Inhibit Hepatitis B Virus Replication Research Articles

A novel hepatitis B virus capsid assembly modulator QL-007 inhibits HBV replication and infection through altering capsid assembly

The core protein allosteric modulators (CpAMs) have shown great potential as highly effective antiviral drugs against hepatitis B virus (HBV) in preclinical studies and clinical trials. In this study, we evaluated a small molecule compound called QL-007, which could potentially influence capsid assembly, using HBV replicated and susceptible cell models as well as mice infected with rAAV-HBV. QL-007 significantly inhibited HBV replication in a dose-dependent manner both in vitro and in vivo, resulting in significant decreases in HBV DNA, 3.5 kb HBV RNA and HBeAg. Furthermore, QL-007 not only induced the formation of misshaped Cp149 capsids but also possessed the capability to disassemble HBV capsids. It is noteworthy that QL-007 effectively reduced cccDNA biosynthesis in de novo infections. Mechanistically, QL-007 blocked the encapsidation of pgRNA and induced aberrant polymers assembly at concentrations ≥100 nM, while having no impact on the stability of core proteins. In conclusion, our findings underscore the potential of QL-007 as an effective agent against HBV replication and introduce it as a novel CpAM for the antiviral treatment of chronic hepatitis B.

SCD1 inhibits HBV replication by regulating autophagy under high lipid conditions.

Chronic hepatitis B virus (HBV) infection remains a significant public health concern worldwide. Several metabolic processes regulate HBV DNA replication, including autophagy and lipid metabolism. In this study, we clarified the effect of lipids on HBV replication and elucidated possible mechanisms. We discovered that lipid metabolic gene expression levels were negatively correlated with the HBV DNA in plasma. Our data showed that fatty acid stimulation significantly reduced HBV DNA, hepatitis B surface antigen (HBsAg), and hepatitis B e antigen (HBeAg) levels in HepG2.2.15 cells, which are human hepatoma cell cultures transfected with HBV DNA. The Stearoyl coenzyme A desaturase 1 (SCD1)-autophagy pathway has also been implicated in inhibiting HBV replication by fatty acids stimulation. SCD1 knockdown deregulates the inhibitory effect of fatty acids on HBV by enhancing autophagy. When 3 methyladenine (3MA) was added, the inhibitory effects of specific autophagy inhibitors eliminated the positive effects of SCD1 knockdown on HBV replication. Our results indicate that SCD1 participates in the regulation of inhibition of HBV replication by fatty acids stimulation through regulating autophagy.

Hydrogen Peroxide Inhibits Hepatitis B Virus Replication by Downregulating HBx Levels via Siah-1-Mediated Proteasomal Degradation in Human Hepatoma Cells.

The hepatitis B virus (HBV) is constantly exposed to significant oxidative stress characterized by elevated levels of reactive oxygen species (ROS), such as H2O2, during infection in hepatocytes of patients. In this study, we demonstrated that H2O2 inhibits HBV replication in a p53-dependent fashion in human hepatoma cell lines expressing sodium taurocholate cotransporting polypeptide. Interestingly, H2O2 failed to inhibit the replication of an HBV X protein (HBx)-null HBV mutant, but this defect was successfully complemented by ectopic expression of HBx. Additionally, H2O2 upregulated p53 levels, leading to increased expression of seven in absentia homolog 1 (Siah-1) levels. Siah-1, an E3 ligase, induced the ubiquitination-dependent proteasomal degradation of HBx. The inhibitory effect of H2O2 was nearly abolished not only by treatment with a representative antioxidant, N-acetyl-L-cysteine but also by knockdown of either p53 or Siah-1 using specific short hairpin RNA, confirming the role of p53 and Siah-1 in the inhibition of HBV replication by H2O2. The present study provides insights into the mechanism that regulates HBV replication under conditions of oxidative stress in patients.

Chronic Hepatitis B Infection: New Approaches towards Cure.

Chronic hepatitis B virus (HBV) infection leads to the development of cirrhosis and hepatocellular carcinoma. Lifelong treatment with nucleotides/nucleoside antiviral agents is effective at suppressing HBV replication, however, adherence to daily therapy can be challenging. This review discusses recent advances in the development of long-acting formulations for HBV treatment and prevention, which could potentially improve adherence. Promising new compounds that target distinct steps of the virus life cycle are summarized. In addition to treatments that suppress viral replication, curative strategies are focused on the elimination of covalently closed circular DNA and the inactivation of the integrated viral DNA from infected hepatocytes. We highlight promising long-acting antivirals and genome editing strategies for the elimination or deactivation of persistent viral DNA products in development.

Inhibition of Hepatitis B Virus (HBV) replication and antigen expression by Brucea javanica (L.) Merr. oil emulsion.

The seeds of Brucea javanica (L.) Merr. (BJ) have been traditionally used to treat various types of cancers for many years in China. In this study, we systematically investigated a BJ oil emulsion (BJOE) produced from BJ seeds with the purpose of evaluating its antiviral effect against hepatitis B virus (HBV). HepG2.215 (a wild-type HBV cell line), HepG2, and Huh7, transfected with wildtype (WT) or lamivudine-resistance mutant (LMV-MT) HBV replicon plasmids, were treated with different doses of BJOE and then used for pharmacodynamic evaluation. Cell viability was determined using CCK8 assay. The levels of HBsAg/HBeAg in cell cultured supernatant, HBcAg in cell lysis solution, and HBV DNA in both were evaluated. BJOE at ≤5 mg/ml was nontoxic to carcinoma cell lines, but could significantly inhibit WT/LMV-MT HBV replication and HBs/e/c antigen expression in a dose-dependent manner by upregulating interleukin-6 (IL-6), demonstrating that it possesses moderate anti-HBV activity. As one of the major components of BJOE, bruceine B was found to play a dominant role in IL-6 induction and HBV inhibition. Our results demonstrated that BJOE suppressed HBV replication by stimulating IL-6, indicating that it has promising clinical therapeutic potential for both WT and LMV-MT HBV.

Tannic Acid Suppresses HBV Replication via the Regulation of NF-κB, MAPKs, and Autophagy in HepG2.2.15 Cells.

Hepatitis B virus (HBV) infection is a serious global health problem that threatens the health of human. Tannic acid (TA), a natural polyphenol in foods, fruits, and plants, exhibits a variety of bioactive functions. In our research, we decide to explore the pharmacological mechanism of TA against HBV replication. Our results showed that TA effectively reduced the content of HBV DNA and viral antigens (HBsAg and HBeAg) in HepG2.2.15 cells. Meanwhile, TA significantly decreased the mRNA expression of HBV RNA, which include total HBV RNA, HBV pregenomic RNA, and HBV precore mRNA. Besides, TA evidently downregulated the activity of HBV promoters in HepG2.2.15 cells. Furthermore, we found that TA upregulated the expression of IL-8, TNF-α, IFN-α, and IFN-α-mediated antiviral effectors in HepG2.2.15 cells. On the contrary, TA downregulated the expression of IL-10 and hepatic nuclear factor 4 (HNF4α). In addition, TA activated the NF-κB and MAPK pathways that contributed to the inhibition of HBV replication. Finally, TA treatment led to the occurrence of autophagy, which accelerated the elimination of HBV components in HepG2.2.15 cells. Taken together, our results elucidated the suppressive effect of TA on HBV replication and provided inspiration for its clinical application in HBV treatment.

Efficacy and safety of the siRNA JNJ-73763989 and the capsid assembly modulator JNJ-56136379 (bersacapavir) with nucleos(t)ide analogues for the treatment of chronic hepatitis B virus infection (REEF-1): a multicentre, double-blind, active-controlled, randomised, phase 2b trial

JNJ-73763989 (JNJ-3989), a small interfering RNA, targets all hepatitis B virus (HBV) RNAs, reducing all HBV proteins. JNJ-56136379 (JNJ-6379; also known as bersacapavir), a capsid assembly modulator, inhibits HBV replication. We aimed to evaluate the efficacy (ie, antiviral activity) and safety of these therapeutics in combination with nucleos(t)ide analogues in patients with chronic hepatitis B. The REEF-1 multicentre, double-blind, active-controlled, randomised, phase 2b study was done at 108 hospitals or outpatient centres across 19 countries in Asia, Europe, and North and South America. We included patients aged 18-65 years with chronic hepatitis B (defined as HBsAg positivity at screening and at least 6 months before screening or alternative markers of chronicity [eg, HBV DNA]), including those not currently treated, virologically suppressed, HBeAg positive, and HBeAg negative. Patients were randomly assigned (1:1:2:2:2:2) via permuted block randomisation according to a computer-generated schedule to receive oral nucleos(t)ide analogues once per day plus placebo (control group); oral JNJ-6379 250 mg daily plus nucleos(t)ide analogues (JNJ-6379 dual group); nucleos(t)ide analogues plus subcutaneously injected JNJ-3989 at doses of 40 mg (JNJ-3989 dual 40 mg group), 100 mg (JNJ-3989 dual 100 mg group), or 200 mg (JNJ-3989 dual 200 mg group) every 4 weeks; or JNJ-6379 250 mg plus JNJ-3989 100 mg every 4 weeks plus nucleos(t)ide analogues (triple group) for 48 weeks followed by a follow-up phase. An interactive web response system provided concealed treatment allocation, and investigators remained masked to the intervention groups until the primary analysis at week 48. The primary endpoint was the proportion of patients meeting predefined nucleos(t)ide analogue-stopping criteria (alanine aminotransferase <3 × upper limit of normal, HBV DNA below the lower limit of quantitation, HBeAg negative, and HBsAg <10 IU/mL) at week 48. All patients who received at least one dose of study drug were included in the analysis population used for primary efficacy assessment, excluding those who withdrew because of COVID-19-related reasons, withdrew before week 44, or had no efficacy data (ie, the modified intention-to-treat population). Safety was assessed in all participants who received at least one dose of study drugs. This trial is registered with ClinicalTrials.gov, NCT03982186. The study has been completed. Between Aug 1, 2019, and April 26, 2022, 470 patients (310 [66%] male and 244 [52%] White) were randomly assigned: 45 to the control group, 48 to the JNJ-6379 dual group, 93 to the JNJ-3989 dual 40 mg group, 93 to the JNJ-3989 dual 100 mg group, 96 to the JNJ-3989 dual 200 mg group, and 95 to the triple group. At week 48, five (5%; 90% CI 2-11) of 91 patients in the JNJ-3989 dual 40 mg group, 15 (16%; 10-24) of 92 in the JNJ-3989 dual 100 mg group, 18 (19%; 13-27) of 94 in the JNJ-3989 dual 200 mg group, eight (9%; 4-15) of 94 in the triple group, and one (2%; 0-10) of 45 in the control group met nucleos(t)ide analogue stopping criteria. No patients in the JNJ-6379 dual group met stopping criteria. 38 (81%) patients who met nucleos(t)ide analogue-stopping criteria at week 48 were virologically suppressed and HBeAg negative at baseline. Ten (2%) of 470 patients had serious adverse events during the treatment phase, and two patients (one each from the JNJ-3989 dual 200 mg group [exercise-related rhabdomyolysis] and the triple group [increase in ALT or AST]) had serious adverse events related to study treatment. During follow-up, 12 (3%) of 460 patients had a serious adverse event; one (<1%), a gastric ulcer, was considered to be related to nucleos(t)ide analogues and occurred in a patient from the JNJ-3989 dual 200 mg group. 29 (6%) of 460 patients in the treatment phase and in ten (2%) of 460 patients in the follow-up phase had grade 3 or 4 adverse events. Five (1%) of 470 patients discontinued treatment due to adverse events, and there were no deaths. Although treatment with JNJ-3989 led to a dose-dependent response for meeting nucleos(t)ide analogue-stopping criteria, it rarely led to HBsAg seroclearance. However, most patients treated with JNJ-3989 had clinically meaningful reductions in HBsAg that might contribute to a liver environment conducive to better immune control and, in turn, might improve the response to immune-modulating therapies. Janssen Research and Development.

Deficiency of SCAP inhibits HBV pathogenesis via activation of the interferon signaling pathway

Hepatitis B virus (HBV) infects the liver and is a major risk factor for liver cirrhosis and hepatocellular carcinoma. Approaches for an effective cure are thwarted by limited knowledge of virus-host interactions. Herein, we identified SCAP as a novel host factor that regulates HBV gene expression. SCAP, sterol regulatory element-binding protein (SREBP) cleavage-activating protein, is an integral membrane protein located in the endoplasmic reticulum. The protein plays a central role in controlling lipid synthesis and uptake by cells. We found that gene silencing of SCAP significantly inhibited HBV replication; furthermore, knockdown of SREBP2 but not SREBP1, the downstream effectors of SCAP, reduced HBs antigen production from HBV infected primary hepatocytes. We also demonstrated that knockdown of SCAP resulted in activation of interferons (IFNs) and IFN stimulated genes (ISGs). Conversely, ectopic expression of SREBP2 in SCAP-deficient cells restored expression of IFNs and ISGs. Importantly, expression of SREBP2 restored HBV production in SCAP knockdown cells, suggesting that SCAP participates in HBV replication through an effect on IFN production via its downstream effector SREBP2. This observation was further confirmed by blocking IFN signaling by an anti-IFN antibody, which restored HBV infection in SCAP-deficient cells. This led to the conclusion that SCAP regulates the IFN pathway through SREBP, thereby affecting the HBV lifecycle. This is the first study to reveal the involvement of SCAP in regulation of HBV infection. These results may facilitate development of new antiviral strategies against HBV.

RNA-binding motif protein 24 inhibits HBV replication in vivo.

Despite the extensive use of effective vaccines and antiviral drugs, chronic hepatitis B virus (HBV) infection continues to pose a serious threat to global public health. Therapies with novel mechanisms of action against HBV are being explored for achieving a functional cure. In this study, five murine models of HBV replication were used to investigate the inhibitory effect of RNA binding motif protein 24 (RBM24) on HBV replication. The findings revealed that RBM24 serves as a host restriction factor and suppresses HBV replication in vivo. The transient overexpression of RBM24 in hydrodynamics-based mouse models of HBV replication driven by the CMV or HBV promoters suppressed HBV replication. Additionally, the ectopic expression of RBM24 decreased viral accumulation and the levels of HBV covalently closed circular DNA (cccDNA) in an rcccDNA mouse model. The liver-directed transduction of adeno-associated viruses(AAV)-RBM24 mediated the stable hepatic expression of RBM24 in pAAV-HBV1.2 and HBV/tg mouse models, and markedly reduced the levels of HBV cccDNA and other viral indicators. Altogether, these findings revealed that RBM24 inhibits the replication of HBV in vivo, and RBM24 may be a potential therapeutic target for combating HBV infections.

Synthetic gRNA/Cas9 ribonucleoprotein targeting HBV DNA inhibits viral replication.

The presence of hepatitis B virus (HBV) covalently closed circular (ccc) DNA (cccDNA), which serves as a template for viral replication and integration of HBV DNA into the host cell genome, sustains liver pathogenesis and constitutes an intractable barrier to the eradication of chronic HBV infection. The current antiviral therapy for HBV infection, using nucleos(t)ide analogues (NAs), can suppress HBV replication but cannot eliminate integrated HBV DNA and episomal cccDNA. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 is a powerful genetic tool that can edit integrated HBV DNA and minichromosomal cccDNA for gene therapy, but its expression and delivery require a viral vector, which poses safety concerns for therapeutic applications in humans. In the present study, we used synthetic guide RNA (gRNA)/Cas9-ribonucleoprotein (RNP) as a nonviral formulation to develop a novel CRISPR/Cas9-mediated gene therapy for eradicating HBV infection. We designed a series of gRNAs targeting multiple specific HBV genes and tested their antiviral efficacy and cytotoxicity in different HBV cellular models. Transfection of stably HBV-infected human hepatoma cell line HepG2.2.15 with HBV-specific gRNA/Cas9 RNPs resulted in a substantial reduction in HBV transcripts. Specifically, gRNA5 and/or gRNA9 RNPs significantly reduced HBV cccDNA, total HBV DNA, pregenomic RNA, and HBV antigen (HBsAg, HBeAg) levels. T7 endonuclease 1 (T7E1) cleavage assay and DNA sequencing confirmed specific HBV gene cleavage and mutations at or around the gRNA target sites. Notably, this gene-editing system did not alter cellular viability or proliferation in the treated cells. Because of their rapid DNA cleavage capability, low off-target effects, low risk of insertional mutagenesis, and readiness for use in clinical application, these results suggest that synthetic gRNA/Cas9 RNP-based gene-editing can be utilized as a promising therapeutic drug for eradicating chronic HBV infection.

Hepatitis B virus associated cirrhosis: overview of prognostic and management

Hepatitis B virus (HBV) infection is a global public health problem ; two billion people worldwide have evidence of past or present infection with HBV, and 296 million individuals are chronic carriers (i.e., positive for hepatitis B surface antigen [HBsAg]), of whom approximately 887,000 dies annually from HBV-related liver disease: chronic hepatitis B-associated cirrhosis and hepatocellular carcinoma. There are described some risk factors to the development of cirrhosis to HBV-infected persons: alcohol consumption, HBeAg status, metabolic syndrome, HBV genotypes and variants, and the level of HBV replication. The observation of a strong association between the development and decompensation of cirrhosis as well as between the development of HCC and the level of HBV replication suggests that suppression of HBV replication by long-term antiviral treatment may decrease the risk of complications in patients with HBV-related cirrhosis. The indication for antiviral treatment is given if any HBV DNA levels are detectable in the serum of HBV-infected patients with cirrhosis. Into the new era of antiviral treatment with nucleos(t)ide analogs we can prevent the development of cirrhosis in patients with chronic HBV infection and hepatic decompensation in many patients with HBV-related cirrhosis.

All-trans Retinoic Acid Inhibits Hepatitis B Virus Replication by Downregulating HBx Levels via Siah-1-Mediated Proteasomal Degradation.

All-trans retinoic acid (ATRA), the most biologically active metabolite of vitamin A, is known to abolish the potential of HBx to downregulate the levels of p14, p16, and p21 and to stimulate cell growth during hepatitis B virus (HBV) infection, contributing to its chemopreventive and therapeutic effects against HBV-associated hepatocellular carcinoma. Here, we demonstrated that ATRA antagonizes HBx to inhibit HBV replication. For this effect, ATRA individually or in combination with HBx upregulated p53 levels, resulting in upregulation of seven in absentia homolog 1 (Siah-1) levels. Siah-1, an E3 ligase, induces ubiquitination and proteasomal degradation of HBx in the presence of ATRA. The ability of ATRA to induce Siah-1-mediated HBx degradation and the subsequent inhibition of HBV replication was proven in an in vitro HBV replication model. The effects of ATRA became invalid when either p53 or Siah-1 was knocked down by a specific shRNA, providing direct evidence for the role of p53 and Siah-1 in the negative regulation of HBV replication by ATRA.

Strongylocentrotus nudus egg polysaccharide (SEP) suppresses HBV replication via activation of TLR4-induced immune pathway

Chronic hepatitis B virus (HBV) infection is a worldwide public health problem that causes significant liver-related morbidity and mortality. In our previous study, Strongylocentrotus nudus eggs polysaccharide (SEP), extracted from sea urchins, had immunomodulatory and antitumor effects. Whether SEP has anti-HBV activity is still obscure. This study demonstrated that SEP decreased the secretion of hepatitis B surface antigen (HBsAg) and e antigen (HBeAg), as well as the replication and transcription of HBV both in vitro and in vivo. Immunofluorescence and immunohistochemistry results showed that the level of HBV core antigen (HBcAg) was clearly reduced by SEP treatment. Mechanistically, RT-qPCR, western blot, and confocal microscopy analysis showed that SEP significantly increased the expression of toll-like receptor 4 (TLR4) and co-localization with TLR4. The downstream molecules of TLR4, including NF-κb and IRF3, were activated and the expression of IFN-β, TNF-α, IL-6, OAS, and MxA were also increased, which could suppress HBV replication. Moreover, SEP inhibited other genotypes of HBV and hepatitis C virus (HCV) replication in vitro. In summary, SEP could be investigated as a potential anti-HBV drug capable of modulating the innate immune.

Exploring the mechanism of JiGuCao capsule formula on treating hepatitis B virus infection via network pharmacology analysis and in vivo/vitro experiment verification.

The JiGuCao capsule formula (JCF) has demonstrated promising curative effects in treating chronic hepatitis B (CHB) in clinical trials. Here, we aimed to investigate JCF's function and mechanism in diseases related to the hepatitis B virus (HBV). We used mass spectrometry (MS) to identify the active metabolites of JCF and established the HBV replication mouse model by hydrodynamically injecting HBV replication plasmids into the mice's tail vein. Liposomes were used to transfect the plasmids into the cells. The CCK-8 kit identified cell viability. We detected the levels of HBV s antigen (HBsAg) and HBV e antigen (HBeAg) by the quantitative determination kits. qRT-PCR and Western blot were used to detect the genes' expression. The key pathways and key genes related to JCF on CHB treatment were obtained by network pharmacological analysis. Our results showed that JCF accelerated the elimination of HBsAg in mice. JCF and its medicated serum inhibited HBV replication and proliferation of HBV-replicating hepatoma cells in vitro. And the key targets of JCF in treating CHB were CASP3, CXCL8, EGFR, HSPA8, IL6, MDM2, MMP9, NR3C1, PTGS2, and VEGFA. Furthermore, these key targets were related to pathways in cancer, hepatitis B, microRNAs in cancer, PI3K-Akt signaling, and proteoglycans in cancer pathways. Finally, Cholic Acid, Deoxycholic Acid, and 3', 4', 7-Trihydroxyflavone were the main active metabolites of JCF that we obtained. JCF employed its active metabolites to perform an anti-HBV effect and prevent the development of HBV-related diseases.

Inhibition of HBV replication by EVA1A via enhancing cellular degradation of HBV components and its potential therapeutic application

Hepatitis B virus (HBV) DNA is much higher during HBeAg-positive chronic HBV infection (EP-CBI) than during HBeAg-negative chronic HBV infection (EN-CBI), although the necroinflammation in liver is minimal and the adaptive immune response is similar in both phases. We previously reported that mRNA levels of EVA1A were higher in EN-CBI patients. In this study, we aimed to investigate whether EVA1A inhibits HBV gene expression and examine the underlying mechanisms. The available cell models for HBV replication and model HBV mice were used to investigate how EVA1A regulates HBV replication and the antiviral activity based on gene therapy. The signaling pathway was determined through RNA sequencing analysis. The results demonstrated that EVA1A can inhibit HBV gene expression in vitro and in vivo. In particular, EVA1A overexpression resulted in accelerated HBV RNA degradation and activation of the PI3K-Akt-mTOR pathway, two processes that directly and indirectly inhibiting HBV gene expression. EVA1A is a promising candidate for treating chronic hepatitis B (CHB). In conclusion, EVA1A is a new host restriction factor that regulates the HBV life cycle via a nonimmune process.

Study on the role of histone epigenetic modification in replication of hepatitis B virus

Hepatitis B virus (HBV) infection is a global health problem and lacks effective therapies in clinic. This study attempted to investigate the role of histone deacetylase 3 (HDAC3) in HBV replication. Cells were treated with 1.3 folds of HBV genome. The expression patterns of HDAC3, miR-29a-3p, and nuclear factor of activated T-cells 5 (NFAT5) in cells were determined by real-time quantitative polymerase chain reaction and Western blot analysis. HBV replication was assessed by measurements of HBV DNA, HBV RNA, hepatitis B surface antigen, and hepatitis B E antigen. After chromatin immunoprecipitation and RNA pull-down assays to testify gene interactions, rescue experiments and animal experiments were performed to assess the role of miR-29a-3p/NFAT5 in HBV replication and the role of HDAC3 in vivo. HDAC3 level was decreased by pHBV1.3 plasmid in a concentration-dependent manner. HDAC3 overexpression can inhibit HBV replication, which was neutralized by miR-29a-3p overexpression or NFAT5 downregulation. Mechanically, HDAC3 overexpression reduced the enrichment of histone 3 lysine 9 acetylation on the miR-29a-3p promoter to inhibit miR-29a-3p expression and then promote NFAT5 transcription. In vivo, HDAC3 restrained HBV replication through the miR-29a-3p/NFAT5 axis. Overall, HDAC3 downregulation was associated with HBV replication and HDAC3 overexpression inhibited HBV replication through H3K9ac/miR-29a-3p/NFAT5.

Mitochondrial Glycerol-3-Phosphate Dehydrogenase Restricts HBV Replication via the TRIM28-Mediated Degradation of HBx.

Hepatitis B virus (HBV) infection affects hepatic metabolism. Serum metabolomics studies have suggested that HBV possibly hijacks the glycerol-3-phosphate (G3P) shuttle. In this study, the two glycerol-3-phosphate dehydrogenases (GPD1 and GPD2) in the G3P shuttle were analyzed for determining their role in HBV replication and the findings revealed that GPD2 and not GPD1 inhibited HBV replication. The knockdown of GPD2 expression upregulated HBV replication, while GPD2 overexpression reduced HBV replication. Moreover, the overexpression of GPD2 significantly reduced HBV replication in hydrodynamic injection-based mouse models. Mechanistically, this inhibitory effect is related to the GPD2-mediated degradation of HBx protein by recruiting the E3 ubiquitin ligase TRIM28 and not to the alterations in G3P metabolism. In conclusion, this study revealed GPD2, a key enzyme in the G3P shuttle, as a host restriction factor in HBV replication. IMPORTANCE The glycerol-3-phosphate (G3P) shuttle is important for the delivery of cytosolic reducing equivalents into mitochondria for oxidative phosphorylation. The study analyzed two key components of the G3P shuttle and identified GPD2 as a restriction factor in HBV replication. The findings revealed a novel mechanism of GPD2-mediated inhibition of HBV replication via the recruitment of TRIM28 for degrading HBx, and the HBx-GPD2 interaction could be another potential therapeutic target for anti-HBV drug development.

Advancing beyond reverse transcriptase inhibitors: The new era of hepatitis B polymerase inhibitors

Hepatitis B virus (HBV) is a genetically diverse blood-borne virus responsible for chronic hepatitis B. The HBV polymerase plays a key role in viral genome replication within the human body and has been identified as a potential drug target for chronic hepatitis B therapeutics. However, available nucleotide reverse transcriptase inhibitors only target the reverse transcriptase domain of the HBV polymerase; they also pose resistance issues and require lifelong treatment that can burden patients financially. In this study, various chemical classes are reviewed that have been developed to target different domains of the HBV polymerase: Terminal protein, which plays a vital role in the formation of the viral DNA; Reverse transcriptase, which is responsible for the synthesis of the viral DNA from RNA, and; Ribonuclease H, which is responsible for degrading the RNA strand in the RNA-DNA duplex formed during the reverse transcription process. Host factors that interact with the HBV polymerase to achieve HBV replication are also reviewed; these host factors can be targeted by inhibitors to indirectly inhibit polymerase functionality. A detailed analysis of the scope and limitations of these inhibitors from a medicinal chemistry perspective is provided. The structure-activity relationship of these inhibitors and the factors that may affect their potency and selectivity are also examined. This analysis will be useful in supporting the further development of these inhibitors and in designing new inhibitors that can inhibit HBV replication more efficiently.

CRISPR/Cas9 for hepatitis B virus infection treatment.

Hepatitis B virus (HBV) infection remains a global health challenge. Despite the availability of effective preventive vaccines, millions of people are at risk of cirrhosis and hepatocellular carcinoma. Current drug therapies inhibit viral replication, slow the progression of liver fibrosis and reduce infectivity, but they rarely remove the covalently sealed circular DNA (cccDNA) of the virus that causes HBV persistence. Alternative treatment strategies, including those based on CRISPR/cas9 knockout virus gene, can effectively inhibit HBV replication, so it has a good prospect. During chronic infection, some virus gene knockouts based on CRISPR/cas9 may even lead to cccDNA inactivation. This paper reviews the progress of different HBV CRISPR/cas9, vectors for delivering to the liver, and the current situation of preclinical and clinical research.

A Historical Overview on the Role of Hepatitis B and C Viruses as Aetiological Factors for Hepatocellular Carcinoma

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the leading cause of hepatocellular carcinoma (HCC) worldwide. Currently, HBV-related HCC predominates in Sub-Saharan Africa and South-East-Asia, while HCV-related HCC predominates in northern Africa and in the western world. Liver cirrhosis is the underlying condition in most HBV cases and in nearly all HCV cases. Several cofactors, viral and non-viral, play a role in the progression toward HCC: dual HBV/HCV infection, HDV, HIV, alcohol intake, smoking, diabetes mellitus, obesity, and NAFLD/NASH. HBV vaccine is effective in preventing both infection and HCC; antiviral drugs may suppress HBV replication and eradicate HCV infection, halting progression to HCC. Inequalities exist between high- and low-income countries with respect to vaccine availability and access to antivirals. These factors represent barriers to the control of HCC incidence. Lack of an effective vaccine against HCV is also a serious barrier to HCV elimination and HCC prevention. The most crucial steps and knowledge that have arisen over time on the association between the two major hepatotropic viruses and HCC are discussed in this historical review.