Abstract:Objective To investigate the influence of HSP27 on the cardiovascular protection of estrogen by gene silencing technique. Methods HSP27 siRNA was transfected to human umbilical vein endothelial cells (HUVECs). The transfection efficiency was assessed by immunofluorescence technique. The expressions of HSP27 mRNA and protein in HUVECs were determined by RT-PCR and Western blot, respectively. HUVECs transfected with HSP27 siRNA were incubated with 1×10-7 mol/L estradiol (E2) for 24 hours. The level of nitric oxide (NO) in medium was determined by nitrite/nitrate colorimetric method, and the levels of intercellular adhesion molecule-1 (ICAM-1) and endothelin-1 (ET-1) in the supernatant were determined by ELISA. Results HSP27 siRNA sequence significantly reduced the expression of HSP27 in protein and mRNA levels. E2 at the level of 1×10-7 mol/L could obviously promote the secretion of NO from HUVECs, and decrease the ICAM-1 and ET-1 levels. After transfection with HSP27 siRNA, E2-mediated secretion of NO and ICAM-1 by HUVECs was inhibited. However, the level of ET-1 had no significant change. Conclusions HSP27 may influence the role of E2 on the secretion of NO and ICAM-1 in HUVECs, and protect the cardiovascular system.