The effects of PEG10 on hydrogen peroxide （H2O2）-induced apoptosis in human normal liver cell line L02 were investigated. The PEG10 gene was transfected into L02 cells by lipofectamine, the positive clone was screened by G418 and defined as L02/PEG10, while the cell transfected with empty expression vector （pEGFP-N1） was defined as L02/vector. L02/vector and parental L02 cells served as control. RT-PCR and Western blotting were employed to detect the expression of target genes. H2O2 （50–400 mmol/L） was administered to induce the apoptosis of L02 cells. Cells viability was measured by MTT and the morphological changes of apoptotic cells were determined by fluorescence microscopy using hoechst33342 nuclei staining. DNA fragmentation was observed by agarose gel electrophoresis. PEG10 mRNA and protein levels in L02/PEG10 cells were significantly increased as compared with those in the control cells. After treatment with 400 mmol/L H2O2 for 24 h, the cellular growth inhibition rate of L02/PEG10 cells was significantly lower （58.2%） than that of L02 （92.5%） and L02/vector （88%）. Distinct morphological changes characteristic of cell apoptosis such as karyopyknosis and conglomeration were not observed in L02/PEG10. Ladder-like DNA fragmentation in a dose-dependent manner was observed in both L02 and L02/vector cell lines, but not in L02/PEG10. PEG10 over-expression significantly inhibited cytotoxicity induced by H2O2 on human normal liver cell line L02 by antagonizing H2O2-induced apoptosis.
目的:对比小鼠白蛋白(mouse albumin promoter,ALB)启动子调控下的增强型绿色荧光蛋白(en-hanced green fluorescent protein,EGFP)在不同细胞系中的转录活性。方法:以小鼠全血基因组DNA为模板,聚合酶链反应(polymerase chain reaction,PCR)扩增ALB启动子序列,克隆至pEGFP-1中,构建重组体pALB-EGFP;在Lipofectamine介导下将pALB-EGFP、pEGFP-N1转染人胎肝细胞L02、人宫颈癌细胞HeLa、人结肠癌细胞SW480、人胰腺癌细胞Bxpc-3;荧光显微镜和流式细胞仪对各转染细胞中EGFP的表达进行检测。结果:pALB-EGFP构建成功;L02转染pALB-EGFP72h后,ALB启动子可起始EGFP的表达,转录活性为人巨细胞病毒(cytomegalovir-us,CMV)启动子的1/4,其它转染细胞的ALB不能起始EGFP的转录;稳定筛选后,ALB的转录活性达到与CMV相当的水平。结论:构建的重组载体在肝脏来源细胞中具有较高的转录活性,为建立肝脏特异性表达目的基因的转基因小鼠模型奠定了基础。
