title: Single-cell response to stiffness exhibits muscle-like behavior.
abstract: Living cells sense the rigidity of their environment and adapt their activity to it. In particular, cells cultured on elastic substrates align their shape and their traction forces along the direction of highest stiffness and preferably migrate towards stiffer regions. Although numerous studies investigated the role of adhesion complexes in rigidity sensing, less is known about the specific contribution of acto-myosin based contractility. Here we used a custom-made single-cell technique to measure the traction force as well as the speed of shortening of isolated myoblasts deflecting microplates of variable stiffness. The rate of force generation increased with increasing stiffness and followed a Hill force-velocity relationship. Hence, cell response to stiffness was similar to muscle adaptation to load, reflecting the force-dependent kinetics of myosin binding to actin. These results reveal an unexpected mechanism of rigidity sensing, whereby the contractile acto-myosin units themselves can act as sensors. This mechanism may translate anisotropy in substrate rigidity into anisotropy in cytoskeletal tension, and could thus coordinate local activity of adhesion complexes and guide cell migration along rigidity gradients.
authors.affiliation: Laboratoire Matière et Systèmes Complexes, Unité Mixte de Recherche 7057 Centre National de la Recherche Scientifique and Université Paris-Diderot (Paris 7) CC7056-10, Rue A Domont et L Duquet, 75205 Paris Cedex 13, France.
authors.forename: Démosthène
authors.initials: D
authors.lastname: Mitrossilis
authors.forename: Jonathan
authors.initials: J
authors.lastname: Fouchard
authors.forename: Axel
authors.initials: A
authors.lastname: Guiroy
authors.forename: Nicolas
authors.initials: N
authors.lastname: Desprat
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rodriguez
authors.forename: Ben
authors.initials: B
authors.lastname: Fabry
authors.forename: Atef
authors.initials: A
authors.lastname: Asnacios
mesh_terms: D000818:Animals; D002460:Cell Line; D048430:Cell Shape / Q000187:drug effects; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D051379:Mice; D009132:Muscles / Q000166:cytology* / Q000187:drug effects; D032446:Myoblasts / Q000166:cytology* / Q000187:drug effects; D013314:Stress, Mechanical
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; C472645:blebbistatin