Figure 2. Effect of Trichostatin A (TSA) on expression of transforming growth factor β1 (TGFβ1)-related signal transduction in cultured human subconjunctival fibroblasts. A: western blotting indicates that at 2 h post-TGFβ1 addition TSA at concentrations of 200 nM faintly reduced the level of phosphorylated Smad2 (pSamd2) as compared with the phosphorylation level at 1 h post-TGFβ1 addition, while the cells maintained a similar level of phosphorylation of Smad2 until 2 h in the absence of TSA. TSA at a concentration of 500 nM obviously reduced its phosphorylation level at 2 h. Adding TSA upregulated the expression of Smad7 and TGIF in a dose-dependent manner. B: Immunocytochemistry also showed that TSA suppressed nuclear translocation of pSmad2. In the absence of TSA pSmad2 was detected in cell nuclei at 0.5 and 1.0 h post-TGFβ1 addition. With TSA at a concentration of 10 nM pSmad2 was detected in the nuclei after 0.5 h. TSA at the concentrations of 200 and 500 nM abolished its nuclear expression.