FIGURE 2.

Knockdown of Smad2 or Smad3 enhances PAI-1 induction after TGF-β1 stimulation. HKC-8 cells were transiently transfected with control (Cont.) siRNA, Smad2, or Smad3 siRNA (120 nm) and then treated with different doses of TGF-β1 as indicated. Whole cell lysates were immunoblotted with specific antibodies against PAI-1, Smad2, Smad3, phospho-Smad2, phospho-Smad3, and GAPDH, respectively. Representative Western blots (A and C) and the relative abundance of PAI-1 after normalization with GAPDH (B and D) are presented. The data (relative to the controls = 1.0) are presented as the means ± S.E. of three experiments. *, p < 0.05; **, p < 0.01 versus controls. †, p < 0.01 versus control siRNA group with TGF-β1.