The signs of aging can be a literal pain, especially for those with sedentary lifestyles who are more prone to experiencing joint and muscle pains. While professionals recommend having an active lifestyle to lower the risk of osteoarthritis development, researchers look inside our own bodies to determine how to fight the natural course of aging.

A previous study found that removing senescent (or old) cells from our bodies could be the key to feeling more rejuvenated. Now, a group of researchers discovered that applying the same principle to the joints of osteoarthritic patients could reverse its effects.

Senescent Cells

Senescent cells are the old cells that accumulate in our bodies and contribute to age-related physical conditions as we grow older — from poor stamina to weak internal organs. Several studies showed that clearing out these old cells would improve age-related conditions and, by extension, prolong human life.

Removing Old Cells In Mice

A study published in Nature Medicine journal on April 24 found that removing senescent cells in the knee joints of mice promoted cartilage growth and repaired joints.

The experiment was done on a group of young and old mice separately in order to determine the procedure's effectiveness.

The team of researchers first took the young mice and cut their anterior cruciate ligaments (ACL) in a surgical procedure in order to mimic injury. After 14 days, when the mice's joints began to show signs of degradation, the researchers injected them with UBX0101 — an experimental drug that has been proven effective in removing senescent cells. The same thing was done to the old mice.

In both cases, senescent cells were reduced by 50 percent, which was enough to allow the joints to begin the healing process. There were, however, some slight differences in the results.

In the young mice, the genes associated with cartilage repair were activated soon after the injections and allowed the young mice to properly heal.

The old mice, which started out with thinner cartilage and showed signs of more pain, did not experience cartilage regeneration. Only pain was reduced for the older counterparts.

Testing UBX0101 On Humans

In order to determine if the same effect would happen to humans, the researchers cultured cartilage cells from severely osteoarthritic patients. It took four days before the senescent cells began to reduce dramatically and, like the younger mice, started to regenerate and form new cartilage.

"What was most striking about the results in human tissue is the fact that removal of senescent cells had a profound effect on tissue from very advanced osteoarthritis patients, suggesting that even patients with advanced disease could benefit," said Dr. Jennifer Elisseeff, Morton Goldberg Professor of Ophthalmology and director of the translational tissue engineering center at the Johns Hopkins Wilmer Eye Institute.