Abstract: Objective To investigate the effect of low shear stress (LSS) on apoptosis of human vascular endothelial cells (ECs)
and explore the possible mechanisms. Methods Parallel flow chamber was used to apply LSS at 2 dyne/cm2 on EA.hy926 cells
derived from human umbilical vein endothelial cells for 120 min. Cell apoptosis following LSS was verified by morphological
observation, DAPI staining and TUNEL test. The level of intracellular reactive oxygen species (ROS) was measured by
dihydroethidium (DHE) and mitoSOX. Western blotting was performed to detect the activity of Akt in the cells. Results EC
detachment and apoptosis were observed after exposure to 2 dyne/cm2 LSS for 120 min. Time course study showed that the
phosphorylation level of Akt on residues Ser473 and Thr308 was elevated after flow initiation. Exposure to LSS at 2 dyne/cm2
for 120 min resulted in increased ROS production in the ECs at both the mitochondrial and cytoplasmic levels. Conclusion Akt
activation and increased ROS levels are involved in LSS-induced EC apoptosis.