External seminar - Charlie Duclut (Institut Curie/Sorbonne Université)

In addition to generating forces and reacting to mechanical cues, cells are capable of actively pumping fluid by transporting charged ions. In multicellular systems, this hydraulic activity is for instance crucial for the formation and growth of fluid-filled cavities (or lumens).
In the first part of this talk, I will propose a simple continuum model that recapitulates the behaviour of MDCK cells grown on hydrogel spheres. I will show that cell pumping, rather than cell contractility, is responsible for important compressive stresses. I will discuss how the interplay between tissue hydraulics, mechanics, and proliferation needs to be considered in order to understand the behaviour of this multicellular system.
In the second part, I will discuss -- from a theoretical perspective -- how a hydraulic or electrical perturbation, imposed for instance by a drain of micrometric diameter, could be used to perturb tissue growth. I will discuss and quantify the effect of electrohydraulic perturbations on the long-time states of the tissue. I will highlight that a moderate external pumping or electric current can drive a proliferating spheroid to decay.