Cell division and death inhibit glassy behaviour of confluent tissues

TL;DR

This study models how cell division and death influence the collective behavior of epithelial tissues, revealing that internal activity prevents glassy states and leads to various phases depending on cell turnover and adhesion.

Contribution

It introduces a comprehensive model incorporating cell division, death, and adhesion, demonstrating that tissue activity inhibits glassy behavior and results in multiple dynamic phases.

Findings

Tissue disintegrates at high apoptosis rates.

Multiple phases (gas, gel, dense) depend on cell death/division ratio.

Internal activity prevents the formation of glassy states.

Abstract

We investigate the effects of cell division and apopotosis on collective dynamics in two-dimensional epithelial tissues. Our model includes three key ingredients observed across many epithelia, namely cell-cell adhesion, cell death and a cell division process that depends on the surrounding environment. We show a rich non-equilibrium phase diagram depending on the ratio of cell death to cell division and on the adhesion strength. For large apopotosis rates, cells die out and the tissue disintegrates. As the death rate decreases, however, we show, consecutively, the existence of a gas-like phase, a gel-like phase, and a dense confluent (tissue) phase. Most striking is the observation that the tissue is self-melting through its own internal activity, ruling out the existence of any glassy phase.