Bob McMeeking: Mechano-sensitive feedback between intracellularsignalling, focal adhesion development and stress-fibre contractility

1st of April 2015, Chichley Hall

In his talk Bob McMeeking started off explaining the experimental work by Christopher Chen's group underpinning his model. If cells are placed on small, soft, polymer pillars they are able to deform these by pulling (Tan et al. PNAS 2004). These deformations can be readily transformed into forces exerted at these points. At the same time, or after the experiment, the organisation of the F-actin and myosin cytoskeleton can be analysed.  Others have shown that there is a feedback between the organisation of the cytoskeleton and the force that is being exerted. Some of the underlying biochemistry is well known so that the model developed includes diffusion mechanisms to overcome locally diminished concentrations of precursor molecules (F-actin, activated myosin, ...). It also includes the steps needed to activate myosin contractility as well as self assembly of contractile subunits. Overall the model arrives at solutions that resemble the F-actin fibre arrangements and the forces observed in the experiments mentioned above. The predicted change in force distribution when the cells covered a larger number of pillars served as supporting evidence for the validity of the model. 

The paper underpinning much of this talk: A Bio-Chemo-Mechanical Model for Cell Contractility, PNAS USA, 103, 2006, 14015-14020, V.S. Deshpande, R.M. McMeeking and A.G. Evans

More about Bob McMeeking and his work: http://engineering.ucsb.edu/faculty/profile/204

This talk was part of a workshop on "Cell Mechanobiology" organised by Rene de Borst, which took place April 1st and 2nd 2015, with support by the Royal Society at Chicheley Hall. for the programme details see: http://bio-mat-sketches-mor.blogspot.co.uk/2015/04/cell-mechanobiology-workshop-1st-2nd.html