The role of senescent cells could be crucial to the proper development of the embryo. Consequently, any action in senescent cells could have serious consequences for embryonic life.
The process by which cells cease multiplying is known as senescence. In 1961, biologists Hayflick and Moorehead cryoconserved human foetal cells, and found that these divide around 50 times and then simply stop doing so, as occurs in the human body.
In fact, senescent cells are involved in many of the signs of aging: wrinkled skin, cataracts and arthritic joints, which are produced by the effect of an increase in these cells. On the contrary, it has been found that by decreasing senescent cells in mice, signs of rejuvenation can be detected in these animals.
Considering that in all research, senescent cells have been found only in old or damaged tissues, the last place one would expect to find them would be at the very beginning of life, in the embryo. Now however, three scientific teams have reported that they have observed the same phenomenon at this point.
For the first time, senescent cells have been found in embryos, and scientists have presented proof that senescence is crucial for their proper development.
This discovery raises the possibility that the start and end of life are intimately connected. In order for life to have a good start, senescent cells are needed, i.e. youth needs a little bit of old age.
Scott Lowe, an expert in senescence at Memorial Sloan-Kettering Cancer Center, who did not participate in the research, has lauded the studies, which point to the unexpected role of old age, and predicted that it would provoke a spirited debate between developmental biologists, who study how embryos are formed.
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