当前位置: X-MOL 学术J. Hepatol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Identification of Slug and Sox7 as transcriptional repressors binding to the Hepatitis B Virus Core Promoter
Journal of Hepatology ( IF 26.8 ) Pub Date : 2018-01-01 , DOI: 10.1016/j.jhep.2017.08.033
Hui Ling Ko 1 , Tze Hau Lam 1 , Huijin Ng 2 , Jiaying Toh 3 , Liang Wei Wang 4 , Ee Chee Ren 5
Affiliation  

BACKGROUND & AIMS The Hepatitis B Virus (HBV) may gain entry into non-liver cells but does not actively replicate in them. We investigated the possibility that these cells possess mechanisms that block HBV core promoter (HBVCP) transcription, specifically absent in liver cells, which together with other liver-specific mechanisms, such as sodium-taurocholate cotransporting polypeptide-mediated entry, enable liver cells to effectively produce HBV. METHODS Liver and non-liver cell lines were screened for their capacity to activate the HBVCP and synthesize pre-genomic RNA (pgRNA). Transcription regulators differentially expressed between cells with active or inactive HBVCP were determined by human transcriptome array. Slug (SNAI2) and SRY-related HMG box 7 (SOX7) transcriptional repressors were identified and shown to bind specifically to the HBVCP by electrophoretic mobility shift assay. The resultant inhibitory effect on HBVCP transcription was validated using luciferase reporter and assays for pgRNA, HBcAg and cccDNA accumulation in cells with HBV replicon and HBV infection models. To further confirm their specific activity, short peptide mimetics generated from Slug zinc-finger domains and SOX7 HMG-box were generated. RESULTS The HBVCP was found to be active in liver and selected non-liver cells. These cells have low/negligible expression of Slug and SOX7, which inhibit HBVCP transcription specifically by binding at the pgRNA initiator site and competitively displacing hepatocyte nuclear factor 4α, respectively. Overexpression of Slug and/or SOX7 specifically reduced HBVCP transcription, significantly diminishing pgRNA synthesis, HBcAg and cccDNA accumulation in HBV-infected primary human hepatocytes. Similar results were obtained with Slug and SOX7 stapled peptides individually, which were even more potent in combination. CONCLUSIONS Slug and SOX7 are transcriptional repressors that bind specifically to the HBVCP. Their absence or weak expression in liver cells contribute to the favorable host environment for the active and efficient production of HBV. LAY SUMMARY Hepatitis B virus (HBV) replication occurs efficiently in human liver because of the specificity of viral uptake receptors and presence of numerous liver-enriched transcription activators. Herein, we show that the specific lack of transcriptional inhibitory mechanisms in liver cells also contribute to effective HBV production. HBV replication is kept low in non-liver cells as transcriptional repressors Slug and SRY-related HMG box 7 (SOX7) actively bind to the transcriptional initiator and displace transcription activators, respectively, within the HBV core promoter.

中文翻译:


鉴定 Slug 和 Sox7 作为与乙型肝炎病毒核心启动子结合的转录抑制子



背景与目的 乙型肝炎病毒 (HBV) 可能会进入非肝细胞,但不会在其中主动复制。我们研究了这些细胞是否具有阻断 HBV 核心启动子 (HBVCP) 转录的机制,尤其是肝细胞中不存在的机制,该机制与其他肝脏特异性机制(例如牛磺胆酸钠共转运多肽介导的进入)一起,使肝细胞能够有效地产生乙肝病毒。方法 筛选肝细胞和非肝细胞系激活 HBVCP 和合成前基因组 RNA (pgRNA) 的能力。通过人类转录组阵列确定具有活性或非活性 HBVCP 的细胞之间差异表达的转录调节因子。 Slug (SNAI2) 和 SRY 相关的 HMG box 7 (SOX7) 转录抑制因子被鉴定出来,并通过电泳迁移率变动测定显示其与 HBVCP 特异性结合。使用荧光素酶报告基因以及 HBV 复制子和 HBV 感染模型细胞中 pgRNA、HBcAg 和 cccDNA 积累的测定,验证了由此产生的对 HBVCP 转录的抑制作用。为了进一步确认它们的特异性活性,从 Slug 锌指结构域和 SOX7 HMG-box 生成了短肽模拟物。结果发现 HBVCP 在肝脏和选定的非肝细胞中具有活性。这些细胞具有低/可忽略的 Slug 和 SOX7 表达,它们分别通过在 pgRNA 起始位点结合并竞争性取代肝细胞核因子 4α 来特异性抑制 HBVCP 转录。 Slug 和/或 SOX7 的过表达特异性降低 HBVCP 转录,显着减少 HBV 感染的原代人肝细胞中的 pgRNA 合成、HBcAg 和 cccDNA 积累。 单独使用 Slug 和 SOX7 钉合肽也获得了类似的结果,组合使用时效果更佳。结论 Slug 和 SOX7 是与 HBVCP 特异性结合的转录抑制因子。它们在肝细胞中的缺失或弱表达有助于为 HBV 的活跃和高效产生提供有利的宿主环境。摘要 由于病毒摄取受体的特异性以及大量肝脏富集的转录激活剂的存在,乙型肝炎病毒 (HBV) 复制在人类肝脏中有效发生。在此,我们发现肝细胞中转录抑制机制的特定缺乏也有助于乙肝病毒的有效产生。 HBV 复制在非肝细胞中保持较低水平,因为转录抑制因子 Slug 和 SRY 相关的 HMG box 7 (SOX7) 分别主动结合 HBV 核心启动子内的转录起始子并取代转录激活子。
更新日期:2018-01-01
down
wechat
bug