Senescence is associated with aging.
Senescence is the characteristic of that or that senescent . This adjective , which comes from the Latin word senescens , refers to someone who begins to age .
For example: "It pains me to notice Uncle Juan's senescence" , "Scientists investigate the senescence of cells to try to find a cure for this illness" , "The authorities do nothing to reverse the senescence of the people" .
What is senescence
In its broadest sense, senescence is an irreversible change that occurs in a system or structure over time. The analysis of these modifications generally allows us to estimate the time that elapsed between two specific moments.
Senescence is associated with deterioration : the passage of years causes the organism or structure to fail to retain its capabilities intact. In this way, it loses functionality, efficiency, strength , among other possible factors, while simultaneously increasing its vulnerability .
Senescence is irreversible, although its effects can be delayed.
Aging in humans
It is easy to understand the notion of senescence if we think about the life of a human being . From birth to a certain age, people experience a development process. However, then a reverse process begins, which can be defined as senescence or aging .
The aging individual finds it difficult, for physical reasons, to perform tasks that were previously easy for him or her. You get more tired, have less strength, move more slowly, and are more vulnerable to disease.
Although senescence cannot be stopped or reversed, it is possible to carry out certain actions that help minimize or delay its effects .
cellular senescence
The process that begins as a direct consequence of the damage and stress that takes place in a cell is known as cellular senescence , and it is an alternative response path to what is called apoptotic cell death (the destruction that the organism programs to control its own growth and development). This process is essential for the suppression of cancer cells and is also linked to the task of repairing tissues and their inflammation, all of which is related to the development of tumors.
On the other hand, cellular senescence also participates in processes such as the promotion of cancerous tumors and aging, both with a negative impact on the organism and certainly at the other extreme of those mentioned in the previous paragraph. This can be taken as a case of antagonistic pleiotropy , a phenomenon that is evident when a gene produces different and apparently unrelated effects.
The first to describe these processes was the anatomy expert Leonard Hayflick , born in the United States in 1928 , in the context of research on the in vitro growth of human fibroblasts (a type of cell that is born and dies in the connective tissue, with a lattice structure and an essential role in healing wounds). He then discovered that cells can only go through a maximum of 60 replication cycles, which is why their growth is limited, contrary to what the French scientist Alexis Carrel had postulated, according to whom in vitro cultures gave rise to infinite development.
Cellular senescence is a process that can be triggered by various stimuli, and each of them, combined or individually, can give the same results. One such stimulus, for example, is the shortening of telomeres (the ends of a chromosome), which occurs when the enzyme telomerase is missing in most somatic cells. When working in vitro, on the other hand, it is possible to detect various causes of stress that lead to senescence, such as oxidative stress, serum and inadequate substrates.