Effects of mechanical stresses on the migrating behavior of endothelial cells

Objective: Endothelial cells are exposed to a variety of mechanical stresses, which modulate a number of endothelial functions. One of the important functions of endothelial cells is their migrating ability displayed at healing of vascular injury and angiogenesis. The present study aimed to elucidate the effects of mechanical stresses on the migrating behavior of bovine aorta endothelial cells (BAECs). Methods: BAECs were cultured on a fibronectin-coated elastic silicone membrane. A narrow scar (ca. 200 μ m in width) was made by a scratch in the confluent monolayer of BAECs, and migrating behavior of remaining cells into the vacant area was measured under controlled mechanical stresses onto the cells. Results: When the silicone membrane was continuously stretched by 20% at a stroke perpendicular to the scar, cell migration was strongly accelerated. In contrast, when a 20% prestretched silicone membrane in the same axis as above was relaxed, which effectively generated compressive force onto the cells, cell migration toward the vacant area was significantly inhibited. When mechanical stresses were applied parallel to the scar, cell migration was accelerated moderately by either stretch or compression. Direction of migration and lamellipodia formation was also affected significantly by mechanical stresses. Conclusion: Migrating behavior of BAECs is influenced not only by the modes (stretch or compression) of the applied mechanical stress but also by its orientation (perpendicular or parallel to the scar).