Biomedical Engineering Reference
In-Depth Information
Chapter 7
Multiscale Mechanochemical Interactions
Between Cell Membrane and Actin Filaments
Mechanochemical and hierarchical interactions are inherent key characteristics of
the actin cytoskeletal system that are vital for the realization of organized cell motile
behavior. This chapter describes a multiscale correlation analysis of the cell peripheral
activity and associated shape changes for a non-polarized epidermal cell. The analy-
sis sheds light on the nature of hierarchical interactions among mechanical factors
as well as biochemical factors, in particular, the effect of membrane curvature on
elongation of the actin filaments during lamellipodial cellular protrusions.
7.1
Introduction
One noteworthy characteristic of the actin cytoskeleton is that its functionality is
regulated by both mechanical and chemical factors (Grosberg et al.
2011
; Adachi
et al.
2009
; Wilson et al.
2010
; Okeyo et al.
2009b
; Miyoshi et al.
2006
). Thus, in
order to understand the mechanism of organized cell motile behavior caused by the
actin cytoskeletal system, it is necessary to understand the hierarchical interactions
involving mechanical factors as well as biochemical factors.
As explained in details in Chap.
1
, actin cytoskeletal system drives cellular
protrusion at the leading edge, which is the first step of cell migration. Migrating
cells
in vivo
exhibit distinct protrusions at the leading edge (Ridley
2011
).
Lamellipodia is a typical example of such protrusive structures. In lamellipodia,
actin polymerization directly pushes the plasma membrane forward.
The focus of this chapter is to elucidate a pathway for the coordination of global
and local cell peripheral activities that lead to lamella-type cellular protrusion:
the formation of a lamellipodium that is a thin, broad and smooth-shaped
protrusive module. First we describe a method of multiscale correlation analysis
aimed at elucidating the hierarchical mechanochemical interaction between
cell membrane and actin filaments. Then, we discuss the relationship between cell
peripheral activity and shape. Finally, mechanochemical and hierarchical feedback
