seminaire - LMGP - 15/06/2016 - Brendon BAKER

Cell-mediated fibre recruitment drives extracellular matrix mechanosensing in engineered fibrillar microenvironments

Associate Pr, Brendon Baker

Dpt of Biomedical Engineering, University of Michigan
 

Abstract

To investigate how cells sense stiffness in settings structurally similar to native extracellular

matrices, we designed a synthetic fibrous material with tunable mechanics and user-defined

architecture. In contrast to flat hydrogel surfaces, these fibrous materials recapitulated cell-matrix

interactions observed with collagen matrices including stellate cell morphologies, cell-mediated

realignment of fibres, and bulk contraction of the material. Increasing the stiffness of flat hydrogel

surfaces induced mesenchymal stem cell spreading and proliferation; however, increasing fibre

stiffness instead suppressed spreading and proliferation for certain network architectures. Lower

fibre stiffness permitted active cellular forces to recruit nearby fibres, dynamically increasing

ligand density at the cell surface and promoting the formation of focal adhesions and related

signalling. These studies demonstrate a departure from the well-described relationship between

material stiffness and spreading established with hydrogel surfaces, and introduce fibre

recruitment as a previously undescribed mechanism by which cells probe and respond to

mechanics in fibrillar matrices.

mise à jour le 12 juin 2016