Glucocorticoids inhibit tenocyte proliferation and Tendon progenitor cell recruitment

Abstract

Corticosteroid injection is commonly used to treat tendon injuries but is often associated with tendon rupture and impaired tendon healing. The effects of dexamethasone on tenocytes have been studied in vitro but only using high concentrations of dexamethasone in monolayer cultures of tenocytes over short periods of time. We have therefore investigated the effects of physiological and pharmacological concentrations of dexamethasone on monolayer cultures of tenocytes over extended time periods. We have also used fibroblastic-colony forming unit cultures to examine the effects of dexamethasone on a progenitor cell population located in tendons. Culturing tenocytes in the presence of dexamethasone for a period of 24 days resulted in a concentration-related decrease in cell number and collagen synthesis as compared to control cultures. This effect was time dependent with cell number in both dexamethasone-treated and control cultures leveling off after 14 days with the control cultures reaching higher cell densities. In contrast in control cultures, collagen accumulation continued to increase until week 4, whereas in the presence of dexamethasone, this tended to level off after 14 days. To study the role of progenitor cell recruitment, the effects of dexamethasone were investigated using the fibroblastic-colony forming unit assay. Treatment with dexamethasone at concentrations of 0.1 nM to 10 mM leads to a progressive reduction in mean colony size as compared to control cultures. Colony number remained constant at concentrations below 10 nM but fell progressively at concentrations above this. In conclusion, dexamethasone reduces both cell number and collagen synthesis in tenocyte cultures in a concentration-dependent manner by both direct effects on tenocyte proliferation and collagen accumulation, and also by modulating the recruitment of tendon progenitor cells. ß

Synergistic effects of dexamethasone and quinolones on human-derived tendon cells

“…Moreover, reduced expression of collagen type I mRNA and procollagen type I and II was shown in two studies with tenocytes of chick embryos [35,36]. A concentration-dependent reduction in the number of tenocytes and collagen synthesis was also detected with rat tail tenocytes when exposed over extended time periods [37].…”

Eccentric training as a new approach for rotator cuff tendinopathy: Review and perspectives

“…It is important to highlight that the rest and anti-inflammatory are mainly used for the symptomatic relief with no direct effect in the tendinopathy as chronic tendon disorders are predominantly degenerative. Further, both non steroidal antiinflammatory drugs [91] and corticosteroid drugs [92,93] could have deleterious effects on long-term tendon healing.…”

In vitro study comparing two collageneous membranes in view of their clinical application for rotator cuff tendon regeneration

“…31 Many studies have demonstrated that the administration of corticosteroids in cell cultures from tendons affect tenocyte viability, proliferation, collagen type I synthesis, and migration. 12,13,32,33 In the present study, we used a more similar model to the clinical situation, and instead of administering corticosteroids to cells in culture, we isolated tenocytes from the tendons of animals previously submitted to pharmacological therapy.…”