Influence of Donor Age and Species Longevity on Replicative Cellular Senescence

The replicative life span of cell strains obtained from multiple explants from the same individual is highly variable, additional variability is added when strains are obtained from different individuals. This variability is probably due to both technical issues and heterogeneity inside the tissues. Notwithstanding these limitations, many scientists searched for an inverse relationship of proliferative potential and donor age. Reviewing this literature, we conclude that this inverse correlation is likely more dependent to developmental stages than to aging per se; i.e. cells taken from a developing organism have higher replicative capacity than cells taken from an adult. Replicative senescence has been studied also across species searching for a positive relationship with longevity. Recently it has been show that when specific culture conditions (mainly low oxygen tension) are applied, strains from several species appear immortals. Moreover, for species that do present cellular senescence, it seems that replicative capacity relates primarily to species adult body mass more than to longevity.