Removing These Cells Could Help People to Regrow Hair


The body remains an enigma of discovery, and now research tells us that the removal of certain types of cells might help us regrow hair, run faster and live longer.

A senescent human fibroblast with a large mitochondrial network and a lot of lysosomes, both of which are typical in senescent cells. Photo Courtesy: Glyn Nelson

They are called senescent cells, and they are found in humans and animals. These cells accumulate as we age and can neither divide nor reproduce themselves. They also prevent tissue growth and have aging effects on the body.

Senescent cells do this by secreting a protein that keeps nearby cells in a daze-like state which cause organs to deteriorate. The molecules they release harm nearby tissues, and because of it organs don’t benefit from the cell rejuvenation process. Senescent cells are linked to old age diseases, including kidney failure and Type 2 diabetes.

The removal of senescent cells was first explored in the 1960s, but a renewal of interest surrounding this science occurred around the 2010s because scientists wanted to explore it as a therapeutic way to fight aging.

Benefits of Removing Senescent Cells in Mice

Two littermates, almost 2 years old; the mouse on the right had its senescent cells cleared by a drug from 1 year of age onwards. Image/Caption Credit: Jan Van Deursen

When scientists at the Mayo Clinic in Rochester removed these cells from mice in 2016, they found the rodents lived 20 to 30 percent longer. Researchers involved in the study did this by developing an injectable drug that killed senescent cells in rodents. After six months the non-senescent rodents were overall healthier than mice with a buildup of these cells. They also had better functioning kidneys, their hearts were more resilient to stress, and they developed cancers at a later age.

Human Version of Drug Still Years Away

Researchers now hope to develop drugs or anti-aging serums that will eliminate senescent cells or stop them from secreting materials that damage neighboring tissues and organs. But they caution that developing this type of drug for humans could still be years away. Safety issues and side effects would need to be further tested, which are usually understudied in rodents.  Also, the only anti-senescent drugs that currently exist also target the cell pathways of other types of cells in the body. Scientists would need to be sure that when the senescent cells are being removed, it isn’t done at the wrong time or while the patient is injured.

“When bringing in a defective car for repairs it is insufficient to remove the rust and broken parts; you also want to replace these,” says researcher of Aging Peter de Keizer of the Erasmus University Medical Center in the Netherlands.  “A perfect anti-senescence therapy would not only clear senescent cells, but also kick-start tissue rejuvenation by stimulating differentiation of nearby stem cells.”

Can This Cell Removal Reverse Aging?

While the removal of senescent cells have real, tangible health benefits — because it stalls how tissues and organs age — scientists are still unsure if they can counteract the natural aging process that has already occurred in the body.

“What if we have a brilliant anti-senescence treatment, then what? How can we hit two birds with one stone — anti-senescence and tissue rejuvenation? 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,” said de Keizer. “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.”