Dexamethasone (dex)

DPSC and SHED were chemically induced to differentiate along chondrogenic, osteogenic, and adipogenic lineages by culturing monolayers of DPSC and SHED in specific differentiation medium for three weeks. Chondrogenic differentiation was induced using chondrogenic induction medium containing 20 ng Transforming growth factor beta-1 (TGFβ1) (Merck, Millipore), 10 ng insulin, 100 nM dexamethasone (Sigma-Aldrich, Inc., USA) and 100 μM ascorbic acid (Dae-Jung Chem and Metal Co, Korea). Cells were stained with 1% toluidine blue to detect extracellular matrix produced by chondrogenic derivatives. Osteogenic differentiation was induced by using osteogenic medium containing 0.1 μM dexamethasone (Serva, GmbH), 10 μM β-glycerophosphate (Sigma Chemical Corp, USA) and 50 μM ascorbate phosphate (Dae-Jung Chem and Metal Co, Korea). Cells were stained with Alizarin Red S stain (Sigma-Aldrich, Inc., USA) to visualize calcium deposition. Adipogenic differentiation was induced using adipogenic medium containing 0.5 μM isobutyl-methylxanthine (Sigma-Aldrich, Inc, USA), 1 μM dexamethasone (Serva, GmbH), 10 μM insulin (Sigma-Aldrich, Inc., USA), and 200 μM indomethacin (MP Biomedical). Cells were stained with Oil Red O (Sigma-Aldrich, Inc., USA) to determine presence of lipid droplets. Cells grown in regular media served as negative controls.