Department of Gynecology and Obstetrics, the First Affiliated Hospital of Xi'an Jiaotong University, No. 277, Yanta West Road, Xi'an City, 710061, Shaanxi Province, China.
College of Life Science and Technology, Xi'an Jiaotong University, Xi'an City, China.
Cell Biol Int. 2018 Feb;42(2):237-247. doi: 10.1002/cbin.10891. Epub 2017 Dec 6.
The aim of this study is to investigate the role of Hepatitis B virus x (HBx) in the growth and secretion of human placental trophoblasts. Firstly, placenta tissues were collected from pregnant HBV carriers with various viral loads. The results of immunohistochemical technique showed that the HBx protein and pEGFR protein levels were both markedly increased with the viral load elevation. Then, a placental trophoblast cell strain (JEG-3-HBx), which stably expressed HBx mRNA and protein, was established with the pcDNA-HBx transfection followed by the G418 selection. The JEG-3-HBx strain displayed distinct activation of the EGFR/AKT pathway, a lower level of cell apoptosis, and higher secretion levels of placental hormones, including human chorionic gonadotropin (hCG), progesterone, estrogen and β-endorphin. Subsequently, HBx siRNA was used to silence the HBx gene in the JEG-3-HBx strain. Our data showed that the HBx siRNA transfection markedly suppressed the activation of the EGFR/AKT pathway, promoted cell apoptosis, and reduced the secretion of the placental hormones. Finally, EGF was applied to simulate the JEG-3-HBx strain with or without the HBx siRNA transfection. EGF treatment counteracted the reduction of cell apoptosis and the suppression of hormone secretion caused by HBx siRNA in the cell strain. In conclusion, the pEGFR protein was robustly upregulated in HBx-infected human placenta tissues and trophoblast cells. HBx reduces cell apoptosis and promotes the secretion of placental hormones in human placental trophoblast cells via activation of the EGFR/Akt pathway.
本研究旨在探讨乙型肝炎病毒 x（HBx）在人胎盘滋养层生长和分泌中的作用。首先，收集了来自不同病毒载量的 HBV 携带者的胎盘组织。免疫组化技术的结果显示，HBx 蛋白和 pEGFR 蛋白水平均随病毒载量的升高而显著增加。然后，通过 pcDNA-HBx 转染和 G418 选择，建立了稳定表达 HBx mRNA 和蛋白的胎盘滋养层细胞株（JEG-3-HBx）。JEG-3-HBx 株表现出明显的 EGFR/AKT 通路激活、细胞凋亡水平降低和胎盘激素（包括人绒毛膜促性腺激素（hCG）、孕酮、雌激素和β-内啡肽）分泌水平升高。随后，用 HBx siRNA 沉默 JEG-3-HBx 株中的 HBx 基因。我们的数据显示，HBx siRNA 转染显著抑制了 EGFR/AKT 通路的激活，促进了细胞凋亡，并减少了胎盘激素的分泌。最后，应用 EGF 模拟有无 HBx siRNA 转染的 JEG-3-HBx 株。EGF 处理逆转了 HBx siRNA 转染对细胞株中细胞凋亡减少和激素分泌抑制的作用。总之，HBx 感染的人胎盘组织和滋养层细胞中 pEGFR 蛋白显著上调。HBx 通过激活 EGFR/Akt 通路减少人胎盘滋养层细胞的细胞凋亡并促进胎盘激素的分泌。
