Speaker
Description
Cells can move directionally along gradients of substrate stiffness- a process called durotaxis. In most studied situations, durotaxis relies on cell-substrate focal adhesions to sense stiffness and transmit forces that drive directed motion. Until recently, it was not known whether and how durotaxis could take place in the absence of focal adhesions. However, our experimental collaborators showed that confined cells migrating with the amoeboid mode can migrate directionally up stiffness gradients, despite lacking focal adhesions. We proposed that the mechanism of this focal-adhesion-independent durotaxis is based on the fact that stiffer substrates offer higher friction. Additionally, we put forward a physical model that predicts that the cells polarise and migrate towards regions of higher friction- a process that we call frictiotaxis. Our collaborators then demonstrated frictiotaxis in experiments by showing that the cells can migrate up friction gradients even when stiffness is uniform. Overall, our results show a broader potential of durotaxis to guide cells that contact a substrate, and they reveal a new mode of directed migration based on friction. These findings have implications for cell migration during development, immune response and cancer progression, which usually takes place in confined environments that favour focal-adhesion-independent amoeboid migration.
