Force mapping in epithelial cell migration

Abstract

We measure dynamic traction forces exerted by epithelial cells on a substrate. The force sensor is a high-density array of elastomeric microfabricated pillars that support the cells. Traction forces induced by cell migration are deduced from the measurement of the bending of these pillars and are correlated with actin localization by fluorescence microscopy. We use a multiple-particle tracking method to estimate the mechanical activity of cells in real time with a high-spatial resolution (down to 2 μm) imposed by the periodicity of the post array. For these experiments, we use differentiated Madin-Darby canine kidney (MDCK) epithelial cells. Our data provide definite information on mechanical forces exerted by a cellular assembly. The maximum intensity of the forces is localized on the edge of the epithelia. Hepatocyte growth factor promotes cell motility and induces strong scattering activity of MDCK cells. Thus, we compare forces generated by MDCK cells in subconfluent epithelia versus isolated cells after hepatocyte growth factor treatment. Maximal-traction stresses at the edge of a monolayer correspond to higher values than those measured for a single cell and may be due to a collective behavior

Determinants of cell–material crosstalk at the interface: towards engineering of cell instructive materials

“…The first experimental evidence of mechanosensing dates back more than 30 years when Harris et al [91] reported and measured cell contractile forces on flexible rubber membranes. Numerous other studies have followed this first report especially focused on developing systems to analyse the dynamics of cell-generated forces [92][93][94]. These forces fall within the 1 pN -1 nN Table 2.…”

Collective cell traction force analysis on aligned smooth muscle cell sheet between three-dimensional microwalls

“…Recent advances in the development of two-dimensional model systems for studying cell-substrate mechanics of single cells have been reported by several groups [23,24,[37][38][39]. Among various biomaterials, polyacrylamide-based hydrogel (PAG), which can be engineered with variable chemical and mechanical properties, has proved to be an ideal experimental system for such study [40].…”

“…cell sheet, which is actually involved in major biological processes such as morphogenesis, wound healing and tissue repair is not thoroughly understood [19][20][21]. A recent study has shown that the distribution and magnitude of the CTF concentrates on the periphery of the cell colony on planar substrates [22,23]. Another study of an advancing epithelial cell sheet has demonstrated that the CTF in at its leading edge during migration is predominately driven by cells at the rear end instead of those at the leading edge [24].…”

Migration collective : un partage des tâches entre cellulesleaderset coordination supracellulaire

“…Nous avons corrélé deux types essentiels d'informations ( Figure 1) : les forces dévelop-pées par les cellules sur le substrat et l'activité des RhoGTPases dans le plan basal des cellules. Les cellules sont déposées sur un tapis de micropiliers dont la déflexion renseigne sur les forces mises en jeu (amplitude et direction), ce qui permet d'obtenir une carte dynamique des forces [9]. Des biosenseurs moléculaires [10], dont la détection est basée sur une technique FRET (fluorescence resonance energy transfer), sont utilisés afin de déterminer l'activité des RhoGTPases RhoA et Rac1.…”

“…Ces sondes renseignent sur la conformation des GTPases via l'interaction intramoléculaire de deux fluorophores. Les forces sont mesurées par la déflexion des piliers souples sur lesquels les cellules migrent [9]. La position du sommet de ces piliers (proportionnelle à la force qui y est appliquée) est mesurée en fluorescence sur le canal rouge (Cy5).…”