Investigation of synovial fluid lubricants and inflammatory cytokines in the horse: a comparison of recombinant equine interleukin 1 beta-induced synovitis and joint lavage models.
Authors: Watkins Amanda, Fasanello Diana, Stefanovski Darko, Schurer Sydney, Caracappa Katherine, D'Agostino Albert, Costello Emily, Freer Heather, Rollins Alicia, Read Claire, Su Jin, Colville Marshall, Paszek Matthew, Wagner Bettina, Reesink Heidi
Journal: BMC veterinary research
Summary
# Editorial Summary Lameness from joint inflammation remains the leading cause of performance loss in equine athletes, yet studying early inflammatory changes in living horses has been hampered by the scarcity of suitable experimental models. Researchers compared two established approaches—injecting recombinant interleukin-1 beta (IL-1β) into the carpus versus mechanically lavaging the tarsus—to characterise how synovial fluid composition and lubricating capacity changes during joint disease. The IL-1β model produced more pronounced inflammatory cytokine responses and greater reductions in lubricin and hyaluronic acid (key molecules essential for joint lubrication and load distribution) compared to lavage alone, with specific quantification of these molecular changes across serial sampling points revealing the distinct inflammatory profiles each model generates. These findings have direct implications for selecting appropriate research models when investigating novel therapeutic interventions, and highlight that mechanical trauma and chemical inflammation trigger measurably different patterns of synovial fluid degradation—information that should inform how practitioners anticipate and manage inflammatory joint disease progression in their own clinical cases.
Read the full abstract on PubMed
Practical Takeaways
- •Understanding inflammatory markers and lubricant changes in early synovitis may help identify biomarkers for early joint disease detection and monitoring in lame horses
- •Different joint insult mechanisms (cytokine-induced vs. mechanical lavage) produce distinct synovial fluid inflammatory profiles, suggesting different therapeutic targets may be needed
- •Serial synovial fluid analysis could potentially guide treatment decisions in managing joint inflammation and preserving articular cartilage
Key Findings
- •IL-1β-induced synovitis and joint lavage models produced different temporal patterns of inflammatory cytokine expression in synovial fluid
- •Synovial fluid lubricants (lubricin/proteoglycan 4 and hyaluronic acid) showed distinct responses between the two inflammatory models
- •Both models demonstrated early inflammatory and biophysical changes in synovial fluid relevant to joint disease pathogenesis
- •Non-terminal experimental models can be used to study serial changes in synovial fluid composition during acute joint inflammation