Silencing profilin-1 confers protection from oxLDL injury in human vascular endothelial cells

Oxidized low density lipoprotein (oxLDL) plays a key role in the dysfunction, injury and apoptosis of vascular endothelial cells (ECs). Profilin-1, an actin-binding protein, is up-regulated during these processes of endothelial cells. The aim for this study is to investigate expression of profilin-1 in human vascular endothelial cells (HUVECs) in present of oxLDL and the protection effect by Silencing profilin-1 on HUVECs exposed to oxLDL and its mechanism. HUVECs were cultured and exposed to oxLDL (50 µg/ml) for 24 h and subsequently were treated with siRNA to inhibit gene profilin-1. Expression of protein and mRNA for profilin-1 and genes (caspase-3, Bax, Bcl-2, NF-κB and survivin) associated with apoptosis were determined using real-time PCR and western blot analysis, respectively. The cells injuries and apoptosis were examined by flow cytometry analysis. After exposed to oxLDL, the mRNA and protein levels of profilin-1 in HUVECs were significantly increased. Suppressed profilin-1 expression in oxLDL treated HUVECs by RNA-interference resulted in significant reduction and elevation of the mRNA and protein of caspase-3 and Bax, Bcl-2 and NF-κB and survivin, respectively. In addition, this is the first time that reports survivin involving oxLDL induced ECs injuries. Flow cytometry analysis showed the apoptosis ratio of oxLDL treated HUVECs significantly decreased after silencing profilin-1. These findings suggest that profilin-1 may play a key role in process of ECs injuries and apoptosis caused by oxLDL, and mechanism of its action involves various apoptosis related genes and deserves more attention.