Anisotropic, Three-Dimensional Deformation of Single Attached Cells Under Compression

Abstract

Abstract-Quantifying three-dimensional deformation of cells under mechanical load is relevant when studying cell deformation in relation to cellular functioning. Because most cells are anchorage dependent for normal functioning, it is desired to study cells in their attached configuration. This study reports new threedimensional morphometric measurements of cell deformation during stepwise compression experiments with a recently developed cell loading device. The device allows global, unconfined compression of individual, attached cells under optimal environmental conditions. Three-dimensional images of fluorescently stained myoblasts were recorded with confocal microscopy and analyzed with image restoration and three-dimensional image reconstruction software to quantify cell deformation. In response to compression, cell width, cross-sectional area, and surface area increased significantly with applied strain, whereas cell volume remained constant. Interestingly, the cell and the nucleus deformed perpendicular to the direction of actin filaments present along the long axis of the cell. This strongly suggests that this anisotropic deformation can be attributed to the preferred orientation of actin filaments. A shape factor was introduced to quantify the global shape of attached cells. The increase of this factor during compression reflected the anisotropic deformation of the cell.

Numerical investigation of the active role of the actin cytoskeleton in the compression resistance of cells

“…The increased resistance of spread cells to compression results from the stretching of dominant contractile SF bundles. This mechanism is supported by the experimental observations of Peeters et al (2004) for polarised cell geometries, where it is reported that long actin fibres restrict deformation of the cell and nucleus in the direction perpendicular to the dominant fibre orientation. This observation underlines the fully predictive nature of our modelling framework which provides an insightful link between cell geometry, SF distribution and response to mechanical stimuli.…”

Multiscale cartilage biomechanics: technical challenges in realizing a high-throughput modelling and simulation workflow

“…This metric, obtained from biphasic analysis, can be an indicator of cell-to-cell signalling. More common cellular deformation metrics are calculated by first finding the mass moment inertia of each cell and then finding the eigenvalues of this tensor, which represent the principal moments of inertia [57]. These eigenvalues are processed to calculate axis lengths of the inertial ellipsoid, which in turn provide a shape factor from their ratio [51].…”

Distribution of Internal Strains Around Bony Prominences in Pigs

“…Nonetheless, evidence for this class of pressure ulcers in animal models dates back to the early 1980s. 7,12,13,34,50,53,55 During prolonged tissue loading two different mechanisms of tissue damage have been identified. One mechanism is vascular, in which tissue compression occludes blood vessels in the affected region causing ischemia.…”