The Grapevine

Scientists Uncover What Keeps Cells Young

The obsession with youth is perpetuated by the media and the idea of being ageless is chased by individuals across generations, especially those on the edge of middle age and people entering their fifties. Scientists have been focused on delaying aging rather than improving the aging process as we approach it naturally. 

Researchers at the University of Southern California Viterbi School of Engineering have decided to take this unique approach and focus on the key processes that causes aging in human beings. "To drink from the fountain of youth, you have to figure out where the fountain of youth is, and understand what the fountain of youth is doing," Nick Graham,  Assistant Professor of Chemical Engineering and Material Sciences, said. 

A graduate student working under him at the Graham lab, lead author Alireza Delfarah, decided to study the process during which cells stop proliferating called senescence. When senescence occurs, it could manifest in a host of diseases such as arthritis, osteoporosis and cardiovascular trouble. 

“Senescent cells are effectively the opposite of stem cells, which have an unlimited potential for self-renewal or division. Senescent cells can never divide again. It’s an irreversible state of cell cycle arrest,” said Delfarah in the press release issued by the University. 

The team made a path breaking discovery that senescent cells did not produce a group of chemicals called nucleotides, which are essential for forming DNA. They forcefully stopped the production of nucleotides to verify this in young cells and found it to be true. 

wrinkles Scientists at the University of California have discovered the process that could help find the elixir of youth Photo Courtesy of Pixabay

“This means that the production of nucleotides is essential to keep cells young. It also means that if we could prevent cells from losing nucleotide synthesis, the cells might age more slowly.” said Delfarah. The study was recently published in The Journal of Biological Chemistry and closely studied the phenomenon of senescence from various angles.

When Scott Fraser, Provost Professor of Biological Sciences and Biomedical Engineering, took 3D images of the cells, he surprisingly found that senescent cells had two nuclei and both do not multiple and synthesize DNA.

The other difference between this particular study and others that focused on senescent cells is that the process was studied in cells called fibroblasts, whereas this study examined the occurrence of senescence in epithelial cells. However, there were some precaution scientists have to take for the sake of preventing cancer

Why? If senescence is interfered with, it could risk the development of cancer. When body's cells are damaged due to cancerous properties, they enter into a state of senescence as a defense mechanism to prevent cancer from spreading. Graham said, “the goal was not to completely prevent senescence, because that might unleash cancer cells. But then on the other hand, we would like to find a way to remove senescent cells to promote healthy aging and better function.”

Graham and his team are currently experimenting with drugs to help human beings age better in an emerging field of research called senolytics. So far, studies conducted on mice have shown that by eliminating senescent cells, the mice becomes rejuvenated and can live a more functional life.

While clinical trials on human beings are still in nascent stages, it was important to understand the uniqueness of a senescent cell, so that drugs do not negatively affect non-senescent cells and do not cause any side effects.