Simvastatin promotes cardiac microvascular endothelial cells proliferation, migration and survival by phosphorylation of p70 S6K and FoxO3a.

Restenosis severely limits the overall efficacy of interventions. One of the reasons is the lack of reendothelialization related to inhibition of endothelial cell proliferation and migration since drug is delivered to the luminal surface. Statins can promote angiogenic processes by improving endothelial function, proliferation and migration in cardiac microvascular endothelial cells (CMECs). This study clarified the effect of simvastatin on Akt/mTOR/p70 S6K and FoxO3a signalling pathways in rat CMECs following pretreated with rapamycin. Rapamycin treatment for 24 h inhibited CMECs' proliferation, migration and NO (nitric oxide) secretion, but with increased cell apoptosis and reactive oxygen species (ROS) production. In contrast, simvastatin pretreatment significantly improved proliferation, migration and NO secretion, and inhibited CMECs' apoptosis and ROS production in rapamycin-induced CMECs. Western blot assay showed that, after treatment with simvastatin, the phosphorylation of Akt/mTOR/p70 S6K and FoxO3a were up-regulated in rapamycin-induced CMECs, which was significantly reversed by pretreatment with LY294002. The data suggest that simvastatin inhibits rapamycin-induced CMECs dysfunction and apoptosis, probably through activation of PI3K/Akt/mTOR/p70 S6K and mTOR/FoxO3a signalling pathway in a sequential manner and this pathway may be important in some of the pleiotropic effects of statins.