An Extended Filament Based Lamellipodium Model Produces Various Moving Cell Shapes in the Presence of Chemotactic Signals

TL;DR

This paper extends the Filament Based Lamellipodium Model to include additional biological processes and demonstrates its ability to simulate various cell shapes and movements in response to chemotactic signals.

Contribution

The paper introduces an extended FBLM incorporating filament nucleation, capping, contraction, and repulsion, enabling more realistic simulation of cell motility and shape changes.

Findings

Model can simulate various cell shapes and movements.

Predicts transitions between stationary and motile states.

Shows response to chemotactic signals in simulations.

Abstract

The Filament Based Lamellipodium Model (FBLM) is a two-phase two-dimensional continuum model, describing the dynamcis of two interacting families of locally parallel actin filaments (C.Schmeiser and D.Oelz, How do cells move? Mathematical modeling of cytoskeleton dynamics and cell migration. Cell mechanics: from single scale-based models to multiscale modeling. Chapman and Hall, 2010). It contains accounts of the filaments' bending stiffness, of adhesion to the substrate, and of cross-links connecting the two families. An extension of the model is presented with contributions from nucleation of filaments by branching, from capping, from contraction by actin-myosin interaction, and from a pressure-like repulsion between parallel filaments due to Coulomb interaction. The effect of a chemoattractant is described by a simple signal transduction model influencing the polymerization speed. Simulations with the extended model show its potential for describing various moving cell shapes, depending on the signal transduction procedure, and for predicting transients between nonmoving and moving states as well as changes of direction.