Establishment of an animal model for human cellular againg

为了解恒河猴细胞衰老的规律，对日本恒河猴(Macaca Fuscata)、长尾恒河猴(Macaca Fascrularis)、短尾猴(Macaca Radiata)和恒河猴(Macacamulatta)共40种细胞进行了培养。从皮肤、肾脏和肺中分离贴壁细胞，在添加10%胎牛血清的RPMI1640培养液中培养，传代至终止细胞分裂。在36种细胞中，细胞经历了衰老，细胞体积变大，饱和密度降低，然后在10-20个群体倍增水平(PDL)终止了细胞分裂(死亡阶段1(M1))。而4种培养的细胞在15-25PDL时开始出现衰老形态，但通过M1继续分裂到40-100PDL，然后进入危象(死亡阶段2(M2))。日本猕猴一次培养的细胞不会终止细胞分裂(&gt；150PDLS)，并表现出转化细胞的几个特征，如锚定独立生长和失去接触抑制。所有受试者，包括转化后的受试者，都发现PDLS缩短了端粒，端粒酶活性缺失。猕猴细胞在体外呈现介于人类和啮齿动物细胞之间的中间衰老模式，而就端粒酶活性而言，它们与人类细胞相对接近。因此，我们认为猕猴是人类细胞衰老的动物模型，它们为我们研究在细胞衰老和转化的关键阶段(M1和M2)发挥作用的可能机制提供了关键。

To clarify the pattern of macaque cellular aging, a total of 40 cultures of Japanese macaque (Macaca fuscata), long-tailed macaque (Macaca fascicularis), bonnet monkey (Macaca radiata) and rhesus macaque (Macacamulatta) were carried out. Adherent cells were isolated from skin, kidney and lung, cultured in RPMI 1640 medium supplemented with 10% FBS, and subcultured until they terminated cell division. In 36 cultures, cells underwent senescence showing lager cell size and decreased saturation density, and then terminated cell division (Mortality stage 1 (M1)) at 10-20 Population Doubling Levels (PDLs). Whereas cells in four cultures first exhibited senescent morphology at 15-25 PDLs, but continued cell division through M1 up to 40-100 PDLs and then came into crisis (Mortality stage 2 (M2)). Cells in one culture of Japanese macaque do not terminate cell division (>150 PDLs) and showed several characteristics of transformed cells, such as the anchorage independent growth and loss of contact inhibition. Shortening of telomeres by PDLs and the absence of telomerase activity were identified in all of tested including the transformed one. Macaque cells showed an intermediate pattern of in vitro aging between human and rodent cells, whereas, in terms of telomerase activity, they are relatively close to human cells. It is thus suggested that the macaques serve as animal models for human cellular aging and that they provide us with a key to study possible mechanisms which play roles in the critical stages (M1 and M2) in cellular aging and transformation.