title: Coherent Motion of Monolayer Sheets under Confinement and Its Pathological Implications.
abstract: Coherent angular rotation of epithelial cells is thought to contribute to many vital physiological processes including tissue morphogenesis and glandular formation. However, factors regulating this motion, and the implications of this motion if perturbed, remain incompletely understood. In the current study, we address these questions using a cell-center based model in which cells are polarized, motile, and interact with the neighboring cells via harmonic forces. We demonstrate that, a simple evolution rule in which the polarization of any cell tends to orient with its velocity vector can induce coherent motion in geometrically confined environments. In addition to recapitulating coherent rotational motion observed in experiments, our results also show the presence of radial movements and tissue behavior that can vary between solid-like and fluid-like. We show that the pattern of coherent motion is dictated by the combination of different physical parameters including number density, cell motility, system size, bulk cell stiffness and stiffness of cell-cell adhesions. We further observe that perturbations in the form of cell division can induce a reversal in the direction of motion when cell division occurs synchronously. Moreover, when the confinement is removed, we see that the existing coherent motion leads to cell scattering, with bulk cell stiffness and stiffness of cell-cell contacts dictating the invasion pattern. In summary, our study provides an in-depth understanding of the origin of coherent rotation in confined tissues, and extracts useful insights into the influence of various physical parameters on the pattern of such movements.
authors.affiliation: Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: S S
authors.initials: SS
authors.lastname: Soumya
authors.affiliation: Department of Physics, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Animesh
authors.initials: A
authors.lastname: Gupta
authors.affiliation: DICAM-Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Cugno
authors.affiliation: DICAM-Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Deseri
authors.affiliation: Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Dayal
authors.affiliation: Department of Physics, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Dibyendu
authors.initials: D
authors.lastname: Das
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Shamik
authors.initials: S
authors.lastname: Sen
authors.affiliation: Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai, India.
authors.forename: Mandar M
authors.initials: MM
authors.lastname: Inamdar
mesh_terms: D000818:Animals; D002449:Cell Aggregation / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D003198:Computer Simulation; D004548:Elasticity / Q000502:physiology; D004847:Epithelial Cells / Q000166:cytology / Q000502:physiology*; D022001:Focal Adhesions / Q000502:physiology*; D006801:Humans; D040542:Mechanotransduction, Cellular / Q000502:physiology; D008954:Models, Biological; D009361:Neoplasm Invasiveness / Q000503:physiopathology