title: Effects of oxidative stress-induced changes in the actin cytoskeletal structure on myoblast damage under compressive stress: confocal-based cell-specific finite element analysis.
abstract: Muscle cells are frequently subjected to both mechanical and oxidative stresses in various physiological and pathological situations. To explore the mechanical mechanism of muscle cell damage under loading and oxidative stresses, we experimentally studied the effects of extrinsic hydrogen peroxides on the actin cytoskeletal structure in C2C12 myoblasts and presented a finite element (FE) analysis of how such changes in the actin cytoskeletal structure affected a myoblast's capability to resist damage under compression. A confocal-based cell-specific FE model was built to parametrically study the effects of stress fiber density, fiber cross-sectional area, fiber tensile prestrain, as well as the elastic moduli of the stress fibers, actin cortex, nucleus and cytoplasm. The results showed that a decrease in the elastic moduli of both the stress fibers and actin cortex could increase the average tensile strain on the actin cortex-membrane structure and reduce the apparent cell elastic modulus. Assuming the cell would die when a certain percentage of membrane elements were strained beyond a threshold, a lower elastic modulus of actin cytoskeleton would compromise the compressive resistance of a myoblast and lead to cell death more readily. This model was used with a Weibull distribution function to successfully describe the extent of myoblasts damaged in a monolayer under compression.
authors.affiliation: Division of Biomedical Engineering, The Chinese University of Hong Kong, Rm. 429, Ho Sin Hang Engineering Building, Shatin, N.T. Hong Kong SAR, China.|Department of Mechanical Engineering, INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, UK.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Mechanical Engineering, INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, UK.
authors.forename: Damien
authors.initials: D
authors.lastname: Lacroix
authors.affiliation: Division of Biomedical Engineering, The Chinese University of Hong Kong, Rm. 429, Ho Sin Hang Engineering Building, Shatin, N.T. Hong Kong SAR, China. arthurmak@cuhk.edu.hk.
authors.forename: Arthur F T
authors.initials: AF
authors.lastname: Mak
mesh_terms: D008841:Actin Cytoskeleton / Q000737:chemistry*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D019245:Compressive Strength; D003198:Computer Simulation; D055119:Elastic Modulus; D020342:Finite Element Analysis; D051379:Mice; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal / Q000379:methods*; D032446:Myoblasts / Q000378:metabolism / Q000473:pathology*; D018384:Oxidative Stress; D022502:Stress Fibers; D013314:Stress, Mechanical; D013718:Tensile Strength
keywords: Actin cytoskeleton; Finite element modeling; Myoblast; Oxidative stress; Weibull distribution