Fig. 5
Silencing of PPAR-γ silence on the expression of ET-1. A549 cells were transfected with PPAR-γ siRNA 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. Then transfected cells were treated with 10 ng/mL TGF-β1and the samples were collected and analyzed by real-time qPCR, ELISA and western blotting. The results of electrophoresis and real-time qPCR showed that PPAR-γ silencing reduced the expression of PPAR-γ mRNA (a, b) (*p < 0.05 while compared to NC). The results of RT qPCR (c) and ELISA (d) showed that PPAR-γ silencing slightly decreased the expression of ET-1 mRNA expression (p = 0.5206 while compared to NC) and increased the expression of ET-1 protein with no statistical significance (p = 0.0902 while compared to NC). The increased ET-1 mRNA level (c) and protein concentration (d) mediated by TGF-β1 was enhanced by transfection of PPAR-γ siRNA plasmid with statistical significance (*p < 0.05 while PPARsiRNA + TGF group compared to TGF group). Western blotting showed that PPAR-γ silencing increased the expression of phospho-p38 and phospho-Smad2 (e). The results are presented as means ± SD of 3 independent experiments. (NC, negative control group; PPARsiRNA, PPAR-γ silencing group; TGF, TGF-β1 group; PPARsiRNA + TGF, PPAR-γ silencing + TGF-β1 group)