A NOVEL TECHNIQUE FOR THE CHARACTERIZATION OF ENDOTHELIAL CELL MECHANICS
Abstract
Circumferential distension of the arterial wall during the cardiac cycle regulates endothelial cell (EC) morphology and function. We have previously shown that cyclic stretching of ECs leads to activation of signaling events relevant to atherosclerosis, but that this signaling subsides when the cells align perpendicular to stretch. We hypothesized that the purpose of this cellular response is to maintain a homeostatic stress level within the cell. Stresses within the cell are both born and created by cytoskeletal components. Stress fibers create tension that is transmitted to substratum via integrin connections. To test if this alignment response affects the forces applied to the substratum by stretching the ECs, we are developing a system to quantify substrate deformation caused by stretching ECs. The technique uses a poly(ethylene glycol) diacrylate hydrogel having an elastic modulus appropriate for traction microscopy and embedded with fluorescent beads. The traction microscopy system was comprised of computer controlled actuators and a clamping mechanism used to stretch the fluorescent bead embedded hydrogels under a confocal microscope objective. Image analysis via cross-correlation of bead displacements was used to generate the displacement field of the hydrogel immediately below and surrounding the cell. The preliminary results obtained indicate a successful proof of concept and show the method to be sound in principle. The system provides for the development of unique experimental conditions including the ability to perform uniaxial and biaxial stretching. In conclusion, the development of a novel method for the characterization of endothelial cell mechanics appears to be possible. However, the technique must be further developed and refined in order to increase efficacy and repeatability.
Citation
Mohedas, Agustin (2007). A NOVEL TECHNIQUE FOR THE CHARACTERIZATION OF ENDOTHELIAL CELL MECHANICS. Available electronically from https : / /hdl .handle .net /1969 .1 /5703.