change of time - prof. McMeeking's seminar

[Emanuele Tuillier Illingworth]

SISSA MATHLAB SEMINAR ANNOUNCEMENT


Robert McMeeking (University of California - Santa Barbara)

Date: Monday, 8 July, 2013 - 11:30

Room: 133

Title: Adhesion of cells and the influence of cytoskeletal contractility

Abstract: Almost all eukaryotic cells are capable of adhering to an
extra-cellular matrix, to other cells, to hard and soft tissue and to
artificial substrates, e.g. coated glass slides. Such adhesion occurs by
specific and non-specific interactions between substrate ligands and
cellular trans-membrane protein complexes. An additional phenomenon that
is often coupled to cellular adhesion is cytoskeletal contractility
driven by protein motors, with the commonest example being that due to
myosin cross-bridging with actin filaments. Cases include smooth muscle
cells, fibroblasts, endothelial cells and cardiac muscle cells.
Observations indicate that the size of adhesive protein complexes, known
as focal adhesions, is proportional to the degree of cell contractility,
and the magnitude of the forces applied are also similarly controlled.
Such phenomena have been incorporated into a chemo-mechanical model for
cell adhesions interacting with ligands that are subject to contractile
forces from the cytoskeleton. This model has been used successfully to
simulate various cellular phenomena. These include the sensitivity of
cell contractile forces to substrate stiffness, the orientation of
cytoskeletal stress-fibres in smooth muscle cells that are cyclically
stretched, and the location of focal adhesions and stress-fibers in
cells adhering to patterned shapes of fibronectin, a ligand bearing
protein. The model is also used to simulate the process of a spherical
cell developing adhesion to a flat surface, and the shearing of an
adhered cell on a flat surface where the cell body is forced sideways by
a blunt tool.