keyword
MENU ▼
Read by QxMD icon Read
search

cccDNA

keyword
https://www.readbyqxmd.com/read/28297795/-the-potential-use-of-serum-hbv-rna-to-guide-the-functional-cure-of-chronic-hepatitis-b
#1
F M Lu, J Wang, X M Chen, J N Jiang, W H Zhang, J M Zhao, H Ren, J L Hou, N S Xia
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in infected hepatocytes is the main cause of off-therapy viral rebound. The half-life of cccDNA is only 33-50 days, so the conversion of newly synthesized rcDNA to cccDNA in the nucleus is essential for the maintenance of cccDNA pool in infected hepatocytes. Though not directly targeting the existing cccDNA, current nucleos(t)ide analogues (NAs) may exhaust the cccDNA reservoir by blocking the rcDNA formation. Indeed, a prolonged consolidation therapy post loss of serum HBV DNA can achieve sustained remission and thus safe drug discontinuation in a small proportion of chronic hepatitis B (CHB) patients...
February 20, 2017: Zhonghua Gan Zang Bing za Zhi, Zhonghua Ganzangbing Zazhi, Chinese Journal of Hepatology
https://www.readbyqxmd.com/read/28286056/detection-of-hbv-dna-and-antigens-in-hbsag-positive-patients-with-primary-hepatocellular-carcinoma
#2
Sha Fu, Ning Li, Peng-Cheng Zhou, Yan Huang, Rong-Rong Zhou, Xue-Gong Fan
BACKGROUND: Hepatitis B virus (HBV) markers include HBV deoxyribonucleic acid (DNA) and HBV antigens. The former involves HBV covalently closed circular DNA (cccDNA) as well as total HBV DNA, whereas the latter involves HBsAg, HBcAg, and HBx. METHODS: Samples of tumor and adjacent non-tumor liver tissue were collected from 28 HBV-associated HCC patients. Intrahepatic total HBV DNA and cccDNA were measured using the real-time PCR Taqman assay. HBV antigens in hepatocytes were detected using immunohistochemical staining...
March 9, 2017: Clinics and Research in Hepatology and Gastroenterology
https://www.readbyqxmd.com/read/28282964/serum-hepatitis-b-core-related-antigen-is-a-satisfactory-surrogate-marker-of-intrahepatic-covalently-closed-circular-dna-in-chronic-hepatitis-b
#3
En-Qiang Chen, Shu Feng, Meng-Lan Wang, Ling-Bo Liang, Ling-Yun Zhou, Ling-Yao Du, Li-Bo Yan, Chuan-Min Tao, Hong Tang
Recently, hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. This study aimed to investigate whether serum quantitative HBcrAg (qHBcrAg) was a satisfactory surrogate marker of intrahepatic covalently closed circular DNA (cccDNA). A total of 139 patients with liver biopsy were enrolled, consisting of 59 patients in immune tolerance (IT) phase, 52 patients in immune clearance (IC) phase, 18 patients in low-replication (LR) phase, and 10 patients in reactivation phase...
December 2017: Scientific Reports
https://www.readbyqxmd.com/read/28275452/advancing-the-regulatory-path-on-hepatitis-b-virus-treatment-and-curative-research-a-stakeholders-consultation
#4
EDITORIAL
Jonathan Liu, Pedro Goicochea, Timothy Block, Carol L Brosgart, Eric F Donaldson, Oliver Lenz, Seng Gee Lim, Ed G Marins, Poonam Mishra, Marion G Peters, Veronica Miller
Hepatitis B infection remains a significant disease burden around the world, with an estimated two billion individuals infected and 350 million living with chronic hepatitis B. Current antivirals are efficacious, but require lifelong treatment for the majority of infected individuals. The field is galvanised to improve diagnostics and treatment with the goal to develop shorter, finite treatments leading to viral control after treatment discontinuation. Achievement of complete and functional cure is challenged by the complexity of the virus life cycle, the lack of adequate preclinical models, the cccDNA-mediated persistence of HBV in liver cells, the lack of validated biomarkers to predict viral control and cure, and the probable need for combination treatment involving antiviral- and immune-based strategies...
January 1, 2017: Journal of Virus Eradication
https://www.readbyqxmd.com/read/28242208/interplay-between-sirt1-and-hepatitis-b-virus-x-protein-in-the-activation-of-viral-transcription
#5
Jian-Jun Deng, Ka-Yiu Edwin Kong, Wei-Wei Gao, Hei-Man Vincent Tang, Vidyanath Chaudhary, Yun Cheng, Jie Zhou, Chi-Ping Chan, Danny Ka-Ho Wong, Man-Fung Yuen, Dong-Yan Jin
Hepatitis B virus (HBV) genome is organized into a minichromosome known as covalently closed circular DNA (cccDNA), which serves as the template for all viral transcripts. SIRT1 is an NAD(+)-dependent protein deacetylase which activates HBV transcription by promoting the activity of cellular transcription factors and coactivators. How SIRT1 and viral transactivator X protein (HBx) might affect each other remains to be clarified. In this study we show synergy and mutual dependence between SIRT1 and HBx in the activation of HBV transcription...
February 24, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28236308/prmt5-restricts-hepatitis-b-virus-replication-via-epigenetic-repression-of-cccdna-transcription-and-interference-with-pgrna-encapsidation
#6
Wen Zhang, Jieliang Chen, Min Wu, Xiaonan Zhang, Min Zhang, Lei Yue, Yaming Li, Jiangxia Liu, Baocun Li, Fang Shen, Yang Wang, Lu Bai, Ulrike Protzer, Massimo Levrero, Zhenghong Yuan
Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. The covalently closed circular DNA (cccDNA) minichromosome, which serves as the template for the transcription of viral RNAs, plays a key role in viral persistence. While accumulating evidence suggests that cccDNA transcription is regulated by epigenetic machinery, particularly the acetylation of cccDNA-bound histone 3 (H3) and H4, the potential contributions of histone methylation and related host factors remain obscured. Here, by screening a series of methyltransferases and demethylases, we identified protein arginine methyltransferase 5 (PRMT5) as an effective restrictor of HBV transcription and replication...
February 25, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/28213165/hbvcircle-a-novel-tool-to-investigate-hepatitis-b-virus-covalently-closed-circular-dna
#7
Zhipeng Yan, Jing Zeng, Youjun Yu, Kunlun Xiang, Hui Hu, Xue Zhou, Lili Gu, Li Wang, Jie Zhao, John A T Young, Lu Gao
BACKGROUND & AIMS: Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) persists as a stable episome in infected hepatocytes and serves as a template for the transcription of all viral genes. Due to the narrow host range of HBV, the development of a robust mouse model that supports cccDNA-dependent viral replication is a key hurdle in the development of novel HBV therapeutics. This study aimed to develop a novel tool to investigate HBV cccDNA. METHODS: Through minicircle technology, HBVcircle, a recombinant cccDNA, was easily generated and extracted from a genetically engineered E...
February 14, 2017: Journal of Hepatology
https://www.readbyqxmd.com/read/28212627/genome-wide-identification-of-direct-hbx-genomic-targets
#8
Francesca Guerrieri, Laura Belloni, Daniel D'Andrea, Natalia Pediconi, Loredana Le Pera, Barbara Testoni, Cecilia Scisciani, Oceane Floriot, Fabien Zoulim, Anna Tramontano, Massimo Levrero
BACKGROUND: The Hepatitis B Virus (HBV) HBx regulatory protein is required for HBV replication and involved in HBV-related carcinogenesis. HBx interacts with chromatin modifying enzymes and transcription factors to modulate histone post-translational modifications and to regulate viral cccDNA transcription and cellular gene expression. Aiming to identify genes and non-coding RNAs (ncRNAs) directly targeted by HBx, we performed a chromatin immunoprecipitation sequencing (ChIP-Seq) to analyse HBV recruitment on host cell chromatin in cells replicating HBV...
February 17, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28195359/sodium-taurocholate-cotransporting-polypeptide-is-the-limiting-host-factor-of-hepatitis-b-virus-infection-in-macaque-and-pig-hepatocytes
#9
Florian A Lempp, Ellen Wiedtke, Bingqian Qu, Pierre Roques, Isabelle Chemin, Florian W R Vondran, Roger Le Grand, Dirk Grimm, Stephan Urban
Infections with the human Hepatitis B (HBV) and Hepatitis D Virus (HDV) depend on species-specific host factors like the receptor human sodium taurocholate cotransporting polypeptide hNTCP. Complementation of mouse hepatocytes with hNTCP confers susceptibility to HDV but not HBV indicating the requirement of additional HBV-specific factors. As an essential premise towards the establishment for an HBV-susceptible animal model, we investigated the role of hNTCP as a limiting factor of hepatocytes in commonly used laboratory animals...
February 13, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/28182305/hepatitis-b-virus-covalently-closed-circular-dna-homeostasis-is-independent-of-the-lymphotoxin-pathway-during-chronic-hbv-infection
#10
Marie-Anne Meier, Aleksei Suslov, Sylvia Ketterer, Markus H Heim, Stefan F Wieland
Current treatment options for patients with chronic hepatitis B virus (HBV) infection are not curative as they are not effective in eliminating covalently closed circular DNA (cccDNA). cccDNA is a stable template for HBV transcription in the nucleus of hepatocytes and is thought to be one of the main factors responsible for HBV persistence. Recently, activation of the lymphotoxin beta receptor (LTβR) has been shown to trigger degradation of cccDNA through induction of cytidine deaminases of the APOBEC3 family in HBV cell culture model systems...
February 9, 2017: Journal of Viral Hepatitis
https://www.readbyqxmd.com/read/28121714/hepatitis-delta-and-hiv-infection
#11
Vincent Soriano, Kenneth E Sherman, Pablo Barreiro
Viral liver diseases are frequent co-morbidities and major contributors to death in HIV-positive individuals on antiretroviral therapy. Whereas cure of hepatitis C and control of hepatitis B with antivirals avert liver disease progression in most HIV-coinfected patients, the lack of satisfactory treatment for hepatitis delta virus (HDV) infection remains a major threat for developing cirrhosis and liver cancer in this population. In the European Union and North America, sexual contact has replaced injection drug use has major transmission route for HDV in HIV-positive persons...
January 24, 2017: AIDS
https://www.readbyqxmd.com/read/28095508/the-smc5-6-complex-restricts-hbv-when-localized-to-nd10-without-inducing-an-innate-immune-response-and-is-counteracted-by-the-hbv-x-protein-shortly-after-infection
#12
Congrong Niu, Christine M Livingston, Li Li, Rudolf K Beran, Stephane Daffis, Dhivya Ramakrishnan, Dara Burdette, Leanne Peiser, Eduardo Salas, Hilario Ramos, Mei Yu, Guofeng Cheng, Michel Strubin, William E Delaney Iv, Simon P Fletcher
The structural maintenance of chromosome 5/6 complex (Smc5/6) is a restriction factor that represses hepatitis B virus (HBV) transcription. HBV counters this restriction by expressing HBV X protein (HBx), which targets Smc5/6 for degradation. However, the mechanism by which Smc5/6 suppresses HBV transcription and how HBx is initially expressed is not known. In this study we characterized viral kinetics and the host response during HBV infection of primary human hepatocytes (PHH) to address these unresolved questions...
2017: PloS One
https://www.readbyqxmd.com/read/28087399/advances-with-using-crispr-cas-mediated-gene-editing-to-treat-infections-with-hepatitis-b-virus-and-hepatitis-c-virus
#13
REVIEW
Buhle Moyo, Kristie Bloom, Tristan Scott, Abdullah Ely, Patrick Arbuthnot
Chronic infections with hepatitis B and hepatitis C viruses (HBV and HCV) account for the majority of cases of cirrhosis and hepatocellular carcinoma. Current therapies for the infections have limitations and improved efficacy is necessary to prevent complications in carriers of the viruses. In the case of HBV persistence, the replication intermediate comprising covalently closed circular DNA (cccDNA) is particularly problematic. Licensed therapies have little effect on cccDNA and HBV replication relapses following treatment withdrawal...
January 10, 2017: Virus Research
https://www.readbyqxmd.com/read/28052637/future-anti-hbv-strategies
#14
REVIEW
Edward J Gane
Although current oral antivirals can maintain viral suppression and reduce the risk of liver-related complications, lifelong therapy is associated with high cost, risk of breakthrough and potential toxicity. There is a need to develop a finite course of treatment which can provide sustained off-treatment virological and clinical response. The likely marker of such a clinical HBV CURE would be HBsAg clearance, but in addition cccDNA elimination would be required to prevent future reactivation (ie complete HBV cure)...
January 2017: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/28052622/novel-targets-for-hepatitis-b-virus-therapy
#15
REVIEW
Barbara Testoni, David Durantel, Fabien Zoulim
Treatment with either pegylated interferon-alpha (pegIFN-α) or last generation nucleos(t)ide analogues (NAs) successfully leads to serum viral load suppression in most chronically infected hepatitis B (CHB) patients, but HBsAg loss is only achieved in 10% of the cases after a 5-year follow-up. Thus, therapy must be administered long-term and it will not completely eliminate infection because of the persistent hepatitis B virus (HBV) minichromosome in infected cells, and cannot completely abolish the risk of developing severe sequelae such as cirrhosis and hepatocellular carcinoma...
January 2017: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/27998270/pcr-mediated-recombination-impacts-the-analysis-of-hepatitis-b-virus-covalently-closed-circular-dna
#16
Rodolphe Suspène, Valérie Thiers, Jean-Pierre Vartanian, Simon Wain-Hobson
BACKGROUND: The replication of HBV involves the production of covalently closed circular DNA (cccDNA) from the HBV genome through the repair of virion relaxed circular DNA (rcDNA) in the virion. As cccDNA is the transcription template for HBV genomes, it needs to be eliminated from hepatocytes if the eradication of chronic HBV infection is to be achieved. PCR quantitation of cccDNA copy number is the technique of choice for evaluating the efficiency of treatment regimens. The PCR target commonly used to identify cccDNA spans the gapped region of rcDNA and is considered to accurately distinguish between cccDNA and rcDNA...
December 20, 2016: Retrovirology
https://www.readbyqxmd.com/read/27992681/hepatitis-b-virus-core-related-antigen-as-a-surrogate-marker-for-covalently-closed-circular-dna
#17
Danny Ka-Ho Wong, Wai-Kay Seto, Ka-Shing Cheung, Chun-Kong Chong, Fung-Yu Huang, James Fung, Ching-Lung Lai, Man-Fung Yuen
BACKGROUND & AIMS: Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is a key to viral persistence in chronic hepatitis B infection. Serum hepatitis B core-related antigen (HBcrAg) is a novel marker for HBV disease. We aimed to determine whether HBcrAg could be a surrogate marker for intrahepatic cccDNA. METHODS: Three hundred and five liver biopsies and the corresponding sera collected from 138 nucleos(t)ide analogues-treated patients were analysed...
December 19, 2016: Liver International: Official Journal of the International Association for the Study of the Liver
https://www.readbyqxmd.com/read/27978466/metabolite-identification-of-bentysrepinine-y101-a-novel-anti-hbv-agent-in-rats-using-a-five-step-strategy-based-on-a-combined-workflow-with-two-different-platforms-of-liquid-chromatography-tandem-mass-spectrometry
#18
Huirong Fan, Zhanxing Hu, Ruixing Li, Shiqi Dong, Yuan Gu, Ting Liu, Duanyun Si, Guangyi Liang, Changxiao Liu
Bentysrepinine (Y101), a derivative of repensine (a compound isolated from Dichondrarepens Forst), is a novel phenyalanine dipeptide inhibiting DNA-HBV and cccDNA activities and is currently under development for the treatment of hepatitis B virus (HBV)-infected hepatitis. Our previous study implied that there might be an existence of extensive metabolism of Y101 in rats. Therefore, it is necessary to perform metabolic profiling study to further evaluate its safety and drug-like properties. In this study, the metabolism of Y101 in rats was investigated by a convincible five-step strategy to characterize metabolites in plasma and that excreted into urine, bile and feces...
January 1, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/27975313/immunofluorescent-staining-for-the-detection-of-the-hepatitis-b-core-antigen-in-frozen-liver-sections-of-human-liver-chimeric-mice
#19
Lena Allweiss, Marc Lütgehetmann, Maura Dandri
The hepatitis B virus (HBV) is the causative agent for chronic hepatitis B infection, which affects an estimate of 240 million people worldwide and puts them at risk of developing terminal liver disease. The life cycle of the virus and its interactions with the host immune system are still incompletely understood, and currently available treatment options rarely achieve a cure. Therefore, basic research and new drug development are needed. One parameter for measuring the intrahepatic activity of the virus is monitoring the production of the HBV core antigen (HBcAg), which not only serves as the main structural protein of its nucleocapsid but is also recruited to the covalently closed circular DNA (cccDNA), the nuclear HBV genome responsible for infection persistence...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27975310/a-t7-endonuclease-i-assay-to-detect-talen-mediated-targeted-mutation-of-hbv-cccdna
#20
Kristie Bloom, Abdullah Ely, Patrick Arbuthnot
Gene editing using designer nucleases is now widely used in many fields of molecular biology. The technology is being developed for the treatment of viral infections such as persistant hepatitis B virus (HBV). The replication intermediate of HBV comprising covalently closed circular DNA (cccDNA) is stable and resistant to available licensed antiviral agents. Advancing gene editing as a means of introducing targeted mutations into cccDNA thus potentially offers the means to cure infection by the virus. Essentially, targeted mutations are initiated by intracellular DNA cleavage, then error-prone nonhomologous end joining results in insertions and deletions (indels) at intended sites...
2017: Methods in Molecular Biology
keyword
keyword
31570
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"