Researchers at Stanford University have achieved a significant breakthrough in osteoarthritis treatment: by blocking a single protein called 15-PGDH, they were able to regenerate lost joint cartilage in mice. The study was published in the journal Science on June 12, 2026 (DOI: 10.1126/science.adx6649).
The protein 15-PGDH, which increases in the body with age, degrades the tissue repair messenger molecule prostaglandin E2. By inhibiting this "gerozyme," cartilage in aged mice was restored—without stem cells, solely through the reprogramming of existing cartilage cells. In an injury model, the treatment prevented the development of osteoarthritis in most animals. Initial regenerative effects were also observed in human cartilage tissue from knee surgeries after just one week.
Osteoarthritis affects millions of people worldwide; currently, there is no medication that can halt or even reverse cartilage degradation. "This is a new way to regenerate adult tissue," explains study leader Prof. Helen Blau. An oral drug targeting 15-PGDH is already in Phase 1 clinical trials for muscle weakness. The researchers hope for swift tests for cartilage regeneration—with the goal of making joint replacement surgeries obsolete in the future.
