title: The cytoplasm of living cells behaves as a poroelastic material.
abstract: The cytoplasm is the largest part of the cell by volume and hence its rheology sets the rate at which cellular shape changes can occur. Recent experimental evidence suggests that cytoplasmic rheology can be described by a poroelastic model, in which the cytoplasm is treated as a biphasic material consisting of a porous elastic solid meshwork (cytoskeleton, organelles, macromolecules) bathed in an interstitial fluid (cytosol). In this picture, the rate of cellular deformation is limited by the rate at which intracellular water can redistribute within the cytoplasm. However, direct supporting evidence for the model is lacking. Here we directly validate the poroelastic model to explain cellular rheology at short timescales using microindentation tests in conjunction with mechanical, chemical and genetic treatments. Our results show that water redistribution through the solid phase of the cytoplasm (cytoskeleton and macromolecular crowders) plays a fundamental role in setting cellular rheology at short timescales.
authors.affiliation: London Centre for Nanotechnology, University College London, London, UK.
authors.forename: Emad
authors.initials: E
authors.lastname: Moeendarbary
authors.forename: Léo
authors.initials: L
authors.lastname: Valon
authors.forename: Marco
authors.initials: M
authors.lastname: Fritzsche
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Harris
authors.forename: Dale A
authors.initials: DA
authors.lastname: Moulding
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Thrasher
authors.forename: Eleanor
authors.initials: E
authors.lastname: Stride
authors.forename: L
authors.initials: L
authors.lastname: Mahadevan
authors.forename: Guillaume T
authors.initials: GT
authors.lastname: Charras
mesh_terms: D001696:Biomechanical Phenomena; D048430:Cell Shape; D048429:Cell Size; D003593:Cytoplasm / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology; D004548:Elasticity; D008954:Models, Biological; D016062:Porosity; D012212:Rheology; D013314:Stress, Mechanical