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Wang J, Xu H, Liu Z, Cao Y, Chen S, Hou R, Zhou Y, Wang Y. Bile acid-microbiota crosstalk in hepatitis B virus infection. J Gastroenterol Hepatol 2024; 39:1509-1516. [PMID: 38721685 DOI: 10.1111/jgh.16604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 04/11/2024] [Accepted: 04/24/2024] [Indexed: 08/10/2024]
Abstract
Hepatitis B virus (HBV) is a hepatotropic non-cytopathic virus characterized by liver-specific gene expression. HBV infection highjacks bile acid metabolism, notably impairing bile acid uptake via sodium taurocholate cotransporting polypeptide (NTCP), which is a functional receptor for HBV entry. Concurrently, HBV infection induces changes in bile acid synthesis and the size of the bile acid pool. Conversely, bile acid facilitates HBV replication and expression through the signaling molecule farnesoid X receptor (FXR), a nuclear receptor activated by bile acid. However, in HepaRG cells and primary hepatocytes, FXR agonists suppress HBV RNA expression and the synthesis and secretion of DNA. In the gut, the size and composition of the bile acid pool significantly influence the gut microbiota. In turn, the gut microbiota impacts bile acid metabolism and innate immunity, potentially promoting HBV clearance. Thus, the bile acid-gut microbiota axis represents a complex and evolving relationship in the context of HBV infection. This review explores the interplay between bile acid and gut microbiota in HBV infection and discusses the development of HBV entry inhibitors targeting NTCP.
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Affiliation(s)
- Jiaxin Wang
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Huimin Xu
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Zixin Liu
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Yutong Cao
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Siyu Chen
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Ruifang Hou
- Hebi Key Laboratory of Liver Disease, Department of Infectious Diseases, People's Hospital of Hebi, Henan University, Hebi, China
| | - Yun Zhou
- Key Laboratory of Receptors-Mediated Gene Regulation, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Yandong Wang
- State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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2
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Lv X, Xiang X, Wu Y, Liu Y, Xu R, Xiang Q, Lai G. GATA binding protein 4 promotes the expression and transcription of hepatitis B virus by facilitating hepatocyte nuclear factor 4 alpha in vitro. Virol J 2021; 18:196. [PMID: 34583732 PMCID: PMC8479913 DOI: 10.1186/s12985-021-01668-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/21/2021] [Indexed: 12/24/2022] Open
Abstract
Background GATA binding protein 4 (GATA4) has been reported as a potential target of gene therapy for hepatocellular carcinoma (HCC). It is well known that the main cause of HCC is the chronic infection of hepatitis B virus (HBV). However, whether the effect of GATA4 on HBV has not yet been reported. Methods In this study, the regulation of GATA4 on HBV was analyzed in vitro. In turn, the effect of HBV on GATA4 was also observed in vitro, in vivo, and clinical HCC patients. Subsequently, we analyzed whether the effect of GATA4 on HBV was related to hepatocyte nuclear factor 4 alpha (HNF4α) in vitro. Results The results showed that GATA4 significantly promoted the secretion of HBV surface antigen (HBsAg) and HBV e antigen in the cell culture medium, improved the replication of HBV genomic DNA, and increased the level of HBV 3.5 kb pre-genomic RNA and HBV total RNA (P < 0.05). Moreover, it was showed that HBV had no significant effect on GATA4 in vitro and in vivo (P > 0.05). At the same time, GATA4 expression was decreased in 78.9% (15/19) of HCC patients regardless of the HBV and HBsAg status. Among them, there were 76.9% (10/13) in HBV-associated patients with HCC (HBV-HCC), and 83.3% (5/6) in non-HBV-HCC patients. In addition, the expression of HNF4α was also up-regulated or down-regulated accordingly when stimulating or interfering with the expression of GATA4. Furthermore, stimulating the expression of HNF4α could only alleviate the HBsAg level and HBV transcription levels, but had no significant effect on GATA4. Conclusions In summary, this study found that GATA4 has a positive effect on HBV, and the potential pathway may be related to another transcription factor HNF4α that regulates HBV.
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Affiliation(s)
- Xiaoqin Lv
- Laboratory Animal Center of Chongqing Medical University, No. 1, Yixueyuan Road, Yuzhong District, Chongqing, 400016, China
| | - Xia Xiang
- Laboratory Animal Center of Chongqing Medical University, No. 1, Yixueyuan Road, Yuzhong District, Chongqing, 400016, China
| | - Yue Wu
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 40010, China
| | - Yang Liu
- LuXian No. 2 High School, Sichuan, 646100, China
| | - Ruqing Xu
- Laboratory Animal Center of Chongqing Medical University, No. 1, Yixueyuan Road, Yuzhong District, Chongqing, 400016, China
| | - Qin Xiang
- Molecular Oncology and Epigenetics Laboratory of the First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China
| | - Guoqi Lai
- Laboratory Animal Center of Chongqing Medical University, No. 1, Yixueyuan Road, Yuzhong District, Chongqing, 400016, China.
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Singh P, Kairuz D, Arbuthnot P, Bloom K. Silencing hepatitis B virus covalently closed circular DNA: The potential of an epigenetic therapy approach. World J Gastroenterol 2021; 27:3182-3207. [PMID: 34163105 PMCID: PMC8218364 DOI: 10.3748/wjg.v27.i23.3182] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/23/2021] [Accepted: 05/07/2021] [Indexed: 02/06/2023] Open
Abstract
Global prophylactic vaccination programmes have helped to curb new hepatitis B virus (HBV) infections. However, it is estimated that nearly 300 million people are chronically infected and have a high risk of developing hepatocellular carcinoma. As such, HBV remains a serious health priority and the development of novel curative therapeutics is urgently needed. Chronic HBV infection has been attributed to the persistence of the covalently closed circular DNA (cccDNA) which establishes itself as a minichromosome in the nucleus of hepatocytes. As the viral transcription intermediate, the cccDNA is responsible for producing new virions and perpetuating infection. HBV is dependent on various host factors for cccDNA formation and the minichromosome is amenable to epigenetic modifications. Two HBV proteins, X (HBx) and core (HBc) promote viral replication by modulating the cccDNA epigenome and regulating host cell responses. This includes viral and host gene expression, chromatin remodeling, DNA methylation, the antiviral immune response, apoptosis, and ubiquitination. Elimination of the cccDNA minichromosome would result in a sterilizing cure; however, this may be difficult to achieve. Epigenetic therapies could permanently silence the cccDNA minichromosome and promote a functional cure. This review explores the cccDNA epigenome, how host and viral factors influence transcription, and the recent epigenetic therapies and epigenome engineering approaches that have been described.
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Affiliation(s)
- Prashika Singh
- Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, University of the Witwatersrand, Johannesburg 2050, Gauteng, South Africa
| | - Dylan Kairuz
- Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, University of the Witwatersrand, Johannesburg 2050, Gauteng, South Africa
| | - Patrick Arbuthnot
- Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, University of the Witwatersrand, Johannesburg 2050, Gauteng, South Africa
| | - Kristie Bloom
- Wits/SAMRC Antiviral Gene Therapy Research Unit, School of Pathology, University of the Witwatersrand, Johannesburg 2050, Gauteng, South Africa
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4
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Yang X, Cai W, Sun X, Bi Y, Zeng C, Zhao X, Zhou Q, Xu T, Xie Q, Sun P, Zhou X. Defined host factors support HBV infection in non-hepatic 293T cells. J Cell Mol Med 2020; 24:2507-2518. [PMID: 31930674 PMCID: PMC7028854 DOI: 10.1111/jcmm.14944] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 11/11/2019] [Accepted: 12/09/2019] [Indexed: 02/05/2023] Open
Abstract
Hepatitis B virus (HBV) is a human hepatotropic virus. However, HBV infection also occurs at extrahepatic sites, but the relevant host factors required for HBV infection in non-hepatic cells are only partially understood. In this article, a non-hepatic cell culture model is constructed by exogenous expression of four host genes (NTCP, HNF4α, RXRα and PPARα) in human non-hepatic 293T cells. This cell culture model supports HBV entry, transcription and replication, as evidenced by the detection of HBV pgRNA, HBV cccDNA, HBsAg, HBeAg, HBcAg and HBVDNA. Our results suggest that the above cellular factors may play a key role in HBV infection of non-hepatic cells. This model will facilitate the identification of host genes that support extrahepatic HBV infection.
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Affiliation(s)
- Xiaoqiang Yang
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
- Medical Research CenterSun Yat‐Sen Memorial HospitalSun Yat‐Sen UniversityGuangzhouChina
| | - Weiwen Cai
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Xiaoyue Sun
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Yanwei Bi
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Chui Zeng
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - XiaoYu Zhao
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Qi Zhou
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Tian Xu
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Qingdong Xie
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Pingnan Sun
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
| | - Xiaoling Zhou
- Stem Cell Research CenterShantou University Medical CollegeShantouChina
- The Center for Reproductive MedicineShantou University Medical CollegeShantouChina
- Guangdong Provincial Key Laboratory of Infectious Diseases and Molecular ImmunopathologyShantou University Medical CollegeShantouChina
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Host Transcription Factors in Hepatitis B Virus RNA Synthesis. Viruses 2020; 12:v12020160. [PMID: 32019103 PMCID: PMC7077322 DOI: 10.3390/v12020160] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 02/06/2023] Open
Abstract
The hepatitis B virus (HBV) chronically infects over 250 million people worldwide and is one of the leading causes of liver cancer and hepatocellular carcinoma. HBV persistence is due in part to the highly stable HBV minichromosome or HBV covalently closed circular DNA (cccDNA) that resides in the nucleus. As HBV replication requires the help of host transcription factors to replicate, focusing on host protein–HBV genome interactions may reveal insights into new drug targets against cccDNA. The structural details on such complexes, however, remain poorly defined. In this review, the current literature regarding host transcription factors’ interactions with HBV cccDNA is discussed.
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6
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Oropeza CE, Tarnow G, Sridhar A, Taha TY, Shalaby RE, McLachlan A. The Regulation of HBV Transcription and Replication. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1179:39-69. [PMID: 31741333 DOI: 10.1007/978-981-13-9151-4_3] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hepatitis B virus (HBV) is a major human pathogen lacking a reliable curative therapy. Current therapeutics target the viral reverse transcriptase/DNA polymerase to inhibit viral replication but generally fail to resolve chronic HBV infections. Due to the limited coding potential of the HBV genome, alternative approaches for the treatment of chronic infections are desperately needed. An alternative approach to the development of antiviral therapeutics is to target cellular gene products that are critical to the viral life cycle. As transcription of the viral genome is an essential step in the viral life cycle, the selective inhibition of viral RNA synthesis is a possible approach for the development of additional therapeutic modalities that might be used in combination with currently available therapies. To address this possibility, a molecular understanding of the relationship between viral transcription and replication is required. The first step is to identify the transcription factors that are the most critical in controlling the levels of HBV RNA synthesis and to determine their in vivo role in viral biosynthesis. Mapping studies in cell culture utilizing reporter gene constructs permitted the identification of both ubiquitous and liver-enriched transcription factors capable of modulating transcription from the four HBV promoters. However, it was challenging to determine their relative importance for viral biosynthesis in the available human hepatoma replication systems. This technical limitation was addressed, in part, by the development of non-hepatoma HBV replication systems where viral biosynthesis was dependent on complementation with exogenously expressed transcription factors. These systems revealed the importance of specific nuclear receptors and hepatocyte nuclear factor 3 (HNF3)/forkhead box A (FoxA) transcription factors for HBV biosynthesis. Furthermore, using the HBV transgenic mouse model of chronic viral infection, the importance of various nuclear receptors and FoxA isoforms could be established in vivo. The availability of this combination of systems now permits a rational approach toward the development of selective host transcription factor inhibitors. This might permit the development of a new class of therapeutics to aid in the treatment and resolution of chronic HBV infections, which currently affects approximately 1 in 30 individuals worldwide and kills up to a million people annually.
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Affiliation(s)
- Claudia E Oropeza
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Grant Tarnow
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Abhayavarshini Sridhar
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Taha Y Taha
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Rasha E Shalaby
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.,Department of Microbiology and Immunology, Faculty of Medicine, Tanta University, Egypt, Egypt
| | - Alan McLachlan
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
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7
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Birkus G, Snyder C, Jordan R, Kobayashi T, Dick R, Puscau V, Li L, Ramirez R, Willkom M, Morikawa Y, Delaney Iv WE, Schmitz U. Anti-HBV activity of retinoid drugs in vitro versus in vivo. Antiviral Res 2019; 169:104538. [PMID: 31226346 DOI: 10.1016/j.antiviral.2019.104538] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/20/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Abstract
We describe here the anti-HBV activity of natural and synthetic retinoids in primary human hepatocytes (PHHs). The most potent compounds inhibited HBsAg, HBeAg, viral RNA and DNA production by HBV infected cells with EC50 values ranging from 0.4 to 2.6 μM. The activity was independent of PHH donor and HBV genotype used in testing. 13-cis retinoic acid (Accutane) was selected for further evaluation in the PXB chimeric mouse model of HBV infection at doses allowing to achieve Accutane peak serum concentrations near its antiviral EC90 and exposures ∼5-fold higher than a typical clinical dose. While these supraclinical exposures of 100 mg/kg/day were well-tolerated by regular Balb/c mice, PXB mice were more sensitive and even a lower those of 60 mg/kg/day led to significant weight loss. Despite dosing at this maximal tolerated dose for 28 days, Accutane failed to show any anti-HBV activity. RAR target engagement was verified using transcriptome analysis of liver samples from treated versus vehicle groups. However, gene expression changes in PXB liver samples were vastly muted when compared to the in vitro PHH system. When comparing transcriptional changes associated with the conditioning of fresh hepatocytes toward enabling HBV infection, we also observed a large number of changes. Noticeably, a significant number of genes that were up- or down-regulated by the conditioning process were down- or up-regulated by HBV infected PHH treatment with Accutane, respectively. While the lack of efficacy in the PXB model may have many explanations, the observed, opposing transcriptional changes upon conditioning PHH and treating these cultured, HBV-infected PHH with Accutane allow for the possibility that the PHH system may yield artificial anti-HBV hits.
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Affiliation(s)
- Gabriel Birkus
- IOCB, Flemingovo nám. 542/2, 160 00, Praha 6, Czech Republic
| | - Chelsea Snyder
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | - Robert Jordan
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | | | - Ryan Dick
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | - Vlad Puscau
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | - Li Li
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | - Ricardo Ramirez
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA
| | | | - Yoshida Morikawa
- Phoenix Bio, 3-4-1, Kagamiyama, Higashi-Hiroshima City, 739-0046, Japan
| | | | - Uli Schmitz
- Gilead Sciences, 333 Lakeside Drive, Foster City, CA, 94494, USA.
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8
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PGC1α Transcriptional Adaptor Function Governs Hepatitis B Virus Replication by Controlling HBcAg/p21 Protein-Mediated Capsid Formation. J Virol 2017; 91:JVI.00790-17. [PMID: 28768874 DOI: 10.1128/jvi.00790-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/30/2017] [Indexed: 02/07/2023] Open
Abstract
In the human hepatoma cell line Huh7, the coexpression of the coactivators peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), cyclic AMP-responsive element binding protein binding protein (CBP), steroid receptor coactivator 1 (SRC1), and protein arginine methyltransferase 1 (PRMT1) only modestly increase hepatitis B virus (HBV) biosynthesis. However, by utilizing the human embryonic kidney cell line HEK293T, it was possible to demonstrate that PGC1α alone can support viral biosynthesis independently of the expression of additional coactivators or transcription factors. In contrast, additional coactivators failed to support robust HBV replication in the absence of PGC1α. These observations indicate that PGC1α represents a novel adaptor molecule capable of recruiting the necessary transcriptional machinery to the HBV nucleocapsid promoter to modestly enhance viral pregenomic 3.5-kb RNA synthesis. Although this change in transcription is associated with a similar modest change in hepatitis B virus core antigen polypeptide (HBcAg/p21) synthesis, it mediates a dramatic increase in viral capsid production and robust viral replication. Therefore, it is apparent that the synthesis of cytoplasmic HBcAg/p21 above a critical threshold level is required for the efficient assembly of HBV replication-competent viral capsids.IMPORTANCE Hepatitis B virus (HBV) is a major human pathogen, and novel targets for the development of additional therapeutic agents are urgently needed. Here we demonstrate that the coactivator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) serves as a unique adaptor molecule for the recruitment of additional coactivator proteins, which can finely regulate HBV transcription. The consequence of this precise regulation of viral RNA levels by PGC1α is a subtle increase in cytoplasmic HBcAg/p21 polypeptide translation, which shifts the equilibrium from dimer formation dramatically in favor of viral capsid assembly. These findings suggest that both PGC1α and capsid assembly may represent attractive targets for the development of antiviral agents against chronic HBV infection.
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9
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Hensel KO, Rendon JC, Navas MC, Rots MG, Postberg J. Virus-host interplay in hepatitis B virus infection and epigenetic treatment strategies. FEBS J 2017; 284:3550-3572. [PMID: 28457020 DOI: 10.1111/febs.14094] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/25/2017] [Accepted: 04/26/2017] [Indexed: 12/11/2022]
Abstract
Worldwide, chronic hepatitis B virus (HBV) infection is a major health problem and no cure exists. Importantly, hepatocyte intrusion by HBV particles results in a complex deregulation of both viral and host cellular genetic and epigenetic processes. Among the attempts to develop novel therapeutic approaches against HBV infection, several options targeting the epigenomic regulation of HBV replication are gaining attention. These include the experimental treatment with 'epidrugs'. Moreover, as a targeted approach, the principle of 'epigenetic editing' recently is being exploited to control viral replication. Silencing of HBV by specific rewriting of epigenetic marks might diminish viral replication, viremia, and infectivity, eventually controlling the disease and its complications. Additionally, epigenetic editing can be used as an experimental tool to increase our limited understanding regarding the role of epigenetic modifications in viral infections. Aiming for permanent epigenetic reprogramming of the viral genome without unspecific side effects, this breakthrough may pave the roads for an ambitious technological pursuit: to start designing a curative approach utilizing manipulative molecular therapies for viral infections in vivo.
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Affiliation(s)
- Kai O Hensel
- HELIOS Medical Centre Wuppertal, Paediatrics Centre, Centre for Clinical & Translational Research (CCTR), Faculty of Health, Centre for Biomedical Education & Research (ZBAF), Witten/Herdecke University, Germany
| | - Julio C Rendon
- Epigenetic Editing, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen (UMCG), The Netherlands.,Grupo de Gastrohepatologia, Facultad de Medicina, Universidad de Antioquia (UdeA), Medellin, Colombia
| | - Maria-Cristina Navas
- Grupo de Gastrohepatologia, Facultad de Medicina, Universidad de Antioquia (UdeA), Medellin, Colombia
| | - Marianne G Rots
- Epigenetic Editing, Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen (UMCG), The Netherlands
| | - Jan Postberg
- HELIOS Medical Centre Wuppertal, Paediatrics Centre, Centre for Clinical & Translational Research (CCTR), Faculty of Health, Centre for Biomedical Education & Research (ZBAF), Witten/Herdecke University, Germany
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10
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Wu S, Kanda T, Nakamoto S, Jiang X, Nakamura M, Sasaki R, Haga Y, Shirasawa H, Yokosuka O. Cooperative effects of hepatitis B virus and TNF may play important roles in the activation of metabolic pathways through the activation of NF-κB. Int J Mol Med 2016; 38:475-81. [PMID: 27315566 PMCID: PMC4935457 DOI: 10.3892/ijmm.2016.2643] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/08/2016] [Indexed: 12/11/2022] Open
Abstract
Elevated levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β are often observed in the sera of hepatitis B virus (HBV)-infected patients. It is well known that these cytokines activate nuclear factor-κB (NF-κB)-signaling, and are associated with endoplasmic reticulum (ER) stress. We investigated whether HBV or HBV X protein (HBx) enhanced the activation of NF-κB in the presence of TNF and/or IL-1β, and their effects on the expression of metabolic pathway-associated genes. We examined whether HBV or HBx enhanced cytokine-induced activation of NF-κB in hepatocytes, using a reporter assay, in the presence or absence of TNF and/or IL-1β. The expression of insulin-like growth factor binding protein 1 (IGFBP1), one of the NF-κB target genes was also examined. The expression of metabolic pathway-associated genes in HepG2 and HepG2.2.15 cells in the presence or absence of TNF was evaluated by RT-qPCR. Human hepatocytes expressed TNF receptors and IL-1 receptors. NF-κB was activated by cooperation between HBx and TNF in human hepatocytes. We observed IGFBP1 expression in HBV infection and that a number of metabolic pathway-associated genes were upregulated in HepG2.2.15 cells, compared with HepG2 cells with or without TNF treatment. We observed the cooperative effects of HBV and TNF which enhanced the activation of NF-κB as well as upregulated the expression of metabolic pathway-associated genes in hepatocytes. These effects may be important in the development of HBV-associated metabolic syndrome.
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Affiliation(s)
- Shuang Wu
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Tatsuo Kanda
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Shingo Nakamoto
- Department of Molecular Virology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Xia Jiang
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Masato Nakamura
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Reina Sasaki
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Yuki Haga
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Hiroshi Shirasawa
- Department of Molecular Virology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
| | - Osamu Yokosuka
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba 260-8677, Japan
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11
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A novel method for nucleos(t)ide analogues susceptibility assay of hepatitis B virus by viral polymerase transcomplementation. Antiviral Res 2015; 126:99-107. [PMID: 26738784 DOI: 10.1016/j.antiviral.2015.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 12/18/2015] [Accepted: 12/22/2015] [Indexed: 02/06/2023]
Abstract
Nucleos(t)ide analogues (NUCs) susceptibility assay is important for the study of hepatitis B virus (HBV) drug resistance. The purpose of susceptibility assay is to test the sensitivity of a specific HBV variant to NUCs in vitro, by which assesses if and to what extent the mutant virus is resistant to a specific NUC. Among the existing susceptibility assay methods, stable cell line expressing the specific variant is one of the commonly used assessment systems based on its high repeatability. However, establishment of stable cell lines expressing individual variant is laborious and time-consuming. In the present study, we developed a novel strategy for rapidly establishing HBV replicating stable cell lines. We first established an acceptor cell line stably transfected with a polymerase-null HBV 1.1mer genome DNA, then lentiviruses expressing different mutant HBV polymerases were transduced into the acceptor cell line respectively. Stable cell lines replicating HBV DNA with the trans-complemented HBV polymerases were established by antibiotics selection. Lamivudine and entecavir susceptibility data from these polymerase-complementing cell lines were validated by comparing with other assays. Taken together, this transcomplementation strategy for establishment of stable cell lines replicating HBV DNA with clinically isolated HBV polymerase provides a new tool for NUC susceptibility assay of HBV.
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Mahajan S, Saini A, Kalra R, Gupta P. Frienemies of infection: A chronic case of host nuclear receptors acting as cohorts or combatants of infection. Crit Rev Microbiol 2014; 42:526-34. [PMID: 25358058 DOI: 10.3109/1040841x.2014.970122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Macrophages and dendritic cells provide critical effector functions to efficiently resist and promptly eliminate infection. Pattern recognition receptors signaling operative in these cell types is imperative for their innate properties. However, it is now emerging that besides these conventional signaling pathways, nuclear receptors coupled gene regulation and transrepression pathways assemble immune regulatory networks. A couple of these networks associated with members of nuclear receptor superfamily decide heterogeneity in macrophages and dendritic cells population and thereby play decisive role in determining protective immunity against bacteria, viruses, fungi, protozoa and helminths. Pathogens also direct shift in the expression of nuclear receptors and their target genes and this is proclaimed to be a sui generis mechanism whereby microbes disconnect the genomic component from the peripheral immune response. Many endogenous and synthetic nuclear receptor ligands have been tested in various in vitro and in vivo infection models to study their effect on pathogen burden. Here, we discuss current advances in our understanding of the composite interactions between nuclear receptor and pathogens and their implications on the causatum infectious diseases.
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Affiliation(s)
- Sahil Mahajan
- a Department of Molecular Biology , CSIR Institute of Microbial Technology , Chandigarh , India
| | - Ankita Saini
- a Department of Molecular Biology , CSIR Institute of Microbial Technology , Chandigarh , India
| | - Rashi Kalra
- a Department of Molecular Biology , CSIR Institute of Microbial Technology , Chandigarh , India
| | - Pawan Gupta
- a Department of Molecular Biology , CSIR Institute of Microbial Technology , Chandigarh , India
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Kanda T, Jiang X, Nakamoto S, Nakamura M, Miyamura T, Wu S, Yokosuka O. Different effects of three interferons L on Toll-like receptor-related gene expression in HepG2 cells. Cytokine 2013; 64:577-83. [PMID: 24041672 DOI: 10.1016/j.cyto.2013.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/07/2013] [Accepted: 08/16/2013] [Indexed: 02/07/2023]
Abstract
IFNL1 (IL29), IFNL2 (IL28A) and IFNL3 (IL28B) might play important roles in anti-viral defense. IFNL3 genotypes have been shown to be associated with hepatitis C spontaneous and treatment-induced viral clearance. The effects of IFNL1, IFNL2 and IFNL3 on innate immunity including Toll-like receptor (TLR)-related pathway in human hepatocytes were examined. After G418 screening, we established the human hepatoma stable cell lines HepG2-IL28A, HepG2-IL28B, and HepG2-IL29, expressing IFNL2, IFNL3, and IFNL1 in conditioned medium, respectively, and a control cell line, HepG2-pcDNA3.1. We performed real-time RT-PCR to investigate 84 Toll-like receptor-related gene expressions in triplicate and, using ddCt methods, compared these gene expressions in each cell line. IFNL2, IFNL3 and IFNL1 were respectively detected by ELISA in HepG2-IL28A, HepG2-IL28B and HepG2-IL29. Compared to HepG2-pcDNA3.1 cells, 17 (20.2%), 11 (13.0%) and 16 genes (19.0%) were up-regulated 1.5-fold or more (p<0.05); 10 (11.9%), 2 (2.3%) and 10 genes (11.9%) were 1.5-fold or more down-regulated (p<0.05) in HepG2-IL28A, HepG2-IL28B and HepG2-IL29, respectively. EIF2AK2 and SARM1 were up-regulated among all cells. Of interest, TLR3, TLR4 and related molecules CXCL10 (IP10), IL6, EIF2K2, IFNB1, and IRF1, important genes in the progression of HCV-related pathogenesis and antiviral activities against HCV, in HepG2-IL28B, presented different profiles from those of HepG2-IL28A and HepG2-IL29. IFNL3 induces interferon-stimulated genes (ISGs) that are reportedly associated with the progression of HCV-related pathogenesis and antiviral activities against HCV. IFNL is a powerful modulator of innate immune response and it is supposed that the 3 IFNLs may play different roles in the antiviral activity against HBV and HCV.
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Affiliation(s)
- Tatsuo Kanda
- Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan.
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Tian X, Zhao F, Cheng Z, Zhou M, Zhi X, Li J, Hu K. GCN5 acetyltransferase inhibits PGC1α-induced hepatitis B virus biosynthesis. Virol Sin 2013; 28:216-22. [PMID: 23913178 DOI: 10.1007/s12250-013-3344-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 06/05/2013] [Indexed: 12/12/2022] Open
Abstract
Hepatitis B virus (HBV) biosynthesis is primarily restricted to hepatocytes due to the governing of liver-enriched nuclear receptors (NRs) on viral RNA synthesis. The liver-enriched NR hepatocyte nuclear factor 4α (HNF4α), the key regulator of genes implicated in hepatic glucose metabolism, is also a primary determinant of HBV pregenomic RNA synthesis and HBV replication. Peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α) coactivates and further enhances the effect of HNF4α on HBV biosynthesis. Here, we showed that the acetyltransferase General Control Non-repressed Protein 5 (GCN5) acetylated PGC1α, leading to alteration of PGC1α from a transcriptionally active state into an inactive state. As a result, the coactivation activity of PGC1α on HBV transcription and replication was suppressed. Apparently, an acetylation site mutant of PGC1α (PGC1αR13) still had coactivation activity as GCN5 could not suppress the coactivation activity of the mutant. Moreover, a catalytically inactive acetyltransferase mutant GCN5m, due to the loss of acetylation activity, failed to inhibit the coactivation function of PGC1α in HBV biosynthesis. Our results demonstrate that GCN5, through its acetyltransferase activity, inhibits PGC1α-induced enhancement of HBV transcription and replication both in vitro and in vivo.
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Affiliation(s)
- Xiaohui Tian
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
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Kitamura K, Wang Z, Chowdhury S, Simadu M, Koura M, Muramatsu M. Uracil DNA glycosylase counteracts APOBEC3G-induced hypermutation of hepatitis B viral genomes: excision repair of covalently closed circular DNA. PLoS Pathog 2013; 9:e1003361. [PMID: 23696735 PMCID: PMC3656096 DOI: 10.1371/journal.ppat.1003361] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 03/31/2013] [Indexed: 12/17/2022] Open
Abstract
The covalently closed circular DNA (cccDNA) of the hepatitis B virus (HBV) plays an essential role in chronic hepatitis. The cellular repair system is proposed to convert cytoplasmic nucleocapsid (NC) DNA (partially double-stranded DNA) into cccDNA in the nucleus. Recently, antiviral cytidine deaminases, AID/APOBEC proteins, were shown to generate uracil residues in the NC-DNA through deamination, resulting in cytidine-to-uracil (C-to-U) hypermutation of the viral genome. We investigated whether uracil residues in hepadnavirus DNA were excised by uracil-DNA glycosylase (UNG), a host factor for base excision repair (BER). When UNG activity was inhibited by the expression of the UNG inhibitory protein (UGI), hypermutation of NC-DNA induced by either APOBEC3G or interferon treatment was enhanced in a human hepatocyte cell line. To assess the effect of UNG on the cccDNA viral intermediate, we used the duck HBV (DHBV) replication model. Sequence analyses of DHBV DNAs showed that cccDNA accumulated G-to-A or C-to-T mutations in APOBEC3G-expressing cells, and this was extensively enhanced by UNG inhibition. The cccDNA hypermutation generated many premature stop codons in the P gene. UNG inhibition also enhanced the APOBEC3G-mediated suppression of viral replication, including reduction of NC-DNA, pre-C mRNA, and secreted viral particle-associated DNA in prolonged culture. Enhancement of APOBEC3G-mediated suppression by UNG inhibition was not observed when the catalytic site of APOBEC3G was mutated. Transfection experiments of recloned cccDNAs revealed that the combination of UNG inhibition and APOBEC3G expression reduced the replication ability of cccDNA. Taken together, these data indicate that UNG excises uracil residues from the viral genome during or after cccDNA formation in the nucleus and imply that BER pathway activities decrease the antiviral effect of APOBEC3-mediated hypermutation.
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Affiliation(s)
- Kouichi Kitamura
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Zhe Wang
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Sajeda Chowdhury
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Miyuki Simadu
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Miki Koura
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
| | - Masamichi Muramatsu
- Department of Molecular Genetics, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan
- * E-mail:
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He F, Chen EQ, Liu L, Zhou TY, Liu C, Cheng X, Liu FJ, Tang H. Inhibition of hepatitis B Virus replication by hepatocyte nuclear factor 4-alpha specific short hairpin RNA. Liver Int 2012; 32:742-51. [PMID: 22340507 DOI: 10.1111/j.1478-3231.2011.02748.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Accepted: 12/27/2011] [Indexed: 02/05/2023]
Abstract
BACKGROUND Previous studies showed that hepatocyte nuclear factor 4α (HNF4α) may play a critical role in hepatitis B virus (HBV) replication. AIMS This study aimed to investigate the effect of knocking down of HNF4α with RNA interference technique on HBV replication in a HBV replication mouse model. METHODS Four HNF4α, specific short hairpin RNA (shRNA)-producing plasmids were constructed. HBV mRNA and DNA replication intermediates were analysed using Northern and Southern blot respectively. The expression of HNF4α and HBV core antigen (HBcAg) was detected using immunohistochemistry technique. RESULTS One of the HNF4α shRNAs, HNF4α shRNA1, efficiently inhibited the expression of HNF4α in HepG2 cells and mice liver. HBV RNA transcripts and DNA replication intermediates in HNF4α shRNA1 group were decreased 67.3 and 76%, respectively, in HepG2 cells, and 68.1 and 70.6% in mice liver respectively. The expression level of HBcAg in the liver was also decreased with the inhibition of HNF4α expression. CONCLUSIONS These results suggested that decreasing of HNF4α expression was associated with the reduced level of HBV replication in HepG2 cells and mice liver. These data indicated that HNF4α played a critical role in HBV replication in vivo, and HNF4α shRNA could inhibit HBV replication in vivo.
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Affiliation(s)
- Fang He
- Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, China
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Limited effects of bile acids and small heterodimer partner on hepatitis B virus biosynthesis in vivo. J Virol 2011; 86:2760-8. [PMID: 22171277 DOI: 10.1128/jvi.06742-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Multiple nuclear receptors, including hepatocyte nuclear factor 4α (HNF4α), retinoid X receptor α (RXRα) plus peroxisome proliferator-activated receptor α (PPARα), RXRα plus farnesoid X receptor α (FXRα), liver receptor homolog 1 (LRH1), and estrogen-related receptors (ERRs), have been shown to support efficient viral biosynthesis in nonhepatoma cells in the absence of additional liver-enriched transcription factors. Although HNF4α has been shown to be critical for the developmental expression of hepatitis B virus (HBV) biosynthesis in the liver, the relative importance of the various nuclear receptors capable of supporting viral transcription and replication in the adult in vivo has not been clearly established. To investigate the role of the nuclear receptor FXR and the corepressor small heterodimer partner (SHP) in viral biosynthesis in vivo, SHP-expressing and SHP-null HBV transgenic mice were fed a bile acid-supplemented diet. The increased FXR activity and SHP expression levels resulting from bile acid treatment did not greatly modulate HBV RNA and DNA synthesis. Therefore, FXR and SHP appear to play a limited role in modulating HBV biosynthesis, suggesting that alternative nuclear receptors are more critical determinants of viral transcription in the HBV transgenic mouse model of chronic viral infection. These observations suggest that hepatic bile acid levels or therapeutic agents targeting FXR may not greatly modulate viremia during natural infection.
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Miller MS, Mymryk JS. An unhealthy relationship: viral manipulation of the nuclear receptor superfamily. Future Microbiol 2011; 6:999-1019. [PMID: 21958141 DOI: 10.2217/fmb.11.80] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The nuclear receptor (NR) superfamily is a diverse group of over 50 proteins whose function is to regulate the transcription of a vast array of cellular genes. These proteins are able to tune transcription over an extremely dynamic range due to the fact that they may act as either transcriptional activators or repressors depending on promoter context and ligand status. Due to these unique properties, diverse families of viruses have evolved strategies to exploit NRs in order to regulate expression of their own genes and to optimize the cellular milieu to facilitate the viral lifecycle. While the specific NRs targeted by these viruses vary, the strategies used to target them are common. This is accomplished at the cis-level by incorporation of nuclear receptor response elements into the viral genome and at the trans-level by viral proteins that target NRs directly or indirectly to modulate their function. The specific NR(s) targeted by a particular virus are likely to be reflective of the tissue tropism of the virus in question. Thus, the essential role played by NRs in the replication cycles of such diverse viruses underscores the importance of understanding their functions in the context of specific infections. This knowledge will allow appropriate considerations to be made when treating infected individuals with hormone-associated diseases and will potentially assist in the rational design of novel antiviral therapeutics.
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Affiliation(s)
- Matthew S Miller
- Department of Microbiology & Immunology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, N6A 5C1, Canada
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Ahn YC, Seo JW, Choi JG, Jang WC. Detection of Hepatitis B Virus by LAMP and DHPLC. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2011. [DOI: 10.5012/jkcs.2011.55.2.262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Hepatitis B virus (HBV) is tightly controlled by a number of noncytotoxic mechanisms. This control occurs within the host hepatocyte at different steps of the HBV replication cycle. HBV persists by establishing a nuclear minichromosome, HBV cccDNA, serving as a transcription template for the viral pregenome and viral mRNAs. Nucleoside/nucleotide analogues widely used for antiviral therapy as well as most antiviral cytokines act at steps after transcription of HBV RNAs and thus can control virus replication but do not directly affect its gene expression. Control of HBV at the level of transcription in contrast is able to restrict both, HBV replication and gene expression. In the review, we focus on how HBV is controlled at the level of transcription. We discuss how the composition of transcription factors determines HBV gene expression and replication and how this may be influenced by antivirally active substances, e.g. the cytokine IL-6 or helioxanthin analogues, or by the differentiation state of the hepatocyte.
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Affiliation(s)
- M Quasdorff
- Department of Gastroenterology and Hepatology, University Hospital Cologne, Germany
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21
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Abstract
Hepatitis B virus (HBV) is tightly controlled by a number of noncytotoxic mechanisms. This control occurs within the host hepatocyte at different steps of the HBV replication cycle. HBV persists by establishing a nuclear minichromosome, HBV cccDNA, serving as a transcription template for the viral pregenome and viral mRNAs. Nucleoside/nucleotide analogues widely used for antiviral therapy as well as most antiviral cytokines act at steps after transcription of HBV RNAs and thus can control virus replication but do not directly affect its gene expression. Control of HBV at the level of transcription in contrast is able to restrict both, HBV replication and gene expression. In the review, we focus on how HBV is controlled at the level of transcription. We discuss how the composition of transcription factors determines HBV gene expression and replication and how this may be influenced by antivirally active substances, e.g. the cytokine IL-6 or helioxanthin analogues, or by the differentiation state of the hepatocyte.
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Affiliation(s)
- M Quasdorff
- Department of Gastroenterology and Hepatology, University Hospital Cologne, Germany
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Kim HY, Cho HK, Choi YH, Lee KS, Cheong J. Bile acids increase hepatitis B virus gene expression and inhibit interferon-α activity. FEBS J 2010; 277:2791-802. [DOI: 10.1111/j.1742-4658.2010.07695.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Reese V, Ondracek C, Rushing C, Li L, Oropeza CE, McLachlan A. Multiple nuclear receptors may regulate hepatitis B virus biosynthesis during development. Int J Biochem Cell Biol 2009; 43:230-7. [PMID: 19941970 DOI: 10.1016/j.biocel.2009.11.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 09/22/2009] [Accepted: 11/18/2009] [Indexed: 01/01/2023]
Abstract
Hepatitis B virus (HBV) replicates by the reverse transcription of the viral 3.5 kb pregenomic RNA. Therefore the level of expression of this transcript in the liver is a primary determinant of HBV biosynthesis. In vivo neonatal transcription of the HBV 3.5 kb pregenomic RNA is developmental regulated by hepatocyte nuclear factor 4α (HNF4α). In addition, viral biosynthesis in non-hepatoma cells can be supported directly by this nuclear receptor. However HBV transcription and replication can be supported by additional nuclear receptors including the retinoid X receptor α/peroxisome proliferator-activated receptor α (RXRα/PPARα), retinoid X receptor α/farnesoid X receptor α (RXRα/FXRα), liver receptor homolog 1 (LRH1) and estrogen-related receptors (ERR) in non-hepatoma cells. Therefore during neonatal liver development, HNF4α may progressively activate viral transcription and replication by binding directly to the proximal HNF4α recognition sequence within the nucleocapsid promoter. Alternatively, HNF4α may support viral biosynthesis in vivo indirectly by activating a network of liver-enriched nuclear receptors that, in combination, direct HBV 3.5 kb pregenomic RNA transcription and replication.
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Affiliation(s)
- Vanessa Reese
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612-7344, USA.
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Distinct regulation of hepatitis B virus biosynthesis by peroxisome proliferator-activated receptor gamma coactivator 1alpha and small heterodimer partner in human hepatoma cell lines. J Virol 2009; 83:12545-51. [PMID: 19793803 DOI: 10.1128/jvi.01624-09] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The human hepatoma cell lines HepG2 and Huh7 have been used extensively to study hepatitis B virus (HBV) transcription and replication. Both cell lines support transcription of the 3.5-kb viral pregenomic RNA and subsequent viral DNA synthesis by reverse transcription. The effects of the coactivator peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC1alpha) and corepressor small heterodimer partner (SHP) on HBV transcription and replication mediated by nuclear receptors were examined in the context of individual nuclear receptors in nonhepatoma cells and in hepatoma cells in an attempt to determine the relative contribution of the various nuclear receptors to viral biosynthesis in the hepatoma cells. PGC1alpha and SHP modulated viral biosynthesis differently in the human hepatoma cell lines HepG2 and Huh7, indicating distinct modes of transcriptional regulation. Consistent with this suggestion, it appears that retinoid X receptor alpha/farnesoid X receptor alpha and liver receptor homolog 1 or estrogen-related receptor beta (ERRbeta) may contribute to the majority of the viral replication observed in HepG2 cells, whereas ERRalpha and ERRgamma are probably responsible for the majority of viral biosynthesis in Huh7 cells. Therefore, this approach indicates that the transcriptional regulation of HBV biosynthesis in HepG2 and Huh7 cells is primarily controlled by different transcription factors.
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Peroxisome proliferator-activated receptor gamma Coactivator 1alpha and small heterodimer partner differentially regulate nuclear receptor-dependent hepatitis B virus biosynthesis. J Virol 2009; 83:12535-44. [PMID: 19793822 DOI: 10.1128/jvi.01623-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Hepatitis B virus (HBV) biosynthesis involves the transcription of the 3.5-kb viral pregenomic RNA, followed by its reverse transcription into viral DNA. Consequently, the modulation of viral transcription influences the level of virus production. Nuclear receptors are the only transcription factors known to support viral pregenomic RNA transcription and replication. The coactivator peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC1alpha) and corepressor small heterodimer partner (SHP) have central roles in regulating energy homeostasis in the liver by modulating the transcriptional activities of nuclear receptors. Therefore, the effect of PGC1alpha and SHP on HBV transcription and replication mediated by nuclear receptors was examined in the context of individual nuclear receptors in nonhepatoma cells and in hepatoma cells. This analysis indicated that viral replication mediated by hepatocyte nuclear factor 4alpha, retinoid X receptor alpha (RXRalpha) plus peroxisome proliferator-activated receptor alpha (PPARalpha), and estrogen-related receptor (ERR) displayed differential sensitivity to PGC1alpha activation and SHP inhibition. The effects of PGC1alpha and SHP on viral biosynthesis in the human hepatoma cell line Huh7 were similar to those observed in the nonhepatoma cells expressing ERRalpha and ERRgamma. This suggests that these nuclear receptors, potentially in combination with RXRalpha plus PPARalpha, may have a major role in governing HBV transcription and replication in this cell line. Additionally, this functional approach may help to distinguish the transcription factors in various liver cells governing viral biosynthesis under a variety of physiologically relevant conditions.
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Peroxisome proliferator-activated receptors in HBV-related infection. PPAR Res 2009; 2009:145124. [PMID: 19365584 PMCID: PMC2667936 DOI: 10.1155/2009/145124] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 02/18/2009] [Indexed: 12/18/2022] Open
Abstract
Thirty years after its discovery, the hepatitis B virus (HBV) still remains a major global public health problem. Worldwide, two billion subjects have been infected, 350 million have a chronic infection and more than 600 000 die annually of HBV-related liver disease or hepatocellular carcinoma; new infections occur because of the presence of a large reservoir of chronic carriers of the virus. Since a decade several studies describe the interrelations between HBV and nuclear receptors and more particularly the peroxisome proliferator-activated receptors (PPARs). After a brief introduction, this review will make a rapid description of HBV incidence and biology. Then a report of the literature on the role of PPARs on viral transcription and replication will be developed. Finally, the role of HBV on PPARγ expression and activity will be discussed. Concluding remarks and perspectives will close this review.
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Transactivation of the hepatitis B virus core promoter by the nuclear receptor FXRalpha. J Virol 2008; 82:10832-40. [PMID: 18768987 DOI: 10.1128/jvi.00883-08] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Hepatitis B virus (HBV) core promoter activity is positively and negatively regulated by nuclear receptors, a superfamily of ligand-activated transcription factors, via cis-acting sequences located in the viral genome. In this study, we investigated the role of farnesoid X receptor alpha (FXRalpha) in modulating transcription from the HBV core promoter. FXRalpha is a liver-enriched nuclear receptor activated by bile acids recognizing hormone response elements by forming heterodimers with retinoid X receptor alpha (RXRalpha). Electrophoretic mobility shift assays demonstrated that FXRalpha-RXRalpha heterodimers can bind two motifs on the HBV enhancer II and core promoter regions, presenting high homology to the consensus (AGGTCA) inverted repeat FXRalpha response elements. In transient transfection of the human hepatoma cell line Huh-7, bile acids enhanced the activity of a luciferase reporter containing the HBV enhancer II and core promoter sequences through FXRalpha. Moreover, using a greater-than-genome-length HBV construct, we showed that FXRalpha also increased synthesis of the viral pregenomic RNA and DNA replication intermediates. The data strongly suggest that FXRalpha is another member of the nuclear receptor superfamily implicated in the regulation of HBV core promoter activity and that bile acids could play an important role in the natural history of HBV infection.
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