BACKGROUND: Atherosclerosis is characterized by the accumulation of fatty and fibrotic plaques, which preferentially develop at curvatures and branches along the arterial trees that are exposed to disturbed flow. However, the mechanisms by which endothelial cells sense disturbed flow are still unclear. METHODS: The partial carotid ligation mouse model was used to investigate disturbed flow-induced atherogenesis. In vitro experiments were performed using the ibidi system to generate oscillatory shear stress and laminar shear stress. RESULTS: The data showed that human endothelial cells express a high level of 5-HT CONCLUSIONS: Taken together, these results uncover that endothelial 5-HT