Overexpression of angiopoietin-1 reduces doxorubicin-induced apoptosis in cardiomyocytes

摘要

Doxorubicin(Dox) is a major anticancer chemotherapeutic agent.However,it causes cardiomyopathy due to the side effect of cardiomyocyte apoptosis.We have previously reported that angiopoietin-1 significantly reduced myocardial infarction after ischemic injury and protected cardiomyocytes from oxidative stress-induced apoptosis.It is hypothesized that angiopoietin-1 may protect cardiomyocytes from Dox-induced apoptosis.Cardiomyocytes H9C2 were transfected with adenovirus expressing angiopoietin-1(Ad5-Ang-1) 24 h before the cells were challenged with Dox at a concentration of 2 μmol/L.Ad5-GFP served as the vector control.Cardiomyocyte apoptosis was evaluated using Annexin V-FITC staining and caspase-3 and caspase-8 activity was determined by Western blotting.The results showed that Dox treatment significantly induced cardiomyocyte apoptosis as evidenced by the greater number of Annexin V-FITC stained cells and increases in caspase-3 and caspase-8 activity.In contrast,overexpression of angiopoietin-1 significantly prevented Dox-induced cardiomyocyte apoptosis.To elucidate the mechanisms by which angiopoietin-1 protected cells from Dox-induced apoptosis,we analyzed both extrinsic and intrinsic apoptotic signaling pathways.We observed that angiopoietin-1 prevented Dox-induced activation of both extrinsic and intrinsic apoptotic signaling pathways.Specifically,angiopoietin-1 prevented DOX-induced increases in FasL and Bax levels and cleaved caspase-3 and caspase-8 levels in H9C2 cells.In addition,overexpression of angiopoietin-1 also activated the pro-survival phosphoinositide-3 kinase(PI3K)/Akt signaling pathway and decreased Dox-induced nuclear factor-kappaB(NF-κB) activation.Our data suggest that promoting the expression of angiopoietin-1 could be a potential approach for reducing Dox-induced cardiomyocyte cytoxicity.