title: Protrusion fluctuations direct cell motion.
abstract: Many physiological phenomena involve directional cell migration. It is usually attributed to chemical gradients in vivo. Recently, other cues have been shown to guide cells in vitro, including stiffness/adhesion gradients or micropatterned adhesive motifs. However, the cellular mechanism leading to these biased migrations remains unknown, and, often, even the direction of motion is unpredictable. In this study, we show the key role of fluctuating protrusions on ratchet-like structures in driving NIH3T3 cell migration. We identified the concept of efficient protrusion and an associated direction index. Our analysis of the protrusion statistics facilitated the quantitative prediction of cell trajectories in all investigated conditions. We varied the external cues by changing the adhesive patterns. We also modified the internal cues using drug treatments, which modified the protrusion activity. Stochasticity affects the short- and long-term steps. We developed a theoretical model showing that an asymmetry in the protrusion fluctuations is sufficient for predicting all measures associated with the long-term motion, which can be described as a biased persistent random walk.
authors.affiliation: Laboratory of Cell Physics, Institut de Science et d'Ingénierie Supramoléculaires/Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg and Centre National de la Recherche Scientifique UMR 7006, Strasbourg, France; Development and Stem Cells Program, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale (U964),Université de Strasbourg, Illkirch, France.
authors.forename: David
authors.initials: D
authors.lastname: Caballero
authors.affiliation: Laboratoire de Physique Théorique de la Matière Condensée, Centre National de la Recherche Scientifique UMR 7600; Laboratoire Jean Perrin, Centre National de la Recherche Scientifique UMR 823, Université Pierre et Marie Curie, Paris, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Voituriez
authors.affiliation: Laboratory of Cell Physics, Institut de Science et d'Ingénierie Supramoléculaires/Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg and Centre National de la Recherche Scientifique UMR 7006, Strasbourg, France; Development and Stem Cells Program, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique UMR 7104, Institut National de la Santé et de la Recherche Médicale (U964),Université de Strasbourg, Illkirch, France. Electronic address: riveline@unistra.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Riveline
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D022081:Cell Surface Extensions / Q000502:physiology*; D051379:Mice; D008954:Models, Biological; D041681:NIH 3T3 Cells; D013269:Stochastic Processes