Treatment Effects of Intra-Articular Allogenic Mesenchymal Stem Cell Secretome in an Equine Model of Joint Inflammation.
Authors: Kearney Clodagh M, Khatab Sohrab, van Buul Gerben M, Plomp Saskia G M, Korthagen Nicoline M, Labberté Margot C, Goodrich Laurie R, Kisiday John D, Van Weeren P R, van Osch Gerjo J V M, Brama Pieter A J
Journal: Frontiers in veterinary science
Summary
# Editorial Summary Mesenchymal stem cell (MSC) secretomes—the bioactive substances released by these cells—represent an intriguing alternative to cell-based therapies for joint inflammation, offering potential advantages as an off-the-shelf product without the complexities of cell viability and storage. Clodagh Kearney and colleagues investigated whether intra-articular injection of allogeneic MSC secretome could reduce inflammation in equine radiocarpal joints, using a lipopolysaccharide (LPS) model to induce acute synovitis in eight horses and comparing secretome-treated joints against both untreated controls and, in a second phase, against whole MSC preparations. The secretome demonstrated measurable anti-inflammatory effects in phase 1, with joint circumference significantly lower at 24 hours post-injection and peak synovial glycosaminoglycan (GAG) concentrations elevated at the same timepoint (p<0.001)—though the clinical significance of increased GAG release remains ambiguous, as this could reflect either cartilage protection or degradation. Phase 2 revealed comparable efficacy between secretome and intact MSC treatments, suggesting the secretome's therapeutic benefits derive from paracrine factors rather than the cellular machinery itself. For practitioners considering regenerative medicine protocols, these findings support investigating MSC secretome as a pragmatic alternative where cell-based therapy logistics present challenges, though the modest effect sizes and limited understanding of GAG dynamics in this acute model warrant cautious interpretation before broad clinical adoption.
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Practical Takeaways
- •MSC-secretome offers a promising off-the-shelf alternative to live cell MSC therapy for intra-articular joint inflammation, with comparable efficacy and easier storage/handling advantages
- •Peak anti-inflammatory effects appear within 24 hours of intra-articular injection, making this suitable for acute inflammatory episodes
- •While GAG changes suggest metabolic effects on cartilage, clinical significance remains unclear—monitor cartilage health outcomes in longer-term or clinical studies before widespread adoption
Key Findings
- •MSC-secretome treatment reduced joint circumference at 24 hours post-injection compared to medium control (p < 0.05)
- •MSC-secretome treatment increased peak synovial glycosaminoglycan (GAG) values at 24 hours post-injection (p < 0.001)
- •In direct comparison, MSC-secretome and whole MSC treatments produced comparable anti-inflammatory effects
- •MSC-secretome demonstrated clinical anti-inflammatory effects in the LPS-induced joint inflammation model