Hydrodynamics of stratified epithelium: steady state and linearized dynamics

TL;DR

This paper develops a hydrodynamic model for stratified epithelium, revealing how cell proliferation and apoptosis influence tissue stability and dynamics near steady state, with implications for tissue morphology and pattern formation.

Contribution

A novel theoretical framework linking tissue viscoelasticity, cell distribution, and hydrodynamic behavior in stratified epithelium.

Findings

Cell division and apoptosis accelerate relaxation to steady state when proliferative cells are near the basal membrane.

Thick proliferative regions can induce flow and destabilize tissue through apoptosis-induced perturbations.

The model suggests mechanisms for tissue morphology development and pattern formation.

Abstract

A theoretical model for stratified epithelium is presented. The viscoelastic properties of the tissue is assumed to be dependent on the spatial distribution of proliferative and differentiated cells. Based on this assumption, a hydrodynamic description for tissue dynamics at long-wavelength, long-time limit is developed, and the analysis reveals important insight for the dynamics of an epithelium close to its steady state. When the proliferative cells occupy a thin region close to the basal membrane, the relaxation rate towards the steady state is enhanced by cell division and cell apoptosis. On the other hand, when the region where proliferative cells reside becomes sufficiently thick, a flow induced by cell apoptosis close to the apical surface could enhance small perturbations. This destabilizing mechanism is general for continuous self-renewal multi-layered tissues, it could be related to the origin of certain tissue morphology and developing pattern.