Shear stress distribution on the surface of endothelial cells during flow-induced morphological remodeling

Morphological remodeling of endothelial cells that was induced by blood flow is considered an adaptive response to a mechanical stimulus. To determine the mechanisms of the response, we examined how shear stress on the surface of the same group of cells changed. The surface geometry of the cells was measured by confocal laser scanning microscopy, and the shear stress distribution on the measured cell surface was determined using the flow field simulated by computational fluid dynamics. When the cells, which were polygonal without alignment at the beginning of the flow exposure, elongated and aligned in the flow direction, the mean shear stress of the cells decreased with time. However, there were some cells whose mean shear stress was increased, and the morphological change of each cell was not always adaptive. The results show the importance of interaction with surrounding cells to the adaptive response as demonstrated in the endothelial layer.