Department of Infectious Diseases, Xiangya Hospital, Central South University, No.87, Xiangya Road, Kaifu District, Changsha, 410008, Hunan, China.
Department of Infectious Diseases, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China.
J Biomed Sci. 2021 Oct 6;28(1):67. doi: 10.1186/s12929-021-00762-2.
Acute liver failure (ALF) is a syndrome of severe hepatocyte injury with high rate of mortality. Hepatitis B virus (HBV) infection is the major cause of ALF worldwide, however, the underlying mechanism by which HBV infection leads to ALF has not been fully disclosed.
D-GalN-induced hepatocyte injury model and LPS/D-GalN-induced ALF mice model were used to investigate the effects of HBV X protein (HBx) in vitro and in vivo, respectively. Cell viability and the levels of Glutathione (GSH), malondialdehyde (MDA) and iron were measured using commercial kits. The expression of ferroptosis-related molecules were detected by qRT-PCR and western blotting. Epigenetic modification and protein interaction were detected by chromatin immunoprecipitation (ChIP) assay and co-immunoprecipitation (co-IP), respectively. Mouse liver function was assessed by measuring aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The histological changes in liver tissues were monitored by hematoxylin and eosin (H&E) staining, and SLC7A11 immunoreactivity was assessed by immunohistochemistry (IHC) analysis.
D-GalN triggered ferroptosis in primary hepatocytes. HBx potentiated D-GalN-induced hepatotoxicity and ferroptosis in vitro, and it suppressed SLC7A11 expression through H3K27me3 modification by EZH2. In addition, EZH2 inhibition or SLC7A11 overexpression attenuated the effects of HBx on D-GalN-induced ferroptosis in primary hepatocytes. The ferroptosis inhibitor ferrostatin-1 (Fer-1) protected against ALF and ferroptosis in vivo. By contrast, HBx exacerbates LPS/D-GalN-induced ALF and ferroptosis in HBx transgenic (HBx-Tg) mice.
HBx facilitates ferroptosis in ALF via EZH2/H3K27me3-mediated SLC7A11 suppression.
急性肝衰竭（ALF）是一种严重的肝细胞损伤综合征，死亡率很高。乙型肝炎病毒（HBV）感染是全球 ALF 的主要原因，但 HBV 感染导致 ALF 的潜在机制尚未完全揭示。
使用 D-半乳糖胺（D-GalN）诱导的肝细胞损伤模型和脂多糖（LPS）/D-GalN 诱导的 ALF 小鼠模型，分别在体外和体内研究 HBV X 蛋白（HBx）的作用。使用商业试剂盒测量细胞活力以及谷胱甘肽（GSH）、丙二醛（MDA）和铁的水平。通过 qRT-PCR 和 Western blot 检测铁死亡相关分子的表达。通过染色质免疫沉淀（ChIP）测定和共免疫沉淀（co-IP）分别检测表观遗传修饰和蛋白质相互作用。通过测量天冬氨酸氨基转移酶（AST）和丙氨酸氨基转移酶（ALT）来评估小鼠的肝功能。通过苏木精和伊红（H&E）染色监测肝组织的组织学变化，并通过免疫组化（IHC）分析评估 SLC7A11 免疫反应性。
D-GalN 引发原代肝细胞发生铁死亡。HBx 增强了 D-GalN 诱导的体外肝细胞毒性和铁死亡，并通过 EZH2 对 SLC7A11 表达进行 H3K27me3 修饰来抑制其表达。此外，EZH2 抑制或 SLC7A11 过表达可减轻 HBx 对 D-GalN 诱导的原代肝细胞铁死亡的影响。铁死亡抑制剂 Fer-1 在体内可防止 ALF 和铁死亡。相反，HBx 加剧了 HBx 转基因（HBx-Tg）小鼠的 LPS/D-GalN 诱导的 ALF 和铁死亡。
HBx 通过 EZH2/H3K27me3 介导的 SLC7A11 抑制促进 ALF 中的铁死亡。
