PTTG1在D-GalN/TNF-α所致LO2肝细胞损伤中的变化及对细胞凋亡的影响

PTTG1 expression variation in D-GalN/TNF-α-induced LO2 cell injury and effect on cell apoptosis

目的探讨垂体肿瘤转化基因1(PTTG1)在D-半乳糖胺(D-GalN)/TNF-α所致LO2肝细胞损伤中的变化,以及对细胞凋亡的影响和机制.方法通过蛋白免疫印迹法和免疫组织化学检测D-GalN/TNF-α作用前后LO2肝细胞中PTTG1的表达情况,使用PTTG1 shRNA慢病毒建立PTTG1干扰的LO2肝细胞稳转株,并通过蛋白免疫印迹法和RT-PCR检测细胞凋亡相关蛋白cleaved Caspase-3和内质网应激通路相关基因糖调节蛋白(GRP 78)、CCAAT/增强子结合蛋白同源蛋白(CHOP)的表达.结果D-GalN/TNF-α作用于LO2肝细胞0.5 h后PTTG1蛋白表达开始逐渐增加,1 h至24 h后PTTG1蛋白表达均高于未处理组(P均<0.05);与未处理组相比,D-GalN/TNF-α作用6 h后的LO2肝细胞免疫组织化学PTTG1阳性细胞数增加(P均<0.05).与阴性对照组相比,PTTG1稳定干扰的LO2肝细胞中的cleaved Caspase-3及GRP 78、CHOP表达增加(P<0.05).结论PTTG1在D-GalN/TNF-α所致的LO2肝细胞损伤中表达增加,且干扰PTTG1的表达可促进LO2肝细胞凋亡并激活GRP 78/CHOP内质网应激通路.

Objective To investigate the variation of pituitary tumor transforming gene 1(PTTG1)expression in D-GalN/TNF-α-induced LO2 cell injury,evaluate the effect on cell apoptosis and unravel its underlying mechanism.Methods The expression levels of PTTG1 in the LO2 cells before and after D-GalN/TNF-αtreatment were detected by western blot and immunohistochemical staining.PTTG1-interfered LO2 cells were established by stably transfected with shRNA lentivirus targeting PTTG1 gene.The expression levels of apoptosis-related protein cleaved Caspase-3 and endoplasmic-reticulum-stress-related genes GRP 78 and CCAAT/enhancer-binding protein homologous protein(CHOP)were determined by Western blot and RT-PCR.Results The expression of PTTG1 protein in the LO2 cells was gradually up-regulated at 0.5 h after treated with D-GalN/TNF-α,which was significantly higher than that in the untreated group at 1-24 h after treatment(all P<0.05).Compared with the value in the untreated group,the quantity of D-GalN/TNF-α-treated LO2 cells with positive PTTG1 was significantly increased(P<0.05).The expression levels of cleaved Caspase-3,GRP 78 and CHOP in the PTTG1-interfered LO2 cells were significantly higher compared with those in the negative controls(all P<0.05).Conclusions PTTG1 expression is up-regulated in D-GalN/TNF-α-induced LO2 cell injury.Interfering PTTG1 expression can promote the LO2 cell apoptosis and activate the GRP 78/CHOP endoplasmic reticulum stress signaling pathway.