Osteoarthritis Mechanisms and Biomarkers in Equine Models

Osteoarthritis in horses is a multifaceted degenerative joint disease characterised by progressive cartilage breakdown, subchondral bone remodelling and synovial inflammation. Equine models replicate human joint biomechanics and cartilage structure, making them invaluable for elucidating pathophysiological pathways and for validating candidate biomarkers. Key mechanisms include dysregulation of matrix metalloproteinases, altered cytokine profiles and changes in extracellular vesicle cargo within synovial fluid and plasma. Advances in proteomic and multi-omic analyses have revealed time-dependent shifts in synovial fluid constituents that correlate with disease stages, while novel neo-epitopes derived from cartilage and bone matrix proteins show promise for early detection. Improved understanding of these molecular events offers translational potential, guiding the development of targeted therapeutics, refining diagnostic assays and informing management strategies to mitigate soundness issues in sport horses and reduce economic losses worldwide.

Research from Nature Portfolio

Investigation of synovial fluid from horses with naturally occurring osteoarthritis has uncovered a marked decrease in larger hyaluronic acid–containing extracellular vesicles in affected joints. Quantitative imaging and nanoparticle tracking analyses demonstrated that both the number and proportion of these vesicles decline with increasing osteoarthritic grade, paralleling reductions in total hyaluronan concentration. These findings identify hyaluronic acid–laden vesicles as a novel fluid biomarker, reflecting joint homeostasis and offering a potential tool for early disease assessment and monitoring of therapeutic efficacy.

Osteoarthritis Mechanisms and Biomarkers in Equine Models publication trend

The graph below shows the total number of articles in osteoarthritis mechanisms and biomarkers in equine models across all publications each year (not limited to Nature Index journals).

Technical terms

Extracellular vesicles (EVs): Membrane-bound nanoparticles released by cells, carrying proteins, lipids and nucleic acids that mediate intercellular communication.

Neo-epitope: A novel antigenic site generated by protein cleavage, serving as a specific marker of tissue degradation.

Synovial fluid: Viscous joint fluid that provides lubrication, nutrient transport and removal of metabolic waste in articular cartilage.

Proteomics: Large-scale study of the entire set of proteins expressed in a biological sample, enabling identification of disease-related changes.

Matrix metalloproteinases (MMPs): A family of zinc-dependent enzymes responsible for degradation of extracellular matrix components during tissue remodelling and disease.

Subchondral bone: The layer of bone immediately beneath the cartilage surface, whose structural and biochemical changes influence joint health.

Mesenchymal stem cells (MSCs): Multipotent stromal cells capable of differentiating into cartilage-forming cells and secreting bioactive factors with regenerative potential.

References

1. Counts of hyaluronic acid-containing extracellular vesicles decrease in naturally occurring equine osteoarthritis. Scientific Reports (2022).
2. Multi-Omic Temporal Landscape of Plasma and Synovial Fluid-Derived Extracellular Vesicles Using an Experimental Model of Equine Osteoarthritis. International Journal of Molecular Sciences (2023).
3. Biglycan neo-epitope (BGN262), a novel biomarker for screening early changes in equine osteoarthritic subchondral bone. Osteoarthritis and Cartilage (2022).
4. Characterization of the Proteins Secreted by Equine Muscle-Derived Mesenchymal Stem Cells Exposed to Cartilage Explants in Osteoarthritis Model. Stem Cell Reviews and Reports (2022).