Math Biology Seminar: Lisanne Rens

  • Date: 08/27/2015
  • Time: 11:00
Lecturer(s):
Lisanne Rens, CWI, Amsterdam and Leiden University
Location: 

University of British Columbia

Topic: 

A model of mechanical cell-extracellular matrix interactions to study self organization on compliant substrates

Description: 

During morphogenesis, the organization of cells into tissues, cells respond to mechanical cues in the extracellular matrix (ECM) but also continuously deform it by pulling on it. To study how traction forces applied by cells influence self organization, we use a computational model, where cells are represented by the Cellular Potts Model. The deformations in the ECM are calculated using a Finite Element Method. We model a mechanical feedback between cells and the ECM, where 1) cells pull on the ECM, 2) strains are generated in the ECM, and 3) cells preferentially extend protrusions oriented with strain. Similar to experiments, cells in our model become small and round on compliant substrates, elongate on substrates of intermediate compliancies and spread on stiff substrates. With just this mechanical cell-substrate feedback in the Cellular Potts Model, simulations show that cells are able to generate vascular like patterns on substrates of intermediate stiffness. Again, this behavior has been observed in experimental conditions as well with cells on compliant substrates. Experiments where the ECM is uniaxially stretched, show that cells orient parallel to stretch. Model results on cells on a stretched ECM with and without traction forces indicate that cell traction forces amplify cell orientation parallel to stretch. Furthermore, they allow cells to organize into strings in the direction of stretch. The ability of cells to form strings is dependent on the balance between stretch force and traction forces. Also, string formation is enhanced when cell-cell adhesion is decreased. The model increases our understanding of how mechanical cell-ECM interactions influence self-organization and may guide tissue engineering experiments.

Other Information: 

Location: Math 126