Extra-cellular Matrix in cell aggregates is a proxy to mechanically control cell proliferation and motility

Abstract

Imposed deformations play an important role in morphogenesis and tissue homeostasis, both in normal and pathological conditions. To perceive mechanical perturbations of different types and magnitudes, tissues need appropriate detectors, with a compliance that matches the perturbation amplitude. By comparing results of selective osmotic compressions of cells within multicellular aggregates with small osmolites and global aggregate compressions with big osmolites, we show that global compressions have a strong impact on the aggregates growth and internal cell motility, while selective compressions of same magnitude have almost no effect. Both compressions alter the volume of individual cells in the same way but, by draining the water out of the extracellular matrix, the global one imposes a residual compressive mechanical stress on the cells while the selective one does not. We conclude that, in aggregates, the extracellular matrix is as a sensor which mechanically regulates cell proliferation and migration in a 3D environment.