TβRII mediates the TGF-β1-induced upregulation of GDNF and furin in SVOG cells. (A) SVOG cells were transfected for 48 h with the transfection reagent (iMAX), control siRNA (siCtrl; 25 or 50 nM) or TβRII siRNA (siTβRII; 25 or 50 nM), and the protein levels of TβRII were examined using Western blot analysis. (B,C) SVOG cells were transfected for 48 h with 25 nM siCtrl or 25 nM siTβRII and then treated with vehicle control or 1 ng/mL TGF-β1 for an additional 12 h (B) of 24 h (C). The mRNA (B) and protein (C) levels of GDNF were examined using RT-qPCR (B) and Western blot analysis (C), respectively. (D,E) SVOG cells were transfected for 48 h with 25 nM siCtrl or 25 nM siTβRII and then treated with vehicle control or 1 ng/mL TGF-β1 for an additional 12 h (D) of 24 h (E). The mRNA (D) and protein (E) levels of furin were examined using RT-qPCR (D) and Western blot analysis (E), respectively. The results are expressed as the mean ± SE of at least three independent experiments. Values with different lower-case letters are significantly different (p < 0.05). If a pair of values is significantly different (p < 0.05), the values have different subscript letters (a vs. b or b vs. c) assigned to them. siCtrl, control siRNA.