MicroRNA-216a induces endothelial senescence and inflammation via Smad3/IκBα pathway

Vascular endothelial senescence contributes to atherosclerosis and coronary artery disease (CAD), but the mechanisms are yet to be clarified. We identified that microRNA-216a (miR-216a) significantly increased in senescent endothelial cells. The replicative senescence model of human umbilical vein endothelial cells (HUVECs) was established to explore the role of miR-216a in endothelial ageing and dysfunction. Luciferase assay indicated that Smad3 was a direct target of miR-216a. Stable expression of miR-216a induced a premature senescence-like phenotype in HUVECs with an impairment in proliferation and migration and led to an increased adhesion to monocytes by inhibiting Smad3 expression and thereafter modulating the degradation of NF-κB inhibitor alpha (IκBα) and activation of adhesion molecules. Conversely, inhibition of endogenous miR-216a in senescent HUVECs rescued Smad3 and IκBα expression and inhibited monocytes attachment. Plasma miR-216a was significantly higher in old CAD patients (>50 years) and associated with increased 31% risk for CAD (odds ratio 1.31, 95% confidence interval 1.03-1.66; P = .03) compared with the matched healthy controls (>50 years). Taken together, our data suggested that miR-216a promotes endothelial senescence and inflammation as an endogenous inhibitor of Smad3/IκBα pathway, which might serve as a novel target for ageing-related atherosclerotic diseases.