Chromatin and aging
Since ancient times, mankind has been asking questions about aging and endless life, starting from the mystical "sources of youth" and ending with practical recommendations for a healthy lifestyle.
A group of scientists led by biologist Nan Hao from the University of California at San Diego in a study on yeast deciphered one of the processes that control cell aging. Perhaps this knowledge will help to develop ways to prolong human life.
The researchers combined engineering, computer and biological approaches to analyze the molecular processes occurring in an aging cell.
During the life of a cell, damage accumulates in its DNA, with age it ceases to perform its functions normally and eventually dies. A natural process known as chromatin silencing allows DNA to be protected from damage: certain areas cease to be available for transcription (reading). Chromatin silence occurs with the participation of a group of sirtuin proteins. Recently, they have received a lot of attention, marketers position them as substances that can slow down aging.
However, it was found that when chromatin is silent, the DNA sections carrying information about proteins necessary for the normal functioning of the cell become inaccessible, which leads to disruption of the cell and its death. But the complete removal of the silence mode also leads to cell death due to the acceleration of aging processes.
So which process exactly will slow down aging and prolong life, silence or chromatin activity? It turns out both.
According to researchers, nature has come up with a wise solution to this dilemma: it consists in alternating modes of activity and silence of genes. Thus, the cells are not in any of the modes long enough for irreversible changes to occur.
Cells consistently switch from chromatin activity mode to silence mode. With age, the ability to quickly change the "on" and "off" modes is lost, which naturally leads to their death. This diagram demonstrates the mechanism of cell aging. Source: UC San Diego.
Recall that the study was conducted on yeast cells. The authors suggest that such work with human cells will be much more difficult and will require the development of new methods of data collection, analysis and interpretation. Nevertheless, this is a very promising direction, it can shed light on the peculiarities of human aging and ways to prolong life.
Article by Yang Li et al. Multigenerational silencing dynamics control cell aging is published in PNAS.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru