Library · Cellular process
Cellular senescence
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Cellular senescence is the state in which a cell stops dividing. Human cells are thought to be unable to multiply endlessly: they divide only a limited number of times and then become senescent.
Part of the explanation lies at the tips of the chromosomes, in end regions called telomeres. They seem to do the job of the plastic tips on a shoelace, which keep the end from fraying. As the cell divides, the telomeres gradually shorten, and when they are lost, the end of the chromosome is exposed to the enzymes that repair DNA, and these activate a protein called p53. Together with another protein, p21, p53 can make the cell senescent.
As long as senescent cells are relatively few, cells that are not yet senescent outnumber them. When senescent cells build up in tissues, age-related diseases appear.
In brief
Cellular senescence is the state in which a cell stops dividing; human cells are thought to be able to replicate only a finite number of times before becoming senescent.
With each division, telomeres, which appear to protect chromosome ends, gradually shorten; once they are lost, the ends are exposed to DNA repair enzymes, which activate p53; together with p21, p53 can make the cell senescent.
As long as senescent cells are relatively few, other cells outnumber them; as senescent ones accumulate in tissues, age-related diseases appear.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Aging, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
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