Mechanisms Of Cell Aging in Cell Culture

Abstract

A key element in the life of cells in culture is the number of cell divisions, not their life time in culture. Serially in vivo transplanted cells also exhibit a finite lifetime, which means that the cell aging is not unique only to a cell culture. There are theories suggesting that the aging of cells in culture may be associated with the aging of the organism from which they were obtained. Cells may stop dividing because of replicative aging, which is the result of telomere shortening. The aging process in cells may be induced by an intracellular process associated with shortening and uncapping of telomeres and environmental factors of a stochastic nature, among the most important of which is oxidative stress. The loss of telomeres beyond a critical value eventually induces antiproliferative signals that result in an aging. Telomeres give information about the end of replication; their function can be however recreated. Insertion of protein genes, comprised in telomerase, to aging human cells increases the length of their telomeres to lengths typical of young cells. The cells then exhibit all the characteristics of young nucleated cells. Telomerase is not only the central mechanism for regulating cells life, but it is also a mechanism that can be resumed, extending the replicative period of cells , comprising markers of gene expression characteristic of young cells, life. It is not known in what way replicative aging of cells is played by oxidative DNA damage, exposure to UV, oncogenes, which are independent of telomere shortening.