Fig. 7
PPAR-γ gene over-expression suppresses the expression of ET-1 mRNA and protein. A549 cells were transfected with PPAR-γ plasmid or control vectors (negative control) using LipofectamineTM 2000 reagent and incubated at 37 °C for 24 h in an incubator containing 95 % air, 5 % CO2 and full humidity. The cells were then treated with 10 ng/mL TGF-β1 and the samples were analyzed by real-time qPCR, ELISA and western blotting. The results of real-time qPCR showed that the relative PPAR-γ mRNA level (normalized to GAPDH mRNA) in PPAR-γ transfection group was significantly increased than those in control group (a) and ET-1 mRNA level was significantly decreased (b) (*p < 0.05). The increased ET-1 mRNA level (b) and protein concentration (c) mediated by TGF-β1 was suppressed by transfection of PPAR-γ plasmid. Western blotting showed that PPAR-γ gene over-expression decreased the expression of phospho-P38 and phospho-Smad2 (d). The results are presented as means ± SD of 3 independent experiments. (NC, negative control group; PPARγ, PPAR-γ plasmid transfection group; TGF, TGF-β1 group; PPARγ + TGF, PPAR-γ plasmid transfection + TGF-β1 group)