1964-1972 Resveratrol ameliorates low shear stress-induced oxidative stress by suppressing ERK/eNOS-Thr495 in endothelial cells

Abstract

Fluid shear stress has been revealed to differentially regulate endothelial nitric oxide synthase (eNOS) distribution in vessels. eNOS, a key enzyme in controlling nitric oxide (NO) release, has a crucial role in mediating oxidative stress, and resveratrol (RSV)-mediated eNOS also attenuates oxidative damage and suppresses endothelial dysfunction. To observe the protective effect of RSV on low shear stress (LSS)-induced oxidative damage and the potential mechanisms involved, a parallel-plate flow chamber, which imposed a low level of stress of 2 dynes/cm2 to cells, was employed. Reactive oxygen species (ROS), NO and apoptotic cells were examined in LSS-treated endothelial cells (ECs) with or without RSV. Western blot analysis was used to examine LSS-regulated eNOS-Ser1177, Thr495 and Ser633, which were tightly associated with NO release. To further determine the underlying signaling pathways involved, extracellular signal-regulated kinase (ERK), a possible upstream target of eNOS-Thr495, was investigated, followed by examination of eNOS-Thr495 in ERK-inhibited cells. Additionally, eNOS mRNA expression levels were analyzed in cells challenged with LSS. The results revealed that RSV markedly decreased LSS-induced oxidative damage in ECs. Furthermore, eNOS-Ser1177 and Thr495 as well as phospho-ERK were time-dependently activated by LSS. The ERK inhibitor deactivated eNOS-Thr495, which was accompanied by increased intracellular superoxide dismutase (SOD) levels. Of note, the activation effect of LSS on ERK/eNOS was markedly eliminated by RSV. In conclusion, RSV exerts antioxidant effects by suppressing LSS-activated ERK/eNOS and may provide a potential therapeutic target for atherosclerosis.