How do Single-Cell Properties Influence the Collective Mechanical Behavior of Confluent Tissues?

Abstract

Biological tissues involved in important processes such as embryonic development, lung function, wound healing, and cancer progression have recently been shown, via a systematic analysis of tissue mechanics and cell displacement statistics, to be close to a disordered liquid-to-solid or “jamming” transition. We expect these jamming transitions to be very important for biological function. For example, due to collective effects, cell migration is greatly reduced in solid-like tissues and enhanced in fluid-like tissues. Therefore, we would like to know how cells might regulate properties such as expression of cell-cell adhesion molecules and myosin activity in order to change the macroscopic properties of the tissue as a whole. I will discuss a new theoretical framework that predicts how the jamming transition is governed by single-cell mechanics and persistent cell motility. I will discuss how our a priori theoretical predictions with no fit parameters are precisely realized in cell cultures from human patients with asthma, and discuss how these ideas might also be applied in heterogeneous cell populations to understand processes in embryonic development and cancer progression.