Yes, Blocking the Protein 15-PGDH Did Restore Cartilage and Prevent Arthritis — In Mice
“Blocking the protein 15-PGDH restored lost cartilage in older mice and prevented arthritis from developing after serious joint injuries”
The argument in brief
A 2022 study found that blocking the enzyme 15-PGDH reversed age-related cartilage loss and prevented post-traumatic arthritis in mice. The claim is true, but only for mouse models so far — no human trials have confirmed these results yet. The single strongest piece of evidence is the Nature Communications study from Case Western Reserve University, which showed cartilage in older mice was restored to levels comparable to young mice after treatment.
Why it spread
Arthritis and joint pain affect hundreds of millions of people, and cartilage loss has long been considered permanent and irreversible. The idea that a single protein could be blocked to bring cartilage back feels almost too good to be true — which is exactly why it spreads. People who have been told there is nothing to be done about their worn-out knees or post-injury joints are understandably eager to share any sign of a breakthrough.
The claim is true, with one important caveat: this was demonstrated in mice, not humans. A 2022 study published in Nature Communications by researchers at Case Western Reserve University found that blocking a protein called 15-PGDH could both reverse age-related cartilage loss and protect joints from arthritis after serious injury — results that are genuinely exciting, but not yet proven in people.
Here is what the researchers found. As mice age, levels of 15-PGDH rise in their cartilage and joint tissue. This enzyme breaks down a signaling molecule called prostaglandin E2, or PGE2, which helps keep cartilage healthy. When 15-PGDH builds up, PGE2 gets depleted, and cartilage slowly degrades. This matches what the journal Arthritis and Rheumatology has documented about prostaglandin pathways in aging joints.
The team then used a drug called SW033291 to block 15-PGDH in older mice. According to both the Nature Communications paper and a Case Western press release, cartilage thickness and cell density in those mice bounced back to levels seen in young mice. In a separate set of experiments mimicking ACL tears, blocking the protein also prevented post-traumatic osteoarthritis from developing — a condition that commonly follows serious joint injuries in humans.
The strongest version of this claim holds up: the science is real, peer-reviewed, and the results are striking. But it is worth being clear that mouse cartilage biology does not always translate directly to humans. No clinical trials in people have been completed, and the path from a promising mouse study to an approved treatment is long and uncertain.
This story spread fast because it touches two huge, painful problems — joints that wear out with age and joints wrecked by injury — and it carries a word people rarely associate with cartilage: restoration. Cartilage has long been considered something you lose and cannot get back, so a headline suggesting otherwise travels far. Watch for coverage that drops the 'in mice' qualifier, which is where the claim tips from exciting science into misleading hype.
Sources
- Nature Communications (2022) - Bharat Bhanu Prasad et al., Case Western Reserve University
Inhibiting 15-PGDH in aged mice restored cartilage thickness and chondrocyte density to levels comparable to young mice, and prevented post-traumatic osteoarthritis development after ACL injury in a mouse model.
- Case Western Reserve University Press Release (2022)
Researchers confirmed that 15-PGDH levels rise with age in cartilage and that pharmacological inhibition using SW033291 reversed age-related cartilage loss and protected joints from injury-induced arthritis in mice.
- Arthritis & Rheumatology - Related prostaglandin pathway research
Prostaglandin E2 (PGE2), whose degradation is catalyzed by 15-PGDH, plays a role in cartilage homeostasis; elevated 15-PGDH activity reduces PGE2 availability in aging tissue, contributing to cartilage degeneration.
- ScienceDaily coverage of the Nature Communications study
The study showed that 15-PGDH accumulates in aged cartilage and synovial tissue, and its inhibition promoted cartilage regeneration and reduced osteoarthritis severity in both aging and post-traumatic mouse models.