Affiliations: Department of Polymer Chemistry and Biomaterials, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands | Department of Physics of Complex Fluids, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands | Department of BIOS/Lab-on-a-Chip, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
Note: [] Both authors contributed equally.
Note: [] Address for correspondence: Dr. André A. Poot, University of Twente, Zuidhorst, Room ZH124, P.O. Box 217, 7500 AE Enschede, The Netherlands. Tel.: +31 53 489 3671; Fax: +31 53 489 2155; E-mail: [email protected].
Abstract: Vascular endothelial cells form the inner lining of all blood vessels and play a central role in vessel physiology and disease. Endothelial cells are highly responsive to the mechanical stimulus of fluid shear stress that is exerted by blood flowing over their surface. In this study, the immediate micromechanical response of endothelial cells to physiological shear stress was characterized by tracking of ballistically injected, sub-micron, fluorescent particles. It was found that the mean squared displacement (MSD) of the particles decreases by a factor 1.5 within 10 min after the onset of shear stress. This decrease in particle motion is transient, since the MSD returns to control values within 15–30 min after the onset of shear. The immediate micromechanical stiffening is dependent on activation of the vascular endothelial growth factor receptor (VEGFR)-2, because inhibition of the receptor abrogates the micromechanical response. This work shows that the cytoskeleton is actively involved in the acute, functional response of endothelial cells to shear stress.
