Dresden 2009 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 17: Poster II

BP 17.6: Poster

Mittwoch, 25. März 2009, 17:15–19:45, P3

Modelling control of cellular force distributions by adhesion geometry and rigidity — •Ilka Bischofs¹, Sebastian Schmidt², and Ulrich Schwarz^2,3 — ¹Lawrence Berkeley Lab, Berkeley, USA — ²University of Heidelberg, Heidelberg, Germany — ³University of Karlsruhe, Karlsruhe, Germany

Adhesion geoemetry and matrix rigidity are important decision factors governing adherent cell morphology and cell differentiation. Both have been shown experimentally to control cellular adhesion forces which affect the status of the cytoskeletal machinery and feed into cell differentiation pathways. Here we present a mechanical contour model based on line and surface tensions that predicts cellular force distributions from the shape and rigidity of the adhesive patterns. For cells constrained to adhesive islands, forces scale with island curvature and preferentially localize to corners. For cells adherent to discrete sites, line tension is the primary force determinant. Forces increase with increasing distance between adhesion sites because surface tension effects result in steeper pulling directions. Substrate compliance counteracts the positive distance effect while the elastic nature of line tension enhances it. The model compares well to experimental observations suggesting that contour forces play an important role in establishing the basic force pattern that might be subsequently amplified by the generation of discrete internal structures such as stress fibers.