Stanford: Cartilage Restored, Improving Joints

Stanford University researchers have uncovered a promising new approach that may help the body regrow cartilage in aging joints — and could even reduce the risk of osteoarthritis after certain knee injuries.

Osteoarthritis is the most common form of arthritis and affects an estimated 595 million people worldwide. The condition develops when joint cartilage gradually breaks down over time, often due to aging, excess weight, or injury.

Cartilage acts as a cushion between bones. In osteoarthritis, inflammation can speed up the breakdown of collagen, a key structural protein in cartilage. As collagen is lost, cartilage becomes thinner and weaker, which can lead to swelling, stiffness, and pain.

Study Details

In a recent study, the Stanford team focused on an enzyme called 15-PGDH, which increases with age. The researchers refer to it as a “gerozyme” because of its link to aging-related tissue decline.

When scientists blocked 15-PGDH in older mice and in mice with joint injuries, they found less inflammation, improved cartilage repair and healthier overall joint tissue.

According to ScienceDaily, the therapy improved cartilage not only in mice, but also in human cartilage samples tested in the lab.

Help With ACL Tears

TearsThe findings may also be meaningful for people who suffer ACL tears, a common sports injury. Even with surgical repair, many patients later develop osteoarthritis in the injured joint.

In the study, injured mice that received injections of the 15-PGDH–blocking compound were much less likely to develop osteoarthritis. Untreated injured mice had higher levels of 15-PGDH and developed arthritis-like joint damage within weeks.

Human Experiments Promising

The Stanford team also tested the inhibitor on cartilage taken from patients undergoing knee replacement surgery. After one week, the treated cartilage showed signs of reduced 15-PGDH activity and less degeneration.

“This is a new way of regenerating adult tissue, and it has significant clinical promise for treating arthritis due to aging or injury,” said study author Helen Blau, PhD, a professor of microbiology and immunology at Stanford. “We were looking for stem cells, but they are clearly not involved. It’s very exciting.”

Blau added that early-stage testing of a 15-PGDH inhibitor for muscle weakness suggests the drug may be safe in healthy volunteers.

“Our hope is that a similar trial will be launched soon to test its effect in cartilage regeneration,” Blau said. “Imagine regrowing existing cartilage and avoiding joint replacement.”

The study was published in the journal Science.