Hysteresis in the cell response to time-dependent substrate stiffness

A. Besser and U.S. Schwarz, Biophys. J. 99: L10-L12, 2010

Mechanical cues like the rigidity of the substrate are main
determinants for the decision making of adherent cells. Here we use
a mechano-chemical model to predict the cellular response to varying
substrate stiffness. The model equations combine the mechanics of
contractile actin filament bundles with a model for the
Rho-signaling pathway triggered by forces at cell-matrix contacts.
A bifurcation analysis of cellular contractility as a function of
substrate stiffness reveals a bistable response, thus defining a
lower threshold of stiffness, below which cells are not able to
build up contractile forces, and an upper threshold of stiffness,
above which cells are always in a strongly contracted state. Using
the full dynamical model, we predict that rate-dependent hysteresis
will occur in the cellular traction forces when cells are exposed to
substrates of time-dependent stiffness.