Figure 5. Inhibitory effect of resveratrol on TGFβ/Smad3-stimulated KLF5 protein production in vitro.

Rat aortic SMCs were infected with AdGFP (control) or AdSmad3 followed by pre-incubation with vehicle (DMSO) or resveratrol (50 μM) for 2 h, and then treated with solvent or TGFβ1 (5 ng/mL) for 24 h. Cells were then collected for Western blotting analysis (A) or RT-PCR (B). Microarray data were retrieved from our recent report²². Quantification: mean ± SEM of three independent experiments; normalization to β-actin; **P < 0.05 compared to any of the first 3 conditions; ^#P < 0.05 compared to AdSmad3 + TGFβ1 without pre-incubation with resveratrol. To determine the effect of KLF5 knockdown on TGFβ/Smad3-stimulated SMC de-differentiation, rat aortic SMCs were infected with AdGFP (control) or AdSmad3 and then transfected with scrambled or KLF5-specific siRNA for 6 h followed by treatment with solvent (control) or TGFβ1 (5 ng/mL) for 24 h. Cells were then used for Western blotting of KLF5 (C), calponin (D) or SM-MHC (E), or staining with Calcein for cell area measurement (F). Quantification: mean ± SEM of three independent experiments; normalization to β-actin; *P < 0.05 compared to AdSmad3 + TGFβ1 with scrambled siRNA (the middle bar).