Egorov E E, Semenova I V, Andreeva V V, Akimov S S, Prudovskiĭ I A, Zelenin A V
Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991 Russia.
Mol Biol (Mosk). 2002 May-Jun;36(3):466-71.
The Japanese senescence accelerated mice (SAM) are a group of the low-longevity mouse lines and represent a new convenient model for studying the senescence process. We studied the proliferation of embryo fibroblasts of SAMP1 and SAMR1 mouse lines. It was shown that fibroblasts of the shortest longevity line SAMP1 have a markedly decreased proliferative potential of the mean 8.7 population doublings, whereas fibroblasts of a relatively high-longevity line SAMR1 have an average proliferative potential of 12.3 doublings. The fibroblast senescence in both lines is accompanied by a simultaneous lowering of the cell proliferative response to the blood serum, epidermal, fibroblast, and platelet-derived growth factors. At initial stages of the cell culture growth, lines SAMP1 and SAMR1 exhibit the same reactions to growth factors, but already beginning from the fifth doubling, the SAMP1 cell response is sharply decreased as compared with SAMR1. Lowering the proliferative reaction is accompanied by a decreased phosphorylation of tyrosine in the cell proteins responsible for mitogenic reaction. Thus, the parallel decrease of proliferative response to different growth factors during fibroblast senescence is most likely due the emergence of a regulatory block at common stages of the mitogenic signal transduction.
日本衰老加速小鼠（SAM）是一组低寿命小鼠品系，是研究衰老过程的一种新型便捷模型。我们研究了SAMP1和SAMR1小鼠品系胚胎成纤维细胞的增殖情况。结果显示，最短寿命品系SAMP1的成纤维细胞增殖潜能显著降低，平均群体倍增次数为8.7次，而相对高寿命品系SAMR1的成纤维细胞平均增殖潜能为12.3次倍增。两个品系的成纤维细胞衰老均伴随着细胞对血清、表皮生长因子、成纤维细胞生长因子和血小板衍生生长因子的增殖反应同时降低。在细胞培养生长的初始阶段，SAMP1和SAMR1品系对生长因子表现出相同的反应，但从第五次倍增开始，与SAMR1相比，SAMP1细胞的反应急剧下降。增殖反应降低伴随着负责有丝分裂反应的细胞蛋白中酪氨酸磷酸化的减少。因此，成纤维细胞衰老过程中对不同生长因子增殖反应的平行降低很可能是由于在有丝分裂信号转导的共同阶段出现了调节阻滞。
