Fig. 2. mRNA expression of osteoblasts marker genes in MC3T3E1 cells (A, B) and C3H10T1/2 cells (C, D). Gene expression for osteocalcin (OCN) and runt-related transcription factor 2 (RUNX2) were evaluated by quantitative polymerase chain reaction. The expression level of each gene was normalized to that of β-actin. All data were shown as mean±SEM. Pio, pioglitazone; Rosi, rosiglitazone; Lobe, lobeglitazone. ^aP<0.001 vs. non-differentation; ^bP<0.05; and ^cP<0.001 compared to osteogenesis.