The effect of endogenous glucocorticoids +/- 11β-hydroxysteroid dehydrogenase (11β-HSD) enzyme inhibitor on DKK1 expression. (A) Effect of various glucocorticoids on DKK1 mRNA expression in synovial fibroblasts (FLS). Cortisone caused a significant increase in DKK1 mRNA, an effect blocked by the 11β-HSD1 inhibitor glycyrrhetinic acid (GE). (B) Effect of glucocorticoids on DKK1 protein secretion in FLS and dermal fibroblasts (DF). (C) Sensitisation of DKK1 secretion by FLS to the effects of cortisone (E) by pretreatment with TNFα for 48 hours. *P < 0.05, **P < 0.01 relative to control. Results shown are the combined duplicates of four separate FLS lines.
Hardy et al. Arthritis Research & Therapy 2012 14:R226 doi:10.1186/ar4065