Modelling actin polymerization: the effect on confined cell migration

Abstract

The aim of this work is to model cell motility under conditions of mechanical confinement. This cell migration mode may occur in extravasation of tumour and neutrophil-like cells. Cell migration is the result of the complex action of different forces exerted by the interplay between myosin contractility forces and actin processes. Here, we propose and implement a finite element model of the confined migration of a single cell. In this model, we consider the effects of actin and myosin in cell motility. Both filament and globular actin are modelled. We model the cell considering cytoplasm and nucleus with different mechanical properties. The migration speed in the simulation is around 0.1 μm/min, which is in agreement with existing literature. From our simulation, we observe that the nucleus size has an important role in cell migration inside the channel. In the simulation the cell moves further when the nucleus is smaller. However, this speed is less sensitive to nucleus stiffness. The results show that the cell displacement is lower when the nucleus is stiffer. The degree of adhesion between the channel walls and the cell is also very important in confined migration. We observe an increment of cell velocity when the friction coefficient is higher.

Modeling cells spreading, motility, and receptors dynamics: a general framework

“…This approach conforms well for lamellipodia filament networks, although it might result inappropriate for slender and highly oriented microstructures seen in filopodia, which might be better captured by the protrusion-contraction uniaxial tensors presented in Refs. [54,68] or [69]. The following identities can be easily assessed:…”

Unveiling the polarity of actin filaments by cryo-electron tomography

“…Actin filaments (Egelman et al, 1982;Galkin et al, 2015) assemble into complex networks (Malik-Garbi et al, 2019;Xu et al, 2012), which are essential for their activity in the cell. Reconstructing individual actin filaments at sub-nanometer resolution inside cells would provide an unparalleled view on actin networks, and would allow a more fine-grained modeling of cytoskeletal-based mechanical processes (Hervas-Raluy et al, 2019).…”

The role of vimentin-nuclear interactions in persistent cell motility through confined spaces

“…Typical modeling of cells migrating on surfaces involves the actin cortex with actin polymerization driving the leading edge of the cell, adhesion created at the leading edge, adhesion disassembled at the rear, and actinmyosin contraction at the rear as well so that the rear keeps up with the leading edge [10]. More recent surface models exist and do not involve the nucleus [11][12][13][14]. And while such models made progress accurately represent cell speed, predicting cell direction has been more elusive [15].…”