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

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/cm(2)) 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/cm(2)) 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/cm(2) had less effect on the secretion of MCP-1 compared with 4 dyn/cm(2). This research provides data for understanding the mechanism of the contribution of hemodynamic forces to atherosclerosis.