To investigate the adaptation of poliovirus Sabin 2 in human embryonic lung diploid fibroblast（KMB17） and its relation to nucleotide mutations of 5′ noncoding region（5′NCR）,the Sabin 2 vaccine virus was passaged...To investigate the adaptation of poliovirus Sabin 2 in human embryonic lung diploid fibroblast（KMB17） and its relation to nucleotide mutations of 5′ noncoding region（5′NCR）,the Sabin 2 vaccine virus was passaged serially in KMB17 for seventeen passages.The infectious titers of Sabin 2 virus increased along with the passages,the highest titer reached 8.0 LgCCID50/ml at passage 13（P13）.During passage,there were three nucleotide mutations appeared in 5′NCR,G changed to C at position 20,C to U at position 189 and G to A at position 481.The results showed that Sabin 2 poliovirus adapted well in KMB17 after 17 passages.The nucleotide mutation at position 481 that appeared from passage 3 on indicated the possibility of virulent reversion.展开更多
文摘To investigate the adaptation of poliovirus Sabin 2 in human embryonic lung diploid fibroblast（KMB17） and its relation to nucleotide mutations of 5′ noncoding region（5′NCR）,the Sabin 2 vaccine virus was passaged serially in KMB17 for seventeen passages.The infectious titers of Sabin 2 virus increased along with the passages,the highest titer reached 8.0 LgCCID50/ml at passage 13（P13）.During passage,there were three nucleotide mutations appeared in 5′NCR,G changed to C at position 20,C to U at position 189 and G to A at position 481.The results showed that Sabin 2 poliovirus adapted well in KMB17 after 17 passages.The nucleotide mutation at position 481 that appeared from passage 3 on indicated the possibility of virulent reversion.
文摘目的:探讨敲减高迁移率族蛋白A2( HMGA2 )基因表达对转化生长因子β1(TGF-β1)诱导的人胚肺成纤维细胞活力、凋亡、胶原合成和氧化应激的影响。方法:实验分为空白组、TGF-β1组、阴性转染对照组和HMGA2 siRNA(si-HMGA2)组。Western blot 检测HMGA2、AKT和p-AKT蛋白水平;MTT法及流式细胞术分别检测细胞活力及凋亡率;RT-qPCR检测Ⅰ型胶原蛋白(COL -Ⅰ)和COL-Ⅲ的mRNA表达;DCFH-DA探针检测细胞活性氧簇(ROS)的含量。结果:与空白组比较,TGF-β1组HMGA2和p-AKT的蛋白水平、细胞活力及COL -Ⅰ和COL-Ⅲ的mRNA表达均明显升高,细胞凋亡率及ROS水平则明显降低( P <0.05);与TGF-β1组比较,si-HMGA2组HMGA2和p-AKT的蛋白水平、细胞活力及COL -Ⅰ和COL-Ⅲ的mRNA表达均明显降低,细胞凋亡率及ROS水平则明显升高( P <0.05)。结论:敲减HMGA2 基因可抑制TGF-β1诱导的人胚肺成纤维细胞生长和胶原合成,促进细胞凋亡及ROS产生,其机制可能与下调PI3K/AKT信号通路有关。
