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Cammarota C, Dawney NS, Bellomio PM, Jüng M, Fletcher AG, Finegan TM, Bergstralh DT. The mechanical influence of densification on epithelial architecture. PLoS Comput Biol 2024; 20:e1012001. [PMID: 38557605 PMCID: PMC11008847 DOI: 10.1371/journal.pcbi.1012001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 04/11/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024] Open
Abstract
Epithelial tissues are the most abundant tissue type in animals, lining body cavities and generating compartment barriers. The function of a monolayered epithelial tissue-whether protective, secretory, absorptive, or filtrative-relies on the side-by-side arrangement of its component cells. The mechanical parameters that determine the shape of epithelial cells in the apical-basal plane are not well-understood. Epithelial tissue architecture in culture is intimately connected to cell density, and cultured layers transition between architectures as they proliferate. This prompted us to ask to what extent epithelial architecture emerges from two mechanical considerations: A) the constraints of densification and B) cell-cell adhesion, a hallmark feature of epithelial cells. To address these questions, we developed a novel polyline cell-based computational model and used it to make theoretical predictions about epithelial architecture upon changes to density and cell-cell adhesion. We tested these predictions using cultured cell experiments. Our results show that the appearance of extended lateral cell-cell borders in culture arises as a consequence of crowding-independent of cell-cell adhesion. However, cadherin-mediated cell-cell adhesion is associated with a novel architectural transition. Our results suggest that this transition represents the initial appearance of a distinctive epithelial architecture. Together our work reveals the distinct mechanical roles of densification and adhesion to epithelial layer formation and provides a novel theoretical framework to understand the less well-studied apical-basal plane of epithelial tissues.
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Affiliation(s)
- Christian Cammarota
- Department of Physics and Astronomy, University of Rochester, Rochester, New York, United States of America
| | - Nicole S. Dawney
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Philip M. Bellomio
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Maren Jüng
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Alexander G. Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
| | - Tara M. Finegan
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Dan T. Bergstralh
- Department of Physics and Astronomy, University of Rochester, Rochester, New York, United States of America
- Department of Biology, University of Rochester, Rochester, New York, United States of America
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States of America
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2
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Wu Y, Sun SX. Mechanics of cell-cell junctions. Biophys J 2023; 122:3354-3368. [PMID: 37475215 PMCID: PMC10465726 DOI: 10.1016/j.bpj.2023.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/01/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023] Open
Abstract
Tissue cells in epithelial or endothelial monolayers are connected through cell-cell junctions, which are stabilized by transmembrane E-cadherin bonds and intracellular actin filaments. These bonds and junctions play a crucial role in maintaining the barrier function of epithelia and endothelia and are believed to transmit forces between cells. Additionally, E-cadherin bonds can impact the shape of cell-cell junctions. In this study, we develop a continuum mechanical model of the cell-cell junction by explicitly incorporating the cell membrane, distributions of E-cadherin bonds, cytoplasmic fluid pressure, and F-actin dynamics. The static force-balanced version of the model is able to analyze the influences of cell cortical tension, actin dynamics, and cytoplasmic pressure on the junction shape and E-cadherin bonds. Furthermore, an extended model that incorporates fluid flow, across the cell boundary as well as around the cell, is also examined. This model can couple cell-shape changes with cell cortical tension and fluid flow, and predicts the additional effect of fluid motion on cell-cell junction mechanics. Taken together, our models serve as an intermediate link between molecular-scale models of cell-junction molecules and cell-scale models of tissue and epithelia.
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Affiliation(s)
- Yufei Wu
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland
| | - Sean X Sun
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, Maryland; Center for Cell Dynamics, Johns Hopkins School of Medicine, Baltimore, Maryland.
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3
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Jain HP, Voigt A, Angheluta L. Robust statistical properties of T1 transitions in a multi-phase field model of cell monolayers. Sci Rep 2023; 13:10096. [PMID: 37344548 DOI: 10.1038/s41598-023-37064-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/15/2023] [Indexed: 06/23/2023] Open
Abstract
Large-scale tissue deformation which is fundamental to tissue development hinges on local cellular rearrangements, such as T1 transitions. In the realm of the multi-phase field model, we analyse the statistical and dynamical properties of T1 transitions in a confluent monolayer. We identify an energy profile that is robust to changes in several model parameters. It is characterized by an asymmetric profile with a fast increase in energy before the T1 transition and a sudden drop after the T1 transition, followed by a slow relaxation. The latter being a signature of the fluidity of the cell monolayer. We show that T1 transitions are sources of localised large deformation of the cells undergoing the neighbour exchange, and they induce other T1 transitions in the nearby cells leading to a chaining of events that propagate local cell deformation to large scale tissue flows.
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Affiliation(s)
- Harish P Jain
- Njord Centre, Department of Physics, University of Oslo, 0371, Oslo, Norway.
| | - Axel Voigt
- Institute of Scientific Computing, Technische Universität Dresden, 01062, Dresden, Germany
- Center of Systems Biology Dresden, Pfotenhauerstr. 108, 01307, Dresden, Germany
- Cluster of Excellence - Physics of Life, TU Dresden, 01062, Dresden, Germany
| | - Luiza Angheluta
- Njord Centre, Department of Physics, University of Oslo, 0371, Oslo, Norway
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4
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Cammarota C, Dawney NS, Bellomio PM, Jüng M, Fletcher AG, Finegan TM, Bergstralh DT. The Mechanical Influence of Densification on Initial Epithelial Architecture. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.07.539758. [PMID: 37214914 PMCID: PMC10197549 DOI: 10.1101/2023.05.07.539758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Epithelial tissues are the most abundant tissue type in animals, lining body cavities and generating compartment barriers. The function of a monolayer epithelium - whether protective, secretory, absorptive, or filtrative -relies on regular tissue architecture with respect to the apical-basal axis. Using an unbiased 3D analysis pipeline developed in our lab, we previously showed that epithelial tissue architectures in culture can be divided into distinct developmental categories, and that these are intimately connected to cell density: at sparse densities, cultured epithelial cell layers have a squamous morphology (Immature); at intermediate densities, these layers develop lateral cell-cell borders and rounded cell apices (Intermediate); cells at the highest densities reach their full height and demonstrate flattened apices (Mature). These observations prompted us to ask whether epithelial architecture emerges from the mechanical constraints of densification, and to what extent a hallmark feature of epithelial cells, namely cell-cell adhesion, contributes. In other words, to what extent is the shape of cells in an epithelial layer a simple matter of sticky, deformable objects squeezing together? We addressed this problem using a combination of computational modeling and experimental manipulations. Our results show that the first morphological transition, from Immature to Intermediate, can be explained simply by cell crowding. Additionally, we identify a new division (and thus transition) within the Intermediate category, and find that this second morphology relies on cell-cell adhesion.
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Affiliation(s)
- Christian Cammarota
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA
| | - Nicole S Dawney
- Department of Biology, University of Rochester, Rochester, NY, USA
| | | | - Maren Jüng
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, UK
- Bateson Centre, University of Sheffield, Sheffield, UK
| | - Tara M Finegan
- Department of Biology, University of Rochester, Rochester, NY, USA
| | - Dan T Bergstralh
- Department of Physics and Astronomy, University of Rochester, Rochester, NY, USA
- Department of Biology, University of Rochester, Rochester, NY, USA
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY, USA
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5
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Kim S, Pochitaloff M, Stooke-Vaughan GA, Campàs O. Embryonic Tissues as Active Foams. NATURE PHYSICS 2021; 17:859-866. [PMID: 34367313 PMCID: PMC8336761 DOI: 10.1038/s41567-021-01215-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The physical state of embryonic tissues emerges from non-equilibrium, collective interactions among constituent cells. Cellular jamming, rigidity transitions and characteristics of glassy dynamics have all been observed in multicellular systems, but it is unclear how cells control these emergent tissue states and transitions, including tissue fluidization. Combining computational and experimental methods, here we show that tissue fluidization in posterior zebrafish tissues is controlled by the stochastic dynamics of tensions at cell-cell contacts. We develop a computational framework that connects cell behavior to embryonic tissue dynamics, accounting for the presence of extracellular spaces, complex cell shapes and cortical tension dynamics. We predict that tissues are maximally rigid at the structural transition between confluent and non-confluent states, with actively-generated tension fluctuations controlling stress relaxation and tissue fluidization. By directly measuring strain and stress relaxation, as well as the dynamics of cell rearrangements, in elongating posterior zebrafish tissues, we show that tension fluctuations drive active cell rearrangements that fluidize the tissue. These results highlight a key role of non-equilibrium tension dynamics in developmental processes.
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Affiliation(s)
- Sangwoo Kim
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Marie Pochitaloff
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
| | | | - Otger Campàs
- Department of Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
- Center for Bioengineering, University of California, Santa Barbara, CA 93106, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
- California NanoSystems Institute, University of California, Santa Barbara, CA 93106, USA
- Cluster of Excellence Physics of Life, TU Dresden, 01062 Dresden, Germany
- Correspondence should be addressed to Otger Camps ()
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6
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Loerke D, Blankenship JT. Viscoelastic voyages - Biophysical perspectives on cell intercalation during Drosophila gastrulation. Semin Cell Dev Biol 2019; 100:212-222. [PMID: 31784092 DOI: 10.1016/j.semcdb.2019.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 09/11/2019] [Accepted: 11/11/2019] [Indexed: 12/18/2022]
Abstract
Developmental processes are driven by a combination of cytoplasmic, cortical, and surface-associated forces. However, teasing apart the contributions of these forces and how a viscoelastic cell responds has long been a key question in developmental biology. Recent advances in applying biophysical approaches to these questions is leading to a fundamentally new understanding of morphogenesis. In this review, we discuss how computational analysis of experimental findings and in silico modeling of Drosophila gastrulation processes has led to a deeper comprehension of the physical principles at work in the early embryo. We also summarize many of the emerging methodologies that permit biophysical analysis as well as those that provide direct and indirect measurements of force directions and magnitudes. Finally, we examine the multiple frameworks that have been used to model tissue and cellular behaviors.
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Affiliation(s)
- Dinah Loerke
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA.
| | - J Todd Blankenship
- Department of Biological Sciences, University of Denver, Denver, CO 80208, USA.
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7
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Wolff HB, Davidson LA, Merks RMH. Adapting a Plant Tissue Model to Animal Development: Introducing Cell Sliding into VirtualLeaf. Bull Math Biol 2019; 81:3322-3341. [PMID: 30927191 PMCID: PMC6677868 DOI: 10.1007/s11538-019-00599-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 03/11/2019] [Indexed: 11/16/2022]
Abstract
Cell-based, mathematical modeling of collective cell behavior has become a prominent tool in developmental biology. Cell-based models represent individual cells as single particles or as sets of interconnected particles and predict the collective cell behavior that follows from a set of interaction rules. In particular, vertex-based models are a popular tool for studying the mechanics of confluent, epithelial cell layers. They represent the junctions between three (or sometimes more) cells in confluent tissues as point particles, connected using structural elements that represent the cell boundaries. A disadvantage of these models is that cell-cell interfaces are represented as straight lines. This is a suitable simplification for epithelial tissues, where the interfaces are typically under tension, but this simplification may not be appropriate for mesenchymal tissues or tissues that are under compression, such that the cell-cell boundaries can buckle. In this paper, we introduce a variant of VMs in which this and two other limitations of VMs have been resolved. The new model can also be seen as on off-the-lattice generalization of the Cellular Potts Model. It is an extension of the open-source package VirtualLeaf, which was initially developed to simulate plant tissue morphogenesis where cells do not move relative to one another. The present extension of VirtualLeaf introduces a new rule for cell-cell shear or sliding, from which cell rearrangement (T1) and cell extrusion (T2) transitions emerge naturally, allowing the application of VirtualLeaf to problems of animal development. We show that the updated VirtualLeaf yields different results than the traditional vertex-based models for differential adhesion-driven cell sorting and for the neighborhood topology of soft cellular networks.
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Affiliation(s)
- Henri B Wolff
- Centrum Wiskunde and Informatica, Science Park 123, 1098 XG, Amsterdam, The Netherlands
- Departments of Bioengineering, Developmental Biology, and Computational and Systems Biology, University of Pittsburgh, Bioscience Tower 3-5059 3501 Fifth Avenue, Pittsburgh, PA, USA
- Department of Epidemiology and Biostatistics, Decision Modeling Center VUmc, Amsterdam UMC location VUmc, PO Box 7057, 1007 MB, Amsterdam, The Netherlands
| | - Lance A Davidson
- Departments of Bioengineering, Developmental Biology, and Computational and Systems Biology, University of Pittsburgh, Bioscience Tower 3-5059 3501 Fifth Avenue, Pittsburgh, PA, USA.
| | - Roeland M H Merks
- Centrum Wiskunde and Informatica, Science Park 123, 1098 XG, Amsterdam, The Netherlands.
- Mathematical Institute, University Leiden, P.O. Box 9512, 2300 RA, Leiden, The Netherlands.
- Mathematical Institute and Institute of Biology, Leiden University, P.O. Box 9505, 2300 RA, Leiden, The Netherlands.
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8
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Neumann NM, Perrone MC, Veldhuis JH, Huebner RJ, Zhan H, Devreotes PN, Brodland GW, Ewald AJ. Coordination of Receptor Tyrosine Kinase Signaling and Interfacial Tension Dynamics Drives Radial Intercalation and Tube Elongation. Dev Cell 2018; 45:67-82.e6. [PMID: 29634937 DOI: 10.1016/j.devcel.2018.03.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/11/2018] [Accepted: 03/14/2018] [Indexed: 11/16/2022]
Abstract
We sought to understand how cells collectively elongate epithelial tubes. We first used 3D culture and biosensor imaging to demonstrate that epithelial cells enrich Ras activity, phosphatidylinositol (3,4,5)-trisphosphate (PIP3), and F-actin to their leading edges during migration within tissues. PIP3 enrichment coincided with, and could enrich despite inhibition of, F-actin dynamics, revealing a conserved migratory logic compared with single cells. We discovered that migratory cells can intercalate into the basal tissue surface and contribute to tube elongation. We then connected molecular activities to subcellular mechanics using force inference analysis. Migration and transient intercalation required specific and similar anterior-posterior ratios of interfacial tension. Permanent intercalations were distinguished by their capture at the boundary through time-varying tension dynamics. Finally, we integrated our experimental and computational data to generate a finite element model of tube elongation. Our model revealed that intercalation, interfacial tension dynamics, and high basal stress are together sufficient for mammary morphogenesis.
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Affiliation(s)
- Neil M Neumann
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, 855 North Wolfe Street, Rangos 452, Baltimore, MD 21205, USA
| | - Matthew C Perrone
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Jim H Veldhuis
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Robert J Huebner
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, 855 North Wolfe Street, Rangos 452, Baltimore, MD 21205, USA
| | - Huiwang Zhan
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, 855 North Wolfe Street, Rangos 452, Baltimore, MD 21205, USA
| | - Peter N Devreotes
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, 855 North Wolfe Street, Rangos 452, Baltimore, MD 21205, USA
| | - G Wayne Brodland
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, ON N2L 3G1, Canada; Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Andrew J Ewald
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, 855 North Wolfe Street, Rangos 452, Baltimore, MD 21205, USA.
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9
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Mosaffa P, Rodríguez-Ferran A, Muñoz JJ. Hybrid cell-centred/vertex model for multicellular systems with equilibrium-preserving remodelling. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2928. [PMID: 28898926 DOI: 10.1002/cnm.2928] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/06/2017] [Accepted: 09/07/2017] [Indexed: 06/07/2023]
Abstract
We present a hybrid cell-centred/vertex model for mechanically simulating planar cellular monolayers undergoing cell reorganisation. Cell centres are represented by a triangular nodal network, while the cell boundaries are formed by an associated vertex network. The two networks are coupled through a kinematic constraint which we allow to relax progressively. Special attention is paid to the change of cell-cell connectivity due to cell reorganisation or remodelling events. We handle these situations by using a variable resting length and applying an Equilibrium-Preserving Mapping on the new connectivity, which computes a new set of resting lengths that preserve nodal and vertex equilibrium. We illustrate the properties of the model by simulating monolayers subjected to imposed extension and during a wound healing process. The evolution of forces and the Equilibrium-Preserving Mapping are analysed during the remodelling events. As a by-product, the proposed technique enables to recover fully vertex or fully cell-centred models in a seamless manner by modifying a numerical parameter of the model.
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Affiliation(s)
- Payman Mosaffa
- Laboratori de Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
| | - Antonio Rodríguez-Ferran
- Laboratori de Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
| | - José J Muñoz
- Laboratori de Càlcul Numèric (LaCàN), Universitat Politècnica de Catalunya-Barcelona Tech, Barcelona, Spain
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10
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Fletcher AG, Cooper F, Baker RE. Mechanocellular models of epithelial morphogenesis. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0519. [PMID: 28348253 DOI: 10.1098/rstb.2015.0519] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2016] [Indexed: 01/13/2023] Open
Abstract
Embryonic epithelia achieve complex morphogenetic movements, including in-plane reshaping, bending and folding, through the coordinated action and rearrangement of individual cells. Technical advances in molecular and live-imaging studies of epithelial dynamics provide a very real opportunity to understand how cell-level processes facilitate these large-scale tissue rearrangements. However, the large datasets that we are now able to generate require careful interpretation. In combination with experimental approaches, computational modelling allows us to challenge and refine our current understanding of epithelial morphogenesis and to explore experimentally intractable questions. To this end, a variety of cell-based modelling approaches have been developed to describe cell-cell mechanical interactions, ranging from vertex and 'finite-element' models that approximate each cell geometrically by a polygon representing the cell's membrane, to immersed boundary and subcellular element models that allow for more arbitrary cell shapes. Here, we review how these models have been used to provide insights into epithelial morphogenesis and describe how such models could help future efforts to decipher the forces and mechanical and biochemical feedbacks that guide cell and tissue-level behaviour. In addition, we discuss current challenges associated with using computational models of morphogenetic processes in a quantitative and predictive way.This article is part of the themed issue 'Systems morphodynamics: understanding the development of tissue hardware'.
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Affiliation(s)
- Alexander G Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield S3 7RH, UK .,Bateson Centre, University of Sheffield, Sheffield S10 2TN, UK
| | - Fergus Cooper
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK
| | - Ruth E Baker
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK
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11
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Barton DL, Henkes S, Weijer CJ, Sknepnek R. Active Vertex Model for cell-resolution description of epithelial tissue mechanics. PLoS Comput Biol 2017; 13:e1005569. [PMID: 28665934 PMCID: PMC5493290 DOI: 10.1371/journal.pcbi.1005569] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 05/12/2017] [Indexed: 12/31/2022] Open
Abstract
We introduce an Active Vertex Model (AVM) for cell-resolution studies of the mechanics of confluent epithelial tissues consisting of tens of thousands of cells, with a level of detail inaccessible to similar methods. The AVM combines the Vertex Model for confluent epithelial tissues with active matter dynamics. This introduces a natural description of the cell motion and accounts for motion patterns observed on multiple scales. Furthermore, cell contacts are generated dynamically from positions of cell centres. This not only enables efficient numerical implementation, but provides a natural description of the T1 transition events responsible for local tissue rearrangements. The AVM also includes cell alignment, cell-specific mechanical properties, cell growth, division and apoptosis. In addition, the AVM introduces a flexible, dynamically changing boundary of the epithelial sheet allowing for studies of phenomena such as the fingering instability or wound healing. We illustrate these capabilities with a number of case studies.
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Affiliation(s)
- Daniel L. Barton
- Division of Physics, School of Science and Engineering, University of Dundee, Dundee, United Kingdom
- Division of Computational Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Silke Henkes
- Institute of Complex Systems and Mathematical Biology, Department of Physics, University of Aberdeen, Aberdeen, United Kingdom
| | - Cornelis J. Weijer
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Rastko Sknepnek
- Division of Physics, School of Science and Engineering, University of Dundee, Dundee, United Kingdom
- Division of Computational Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
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