The Poisson Ratio of the Cellular Actin Cortex Is Frequency Dependent

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

Abstract

Cell shape changes are vital for many physiological processes such as cell proliferation, cell migration, and morphogenesis. They emerge from an orchestrated interplay of active cellular force generation and passive cellular force response, both crucially influenced by the actin cytoskeleton. To model cellular force response and deformation, cell mechanical models commonly describe the actin cytoskeleton as a contractile isotropic incompressible material. However, in particular at slow frequencies, there is no compelling reason to assume incompressibility because the water content of the cytoskeleton may change. Here, we challenge the assumption of incompressibility by comparing computer simulations of an isotropic actin cortex with tunable Poisson ratio to measured cellular force response. Comparing simulation results and experimental data, we determine the Poisson ratio of the cortex in a frequency-dependent manner. We find that the Poisson ratio of the cortex decreases in the measured frequency regime analogous to trends reported for the Poisson ratio of glassy materials. Our results therefore indicate that actin cortex compression or dilation is possible in response to acting forces at sufficiently fast timescales. This finding has important implications for the parameterization in active gel theories that describe actin cytoskeletal dynamics.

Details

Original languageEnglish
Pages (from-to)1968-1976
Number of pages9
JournalBiophysical journal
Volume118
Issue number8
Publication statusPublished - 21 Apr 2020
Peer-reviewedYes

External IDs

PubMedCentral PMC7175418
Scopus 85082122253
ORCID /0000-0002-2433-916X/work/142250429

Keywords

Research priority areas of TU Dresden

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Subject groups, research areas, subject areas according to Destatis

Keywords

  • Actin Cytoskeleton, Actins, Cytoskeleton, Microscopy, Atomic Force, Models, Biological

Library keywords