Evaluation of the Catabolic and Anabolic Gene Expression Effects and Histology Changes induced by Platelet-Rich Gel Supernatants in Equine Suspensory Ligament Explants Challenged with Lipopolysaccharide
Authors: C. Castillo-Franz, C. López, J. Carmona
Journal: Muscles, ligaments and tendons journal
Summary
# Editorial Summary Suspensory ligament desmopathy remains a significant challenge in equine practice, and whilst platelet-rich plasma (PRP) products have gained clinical traction, evidence explaining their mechanisms of action—particularly regarding leukocyte content—has been limited to in vitro work. Castillo-Franz and colleagues cultured equine suspensory ligament tissue explants from six horses with lipopolysaccharide (to simulate inflammatory insult) and compared responses to two PRP-derived supernatants: one leukocyte-rich and one leukocyte-reduced, each at 25% and 50% concentrations, measuring gene expression of inflammatory and matrix remodelling markers alongside histological changes over 72 hours. The leukocyte-reduced formulation at 25% concentration proved most effective, up-regulating anabolic genes (type 1 collagen, decorin, and TGF-β1) whilst the leukocyte-rich variant more effectively suppressed catabolic enzymes (MMP3 and MMP13); both formulations suppressed the inflammatory transcription factor NFκB. Their findings suggest that promoting ligament matrix synthesis may be more therapeutically valuable than simply blocking degradation, and that lower leukocyte concentrations alongside lower treatment doses optimise biological outcomes in suspensory ligament tissue. Whilst these in vitro results are promising and support the safety and cost-effectiveness profile of PRP treatments, clinical validation in live animal and human models is essential before drawing definitive conclusions about optimal treatment protocols for equine desmopathy.
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Practical Takeaways
- •Leukocyte-reduced PRP products may be preferable to leukocyte-rich formulations for treating suspensory ligament injuries based on superior gene expression profiles for collagen synthesis
- •In vitro evidence suggests PRP's benefit comes primarily from stimulating new matrix protein production rather than just blocking breakdown—this distinction could inform treatment timing and rehabilitation protocols
- •These findings require in vivo validation before clinical recommendations; current evidence is laboratory-based and does not yet confirm clinical efficacy in horses
Key Findings
- •Leukocyte-reduced PRGS at 25% concentration upregulated collagen type 1, decorin, and TGF-β1 expression in LPS-challenged ligament explants
- •Leukocyte-concentrate PRGS at 25% showed greater MMP3 and MMP13 downregulation compared to other hemoderivatives
- •All PRGS formulations produced NFκB downregulation, indicating anti-inflammatory effects
- •Leukocyte-reduced PRGS at 25% showed superior histological appearance and may promote ligament healing through anabolic rather than purely anti-catabolic mechanisms