Decoding the transcriptomic expression and genomic methylation patterns in the tendon proper and its peritenon region in the aging horse
Authors: M. Y. Pechanec, M. J. Mienaltowski
Journal: BMC Research Notes
Summary
# Editorial Summary: Tendon Ageing and Regional Gene Expression in Horses Equine tendons' notoriously poor healing capacity and high re-injury rates reflect underlying changes in gene expression and epigenetic regulation that vary across different tendon regions and age groups. Pechanec and Mienaltowski used RNA sequencing and DNA methylation analysis to compare the tendon proper and peritenon regions in adolescent, midlife, and geriatric horses, identifying region-specific gene expression patterns that persist regardless of age. The tendon proper maintained consistently elevated expression of structural genes including decorin (DCN), cartilage oligomeric matrix protein (COMP), fibronectin (FN1), and lysyl oxidase (LOX), whilst the peritenon showed higher activity of gelsolin (GSN) and AHNAK, suggesting distinct functional roles in matrix organisation and remodelling. Notably, gene activity peaked in adolescent and geriatric populations but dipped during midlife, whilst five genes (HAND2, CHD9, RASL11B, ADGRD1, and COL14A1) demonstrated both differential methylation and expression patterns across regions. These findings illuminate why aged tendons exhibit diminished repair potential and highlight that regional differences in epigenetic regulation may represent therapeutic targets for improving healing outcomes in geriatric horses or reducing re-injury risk in previously compromised tendons.
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Practical Takeaways
- •Understanding regional differences in tendon aging may explain why older horses have reduced healing capacity and help target therapies to specific tendon zones
- •The distinct molecular profiles of adolescent and geriatric tendons suggest different injury prevention and rehabilitation strategies may be needed for these age groups
- •Epigenetic modifications in aging tendons represent potential intervention points for improving healing outcomes in older horses with tendinopathy
Key Findings
- •Transcriptomic and epigenetic differences exist between tendon proper and peritenon regions across adolescent, midlife, and geriatric horses
- •Tendon proper maintains elevated expression of structural genes (DCN, COMP, FN1, LOX) while peritenon expresses distinct genes (GSN, AHNAK)
- •Adolescent and geriatric tendons show increased gene activity compared to midlife tendons, suggesting biphasic aging effects
- •Five genes (HAND2, CHD9, RASL11B, ADGRD1, COL14A1) demonstrate differential methylation and expression patterns between tendon regions