(A and B) Wild-type or mutant C/EBPβ were ectopically expressed in 3T3-L1 cells, as indicated, which induces spontaneous differentiation of the cells in the absence of MDI. The expression of Pparg and Fabp4 was determined by RT-qPCR performed 4 days post-transfection. Results for Cebpb are shown to confirm equal ectopic expression of the mutants.
(A) Mutation of PARP-1-dependent sites of PARylation in C/EBPβ enhances adipogenesis. Bars marked with different letters are statistically different from each other (ANOVA; p-value < 0.05). (B) PARylation site C/EBPβ mutants are resistant to the effects of PARP inhibitor. The cells were treated ± 20 µM BYK204165 (1 hour pretreatment, followed by 4 days of treatment after adding MDI). Bars marked with an asterisk are statistically different from the corresponding control (Student’s t-test; p-value < 0.05).
(C) Model for the role of PARP-1 in attenuating adipogenesis, as described in the text.