Figure 4.
Forced expression of C/EBPβ (LAP) in C/EBPβ(−/−) MEFs restores both MCE and the capacity for differentiation. C/EBPβ(−/−) MEFs were maintained in DMEM containing 10% FBS until 2 days postconfluence and then infected with wt C/EBPβ (LAP), C/EBPβ (LIP), or LacZ adenoviral expression vectors 1 h before being subjected to the standard differentiation protocol. (A) Twenty-four hours later cell lysates were prepared, and 50 μg of protein were subjected to SDS/PAGE and immunoblotted with anti-C/EBPβ antibody. (B) Cell lysates were prepared on day 6 and subjected to immunoblotting with antibodies to C/EBPα, PPARγ, and 422/aP2. (C) On day 8 cells were fixed, stained with oil red O, and photographed.