基因组甲基化抑制乙肝病毒包膜蛋白表达的转基因小鼠

StephenW

PLoS One. 2015 Dec 30;10(12):e0146099. doi: 10.1371/journal.pone.0146099.
Genomic Methylation Inhibits Expression of Hepatitis B Virus Envelope Protein in Transgenic Mice: A Non-Infectious Mouse Model to Study Silencing of HBV Surface Antigen Genes.Graumann F1, Churin Y1, Tschuschner A1, Reifenberg K2, Glebe D3, Roderfeld M1, Roeb E1.
Author information

• 1Department of Gastroenterology, Justus Liebig University, Giessen, Germany.
• 2Central Laboratory Animal Facility, Johannes Gutenberg University, Mainz, Germany.
• 3Institute of Medical Virology, National Reference Centre for Hepatitis B and D Viruses, Justus Liebig University, Giessen, Germany.
  

AbstractOBJECTIVE: The Hepatitis B virus genome persists in the nucleus of virus infected hepatocytes where it serves as template for viral mRNA synthesis. Epigenetic modifications, including methylation of the CpG islands contribute to the regulation of viral gene expression. The present study investigates the effects of spontaneous age dependent loss of hepatitis B surface protein- (HBs) expression due to HBV-genome specific methylation as well as its proximate positive effects in HBs transgenic mice.
METHODS: Liver and serum of HBs transgenic mice aged 5-33 weeks were analyzed by Western blot, immunohistochemistry, serum analysis, PCR, and qRT-PCR.
RESULTS: From the third month of age hepatic loss of HBs was observed in 20% of transgenic mice. The size of HBs-free area and the relative number of animals with these effects increased with age and struck about 55% of animals aged 33 weeks. Loss of HBs-expression was strongly correlated with amelioration of serum parameters ALT and AST. In addition lower HBs-expression went on with decreased ER-stress. The loss of surface protein expression started on transcriptional level and appeared to be regulated epigenetically by DNA methylation. The amount of the HBs-expression correlated negatively with methylation of HBV DNA in the mouse genome.
CONCLUSIONS: Our data suggest that methylation of specific CpG sites controls gene expression even in HBs-transgenic mice with truncated HBV genome. More important, the loss of HBs expression and intracellular aggregation ameliorated cell stress and liver integrity. Thus, targeted modulation of HBs expression may offer new therapeutic approaches. Furthermore, HBs-transgenic mice depict a non-infectious mouse model to study one possible mechanism of HBs gene silencing by hypermethylation.

StephenW

公共科学图书馆之一。 2015年12月30日; 10（12）：e0146099。 DOI：10.1371 / journal.pone.0146099。
基因组甲基化抑制乙肝病毒包膜蛋白表达的转基因小鼠：非感染小鼠模型研究的乙肝病毒表面抗原基因沉默。
Graumann F1，秋林Y1，Tschuschner A1，赖芬贝格K2，旱田D3，Roderfeld M1，Roeb E1。
作者信息

    消化内科教研室，贾斯特斯李比希大学，德国吉森的。
    2Central实验动物设施，约翰内斯·古腾堡大学，美因茨，德国。
    3Institute医学病毒学，国家参考中心B型肝炎和D病毒，贾斯特斯李比希大学，德国吉森。

抽象
目的：

乙肝病毒基因组中仍然存在的病毒感染的肝细胞的细胞核，其中它充当模板用于病毒mRNA的合成。表观遗传修饰，包括CpG岛的甲基化有助于病毒基因表达的调节。本研究探讨的乙肝表面蛋白（HBS）的表达由于HBV基因组的甲基化特异性自发年龄有关的损耗以及在HBS转基因小鼠其靠近正面效应的影响。
方法：

肝脏和血清HBs抗体年龄5-33周的转基因小鼠的免疫印迹法，免疫组织化学，血清分析，PCR和定量RT-PCR分析。
结果：

从第三个月HBs抗体的年龄肝损失的观察在转基因小鼠的20％。对乙型肝炎表面自由区的大小和动物这些效应的相对数量随着年龄的增长和击打约55％年龄33周动物。乙型肝炎表面表达的缺失是密切相关的参数，血清ALT和AST的改善。除了较低的乙型肝炎表面表达继续着降低ER-压力。表面蛋白表达的丧失开始转录水平和似乎是由DNA甲基化表观遗传学调控。乙肝病毒DNA的小鼠基因组的甲基化相关的乙型肝炎表面表达的量负相关。
结论：

我们的数据表明，特定CpG位点的甲基化控制基因表达，即使在HBS-转基因小鼠，被截断的HBV基因组。更重要的是，HBs抗体表达和细胞内聚集的损失改善细胞应激和肝完整性。因此，HBs抗体的表达有针对性的调节可能提​​供新的治疗方法。此外，HBs抗体转基因小鼠描绘一个非感染小鼠模型来研究的HBs抗体基因沉默由高甲基化的一种可能的机制。