Figure 5.

Inhibition of purine biosynthesis blocks adipogenesis by downregulating the expression of key transcriptional regulators.A, Western blotting analysis of primary preadipocytes differentiated for 8 days after adding 6MP or MIZ at day 0 and then every other day, at day 2 and then every other day, or at day 4 and then every other day. Duplicate samples represent two biological replicates. B, cells were treated as in (A), and Oil Red O staining was performed. Statistical significance was determined using one-way ANOVA multiple comparisons test. Error bars indicate mean ± SD, ∗p ≤ 0.05, ∗∗p ≤ 0.01, ∗∗∗p ≤ 0.001, and ∗∗∗∗p ≤ 0.0001. C, MIZ and 6MP were added at the start of primary SVF differentiation. Cells were differentiated for 1, 2, or 4 days. C/EBPδ, C/EBPβ, PPARγ, C/EBPα, and tubulin were analyzed by Western blotting. Duplicate samples represent two biological replicates. D, 3T3-L1 cells stably expressing pBABE control vector or PPARγ2 were differentiated and treated with 25 μM MIZ or DMSO control for 6 days. Lysates were analyzed by Western blotting as indicated. The data are representative of three independent experiments. 6MP, 6-mercaptopurine; C/EBP, CCAAT/enhancer-binding protein; DMSO, dimethyl sulfoxide; MIZ, mizoribine; PPARγ, peroxisome proliferator–activated receptor γ.