Developmental regulation of HBV biosynthesis by FoxA and DNA methylation

FoxA 和 DNA 甲基化对 HBV 生物合成的发育调控

基本信息

批准号：
9275362
负责人：
Alan McLachlan
金额：
$ 39.98万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-18 至 2021-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9275362
关键词：
Acute Adult Alleles Anabolism Animal Model Antiviral Therapy Capsid Cessation of life Chromatin Structure Chronic Chronic Hepatitis B Circular DNA Clinical DNA DNA Methylation DNA sequencing Development Doxycycline Embryo Epigenetic Process Family Gene Expression Gene Silencing Genes Genetic Genetic Transcription Genome Genomic DNA Health Hepatic Hepatitis B Hepatocyte Histones Human Hypermethylation Individual Lead Life Cycle Stages Liver Methylation Modality Molecular Molecular Weight Nature Nuclear Nucleotides Phenotype Physiology Play Proteins RNA Regulation Resolution Reverse Transcription Role Signal Transduction System Transcription Factor 3 Transgenes Transgenic Mice Viral Viral Genome Viral Load result Virus Diseases Virus Inactivation bisulfite cellular targeting chronic liver disease design effective therapy hepatocyte nuclear factor in vivo liver development liver function methylation pattern mouse model new therapeutic target novel novel strategies pathogen postnatal prevent targeted treatment therapeutic target transcription factor viral DNA

项目摘要

Hepatitis B virus (HBV) infection is a worldwide health problem. It is estimated that there are 200 to 500 million HBV chronic carriers in the world for whom, to date, there is no reliable treatment. HBV causes both acute and chronic liver disease and is responsible for an estimated one million deaths annually. Currently available therapies reduce viral loads but fail to resolve chronic HBV infections. Therefore, effective treatments for chronic HBV infection are urgently required. The major obstacle to the resolution of chronic HBV infections is the eradication or inactivation of nuclear HBV covalently closed circular (CCC) DNA which is the template for viral transcription. To this end, we have developed HNF1α-null HBV transgenic mice and liver-specific FoxA/HNF3-deficient HBV transgenic mice. HNF1α-null HBV transgenic mice synthesize nuclear HBV CCC DNA. Liver-specific FoxA/HNF3-deficient HBV transgenic mice are viable but lack detectable HBV transcription and replication (i.e. they are effectively “cured”) suggesting FoxA/HNF3 not only plays an important developmental role in the hepatocyte-specific transcription factor network governing the hepatic phenotype but is also essential for viral biosynthesis. The observation that FoxA/HNF3-deficient HBV transgenic mice display hyper-methylation of HBV genomic DNA suggests that FoxA/HNF3 is epigenetically governing HBV transcription by modulating viral chromatin structure in vivo and hence determines the level of viral biosynthesis. Defining the precise temporal requirements for FoxA/HNF3 expression associated with HBV transcription and replication will indicate the liver developmental stages when viral biosynthesis is susceptible to inhibition by FoxA/HNF3 deficiency. This will be achieved by modulating FoxA/HNF3 expression in the FoxA/HNF3-deficient HBV transgenic mouse model using the TET/OFF system. Using this system, the developmental control of HBV transcription, viral biosynthesis and HBV DNA methylation by FoxA/HNF3 expression will be established and correlated with the epigenetic histone marks and chromatin structure associated with the HBV genome. Finally, similar studies will be performed using the HNF1α-null FoxA/HNF3-deficient HBV transgenic mouse model of chronic viral infection so the developmental control of HBV transcription, viral biosynthesis, HBV DNA methylation, epigenetic histone marks and chromatin structure by FoxA/HNF3 expression associated with the HBV genome can be compared between the HBV transgene DNA and the nuclear HBV CCC DNA. Defining the nature of the changes and the molecular signals responsible for the loss of HBV biosynthesis due to FoxA/HNF3 deficiency may lead to the identification of cellular therapeutic targets that are amenable to the development of novel modalities to resolve rather than simply treat chronic HBV infection.

乙型肝炎病毒 (HBV) 感染是一个全球性的健康问题，据估计，世界上有 200 至 5 亿乙型肝炎病毒慢性携带者，迄今为止，乙型肝炎病毒尚无可靠的治疗方法，可导致急性和慢性肝病。据估计，每年有 100 万人死亡。目前可用的治疗方法可减少病毒载量，但无法解决慢性 HBV 感染，因此迫切需要有效治疗慢性 HBV 感染，解决慢性 HBV 感染的主要障碍是根除。为此，我们开发了 HNF1α 缺失的 HBV 转基因小鼠和肝脏特异性 FoxA/HNF3 缺陷的 HBV HNF1α 转基因小鼠。转基因小鼠合成核 HBV CCC DNA 肝脏特异性 FoxA/HNF3 缺陷的 HBV 转基因小鼠可以存活，但缺乏可检测的 HBV 转录和复制（即FoxA/HNF3 缺陷的 HBV 转基因小鼠表现出的观察结果表明，FoxA/HNF3 不仅在控制肝脏表型的肝细胞特异性转录因子网络中发挥着重要的发育作用，而且对于病毒生物合成也至关重要。 HBV 基因组 DNA 的高甲基化表明 FoxA/HNF3 通过在体内调节病毒染色质结构来表观遗传地控制 HBV 转录，从而决定病毒生物合成的水平。定义与 HBV 转录和复制相关的 FoxA/HNF3 表达的精确时间要求将表明病毒生物合成容易受到 FoxA/HNF3 缺陷抑制的肝脏发育阶段，这将通过调节 FoxA/HNF3 中的 FoxA/HNF3 表达来实现。 -使用TET/OFF系统的缺陷HBV转基因小鼠模型使用该系统，通过控制HBV转录、病毒生物合成和HBV DNA甲基化。 FoxA/HNF3 表达将被建立，并与与 HBV 基因组相关的表观遗传组蛋白标记和染色质结构相关联。最后，将使用 HNF1α 缺失的 FoxA/HNF3 缺陷的慢性病毒感染 HBV 转基因小鼠模型进行类似的研究。可以比较与 HBV 基因组相关的 FoxA/HNF3 表达对 HBV 转录、病毒生物合成、HBV DNA 甲基化、表观遗传组蛋白标记和染色质结构的发育控制确定 HBV 转基因 DNA 和核 HBV CCC DNA 之间变化的性质以及导致 FoxA/HNF3 缺陷导致 HBV 生物合成丧失的分子信号可能有助于识别适合开发的细胞治疗靶点。解决而不是简单地治疗慢性乙型肝炎感染的新方法。