Figure 4. The addition of FPP up-regulates PPARγ target genes and promotes de novo fatty acid synthesis.

(A–D) Expression levels of adipogenic marker genes, such as aP2 (A), LPL (B), adiponectin (C) and GLUT4 (D), in 3T3-L1 cells treated with or without FPP. 3T3-L1 cells were induced to differentiate with or without 0.01 μM/1 μM FPP or 5 μM Pio for 48 h. Total RNA was isolated and analysed by real-time monitoring RT–PCR. mRNA expression levels of each gene were normalized to the expression levels of the ribosomal 36B4 gene. The expression level of cells treated with the vehicle control is set at 100% and relative expression levels are presented as the fold inductions over the vehicle control. (E) Rate of de novo fatty acid synthesis from glucose after chronic FPP treatment during adipocyte differentiation. 3T3-L1 cells were induced to differentiate and maintained with or without 1 μM FPP or 1 μM Pio for 10 days. Cells were analysed using [¹³C₆]-glucose and the LC/MS system as described in the Materials and methods section. All of the values are means±S.E.M. for five or six tests. *P<0.05, **P<0.01 compared with vehicle controls.