Figure 6.

Small molecular inhibitors of SMAD1/5/9 modulate disturbed shear-induced EndMT in venous endothelial cells. (A) SMAD2/3 inhibition by 500 nM SB505124 prevented the overexpression of pSMAD2 and pSMAD5 by HUVEC exposed to disturbed flow for 24 h. SNAI1/2 expression due to exposure to disturbed flow was significantly reduced in the presence of SMAD2/3 inhibitor SB505124 (p < 0.05). SMAD5 inhibitor LDN193189 reduced the overexpression of pSMAD5 as well as pSMAD2. SNAI1/2 expression was significantly reduced in the presence of LDN193189 (p < 0.001) (scale bar 50 µM, magnification 40×). (B) Mean fluorescence intensity analysis of five random microscopic fields showed that there was a significant downregulation of SNAI1/2 in the presence of LDN193189 compared to SB505124 (p < 0.001). DF represents disturbed shear stress without any oscillatory flow. * represents p < 0.05, ** p < 0.01, and *** p < 0.001 vs. respective static or parallel uniform shear-treated groups.