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Sun S, Zhong B, Zeng X, Li J, Chen Q. Transcription factor E4F1 as a regulator of cell life and disease progression. SCIENCE ADVANCES 2023; 9:eadh1991. [PMID: 37774036 PMCID: PMC10541018 DOI: 10.1126/sciadv.adh1991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 08/31/2023] [Indexed: 10/01/2023]
Abstract
E4F transcription factor 1 (E4F1), a member of the GLI-Kruppel family of zinc finger proteins, is now widely recognized as a transcription factor. It plays a critical role in regulating various cell processes, including cell growth, proliferation, differentiation, apoptosis and necrosis, DNA damage response, and cell metabolism. These processes involve intricate molecular regulatory networks, making E4F1 an important mediator in cell biology. Moreover, E4F1 has also been implicated in the pathogenesis of a range of human diseases. In this review, we provide an overview of the major advances in E4F1 research, from its first report to the present, including studies on its protein domains, molecular mechanisms of transcriptional regulation and biological functions, and implications for human diseases. We also address unresolved questions and potential research directions in this field. This review provides insights into the essential roles of E4F1 in human health and disease and may pave the way for facilitating E4F1 from basic research to clinical applications.
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Affiliation(s)
- Silu Sun
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Bing Zhong
- Upper Airways Research Laboratory, Department of Otolaryngology–Head and Neck Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Xin Zeng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
| | - Qianming Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
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2
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Villanueva RA, Loyola A. Pre- and Post-Transcriptional Control of HBV Gene Expression: The Road Traveled towards the New Paradigm of HBx, Its Isoforms, and Their Diverse Functions. Biomedicines 2023; 11:1674. [PMID: 37371770 DOI: 10.3390/biomedicines11061674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/04/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Hepatitis B virus (HBV) is an enveloped DNA human virus belonging to the Hepadnaviridae family. Perhaps its main distinguishable characteristic is the replication of its genome through a reverse transcription process. The HBV circular genome encodes only four overlapping reading frames, encoding for the main canonical proteins named core, P, surface, and X (or HBx protein). However, pre- and post-transcriptional gene regulation diversifies the full HBV proteome into diverse isoform proteins. In line with this, hepatitis B virus X protein (HBx) is a viral multifunctional and regulatory protein of 16.5 kDa, whose canonical reading frame presents two phylogenetically conserved internal in-frame translational initiation codons, and which results as well in the expression of two divergent N-terminal smaller isoforms of 8.6 and 5.8 kDa, during translation. The canonical HBx, as well as the smaller isoform proteins, displays different roles during viral replication and subcellular localizations. In this article, we reviewed the different mechanisms of pre- and post-transcriptional regulation of protein expression that take place during viral replication. We also investigated all the past and recent evidence about HBV HBx gene regulation and its divergent N-terminal isoform proteins. Evidence has been collected for over 30 years. The accumulated evidence simply strengthens the concept of a new paradigm of the canonical HBx, and its smaller divergent N-terminal isoform proteins, not only during viral replication, but also throughout cell pathogenesis.
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Affiliation(s)
| | - Alejandra Loyola
- Centro Ciencia & Vida, Fundación Ciencia & Vida, Santiago 8580702, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago 7510602, Chile
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3
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Canonical and Divergent N-Terminal HBx Isoform Proteins Unveiled: Characteristics and Roles during HBV Replication. Biomedicines 2021; 9:biomedicines9111701. [PMID: 34829930 PMCID: PMC8616016 DOI: 10.3390/biomedicines9111701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/11/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022] Open
Abstract
Hepatitis B virus (HBV) X protein (HBx) is a viral regulatory and multifunctional protein. It is well-known that the canonical HBx reading frame bears two phylogenetically conserved internal in-frame translational initiation codons at Met2 and Met3, thus possibly generating divergent N-terminal smaller isoforms during translation. Here, we demonstrate that the three distinct HBx isoforms are generated from the ectopically expressed HBV HBx gene, named XF (full-length), XM (medium-length), and XS (short-length); they display different subcellular localizations when expressed individually in cultured hepatoma cells. Particularly, the smallest HBx isoform, XS, displayed a predominantly cytoplasmic localization. To study HBx proteins during viral replication, we performed site-directed mutagenesis to target the individual or combinatorial expression of the HBx isoforms within the HBV viral backbone (full viral genome). Our results indicate that of all HBx isoforms, only the smallest HBx isoform, XS, can restore WT levels of HBV replication, and bind to the viral mini chromosome, thereby establishing an active chromatin state, highlighting its crucial activities during HBV replication. Intriguingly, we found that sequences of HBV HBx genotype H are devoid of the conserved Met3 position, and therefore HBV genotype H infection is naturally silent for the expression of the HBx XS isoform. Finally, we found that the HBx XM (medium-length) isoform shares significant sequence similarity with the N-terminus domain of the COMMD8 protein, a member of the copper metabolism MURR1 domain-containing (COMMD) protein family. This novel finding might facilitate studies on the phylogenetic origin of the HBV X protein. The identification and functional characterization of its isoforms will shift the paradigm by changing the concept of HBx from being a unique, canonical, and multifunctional protein toward the occurrence of different HBx isoforms, carrying out different overlapping functions at different subcellular localizations during HBV genome replication. Significantly, our current work unveils new crucial HBV targets to study for potential antiviral research, and human virus pathogenesis.
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Van Damme E, Vanhove J, Severyn B, Verschueren L, Pauwels F. The Hepatitis B Virus Interactome: A Comprehensive Overview. Front Microbiol 2021; 12:724877. [PMID: 34603251 PMCID: PMC8482013 DOI: 10.3389/fmicb.2021.724877] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/17/2021] [Indexed: 12/19/2022] Open
Abstract
Despite the availability of a prophylactic vaccine, chronic hepatitis B (CHB) caused by the hepatitis B virus (HBV) is a major health problem affecting an estimated 292 million people globally. Current therapeutic goals are to achieve functional cure characterized by HBsAg seroclearance and the absence of HBV-DNA after treatment cessation. However, at present, functional cure is thought to be complicated due to the presence of covalently closed circular DNA (cccDNA) and integrated HBV-DNA. Even if the episomal cccDNA is silenced or eliminated, it remains unclear how important the high level of HBsAg that is expressed from integrated HBV DNA is for the pathology. To identify therapies that could bring about high rates of functional cure, in-depth knowledge of the virus' biology is imperative to pinpoint mechanisms for novel therapeutic targets. The viral proteins and the episomal cccDNA are considered integral for the control and maintenance of the HBV life cycle and through direct interaction with the host proteome they help create the most optimal environment for the virus whilst avoiding immune detection. New HBV-host protein interactions are continuously being identified. Unfortunately, a compendium of the most recent information is lacking and an interactome is unavailable. This article provides a comprehensive review of the virus-host relationship from viral entry to release, as well as an interactome of cccDNA, HBc, and HBx.
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Affiliation(s)
- Ellen Van Damme
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
| | - Jolien Vanhove
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium.,Early Discovery Biology, Charles River Laboratories, Beerse, Belgium
| | - Bryan Severyn
- Janssen Research & Development, Janssen Pharmaceutical Companies, Springhouse, PA, United States
| | - Lore Verschueren
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
| | - Frederik Pauwels
- Janssen Research & Development, Janssen Pharmaceutical Companies, Beerse, Belgium
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5
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Kong F, Zhang F, Liu X, Qin S, Yang X, Kong D, Pan X, You H, Zheng K, Tang R. Calcium signaling in hepatitis B virus infection and its potential as a therapeutic target. Cell Commun Signal 2021; 19:82. [PMID: 34362380 PMCID: PMC8349099 DOI: 10.1186/s12964-021-00762-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/25/2021] [Indexed: 12/15/2022] Open
Abstract
As a ubiquitous second messenger, calcium (Ca2+) can interact with numerous cellular proteins to regulate multiple physiological processes and participate in a variety of diseases, including hepatitis B virus (HBV) infection, which is a major cause of hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. In recent years, several studies have demonstrated that depends on the distinct Ca2+ channels on the plasma membrane, endoplasmic reticulum, as well as mitochondria, HBV can elevate cytosolic Ca2+ levels. Moreover, within HBV-infected cells, the activation of intracellular Ca2+ signaling contributes to viral replication via multiple molecular mechanisms. Besides, the available evidence indicates that targeting Ca2+ signaling by suitable pharmaceuticals is a potent approach for the treatment of HBV infection. In the present review, we summarized the molecular mechanisms related to the elevation of Ca2+ signaling induced by HBV to modulate viral propagation and the recent advances in Ca2+ signaling as a potential therapeutic target for HBV infection. Video Abstract.
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Affiliation(s)
- Fanyun Kong
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Fulong Zhang
- Imaging Department, The Second Affiliated Hospital of Shandong First Medical University, Taian, Shandong China
| | - Xiangye Liu
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Suping Qin
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Xiaoying Yang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Delong Kong
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Xiucheng Pan
- Department of Infectious Diseases, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu China
| | - Hongjuan You
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
| | - Kuiyang Zheng
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
- National Demonstration Center for Experimental Basic Medical Sciences Education, Xuzhou Medical University, Xuzhou, Jiangsu China
| | - Renxian Tang
- Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, 221004 Jiangsu China
- National Demonstration Center for Experimental Basic Medical Sciences Education, Xuzhou Medical University, Xuzhou, Jiangsu China
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6
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Panda S, Behera S, Alam MF, Syed GH. Endoplasmic reticulum & mitochondrial calcium homeostasis: The interplay with viruses. Mitochondrion 2021; 58:227-242. [PMID: 33775873 DOI: 10.1016/j.mito.2021.03.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 03/08/2021] [Accepted: 03/22/2021] [Indexed: 02/08/2023]
Abstract
Calcium ions (Ca2+) act as secondary messengers in a plethora of cellular processes and play crucial role in cellular organelle function and homeostasis. The average resting concentration of Ca2+ is nearly 100 nM and in certain cells it can reach up to 1 µM. The high range of Ca2+ concentration across the plasma membrane and intracellular Ca2+ stores demands a well-coordinated maintenance of free Ca2+ via influx, efflux, buffering and storage. Endoplasmic Reticulum (ER) and Mitochondria depend on Ca2+ for their function and also serve as major players in intracellular Ca2+ homeostasis. The ER-mitochondria interplay helps in orchestrating cellular calcium homeostasis to avoid any detrimental effect resulting from Ca2+ overload or depletion. Since Ca2+ plays a central role in many biological processes it is an essential component of the virus-host interactions. The large gradient across membranes enable the viruses to easily modulate this buffered environment to meet their needs. Viruses exploit Ca2+ signaling to establish productive infection and evade the host immune defense. In this review we will detail the interplay between the viruses and cellular & ER-mitochondrial calcium signaling and the significance of these events on viral life cycle and disease pathogenesis.
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Affiliation(s)
- Swagatika Panda
- Institute of Life Sciences, Bhubaneswar, Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneswar, India
| | - Suchismita Behera
- Institute of Life Sciences, Bhubaneswar, Clinical Proteomics Laboratory, Institute of Life Sciences, Bhubaneswar, India
| | - Mohd Faraz Alam
- Institute of Life Sciences, Bhubaneswar, Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneswar, India
| | - Gulam Hussain Syed
- Institute of Life Sciences, Bhubaneswar, Virus-Host Interaction Lab, Institute of Life Sciences, Bhubaneswar, India.
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7
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Chen Y, Yang W, Chen Q, Liu Q, Liu J, Zhang Y, Li B, Li D, Nan J, Li X, Wu H, Xiang X, Peng Y, Wang J, Su S, Wang Z. Prediction of hepatocellular carcinoma risk in patients with chronic liver disease from dynamic modular networks. J Transl Med 2021; 19:122. [PMID: 33757544 PMCID: PMC7989040 DOI: 10.1186/s12967-021-02791-9] [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: 11/26/2020] [Accepted: 03/16/2021] [Indexed: 12/17/2022] Open
Abstract
Background Discovering potential predictive risks in the super precarcinomatous phase of hepatocellular carcinoma (HCC) without any clinical manifestations is impossible under normal paradigm but critical to control this complex disease. Methods In this study, we utilized a proposed sequential allosteric modules (AMs)-based approach and quantitatively calculated the topological structural variations of these AMs. Results We found the total of 13 oncogenic allosteric modules (OAMs) among chronic hepatitis B (CHB), cirrhosis and HCC network used SimiNEF. We obtained the 11 highly correlated gene pairs involving 15 genes (r > 0.8, P < 0.001) from the 12 OAMs (the out-of-bag (OOB) classification error rate < 0.5) partial consistent with those in independent clinical microarray data, then a three-gene set (cyp1a2-cyp2c19-il6) was optimized to distinguish HCC from non-tumor liver tissues using random forests with an average area under the curve (AUC) of 0.973. Furthermore, we found significant inhibitory effect on the tumor growth of Bel-7402, Hep 3B and Huh7 cell lines in zebrafish treated with the compounds affected those three genes. Conclusions These findings indicated that the sequential AMs-based approach could detect HCC risk in the patients with chronic liver disease and might be applied to any time-dependent risk of cancer. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-021-02791-9.
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Affiliation(s)
- Yinying Chen
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, No. 5 Beixian Ge, Xicheng District, Beijing, 100053, China.,Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China.,Postdoctoral Research Station, China Academy of Chinese Medical Sciences, Beijing, China
| | - Wei Yang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China
| | - Qilong Chen
- Research Center for Traditional Chinese Medicine Complexity System, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, 201203, China
| | - Qiong Liu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China
| | - Jun Liu
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China
| | - Yingying Zhang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China
| | - Bing Li
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China
| | - Dongfeng Li
- School of Mathematical Sciences, Peking University, Beijing, China
| | - Jingyi Nan
- Shandong Danhong Pharmaceutical Co. Ltd., Heze, China
| | - Xiaodong Li
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Huikun Wu
- Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, China
| | - Xinghua Xiang
- School of Mathematics and Computational Science, Hunan University of Science and Technology, Xiangtan, China
| | - Yehui Peng
- School of Mathematics and Computational Science, Hunan University of Science and Technology, Xiangtan, China
| | - Jie Wang
- Guang'anmen Hospital, China Academy of Chinese Medical Sciences, No. 5 Beixian Ge, Xicheng District, Beijing, 100053, China.
| | - Shibing Su
- Research Center for Traditional Chinese Medicine Complexity System, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, 201203, China.
| | - Zhong Wang
- Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, Dongzhimen, Beijing, 100700, China.
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8
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Kim SA, Cho EJ, Lee S, Cho YY, Kim B, Yoon JH, Park T. Changes in serum fibronectin levels predict tumor recurrence in patients with early hepatocellular carcinoma after curative treatment. Sci Rep 2020; 10:21313. [PMID: 33277619 PMCID: PMC7719187 DOI: 10.1038/s41598-020-78440-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023] Open
Abstract
Fibronectin, a matrix glycoprotein aberrantly expressed in various tumor cells, is a known candidate biomarker for the early diagnosis of hepatocellular carcinoma (HCC). In this study, we investigated whether serum fibronectin levels could predict tumor recurrence in patients with early-stage HCC after curative treatment. A total of 83 patients who showed complete response after initial curative treatment were included. The levels of serum fibronectin at baseline and 4–6 weeks after initial treatment were analyzed with regard to their associations with recurrence. Multivariate logistic regression analyses were performed to construct a prognostic nomogram. Baseline fibronectin levels were not significantly correlated with tumor size, number, stage, and serum α-fetoprotein levels. However, decrease in serum fibronectin levels after treatment was significantly associated with reduced HCC recurrence in multivariate logistic regression (odds ratio, 0.009; p < 0.001). Furthermore, a nomogram consisting of gender and changes in serum fibronectin showed a good discriminatory capability for the prediction of HCC recurrence with an area under the receiver-operating curve of 0.87. In conclusion, changes in serum fibronectin levels may be a surrogate indicator for assessment of treatment response in patients with early HCC after curative treatment.
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Affiliation(s)
- Sun Ah Kim
- The Research Institute of Basic Sciences, Seoul National University, Seoul, Korea
| | - Eun Ju Cho
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Sungyoung Lee
- Center for Precision Medicine, Seoul National University Hospital, Seoul, Korea
| | - Young Youn Cho
- Department of Internal Medicine, Chung-Ang University Hospital, Seoul, Korea
| | - Boram Kim
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul, Korea
| | - Jung-Hwan Yoon
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Taesung Park
- Department of Statistics, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
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9
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Li H, Yan L, Shi Y, Lv D, Shang J, Bai L, Tang H. Hepatitis B Virus Infection: Overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1179:1-16. [PMID: 31741331 DOI: 10.1007/978-981-13-9151-4_1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hepatitis B virus (HBV) is a DNA virus, belonging to the Hepadnaviridae family. It is a partially double-stranded DNA virus with a small viral genome (3.2 kb). Chronic HBV infection remains a global public health problem. If left untreated, chronic HBV infection can progress to end-stage liver disease, such as liver cirrhosis and hepatocellular carcinoma (HCC). In recent years, tremendous advances in the field of HBV basic and clinical research have been achieved, ranging from the HBV biological characteristics, immunopathogenesis, and animal models to the development of new therapeutic strategies and new drugs against HBV. In this overview, we begin with a brief history of HBV discovery and treatment milestones. We then briefly summarize the HBV research advances, which will be detailed in the following chapters.
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Affiliation(s)
- Hong Li
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Libo Yan
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ying Shi
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Duoduo Lv
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jin Shang
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lang Bai
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hong Tang
- Center of Infectious Diseases, Division of Infectious Diseases, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
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10
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Ross EC, Olivera GC, Barragan A. Dysregulation of focal adhesion kinase upon
Toxoplasma gondii
infection facilitates parasite translocation across polarised primary brain endothelial cell monolayers. Cell Microbiol 2019; 21:e13048. [DOI: 10.1111/cmi.13048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Emily C. Ross
- Department of Molecular Biosciences, The Wenner‐Gren InstituteStockholm University Stockholm Sweden
| | - Gabriela C. Olivera
- Department of Molecular Biosciences, The Wenner‐Gren InstituteStockholm University Stockholm Sweden
| | - Antonio Barragan
- Department of Molecular Biosciences, The Wenner‐Gren InstituteStockholm University Stockholm Sweden
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11
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Bergmann S, Elbahesh H. Targeting the proviral host kinase, FAK, limits influenza a virus pathogenesis and NFkB-regulated pro-inflammatory responses. Virology 2019; 534:54-63. [PMID: 31176924 DOI: 10.1016/j.virol.2019.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/29/2019] [Accepted: 05/30/2019] [Indexed: 01/08/2023]
Abstract
Influenza A virus (IAV) infections result in ∼500,000 global deaths annually. Host kinases link multiple signaling pathways at various stages of infection and are attractive therapeutic target. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, regulates several cellular processes including NFkB and antiviral responses. We investigated how FAK kinase activity regulates IAV pathogenesis. Using a severe infection model, we infected IAV-susceptible DBA/2 J mice with a lethal dose of H1N1 IAV. We observed reduced viral load and pro-inflammatory cytokines, delayed mortality, and increased survival in FAK inhibitor (Y15) treated mice. In vitro IAV-induced NFkB-promoter activity was reduced by Y15 or a dominant negative kinase-dead FAK mutant (FAK-KD) independently of the viral immune modulator, NS1. Finally, we observed reduced IAV-induced nuclear localization of NFkB in FAK-KD expressing cells. Our data suggest a novel mechanism where IAV hijacks FAK to promote viral replication and limit its ability to contribute to innate immune responses.
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Affiliation(s)
- Silke Bergmann
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Husni Elbahesh
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, 38163, USA.
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12
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Tian JH, Liu WD, Zhang ZY, Tang LH, Li D, Tian ZJ, Lin SW, Li YJ. Influence of miR-520e-mediated MAPK signalling pathway on HBV replication and regulation of hepatocellular carcinoma cells via targeting EphA2. J Viral Hepat 2019; 26:496-505. [PMID: 30521133 DOI: 10.1111/jvh.13048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/09/2018] [Accepted: 11/01/2018] [Indexed: 12/12/2022]
Abstract
We determined the role of miR-520e in the replication of hepatitis B virus (HBV) and the growth of hepatocellular carcinoma (HCC) cells. MiR-520e and EPH receptor A2 (EphA2) in HBV-positive HCC tissues and cells were detected, and we studied the impact of miR-520e and the EphA2 receptor in cellular and murine HBV replication models. We find that MiR-520e was upregulated and EphA2 was downregulated in HBV-positive HCC tissues and cells. MiR-520e was decreased in Huh7-X and HepG2-X cells in which HBx was stably expressed, but was dose-dependently elevated after interfering with HBx. Additionally, miR-520e mimic and si-EphA2 groups were reduced in association with increases in HBV DNA content, HBsAg and HBeAg levels, cell proliferation and were enhanced in the expressions of EphA2, p-p38MAPK/p38MAPK, phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2)/ERK1/2 and cell apoptosis. Furthermore, si-EphA2 reversed the promotion effect of miR-520e inhibitor on HBV replication and tumour cell growth. Upregulating miR-520e in rAAV8-1.3HBV-infected mouse resulted in reduced EphA2 in liver tissues and HBV DNA content in serum. We find that MiR-520e was decreased in HBV-positive HCC, while overexpression of miR-520e blocked p38MAPK and ERK1/2 signalling pathways by an inhibitory effect on EphA2 and ultimately reduced HBV replication and inhibited tumour cell growth. These data indicate a role for miR-520e in the regulation of HBV replication.
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Affiliation(s)
- Jing-Hui Tian
- Central Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Ji'nan, China.,School of Public Health, Taishan Medical University, Taian, China
| | - Wen-Dong Liu
- Department of Blood Transfusion, Affiliated Hospital of Weifang Medical University, Weifang, China
| | - Zhi-Yong Zhang
- Clinical Laboratory, Dezhou People's Hospital, Dezhou, China
| | - Li-Hua Tang
- Department of Blood Transfusion, Tai'an City Central Hospital, Tai'an, China
| | - Dong Li
- School of Public Health, Taishan Medical University, Taian, China
| | - Zhao-Ju Tian
- School of Public Health, Taishan Medical University, Taian, China
| | - Shao-Wei Lin
- School of Public Health, Taishan Medical University, Taian, China
| | - Ying-Jie Li
- Department of Health Examination, Qilu Hospital, Shandong University, Jinan, China
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13
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Meineke R, Rimmelzwaan GF, Elbahesh H. Influenza Virus Infections and Cellular Kinases. Viruses 2019; 11:E171. [PMID: 30791550 PMCID: PMC6410056 DOI: 10.3390/v11020171] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/13/2019] [Accepted: 02/14/2019] [Indexed: 12/24/2022] Open
Abstract
Influenza A viruses (IAVs) are a major cause of respiratory illness and are responsible for yearly epidemics associated with more than 500,000 annual deaths globally. Novel IAVs may cause pandemic outbreaks and zoonotic infections with, for example, highly pathogenic avian influenza virus (HPAIV) of the H5N1 and H7N9 subtypes, which pose a threat to public health. Treatment options are limited and emergence of strains resistant to antiviral drugs jeopardize this even further. Like all viruses, IAVs depend on host factors for every step of the virus replication cycle. Host kinases link multiple signaling pathways in respond to a myriad of stimuli, including viral infections. Their regulation of multiple response networks has justified actively targeting cellular kinases for anti-cancer therapies and immune modulators for decades. There is a growing volume of research highlighting the significant role of cellular kinases in regulating IAV infections. Their functional role is illustrated by the required phosphorylation of several IAV proteins necessary for replication and/or evasion/suppression of the innate immune response. Identified in the majority of host factor screens, functional studies further support the important role of kinases and their potential as host restriction factors. PKC, ERK, PI3K and FAK, to name a few, are kinases that regulate viral entry and replication. Additionally, kinases such as IKK, JNK and p38 MAPK are essential in mediating viral sensor signaling cascades that regulate expression of antiviral chemokines and cytokines. The feasibility of targeting kinases is steadily moving from bench to clinic and already-approved cancer drugs could potentially be repurposed for treatments of severe IAV infections. In this review, we will focus on the contribution of cellular kinases to IAV infections and their value as potential therapeutic targets.
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Affiliation(s)
- Robert Meineke
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine (TiHo), Bünteweg 17, 30559 Hannover, Germany.
| | - Guus F Rimmelzwaan
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine (TiHo), Bünteweg 17, 30559 Hannover, Germany.
| | - Husni Elbahesh
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine (TiHo), Bünteweg 17, 30559 Hannover, Germany.
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14
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von Olshausen G, Quasdorff M, Bester R, Arzberger S, Ko C, van de Klundert M, Zhang K, Odenthal M, Ringelhan M, Niessen CM, Protzer U. Hepatitis B virus promotes β-catenin-signalling and disassembly of adherens junctions in a Src kinase dependent fashion. Oncotarget 2018; 9:33947-33960. [PMID: 30338037 PMCID: PMC6188061 DOI: 10.18632/oncotarget.26103] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/27/2018] [Indexed: 12/31/2022] Open
Abstract
Hepatitis B virus (HBV) infection is a prominent cause of hepatocellular carcinoma (HCC) but the underlying molecular mechanisms are complex and multiple pathways have been proposed such as the activation of the Wnt-/β-catenin-signalling and dysregulation of E-cadherin/β-catenin adherens junctions. This study aimed to identify mechanisms of how HBV infection and replication as well as HBV X protein (HBx) gene expression in the context of an HBV genome influence Wnt-/β-catenin-signalling and formation of adherens junctions and to which extent HBx contributes to this. Regulation of E-cadherin/β-catenin junctions and β-catenin-signalling as well as the role of HBx were investigated using constructs transiently or stably inducing replication of HBV+/-HBx in hepatoma cell lines. In addition, HCC and adjacent non-tumorous tissue samples from HBV-infected HCC patients and drug interference in HBV-infected cells were studied. Although HBV did not alter overall expression levels of E-cadherin or β-catenin, it diminished their cell surface localization resulting in nuclear translocation of β-catenin and activation of its target genes. In addition, HBV gene expression increased the amount of phosphorylated c-Src kinase. Treatment with Src kinase inhibitor Dasatinib reduced HBV replication, prevented adherens junction disassembly and reduced β-catenin-signalling, while Sorafenib only did so in cells with mutated β-catenin. Interestingly, none of the HBV induced alterations required HBx. Thus, HBV stimulated β-catenin-signalling and induced disassembly of adherens junctions independently of HBx through Src kinase activation. These pathways may contribute to hepatocellular carcinogenesis and seem to be more efficiently inhibited by Dasatinib than by Sorafenib.
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Affiliation(s)
- Gesa von Olshausen
- Department of Internal Medicine I, University Hospital rechts der Isar, Technical University of Munich, Munich, Germany
| | - Maria Quasdorff
- Molecular Infectiology, Institute for Medical Micro biology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,Department of Gastroenterology and Hepatology, University Hospital Cologne, Cologne, Germany
| | - Romina Bester
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Silke Arzberger
- Molecular Infectiology, Institute for Medical Micro biology, Immunology and Hygiene, University Hospital Cologne, Cologne, Germany.,Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Chunkyu Ko
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Maarten van de Klundert
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Ke Zhang
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany
| | - Margarete Odenthal
- Institute of Pathology, University Hospital Cologne, Cologne, Germany.,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
| | - Marc Ringelhan
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany.,Department of Internal Medicine II, University Hospital rechts der Isar, Technical University of Munich, Munich, Germany
| | - Carien M Niessen
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany.,Department of Dermatology, University Hospital of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ulrike Protzer
- Institute of Virology, Technical University of Munich/Helmholtz Zentrum München, Munich, Germany.,German Center for Infection Research (DZIF), Munich Partner Site, Munich, Germany
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15
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Arai E, Miura F, Totoki Y, Yamashita S, Tian Y, Gotoh M, Ojima H, Nakagawa H, Takahashi Y, Nakamura H, Hama N, Kato M, Kimura H, Suzuki Y, Ito T, Shibata T, Kanai Y. Epigenome mapping of human normal purified hepatocytes: personal epigenome variation and genome-epigenome correlation. Epigenomics 2018; 10:955-979. [PMID: 29972026 DOI: 10.2217/epi-2017-0111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
AIM The aim of this study was to reveal the epigenome landscape of human normal hepatocytes. MATERIALS & METHODS Cells purified from partial hepatectomy specimens of Japanese patients were subjected to whole-genome bisulfite sequencing using postbisulfite adaptor tagging, chromatin immunoprecipitation sequencing, RNA sequencing and whole-genome sequencing. RESULTS CHG and CHH methylations were inversely associated with gene expression. Histone modification profiles of personal differentially methylated regions (pDMRs) differed considerably among samples. pDMRs were observed around the transcription start sites of genes whose expression is reportedly regulated by CpG methylation. pDMRs were frequently observed in the vicinity of single-nucleotide variations and insertions/deletions. CONCLUSION Genetic variations may induce epigenetic variations, generating individual differences in the phenotypes of normal hepatocytes through variations in expression.
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Affiliation(s)
- Eri Arai
- Department of Pathology, Keio University School of Medicine, Tokyo 160-8582, Japan.,Division of Molecular Pathology, National Cancer Center Research Institute, Tokyo 104-0045, Japan.,AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan
| | - Fumihito Miura
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Yasushi Totoki
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Satoshi Yamashita
- Division of Epigenomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Ying Tian
- Department of Pathology, Keio University School of Medicine, Tokyo 160-8582, Japan.,AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan
| | - Masahiro Gotoh
- Division of Molecular Pathology, National Cancer Center Research Institute, Tokyo 104-0045, Japan.,AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan
| | - Hidenori Ojima
- Department of Pathology, Keio University School of Medicine, Tokyo 160-8582, Japan.,AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan
| | - Hiroyuki Nakagawa
- Biomedical Department, Cloud Service Division, IT Infrastructure Services Unit, Mitsui Knowledge Industry Co., Ltd, Tokyo 105-6215, Japan
| | - Yoriko Takahashi
- Biomedical Department, Cloud Service Division, IT Infrastructure Services Unit, Mitsui Knowledge Industry Co., Ltd, Tokyo 105-6215, Japan
| | - Hiromi Nakamura
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Natsuko Hama
- Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Mamoru Kato
- Department of Bioinformatics, National Cancer Center Research Institute, Tokyo 104-0045, Japan
| | - Hiroshi Kimura
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Graduate School of Bioscience & Biotechnology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Yutaka Suzuki
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561, Japan
| | - Takashi Ito
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Tatsuhiro Shibata
- AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan.,Division of Cancer Genomics, National Cancer Center Research Institute, Tokyo 104-0045, Japan.,Laboratory of Molecular Medicine, Human Genome Center, The Institute of Medical Sciences, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yae Kanai
- Department of Pathology, Keio University School of Medicine, Tokyo 160-8582, Japan.,Division of Molecular Pathology, National Cancer Center Research Institute, Tokyo 104-0045, Japan.,AMED-CREST, Japan Agency for Medical Research & Development, Tokyo 100-0004, Japan
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16
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Yao JH, Liu ZJ, Yi JH, Wang J, Liu YN. Hepatitis B Virus X Protein Upregulates Intracellular Calcium Signaling by Binding C-terminal of Orail Protein. Curr Med Sci 2018; 38:26-34. [PMID: 30074148 DOI: 10.1007/s11596-018-1843-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 01/15/2018] [Indexed: 12/15/2022]
Abstract
Hepatitis B virus X (HBx) protein plays a pivotal role in the development of hepatitis B virus (HBV)-associated hepatocellular carcinoma. Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein, the mechanism of HBx protein regulating intracellular calcium level remains poorly understood. The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry (SOCE) components, Orail and stromal interaction molecule 1, and then identified the targets of HBx protein, with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis. By employing co-immunoprecipitation and GST-pull-down assay, we found that Orail protein interacted with HBx protein, and the C-terminus of Orail was implicated in the interaction. Confocal microscopy also revealed that HBx protein could co-localize with full-length Orail protein in HEK293 cells. Moreover, live cell calcium imaging exhibited that HBx protein elevated intracellular calcium, possibly by binding to SOCE components. Our results suggest that HBx protein binds to STIM1-Orail complexes to positively regulate the activity of plasma membrane store-operated calcium channels.
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Affiliation(s)
- Jing-Hong Yao
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Zi-Jian Liu
- Department of Anatomy, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Hua Yi
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jun Wang
- Department of Gastroenterology, the Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430014, China
| | - Ya-Nan Liu
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
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17
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Lee SA, Lee SY, Choi YM, Kim H, Kim BJ. Sex disparity in viral load, inflammation and liver damage in transgenic mice carrying full hepatitis B virus genome with the W4P mutation in the preS1 region. World J Gastroenterol 2018; 24:1084-1092. [PMID: 29563753 PMCID: PMC5850128 DOI: 10.3748/wjg.v24.i10.1084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 01/31/2018] [Accepted: 02/09/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To study sex disparity in susceptibility to hepatocellular carcinoma (HCC), we created a transgenic mouse model that expressed the full hepatitis B virus (HBV) genome with the W4P mutation.
METHODS Transgenic mice were generated by transferring the pHY92-1.1x-HBV-full genome plasmid (genotype A2) into C57Bl/6N mice. We compared serum levels of hepatitis B surface antigen (HBsAg), interleukin (IL)-6, and the liver enzymes alanine aminotransferase (ALT) and aspartate transaminase (AST), as well as liver histopathological features in male and female transgenic (W4P TG) mice and in nontransgenic littermates of 10 mo of age.
RESULTS W4P TG males exhibited more pronounced hepatomegaly, significantly increased granule generation in liver tissue, elevated HBsAg expression in the liver and serum, and higher serum ALT and IL-6 levels compared to W4P TG females or littermate control groups.
CONCLUSION Together, our data indicate that the W4P mutation in preS1 may contribute to sex disparity in susceptibility to HCC by causing increased HBV virion replication and enhanced IL-6-mediated inflammation in male individuals. Additionally, our transgenic mouse model that expresses full HBV genome with the W4P mutation in preS1 could be effectively used for the studies of the progression of liver diseases, including HCC.
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Affiliation(s)
- Seoung-Ae Lee
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute and Cancer Research Institute, Seoul National University, College of Medicine, Seoul 110799, South Korea
| | - So-Young Lee
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute and Cancer Research Institute, Seoul National University, College of Medicine, Seoul 110799, South Korea
| | - Yu-Min Choi
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute and Cancer Research Institute, Seoul National University, College of Medicine, Seoul 110799, South Korea
| | - Hong Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute and Cancer Research Institute, Seoul National University, College of Medicine, Seoul 110799, South Korea
| | - Bum-Joon Kim
- Department of Microbiology and Immunology, Biomedical Sciences, Liver Research Institute and Cancer Research Institute, Seoul National University, College of Medicine, Seoul 110799, South Korea
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18
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Downregulation of miR-200a-3p induced by hepatitis B Virus X (HBx) Protein promotes cell proliferation and invasion in HBV-infection-associated hepatocarcinoma. Pathol Res Pract 2017; 213:1464-1469. [PMID: 29103765 DOI: 10.1016/j.prp.2017.10.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hepatitis B Virus X (HBx) Protein encoded by HBV is believed to be the major player in the process of HBV-induced oncogenesis. Ectopic expression of miR-200a-3p was reported to be associated with diverse tumorigenesis. This study aimed to better understand the role of miR-200a-3p and its correlation with HBx in HBV-induced hepatocellular carcinoma (HCC). METHODS In this report, we examined the gene expression using quantitative RT-PCR and protein expression using Western blotting analysis. Cells were transfected with miR-200a-3p mimics or empty vector, and HBx-carrying vector or empty vector. Cell viability was tested using CCK-8 assay. Wound healing assay was performed to assess cell migration while Transwell assay was performed to evaluate cell invasion. RESULTS miR-200a-3p was downregulated in HBV-positive tissue samples compared with HBV-negative tissue samples. This result was further confirmed with HBV-positive and - negative cell lines. HBx protein was overexpressed in HBV-positive cells where expression of miR-200a-3p was significantly suppressed. Increased cell viability, altered cell cycle progression, increased cell migration and invasion occurred in HBx-overexpressed cells compared to its controls. In forced expressed miR-200a-3p cells, cell viability, cell migration and invasion were significantly decreased, and cell cycle status was altered compared to its controls. CONCLUSIONS Taken together, pathogenetic function of HBx is negatively correlated with miR-200a-3p in HBV-cased HCC through regulating cell viability, cell cycle arrest, cell migration and cell invasion.
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19
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Zheng B, Zhu YJ, Wang HY, Chen L. Gender disparity in hepatocellular carcinoma (HCC): multiple underlying mechanisms. SCIENCE CHINA-LIFE SCIENCES 2017; 60:575-584. [PMID: 28547581 DOI: 10.1007/s11427-016-9043-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 02/20/2017] [Indexed: 02/07/2023]
Abstract
On the global scale, hepatitis B virus (HBV) infection is the main cause of hepatocellular carcinoma (HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However, the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.
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Affiliation(s)
- Bo Zheng
- International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China.,National Center for Liver Cancer, Shanghai, 201805, China
| | - Yan-Jing Zhu
- International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China.,National Center for Liver Cancer, Shanghai, 201805, China
| | - Hong-Yang Wang
- International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China. .,National Center for Liver Cancer, Shanghai, 201805, China. .,State Key Laboratory of Oncogenes and related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
| | - Lei Chen
- International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, 200438, China. .,National Center for Liver Cancer, Shanghai, 201805, China.
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20
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Hepatitis B Virus Protein X Induces Degradation of Talin-1. Viruses 2016; 8:v8100281. [PMID: 27775586 PMCID: PMC5086613 DOI: 10.3390/v8100281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 10/06/2016] [Accepted: 10/09/2016] [Indexed: 12/27/2022] Open
Abstract
In the infected human hepatocyte, expression of the hepatitis B virus (HBV) accessory protein X (HBx) is essential to maintain viral replication in vivo. HBx critically interacts with the host damaged DNA binding protein 1 (DDB1) and the associated ubiquitin ligase machinery, suggesting that HBx functions by inducing the degradation of host proteins. To identify such host proteins, we systematically analyzed the HBx interactome. One HBx interacting protein, talin-1 (TLN1), was proteasomally degraded upon HBx expression. Further analysis showed that TLN1 levels indeed modulate HBV transcriptional activity in an HBx-dependent manner. This indicates that HBx-mediated TLN1 degradation is essential and sufficient to stimulate HBV replication. Our data show that TLN1 can act as a viral restriction factor that suppresses HBV replication, and suggest that the HBx relieves this restriction by inducing TLN1 degradation.
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21
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Elbahesh H, Bergmann S, Russell CJ. Focal adhesion kinase (FAK) regulates polymerase activity of multiple influenza A virus subtypes. Virology 2016; 499:369-374. [PMID: 27743963 DOI: 10.1016/j.virol.2016.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 10/01/2016] [Accepted: 10/04/2016] [Indexed: 10/20/2022]
Abstract
Influenza A viruses (IAVs) cause numerous pandemics and yearly epidemics resulting in ~500,000 annual deaths globally. IAV modulates cellular signaling pathways at every step of the infection cycle. Focal adhesion kinase (FAK) has been shown to play a critical role in endosomal trafficking of influenza A viruses, yet it is unclear how FAK kinase activity regulates IAV replication. Using mini-genomes derived from H1N1, H5N1 and H7N9 viruses, we dissected RNA replication by IAVs independent of viral entry or release. Our results show FAK activity promotes efficient IAV polymerase activity and inhibiting FAK activity with a chemical inhibitor or a kinase-dead mutant significantly reduces IAV polymerase activity. Using co-immunoprecipitations and proximity ligation assays, we observed interactions between FAK and the viral nucleoprotein, supporting a direct role of FAK in IAV replication. Altogether, the data indicates that FAK kinase activity is important in promoting IAV replication by regulating its polymerase activity.
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Affiliation(s)
- Husni Elbahesh
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Silke Bergmann
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Charles J Russell
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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22
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Lamontagne J, Mell JC, Bouchard MJ. Transcriptome-Wide Analysis of Hepatitis B Virus-Mediated Changes to Normal Hepatocyte Gene Expression. PLoS Pathog 2016; 12:e1005438. [PMID: 26891448 PMCID: PMC4758756 DOI: 10.1371/journal.ppat.1005438] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 01/13/2016] [Indexed: 12/11/2022] Open
Abstract
Globally, a chronic hepatitis B virus (HBV) infection remains the leading cause of primary liver cancer. The mechanisms leading to the development of HBV-associated liver cancer remain incompletely understood. In part, this is because studies have been limited by the lack of effective model systems that are both readily available and mimic the cellular environment of a normal hepatocyte. Additionally, many studies have focused on single, specific factors or pathways that may be affected by HBV, without addressing cell physiology as a whole. Here, we apply RNA-seq technology to investigate transcriptome-wide, HBV-mediated changes in gene expression to identify single factors and pathways as well as networks of genes and pathways that are affected in the context of HBV replication. Importantly, these studies were conducted in an ex vivo model of cultured primary hepatocytes, allowing for the transcriptomic characterization of this model system and an investigation of early HBV-mediated effects in a biologically relevant context. We analyzed differential gene expression within the context of time-mediated gene-expression changes and show that in the context of HBV replication a number of genes and cellular pathways are altered, including those associated with metabolism, cell cycle regulation, and lipid biosynthesis. Multiple analysis pipelines, as well as qRT-PCR and an independent, replicate RNA-seq analysis, were used to identify and confirm differentially expressed genes. HBV-mediated alterations to the transcriptome that we identified likely represent early changes to hepatocytes following an HBV infection, suggesting potential targets for early therapeutic intervention. Overall, these studies have produced a valuable resource that can be used to expand our understanding of the complex network of host-virus interactions and the impact of HBV-mediated changes to normal hepatocyte physiology on viral replication.
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Affiliation(s)
- Jason Lamontagne
- Graduate Program in Microbiology and Immunology, Graduate School of Biomedical Sciences and Professional Studies, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Joshua C. Mell
- Department of Microbiology and Immunology, Center for Genomic Sciences, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael J. Bouchard
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania, United States of America
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23
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Hepatitis B Virus X Protein Induces Hepatic Steatosis by Enhancing the Expression of Liver Fatty Acid Binding Protein. J Virol 2015; 90:1729-40. [PMID: 26637457 DOI: 10.1128/jvi.02604-15] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 11/23/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Hepatitis B virus (HBV) has been implicated as a potential trigger of hepatic steatosis although molecular mechanisms involved in the pathogenesis of HBV-associated hepatic steatosis still remain elusive. Our prior work has revealed that the expression level of liver fatty acid binding protein 1 (FABP1), a key regulator of hepatic lipid metabolism, was elevated in HBV-producing hepatoma cells. In this study, the effects of HBV X protein (HBx) mediated FABP1 regulation on hepatic steatosis and the underlying mechanism were determined. mRNA and protein levels of FABP1 were measured by quantitative RT-PCR (qPCR) and Western blotting. HBx-mediated FABP1 regulation was evaluated by luciferase assay, coimmunoprecipitation, and chromatin immunoprecipitation. Hepatic lipid accumulation was measured by using Oil-Red-O staining and the triglyceride level. It was found that expression of FABP1 was increased in HBV-producing hepatoma cells, the sera of HBV-infected patients, and the sera and liver tissues of HBV-transgenic mice. Ectopic overexpression of HBx resulted in upregulation of FABP1 in HBx-expressing hepatoma cells, whereas HBx abolishment reduced FABP1 expression. Mechanistically, HBx activated the FABP1 promoter in an HNF3β-, C/EBPα-, and PPARα-dependent manner, in which HBx increased the gene expression of HNF3β and physically interacted with C/EBPα and PPARα. On the other hand, knockdown of FABP1 remarkably blocked lipid accumulation both in long-chain free fatty acids treated HBx-expressing HepG2 cells and in a high-fat diet-fed HBx-transgenic mice. Therefore, FABP1 is a key driver gene in HBx-induced hepatic lipid accumulation via regulation of HNF3β, C/EBPα, and PPARα. FABP1 may represent a novel target for treatment of HBV-associated hepatic steatosis. IMPORTANCE Accumulating evidence from epidemiological and experimental studies has indicated that chronic HBV infection is associated with hepatic steatosis. However, the molecular mechanism underlying HBV-induced pathogenesis of hepatic steatosis still remains to be elucidated. In this study, we found that expression of liver fatty acid binding protein (FABP1) was dramatically increased in the sera of HBV-infected patients and in both sera and liver tissues of HBV-transgenic mice. Forced expression of HBx led to FABP1 upregulation, whereas knockdown of FABP1 remarkably diminished lipid accumulation in both in vitro and in vivo models. It is possible that HBx promotes hepatic lipid accumulation through upregulating FABP1 in the development of HBV-induced nonalcoholic fatty liver disease. Therefore, inhibition of FABP1 might have therapeutic value in steatosis-associated chronic HBV infection.
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García-Niño WR, Zazueta C. Ellagic acid: Pharmacological activities and molecular mechanisms involved in liver protection. Pharmacol Res 2015; 97:84-103. [DOI: 10.1016/j.phrs.2015.04.008] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 04/16/2015] [Accepted: 04/18/2015] [Indexed: 12/23/2022]
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Montella M, D'Arena G, Crispo A, Capunzo M, Nocerino F, Grimaldi M, Barbieri A, D'Ursi AM, Tecce MF, Amore A, Galdiero M, Ciliberto G, Giudice A. Role of Sex Hormones in the Development and Progression of Hepatitis B Virus-Associated Hepatocellular Carcinoma. Int J Endocrinol 2015; 2015:854530. [PMID: 26491442 PMCID: PMC4600563 DOI: 10.1155/2015/854530] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/29/2015] [Accepted: 07/01/2015] [Indexed: 12/25/2022] Open
Abstract
Infection with hepatitis B virus (HBV) is a major risk factor for hepatocellular carcinoma (HCC) in developed countries. Epidemiological reports indicate that the incidence of HBV-related HCC is higher in males and postmenopausal females than other females. Increasing evidence suggests that sex hormones such as androgens and estrogens play an important role in the progression of an HBV infection and in the development of HBV-related HCC. While androgen is supposed to stimulate the androgen signaling pathway and cooperate to the increased transcription and replication of HBV genes, estrogen may play a protecting role against the progression of HBV infections and in the development of HBV-related HCC through decreasing HBV RNA transcription and inflammatory cytokines levels. Additionally, sex hormones can also affect HBV-related hepatocarcinogenesis by inducing epigenetic changes such as the regulation of mRNA levels by microRNAs (miRNAs), DNA methylation, and histone modification in liver tissue. This review describes the molecular mechanisms underlying the gender disparity in HBV-related HCC with the aim of improving the understanding of key factors underneath the sex disparity often observed in HBV infections. Furthermore, the review will propose more effective prevention strategies and treatments of HBV-derived diseases.
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Affiliation(s)
- Maurizio Montella
- Epidemiology Unit, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
- *Maurizio Montella:
| | - Giovanni D'Arena
- Department of Onco-Hematology, IRCCS, Cancer Referral Center of Basilicata, 85028 Rionero in Vulture, Italy
| | - Anna Crispo
- Epidemiology Unit, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | - Mario Capunzo
- Department of Medicine and Surgery, University of Salerno, 84081 Fisciano, Italy
| | - Flavia Nocerino
- Epidemiology Unit, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | - Maria Grimaldi
- Epidemiology Unit, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | - Antonio Barbieri
- Animal Facility, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | - Anna Maria D'Ursi
- Department of Pharmacy, University of Salerno, 84084 Fisciano, Salerno, Italy
| | - Mario Felice Tecce
- Department of Pharmacy, University of Salerno, 84084 Fisciano, Salerno, Italy
| | - Alfonso Amore
- Department of Surgery, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | | | - Gennaro Ciliberto
- National Cancer Institute “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
| | - Aldo Giudice
- Epidemiology Unit, National Cancer Institute of Naples “G. Pascale Foundation”, IRCCS, 80131 Naples, Italy
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Focal adhesion kinase is involved in rabies virus infection through its interaction with viral phosphoprotein P. J Virol 2014; 89:1640-51. [PMID: 25410852 DOI: 10.1128/jvi.02602-14] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED The rabies virus (RABV) phosphoprotein P is a multifunctional protein: it plays an essential role in viral transcription and replication, and in addition, RABV P has been identified as an interferon antagonist. Here, a yeast two-hybrid screen revealed that RABV P interacts with the focal adhesion kinase (FAK). The binding involved the 106-to-131 domain, corresponding to the dimerization domain of P and the C-terminal domain of FAK containing the proline-rich domains PRR2 and PRR3. The P-FAK interaction was confirmed in infected cells by coimmunoprecipitation and colocalization of FAK with P in Negri bodies. By alanine scanning, we identified a single mutation in the P protein that abolishes this interaction. The mutant virus containing a substitution of Ala for Arg in position 109 in P (P.R109A), which did not interact with FAK, is affected at a posttranscriptional step involving protein synthesis and viral RNA replication. Furthermore, FAK depletion inhibited viral protein expression in infected cells. This provides the first evidence of an interaction of RABV with FAK that positively regulates infection. IMPORTANCE Rabies virus exhibits a small genome that encodes a limited number of viral proteins. To maintain efficient virus replication, some of them are multifunctional, such as the phosphoprotein P. We and others have shown that P establishes complex networks of interactions with host cell components. These interactions have revealed much about the role of P and about host-pathogen interactions in infected cells. Here, we identified another cellular partner of P, the focal adhesion kinase (FAK). Our data shed light on the implication of FAK in RABV infection and provide evidence that P-FAK interaction has a proviral function.
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Chen WN, Liu LL, Jiao BY, Lin WS, Lin XJ, Lin X. Hepatitis B virus X protein increases the IL-1β-induced NF-κB activation via interaction with evolutionarily conserved signaling intermediate in Toll pathways (ECSIT). Virus Res 2014; 195:236-45. [PMID: 25449573 DOI: 10.1016/j.virusres.2014.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/28/2014] [Accepted: 10/28/2014] [Indexed: 02/07/2023]
Abstract
Hepatitis B virus X protein (HBx) transactivates multiple transcription factors including nuclear factor-kappa B (NF-κB) that regulates inflammatory-related genes. However, the regulatory mechanism of HBx in NF-κB activation remains largely unknown. This study reports that HBx augments the interleukin-1β (IL-1β)-induced NF-κB activation via interaction with a Toll-like receptor (TLR) adapter protein, ECSIT (evolutionarily conserved signaling intermediate in Toll pathways). GST pull-down and co-immunoprecipitation analyses showed that HBx interacted with ECSIT. Deletion analysis of HBx in a CytoTrap two-hybrid system revealed that the interaction region of HBx for ECSIT was attributed to aa 51-80. Co-transfection of HBx and ECSIT in IL-1β-stimulated cells appeared to activate IKK and IκB signaling pathway as phosphorylation of both IKK α/β and IκBα was increased whereas knockdown of ECSIT or HBxΔ51-80 mutant attenuated the phosphorylation. As a consequence of IκBα degradation, NF-κB was activated as evidenced by increases in NF-κB transcriptional activity and the nuclear translocation of p65 and p50 that resulted in the induction of IL-10. In contrast, knockdown of ECSIT by siRNA or treatment with an NF-κB selective inhibitor (helenalin) abolished the NF-κB activation and IL-10 expression. We conclude that ECSIT appears to be a novel HBx-interacting signal molecule and their interaction is mechanistically important in IL-1β induction of NF-κB activation.
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Affiliation(s)
- Wan-nan Chen
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China; Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China
| | - Ling-ling Liu
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Bo-yan Jiao
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Wan-song Lin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
| | - Xin-jian Lin
- Department of Medicine and UC San Diego Moores Cancer Center, University of California-San Diego, CA, USA.
| | - Xu Lin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China; Key Laboratory of Tumor Microbiology, Department of Medical Microbiology, Fujian Medical University, Fuzhou, China.
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The hepatitis B virus (HBV) HBx protein activates AKT to simultaneously regulate HBV replication and hepatocyte survival. J Virol 2014; 89:999-1012. [PMID: 25355887 DOI: 10.1128/jvi.02440-14] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED Chronic infection with hepatitis B virus (HBV) is a risk factor for developing liver diseases such as hepatocellular carcinoma (HCC). HBx is a multifunctional protein encoded by the HBV genome; HBx stimulates HBV replication and is thought to play an important role in the development of HBV-associated HCC. HBx can activate the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway in some cell lines; however, whether HBx regulates PI3K/AKT signaling in normal hepatocytes has not been evaluated. In studies described here, we assessed HBx activation of PI3K/AKT signaling in an ex vivo model of cultured primary hepatocytes and determined how this HBx activity affects HBV replication. We report that HBx activates AKT in primary hepatocytes and that the activation of AKT decreases HBV replication and HBV mRNA and core protein levels. We show that the transcription factor hepatocyte nuclear factor 4α (HNF4α) is a target of HBx-regulated AKT, and we link HNF4α to HBx-regulated AKT modulation of HBV transcription and replication. Although we and others have shown that HBx stimulates and is likely required for HBV replication, we now report that HBx also activates signals that can diminish the overall level of HBV replication. While this may seem counterintuitive, we show that an important effect of HBx activation of AKT is inhibition of apoptosis. Consequently, our studies suggest that HBx balances HBV replication and cell survival by stimulating signaling pathways that enhance hepatocyte survival at the expense of higher levels of HBV replication. IMPORTANCE Chronic hepatitis B virus (HBV) infection is a common cause of the development of liver cancer. Regulation of cell signaling pathways by the HBV HBx protein is thought to influence the development of HBV-associated liver cancer. HBx stimulates, and may be essential for, HBV replication. We show that HBx activates AKT in hepatocytes to reduce HBV replication. While this seems contradictory to an essential role of HBx during HBV replication, HBx activation of AKT inhibits hepatocyte apoptosis, and this may facilitate persistent, noncytopathic HBV replication. AKT regulates HBV replication by reducing the activity of the transcription factor hepatocyte nuclear factor 4α (HNF4α). HBx activation of AKT may contribute to the development of liver cancer by facilitating persistent HBV replication, augmenting the dedifferentiation of hepatocytes by inhibiting HNF4α functions, and activating AKT-regulated oncogenic pathways. AKT-regulated factors may provide therapeutic targets for inhibiting HBV replication and the development of HBV-associated liver cancer.
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Sagar M, Pathak RK, Pandey RK, Singh DB, Pandey N, Gupta MK. Binding affinity analysis and ADMET prediction of epigallocatechine gallate (EGCG) derivatives for AP-1 protein: a drug target for liver cancer. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s13721-014-0066-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Hösel M, Lucifora J, Michler T, Holz G, Gruffaz M, Stahnke S, Zoulim F, Durantel D, Heikenwalder M, Nierhoff D, Millet R, Salvetti A, Protzer U, Büning H. Hepatitis B virus infection enhances susceptibility toward adeno-associated viral vector transduction in vitro and in vivo. Hepatology 2014; 59:2110-20. [PMID: 24425003 DOI: 10.1002/hep.26990] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 12/23/2013] [Indexed: 12/20/2022]
Abstract
UNLABELLED Gene therapy has become an accepted concept for the treatment of a variety of different diseases. In contrast to preclinical models, subjects enrolled in clinical trials, including gene therapy, possess a history of infection with microbes that may influence its safety and efficacy. Especially, viruses that establish chronic infections in the liver, one of the main targets for in vivo gene therapy, raise important concerns. Among them is the hepatitis B virus (HBV), which has chronically infected more than 350 million people worldwide. Here, we investigated the effect of HBV on adeno-associated viral (AAV) vectors, the most frequently applied gene transfer vehicles for in vivo gene therapy. Unexpectedly, we found that HBV greatly improved AAV transduction in cells replicating HBV and identified HBV protein x (HBx) as a key factor. Whereas HBV-positive and -negative cells were indistinguishable with respect to cell-entry efficiency, significantly higher numbers of AAV vector genomes were successfully delivered to the nucleus in the presence of HBV. The HBV-promoting effect was abolished by inhibitors of phosphatidylinositol 3-kinase (PI3K). PI3K was required for efficient trafficking of AAV to the nucleus and was enhanced in HBV-replicating cells and upon HBx expression. Enhancement of AAV transduction was confirmed in vivo using HBV transgenic mice and could successfully be applied to inhibit HBV progeny release. CONCLUSION Our results demonstrate that acute, as well as chronic, infections with unrelated viruses change the intracellular milieu, thereby likely influencing gene therapy outcomes. In the case of HBV, HBx-mediated enhancement of AAV transduction is an advantage that could be exploited for development of novel treatments of HBV infection.
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Affiliation(s)
- Marianna Hösel
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; German Center for Infection Research, Partner sites Bonn-Cologne and Munich, Germany; Department I of Internal Medicine, University Hospital Cologne, Cologne, Germany
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Liu WC, Liu QY. Molecular mechanisms of gender disparity in hepatitis B virus-associated hepatocellular carcinoma. World J Gastroenterol 2014; 20:6252-6261. [PMID: 24876746 PMCID: PMC4033463 DOI: 10.3748/wjg.v20.i20.6252] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 12/22/2013] [Accepted: 01/08/2014] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis B virus (HBV) infection is one of the most common causes of hepatocellular carcinoma (HCC), a malignant tumor with high mortality worldwide. One remarkable clinical feature of HBV-related HCC is that its incidence is higher in males and postmenopausal females compared to other females. Increasing evidence indicates that HBV-associated HCC may involve gender disparity and that it may be a type of hormone-responsive malignant tumor. Sex hormones, such as androgen and estrogen, have been shown to play very different roles in the progression of an HBV infection and in the development of HBV-related HCC. Through binding to their specific cellular receptors and affecting the corresponding signaling pathways, sex hormones can regulate the transactivation of HBx, cause the chronic release of inflammatory cytokines in the hepatocellular microenvironment, and participate in epigenetic and genetic alternations in hepatocytes. All of these functions may be related to the initiation and progression of HBV-associated HCC. A thorough investigation of the molecular mechanisms underlying the gender-related disparity in HBV-related HCC should provide a new perspective for better understanding its pathogenesis and exploring more effective methods for the prevention and treatment of this disease.
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Xie Q, Chen L, Shan X, Shan X, Tang J, Zhou F, Chen Q, Quan H, Nie D, Zhang W, Huang AL, Tang N. Epigenetic silencing of SFRP1 and SFRP5 by hepatitis B virus X protein enhances hepatoma cell tumorigenicity through Wnt signaling pathway. Int J Cancer 2014; 135:635-46. [PMID: 24374650 DOI: 10.1002/ijc.28697] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2013] [Accepted: 12/12/2013] [Indexed: 12/12/2022]
Abstract
Secreted frizzled-related proteins (SFRPs) are antagonists of the Wnt signaling pathway whose epigenetic downregulation have been shown to be involved in hepatocarcinogenesis. However, dysregulation of SFRPs induced by hepatitis B virus (HBV) X protein (HBx) has never been studied in HBV-related hepatocellular carcinoma (HBV-HCC). In this study, we sought to determine the clinical significance and underlying mechanism of HBx-induced SFRPs dysregulation in hepatoma cells and HBV-HCC patients. Our results showed that SFRP1 and SFRP5 expression were dramatically decreased by HBx in hepatoma cells. The repressed expression in hepatoma cells was partially rescued by a DNA methylation inhibitor and synergistically increased by a combination treatment with a histone deacetyltransferases inhibitor. In addition, we identified that SFRP1 and SFRP5 promoters were hypermethylated in both HBx-expressing hepatoma cells and HBV-HCC tissues. Downregulation of SFRP1 and SFRP5 in HBV-HCC tissues was significantly correlated with overexpression of DNA methyltransferase 1 (DNMT1) and poor tumor differentiation. HBx facilitated the binding of DNMT1 and DNMT3A to SFRP1 and SFRP5 promoters, and resulted in epigenetic silencing of SFRP1 and SFRP5. Moreover, overexpression of SFRP1, SFRP5 or RNA interference mediated silencing of DNMT1 inactivated the Wnt signaling pathway and decreased the expression levels of Wnt target genes c-Myc and CyclinD1, thus impeding HCC growth in vitro and in vivo, and regressing HBx-induced epithelial-mesenchymal transition (EMT). Our findings strongly suggest that epigenetic silencing of SFRP1 and SFRP5 by HBx allows constitutive activation of Wnt signaling pathway and hence contributes to hepatocarcinogenesis.
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Affiliation(s)
- Qing Xie
- The Second Affiliated Hospital and the Key Laboratory of Molecular Biology of Infectious Diseases designated by the Chinese Ministry of Education, Chongqing Medical University, Chongqing, China
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Wu YL, Wang D, Peng XE, Chen YL, Zheng DL, Chen WN, Lin X. Epigenetic silencing of NAD(P)H:quinone oxidoreductase 1 by hepatitis B virus X protein increases mitochondrial injury and cellular susceptibility to oxidative stress in hepatoma cells. Free Radic Biol Med 2013; 65:632-644. [PMID: 23920313 DOI: 10.1016/j.freeradbiomed.2013.07.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 12/31/2022]
Abstract
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a phase II enzyme that participates in the detoxification of dopamine-derived quinone molecules and reactive oxygen species. Our prior work using a proteomic approach found that NQO1 protein levels were significantly decreased in stable hepatitis B virus (HBV)-producing hepatoma cells relative to the empty-vector-transfected controls. However, the mechanism and biological significance of the NQO1 suppression remain elusive. In this study we demonstrate that HBV X protein (HBx) induces epigenetic silencing of NQO1 in hepatoma cells through promoter hypermethylation via recruitment of DNA methyltransferase DNMT3A to the promoter region of the NQO1 gene. In HBV-related hepatocellular carcinoma (HCC) specimens, HBx expression was correlated negatively to NQO1 transcripts but positively to NQO1 promoter hypermethylation. Downregulation of NQO1 by HBx reduced intracellular glutathione levels, impaired mitochondrial function, and increased susceptibility of hepatoma cells to oxidative stress-induced cell injury. These results suggest a novel mechanism for HBV-mediated pathogenesis of chronic liver diseases, including HCC.
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Affiliation(s)
- Yun-Li Wu
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Dong Wang
- Department of Hepatobiliary and Pancreatic Surgery, Union Clinical Medical College, Fujian Medical University, Fuzhou 350108, China
| | - Xian-E Peng
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Yan-Ling Chen
- Department of Hepatobiliary and Pancreatic Surgery, Union Clinical Medical College, Fujian Medical University, Fuzhou 350108, China
| | - Da-Li Zheng
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Wan-Nan Chen
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China; Key Laboratory of Tumor Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China
| | - Xu Lin
- Key Laboratory of Ministry of Education for Gastrointestinal Cancer, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China; Key Laboratory of Tumor Microbiology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350108, China.
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Abstract
Intracellular free Ca(2+) ([Ca(2+)]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca(2+) signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca(2+) signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca(2+) signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca(2+)]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca(2+) signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca(2+) signaling in the liver, and the role of Ca(2+) signaling in liver disease.
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Affiliation(s)
- Maria Jimena Amaya
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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Kuo CY, Chou TY, Chen CM, Tsai YF, Hwang GY, Hwang TL. Hepatitis B virus X protein disrupts stress fiber formation and triggers apoptosis. Virus Res 2013; 175:20-9. [PMID: 23591626 DOI: 10.1016/j.virusres.2013.03.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/22/2013] [Accepted: 03/26/2013] [Indexed: 12/28/2022]
Abstract
Cytoskeletal proteins are key participants in the cellular progression to apoptosis. In a previous study we injected nude mice with CCL13-HBx cells and identified in contrast to non-HBx transfected cells a differentially phosphorylated myosin light chain (p-MLC) by two-dimensional PAGE and mass spectrometry of the tumor material. To investigate the role of HBx in myosin light chain kinase (MLCK) signaling pathways, we analyzed the key molecules, p-MLC and MLCK, by western blotting. Immunofluorescence staining analysis showed that HBx disrupted stress fiber formation and that focal adhesion kinase (FAK) and integrin-linked kinase (ILK) were regulated by HBx-mediated phosphatase and tensin homolog (PTEN). We also used pharmacological inhibitors to explore the correlation between cytoskeletal rearrangements and HBx-mediated cell apoptosis via an MLCK and a PTEN-dependent pathway. The results showed that both ML9 and bvp restored the effects caused by HBx induction. Our findings suggest that HBx disrupts stress fiber formation and triggers apoptosis via an MLCK and a PTEN-dependent pathway.
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Affiliation(s)
- Chan-Yen Kuo
- Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan
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Rawat S, Clippinger AJ, Bouchard MJ. Modulation of apoptotic signaling by the hepatitis B virus X protein. Viruses 2012; 4:2945-72. [PMID: 23202511 PMCID: PMC3509679 DOI: 10.3390/v4112945] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/23/2012] [Accepted: 10/31/2012] [Indexed: 12/18/2022] Open
Abstract
Worldwide, an estimated 350 million people are chronically infected with the Hepatitis B Virus (HBV); chronic infection with HBV is associated with the development of severe liver diseases including hepatitis and cirrhosis. Individuals who are chronically infected with HBV also have a significantly higher risk of developing hepatocellular carcinoma (HCC) than uninfected individuals. The HBV X protein (HBx) is a key regulatory HBV protein that is important for HBV replication, and likely plays a cofactor role in the development of HCC in chronically HBV-infected individuals. Although some of the functions of HBx that may contribute to the development of HCC have been characterized, many HBx activities, and their putative roles during the development of HBV-associated HCC, remain incompletely understood. HBx is a multifunctional protein that localizes to the cytoplasm, nucleus, and mitochondria of HBV‑infected hepatocytes. HBx regulates numerous cellular signal transduction pathways and transcription factors as well as cell cycle progression and apoptosis. In this review, we will summarize reports in which the impact of HBx expression on cellular apoptotic pathways has been analyzed. Although various effects of HBx on apoptotic pathways have been observed in different model systems, studies of HBx activities in biologically relevant hepatocyte systems have begun to clarify apoptotic effects of HBx and suggest mechanisms that could link HBx modulation of apoptotic pathways to the development of HBV-associated HCC.
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Affiliation(s)
- Siddhartha Rawat
- Graduate Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19102, USA;
| | - Amy J. Clippinger
- Department of Cancer Biology, Abramson Family Cancer Research Institute, School of Medicine, University of Pennsylvania Philadelphia, PA 19104, USA;
| | - Michael J. Bouchard
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Luo L, Chen S, Gong Q, Luo N, Lei Y, Guo J, He S. Hepatitis B virus X protein modulates remodelling of minichromosomes related to hepatitis B virus replication in HepG2 cells. Int J Mol Med 2012; 31:197-204. [PMID: 23128981 DOI: 10.3892/ijmm.2012.1165] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 08/14/2012] [Indexed: 11/05/2022] Open
Abstract
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is organised into minichromosomes by histone and non-histone proteins. Remodelling of minichromosomes is crucial for the regulation of HBV replication, which is dependent on the presence of the hepatitis B virus X protein (HBx). However, the mechanisms of HBx-dependent HBV replication remain obscure. The objective of this study was to investigate the mechanism of HBx-dependent HBV replication through the pathway of chromatin remodelling. The role of HBx was investigated by transfecting human HepG2 cells with the linear full-length HBV genome (wild-type) or HBx-deficient mutant HBV DNA (HBx mutant). Our results showed that although the formation of cccDNA was not affected by HBx, HBV replication, transcription and antigen secretion were all significantly reduced, resulting from the absence of HBx. The acetylation, mono-methylation and phosphorylation of cccDNA-bound histone H3 were associated with HBV replication. In addition, the levels of cccDNA-bound methylated, phosphorylated and acetylated histone H3 decreased sharply in HBx mutant HBV DNA. HBx modulated not only the status of acetylation but also the methylation and phosphorylation of histone H3 bound to the cccDNA during HBV replication in HepG2 cells. These findings suggest that HBx plays an important role in modulating the remodelling of minichromosomes related to HBV replication and it may regulate viral replication through the pathway of chromatin remodelling.
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Affiliation(s)
- Li Luo
- Department of Gastroenterology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, PR China
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Abstract
As one of the principal causes of liver diseases, such as chronic hepatitis B, hepatic cirrhosis and hepatocellular carcinoma (HCC), hepatitis B virus (HBV) infection has been a major health problem worldwide. It is estimated that more than 500 million individuals have been infected with HBV worldwide and 1 million die of HBV infection-associated diseases annually. HBV X protein (HBx) is a multifunctional protein that can modulate various cellular processes and plays a crucial role in the pathogenesis of HCC. In recent years, the role of HBx in HBV replication has been more or less confirmed. In addition, more and more natural HBx truncated mutants and their roles in HBV replication have been found. This review aims to elucidate the roles of HBx and truncated HBx in HBV replication.
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The hepatitis B virus X protein elevates cytosolic calcium signals by modulating mitochondrial calcium uptake. J Virol 2011; 86:313-27. [PMID: 22031934 DOI: 10.1128/jvi.06442-11] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Chronic hepatitis B virus (HBV) infections are associated with the development of hepatocellular carcinoma (HCC). The HBV X protein (HBx) is thought to play an important role in the development of HBV-associated HCC. One fundamental HBx function is elevation of cytosolic calcium signals; this HBx activity has been linked to HBx stimulation of cell proliferation and transcription pathways, as well as HBV replication. Exactly how HBx elevates cytosolic calcium signals is not clear. The studies described here show that HBx stimulates calcium entry into cells, resulting in an increased plateau level of inositol 1,4,5-triphosphate (IP3)-linked calcium signals. This increased calcium plateau can be inhibited by blocking mitochondrial calcium uptake and store-operated calcium entry (SOCE). Blocking SOCE also reduced HBV replication. Finally, these studies also demonstrate that there is increased mitochondrial calcium uptake in HBx-expressing cells. Cumulatively, these studies suggest that HBx can increase mitochondrial calcium uptake and promote increased SOCE to sustain higher cytosolic calcium and stimulate HBV replication.
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Molecular mechanism for the involvement of nuclear receptor FXR in HBV-associated hepatocellular carcinoma. Acta Pharm Sin B 2011. [DOI: 10.1016/j.apsb.2011.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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41
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Martin-Vilchez S, Lara-Pezzi E, Trapero-Marugán M, Moreno-Otero R, Sanz-Cameno P. The molecular and pathophysiological implications of hepatitis B X antigen in chronic hepatitis B virus infection. Rev Med Virol 2011; 21:315-29. [PMID: 21755567 DOI: 10.1002/rmv.699] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Revised: 05/23/2011] [Accepted: 05/26/2011] [Indexed: 12/16/2022]
Abstract
Hepatitis B virus is considered one of the most significant environmental carcinogens in humans. Because the mechanisms of HBV replication and the development of hepatocellular carcinoma (HCC) are partially known, HBV-associated pathogenesis remains a challenge to increase its understanding. Evidence suggests that the regulatory protein hepatitis B virus X (HBx) mediates the establishment and maintenance of the chronic carrier state. HBx is a multifunctional and potentially oncogenic protein that is conserved among mammalian hepadnaviruses; it is produced very early after infection and throughout the chronic phase. HBx exerts its effects by interacting with cellular proteins and activating various signaling pathways. HBx stimulates the transcription of genes that regulate cell growth, apoptosis, and DNA repair. It also interacts with proteasome subunits and affects mitochondrial stability. Moreover, HBx participates in processes that are associated with the progression of chronic liver disease, including angiogenesis and fibrosis. This review discusses the function of HBx in the life cycle of HBV and its contribution to the pathogenesis of HCC.
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Affiliation(s)
- Samuel Martin-Vilchez
- CIBERehd, ISCIII, Madrid, Spain; Servicio Digestivo, Hospital Universitario "La Princesa" and Instituto de Investigación Biomédica "La Princesa", Madrid, Spain
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Xie HY, Cheng J, Xing CY, Wang JJ, Su R, Wei XY, Zhou L, Zheng SS. Evaluation of hepatitis B viral replication and proteomic analysis of HepG2.2.15 cell line after knockdown of HBx. Hepatobiliary Pancreat Dis Int 2011; 10:295-302. [PMID: 21669574 DOI: 10.1016/s1499-3872(11)60049-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hepatitis B virus (HBV) is one of the major pathogens of human liver disease. Studies have shown that HBV X protein (HBx) plays an important role in promoting viral gene expression and replication. In this study we performed a global proteomic profiling to identify the downstream functional proteins of HBx, thereby detecting the mechanisms of action of HBx on virion replication. METHODS HBx in the HepG2.2.15 cell line was knocked down by the transfection of small interfering RNA (siRNA). The replication level of HBV was evaluated by microparticle enzyme immunoassay analysis of HBsAg and HBeAg in the culture supernatant, and real-time quantitative PCR analysis of HBV DNA. Two-dimensional electrophoresis combined with MALDI-TOF/TOF was performed to analyze the changes in protein expression profile after treatment with HBx siRNA. RESULTS Knockdown of HBx disturbed HBV replication in vitro. HBx target siRNA significantly inhibited the expression of HBsAg, HBeAg and the replication of HBV DNA. Twelve significantly changed proteins (7 upregulated and 5 downregulated) were successfully identified by MALDI-TOF/TOF using proteomics differential expression analysis after the knockdown of HBx. Among these identified proteins, HSP70 was validated by Western blotting. CONCLUSION The results of the study indicated the positive effect of HBx on HBV replication, and a group of downstream target proteins of HBx may be responsible for this effect.
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Affiliation(s)
- Hai-Yang Xie
- Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, and Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
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Golubovskaya VM. Focal adhesion kinase as a cancer therapy target. Anticancer Agents Med Chem 2011; 10:735-41. [PMID: 21214510 DOI: 10.2174/187152010794728648] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 10/07/2010] [Indexed: 11/22/2022]
Abstract
Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that resides at the sites of focal adhesions. The 125 kDa FAK protein is encoded by the FAK gene located on human chromosome 8q24. Structurally, FAK consists of an amino-terminal regulatory FERM domain, a central catalytic kinase domain, and a carboxy-terminal focal adhesion targeting domain. FAK has been shown to be an important mediator of cell adhesion, growth, proliferation, survival, angiogenesis and migration, all of which are often disrupted in cancer cells. Normal tissues have low expression of FAK, while primary and metastatic tumors significantly overexpress this protein. This review summarizes expression of FAK by immunohistochemical staining in different tumor types and presents several FAK inhibition therapy approaches.
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Affiliation(s)
- Vita M Golubovskaya
- Department of Surgical Oncology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
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Shukla R, Yue J, Siouda M, Gheit T, Hantz O, Merle P, Zoulim F, Krutovskikh V, Tommasino M, Sylla BS. Proinflammatory cytokine TNF-α increases the stability of hepatitis B virus X protein through NF-κB signaling. Carcinogenesis 2011; 32:978-85. [PMID: 21459755 DOI: 10.1093/carcin/bgr057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) X protein (HBx) is a key player in HBV-induced hepatocellular carcinoma (HCC). HBx interacts with several cell signaling molecules, leading to activation of various transcription factors including nuclear factor-kappaB (NF-κB). Activated NF-κB signaling is implicated in many human cancers including HCC. Here, we present evidence that the NF-κB signaling activator, tumor necrosis factor (TNF)-α, induces the accumulation of HBx in cells by increasing protein stability due to reduced proteasomal degradation. The effects of TNF-α on HBx protein stability are mediated via activated NF-κB effector kinases IKKα and IKKβ and p65. The non-IKK-phosphorylable p65-S534A mutant did not induce HBx protein stability; hence, phosphorylation of p65 by IKK is a key step in TNF-α-induced stabilization of HBx. Phospho-p65 showed higher affinity to HBx compared with the non-phosphorylable p65 mutant, suggesting that the interaction of phospho-p65 with HBx might be important for HBx stabilization. We also show that the increased level of HBx in cells cooperates with TNF-α toward activation of NF-κB and expression of NF-κB-regulated genes, indicating a positive feedback loop between HBx and NF-κB signaling. Overall, our study provides evidence for interplay between HBx and NF-κB signaling, which may account for HBV-mediated liver carcinogenesis.
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Affiliation(s)
- Ruchi Shukla
- Infections and Cancer Biology Group, International Agency for Research on Cancer, 150 cours Albert-Thomas, 69372 Lyon Cedex 08, France
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Iyer S, Groopman JD. Interaction of mutant hepatitis B X protein with p53 tumor suppressor protein affects both transcription and cell survival. Mol Carcinog 2011; 50:972-80. [PMID: 21438026 DOI: 10.1002/mc.20767] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Revised: 12/29/2010] [Accepted: 02/17/2011] [Indexed: 12/16/2022]
Abstract
This study examines the differential activities between wild-type Hepatitis B virus X protein (WtHBx) and a mutant HBx (MutHBx), which bears a hotspot mutation at nucleotides 1,762 and 1,764, resulting in a lysine to methionine change at codon 130 and a valine to isoleucine change at codon 131. This mutation leads to hepatocellular carcinoma, and we evaluated how WtHBx and MutHBx proteins differ in their interactions with the p53 tumor suppressor protein. This was experimentally addressed through co-immunoprecipitation assays examining the interaction between WtHBx and MutHBx proteins with p53, reporter assays determining the impact of the HBx proteins on p53-mediated gene transcription, and clonogenic survival assays evaluating the effect of HBx on cell growth in lines of varying p53-expression status. Both WtHBx and MutHBx proteins physically interact with p53 protein, but have different impacts on p53-mediated gene transcription. WtHBx did not effect p53-mediated gene transcription, whereas MutHBx inhibited it (P < 0.01). MutHBx inhibited colony formation in p53-proficient cells (P < 0.01), but not p53-deficient lines. Although both HBx proteins interact with p53, they affect p53-mediated gene transcription differently. WtHBx has no effect, whereas MutHBx inhibits it. In clonogenic survival assays, MutHBx inhibited cell growth in p53-proficient cells rather than enhanced it. This suggests that for MutHBx to behave oncogenically, the p53 pathway must be crippled or absent. This study has identified some important novel ways in which WtHBx and MutHBx differentially interact with p53 and this could begin to form the cellular explanation for the association between this particular mutant and liver cancer.
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Affiliation(s)
- Shoba Iyer
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
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Liu Q, Chen J, Liu L, Zhang J, Wang D, Ma L, He Y, Liu Y, Liu Z, Wu J. The X protein of hepatitis B virus inhibits apoptosis in hepatoma cells through enhancing the methionine adenosyltransferase 2A gene expression and reducing S-adenosylmethionine production. J Biol Chem 2011; 286:17168-80. [PMID: 21247894 PMCID: PMC3089560 DOI: 10.1074/jbc.m110.167783] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The X protein (HBx) of hepatitis B virus (HBV) is involved in the development of hepatocellular carcinoma (HCC), and methionine adenosyltransferase 2A (MAT2A) promotes the growth of liver cancer cells through altering S-adenosylmethionine homeostasis. Thus, we speculated that a link between HBx and MAT2A may contribute to HCC development. In this study, the effects of HBx on MAT2A expression and cell apoptosis were investigated, and the molecular mechanism by which HBx and MAT2A regulate tumorigenesis was evaluated. Results from immunohistochemistry analyses of 37 pairs of HBV-associated liver cancer tissues/corresponding peritumor tissues showed that HBx and MAT2A are highly expressed in most liver tumor tissues. Our in vitro results revealed that HBx activates MAT2A expression in a dose-dependent manner in hepatoma cells, and such regulation requires the cis-regulatory elements NF-κB and CREB on the MAT2A gene promoter. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) further demonstrated that HBx facilitates the binding of NF-κB and CREB to MAT2A gene promoter. In addition, overexpression of HBx or MAT2A inhibits cell apoptosis, whereas knockdown of MAT2A expression stimulates apoptosis in hepatoma cells. Furthermore, we demonstrated that HBx reduces MAT1A expression and AdoMet production but enhances MAT2β expression. Thus, we proposed that HBx activates MAT2A expression through NF-κB and CREB signaling pathways to reduce AdoMet production, inhibit hepatoma cell apoptosis, and perhaps enhance HCC development. These findings should provide new insights into our understanding how the molecular mechanisms underline the effects of HBV infection on the production of MAT2A and the development of HCC.
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Affiliation(s)
- Quanyan Liu
- Department of General Surgery, Research Center of Digestive Diseases, Zhongnan Hospital, Wuhan 430071, China
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47
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Fan W, Shi B, Wei H, Du G, Song S. Comparison of hepatitis B X gene mutation between patients with hepatocellular carcinoma and patients with chronic hepatitis B. Virus Genes 2010; 42:162-70. [PMID: 21161360 DOI: 10.1007/s11262-010-0557-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 11/19/2010] [Indexed: 12/14/2022]
Abstract
Hepatitis B virus (HBV), a major causative agent of hepatocellular carcinoma (HCC), encodes an oncogenic X protein (HBx) that transcriptionally activates multiple viral and cellular promoters. The present study aimed to identify the specific gene mutation related to the clinical outcome of HCC. Seventy-two HBV-infected patients (38 with chronic HBV infection and 34 with HCC) with well-characterized clinical profiles were enrolled. The HBx region was amplified from patient serum samples and analyzed by sequencing. Genotypes were determined using the National Center for Biotechnology Information genotype tool. All isolates were genotype B or C. Enhancer II nucleotide substitutions in the HCC group were significantly different from those in the chronic hepatitis B (CHB) group (Ρ < 0.05). HCC patients with genotype C had a higher risk of harboring the 1762/1764 double mutation than those with genotype B. The incidence of the 1762/1764 double mutation was higher in the high viral load group (>10(6) copies/ml) than in the low viral load group (≤10(6) copies/ml) (P = 0.03). The 1762/1764 double mutations may be related to the genotype and viral load. We found significantly more direct repeat sequence 1 (DR1) nucleotide substitutions in the HCC group (32.4%, 11/34) than in the CHB group (10.5%, 4/38) (Ρ < 0.05). Patients with higher viral load and genotype C had a higher incidence of 1762/1764 double mutations, which may not be related with development of HCC. Enhancer II and DR1 may play an important role in HCC development via nucleotide substitution.
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Affiliation(s)
- Wenmei Fan
- Institute of Organ Transplantation, Chinese PLA Postgraduate Medical School, The No. 309th Hospital of PLA, Beijing, China.
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48
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Gong Q, He S. Advances in understanding the biological roles of HBx. Shijie Huaren Xiaohua Zazhi 2010; 18:3656-3661. [DOI: 10.11569/wcjd.v18.i34.3656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV) is the leading cause of liver cancer. Globally, there are over 350 million individuals chronically infected with HBV, and approximately 25% of these individuals will develop hepatocellular carcinoma (HCC). HBV is the prototype virus of the hepadnavirus family. The genome of HBV is circular and contains four open reading frames (ORFs). The HBx protein encoded by the X region of HBV is a multifunctional regulatory protein that possesses a wide transactivation activity and plays critical roles in regulating intracellular signal transduction, viral replication and transcription, cell proliferation and apoptosis, protein degradation, and heredity stability of hepatocytes. Due to its important roles in the development of chronic liver diseases, the research on the HBx protein has become a hot topic in recent years. In this paper, we will summarize the latest advances in understanding the biological roles of the HBx protein.
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Gearhart TL, Bouchard MJ. Replication of the hepatitis B virus requires a calcium-dependent HBx-induced G1 phase arrest of hepatocytes. Virology 2010; 407:14-25. [PMID: 20719353 DOI: 10.1016/j.virol.2010.07.042] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 07/18/2010] [Accepted: 07/26/2010] [Indexed: 12/17/2022]
Abstract
Chronic HBV infections cause hepatocellular carcinoma (HCC). Activities of the HBV HBx protein regulate HBV replication and may contribute to the development of HCC. We previously reported that HBx causes primary rat hepatocytes to exit G0 but stall in G1 phase of the cell cycle; entry into G1 stimulated HBV replication. We now report that the activity of the mitochondria permeability transition pore is required for HBx regulation of cell cycle proteins and HBV replication in primary rat hepatocytes, that progression from G0 to G1 stimulates HBV polymerase activity, and that HBV replication is facilitated by the HBx-induced G1 arrest. HBx stimulation of HBV replication was linked to elevation of the R2 subunit of ribonucleotide reductase. Our studies suggest that HBx uses mitochondrial-dependent calcium signaling to cause hepatocytes to exit G0 but stall in G1 and that this HBx activity alters the cellular environment and stimulates HBV replication.
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Affiliation(s)
- Tricia L Gearhart
- Graduate Program in Molecular and Cellular Biology and Genetics, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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50
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Molecular characteristics and functional analysis of full-length hepatitis B virus quasispecies from a patient with chronic hepatitis B virus infection. Virus Res 2010; 150:43-8. [DOI: 10.1016/j.virusres.2010.02.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 02/16/2010] [Accepted: 02/16/2010] [Indexed: 12/15/2022]
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