Poster Presentation 2014 International Biophysics Congress

Probing the role of spatial anisotropy and heterogeneity in contractility and adhesion distribution during cell steering (#386)

Soumya S S 1 , Subodh Kolwankar 1 , Edna George 1 , Santanu K Basu 1 , Shamik Sen 1 , Mandar Inamdar 1
  1. Indian Institute of Technology Bombay, Mumbai, India

Cell motility is central to various processes including embryogenesis and wound healing. For efficient migration, close temporal and spatial co-ordination between the cytoskeleton and the focal adhesions is essential. Since both the cytoskeleton and the adhesions contribute to motility, their relative contributions to a cell’s frequent directional changes remain unclear. Tensional homeostasis, or force balance between the cytoskeleton and the focal adhesions, can be gauged using the trypsin de-adhesion assay wherein, cell retraction is tracked upon rapidly severing cell-matrix contacts using the enzyme trypsin. Upon incubation with trypsin, in addition to the sigmoidal retraction kinetics observed in a variety of adherent cells, 3T3 fibroblasts were found to exhibit a combination of translation and rotation while rounding up. Such motions may arise from a combination of anisotropy in cell contractility (or, prestress) and cell-matrix adhesions, and may be associated with frequent directional changes associated with random cell motility. In this study, we propose a simple theoretical model, which can replicate the above-mentioned cell dynamics, and evaluate the relative contributions of anisotropy in contractility and bond distribution. Various combinations of bond distribution and prestress were applied to the cell and then using finite element analysis, its translation and rotation upon trypsin assisted de-adhesion were examined in each case. The results of our study indicate that while asymmetry in bond distribution causes only cell translation, a combination of asymmetric bond distribution and non-uniform contractility are required for translation and rotation, and may guide cell migration.1 1 

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