Effect of fluid shear stress on smooth muscle cell migration and permeability of endothelial monolayer in endothelial-smooth muscle cells cocultured model

In this study, the effect of fluid shear stress on migration of smooth muscle cells (SMCs) and permeability of endothelial cells (ECs) were investigated using a newly designed EC-SMC cocultured model (CM). The CM was composed of bovine aortic ECs and SMCs, a collagen layer, and a porous membrane. After exposing to shear stress for 48 hours, the number of SMCs migrating into the collagen layer was counted. Permeability of ECs to bovine serum albumin was also measured after exposure to shear stress. Under static conditions, the migration of SMCs in the CM increased compared to SMCs cultured alone. Shear stress of 1.5Pa significantly suppressed the SMC migration (p < 0.05) compared to the static CM. Media conditioned with the CM exposed to shear stress of 1.5 Pa exhibited reduction in activated matrix metal loproteinase-2 compared to the static CM, as analyzed by zymography. After exposure to shear stress, EC permeability in the CM significantly decreased compared to the static CM (p < 0.05), whereas EC permeability of EC cultured alone did not change compared to the statically cultured EC. These results suggest that the cellular interactions between ECs and SMC have important influence on SMC migration and EC permeability, and shear stress may have protective roles in atherosclerosis.