Telomeres And Ageing – Study Reveals How We Age
Aging is a natural process, which researchers are increasingly struggling to understand at molecular level, hoping that one day, they will mange to reverse it. It may sound daring but small steps forward are made every day by scientists throughout the world. It is the case of a new study available in the Nature Communications journal, that links damage to telomeres (chains of DNA that are present at the ends of the chromosomes of all body cells) to the ageing process.
All our body cells divide in order to replace dead, malfunctioning or aged cells. When cells divide, they forward a copy of their DNA to the daughter cells. Since the DNA molecule is very large, it needs to be condensed to fit inside the cell nucleus, giving birth to chromosomes. Each chromosome presents at its end a telomere which shortens with each cell division. Previous studies have shown that when telomeres are too short, they reach a critical minimum length that makes cells unable to divide.
The study, conducted at The Newcastle University now suggests that critical minimum telomere length is not the only factor that determines cells to halt their division process. According to study leader, Dr. João Passos telomere shortening is indeed one factor that increases the risk of certain diseases and cellular death but the stress induced DNA damage of telomers could also play a key role in the ageing process. It was also found that even long telomers but with damaged DNA makes body cells unable to divide.
With age, all cells suffer different mutations of the DNA (molecule that stores the encoded genetic information needed for protein synthesis and replication). These mutations that are largely caused by the action of free radicals can be fixed by different cell DNA repair mechanisms. The sudy reveales that sensitive to stress telomeres are not so efficiently repaired. During the division process they are transmitted to the next generation of cells which gradually reduce their ability to regenerate – ageing.
These findings represent a huge step forward in understanding how exactly telomers influence the ageing process. It seems that is not just the telomore length that matters when when it comes to ageing, but also how they respond to damage. Future studies aim to elucidate what exactly makes these chromosome ends so special, hoping to find drugs that can interfere with telomere damage and renew it.