Fig. 2.

Src suppression increases PPARγ-mediated FABP4 expression. (a) Induced expression of FABP4 mRNA upon PPARγ activation. Basal expression of FABP4 and PPARγ was determined using immunoblot assay in A549, H2347, H1993 and Calu6 cells (left). Using RT-PCR assay, FABP4 mRNA induction was evaluated in PPARγ-negative cells (H1299) and PPARγ-positive cells (A549, H1993, Calu6) treated with DMSO or 10 μM of pioglitazone for 24 h (right). (b) FABP4 expression upon PPARγ activation or Src inhibition in HBEC-C1-PPARγ cells. HBEC-C1-PPARγ cells were treated with tetracycline overnight, followed by 10 μM of pioglitazone or 5 μM of SU6656 treatment for 24 h. QPCR (upper) and immunoblot (lower) assays were performed to determine FABP4 expression. (c) FABP4 expression in H1299 cells with PPARγ overexpression. H1299 cells were transfected with empty vector or PPARγ and followed by 5 μM of SU6656 treatment for 24 h. Data represent mean ± SEM of triplicates. Similar results were observed in at least two independent experiments. Asterisks refer to ***P ≤ 0∙001; ****P ≤ 0∙001 (Student's t-test (a) and one-way ANOVA, Tukey's post test (b,c)). In all RT-PCR data, y-axis represents fold change in gene expression.