Fluid shear stress induces the secretion of monocyte chemoattractant protein‐1 in cultured human umbilical vein endothelial cells

Abstract

In this study we investigated the patterns of fluid shear stress on induction of monocyte chemoattractant protein‐1 (MCP‐1) secretion in cultured human umbilical vein endothelial cells (HUVECs). MCP‐1 is a potent special chemoattractant, which recruits monocytes into the sub‐endothelium. This process is one of the early events of atherosclerosis. We examined the pattern of fluid shear stress inducing the secretion of MCP‐1 in cultured HUVECs from the view of biomechanics. In our experiments, HUVECs were subjected to controlled levels of shear stress (4, 10, 20 dyn/cm²) in a parallel plate flow chamber. MCP‐1 in HUVECs of different periods was measured by an immunohistochemistry method and digital image analysis; MCP‐1 in perfusion was measured by sandwich ELISA. The results demonstrated the increase of MCP‐1 synthesis and secretion by shear stress was time‐ and force‐dependent. The accumulated level of MCP‐1 in HUVECs under lower shear stress (4 dyn/cm²) for 4–5 hrs was 3‐fold compared with that for static cells. When the shear stress lasted to 6 hrs, the secretion of MCP‐1 was reduced to normal levels and could not be increased even when the shear stress lasted for 12 hours. 10 dyn/cm² had less effect on the secretion of MCP‐1 compared with 4 dyn/cm². This research provides data for understanding the mechanism of the contribution of hemodynamic forces to atherosclerosis.