Embryos reverse aging to become younger than when they were created
All the cells in the body are subject to aging, right? So how can the joining of eggs and sperm adult people (already quite aged) generate a completely young organism, with cells without the effect of age? It was with these questions in mind that biologists at Harvard Medical University discovered a mechanism of rejuvenation in human embryos.
Using machine learning and knowledge of epigenetics, the researchers were able to identify an event of rejuvenation of the embryo during its formation. Remembering, epigenetics refers to all molecules that interact with genetic material, changing their function.
Through certain epigenetic marks it is possible to quantify how old a cell is. Thus, the researchers observed that the zygote and blastocyst phases (the first stages of development) had more aging marks than the embryo afterwards, suggesting the aforementioned rejuvenation of the cell in the meantime during development.
Even in cells in laboratory cultures, which tend to accumulate more epigenetic marks due to the low amount of oxygen and other factors, the rejuvenated cells showed practically no indication of cell aging.
Rejuvenation even before birth
This reduction in epigenetic marks of aging helps to understand how a puppy is not born with its aging cells. Remembering, epigenetic marks are not inside the DNA, but rather bind to it, promoting or blocking some functions. These brands, therefore, are not transferred parents to children, but activated by cell signaling.
The results are still quite preliminary, and little is known about what really causes this rejuvenation event after the blastocyst stage. However, a reversal of cellular aging can eventually help in the development of age-related illnesses and even an individual's epigenetics.
Cancer and Alzheimer's, for example, have genetic roots, but they are also deeply related to an individual's age and also to their environment. Understanding how this mechanism works, therefore, can be essential to treat diseases related to aging in its deepest origin, since cell aging originates at some point after the implantation of the zygote and before embryogenesis.
However, as stated before, the results are quite preliminary, and it will take a few more years, perhaps decades, to completely unravel this mechanism of rejuvenation.