title: Force transmission during adhesion-independent migration.
abstract: When cells move using integrin-based focal adhesions, they pull in the direction of motion with large, ∼100 Pa, stresses that contract the substrate. Integrin-mediated adhesions, however, are not required for in vivo confined migration. During focal adhesion-free migration, the transmission of propelling forces, and their magnitude and orientation, are not understood. Here, we combine theory and experiments to investigate the forces involved in adhesion-free migration. Using a non-adherent blebbing cell line as a model, we show that actin cortex flows drive cell movement through nonspecific substrate friction. Strikingly, the forces propelling the cell forward are several orders of magnitude lower than during focal-adhesion-based motility. Moreover, the force distribution in adhesion-free migration is inverted: it acts to expand, rather than contract, the substrate in the direction of motion. This fundamentally different mode of force transmission may have implications for cell-cell and cell-substrate interactions during migration in vivo.
authors.affiliation: 1] MRC Laboratory for Molecular Cell Biology, UCL, London WC1E 6BT, UK [2] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Bergert
authors.affiliation: Max Planck Institute for the Physics of Complex Systems, Dresden 01187, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Erzberger
authors.affiliation: 1] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK [2] MRC National Institute for Medical Research, London NW7 1AA, UK [3] Department of Cell and Developmental Biology, UCL, London WC1E 6BT, UK.
authors.forename: Ravi A
authors.initials: RA
authors.lastname: Desai
authors.affiliation: 1] MRC Laboratory for Molecular Cell Biology, UCL, London WC1E 6BT, UK [2] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK.
authors.forename: Irene M
authors.initials: IM
authors.lastname: Aspalter
authors.affiliation: 1] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK [2] MRC National Institute for Medical Research, London NW7 1AA, UK [3] Department of Cell and Developmental Biology, UCL, London WC1E 6BT, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Oates
authors.affiliation: 1] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK [2] London Centre for Nanotechnology and Department of Cell and Developmental Biology, UCL, London WC1H 0AH, UK.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Charras
authors.affiliation: Max Planck Institute for the Physics of Complex Systems, Dresden 01187, Germany.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Salbreux
authors.affiliation: 1] MRC Laboratory for Molecular Cell Biology, UCL, London WC1E 6BT, UK [2] Institute for the Physics of Living Systems, UCL, London WC1E 6BT, UK.
authors.forename: Ewa K
authors.initials: EK
authors.lastname: Paluch
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002279:Carcinoma 256, Walker; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D017276:Friction / Q000502:physiology*; D016023:Integrins / Q000378:metabolism; D051381:Rats; D013314:Stress, Mechanical
chemical_list: D000199:Actins; D016023:Integrins