2219-PUB: Antioxidant Protective Effect and Mechanism of Selenoprotein S in Diabetic Vascular Endothelium-Mimicking Microenvironment

Abstract

Endothelial dysfunction is an initiating key step for diabetic macrovascular complications, and it is closely related to the hemodynamic microenvironment in vivo. However, diabetic patients usually coexist with other cardiovascular risk factors, and the more powerful targeting strategy for protecting endothelium is still limited. Selenoprotein S (SelS) was found in our previous study that could increase vascular endothelial cells resistance to oxidative stress associated with protein kinase C α (PKCα). Thus, in this study, we constructed a diabetic vascular endothelial bionic microenvironment mimicking hyperglycemia and/or hyperlipidemia based on microfludic chip through modulating the concentration of medium glucose and oxidized low density lipoproteins. Our results showed that under diabetic vascular endothelial bionic microenvironment, the upregulation of SelS enhanced nitric oxide synthase (eNOS) expression and reduced endothelin-1 level in human aortic endothelial cells (HAECs), accompany with increase in cell viability and SOD1 and SOD2 activity, and decrease in ROS. Furthermore, SelS overexpression attenuated the activation of PKCα, which subsequently promoted the activation of PI3K/Akt/eNOS pathway. Conversely, the knockdown of SelS resulted in an enhancement of endothelial injury. These findings suggest that SelS could protect endothelial cells from oxidative stress injury under diabetic vascular endothelial bionic microenvironment through PKCα and PI3K/Akt/eNOS pathway. Our results offer a promising and biomimetic platform for investigation on endothelial protection, and provide evidence of SelS as potential novel target to treat diabetic macrovascular complications. Disclosure S. Yu: None. Y. Zhong: None. L. Men: None. J. Yao: None. J. Du: None. Funding National Natural Science Foundation of China (81570727)