Involvement of GEF-H1 in EC inflammatory activation induced by chronic 18% CS.

<p>Cells were transfected with GEF-H1-specific or non-specific siRNA, followed by 18% CS for 48 or 72 hours. (<b>A)</b> Effect of GEF-H1 knockdown on CS-induced ICAM1 expression was analyzed in static and stretched cells. Probing for β-actin served as a normalization control. SiRNA-induced protein knockdown was confirmed by western blot; n = 3, *P <0.05 vs. ns-RNA. Effect of GEF-H1 knockdown on CS-induced soluble ICAM1 <b>(B)</b> and IL-8 production <b>(C)</b> in the culture media was evaluated by ELISA assay; n = 4, *P<0.05 vs. 5% CS. (<b>D)</b> Effect of ectopic expression of wild type (GEF-H1-WT) and dominant negative mutant of GEF-H1 (GEF-H1-DN) on CS-induced ICAM1 expression (48 hrs was compared to non-transfected (nonTF) control cells. Probing for β-actin served as a normalization control. Expression of endogenous and recombinant GEF-H1 variants was confirmed by western blot; n = 3, *P <0.05. (<b>E)</b> Effect of microtubule stabilization by treatment with taxol (0.5 μM) on CS-induced ICAM1 expression (48 hrs). Probing for β-actin served as a normalization control. Expression of endogenous and recombinant GEF-H1 variants was confirmed by western blot; n = 3, *P <0.05.