title: Modeling the Coupling of Mechanics and Biochemistry in Cell Adhesion
creator: Besser, Achim
subject: ddc-530
subject: 530 Physics
description: The actin cytoskeleton, which is a filament system made of actin biopolymers, mainly determines the mechanical properties of biological cells. In turn, the actin cytoskeleton is itself regulated by various biochemical signaling pathways. To advance the theoretical understanding of this coupling between mechanics and biochemistry, we developed a model for stress fibers which constitute the typical morphology of the actin cytoskeleton in mature cell adhesion. The mechanics of a stress fiber is described by a chain of viscoelastic elements that in addition may locally contract. The initial discrete model is transformed to a partial differential equation by performing a continuum limit. The biochemical regulation is modeled by a system of reaction diffusion equations that couple to the mechanics via the contractile activity along the fiber. In the first part of this thesis, the mechanical stress fiber equation is solved analytically and in particular the complex modulus is exactly calculated. The model is then used for the analysis of experimental data, measured by collaborators in experiments on stress fiber laser nanosurgery. It turns out that stress fibers are considerably crosslinked to their environment and that the localization of certain mechanosensitive proteins correlates with the theoretically predicted stress distribution within the actin cytoskeleton. Finally, the complete model is used to describe cellular behavior on elastic substrates. By performing a bifurcation analysis theoretical predictions are derived that can be tested in future experiments, in particular, the model predicts bistability and hysteresis in cell adhesion.
date: 2009
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/9458/1/PhD_thesis_Achim_Besser.pdf
identifier: DOI:10.11588/heidok.00009458
identifier: urn:nbn:de:bsz:16-opus-94581
identifier:   Besser, Achim  (2009) Modeling the Coupling of Mechanics and Biochemistry in Cell Adhesion.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/9458/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng