Spatial Distribution of Cytoskeletal Mechanical Properties in Vascular Smooth Muscle Cells

Abstract

The mechanical properties on a whole basis of cell are extensively studied whereas regional mechanical properties of the cytoskeleton (CSK) have not been characterized. To fill this gap, here we provide detailed intracellular maps of regional CSK stiffness and traction forces, as well as the structural rearrangement in vascular smooth muscle cells (VSMCs). We used micropatterning to restrict VSMC to a single island. Regional cell stiffness was measured with optical magnetic twisting cytometry and traction force microscopy was used to measure regional traction forces. Finally, we used F-actin staining to measure the regional F-actin distribution. From traction and cell height data we computed the prestress within a cell using finite element methods. Compared with the cell center, cell edges were systematically stiffer, more fluid-like and supported higher traction forces, and at the same time had slower remodeling dynamics. These findings provide the most detailed characterization to date concerning regional mechanical properties of the intact cytoskeleton.