Glucocorticoids suppress proteoglycan production by human tenocytes

• Published in: Acta orthopaedica Vol. 76; no. 6; pp. 927 - 931
• Main Authors: Wong, Margaret Wan Nar, Tang, Yvonne Yin Nei, Lee, Simon Kwong Man, Fu, Bruma Sai Chuen
• Format: Journal Article
• Language: English
• Published: Basingstoke Taylor & Francis 01.12.2005
• Subjects: Biological and medical sciences; Bones, joints and connective tissue. Antiinflammatory agents; Cells, Cultured; Dexamethasone - adverse effects; Dexamethasone - pharmacology; Diseases of the osteoarticular system; Glucocorticoids - adverse effects; Glucocorticoids - pharmacology; Humans; Injuries of the limb. Injuries of the spine; Medical sciences; Patella; Pharmacology. Drug treatments; Proteoglycans - biosynthesis; Tendon Injuries - chemically induced; Tendons - cytology; Tendons - drug effects; Traumas. Diseases due to physical agents; Human; Proteoglycan; Corticosteroid; Cell culture; Incorporation; Dexamethasone; Steroid hormone; Spontaneous; Antiinflammatory agent; Explant; Glucocorticoid; In vitro; Assay; Regulation(control); Treatment; Patella; Adrenal hormone; Risk factor; Production; Tissue rupture; Reversibility; Triamcinolone; Platelet derived growth factor; Tendon
• ISSN: 1745-3674; 1745-3682
• DOI: 10.1080/17453670610046118

Background The role of glucocortiocid injection therapy in spontaneous tendon rupture is controversial. We hypothesized that glucocorticoids suppress proteoglycan production in tendon and studied the in vitro effects of dexamethasone and triamcinolone on proteoglycan production by cultured human tenocytes. Material and methods We obtained primary cultures of human tenocytes from explants of healthy human patellar tendon. The human tenocytes were treated with 1 μM dexamethasone or 1 μM triamcinolone. The amount of proteoglycan production was measured by 35 S-sulfate incorporation assay and compared with control cultures. The reversibility of the effect of dexamethasone by co-incubation with 10 ng platelet-derived growth factor (PDGFBB) was also tested. Results Treatment with 1 μM triamcinolone reduced the amount of 35 S-sulfate incorporation to 80% of control cultures (p = 0.007), whereas 1 μM dexamethasone reduced it to 72% (p = 0.01). Co-incubation of 10 ng/mL PDGFBB with 1 μM dexamethasone returned the 35 S-sulfate incorporation to a level thatwas significantly higher than for dexamethasone treatment alone (108%; p = 0.01). Interpretation Glucocorticoids suppressed proteoglycan production in cultured human tenocytes. The suppression by dexamethasone was reversed by simultaneous addition of PDGFBB. Suppressed proteoglycan production may affect the viscoelastic properties of tendon and increase the risk of spontaneous rupture.   ▪