Figure 1.

Leptin suppresses the effects of PPARγ on chondrogenic differentiation and chondrocyte hypertrophy in growth plate chondrocytes. ((a), (b)) Quantitative real-time RT-PCR analysis of Col2a1 (a) and aggrecan (b) mRNA expression in chondrocytes treated with ciglitazone and/or leptin for 5 days. *P < 0.05 versus the expression in control cells. **P < 0.05 versus the expression in the cells treated with ciglitazone alone. (c) Alcian blue staining of growth plate chondrocytes in monolayer cultures after 5 days of treatment with ciglitazone and/or leptin. ((d), (e)) Expression of Col10a1 mRNA expression (d) and alkaline phosphatase activity (e) of growth plate chondrocytes treated with ciglitazone and/or leptin for 5 days. *P < 0.05 versus the cells treated with T3 alone. **P < 0.05 versus the chondrocytes treated with both T3 and ciglitazone. (f) Alkaline phosphatase staining of chondrocytes cultured in monolayer and treated with ciglitazone and/or leptin for 5 days.