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Up-regulation of integrin beta 3 expression by cyclic stretch in human umbilical endothelial cells.

The effect of uni-axial cyclic mechanical stretch on the expression of the adhesion protein integrin was investigated. Human umbilical endothelial cells (HUVECs) cultured on fibronectin coated silicon membranes were subjected to uni-axial cyclic stretch. The level of expression of integrin beta 3 mRNA was found to be increased and peaked at 4 hours in response to cyclic stretch using a semiquantitative RT-PCR method. The increased level of the integrin mRNA from stretched HUVECs remained higher than that from non-stretched controls. The amount of integrin beta 3 also increased and peaked at 12 hr. Immuno-fluorescent microscopy revealed that the amount of integrin beta 3 adhesions increased in stretched HUVECs compared with that in non-stretched HUVECs. These results suggest that uni-axial cyclic stretch up-regulates the expression of integrin beta 3. This increase in integrin beta 3 may enhance the adhesiveness to the substratum and contribute to the protection of HUVECs against being peeled off from the vessel wall.