The effect of fetal bovine serum (FBS) and human AB serum (HS) on PPARγ response. (A,B) Transcript levels of FABP4 were determined by qRT-PCR. The indicated samples were cultured in fetal bovine serum (FBS)– or human AB serum (HS)–containing cell-cultured medium. (A) RNA was isolated at the indicated times; cells were treated with 1 μM rosiglitazone (RSG; 6 hours, 24 hours DC) or with 2.5 μM RSG (5 days DC). (B) Cells were cultured for 24 hours and treated with 1 μM rosiglitazone (RSG) and/or with 5 μM GW9662 (ANT). (C) Western-blot analysis of FABP4 protein expression in DCs. GAPDH was used as a loading control. Cells were cultured for 24 or 48 hours and treated with 1 μM rosiglitazone (RSG) and/or 5 μM GW9662 (ANT). Samples were cultured in fetal bovine serum (FBS)– or human AB serum (HS)–containing cell-cultured medium. (D) COS1 cells were cotransfected with MH100-TK-Luciferase reporter construct and GAL4-PPARγ–LBD or GAL4-PPARδ–LBD construct along with β-galactosidase construct. Cells were lysed after 24 hours, and the luciferase and β-galactosidase activity was assayed as described in “Transient transfections and reporter gene assays.” All experiments were done in triplicates; error bars represent SDs. Cell were treated with 1 μM (-6) or 100 nM (-7) PPARγ activator (RSG) or 1 μM (-6) or 100 nM (-7) PPARδ activator (GW501516 abbreviated as GW1516). The indicated cells were cultured in 10% or 5% human AB serum (HS)–containing medium.