Figure 6.
Reduction of endothelial apoptosis and endothelial activation by sildenafil in vitro. Mouse cardiac endothelial cells (MCEC) were incubated with either phosphate buffered saline (PBS)/ 0,1% dimethylsulfoxide (DMSO) (control [ctr]), 100 nm etoposide (eto), an inducer of cell death, or with 100 nm etoposide and 34 nm sildenafil (eto+sil) for 24 hours before analysis. (A) MTT assay showed higher optical density of eto+sil group versus eto-only group. (B) Staining for apoptotic cell marker caspase 3 (Casp3) showed reduced Casp3+ cells per high-power field (HPF) in eto+sil group compared to eto-only group. (C) Flow cytometry analysis of CD86, a costimulatory and endothelial activation marker, showed reduced percentage of endothelial CD86high cells in eto+sil group compared to eto-only group. Signif icance was tested by Student’s t-test (*P<0.05; n=2-3 experiments with at least triplicates per condition). Error bars indicate mean ± standard error of the mean.