Membrane Loads in a Compressed Skeletal Muscle Cell Computed Using a Cell-Specific Finite Element Model

Abstract

Deep tissue injury (DTI) is a serious lesion typically involving necrosis of skeletal muscle tissue under intact skin. Currently, considerable research efforts are invested in understanding the mechanisms underlying the onset and progression of DTI. Recent studies indicated the involvement of deformation-related events at the cellular scale. Nevertheless, the specific processes at the cell level which ultimately lead to DTI formation are still unknown. We hypothesize that stretchinduced increase in the local permeability of plasma membranes may lead to intracellular cytotoxic concentrations of cell metabolites. A three-dimensional finite-element (FE) analysis of a compressed single skeletal muscle cell (from a murine C2C12 myoblast cell line) was conducted in order to study the aspects of localized plasma membrane stretches. Geometry of the cell was based on confocal microscopy images of an actin-stained cell, specifically stained with FITC-labeled phalloidin. The cell was compressed in the FE simulation by a rigid plate, up to a maximal global deformation of 70%. Large deformation strain analysis was preformed, and maximal local principal strains in the plasma membrane were obtained as function of the global deformation applied to the cell. It was found that platen compression causes substantial tensional strains in segments of the plasma membrane.