New cause of cell aging discovered

Posted on July 30, 2019

Alireza Delfarah, a graduate student in the Graham lab focused on senescence, a natural process in which cells permanently stop creating new cells. This process is one of the key causes of age-related decline, manifesting in diseases such as arthritis, osteoporosis and heart disease.

Senescent cells are the opposite of stem cells, which have an unlimited potential for self-renewal or division. Senescent cells can never divide again, it is an irreversible state of cell cycle arrest. Researchers discovered that the aging, senescent cells stopped producing a class of chemicals called nucleotides, which are the building blocks of DNA. When researchers experimented and took young cells and forced them to stop producing nucleotides, they became senescent, or aged.

These findings show that the production of nucleotides is essential to keep cells young and if scientists can find a way to prevent cells from losing nucleotide synthesis, the cells might age more slowly. Graham's team examined young cells that were proliferating robustly and fed them molecules labeled with stable isotopes of carbon, in order to trace how the nutrients consumed by a cell were processed into different biochemical pathways.

Graham said that senescence is most widely known as the body's protective barrier against cancer: When cells sustain damage that could be at risk of developing into cancer, they enter senescence and stop proliferating so that the cancer does not develop and spread.

Graham’s goal is not to completely prevent senescence, because that might unleash cancer cells. Instead, the ideal is to remove senescent cells to promote healthy aging and better function. Experiments with mice have shown that by eliminating senescent cells, mice age better, with a more productive life span.

The findings of senescent cells are important as it contributes to successful senolytic drugs to be designed in order to avoid affecting the normal, non-senescent cells. Studying the senescent cell metabolism and trying to figure out how the senescent cells are unique is necessary to design targeted therapeutics around these metabolism pathways.

Category(s):Aging & Geriatric Issues

Source material from Science Daily