Role of Hepatitis B virus X protein in HBV replication

乙型肝炎病毒X蛋白在HBV复制中的作用

• 批准号: 7037699
• 负责人: Michael J Bouchard
• 金额: $ 33.11万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-01 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7037699
• 关键词: Adenoviridae; apoptosis; calcium flux; calcium indicator; fluorimetry; gene expression; hepatitis B virus group; hepatocellular carcinoma; laboratory rat; liver cells; membrane potentials; mitochondrial membrane; molecular oncology; molecular probes; protein localization; protein protein interaction; protein structure function; thapsigargin; tissue /cell culture; transcription factor; transfection /expression vector; virus protein; virus replication; voltage gated channel; western blottings

DESCRIPTION (provided by applicant): The association between hepatocellular carcinoma (HCC) and chronic infection with the human hepatitis B virus (HBV) has generated considerable interest in understanding how infection with HBV increases the risk for liver cancer. Based on studies in woodchucks infected with the woodchuck hepatitis virus, it is assumed that the X protein (HBx) of all mammalian hepadnaviruses, including human HBV, is essential for viral replication. There is also evidence that HBx contributes to the development of HCC. HBx activates many cellular signaling cascades; however, how this is accomplished is unclear. Most studies that sought to identify the essential role of HBx during HBV replication, and understand how HBx regulates cellular signaling pathways, were performed in liver cell lines derived from liver tumors. The use of immortalized or transformed hepatocytes suffers from its lack of biological relevance compared to authentic hepatocytes. We have demonstrated that a key activity of HBx is regulation of cellular calcium signaling pathways. This proposal aims to understand key activities of HBx using cultures of primary rat hepatocytes and to determine how these activities influence hepatocyte physiology and HBV replication. Studies in AIM 1 will characterize the molecular mechanism of HBx activation of calcium signaling pathways in hepatocytes and how this influences HBV replication. Studies in AIM 2 will focus on the interaction between HBx and mitochondria and how this impacts hepatocyte physiology and HBV replication. AIM 3 specifically focuses on regulation of apoptosis by HBx expressed alone or during HBV replication. Although the fundamental activities of HBx are likely preserved in hepatocytes as compared to transformed cells, the magnitude, duration and complexity of these activities may differ in primary hepatocytes. Results from studies in primary rat hepatocytes should more accurately reflect the state of an authentic infected cell, clarify the disparate HBx activities that have been reported, and provide a more sophisticated understanding of the role of HBx during HBV replication.

描述（由申请人提供）：肝细胞癌（HCC）和慢性感染与人乙型肝炎病毒（HBV）之间的关联引起了人们对了解HBV感染如何增加肝癌风险的极大兴趣。基于对感染木肝炎病毒感染的木木，假定所有哺乳动物肝病病毒（包括人HBV）的X蛋白（HBX）对于病毒复制至关重要。也有证据表明，HBX有助于HCC的发展。 HBX激活许多细胞信号级联。但是，如何实现这一目标尚不清楚。大多数试图识别HBX在HBV复制过程中的基本作用的研究，并了解HBX如何调节细胞信号传导途径，在源自肝肿瘤的肝细胞系中进行。与真实的肝细胞相比，使用永生或转化的肝细胞缺乏生物学相关性。我们已经证明，HBX的关键活性是调节细胞钙信号通路。该建议旨在使用原发性大鼠肝细胞的培养物了解HBX的关键活动，并确定这些活动如何影响肝细胞生理学和HBV复制。 AIM 1中的研究将表征肝细胞中钙信号通路HBX激活的分子机制，以及这如何影响HBV复制。 AIM 2中的研究将集中于HBX和线粒体之间的相互作用，以及这如何影响肝细胞生理和HBV复制。 AIM 3专门针对单独或HBV复制期间的HBX调节凋亡调节。尽管与转化的细胞相比，HBX的基本活性可能保留在肝细胞中，但这些活性的大小，持续时间和复杂性可能在原发性肝细胞中有所不同。原发性大鼠肝细胞的研究的结果应更准确地反映出真实感染细胞的状态，阐明已报告的不同HBX活性，并对HBX复制过程中HBX的作用有更复杂的理解。