乙肝病毒X蛋白抑制小鼠足细胞系MPC5增殖并促进其凋亡

目的探讨乙肝病毒X蛋白(HBx)对条件永生型小鼠足细胞系(MPC5)增殖与凋亡的影响。方法用携带HBx基因的pEX质粒转染MPC5细胞,实时荧光定量PCR(RT-qPCR)验证转染效率。实验分空白对照组(MPC5 group)、阴性对照组(MPC5-pEX-neo group)、HBx转染组(MPC5-pEX-HBx group)。MTT法检测足细胞存活率;流式细胞计量术检测细胞凋亡;Western blot检测细胞中nephrin、STAT3、JAK2、p-STAT3和p-JAK2、caspase-3蛋白表达。结果 HBx转染MPC5细胞48 h后HBx表达最高。HBx转染组中nephrin蛋白表达水平显著低于空白对照及阴性对照(均P<0.01)。转染HBx基因后足细胞增殖明显受抑,同时凋亡率显著增高(均P<0.01)。此外,HBx转染组STAT3、p-STAT3、JAK2和p-JAK2蛋白表达较空白对照及阴性对照组均显著增高(均P<0.01), caspase-3在HBx转染组中的表达也显著增高(均P<0.01)。结论 HBx可下调足细胞中nephrin蛋白表达,抑制足细胞增殖,并促进其凋亡的发生。其作用机制可能与STAT3/JAK2信号通路活化有关。

Hepatitis B virus X protein inhibits the proliferation and promotes the apoptosis of mouse foot cell line MPC5

Objective To investigate the effect of hepatitis b virus X (HBx) on the proliferation and apoptosis of immortalized mouse foot cell line MPC5. Methods The pEX plasmid with HBx gene was transfected into MPC5 cells,and then used quantitative real-time PCR(RT-qPCR) to test the transfection efficiency. The experiment animals were divided into three groups: HBx transfection group (MPC5-pEX-HBx group):liposome+HBx-plasmid;negative control group (MPC5-pEX-neo group): liposome+empty plasmid;blank control group (MPC5 group). Survival rate of each group was determined by MTT method. The cell apotosis was analyzed by flow cytometry. Western blot was employed to detect the nephrin, STAT3,p-STAT3,JAK2,p-JAK2,caspase-3 proteins level. Results There was the highest expression of HBx in 48 h after transfection with MPC5 cells. The expression level of nephrin protein in HBx transfection group was lower than that in blank and negative control ( P <0.01). After transfection of HBx gene, the podocyte proliferation was inhibited, and the apoptosis rate was significantly increased( P <0.01), STAT3, p-STAT3 ,JAK2 and p-JAK2 expression were all increased( P <0.01),and caspase-3 expression was up-regulated. Conclusions HBx reduces the nephrin expression in podocytes, inhibits the podocytes proliferation and promotes apoptosis. The mechanism may be related to the activation of STAT3/JAK2 signaling pathway.