NAMPT regulates senescence, proliferation, and migration of endothelial progenitor cells through the SIRT1 AS lncRNA/miR-22/SIRT1 pathway

The importance of endothelial progenitor cells (EPCs) in cardiovascular diseases has been demonstrated by numerous studies. Previous studies have shown that Nicotinamide phosphoribosyltransferase (NAMPT) plays a role in EPC development by regulating Sirtuin 1 (SIRT1), but the specific mechanism has not yet been elucidated. After stimulating EPCs with NAMPT, expression of SIRT1 and SIRT1 antisense long non-coding RNA (AS lncRNA) was upregulated. Upon transfection of an SIRT1 AS lncRNA overexpression vector into EPCs, SIRT1 expression was upregulated. Upon transfection of a small interfering RNA (siRNA) that targets SIRT1 AS lncRNA along with NAMPT, SIRT1 AS lncRNA was downregulated and NAMPT-induced SIRT1 expression was reduced. We used software analyses and a dual-luciferase reporter assay to demonstrate that microRNA (miR)-22 regulated SIRT1 and SIRT1 AS lncRNA. Our data suggest that SIRT1 AS lncRNA relieves miR-22-induced SIRT1 downregulation by competitively sponging miR-22. By measuring EPC senescence, proliferation, and migration, we found that NAMPT inhibited EPC senescence through an SIRT1 AS lncRNA/miR-22/SIRT1 pathway and promoted EPC proliferation and migration. These findings provide a new theoretical basis for the prevention and treatment of atherosclerosis (AS) and other cardiovascular diseases.