Senescent cells are unable to reproduce themselves and prevent tissue growth. A team of researchers has found that by removing senescent cells, it may bring us one step closer to the "fountain of youth". However, experts warned that an anti-ageing serum could be a few years off yet as the drugs may be unsafe for elderly people.
A drug has previously been found to help elderly mice regrow their hair, run faster and live for longer. It works by removing cells in skin tissue that naturally accumulate as the rodents grow older. The study was published in the journal Trends in Molecule Medicine
‘A perfect anti-senescence therapy would not only clear senescent cells, but also kick-start tissue rejuvenation by stimulating differentiation of nearby stem cells.’
"This strategy may bring us one step closer to the "fountain of youth," but it's important to be cautious and not hype," said researcher of aging Peter de Keizer of the Erasmus University Medical Center in the Netherlands.
They noticed that these permanently arrested cells accumulate in mature tissue and that some of them secrete factors that are harmful to tissue function and impair their neighboring cells. To explain what causes this noise in the system, de Keizer proposes a "senescence-stem lock model" in which the chronic secretion of pro-inflammatory factors by these senescent cells keeps neighboring cells in a permanent stem-like state and thereby prevents proper tissue renewal.
"A perfect anti-senescence therapy would not only clear senescent cells, but also kick-start tissue rejuvenation by stimulating differentiation of nearby stem cells. This may be complementary with, for instance, the exciting approaches recently made in the field of transient expression of stem cell factors," de Keizer stated.
There's still much basic research to be done before humans visit their local rejuvenation clinic for their annual shot of anti-aging serum. Senescent cells do have a temporary role in wound healing, so you don't want to eliminate them when you are injured or at the wrong point in time.
"I would also advise caution for claiming too much, too soon about the benefits of the fast-growing list of therapeutic compounds that are being discovered. That being said, these are clearly very exciting times, and I am confident we will find applicable anti-senescence treatments that can counteract age-related pathologies," de Keizer explained.
Researchers will also need to think about when such treatments should be administered (such as before or after the onset of certain conditions) and who would benefit the most. The potentially high cost of an anti-aging therapy, as well as off-target toxicity, could also be limiting factors for widespread market use as it is translated.
De Keizer, who plans to co-found a start-up based on the discovery of anti-senescence compounds from his lab, is hopeful that cell-penetrating peptides that can block specific activities of these retired cells could be the path forward over broad-range inhibitors.