FIG. 6.

SIRT1 regulates expression of the ER oxidoreductase Ero1-Lα. (A) 3T3-L1 preadipocytes were differentiated for the indicated days, and total cell RNA was extracted for RT-PCR analysis of mRNAs corresponding to PPARγ, C/EBPα, adiponectin, Ero1-Lα, FABP4/aP2, and GAPDH. (B and C) 3T3-L1 preadipocytes expressing a control vector (-) or a SIRT1 siRNA (+) were differentiated for 8 days for RT-PCR analysis of mRNAs (B) or for the indicated days for Western blot analysis of intracellular proteins (C). (D) Control and SIRT1 siRNA-expressing 3T3-L1 preadipocytes were differentiated in the absence (Con) or presence of either a PPARγ antagonist (Antag; 10 μM T0070907) or PPARγ agonist (Trog; 5 μM troglitazone), and the medium (extracellular) and total cell layer (intracellular) were harvested for Western blot analysis of the indicated proteins.