Low shear stress induces vascular endothelial cells apoptosis via miR-330 /SOD2 /HSP70 signaling pathway

Abstract

Atherosclerosis (AS) is a chronic disease initiated by vascular endothelial dysfunction, with low shear stress (SS) being a critical inducing factor in this dysfunction. Apoptosis, a form of programmed cell death, is closely associated with AS progression. However, the impact of low SS on endothelial apoptosis and its specific molecular mechanisms remains unclear. Our study revealed that low SS induces apoptosis in endothelial cells and contributes to endothelial dysfunction. Under low SS conditions, miR-330 expression was markedly upregulated, which subsequently targeted and inhibited SOD2 expression, leading to ROS accumulation and oxidative stress. Overexpression of SOD2 under low SS conditions markedly elevated HSP70 expression, contributing to endothelial homeostasis. However, when HSP70 expression was inhibited in the context of SOD2 overexpression, there was a significant increase in pro-apoptotic proteins (BAX and cleaved-caspase-3) and total apoptosis rate, along with a significant reduction in endothelial function markers such as nitric oxide and endothelial nitric oxide synthase. Notably, our experiments indicated no direct interaction between SOD2 and HSP70. Furthermore, inhibiting ROS production significantly raised HSP70 expression, suggesting that SOD2 regulates HSP70 in an indirect process involving ROS. In summary, our findings elucidate that low SS induces endothelial apoptosis and dysfunction through the miR-330/SOD2/HSP70 signaling pathway, providing valuable insights into AS intervention and prevention.