title: Contact inhibition of locomotion determines cell-cell and cell-substrate forces in tissues.
abstract: Cells organized in tissues exert forces on their neighbors and their environment. Those cellular forces determine tissue homeostasis as well as reorganization during embryonic development and wound healing. To understand how cellular forces are generated and how they can influence the tissue state, we develop a particle-based simulation model for adhesive cell clusters and monolayers. Cells are contractile, exert forces on their substrate and on each other, and interact through contact inhibition of locomotion (CIL), meaning that cell-cell contacts suppress force transduction to the substrate and propulsion forces align away from neighbors. Our model captures the traction force patterns of small clusters of nonmotile cells and larger sheets of motile Madin-Darby canine kidney (MDCK) cells. In agreement with observations in a spreading MDCK colony, the cell density in the center increases as cells divide and the tissue grows. A feedback between cell density, CIL, and cell-cell adhesion gives rise to a linear relationship between cell density and intercellular tensile stress and forces the tissue into a nonmotile state characterized by a broad distribution of traction forces. Our model also captures the experimentally observed tissue flow around circular obstacles, and CIL accounts for traction forces at the edge.
authors.affiliation: Center for Theoretical Biological Physics, Rice University, Houston, TX 77005;
authors.forename: Juliane
authors.initials: J
authors.lastname: Zimmermann
authors.affiliation: Department of Physics, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Camley
authors.affiliation: Department of Physics, University of California, San Diego, La Jolla, CA 92093.
authors.forename: Wouter-Jan
authors.initials: WJ
authors.lastname: Rappel
authors.affiliation: Center for Theoretical Biological Physics, Rice University, Houston, TX 77005; herbert.levine@rice.edu.
authors.forename: Herbert
authors.initials: H
authors.lastname: Levine
mesh_terms: D000465:Algorithms; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D003198:Computer Simulation; D003260:Contact Inhibition / Q000502:physiology*; D004285:Dogs; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008954:Models, Biological; D014743:Videotape Recording
keywords: collective motility; contact inhibition; tissue mechanics