORTANCE Hepatitis B is a liver infection caused by the hepatitis B virus (HBV) that can become a long-term, chronic infection and lead to cirrhosis or liver cancer. HBV is a small DNA virus that belongs to the hepadnavirus family, with virions and subviral forms of particles that lack a core. MicroRNA (miRNA), a small (∼22-nt) noncoding RNA, was recently found to be an important regulator of gene expression. We found that HBV encodes miRNA (HBV-miR-3). More importantly, we revealed that HBV-miR-3 targets its transcripts to attenuate HBV replication. This may contribute to explaining how HBV infection leads to mild damage in liver cells and the subsequent establishment/maintenance of persistent infection. Our findings highlight a mechanism by which HBV-encoded miRNA controls the process of self-replication by regulating the virus itself during infection and might provide new biomarkers for diagnosis and treatment of hepatitis B.

scholarly journals Hepatitis B Virus X Protein Induces Perinuclear Mitochondrial Clustering in Microtubule- and Dynein-Dependent Manners

2006 ◽  
Vol 81 (4) ◽  
pp. 1714-1726 ◽  
Author(s):  
Sujeong Kim ◽  
Hye-Young Kim ◽  
Seungmin Lee ◽  
Sung Woo Kim ◽  
Seonghyang Sohn ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nuclear Periphery ◽  
Mitogen Activated Protein Kinase ◽  
Transport Systems ◽  
Dependent Manner ◽  
Atpase Inhibitor ◽  
X Protein ◽  
Hbv Replication ◽  
B Virus

ABSTRACT The hepatitis B virus (HBV) X protein (HBx) is thought to play a key role in HBV replication and the development of liver cancer. It became apparent that HBx induces mitochondrial clustering at the nuclear periphery, but the molecular basis for mitochondrial clustering is not understood. Since mitochondria move along the cytoskeleton as a cargo of motor proteins, we hypothesized that mitochondrial clustering induced by HBx occurs by an altered intracellular motility. Here, we demonstrated that the treatment of HBx-expressing cells with a microtubule-disrupting drug (nocodazole) abrogated mitochondrial clustering, while the removal of nocodazole restored clustering within 30 to 60 min, indicating that mitochondrial transport is occurring in a microtubule-dependent manner. The addition of a cytochalasin D-disrupting actin filament, however, did not measurably affect mitochondrial clustering. Mitochondrial clustering was further studied by observations of HBV-related hepatoma cells and HBV-replicating cells. Importantly, the abrogation of the dynein activity in HBx-expressing cells by microinjection of a neutralizing anti-dynein intermediate-chain antibody, dynamitin overexpression, or the addition of a dynein ATPase inhibitor significantly suppressed the mitochondrial clustering. In addition, HBx induced the activation of the p38 mitogen-activated protein kinase (MAPK) and inhibition of the p38 kinase activity by SB203580-attenuated HBx-induced mitochondrial clustering. Taken together, HBx activation of the p38 MAPK contributed to the increase in the microtubule-dependent dynein activity. The data suggest that HBx plays a novel regulatory role in subcellular transport systems, perhaps facilitating the process of maturation and/or assembly of progeny particles during HBV replication. Furthermore, mitochondrion aggregation induced by HBx may represent a cellular process that underlies disease progression during chronic viral infection.

Dual effects of interleukin-18: inhibiting hepatitis B virus replication in HepG2.2.15 cells and promoting hepatoma cells metastasis

2011 ◽  
Vol 301 (3) ◽  
pp. G565-G573 ◽  
Author(s):  
Yijuan Zhang ◽  
Yunbo Li ◽  
Yifan Ma ◽  
Shuhui Liu ◽  
Yinglong She ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Hepatoma Cells ◽  
Human Hepatocytes ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Interleukin 18 ◽  
Hbv Replication ◽  
B Virus ◽  
And Migration

Interleukin-18 (IL-18) has been reported to inhibit hepatitis B virus (HBV) replication in the liver of HBV transgenic mice; however, the molecular mechanism of its antiviral effect has not been fully understood. In the present study, it was shown that IL-18 and its receptors (IL-18R) were constitutively expressed in hepatoma cell lines HepG2 and HepG2.2.15 as well as normal liver cell line HL-7702. We demonstrated that IL-18 directly inhibited HBV replication in HepG2.2.15 cells via downregulating the activities of HBV core and X gene promoters. The suppressed HBV replication by IL-18 could be rescued by the administration of BAY11-7082, an inhibitor of transcription factor NF-κB. On the other hand, it was of interest that IL-18 promoted HepG2 cell metastasis and migration dose dependently in both wound-healing assays and Transwell assays. The underlying mechanism could be partially attributable to the increased activities of extracellular matrix metalloproteinase (MMP)-9, MMP-3, and MMP-2 by IL-18, which upregulated the mRNA levels of MMP-3 and MMP-9 in a NF-κB-dependent manner. Furthermore, it was confirmed that expression of IL-18/IL-18R and most MMPs were remarkably upregulated in hepatocellular carcinoma (HCC) liver cancer tissue specimens, suggesting that IL-18/IL-18R-triggered signaling pathway was closely related to HCC metastasis in vivo. Therefore, we revealed the dual effects of IL-18 in human hepatocytes: it not only inhibited HBV replication but also promoted hepatoma cells metastasis and migration. NF-κB played a critical role in both effects. Our work contributed to a deeper understanding of the biological function of IL-18 in human hepatocytes.

scholarly journals Toll-Like Receptor Signaling Inhibits Hepatitis B Virus Replication In Vivo

2005 ◽  
Vol 79 (11) ◽  
pp. 7269-7272 ◽  
Author(s):  
Masanori Isogawa ◽  
Michael D. Robek ◽  
Yoshihiro Furuichi ◽  
Francis V. Chisari
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Therapeutic Strategy ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Chronic Hbv Infection ◽  
Hbv Replication ◽  
B Virus ◽  
Chronic Hbv

ABSTRACT Toll-like receptors (TLR) play a key role in innate immunity. To examine the ability of diverse TLRs to modulate hepatitis B virus (HBV) replication, HBV transgenic mice received a single intravenous injection of ligands specific for TLR2, TLR3, TLR4, TLR5, TLR7, and TLR9. All of the ligands except for TLR2 inhibited HBV replication in the liver noncytopathically within 24 h in a α/β interferon-dependent manner. The ability of these TLR ligands to induce antiviral cytokines at the site of HBV replication suggests that TLR activation could represent a powerful and novel therapeutic strategy for the treatment of chronic HBV infection.

RNA Helicase DDX17 inhibits Hepatitis B Virus Replication by Blocking Viral Pregenomic RNA Encapsidation

2021 ◽  
Author(s):  
Richeng Mao ◽  
Minhui Dong ◽  
Zhongliang Shen ◽  
Hu Zhang ◽  
Yuanjie Liu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Rna Degradation ◽  
Viral Rna ◽  
Health Concern ◽  
Dependent Manner ◽  
Stem Loop ◽  
Hbv Replication ◽  
Dead Box ◽  
B Virus

DDX17 is a member of the DEAD-Box helicase family proteins involved in cellular RNA folding, splicing, and translation. It has been reported that DDX17 serves as a co-factor of host zinc finger antiviral protein (ZAP)-mediated retroviral RNA degradation and exerts direct antiviral function against Raft Valley Fever Virus though binding to specific stem-loop structures of viral RNA. Intriguingly, we have previously shown that ZAP inhibits Hepatitis B virus (HBV) replication through promoting viral RNA decay, and the ZAP-responsive element (ZRE) of HBV pregenomic RNA (pgRNA) contains a stem-loop structure, specifically epsilon, which serves as the packaging signal for pgRNA encapsidation. In this study, we demonstrated that the endogenous DDX17 is constitutively expressed in human hepatocyte-derived cells but dispensable for ZAP-mediated HBV RNA degradation. However, DDX17 was found to inhibit HBV replication primarily by reducing the level of cytoplasmic encapsidated pgRNA in a helicase-dependent manner. Immunofluorescence assay revealed that DDX17 could gain access to cytoplasm from nucleus in the presence of HBV RNA. In addition, RNA immunoprecipitation and electrophoretic mobility shift assays demonstrated that the enzymatically active DDX17 competes with HBV polymerase to bind to pgRNA at the 5’ epsilon motif. In summary, our study suggests that DDX17 serves as an intrinsic host restriction factor against HBV through interfering with pgRNA encapsidation. IMPORTANCE Hepatitis B virus (HBV) chronic infection, a long-studied but yet incurable disease, remains a major public health concern worldwide. Given that HBV replication cycle highly depends on host factors, deepening our understanding of the host-virus interaction is thus of great significance in the journey of finding a cure. In eukaryotic cells, RNA helicases of DEAD-box family are highly conserved enzymes involved in diverse processes of cellular RNA metabolism. Emerging data have shown that DDX17, a typical member of DEAD box family, functions as an antiviral factor through interacting with viral RNA. In this study, we, for the first time, demonstrate that DDX17 inhibits HBV through blocking the formation of viral replication complex, which not only broadens the antiviral spectrum of DDX17, but also provides new insight into the molecular mechanism of DDX17-mediated virus-host interaction.

scholarly journals Interferons Accelerate Decay of Replication-Competent Nucleocapsids of Hepatitis B Virus

2010 ◽  
Vol 84 (18) ◽  
pp. 9332-9340 ◽  
Author(s):  
Chunxiao Xu ◽  
Haitao Guo ◽  
Xiao-Ben Pan ◽  
Richeng Mao ◽  
Wenquan Yu ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Dependent Manner ◽  
Hbv Replication ◽  
B Virus ◽  
Cellular Antiviral Response ◽  
Ifn Γ ◽  
Antiviral Mechanism ◽  
Murine Hepatocyte

ABSTRACT Alpha interferon (IFN-α) is an approved medication for chronic hepatitis B. Gamma interferon (IFN-γ) is a key mediator of host antiviral immunity against hepatitis B virus (HBV) infection in vivo. However, the molecular mechanism by which these antiviral cytokines suppress HBV replication remains elusive. Using an immortalized murine hepatocyte (AML12)-derived cell line supporting tetracycline-inducible HBV replication, we show in this report that both IFN-α and IFN-γ efficiently reduce the amount of intracellular HBV nucleocapsids. Furthermore, we provide evidence suggesting that the IFN-induced cellular antiviral response is able to distinguish and selectively accelerate the decay of HBV replication-competent nucleocapsids but not empty capsids in a proteasome-dependent manner. Our findings thus reveal a novel antiviral mechanism of IFNs and provide a basis for a better understanding of HBV pathobiology.

scholarly journals Havachoobe (Onosma dichroanthum Boiss) Root Extract Decreases the Hepatitis B Virus Surface Antigen Secretion in the PLC/PRF/5 Cell Line

Intervirology ◽  
2020 ◽  
pp. 1-5
Author(s):  
Alireza Mohebbi ◽  
Fahimeh Azadi ◽  
Mohammad Mostakhdem Hashemi ◽  
Fatemeh Sana Askari ◽  
Nazanin Razzaghi
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Cell Line ◽  
Real Time ◽  
Real Time Pcr ◽  
Time Dependent ◽  
Root Extract ◽  
Dependent Manner ◽  
B Virus ◽  
Dose Dependent

<b><i>Background:</i></b> Many efforts are currently focused on functional treatment of the hepatitis B virus (HBV). This can be done by suppressing the secretion of HBV surface antigen (HBsAg). Scientific communities are very interested in natural products in that respect. <b><i>Objective:</i></b> Use of root extract of Havachoobe (<i>Onosma dichroanthum BoissI</i>), a Northern Iranian native medical herb, for assessment of its anti-HBsAg secretion activity. <b><i>Methods:</i></b> Havachoobe had been bought at a nearby apothecary store. Plant root extract was obtained using a hydroalcoholic process. Cytotoxic activity of the extract was examined on PLC/PRF/5 cells using MTT assay. ELISA has been used to measure HBsAg in the treated cell line supernatants. In addition, real-time PCR analysis was performed to evaluate the expression of HBsAg before and after treatment of Onosma in vitro. <b><i>Results:</i></b> The results showed very low root extract cytotoxicity at concentrations under 8 μg/mL. Tissue culture infectious dose 50 was obtained at 63.78 μg/mL. In a dose-dependent and time-dependent manner, a significantly reduced HBsAg secretion was observed at a concentration of 8 ppm at 12 h post-treatment. The real-time PCR result showed relative decreased HBsAg expression at all doses at 12 h post-treatment time. <b><i>Discussion:</i></b> In this study, we first reported anti-HBsAg activity on an Iranian herbal medicine. Havachoobe root extract was shown to be able to inhibit HBsAg in a dose-dependent and time-dependent manner. We find the extract exerts its inhibitory effect of HBsAg by targeting transcription of HBsAg.

Anti-Hepatitis B Virus Effects of Dehydrocheilanthifoline fromCorydalis saxicola

2013 ◽  
Vol 41 (01) ◽  
pp. 119-130 ◽  
Author(s):  
Fan-Li Zeng ◽  
Yang-Fei Xiang ◽  
Zhen-Ran Liang ◽  
Xiao Wang ◽  
Dan-e Huang ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Therapeutic Index ◽  
Extracellular Dna ◽  
Dependent Manner ◽  
Promising Candidate ◽  
B Virus ◽  
First Time ◽  
Dose Dependent

In this report, the anti-hepatitis B virus (HBV) activity of dehydrocheilanthifoline (DHCH), a quaternary ammonium alkaloid isolated from the traditional Chinese medicine Corydalis saxicola Bunting (Papaveraceae), was determined in vitro. Following six days of treatment, DHCH efficiently suppressed the secretions of HBsAg and HBeAg in HepG2.2.15 cell cultures, with a half-maximal inhibitory concentration (IC50) of 15.84 and 17.12 μM, and with a therapeutic index (TI) of 7.32 and 6.77, respectively. Further studies revealed that DHCH reduced the levels of extracellular DNA, intracellular DNA and covalently closed circular DNA (cccDNA) of HBV in a dose-dependent and time-dependent manner, with IC50values of 15.08, 7.62 and 8.25 μM, respectively after six days of treatment. In contrast, the level of viral pre-genomic RNA (pgRNA) increased 6.13-fold after treatment with DHCH. Together, it was demonstrated for the first time that DHCH could significantly inhibit the replication of HBV, which warrants further studies on the antiviral mechanisms of DHCH, and suggests that it may be a promising candidate in the therapy of HBV infection.

scholarly journals Hepatitis B Virus Replication Is Associated with an HBx-Dependent Mitochondrion-Regulated Increase in Cytosolic Calcium Levels

2007 ◽  
Vol 81 (21) ◽  
pp. 12061-12065 ◽  
Author(s):  
Stephanie L. McClain ◽  
Amy J. Clippinger ◽  
Rebecca Lizzano ◽  
Michael J. Bouchard
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Molecular Mechanisms ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Cytosolic Calcium ◽  
Hbv Replication ◽  
B Virus

ABSTRACT The nonstructural hepatitis B virus (HBV) protein HBx has an important role in HBV replication and in HBV-associated liver disease. Many activities have been linked to HBx expression; however, the molecular mechanisms underlying many of these activities are unknown. One proposed HBx function is the regulation of cytosolic calcium. We analyzed calcium levels in HepG2 cells that expressed HBx or replicating HBV, and we demonstrated that HBx, expressed in the absence of other HBV proteins or in the context of HBV replication, elevates cytosolic calcium. We linked this elevation of cytosolic calcium to the association of HBx with the mitochondrial permeability transition pore.

Sign in / Sign up

Export Citation Format

Share Document