乙型肝炎病毒X在体内通过Akt / mTOR途径减少肝细胞凋亡并促进

StephenW

Gene. 2019 Jan 7. pii: S0378-1119(19)30002-2. doi: 10.1016/j.gene.2018.12.054. [Epub ahead of print]
Hepatitis B virus X reduces hepatocyte apoptosis and promotes cell cycle progression through the Akt/mTOR pathway in vivo.
Wang X1, Huo B2, Liu J2, Huang X1, Zhang S2, Feng T3.
Author information

1
    Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China; Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.
2
    Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China; School of Pharmaceutical Science, Chongqing Medical University, Chongqing 400016, China.
3
    Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, China; School of Pharmaceutical Science, Chongqing Medical University, Chongqing 400016, China. Electronic address: [email protected].

Abstract

Hepatitis B virus X (HBx), a viral onco-protein encoded by HBV, can promote oncogenesis of HCC. However, the mechanism of HBx in hepatocarcinogenesis is still unclear. In this study, we establish a new mouse model with normal immune system to investigate the role of HBx and its functional mechanisms under normal immune function. The animal model was established by injecting HBx-EGFP-14-19 cells into the hepatic portal vein of KM mice. To verify the mouse model, the expression of HBx in the liver tissue of mice was detected by qRT-PCR, western blotting and immunohistochemistry. The apoptosis index was calculated using the terminal deoxynucleotidyl transferase-dUTP nick-end labeling (TUNEL) assay, and the expression levels of apoptosis-related and cell cycle-related factors were measured. Moreover, expression of proteins in the protein kinase B/mammalian target of rapamycin (Akt/mTOR) signaling pathway was detected in HBx-EGFP-14-19 mice with and without use of an Akt inhibitor. The results showed the HBx was successfully overexpressed in liver of KM mice. After overexpressing HBx, the apoptosis index was downregulated in HBx-EGFP-14-19 liver tissue, and the expression levels of caspase-9 and Bad were reduced, but Bcl-xl was increased in HBx-EGFP-14-19 liver tissue. Overexpression of HBx increased the expression of the cyclin-dependent kinase 2 (CDK2), cyclinD1 and cyclinE. Moreover, compared with the low-level HBx group, p-Akt and p-mTOR were increased in the livers of mice with high levels of HBx. However, inactivation of apoptosis by overexpression of HBx was abolished by the treatment with an Akt inhibitor. These results indicate that HBx can induce anti-apoptosis mechanisms in hepatocytes in vivo, which is mediated by the Akt/mTOR signaling pathway.

Copyright © 2019 Elsevier Inc. All rights reserved.
KEYWORDS:

Akt/mTOR; Animal model; Apoptosis; Cell cycle; HBx

PMID:
    30630095
DOI:
    10.1016/j.gene.2018.12.054

StephenW

基因。 2019年1月7日.pii：S0378-1119（19）30002-2。 doi：10.1016 / j.gene.2018.12.054。 [提前打印]
乙型肝炎病毒X在体内通过Akt / mTOR途径减少肝细胞凋亡并促进细胞周期进展。
王X1，霍B2，刘J2，黄X1，张S2，冯T3。
作者信息

1
    重庆医科大学分子医学与肿瘤研究中心，重庆400016;重庆医科大学生物化学与分子生物学系，重庆400016
2
    重庆医科大学分子医学与肿瘤研究中心，重庆400016;重庆医科大学药学院，重庆400016
3
    重庆医科大学分子医学与肿瘤研究中心，重庆400016;重庆医科大学药学院，重庆400016电子地址：[email protected]。

抽象

乙型肝炎病毒X（HBx）是一种由HBV编码的病毒癌蛋白，可以促进HCC的肿瘤发生。然而，HBx在肝癌发生中的作用机制尚不清楚。在本研究中，我们建立了一个具有正常免疫系统的新小鼠模型，以研究HBx在正常免疫功能下的作用及其功能机制。通过将HBx-EGFP-14-19细胞注射到KM小鼠的肝门静脉中来建立动物模型。为了验证小鼠模型，通过qRT-PCR，蛋白质印迹和免疫组织化学检测小鼠肝组织中HBx的表达。使用末端脱氧核苷酸转移酶-dUTP缺口末端标记（TUNEL）测定计算凋亡指数，并测量凋亡相关因子和细胞周期相关因子的表达水平。此外，在使用和不使用Akt抑制剂的情况下，在HBx-EGFP-14-19小鼠中检测到蛋白激酶B /雷帕霉素哺乳动物靶标（Akt / mTOR）信号传导途径中蛋白质的表达。结果显示HBx在KM小鼠的肝脏中成功过表达。过量表达HBx后，HBx-EGFP-14-19肝组织细胞凋亡指数下调，caspase-9和Bad表达水平降低，而HBx-EGFP-14-19肝组织中Bcl-xl表达水平升高。过表达HBx可增加细胞周期蛋白依赖性激酶2（CDK2），cyclinD1和cyclinE的表达。此外，与低水平HBx组相比，HB-x水平高的小鼠肝脏中p-Akt和p-mTOR增加。然而，用Akt抑制剂处理消除了过表达HBx导致的细胞凋亡失活。这些结果表明HBx可以在体内诱导肝细胞中的抗凋亡机制，其由Akt / mTOR信号传导途径介导。

版权所有©2019 Elsevier Inc.保留所有权利。
关键词：

AKT / mTOR的;动物模型;细胞凋亡;细胞周期; HBx蛋白

结论：
    30630095
DOI：
    10.1016 / j.gene.2018.12.054