Comparison of Tenocyte Populations from the Core and Periphery of Equine Tendons

Tendon is a highly
organized, dense connective tissue that has
been demonstrated to have very little turnover. In spite of the low
turnover, tendon can grow in response to loading, which may take place
primarily at the periphery. Tendon injuries and recurrence of injuries
are common in both humans and animals in sports. It is unclear why
some areas of the tendon are more susceptible to such injuries and
whether this is due to intrinsic regional differences in extracellular
matrix (ECM) production or tissue turnover. This study aimed to compare
populations of tenocytes derived from the tendon core and periphery.
Tenocytes were isolated from equine superficial digital flexor tendons
(SDFTs), and the proliferation capacity was determined. ECM production
was characterized by immuno- and histological staining and by liquid
chromatography-mass spectrometry-based proteomics. Core and periphery
SDFT cultures exhibited comparable proliferation rates and had very
similar proteome profiles, but showed biological variation in collagen
type I deposition. In conclusion, the intrinsic properties of tenocytes
from different regions of the tendon are very similar, and other factors
in the tissue may contribute to how specific areas respond to loading
or injury.