热量限制延缓人二倍体成纤维细胞衰老的体外模型

为建立人二倍体成纤维细胞IMR 90的热量限制体外模型 ,分别采用低浓度、正常浓度和高浓度葡萄糖培养条件 ,常规传代培养IMR 90细胞 ,利用综合细胞衰老指标对模型进行评价 .低、正常和高浓度葡萄糖培养条件组IMR 90细胞平均寿限分别为 5 8 3、5 5 0和 4 7 2PDL(群体倍增水平 ) .低浓度葡萄糖培养IMR 90细胞早期增长速度有所减慢 ,但仍保持对生长因子诱导的细胞增殖能力 ,并使晚期IMR 90处于细胞周期S期的比例以及其DNA修复能力显著高于其他条件培养的晚期细胞 .低浓度葡萄糖培养IMR 90晚期细胞的半乳糖苷酶染色阳性率亦明显低于其他条件培养的晚期细胞 .实验结果表明 ,低浓度葡萄糖培养可以延缓IMR 90复制衰老 ,建立了热量限制延缓衰老体外模型 ,为进一步探讨热量限制延缓衰老作用机制的研究打下基础

Construction of the Model of Caloric Restriction Retarding Replicative Senescence with Human Diploid Fibroblast IMR-90

In order to construct the model of caloric restriction(CR) with human diploid fibroblast IMR 90,IMR 90 was cultured in normal concentration glucose (5 0 mmol/L,NG),lower concentration glucose(3 0 mmol/L,LG)and high concentration glucose(22 5 mmol/L,HG) media, respectively.Biomarkers of replicative senescence were assess in this model.The averages of life span of IMR 90 under NG,LG and HG culture conditions were 55 0,58 3 and 47 2 population doubling levels(PDL),respectively.Although the cell growth rate of IMR 90 at early stage in LG culture became significantly slower than that in NG and HG culture,its proliferative capacity to the stimulation of growth factor(EGF) was almost the same as cells cultured in NG and HG media.At late stage,the percentage of S phase of cell cycle and the levels of unscheduled DNA syntheses in LG group were significantly higher than those in NG and HG groups. The positive rate of senescence associated β galactosidase(SA β gal) staining at late stage of LG group was significantly lower than that cells of late stage in NG and HG cultrue.These results suggested that the model of caloric restriction in vitro was constructed by using IMR 90 cultured in lower glucose concentration medium and caloric restriction could retard the replicative senescence of IMR 90.