Microenvironmental stiffness mediates cytoskeleton re-organization in chondrocytes through laminin-FAK mechanotransduction

Microenvironmental biophysical factors play a fundamental role in controlling cell behaviours, including cell morphology, proliferation, adhesion and differentiation, and even determining the cell fate. Cells can actively sense the surrounding mechanical microenvironment and change their cellular morphology to adapt to it. Although cell morphological changes have been considered the first and most crucial step in the interaction between cells and their mechanical microenvironment, their regulatory network is not completely clear. In the current study, silicon-based elastomer polydimethylsiloxane (PDMS) substrates with stiff and soft stiffnesses, which showed Young’s moduli of ~450 kPa and 46 kPa, respectively, and elucidated a new path in cytoskeleton re-organization in chondrocytes in response to changed substrate stiffnesses by characterizing the axis shift from the secreted extracellular protein laminin β1, focal adhesion complex protein FAK to microfilament bundling were generated.