登革病毒及其E蛋白和NS3蛋白对HepG2细胞中GSH水平的影响

GSH changes in HepG2 cells infected by dengue virus or stably expressing viral protein E and NS3

目的通过对登革病毒感染后不同时相点以及稳定表达登革病毒E蛋白和NS3蛋白的HepG2细胞中GSH水平的测定,确定登革病毒感染后细胞内GSH水平的变化规律,以及登革病毒蛋白的表达对HepG2细胞内GSH水平的影响。方法用分光光度计比色定量检测登革病毒2型感染后不同时相点以及稳定表达登革病毒E蛋白和NS3蛋白的HepG2细胞中GSH水平的变化。结果总体来说,登革病毒2型感染后48h内,HepG2细胞内GSH的水平呈下降趋势,其中以感染后的30min、2h和24h细胞内GSH变化最为明显,与模拟感染组和其他时相点比较,均有显著差异;而稳定表达登革病毒E蛋白和NS3蛋白的HepG2细胞内GSH的水平也均较空质粒对照组降低。结论登革病毒2型感染HepG2细胞,可使细胞内的GSH下降,且呈现阶段性,推测可能与病毒的吸附、穿入、蛋白质合成、释放等过程有关,且登革病毒E蛋白和NS3蛋白在细胞内的表达也能一定程度地降低其GSH水平。

Objective To investigate the changes of intracellular GSH content in HepG2 cells infected with dengue virus （DV） or stably expressing E or NS3 protein. Methods HepG2 cells were cocultured with DV or inactivitated DV, 1 h later the viral supernatant was removed. The infected HepG2 cells were collected 10, 20, 30, 40, 60 min, and 2, 6, 12, 24, 48 h after the beginning coculture and intracellular GSH content was detected by spectrophotometry. Intracellular GSH content was also detected in HepG2 cells stably expressing E protein/NS3 （pReceiver-E/HepG2, pReceiver-NS3/HepG2） and those containing empty plasmid （pReceiver/HepG2）. Results GSH content showed a decreasing tendency after DV-2 infection. The lowest values were seen 30 min and 2, 24 h after infection, which were of significant difference in comparison with those in inactivated DV infected HepG2 cells as well as at other time points. GSH levels in pReceiver-E/HepG2, pReceiver-NS3/HepG2 were significantly lower than those in pReceiver/HepG2. Conclusion DV-2 infection might lead to the GSH depletion in HepG2 cells, and GSH lost from HepG2 cells might undergo a three-step process： virus adsorption/penetration, protein synthesis and budding. E or NS3 protein stably expressed in HepG2 cells can also decrease the GSH levels.