Resveratrol attenuates cigarette smoke induced endothelial apoptosis by activating Notch1 signaling mediated autophagy

Abstract

Background: Increasing evidences have showed that endothelial apoptosis contributes to cigarette smoke (CS)-induced disease progression, such as chronic obstructive pulmonary disease (COPD). Our previous studies have validated Notch1 as an anti-apoptotic signaling in cigarette smoke (CS)-induced endothelial apoptosis. Resveratrol (RESV) is a naturally occurring polyphenol that exhibits an anti-apoptotic activity in endothelial cells that exposed to many kinds of destructive stimulus. However, the effects of resveratrol on Notch1 signaling in CS-induced endothelial apoptosis have not yet been fully elucidated. Therefore, the aim of this study was to examine whether RESV can protect endothelial cells from cigarette smoke induced apoptosis via regulating Notch1 signaling. Methods: Human umbilical vein endothelial cells (HUVECs) were pretreated with RESV for 2 h, followed by cotreatment with 2.5%CSE for 24h to explore the role of RESV in CSE induced endothelial apoptosis. 3-methyladenine (3-MA) or rapamycin was used to alter autophagic levels. Lentivirus Notch1 intracellular domain (LV-N1ICD) or γ-secretase inhibitor (DAPT) were used to change Notch1 expression. The expression of Notch1, autophagic and apoptotic markers were examined by Western blot and the apoptosis rate was detected by Flow cytometry analysis. Results: Our results showed that activating autophagy reduced CSE-induced endothelial apoptosis, while blocking autophagy promoted cell apoptosis in HUVECs. RESV pretreatment attenuated the CSE-induced endothelial apoptosis and activated Notch1 signaling. RESV pretreatment also increased LC3b-II and Beclin1 production, decreased p62 and mTOR expression. 3-MA treatment inhibited autophagy and aggravated CSE induced apoptosis, while rapamycin promoted autophagy, led to a decrease in cell apoptosis. LV-N1ICD transfection upregulated autophagy and reduced apoptosis. However, this protective effect was abolished by 3-MA treatment. In cells treated with DAPT, autophagy was decreased, while apoptosis was increased. RESV partly rescued the DAPT induced apoptosis by activating Notch1 signaling. Conclusion: In HUVECs, RESV attenuates CSE induced endothelial apoptosis by inducing autophagy in a Notch1-dependent manner.