1
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Prescott NA, Mansisidor A, Bram Y, Biaco T, Rendleman J, Faulkner SC, Lemmon AA, Lim C, Hamard PJ, Koche RP, Risca VI, Schwartz RE, David Y. A nucleosome switch primes Hepatitis B Virus infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.03.03.531011. [PMID: 38915612 PMCID: PMC11195122 DOI: 10.1101/2023.03.03.531011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Chronic hepatitis B virus (HBV) infection is an incurable global health threat responsible for causing liver disease and hepatocellular carcinoma. During the genesis of infection, HBV establishes an independent minichromosome consisting of the viral covalently closed circular DNA (cccDNA) genome and host histones. The viral X gene must be expressed immediately upon infection to induce degradation of the host silencing factor, Smc5/6. However, the relationship between cccDNA chromatinization and X gene transcription remains poorly understood. Establishing a reconstituted viral minichromosome platform, we found that nucleosome occupancy in cccDNA drives X transcription. We corroborated these findings in cells and further showed that the chromatin destabilizing molecule CBL137 inhibits X transcription and HBV infection in hepatocytes. Our results shed light on a long-standing paradox and represent a potential new therapeutic avenue for the treatment of chronic HBV infection.
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Affiliation(s)
- Nicholas A. Prescott
- Tri-Institutional PhD Program in Chemical Biology; New York, NY 10065, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
| | - Andrés Mansisidor
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University; New York, NY 10065, USA
- These authors contributed equally
| | - Yaron Bram
- Division of Gastroenterology & Hepatology, Department of Medicine, Weill Cornell Medicine; New York, NY 10065, USA
- These authors contributed equally
| | - Tracy Biaco
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
- Department of Pharmacology, Weill Cornell Medicine; New York, NY 10065, USA
- These authors contributed equally
| | - Justin Rendleman
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University; New York, NY 10065, USA
| | - Sarah C. Faulkner
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
| | - Abigail A. Lemmon
- Tri-Institutional PhD Program in Chemical Biology; New York, NY 10065, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
| | - Christine Lim
- Division of Gastroenterology & Hepatology, Department of Medicine, Weill Cornell Medicine; New York, NY 10065, USA
| | - Pierre-Jacques Hamard
- Epigenetics Research Innovation Lab, Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
| | - Richard P. Koche
- Epigenetics Research Innovation Lab, Center for Epigenetics Research, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
| | - Viviana I. Risca
- Laboratory of Genome Architecture and Dynamics, The Rockefeller University; New York, NY 10065, USA
| | - Robert E. Schwartz
- Division of Gastroenterology & Hepatology, Department of Medicine, Weill Cornell Medicine; New York, NY 10065, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine; New York, NY 10065, USA
| | - Yael David
- Tri-Institutional PhD Program in Chemical Biology; New York, NY 10065, USA
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center; New York, NY 10065, USA
- Department of Pharmacology, Weill Cornell Medicine; New York, NY 10065, USA
- Lead Contact
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2
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Guan G, Abulaiti A, Qu C, Chen CC, Gu Z, Yang J, Zhang T, Chen X, Zhou Z, Lu F, Chen X. Multi-omics panoramic analysis of HBV integration, transcriptional regulation, and epigenetic modifications in PLC/PRF/5 cell line. J Med Virol 2024; 96:e29614. [PMID: 38647071 DOI: 10.1002/jmv.29614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 04/04/2024] [Accepted: 04/08/2024] [Indexed: 04/25/2024]
Abstract
The clearance or transcriptional silencing of integrated HBV DNA is crucial for achieving a functional cure in patients with chronic hepatitis B and reducing the risk of hepatocellular carcinoma development. The PLC/PRF/5 cell line is commonly used as an in vitro model for studying HBV integration. In this study, we employed a range of multi-omics techniques to gain a panoramic understanding of the characteristics of HBV integration in PLC/PRF/5 cells and to reveal the transcriptional regulatory mechanisms of integrated HBV DNA. Transcriptome long-read sequencing (ONT) was conducted to analyze and characterize the transcriptional activity of different HBV DNA integration sites in PLC/PRF/5 cells. Additionally, we collected data related to epigenetic regulation, including whole-genome bisulfite sequencing (WGBS), histone chromatin immunoprecipitation sequencing (ChIP-seq), and assays for transposase-accessible chromatin using sequencing (ATAC-seq), to explore the potential mechanisms involved in the transcriptional regulation of integrated HBV DNA. Long-read RNA sequencing analysis revealed significant transcriptional differences at various integration sites in the PLC/PRF/5 cell line, with higher HBV DNA transcription levels at integration sites on chr11, chr13, and the chr13/chr5 fusion chromosome t (13:5). Combining long-read DNA and RNA sequencing results, we found that transcription of integrated HBV DNA generally starts downstream of the SP1, SP2, or XP promoters. ATAC-seq data confirmed that chromatin accessibility has limited influence on the transcription of integrated HBV DNA in the PLC/PRF/5 cell line. Analysis of WGBS data showed that the methylation intensity of integrated HBV DNA was highly negatively correlated with its transcription level (r = -0.8929, p = 0.0123). After AzaD treatment, the transcription level of integrated HBV DNA significantly increased, especially for the integration chr17, which had the highest level of methylation. Through ChIP-seq data, we observed the association between histone modification of H3K4me3 and H3K9me3 with the transcription of integrated HBV DNA. Our findings suggest that the SP1, SP2 and XP in integrated HBV DNA, methylation level of surrounding host chromosome, and histone modifications affect the transcription of integrated HBV DNA in PLC/PRF/5 cells. This provides important clues for future studies on the expression and regulatory mechanisms of integrated HBV.
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Affiliation(s)
- Guiwen Guan
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Abudurexiti Abulaiti
- Department of Cell Biology, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Chenxiao Qu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Chia-Chen Chen
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
- National Heart and Lung Institute Faculty of Medicine (NHLI), Imperial College London, London, UK
| | - Zhiqiang Gu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Jing Yang
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China
| | - Ting Zhang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xiaojie Chen
- Liver Transplantation Center, National Clinical Research Center for Digestive Diseases, Beijing Friendship Hospital, Capital Medical University, Beijing, China
- Clinical Research Center for Pediatric Liver Transplantation of Capital Medical University, Beijing, China
| | - Zhao Zhou
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Fengmin Lu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
| | - Xiangmei Chen
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University, Beijing, China
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3
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Zhang Y, Yuan X, Wang J, Han M, Lu H, Wang Y, Liu S, Yang S, Xing HC, Cheng J. TRPV4 promotes HBV replication and capsid assembly via methylation modification of H3K4 and HBc ubiquitin. J Med Virol 2024; 96:e29510. [PMID: 38573018 DOI: 10.1002/jmv.29510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 02/21/2024] [Accepted: 02/25/2024] [Indexed: 04/05/2024]
Abstract
Hepatitis B virus (HBV) infection poses a significant burden on global public health. Unfortunately, current treatments cannot fully alleviate this burden as they have limited effect on the transcriptional activity of the tenacious covalently closed circular DNA (cccDNA) responsible for viral persistence. Consequently, the HBV life cycle should be further investigated to develop new anti-HBV pharmaceutical targets. Our previous study discovered that the host gene TMEM203 hinders HBV replication by participating in calcium ion regulation. The involvement of intracellular calcium in HBV replication has also been confirmed. In this study, we found that transient receptor potential vanilloid 4 (TRPV4) notably enhances HBV reproduction by investigating the effects of several calcium ion-related molecules on HBV replication. The in-depth study showed that TRPV4 promotes hepatitis B core/capsid protein (HBc) protein stability through the ubiquitination pathway and then promotes the nucleocapsid assembly. HBc binds to cccDNA and reduces the nucleosome spacing of the cccDNA-histones complex, which may regulate HBV transcription by altering the nucleosome arrangement of the HBV genome. Moreover, our results showed that TRPV4 promotes cccDNA-dependent transcription by accelerating the methylation modification of H3K4. In conclusion, TRPV4 could interact with HBV core protein and regulate HBV during transcription and replication. These data suggest that TRPV4 exerts multifaceted HBV-related synergistic factors and may serve as a therapeutic target for CHB.
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Affiliation(s)
- Yu Zhang
- Peking University Ditan Teaching Hospital, Beijing, China
- Department of Hepatology, Beijing Ditan Hospital of Capital Medical University, Beijing, China
| | - Xiaoxue Yuan
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China
| | - Jun Wang
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Emerging Infectious Diseases, Peking University Ditan Teaching Hospital, Beijing, China
| | - Ming Han
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China
| | - Hongping Lu
- Beijing Pan-Asia Tongze Institute of Biomedicine Co, Ltd, Beijing, China
| | - Yun Wang
- Department of Hepatology, Beijing Ditan Hospital of Capital Medical University, Beijing, China
- Beijing Key Laboratory of Emerging Infectious Diseases, The First Section of Liver Disease, Beijing Ditan Hospital, Capital Medical University, Beijing, China
| | - Shunai Liu
- Beijing Key Laboratory of Emerging Infectious Diseases, Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, Beijing, China
| | - Song Yang
- Department of Hepatology, Beijing Ditan Hospital of Capital Medical University, Beijing, China
| | - Hui-Chun Xing
- Department of Hepatology, Beijing Ditan Hospital of Capital Medical University, Beijing, China
| | - Jun Cheng
- Peking University Ditan Teaching Hospital, Beijing, China
- Department of Hepatology, Beijing Ditan Hospital of Capital Medical University, Beijing, China
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4
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Harris JM, Magri A, Faria AR, Tsukuda S, Balfe P, Wing PAC, McKeating JA. Oxygen-dependent histone lysine demethylase 4 restricts hepatitis B virus replication. J Biol Chem 2024; 300:105724. [PMID: 38325742 PMCID: PMC10914488 DOI: 10.1016/j.jbc.2024.105724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/25/2024] [Accepted: 02/01/2024] [Indexed: 02/09/2024] Open
Abstract
Mammalian cells have evolved strategies to regulate gene expression when oxygen is limited. Hypoxia-inducible factors (HIF) are the major transcriptional regulators of host gene expression. We previously reported that HIFs bind and activate hepatitis B virus (HBV) DNA transcription under low oxygen conditions; however, the global cellular response to low oxygen is mediated by a family of oxygenases that work in concert with HIFs. Recent studies have identified a role for chromatin modifiers in sensing cellular oxygen and orchestrating transcriptional responses, but their role in the HBV life cycle is as yet undefined. We demonstrated that histone lysine demethylase 4 (KDM4) can restrict HBV, and pharmacological or oxygen-mediated inhibition of the demethylase increases viral RNAs derived from both episomal and integrated copies of the viral genome. Sequencing studies demonstrated that KDM4 is a major regulator of the hepatic transcriptome, which defines hepatocellular permissivity to HBV infection. We propose a model where HBV exploits cellular oxygen sensors to replicate and persist in the liver. Understanding oxygen-dependent pathways that regulate HBV infection will facilitate the development of physiologically relevant cell-based models that support efficient HBV replication.
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Affiliation(s)
- James M Harris
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Andrea Magri
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ana Rita Faria
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Senko Tsukuda
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter Balfe
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter A C Wing
- Nuffield Department of Medicine, University of Oxford, Oxford, UK; Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, UK.
| | - Jane A McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, UK; Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, UK.
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5
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Loukachov V, van Dort K, Erken R, Reesink HW, Kootstra N. Reply. Hepatology 2023; 77:E21. [PMID: 35809235 DOI: 10.1002/hep.32656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 01/28/2023]
Affiliation(s)
- Vladimir Loukachov
- Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute , University of Amsterdam , Amsterdam , The Netherlands
| | - Karel van Dort
- Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute , University of Amsterdam , Amsterdam , The Netherlands
| | - Robin Erken
- Department of Gastroenterology and Hepatology, Amsterdam Gastroenterology Endocrinology Metabolism , Amsterdam UMC, Location AMC , Amsterdam , The Netherlands
| | - Henk W Reesink
- Department of Gastroenterology and Hepatology , Leiden University Medical Center , Leiden , The Netherlands
| | - Neeltje Kootstra
- Department of Experimental Immunology, Amsterdam UMC, Location AMC, Amsterdam Infection & Immunity Institute , University of Amsterdam , Amsterdam , The Netherlands
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6
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Abulaiti A, Gu Z, Jiang Q, Huang H, Lu F. Letter to the editor: Low sensitivity of RT-Alu-PCR in detection of HBV integrated chimeric transcripts. Hepatology 2023; 77:E19-E20. [PMID: 35808857 DOI: 10.1002/hep.32654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/16/2022] [Indexed: 01/28/2023]
Affiliation(s)
- Abudurexiti Abulaiti
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China
| | - Zhiqiang Gu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China
| | - Qianqian Jiang
- Hepatology Institute , Peking University People's Hospital , Beijing , China
| | - Hongxin Huang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China
| | - Fengmin Lu
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences , Peking University Health Science Center , Beijing , China.,Hepatology Institute , Peking University People's Hospital , Beijing , China
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7
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The scientific basis of combination therapy for chronic hepatitis B functional cure. Nat Rev Gastroenterol Hepatol 2023; 20:238-253. [PMID: 36631717 DOI: 10.1038/s41575-022-00724-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/24/2022] [Indexed: 01/13/2023]
Abstract
Functional cure of chronic hepatitis B (CHB) - or hepatitis B surface antigen (HBsAg) loss after 24 weeks off therapy - is now the goal of treatment, but is rarely achieved with current therapy. Understanding the hepatitis B virus (HBV) life cycle and immunological defects that lead to persistence can identify targets for novel therapy. Broadly, treatments fall into three categories: those that reduce viral replication, those that reduce antigen load and immunotherapies. Profound viral suppression alone does not achieve quantitative (q)HBsAg reduction or HBsAg loss. Combining nucleos(t)ide analogues and immunotherapy reduces qHBsAg levels and induces HBsAg loss in some patients, particularly those with low baseline qHBsAg levels. Even agents that are specifically designed to reduce viral antigen load might not be able to achieve sustained HBsAg loss when used alone. Thus, rationale exists for the use of combinations of all three therapy types. Monitoring during therapy is important not just to predict HBsAg loss but also to understand mechanisms of HBsAg loss using viral and immunological biomarkers, and in selected cases intrahepatic sampling. We consider various paths to functional cure of CHB and the need to individualize treatment of this heterogeneous infection until a therapeutic avenue for all patients with CHB is available.
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8
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Hepatitis B virus X protein counteracts high mobility group box 1 protein-mediated epigenetic silencing of covalently closed circular DNA. PLoS Pathog 2022; 18:e1010576. [PMID: 35679251 PMCID: PMC9182688 DOI: 10.1371/journal.ppat.1010576] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 05/06/2022] [Indexed: 11/19/2022] Open
Abstract
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), serving as the viral persistence form and transcription template of HBV infection, hijacks host histone and non-histone proteins to form a minichromosome and utilizes posttranslational modifications (PTMs) "histone code" for its transcriptional regulation. HBV X protein (HBx) is known as a cccDNA transcription activator. In this study we established a dual system of the inducible reporter cell lines modelling infection with wildtype (wt) and HBx-null HBV, both secreting HA-tagged HBeAg as a semi-quantitative marker for cccDNA transcription. The cccDNA-bound histone PTM profiling of wt and HBx-null systems, using chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR), confirmed that HBx is essential for maintenance of cccDNA at transcriptionally active state, characterized by active histone PTM markers. Differential proteomics analysis of cccDNA minichromosome established in wt and HBx-null HBV cell lines revealed group-specific hits. One of the hits in HBx-deficient condition was a non-histone host DNA-binding protein high mobility group box 1 (HMGB1). Its elevated association to HBx-null cccDNA was validated by ChIP-qPCR assay in both the HBV stable cell lines and infection systems in vitro. Furthermore, experimental downregulation of HMGB1 in HBx-null HBV inducible and infection models resulted in transcriptional re-activation of the cccDNA minichromosome, accompanied by a switch of the cccDNA-associated histones to euchromatic state with activating histone PTMs landscape and subsequent upregulation of cccDNA transcription. Mechanistically, HBx interacts with HMGB1 and prevents its binding to cccDNA without affecting the steady state level of HMGB1. Taken together, our results suggest that HMGB1 is a novel host restriction factor of HBV cccDNA with epigenetic silencing mechanism, which can be counteracted by viral transcription activator HBx.
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9
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Boettler T, Gill US, Allweiss L, Pollicino T, Tavis JE, Zoulim F. Assessing immunological and virological responses in the liver: implications for the cure of chronic hepatitis B virus infection. JHEP REPORTS : INNOVATION IN HEPATOLOGY 2022; 4:100480. [PMID: 35493765 PMCID: PMC9039841 DOI: 10.1016/j.jhepr.2022.100480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/11/2022]
Abstract
Cure from chronic HBV infection is rare with current therapies. Basic research has helped to fundamentally improve our knowledge of the viral life cycle and virus-host interactions, and provided the basis for several novel drug classes that are currently being developed or are being tested in clinical trials. While these novel compounds targeting the viral life cycle or antiviral immune responses hold great promise, we are still lacking a comprehensive understanding of the immunological and virological processes that occur at the site of infection, the liver. At the International Liver Congress 2021 (ILC 2021), a research think tank on chronic HBV infection focused on mechanisms within the liver that facilitate persistent infection and looked at the research questions that need to be addressed to fill knowledge gaps and identify novel therapeutic strategies. Herein, we summarise the discussion by the think tank and identify the key basic research questions that must be addressed in order to develop more effective strategies for the functional cure of HBV infection.
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10
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Zhang X, Wang Y, Yang G. Research progress in hepatitis B virus covalently closed circular DNA. Cancer Biol Med 2021; 19:j.issn.2095-3941.2021.0454. [PMID: 34931766 PMCID: PMC9088183 DOI: 10.20892/j.issn.2095-3941.2021.0454] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/16/2021] [Indexed: 11/28/2022] Open
Abstract
Hepatitis B virus (HBV) infections are a global public health issue. HBV covalently closed circular DNA (cccDNA), the template for the transcription of viral RNAs, is a key factor in the HBV replication cycle. Notably, many host factors involved in HBV cccDNA epigenetic modulation promote the development of hepatocellular carcinoma (HCC). The HBV cccDNA minichromosome is a clinical obstacle that cannot be efficiently eliminated. In this review, we provide an update on the advances in research on HBV cccDNA and further discuss factors affecting the modulation of HBV cccDNA. Hepatitis B virus X protein (HBx) contributes to HBV cccDNA transcription and the development of hepatocarcinogenesis through modulating host epigenetic regulatory factors, thus linking the cccDNA to hepatocarcinogenesis. The measurable serological biomarkers of continued transcription of cccDNA, the effects of anti-HBV drugs on cccDNA, and potential therapeutic strategies targeting cccDNA are discussed in detail. Thus, this review describes new insights into HBV cccDNA mechanisms and therapeutic strategies for cleaning cccDNA, which will benefit patients with liver diseases.
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Affiliation(s)
- Xiaodong Zhang
- Department of Gastrointestinal Cancer Biology, Liver Cancer Center, Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yufei Wang
- Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Guang Yang
- Department of Gastrointestinal Cancer Biology, Liver Cancer Center, Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, Tianjin’s Clinical Research Center for Cancer, Tianjin 300060, China
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11
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Cai Q, Gan C, Tang C, Wu H, Gao J. Mechanism and Therapeutic Opportunities of Histone Modifications in Chronic Liver Disease. Front Pharmacol 2021; 12:784591. [PMID: 34887768 PMCID: PMC8650224 DOI: 10.3389/fphar.2021.784591] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/08/2021] [Indexed: 02/05/2023] Open
Abstract
Chronic liver disease (CLD) represents a global health problem, accounting for the heavy burden of disability and increased health care utilization. Epigenome alterations play an important role in the occurrence and progression of CLD. Histone modifications, which include acetylation, methylation, and phosphorylation, represent an essential part of epigenetic modifications that affect the transcriptional activity of genes. Different from genetic mutations, histone modifications are plastic and reversible. They can be modulated pharmacologically without changing the DNA sequence. Thus, there might be chances to establish interventional solutions by targeting histone modifications to reverse CLD. Here we summarized the roles of histone modifications in the context of alcoholic liver disease (ALD), metabolic associated fatty liver disease (MAFLD), viral hepatitis, autoimmune liver disease, drug-induced liver injury (DILI), and liver fibrosis or cirrhosis. The potential targets of histone modifications for translation into therapeutics were also investigated. In prospect, high efficacy and low toxicity drugs that are selectively targeting histone modifications are required to completely reverse CLD and prevent the development of liver cirrhosis and malignancy.
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Affiliation(s)
- Qiuyu Cai
- Laboratory of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, China.,Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Can Gan
- Laboratory of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, China.,Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Chengwei Tang
- Laboratory of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, China.,Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Wu
- Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
| | - Jinhang Gao
- Laboratory of Gastroenterology and Hepatology, West China Hospital, Sichuan University, Chengdu, China.,Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, China
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12
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Peng XF, Huang SF, Chen LJ, Xu L, Ye WC. Targeting epigenetics and lncRNAs in liver disease: From mechanisms to therapeutics. Pharmacol Res 2021; 172:105846. [PMID: 34438063 DOI: 10.1016/j.phrs.2021.105846] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 12/19/2022]
Abstract
Early onset and progression of liver diseases can be driven by aberrant transcriptional regulation. Different transcriptional regulation processes, such as RNA/DNA methylation, histone modification, and ncRNA-mediated targeting, can regulate biological processes in healthy cells, as well also under various pathological conditions, especially liver disease. Numerous studies over the past decades have demonstrated that liver disease has a strong epigenetic component. Therefore, the epigenetic basis of liver disease has challenged our knowledge of epigenetics, and epigenetics field has undergone an important transformation: from a biological phenomenon to an emerging focus of disease research. Furthermore, inhibitors of different epigenetic regulators, such as m6A-related factors, are being explored as potential candidates for preventing and treating liver diseases. In the present review, we summarize and discuss the current knowledge of five distinct but interconnected and interdependent epigenetic processes in the context of hepatic diseases: RNA methylation, DNA methylation, histone methylation, miRNAs, and lncRNAs. Finally, we discuss the potential therapeutic implications and future challenges and ongoing research in the field. Our review also provides a perspective for identifying therapeutic targets and new hepatic biomarkers of liver disease, bringing precision research and disease therapy to the modern era of epigenetics.
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Affiliation(s)
- Xiao-Fei Peng
- Department of General Surgery, Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511518, Guangdong Province, China
| | - Shi-Feng Huang
- Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511518, Guangdong Province, China
| | - Ling-Juan Chen
- Department of Clinical Laboratory, Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511518, Guangdong Province, China
| | - Lingqing Xu
- Department of Clinical Laboratory, Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511518, Guangdong Province, China
| | - Wen-Chu Ye
- Qingyuan People's Hospital, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511518, Guangdong Province, China.
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13
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Early Steps of Hepatitis B Life Cycle: From Capsid Nuclear Import to cccDNA Formation. Viruses 2021; 13:v13050757. [PMID: 33925977 PMCID: PMC8145197 DOI: 10.3390/v13050757] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) remains a major public health concern, with more than 250 million chronically infected people who are at high risk of developing liver diseases, including cirrhosis and hepatocellular carcinoma. Although antiviral treatments efficiently control virus replication and improve liver function, they cannot cure HBV infection. Viral persistence is due to the maintenance of the viral circular episomal DNA, called covalently closed circular DNA (cccDNA), in the nuclei of infected cells. cccDNA not only resists antiviral therapies, but also escapes innate antiviral surveillance. This viral DNA intermediate plays a central role in HBV replication, as cccDNA is the template for the transcription of all viral RNAs, including pregenomic RNA (pgRNA), which in turn feeds the formation of cccDNA through a step of reverse transcription. The establishment and/or expression of cccDNA is thus a prime target for the eradication of HBV. In this review, we provide an update on the current knowledge on the initial steps of HBV infection, from the nuclear import of the nucleocapsid to the formation of the cccDNA.
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Suslov A, Meier MA, Ketterer S, Wang X, Wieland S, Heim MH. Transition to HBeAg-negative chronic hepatitis B virus infection is associated with reduced cccDNA transcriptional activity. J Hepatol 2021; 74:794-800. [PMID: 33188905 DOI: 10.1016/j.jhep.2020.11.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/30/2020] [Accepted: 11/05/2020] [Indexed: 01/06/2023]
Abstract
BACKGROUND & AIMS HBeAg seroconversion during the natural history of chronic hepatitis B (CHB) is associated with a strong drop in serum HBV DNA levels and a reduction of intrahepatic covalently closed circular DNA (cccDNA) content. Of particular interest is the transition to HBeAg-negative chronic infection (ENCI). ENCI, previously known as inactive carrier state, is characterized by very low or negative viremia and the absence of liver disease. The molecular mechanisms responsible for the transition to ENCI and for the control of viral replication in ENCI are still poorly understood. METHODS To identify which step(s) in the viral life cycle are controlled during the transition to ENCI, we quantified cccDNA, pre-genomic RNA (pgRNA), total HBV RNA and DNA replicative intermediates in 68 biopsies from patients in different phases of CHB. RESULTS HBeAg seroconversion is associated with a reduction of cccDNA amounts as well as transcriptional activity. Silencing of cccDNA is particularly pronounced in ENCI, where there was ~46 times less pgRNA per cccDNA compared to HBeAg-negative CHB. Furthermore, a subgroup of patients with HBeAg-negative CHB can be characterized by reduced replication efficiency downstream of pgRNA. CONCLUSIONS The reduction in serum viral load during the transition to ENCI seems to primarily result from strong inhibition of the transcriptional activity of cccDNA which can be maintained in the absence of liver disease. LAY SUMMARY During the natural course of chronic hepatitis B virus infections, the immune response can gain control of viral replication. Quantification of viral DNA and RNA in liver biopsies of patients in different stages of chronic hepatitis B allowed us to identify the steps in the viral life cycle that are affected during the transition from active to inactive disease. Therapeutic targeting of these steps might induce sustained inhibition of viral transcription.
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Affiliation(s)
- Aleksei Suslov
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland
| | - Marie-Anne Meier
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland; Division of Gastroenterology and Hepatology, University Center for Gastrointestinal and Liver Diseases, Basel, CH-4002, Switzerland
| | - Sylvia Ketterer
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland
| | - Xueya Wang
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland
| | - Stefan Wieland
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland.
| | - Markus Hermann Heim
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, CH-4031, Switzerland; Division of Gastroenterology and Hepatology, University Center for Gastrointestinal and Liver Diseases, Basel, CH-4002, Switzerland.
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15
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Function and Mechanism of Novel Histone Posttranslational Modifications in Health and Disease. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6635225. [PMID: 33763479 PMCID: PMC7952163 DOI: 10.1155/2021/6635225] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/15/2021] [Accepted: 02/23/2021] [Indexed: 02/06/2023]
Abstract
Histone posttranslational modifications (HPTMs) are crucial epigenetic mechanisms regulating various biological events. Different types of HPTMs characterize and shape functional chromatin states alone or in combination, and dedicated effector proteins selectively recognize these modifications for gene expression. The dysregulation of HPTM recognition events takes part in human diseases. With the application of mass spectrometry- (MS-) based proteomics, novel histone lysine acylation has been successively discovered, e.g., propionylation, butyrylation, 2-hydroxyisobutyrylation, β-hydroxybutyrylation, malonylation, succinylation, crotonylation, glutarylation, and lactylation. These nine types of modifications expand the repertoire of HPTMs and regulate chromatin remodeling, gene expression, cell cycle, and cellular metabolism. Recent researches show that HPTMs have a close connection with the pathogenesis of cancer, metabolic diseases, neuropsychiatric disorders, infertility, kidney diseases, and acquired immunodeficiency syndrome (AIDS). This review focuses on the chemical structure, sites, functions of these novel HPTMs, and underlying mechanism in gene expression, providing a glimpse into their complex regulation in health and disease.
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16
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D’Arienzo V, Magri A, Harris JM, Wing PAC, Ko C, Rubio CO, Revill PA, Protzer U, Balfe P, McKeating JA. A PCR assay to quantify patterns of HBV transcription. J Gen Virol 2021; 102:001373. [PMID: 31846416 PMCID: PMC7610515 DOI: 10.1099/jgv.0.001373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 11/27/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) is the prototype member of the family Hepadnaviridae and replicates via episomal copies of a covalently closed circular DNA (cccDNA) genome of approximately 3.2 kb. The chromatinization of this small viral genome, with overlapping open reading frames and regulatory elements, suggests an important role for epigenetic pathways to regulate HBV transcription. However, the host pathways that regulate HBV transcription and the temporal nature of promoter usage in infected cells are not well understood, in part due to the compact genome structure and overlapping open reading frames. To address this we developed a simple and cost-effective PCR assay to quantify the major viral RNAs and validated this technique using current state-of-art de novo HBV infection model systems. Our PCR method is three orders of magnitude more sensitive than Northern blot and requires relatively small amounts of starting material, making this an attractive tool for assessing HBV transcription.
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Affiliation(s)
- Valentina D’Arienzo
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
| | - Andrea Magri
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
| | - James M. Harris
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
| | - Peter A. C. Wing
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
| | - Chunkyu Ko
- Institute of Virology, Technische Universität, München/Helmholtz Zentrum München, Germany
| | - Claudia Orbegozo Rubio
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
| | - Peter A. Revill
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute of Infection and Immunity, Melbourne, Australia
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Australia
| | - Ulrike Protzer
- Institute of Virology, Technische Universität, München/Helmholtz Zentrum München, Germany
- German Center for Infection Research (DZIF), Munich partner site, Munich, Germany
| | - Peter Balfe
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, UK
| | - Jane A. McKeating
- Nuffield Department of Medicine, University of Oxford, Old Road Campus, Roosevelt Drive, Oxford, UK
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17
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El-Mesery M, El-Mowafy M, Youssef LF, El-Mesery A, Abed SY, Elgaml A. Serum Soluble Fibrinogen-Like Protein 2 Represents a Novel Biomarker for Differentiation Between Acute and Chronic Egyptian Hepatitis B Virus-Infected Patients. J Interferon Cytokine Res 2021; 41:52-59. [DOI: 10.1089/jir.2020.0118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Mohamed El-Mesery
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Mohammed El-Mowafy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Laila F. Youssef
- Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Ahmed El-Mesery
- Department of Tropical Medicine, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Sally Yussef Abed
- Department of Respiratory Care, College of Applied Medical Science in Jubail, Imam Abdulrahman Bin Faisal University, Jubail, Saudi Arabia
| | - Abdelaziz Elgaml
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
- Department of Microbiology and Immunology, Faculty of Pharmacy, Horus University, New Damietta, Egypt
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18
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D’Arienzo V, Ferguson J, Giraud G, Chapus F, Harris JM, Wing PAC, Claydon A, Begum S, Zhuang X, Balfe P, Testoni B, McKeating JA, Parish JL. The CCCTC-binding factor CTCF represses hepatitis B virus enhancer I and regulates viral transcription. Cell Microbiol 2021; 23:e13274. [PMID: 33006186 PMCID: PMC7116737 DOI: 10.1111/cmi.13274] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/09/2020] [Accepted: 09/29/2020] [Indexed: 12/17/2022]
Abstract
Hepatitis B virus (HBV) infection is of global importance with over 2 billion people exposed to the virus during their lifetime and at risk of progressive liver disease, cirrhosis and hepatocellular carcinoma. HBV is a member of the Hepadnaviridae family that replicates via episomal copies of a covalently closed circular DNA (cccDNA) genome. The chromatinization of this small viral genome, with overlapping open reading frames and regulatory elements, suggests an important role for epigenetic pathways to regulate viral transcription. The chromatin-organising transcriptional insulator protein, CCCTC-binding factor (CTCF), has been reported to regulate transcription in a diverse range of viruses. We identified two conserved CTCF binding sites in the HBV genome within enhancer I and chromatin immunoprecipitation (ChIP) analysis demonstrated an enrichment of CTCF binding to integrated or episomal copies of the viral genome. siRNA knock-down of CTCF results in a significant increase in pre-genomic RNA levels in de novo infected HepG2 cells and those supporting episomal HBV DNA replication. Furthermore, mutation of these sites in HBV DNA minicircles abrogated CTCF binding and increased pre-genomic RNA levels, providing evidence of a direct role for CTCF in repressing HBV transcription.
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Affiliation(s)
| | - Jack Ferguson
- institute of Cancer and Genomic sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Guillaume Giraud
- CRCL INSERM and Cancer Research Center of Lyon (CRCL), Lyon, France
| | - Fleur Chapus
- CRCL INSERM and Cancer Research Center of Lyon (CRCL), Lyon, France
| | - James M. Harris
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter A. C. Wing
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Adam Claydon
- institute of Cancer and Genomic sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Sophia Begum
- institute of Cancer and Genomic sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Xiaodong Zhuang
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter Balfe
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Barbara Testoni
- CRCL INSERM and Cancer Research Center of Lyon (CRCL), Lyon, France
| | | | - Joanna L. Parish
- institute of Cancer and Genomic sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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19
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Methionine metabolism in chronic liver diseases: an update on molecular mechanism and therapeutic implication. Signal Transduct Target Ther 2020; 5:280. [PMID: 33273451 PMCID: PMC7714782 DOI: 10.1038/s41392-020-00349-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/30/2020] [Accepted: 09/18/2020] [Indexed: 02/06/2023] Open
Abstract
As one of the bicyclic metabolic pathways of one-carbon metabolism, methionine metabolism is the pivot linking the folate cycle to the transsulfuration pathway. In addition to being a precursor for glutathione synthesis, and the principal methyl donor for nucleic acid, phospholipid, histone, biogenic amine, and protein methylation, methionine metabolites can participate in polyamine synthesis. Methionine metabolism disorder can aggravate the damage in the pathological state of a disease. In the occurrence and development of chronic liver diseases (CLDs), changes in various components involved in methionine metabolism can affect the pathological state through various mechanisms. A methionine-deficient diet is commonly used for building CLD models. The conversion of key enzymes of methionine metabolism methionine adenosyltransferase (MAT) 1 A and MAT2A/MAT2B is closely related to fibrosis and hepatocellular carcinoma. In vivo and in vitro experiments have shown that by intervening related enzymes or downstream metabolites to interfere with methionine metabolism, the liver injuries could be reduced. Recently, methionine supplementation has gradually attracted the attention of many clinical researchers. Most researchers agree that adequate methionine supplementation can help reduce liver damage. Retrospective analysis of recently conducted relevant studies is of profound significance. This paper reviews the latest achievements related to methionine metabolism and CLD, from molecular mechanisms to clinical research, and provides some insights into the future direction of basic and clinical research.
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20
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Lebossé F, Inchauspé A, Locatelli M, Miaglia C, Diederichs A, Fresquet J, Chapus F, Hamed K, Testoni B, Zoulim F. Quantification and epigenetic evaluation of the residual pool of hepatitis B covalently closed circular DNA in long-term nucleoside analogue-treated patients. Sci Rep 2020; 10:21097. [PMID: 33273565 PMCID: PMC7712874 DOI: 10.1038/s41598-020-78001-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) covalently closed circular (ccc)DNA is the key genomic form responsible for viral persistence and virological relapse after treatment withdrawal. The assessment of residual intrahepatic cccDNA levels and activity after long-term nucleos(t)ide analogues therapy still represents a technical challenge. Quantitative (q)PCR, rolling circle amplification (RCA) and droplet digital (dd)PCR assays were used to quantify residual intrahepatic cccDNA in liver biopsies from 56 chronically HBV infected patients after 3 to 5 years of telbivudine treatment. Activity of residual cccDNA was evaluated by quantifying 3.5 kB HBV RNA (preC/pgRNA) and by assessing cccDNA-associated histone tails post-transcriptional modifications (PTMs) by micro-chromatin immunoprecipitation. Long-term telbivudine treatment resulted in serum HBV DNA suppression, with most of the patients reaching undetectable levels. Despite 38 out of 56 patients had undetectable cccDNA when assessed by qPCR, RCA and ddPCR assays detected cccDNA in all-but-one negative samples. Low preC/pgRNA level in telbivudine-treated samples was associated with enrichment for cccDNA histone PTMs related to repressed transcription. No difference in cccDNA levels was found according to serum viral markers evolution. This panel of cccDNA evaluation techniques should provide an added value for the new proof-of-concept clinical trials aiming at a functional cure of chronic hepatitis B.
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Affiliation(s)
- Fanny Lebossé
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France.,Department of Hepatology, Croix Rousse Hospital, Hospices Civils de Lyon, Lyon, France
| | - Aurore Inchauspé
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France
| | - Maëlle Locatelli
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France
| | - Clothilde Miaglia
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France.,Department of Hepatology, Croix Rousse Hospital, Hospices Civils de Lyon, Lyon, France
| | - Audrey Diederichs
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France
| | - Judith Fresquet
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France
| | - Fleur Chapus
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France.,University of Lyon, UMR_S1052, CRCL, Lyon, France
| | - Kamal Hamed
- Novartis Pharmaceuticals Corporation, East Hanover, NJ, USA
| | - Barbara Testoni
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France. .,University of Lyon, UMR_S1052, CRCL, Lyon, France.
| | - Fabien Zoulim
- INSERM U1052-Cancer Research Center of Lyon (CRCL), Lyon, France. .,University of Lyon, UMR_S1052, CRCL, Lyon, France. .,Department of Hepatology, Croix Rousse Hospital, Hospices Civils de Lyon, Lyon, France.
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21
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Dandri M, Petersen J. cccDNA Maintenance in Chronic Hepatitis B - Targeting the Matrix of Viral Replication. Infect Drug Resist 2020; 13:3873-3886. [PMID: 33149632 PMCID: PMC7605611 DOI: 10.2147/idr.s240472] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022] Open
Abstract
Chronic hepatitis B is a numerically important cause of cirrhosis and hepatocellular carcinoma, despite an effective prophylactic vaccine and well-tolerated and effective oral antivirals. Both the incapacity of the immune system to clear hepatitis B virus (HBV) infection and the unique replication strategies adopted by HBV are considered key determinants of HBV chronicity. In this regard, the formation of the HBV DNA minichromosome, the covalently closed circular DNA (cccDNA), in the nucleus of infected hepatocytes, is essential not only for the production of all viral proteins but also for HBV persistence even after long-term antiviral therapy. Licensed polymerase inhibitors target the HBV reverse transcriptase activity, control the disease with long-term therapy but fail to eliminate the cccDNA. Consequently, the production of viral RNAs and proteins, including the hepatitis B surface antigen (HBsAg), is not abolished. Novel therapeutic efforts that are in the pipeline for early clinical trials explore novel targets and molecules. Such therapeutic efforts focus on achieving a functional cure, which is defined by the loss of HBsAg and undetectable HBV DNA levels in serum. Since a true cure of HBV infection requires the elimination of the cccDNA from infected cells, comprehension of the mechanisms implicated in cccDNA biogenesis, regulation and stability appears necessary to achieve HBV eradication. In this review, we will summarize the state of knowledge on cccDNA metabolism, focusing on insights suggesting potential weak points of the cccDNA that may be key for the development of therapeutic approaches and design of clinical trials aiming at lowering cccDNA loads and activity.
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Affiliation(s)
- Maura Dandri
- Department of Internal Medicine, University Medical Center Hamburg - Eppendorf, Hamburg, Germany.,German Center for Infection Research (DZIF), Hamburg-Luebeck-Borstel-Riems Site, Germany
| | - Joerg Petersen
- Institute for Interdisciplinary Medicine, Asklepios Klinik St Georg, University of Hamburg, Hamburg, Germany
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22
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Taha TY, Anirudhan V, Limothai U, Loeb DD, Petukhov PA, McLachlan A. Modulation of hepatitis B virus pregenomic RNA stability and splicing by histone deacetylase 5 enhances viral biosynthesis. PLoS Pathog 2020; 16:e1008802. [PMID: 32822428 PMCID: PMC7467325 DOI: 10.1371/journal.ppat.1008802] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 09/02/2020] [Accepted: 07/13/2020] [Indexed: 12/15/2022] Open
Abstract
Hepatitis B virus (HBV) is a worldwide health problem without curative treatments. Investigation of the regulation of HBV biosynthesis by class I and II histone deacetylases (HDACs) demonstrated that catalytically active HDAC5 upregulates HBV biosynthesis. HDAC5 expression increased both the stability and splicing of the HBV 3.5 kb RNA without altering the translational efficiency of the viral pregenomic or spliced 2.2 kb RNAs. Together, these observations point to a broader role of HDAC5 in regulating RNA splicing and transcript stability while specifically identifying a potentially novel approach toward antiviral HBV therapeutic development. This study demonstrates that HDAC5 deacetylation of host cellular factor(s) results in increased HBV biosynthesis by enhancing viral transcript stability and splicing via direct or indirect binding of host factors to viral intron sequences. This represents the first demonstration of this type of post-transcriptional regulation in the liver and is similar to observations seen for cellular transcripts in neural and cardiac cell types. These observations suggest a more general phenomenon which could represent an additional post-transcriptional code governing the regulation of RNA:protein interactions and hence RNA metabolism. Therefore, covalent modifications of RNA binding proteins may modulate post-transcriptional gene expression in an analogous manner to the known histone code that controls gene transcription. Although this analysis primarily relates to the mechanism(s) by which HDAC5 governs HBV RNA metabolism, it does have significant therapeutic implications. The inhibition of HDAC5 in combination with current nucleos(t)ide analog drugs targeting the viral reverse transcriptase/DNA polymerase might aid in the treatment and possible resolution of chronic infections by targeting both host and viral factors.
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Affiliation(s)
- Taha Y. Taha
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Varada Anirudhan
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Umaporn Limothai
- Center of Excellence in Hepatitis and Liver Cancer, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Daniel D. Loeb
- McArdle Laboratory for Cancer Research, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Pavel A. Petukhov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail: (PAP); (AM)
| | - Alan McLachlan
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail: (PAP); (AM)
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23
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Dandri M. Epigenetic modulation in chronic hepatitis B virus infection. Semin Immunopathol 2020; 42:173-185. [PMID: 32185454 PMCID: PMC7174266 DOI: 10.1007/s00281-020-00780-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/08/2020] [Indexed: 02/06/2023]
Abstract
The human hepatitis B virus (HBV) is a small-enveloped DNA virus causing acute and chronic hepatitis. Despite the existence of an effective prophylactic vaccine and the strong capacity of approved antiviral drugs to suppress viral replication, chronic HBV infection (CHB) continues to be a major health burden worldwide. Both the inability of the immune system to resolve CHB and the unique replication strategy employed by HBV, which forms a stable viral covalently closed circular DNA (cccDNA) minichromosome in the hepatocyte nucleus, enable infection persistence. Knowledge of the complex network of interactions that HBV engages with its host is still limited but accumulating evidence indicates that epigenetic modifications occurring both on the cccDNA and on the host genome in the course of infection are essential to modulate viral activity and likely contribute to pathogenesis and cancer development. Thus, a deeper understanding of epigenetic regulatory processes may open new venues to control and eventually cure CHB. This review summarizes major findings in HBV epigenetic research, focusing on the epigenetic mechanisms regulating cccDNA activity and the modifications determined in infected host cells and tumor liver tissues.
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Affiliation(s)
- Maura Dandri
- I. Department of Internal Medicine, Center for Internal Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany. .,German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel-Riems Site, Hamburg, Germany.
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Mohd-Ismail NK, Lim Z, Gunaratne J, Tan YJ. Mapping the Interactions of HBV cccDNA with Host Factors. Int J Mol Sci 2019; 20:ijms20174276. [PMID: 31480501 PMCID: PMC6747236 DOI: 10.3390/ijms20174276] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 08/26/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a major health problem affecting about 300 million people globally. Although successful administration of a prophylactic vaccine has reduced new infections, a cure for chronic hepatitis B (CHB) is still unavailable. Current anti-HBV therapies slow down disease progression but are not curative as they cannot eliminate or permanently silence HBV covalently closed circular DNA (cccDNA). The cccDNA minichromosome persists in the nuclei of infected hepatocytes where it forms the template for all viral transcription. Interactions between host factors and cccDNA are crucial for its formation, stability, and transcriptional activity. Here, we summarize the reported interactions between HBV cccDNA and various host factors and their implications on HBV replication. While the virus hijacks certain cellular processes to complete its life cycle, there are also host factors that restrict HBV infection. Therefore, we review both positive and negative regulation of HBV cccDNA by host factors and the use of small molecule drugs or sequence-specific nucleases to target these interactions or cccDNA directly. We also discuss several reporter-based surrogate systems that mimic cccDNA biology which can be used for drug library screening of cccDNA-targeting compounds as well as identification of cccDNA-related targets.
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Affiliation(s)
- Nur K Mohd-Ismail
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore 117545, Singapore
| | - Zijie Lim
- Department of Medicine, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore 119228, Singapore
| | - Jayantha Gunaratne
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore
| | - Yee-Joo Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore 117545, Singapore.
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Singapore 138673, Singapore.
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