FIG. 6.

Differentiation capacity of IRS-1-deficient cells is improved by overexpression of PPARγ or C/EBPα. IRS-1 KO cell lines overexpressing PPARγ (KO + PPARγ) or C/EBPα (KO + C/EBPα) were prepared as described in Materials and Methods. Furthermore, IRS-1-deficient cells were treated with 50 μM troglitazone (KO + Tro) throughout the differentiation process. At day 6 of differentiation, cells were either stained with oil red O (A) or prepared for Western blot analysis of various adipogenic markers as shown (B). Results are representative of at least two independent experiments.