FIGURE 1.

A, regulated expression of FOX transcription factors during adipogenesis. 3T3-L1 cells were induced to differentiate into adipocytes, and RNA was prepared at the indicated times and analyzed by real time PCR for Foxa1, Foxc2, Foxf2, Foxo1, and Foxp1. The data are representative of at least two independent experiments. The data are presented as percentages of maximum expression observed. B, ectopic expression of FOXC2 blocks adipogenesis in vitro. 3T3-L1 preadipocytes were infected with a retrovirus vector alone (pLNCX2) or retrovirus carrying the gene for FOXC2. Two days post-confluence, the cells were induced to differentiate with MDI and were stained with Oil Red-O at day 14. The cells were lysed at the indicated times for immunoblot analyses of C/EBPα, FABP4, and C/EBPβ ((LAP2)). These results are representative of at least three independent experiments. C, C/EBPα and PPARγ partially rescue adipocyte differentiation of FOXC2-expressing cells. Control (pLNCX2) or FOXC2-expressing cells were reinfected with a retrovirus vector alone (pBabe) or retroviruses carrying the genes for C/EBPα or PPARγ and were co-selected with G418 and puromycin. Two days post-confluence, the cells were induced to differentiate with MI. At day 10, the cells were photomicrographed. D, ectopic expression of Foxf2 promotes adipogenesisinvitro.3T3-L1 preadipocytes were infected with a retrovirus vector alone (pLXSN) or retrovirus carrying the gene for Foxf2. Two days post-confluence, the cells were induced to differentiate with MI. The cells were lysed at the indicated times for immunoblot analyses of C/EBPβ (LAP2 and LIP), FABP4, and C/EBPα. These results are representative of at least three independent experiments.