Biomedical Engineering Reference
In-Depth Information
7.6.2
Coordination of Global and Local Cell
Peripheral Motility
Polarized crescent-shaped keratocytes have been often used for investigations of the
mechanochemical interactions to maintain the leading edge protrusion tightly cou-
pled with the trailing edge retraction (Barnhart et al.
2010
). As explained in Chap.
the positive feedback loop to drive highly polarized migration (Adachi et al.
2009
;
Okeyo et al.
2009b
). Myoshi-II-driven network disassembly contributes to the
long-range coordination of the actin network over the distance scale of a whole cell
(Wilson et al.
2010
). As well, a model that the simple elastic coupling between
movement at the front of the cell and that at the rear achieves the mechanical
integration has been proposed (Barnhart et al.
2010
).
In addition to the mechanism of the global coordination of the actin cytoskel-
etal system over a whole cell, the global and local coordination mechanism is
involved in realizing organized cell migration. The correlation between the cell
peripheral activity and cell peripheral shape depending on the combination of
the global and local characteristics of the cell peripheral activities (Figs.
7.5
,
7.6
, and
7.7
) suggests a pathway to coordinate the global cell peripheral activity
with more local cell peripheral activity. The cell peripheral shape, more specifi-
cally, cell peripheral curvature at the scale of a few micrometers, is a significant
factor in the pathway.
7.7
Conclusion
This chapter has discussed the characteristics and the dynamics of coordinated
lamellar-type cellular protrusion. The analysis has shed light on the mechanochem-
ical pathway in which actin filament elongation under the membrane and the mem-
brane curvature or curvature related factors affect each other to regulate the
subcellular peripheral activity in combination with the global cellular peripheral
activity. This knowledge about the mechanochemical pathway that regulates cel-
lular protrusion, which is the first step of cell migration, should promote under-
standing how cells sense the extracellular environmental stimuli, especially
physical properties, such as micro-/nano-topography and stiffness of the extracel-
lular matrix. In terms of biomedical applications, the findings here provide a theo-
retical concept for techniques to control (Miyoshi et al.
2010
; Ambravaneswaran
et al.
2010
; Miyoshi and Adachi
2012
) and reconstruct (Dayel et al.
2009
; Smith
2010
; Murrell et al.
2011
; Paluch et al.
2005
) cell motile behavior. We also envision
that the simple integrative analytical methodology presented here is generally ben-
eficial to focus on the integrating the intra- and inter-scale interactions across many
processes on various spatiotemporal scales, and further clarify the structure and
dynamics of a given system of interest.
