Sakamoto Naoya, Ohashi Toshiro, Sato Masaaki
Department of Bioengineering and Robotics, Biomechanics Laboratory, Graduate School of Engineering, Tohoku University, Sendai, Japan.
Ann Biomed Eng. 2006 Mar;34(3):408-15. doi: 10.1007/s10439-005-9043-y. Epub 2006 Feb 16.
Migration of smooth muscle cells (SMCs) in hyperplasia is thought to have a correlation with blood flow conditions. In this study, the effect of shear stress applied to endothelial cells (ECs) on SMC migration was examined using a newly designed EC-SMC coculture model (CM), in which bovine SMCs and ECs were separated by a collagen layer and a membrane filter. After exposing the CM to shear stresses of 0.5, 1.0, or 1.5 Pa for 48 h, the number of SMCs migrating into the collagen layer was counted. Under static conditions, the migration of SMCs in the CM increased compared with SMCs cultured alone. Shear stress of 1.5 Pa significantly suppressed the SMC migration (p < 0.05) compared with the static CM. Media conditioned with the CM exposed to shear stress of 1.0 Pa (p < 0.05) and 1.5 Pa (p < 0.005) exhibited reduction in activated matrix metalloproteinase-2 (MMP-2) compared with the static CM, as analyzed by zymography. Addition of an inhibitor of nitric oxide (NO) synthase, N (omega)-nitro-L: -arginine methyl ester, to the media inhibited the effect of 1.5 Pa shear stress on SMC migration but MMP-2 activity was unaffected. These results suggest that physiological shear stress has protective roles in atherosclerogenesis.
平滑肌细胞（SMC）在增生过程中的迁移被认为与血流状况相关。在本研究中，使用新设计的内皮细胞（EC）-平滑肌细胞共培养模型（CM），检测施加于内皮细胞的剪切应力对平滑肌细胞迁移的影响，其中牛平滑肌细胞和内皮细胞被胶原层和膜滤器分隔。将共培养模型暴露于0.5、1.0或1.5 Pa的剪切应力下48小时后，计数迁移到胶原层中的平滑肌细胞数量。在静态条件下，与单独培养的平滑肌细胞相比，共培养模型中平滑肌细胞的迁移增加。与静态共培养模型相比，1.5 Pa的剪切应力显著抑制了平滑肌细胞的迁移（p < 0.05）。通过酶谱分析，与静态共培养模型相比，暴露于1.0 Pa（p < 0.05）和1.5 Pa（p < 0.005）剪切应力的共培养模型条件培养基中活化基质金属蛋白酶-2（MMP-2）减少。向培养基中添加一氧化氮（NO）合酶抑制剂N（ω）-硝基-L-精氨酸甲酯可抑制1.5 Pa剪切应力对平滑肌细胞迁移的影响，但MMP-2活性不受影响。这些结果表明，生理剪切应力在动脉粥样硬化发生过程中具有保护作用。
