Theory of cell size regulation during migration in adhered cells

TL;DR

This paper develops a minimal theoretical model linking cell size regulation to migration velocity, emphasizing the roles of membrane potential and actin forces, and explains experimental observations in neutrophils.

Contribution

It introduces a novel theoretical framework connecting cell size dynamics with migration, highlighting the importance of size-dependent force inhomogeneities for cell polarization.

Findings

Cell size influences migration ability through force inhomogeneities.

A critical contact area exists, beyond which migration occurs.

The model explains observed volume changes in neutrophils during migration.

Abstract

Cell migration is closely linked to cell shape, yet cell size is often assumed to remain constant. This assumption is challenged by recent experiments showing that cells undergo volume loss during spreading and swelling upon activation, with migration velocity correlated to cell size. In this Letter, we present a minimal theoretical framework for cellular size regulation and its influence on migration velocity. We connect cell size to membrane potential and active, actin-driven forces. Spatial inhomogeneities in these forces establish cell polarization and drive migration. Crucially, inhomogeneity is easier to establish over larger sizes, giving rise to a critical contact area, above which migration is possible. Our theory captures the coupled dynamics of cell volume, surface area, and motility and explains recent experiments on neutrophils.