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The Mechanics of Poro-Elastic Contractile Actomyosin Networks As a Model System of the Cell Cytoskeleton
Published on: March 10, 2023
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Stress relaxation in epithelial monolayers is controlled by the actomyosin cortex
Nargess Khalilgharibi1,2, Jonathan Fouchard1, Nina Asadipour3
1London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK.
Nature Physics
|February 11, 2021
Summary
Epithelial monolayers dissipate mechanical stress through rapid actomyosin remodeling, behaving rheologically like single cells. This cellular biopolymer activity governs tissue-level stress relaxation and length changes.
Area of Science:
- Biophysics
- Cell Biology
- Tissue Engineering
Background:
- Epithelial monolayers form critical barriers in the body, requiring mechanical resilience.
- Understanding their response to rapid mechanical deformation is crucial for tissue function.
Purpose of the Study:
- To investigate the mechanical response and stress dissipation mechanisms of epithelial monolayers under stretch.
- To elucidate the role of cellular components in monolayer rheology.
Main Methods:
- Subjecting suspended epithelial monolayers to controlled stretching.
- Analyzing stress relaxation dynamics using power-law models with exponential cut-offs.
- Perturbing the actomyosin cytoskeleton to assess its role.
Main Results:
- Monolayers dissipate stress within seconds, with relaxation following a power law with an exponential cut-off.
- Stress relaxation involves increased monolayer length due to active biopolymer remodeling.
- Both large monolayers and single cells exhibit similar stress relaxation dynamics, governed by actomyosin activity.
Conclusions:
- Actomyosin dynamics are the primary drivers of epithelial monolayer rheology.
- Cell-cell junctions and intermediate filaments stabilize monolayers but do not actively relax stress.
- Epithelial monolayers can adapt their length and dissipate stress through molecular-scale remodeling.
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