Silent information regulator 1 (SIRT1) promotes the migration and proliferation of endothelial progenitor cells through the PI3K/Akt/eNOS signaling pathway

Silent information regulator 1 (SIRT1) mediates many effects of caloric restriction (CR) on an organism’s lifespan and metabolic pathways. Recent reports have also emphasized its role in vascular function. The present study was designed to investigate the effects of SIRT1 on the properties of mouse spleen derived endothelial progenitor cells (EPCs). SIRT1 in EPCs was significantly increased by serum and by vascular endothelial growth factor (VEGF). Moreover, an adenovirus (Ad) vector expressing SIRT1 (Ad-SIRT1)-mediated overexpression of SIRT1 directly enhanced migration and proliferation of EPCs, whereas silencing of endogenous SIRT1 in EPCs inhibited cell functions. In addition, LY294002 (a PI3K inhibitor), sc-221226 (an Akt inhibitor), and L-NAME (an NOS inhibitor) abolished Ad-SIRT1-induced migration and proliferation of EPCs, and prevented nitric oxide (NO) production. Phosphorylation of Akt, PI3K, and endothelial nitricoxide synthase (eNOS) were up-regulated by Ad-SIRT1, which was attenuated by LY294002, sc-221226, and L-NAME. Together, the results suggested that through the PI3K/Akt/eNOS signaling pathway, SIRT1 plays an important role in the biological properties of EPCs.