Zonal characterization and differential trilineage potentials of equine intrasynovial deep digital flexor tendon-derived cells.
Authors: Quam Vivian G, Altmann Nadine N, Brokken Matthew T, Durgam Sushmitha S
Journal: BMC veterinary research
Summary
Intrasynovial injuries to the deep digital flexor tendon (DDFT) carry a particularly poor prognosis in horses, frequently contributing to navicular disease and chronic lameness. Understanding the cellular properties of different zones within the fibrocartilaginous DDFT is essential for developing cell-based regenerative therapies, yet limited characterisation exists; Quam and colleagues therefore isolated and compared cells from the fibrocartilaginous and tendinous zones of the equine DDFT within the podotrochlear bursa, assessing their mesenchymal stem cell markers via flow cytometry and evaluating their baseline gene expression and trilineage differentiation potential using quantitative PCR and standard osteogenic, chondrogenic and tenogenic protocols. The fibrocartilaginous zone demonstrated distinct cellular characteristics compared to the tendinous zone, including differential expression of tenogenic, osteogenic and chondrogenic markers at baseline and divergent capacities for lineage-specific differentiation, with cells from each zone showing zone-specific developmental preferences. These zonal differences have significant implications for cell-based therapeutic approaches to DDFT injury: selecting cells from the appropriate anatomical zone or tailoring differentiation protocols to zone-specific biology may substantially improve healing outcomes and reduce the reinjury rates that currently plague DDFT cases in equine practice. The findings also offer translational value for managing fibrocartilaginous tendon injuries across species, providing a framework for optimising regenerative medicine strategies beyond equine applications.
Read the full abstract on PubMed
Practical Takeaways
- •DDFT cells show distinct regional properties that may influence how they respond to injury and regenerative therapies — understanding these differences is important for optimizing cell-based treatment approaches for intrasynovial tendon injuries
- •The fibrocartilaginous zone of the DDFT has unique cellular characteristics that may explain why this region is particularly prone to injury and why DDFT lesions associated with navicular disease have poor healing outcomes
- •Future cell-based therapies targeting DDFT injuries may need to account for zonal differences in cell populations to maximize healing potential and reduce reinjury rates
Key Findings
- •Fibrocartilaginous and tendinous zones of equine DDFT show differential mesenchymal stem cell marker expression via flow cytometry analysis of CD 29, CD 44, and CD 90
- •Tendon-derived cells from both DDFT zones demonstrate zone-specific basal expression of tenogenic, osteogenic, and chondrogenic markers as assessed by qRT-PCR
- •Trilineage differentiation capacity differs between fibrocartilaginous zone-derived cells (fTDC) and tendinous zone-derived cells (tTDC) in third passage cultures