Fig. 1

Augmentation by mifepristone of upregulation of adiponectin expression during adipocyte differentiation in 3T3-L1 cells. A The experimental protocol used to examine the effect of treatment with vehicle (dotted line) and either mifepristone or pioglitazone (solid line) during the differentiation of 3T3-L1 cells to adipocytes. Adipocyte differentiation was induced as described in the Materials and Methods. MIX, the period of incubation with the first differentiation medium, containing 4.5 g/L D-glucose, 1 µg/mL insulin, 1 µM dexamethasone and 0.5 mM IBMX in the standard culture media. INS, the period of incubation with the second differentiation medium, consisting of 4.5 g/L D-glucose and 1 µg/mL insulin in the standard culture media. DMEM, the period of incubation with the standard culture media. B Representative microscopic images of Bodipy staining and summaries (n = 6) of the quantification on day 10 after induction of adipogenesis. Scale bar, 600 µm. C The time-dependent changes in the cell count during adipogenesis with and without 1 µM mifepristone. D Representative immunoblot images and summary (n = 4) showing the time course of changes in the adiponectin and Rac1 protein expression during adipogenesis with and without treatment with 1 µM mifepristone. The levels of adiponectin were normalized by those of Rac1, and the value obtained without mifepristone treatment on day 8 was assigned a value of 1. E Summary (n = 6) of the qRT-PCR analysis of the expression of adiponectin, Fabp4, PPARγ and PPARγ2 mRNA on day 5. The level of each transcript was normalized to that of 18S rRNA, and the value obtained without treatment was assigned a value of 1. F Representative Immunoblot (IB) images and summary (n = 4) of the concentration-dependent effects of treatment with mifepristone or pioglitazone on the adiponectin protein expression on day 5. The expression levels of adiponectin were normalized to those of Rac1, and then expressed as the fold increase from the value obtained without treatment. All data represent the mean ± S.E.M. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 vs. Day 0 (B) or the values obtained without treatment (C, D). †P < 0.05; ††††, P < 0.0001 vs. vehicle. ns, not significantly different