Propagating stress waves during epithelial expansion

TL;DR

This paper introduces a coupled mechanical and cellular activity model for epithelial expansion, capturing stress wave propagation, viscoelasticity, and oscillatory behaviors observed in tissue morphogenesis.

Contribution

It presents a novel model linking strain, polarization, and contractility, explaining stress wave propagation and oscillations during epithelial tissue expansion.

Findings

Reproduces experimental stress build-up in cell monolayers

Predicts traveling mechanical waves during tissue expansion

Demonstrates viscoelastic behavior in epithelial tissues

Abstract

Coordinated motion of cell monolayers during epithelial wound healing and tissue morphogenesis involves mechanical stress generation. Here we propose a model for the dynamics of epithelial expansion that couples mechanical deformations in the tissue to contractile activity and polarization in the cells. A new ingredient of our model is a feedback between local strain, polarization and contractility that naturally yields a mechanism for viscoelasticity and effective inertia in the cell monolayer. Using a combination of analytical and numerical techniques, we demonstrate that our model quantitatively reproduces many experimental findings [Nat. Phys. 8, 628 (2012)], including the build-up of intercellular stresses, and the existence of traveling mechanical waves guiding the oscillatory monolayer expansion.