Proteomic profiling reveals the potential role of allogenic equine platelet-rich plasma and extracellular vesicles in modulating tendon inflammation and repair.
Authors: Emily J Clarke, Anders Jensen, Alexandra M Gillen, David Bardell, Mark Senior, James R. Anderson, Mandy J. Peffers
Journal: American journal of veterinary research
Summary
# Editorial Summary: Proteomic Analysis of Equine PRP and Extracellular Vesicles in Tendon Repair Tendon injuries remain a significant challenge in equine practice, and whilst autologous platelet-rich plasma (PRP) shows therapeutic promise, clinical outcomes vary considerably—a variability Clarke and colleagues attribute partly to inconsistent product composition. Their 2025 proteomic study characterised the protein profiles of equine PRP and PRP-derived extracellular vesicles (EVs), then evaluated how these preparations affected inflammatory tenocytes in vitro using mass spectrometry analysis. Compared to baseline plasma, both PRP and EVs were notably enriched in proteins governing cellular waste disposal and lipid metabolism inhibition; when applied to IL-1β and TNF-α-stimulated tenocyte fibroblasts, PRP and EVs altered 18 proteins, including a significant decrease in type I collagen abundance and an increase in sequestosome 1—a protein implicated in both autophagy-mediated resolution and inflammatory amplification. Understanding these molecular mechanisms—particularly the role of EV-mediated signalling in modulating tendon inflammation—could enable development of standardised, more efficacious PRP protocols, potentially reducing reinjury rates and improving healing outcomes across different clinical cases. For practitioners considering PRP therapy, this work highlights why composition matters and supports further investigation into EV-enriched preparations as a means of achieving more consistent and predictable results.
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Practical Takeaways
- •This research suggests PRP composition and its extracellular vesicles directly affect how tendon cells respond to injury — understanding this mechanism may help explain variable clinical outcomes with PRP treatment
- •The decrease in collagen production with PRP treatment warrants further clinical investigation to determine optimal timing and dosing to support rather than inhibit collagen synthesis during healing
- •Future PRP therapies could be standardized based on protein composition to improve consistency and effectiveness, potentially reducing tendon reinjury rates
Key Findings
- •PRP and PRP-derived extracellular vesicles were enriched in proteins related to cellular waste disposal and lipid metabolism inhibition compared to plasma
- •Treatment with PRP and PRP EVs decreased collagen type 1 α chain 1 abundance in inflammatory tenocytes, suggesting altered collagen metabolism
- •PRP EVs induced increased sequestosome 1 levels in tenocytes, with potential dual roles in either enhancing or resolving inflammation through autophagy
- •18 proteins in tenocyte fibroblasts were significantly influenced by PRP or PRP EV treatment under inflammatory conditions