Simultaneous Measurement of Morphology and Traction Forces of Endothelial Cells Under Fluid Shear Stress

Under fluid shear stress, vascular endothelial cells (ECs) cultured in a monolayer are known to exhibit marked elongation and orientation to the direction of flow [1]. It is also observed that intracellular F-actin filament distributions changed depending on the amplitude of shear stress and the direction of flow, suggesting morphology of ECs is closely related to cytoskeltal structure [2]. ECs generate contractile forces by the actin-myosin machinery and the forces are transmitted to underlying substrate as cellular traction forces. We hypothesize that reorganization of cytoskeletal structures regulates traction forces in ECs exposed to fluid shear stress. In order to measure traction forces and cell morphology simultaneously, we have developed a newly designed flow-imposed device in which a substrate with arrays of elastomeric micropillars (3 μm in diameter and 10 μm in height) is integrated on the bottom of a parallel plate flow chamber. In this study, traction force distributions and morphological changes in GFP-tagged ECs in a monolayer under fluid flow are simultaneously evaluated through image analysis in a spatial and a temporal manner.