2003 年 17 巻 1 号 p. 24-28
Actin filament dynamics in endothelial cells was observed during exposure to fluid shear stress. A plasmid encoding enhanced green fluorescent protein (GFP) fused to the amino terminus of actin was transfected into cultured bovine aortic endothelial cells (BAECs) using a liposomal method. This functional GFP-actin construct enabled observation of actin filaments in BAECs. BAECs were exposed to fluid shear stress of 2 Pa using a parallel plate flow chamber and dynamic behavior of actin filaments in BAECs expressing stable GFP-actin was observed under a time lapse fluorescence microscopy. Cytoskeletal reorganization during exposure to shear stress preceded changes in cell shape. In a typical example, dense peripheral bands located upstream side in a cell moved toward the nucleus and fine network structure of actin filaments was partly destroyed within 60 min. After 180 min, actin filaments started to form thick bundles in the whole region of the cell, followed by cell elongation to the flow direction. Changes in cell shape and cytoskeletal structure seemed to be finished around 300 min. The GFP-actin expressed in endothelial cells should reveal detailed moving process of actin filaments in endothelial cells under mechanical stimuli.