Abstract
Purpose: :
To investigate the expressions of Glucocorticoid Receptor alpha(GRα) and beta (GRß) messenger RNA (mRNA) and the effects of dexamethasone (DEX), IL–6 and IFN–γ on orbital fibroblasts (OF) from thyroid associated ophthalmopathy (TAO).
Methods: :
Cultured human OF from orbital connective tissue and extraocular muscle of ten TAO patients and ten control subjects were incubated with DEX(10–5,10–6,10–7,10–8,10–9M/L),IL–6(30,100,300U/ml) or IFN–γ (30,100,300U/ml) alone or incubated with DEX(10–6 M/L) and IL–6 or IFN–γ (300U/ml) for 24,48,72 and 96 hours. Total RNA of OF was extracted and reversely transcripted into cDNA. The expression of GRα and GRß mRNA was detected by means of fluorescent quantitative polymerase chain reaction (FQ–PCR).
Results: :
Expression of GRα and GRß mRNA were similar in cultured OF from both TAO patients and the control subjects. Incubation of OF with increasing concentrations of DEX (10–8∼10–6M/L) for 48h resulted in reduced GRα expression and unaffected GRß expression. GRα and GRß mRNA expression demonstrated no change after incubation with IFN–γ or IL–6.
Conclusions: :
There were no difference of GR gene expression between OF from TAO patients or the control subjects. GRα mRNA expression in OF were down–regulated by glucocorticoid, which may be one of the causes of glucocorticoid insistence.
Keywords: autoimmune disease • gene/expression • pathology: experimental