Abstract
Tendon is known to remodel its structure and alter mechanical properties in response to changes in its mechanical environment. Tendon cells, tenocytes, are thought to play significant roles in tendon tissue remodelling, by responding to mechanical stress. Like other adherent cells, tenocytes exert traction forces to their substrate when the cells attach to the substrate. Cell traction forces are thought to reflect the level of intracellular tension generated in actin cytoskeletons. It has been shown that intracellular tension level is a regulatory factor of tenocyte catabolism. Accordingly, the present study hypothesized that tenocyte response to interleukin-1β is dependent on the level of intracellular tension. Tenocytes, isolated from rabbit Achilles tendons, were seeded microfabricated, elastic micropillar substrates, and were subjected to the treatment of IL-1β at four different concentrations. It was demonstrated that tenocyte traction force level was dependent on the elastic modulus of micropillar substrates. In addition, cells on softer substrates were more prone to the stimulation of the catabolic agent, exhibiting a greater change in cell morphology. These results suggest that tenocytes with a low level of intracellular tension, which implies that the cells are catabolic, are stimulated by catabolic/inflammatory agents and further enhance their catabolism.
