Scientists Decipher Mechanisms Underlying the Biology of Aging


Source: University of California San Diego

Summary: Researchers have deciphered the dynamics which control our cells aging process and with it implications for extending human longevity.


Understanding the factors which control aging has been an endless pursuit amongst humans, starting from the mystical fountain of youth to healthful regimens to extend life expectancy. A research team at the University of California San Diego have deciphered the dynamics which control our cells aging process and with it implications for extending human longevity. The researchers employed a combination of cutting-edge technologies in engineering, computer science and biology for analyzing the molecular processes that influence aging. The findings were published in the journal Proceedings of the National Academy of Sciences.

Cells periodically switch between “on” and “off” in their chromatin state during aging. Aged cells lose this switching capability, resulting in cell death. These findings uncover a potential cause of cellular aging and suggest new ways to promote longevity.
Credit: UC San Diego

During cell aging process, damage in their DNA is accumulated over time leads to decay in normal functioning and eventually results in death. Chromatin Silencing, a natural biochemical process which helps in protecting DNA from damage. Molecules which promote silencing process is a family of proteins – widely conserved from bacteria to human called as sirtuins. In recent years the activators of sirtuins have gained a lot of attention and are being marketed as neutraceuticals hoping to slow the process of aging. They also found chromatin silencing also stops the expression of protected DNA regions to RNAs and proteins which carry out biological functions and derailing normal physiology. As the experiments were conducted in the yeast, researchers said, the analysis of such dynamics in humans is likely to be very complex and require more studies.

Cell aging process

Credit: UC San Diego

Finally, the researchers observed, complete loss of chromatin silencing results in accelerated cell aging leading to death and continuous chromatin silencing also results in a shortened lifespan of the cells. This raises a question, does chromatin silencing or silencing the answer to delay aging process? The answer from this new study: Both.

Asst. Prof. Nan Hao said, “Instead of staying in the silencing or silencing loss state, cells switch their DNA between the open (silencing loss) and closed (silencing) states periodically during aging”, “In this way, cells can avoid a prolonged duration in either state, which is detrimental, and maintain a time-based balance important for their function and longevity.”

Hao, further added, “When cells grow old, they lose their ability to maintain this periodic switching, resulting in aged phenotypes and eventually death”, “The implication here is that if we can somehow help cells to reinforce switching, especially as they age, we can slow their aging. And this possibility is what we are currently pursuing.”

“I believe this collaboration will produce in the near future many new insights that will transform our understanding in the basic biology of aging and will lead to new strategies to promote longevity in humans,” said Hao.


More Information: Yang Li et al. Multigenerational silencing dynamics control cell aging, Proceedings of the National Academy of Sciences (2017).

DOI: 10.1073/pnas.1703379114


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