15-Hydroxyprostaglandin Dehydrogenase Function and Age-Related Changes
15-PGDH is a prostaglandin-degrading enzyme that increases with age in multiple tissues including skeletal muscle, and this age-associated increase is detrimental—inhibiting 15-PGDH in older individuals is advantageous for restoring muscle mass, strength, cartilage regeneration, and neuromuscular function.
What 15-PGDH Does
15-hydroxyprostaglandin dehydrogenase (15-PGDH, encoded by the HPGD gene) is the primary enzyme responsible for degrading prostaglandins, particularly PGE2, PGD2, and PGF2α 1. It catalyzes the rapid oxidation of biologically active 15-hydroxy-prostaglandins into 15-keto-prostaglandins with substantially lower biological activity 1.
The enzyme functions as a metabolic antagonist or "brake" for cyclooxygenase-2 (PTGS2/COX-2), effectively controlling prostaglandin signaling 2. In the context of colorectal cancer prevention, aspirin's chemopreventive effects are enhanced by HPGD expression through catabolism of PGE2 2.
Age-Related Changes in 15-PGDH Expression
15-PGDH expression markedly increases in aged tissues and has been identified as a "gerozyme"—a hallmark aging-associated enzyme 3, 4. This increase occurs in:
- Skeletal muscle: Aged muscle shows elevated 15-PGDH in both myofibers and interstitial cells (including macrophages) 3
- Articular cartilage: Expression increases in aged or injured joints 5
- Denervated muscle: Injury triggers early expression of this aging-associated enzyme 4
The age-associated increase in 15-PGDH leads to a consequent reduction in PGE2 signaling, which contributes to multiple age-related pathologies 3.
Is More 15-PGDH Advantageous for Older People?
No—higher 15-PGDH activity is definitively disadvantageous in older adults, and inhibiting this enzyme provides substantial benefits.
Evidence from the Highest Quality Recent Studies:
In aged skeletal muscle 3 (2021, Science):
- Increased 15-PGDH contributes directly to muscle atrophy in aged mice
- Overexpression of 15-PGDH in young muscles induced atrophy
- Inhibition of 15-PGDH (genetic depletion or small-molecule inhibitor) increased aged muscle mass, strength, and exercise performance
- Benefits arise from physiologically increased PGE2 concentrations, which:
- Augmented mitochondrial function
- Enhanced autophagy
- Decreased TGF-β signaling
- Reduced ubiquitin-proteasome pathway activity
In aged cartilage and osteoarthritis 5 (2026, Science):
- Both systemic and local 15-PGDH inhibition led to articular cartilage regeneration
- Reduced OA-associated pain
- Decreased hypertrophic-like chondrocytes expressing 15-PGDH
- Increased extracellular matrix-synthesizing articular chondrocytes
In neuromuscular denervation 4 (2023, Science Translational Medicine):
- 15-PGDH inhibitor treatment promoted motor axon regeneration
- Accelerated recovery of force after acute nerve crush injury
- In aged mice with chronic denervation: increased motor neuron viability, restored neuromuscular junctions, and markedly increased muscle strength
- 15-PGDH aggregates define target fibers in human neurogenic myopathies
Mechanistic Context
The detrimental effects of elevated 15-PGDH in aging contrast with its role in cancer, where it functions as a tumor suppressor 6. This creates an important clinical distinction: while 15-PGDH downregulation may promote certain cancers, its elevation during normal aging drives tissue degeneration and functional decline.
The age-related increase in PGE2 production (which would be suppressed by high 15-PGDH) is actually part of a compensatory inflammatory response. While chronic inflammation is generally harmful, the studies demonstrate that maintaining adequate PGE2 signaling through 15-PGDH inhibition provides net benefit for tissue regeneration and function in aged individuals 3, 5, 4.
Clinical Implications
15-PGDH represents a validated therapeutic target for countering sarcopenia, osteoarthritis, and neurogenic muscle weakness in older adults. Small-molecule inhibitors of 15-PGDH have demonstrated efficacy across multiple aging-related pathologies without requiring supraphysiologic prostaglandin levels—they simply restore more youthful PGE2 concentrations 3, 5, 4.