[Systemic aging and replicative senescence: in vivo and in vitro]

Cultured cells lose the ability of DNA synthesis, mitosis, and finally the ability of cell proliferation after they have undergone a finite number of population doublings in vitro, though the cells still maintain the basic metabolic process. This is termed replicative senescence. We review the prevalence of replicative senescence, summarize the features of senescent cells, and then focus on the links between systemic aging and replicative senescence. The present knowledge, albeit still incomplete, proposes that replicative senescence is a reflection of systemic aging at cell level, and it fully confirms replicative senescence as a good model for the research of systemic aging.