Fig. 2

Leptin secretion and leptin receptor (Ob-R) expression were induced by prednisolone and aldosterone through glucocorticoid receptor (GR) signaling. Human osteoarthritis (OA) synovial fibroblasts were pre-incubated or not for 1 h with a GR inhibitor (mifepristone) or mineralocorticoid receptor (MR) inhibitors (eplerenone and spironolactone) and were then stimulated for 5 days with a glucocorticoid (prednisolone) (A) or mineralocorticoid (aldosterone) (B, C). Leptin expression was measured in cell culture supernatants by ELISA. Ob-R and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression in whole-cell extracts were analyzed by western blotting. Upper panels (right), quantification results of western blots shown in bottom panels. Proteins levels were normalized to GAPDH. Graphs represent mean +/- SD (n = 3 or 4 patients). Significance set at p < 0.05. b*Significantly different from a; c*significantly different from b; d not significantly different from b. kD kiloDalton