1
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Flormann DAD, Kainka L, Montalvo G, Anton C, Rheinlaender J, Thalla D, Vesperini D, Pohland MO, Kaub KH, Schu M, Pezzano F, Ruprecht V, Terriac E, Hawkins RJ, Lautenschläger F. The structure and mechanics of the cell cortex depend on the location and adhesion state. Proc Natl Acad Sci U S A 2024; 121:e2320372121. [PMID: 39042691 PMCID: PMC11295003 DOI: 10.1073/pnas.2320372121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 06/16/2024] [Indexed: 07/25/2024] Open
Abstract
Cells exist in different phenotypes and can transition between them. A phenotype may be characterized by many different aspects. Here, we focus on the example of whether the cell is adhered or suspended and choose particular parameters related to the structure and mechanics of the actin cortex. The cortex is essential to cell mechanics, morphology, and function, such as for adhesion, migration, and division of animal cells. To predict and control cellular functions and prevent malfunctioning, it is necessary to understand the actin cortex. The structure of the cortex governs cell mechanics; however, the relationship between the architecture and mechanics of the cortex is not yet well enough understood to be able to predict one from the other. Therefore, we quantitatively measured structural and mechanical cortex parameters, including cortical thickness, cortex mesh size, actin bundling, and cortex stiffness. These measurements required developing a combination of measurement techniques in scanning electron, expansion, confocal, and atomic force microscopy. We found that the structure and mechanics of the cortex of cells in interphase are different depending on whether the cell is suspended or adhered. We deduced general correlations between structural and mechanical properties and show how these findings can be explained within the framework of semiflexible polymer network theory. We tested the model predictions by perturbing the properties of the actin within the cortex using compounds. Our work provides an important step toward predictions of cell mechanics from cortical structures and suggests how cortex remodeling between different phenotypes impacts the mechanical properties of cells.
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Affiliation(s)
- D. A. D. Flormann
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - L. Kainka
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - G. Montalvo
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - C. Anton
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - J. Rheinlaender
- Faculty of Science, Institute of Applied Physics, University of Tübingen, Tübingen72076, Germany
| | - D. Thalla
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - D. Vesperini
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - M. O. Pohland
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - K. H. Kaub
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
- Department of Biophysical Chemistry, Georg-August-University, Göttingen37077, Germany
| | - M. Schu
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - F. Pezzano
- Center for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona08003, Spain
| | - V. Ruprecht
- Center for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona08003, Spain
- Universitat Pompeu Fabra, Barcelona08002, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona08010, Spain
| | - E. Terriac
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
| | - R. J. Hawkins
- Department of Physics and Astronomy, University of Sheffield, SheffieldS3 7RH, United Kingdom
- African Institute for Mathematical Sciences, Accra20046, Ghana
| | - F. Lautenschläger
- Department of Physics, Saarland University, Saarbrücken 66123, Germany
- Center for Biophysics, Saarland University, Saarbrücken66123, Germany
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2
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Li M, Xing X, Yuan J, Zeng Z. Research progress on the regulatory role of cell membrane surface tension in cell behavior. Heliyon 2024; 10:e29923. [PMID: 38720730 PMCID: PMC11076917 DOI: 10.1016/j.heliyon.2024.e29923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
Cell membrane surface tension has emerged as a pivotal biophysical factor governing cell behavior and fate. This review systematically delineates recent advances in techniques for cell membrane surface tension quantification, mechanosensing mechanisms, and regulatory roles of cell membrane surface tension in modulating major cellular processes. Micropipette aspiration, tether pulling, and newly developed fluorescent probes enable the measurement of cell membrane surface tension with spatiotemporal precision. Cells perceive cell membrane surface tension via conduits including mechanosensitive ion channels, curvature-sensing proteins (e.g. BAR domain proteins), and cortex-membrane attachment proteins (e.g. ERM proteins). Through membrane receptors like integrins, cells convert mechanical cues into biochemical signals. This conversion triggers cytoskeletal remodeling and extracellular matrix interactions in response to environmental changes. Elevated cell membrane surface tension suppresses cell spreading, migration, and endocytosis while facilitating exocytosis. Moreover, reduced cell membrane surface tension promotes embryonic stem cell differentiation and cancer cell invasion, underscoring cell membrane surface tension as a regulator of cell plasticity. Outstanding questions remain regarding cell membrane surface tension regulatory mechanisms and roles in tissue development/disease in vivo. Emerging tools to manipulate cell membrane surface tension with high spatiotemporal control in combination with omics approaches will facilitate the elucidation of cell membrane surface tension-mediated effects on signaling networks across various cell types/states. This will accelerate the development of cell membrane surface tension-based biomarkers and therapeutics for regenerative medicine and cancer. Overall, this review provides critical insights into cell membrane surface tension as a potent orchestrator of cell function, with broader impacts across mechanobiology.
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Affiliation(s)
- Manqing Li
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Xiumei Xing
- School of Public Health, Sun Yat-sen University, Guangzhou, 5180080, China
| | - Jianhui Yuan
- Nanshan District Center for Disease Control and Prevention, Shenzhen, 518054, China
| | - Zhuoying Zeng
- The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen University, Shenzhen, 518035, China
- Chemical Analysis & Physical Testing Institute, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, China
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3
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Nikolić M, Scarcelli G, Tanner K. Multimodal microscale mechanical mapping of cancer cells in complex microenvironments. Biophys J 2022; 121:3586-3599. [PMID: 36059196 PMCID: PMC9617162 DOI: 10.1016/j.bpj.2022.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/05/2022] [Accepted: 09/02/2022] [Indexed: 02/07/2023] Open
Abstract
The mechanical phenotype of the cell is critical for survival following deformations due to confinement and fluid flow. One idea is that cancer cells are plastic and adopt different mechanical phenotypes under different geometries that aid in their survival. Thus, an attractive goal is to disrupt cancer cells' ability to adopt multiple mechanical states. To begin to address this question, we aimed to quantify the diversity of these mechanical states using in vitro biomimetics to mimic in vivo two-dimensional (2D) and 3D extracellular matrix environments. Here, we used two modalities Brillouin microscopy (∼GHz) and broadband frequency (7-15 kHz) optical tweezer microrheology to measure microscale cell mechanics. We measured the response of intracellular mechanics of cancer cells cultured in 2D and 3D environments where we modified substrate stiffness, dimensionality (2D versus 3D), and presence of fibrillar topography. We determined that there was good agreement between two modalities despite the difference in timescale of the two measurements. These findings on cell mechanical phenotype in different environments confirm a correlation between modalities that employ different mechanisms at different temporal scales (Hz-kHz versus GHz). We also determined that observed heterogeneity in cell shape is more closely linked to the cells' mechanical state. Moreover, individual cells in multicellular spheroids exhibit a lower degree of mechanical heterogeneity when compared with single cells cultured in monodisperse 3D cultures. The observed decreased heterogeneity among cells in spheroids suggested that there is mechanical cooperativity between cells that make up a single spheroid.
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Affiliation(s)
- Miloš Nikolić
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland; Maryland Biophysics Program, IPST, University of Maryland, College Park, Maryland
| | - Giuliano Scarcelli
- Maryland Biophysics Program, IPST, University of Maryland, College Park, Maryland; Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Kandice Tanner
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
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4
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Pittman M, Iu E, Li K, Wang M, Chen J, Taneja N, Jo MH, Park S, Jung WH, Liang L, Barman I, Ha T, Gaitanaros S, Liu J, Burnette D, Plotnikov S, Chen Y. Membrane Ruffling is a Mechanosensor of Extracellular Fluid Viscosity. NATURE PHYSICS 2022; 18:1112-1121. [PMID: 37220497 PMCID: PMC10202009 DOI: 10.1038/s41567-022-01676-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 06/17/2022] [Indexed: 05/25/2023]
Abstract
Cell behaviour is affected by the physical forces and mechanical properties of the cells and of their microenvironment. The viscosity of extracellular fluid - a component of the cellular microenvironment - can vary by orders of magnitude, but its effect on cell behaviour remains largely unexplored. Using bio-compatible polymers to increase the viscosity of the culture medium, we characterize how viscosity affects cell behaviour. We find that multiple types of adherent cells respond in an unexpected but similar manner to elevated viscosity. In a highly viscous medium, cells double their spread area, exhibit increased focal adhesion formation and turnover, generate significantly greater traction forces, and migrate nearly two times faster. We observe that when cells are immersed in regular medium, these viscosity-dependent responses require an actively ruffling lamellipodium - a dynamic membrane structure at the front of the cell. We present evidence that cells utilize membrane ruffling to sense changes in extracellular fluid viscosity and to trigger adaptive responses.
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Affiliation(s)
- Matthew Pittman
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Ernest Iu
- Department of Cell & Systems Biology, University of Toronto
| | - Keva Li
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Mingjiu Wang
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Junjie Chen
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Nilay Taneja
- Department of Cell and Developmental Biology, Vanderbilt University
| | | | - Seungman Park
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Wei-Hung Jung
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
| | - Le Liang
- Department of Mechanical Engineering, Johns Hopkins University
| | - Ishan Barman
- Department of Mechanical Engineering, Johns Hopkins University
| | - Taekjip Ha
- Department of Biophysics, Johns Hopkins University
| | | | - Jian Liu
- Department of Cell Biology, Johns Hopkins University School of Medicine
| | - Dylan Burnette
- Department of Cell and Developmental Biology, Vanderbilt University
| | | | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University
- Institute for NanoBioTechnology, Johns Hopkins University
- Center for Cell Dynamics, Johns Hopkins University
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5
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Epithelial cells sacrifice excess area to preserve fluidity in response to external mechanical stress. Commun Biol 2022; 5:855. [PMID: 35995827 PMCID: PMC9395404 DOI: 10.1038/s42003-022-03809-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/04/2022] [Indexed: 11/24/2022] Open
Abstract
Viscoelastic properties of epithelial cells subject to shape changes were monitored by indentation-retraction/relaxation experiments. MDCK II cells cultured on extensible polydimethylsiloxane substrates were laterally stretched and, in response, displayed increased cortex contractility and loss of excess surface area. Thereby, the cells preserve their fluidity but inevitably become stiffer. We found similar behavior in demixed cell monolayers of ZO-1/2 double knock down (dKD) cells, cells exposed to different temperatures and after removal of cholesterol from the plasma membrane. Conversely, the mechanical response of single cells adhered onto differently sized patches displays no visible rheological change. Sacrificing excess surface area allows the cells to respond to mechanical challenges without losing their ability to flow. They gain a new degree of freedom that permits resolving the interdependence of fluidity β on stiffness \documentclass[12pt]{minimal}
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\begin{document}$${K}_{{{{{{{{\rm{A}}}}}}}}}^{0}$$\end{document}KA0. We also propose a model that permits to tell apart contributions from excess membrane area and excess cell surface area. The viscoelastic properties of cells subjected to external strain are assessed, showing that cells become stiffer but preserve fluidity by sacrificing their excess surface area.
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6
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Harmand N, Dervaux J, Poulard C, Hénon S. Thickness of epithelia on wavy substrates: measurements and continuous models. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:53. [PMID: 35661937 DOI: 10.1140/epje/s10189-022-00206-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 05/09/2022] [Indexed: 06/15/2023]
Abstract
We measured the thickness of MDCK epithelia grown on substrates with a sinusoidal profile. We show that while at long wavelength the profile of the epithelium follows that of the substrate, at short wavelengths cells are thicker in valleys than on ridges. This is reminiscent of the so-called «healing length in the case of a thin liquid film wetting a rough solid substrate. We explore the ability of continuum mechanics models to account for these observations. Modeling the epithelium as a thin liquid film, with surface tension, does not fully account for the measurements. Neither does modeling the epithelium as a thin incompressible elastic film. On the contrary, the addition of an apical active stress gives satisfactory agreement with measurements, with one fitting parameter, the ratio between the active stress and the elastic modulus.
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Affiliation(s)
- Nicolas Harmand
- Université Paris Cité, CNRS, Matiére et Systémes Complexes, UMR 7057,, Paris, France
| | - Julien Dervaux
- Université Paris Cité, CNRS, Matiére et Systémes Complexes, UMR 7057,, Paris, France
| | - Christophe Poulard
- Laboratoire de Physique des Solides, CNRS, UMR 8502, Université Paris-Saclay, Orsay, France
| | - Sylvie Hénon
- Université Paris Cité, CNRS, Matiére et Systémes Complexes, UMR 7057,, Paris, France.
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7
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Venkova L, Vishen AS, Lembo S, Srivastava N, Duchamp B, Ruppel A, Williart A, Vassilopoulos S, Deslys A, Garcia Arcos JM, Diz-Muñoz A, Balland M, Joanny JF, Cuvelier D, Sens P, Piel M. A mechano-osmotic feedback couples cell volume to the rate of cell deformation. eLife 2022; 11:72381. [PMID: 35416768 PMCID: PMC9090331 DOI: 10.7554/elife.72381] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 04/08/2022] [Indexed: 11/13/2022] Open
Abstract
Mechanics has been a central focus of physical biology in the past decade. In comparison, how cells manage their size is less understood. Here we show that a parameter central to both the physics and the physiology of the cell, its volume, depends on a mechano-osmotic coupling. We found that cells change their volume depending on the rate at which they change shape, when they spontaneously spread are externally deformed. Cells undergo slow deformation at constant volume, while fast deformation leads to volume loss. We propose a mechano-sensitive pump and leak model to explain this phenomenon. Our model and experiments suggest that volume modulation depends on the state of the actin cortex and the coupling of ion fluxes to membrane tension. This mechano-osmotic coupling defines a membrane tension homeostasis module constantly at work in cells, causing volume fluctuations associated with fast cell shape changes, with potential consequences on cellular physiology.
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Affiliation(s)
- Larisa Venkova
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | - Amit Singh Vishen
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | - Sergio Lembo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Nishit Srivastava
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | - Baptiste Duchamp
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | - Artur Ruppel
- Laboratoire Interdisciplinaire de Physique, Grenoble, France
| | - Alice Williart
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | | | - Alexandre Deslys
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | | | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Martial Balland
- Laboratoire Interdisciplinaire de Physique, Grenoble, France
| | | | - Damien Cuvelier
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
| | - Pierre Sens
- Laboratoire Physico Chimie Curie, Institut Curie, CNRS UMR168, Paris, France
| | - Matthieu Piel
- PSL Research University, Institut Curie, CNRS, UMR 144, Paris, France
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8
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Papadakis L, Karatsis E, Michalakis K, Tsouknidas A. Cellular Biomechanics: Fluid-Structure Interaction Or Structural Simulation? J Biomech 2022; 136:111084. [DOI: 10.1016/j.jbiomech.2022.111084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 04/01/2022] [Accepted: 04/04/2022] [Indexed: 11/24/2022]
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9
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Nietmann P, Bodenschatz JE, Cordes AM, Gottwald J, Rother-Nöding H, Oswald T, Janshoff A. Epithelial cells fluidize upon adhesion but display mechanical homeostasis in the adherent state. Biophys J 2022; 121:361-373. [PMID: 34998827 PMCID: PMC8822618 DOI: 10.1016/j.bpj.2021.12.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/02/2021] [Accepted: 12/28/2021] [Indexed: 02/03/2023] Open
Abstract
Atomic force microscopy is used to study the viscoelastic properties of epithelial cells in three different states. Force relaxation data are acquired from cells in suspension, adhered but single cells, and polarized cells in a confluent monolayer using different indenter geometries comprising flat bars, pyramidal cones, and spheres. We found that the fluidity of cells increased substantially from the suspended to the adherent state. Along this line, the prestress of suspended cells generated by cortical contractility is also greater than that of cells adhering to a surface. Polarized cells that are part of a confluent monolayer form an apical cap that is soft and fluid enough to respond rapidly to mechanical challenges from wounding, changes in the extracellular matrix, osmotic stress, and external deformation. In contrast to adherent cells, cells in the suspended state show a pronounced dependence of fluidity on the external areal strain. With increasing areal strain, the suspended cells become softer and more fluid. We interpret the results in terms of cytoskeletal remodeling that softens cells in the adherent state to facilitate adhesion and spreading by relieving internal active stress. However, once the cells spread on the surface they maintain their mechanical phenotype displaying viscoelastic homeostasis.
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Affiliation(s)
- Peter Nietmann
- Georg-August Universität, Institute for Physical Chemistry, Göttingen, Germany
| | | | - Andrea M. Cordes
- Georg-August Universität, Institute for Physical Chemistry, Göttingen, Germany
| | - Jannis Gottwald
- Georg-August Universität, Institute for Physical Chemistry, Göttingen, Germany
| | - Helen Rother-Nöding
- Georg-August Universität, Institute for Physical Chemistry, Göttingen, Germany
| | - Tabea Oswald
- Georg-August Universität, Institute for Organic and Biomolecular Chemistry, Göttingen, Germany
| | - Andreas Janshoff
- Georg-August Universität, Institute for Physical Chemistry, Göttingen, Germany,Corresponding author
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10
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Barbera S, Lugano R, Pedalina A, Mongiat M, Santucci A, Tosi GM, Dimberg A, Galvagni F, Orlandini M. The C-type lectin CD93 controls endothelial cell migration via activation of the Rho family of small GTPases. Matrix Biol 2021; 99:1-17. [PMID: 34062268 DOI: 10.1016/j.matbio.2021.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 02/07/2023]
Abstract
Endothelial cell migration is essential to angiogenesis, enabling the outgrowth of new blood vessels both in physiological and pathological contexts. Migration requires the activation of several signaling pathways, the elucidation of which expands the opportunity to develop new drugs to be used in antiangiogenic therapy. In the proliferating endothelium, the interaction between the transmembrane glycoprotein CD93 and the extracellular matrix activates signaling pathways that regulate cell adhesion, migration, and vascular maturation. Here we identify a pathway, comprising CD93, the adaptor proteins Cbl and Crk, and the small GTPases Rac1, Cdc42, and RhoA, which we propose acts as a regulator of cytoskeletal movements responsible for endothelial cell migration. In this framework, phosphorylation of Cbl on tyrosine 774 leads to the interaction with Crk, which acts as a downstream integrator in the CD93-mediated signaling regulating cell polarity and migration. Moreover, confocal microscopy analyses of GTPase biosensors show that CD93 drives coordinated activation of Rho-proteins at the cell edge of migratory endothelial cells. In conclusion, together with the demonstration of the key contribution of CD93 to the migratory process in living cells, these findings suggest that the signaling triggered by CD93 converges to the activation and modulation of the Rho GTPase signaling pathways regulating cell dynamics.
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Affiliation(s)
- Stefano Barbera
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Italy; Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
| | - Roberta Lugano
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
| | - Alessia Pedalina
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Italy
| | - Maurizio Mongiat
- Department of Research and Diagnosis, Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, Italy
| | - Annalisa Santucci
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Italy
| | - Gian Marco Tosi
- Department of Medicine, Surgery and Neuroscience, Ophthalmology Unit, University of Siena, Italy
| | - Anna Dimberg
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
| | - Federico Galvagni
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Italy
| | - Maurizio Orlandini
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Italy.
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11
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Naqvi SM, McNamara LM. Stem Cell Mechanobiology and the Role of Biomaterials in Governing Mechanotransduction and Matrix Production for Tissue Regeneration. Front Bioeng Biotechnol 2020; 8:597661. [PMID: 33381498 PMCID: PMC7767888 DOI: 10.3389/fbioe.2020.597661] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Mechanobiology has underpinned many scientific advances in understanding how biophysical and biomechanical cues regulate cell behavior by identifying mechanosensitive proteins and specific signaling pathways within the cell that govern the production of proteins necessary for cell-based tissue regeneration. It is now evident that biophysical and biomechanical stimuli are as crucial for regulating stem cell behavior as biochemical stimuli. Despite this, the influence of the biophysical and biomechanical environment presented by biomaterials is less widely accounted for in stem cell-based tissue regeneration studies. This Review focuses on key studies in the field of stem cell mechanobiology, which have uncovered how matrix properties of biomaterial substrates and 3D scaffolds regulate stem cell migration, self-renewal, proliferation and differentiation, and activation of specific biological responses. First, we provide a primer of stem cell biology and mechanobiology in isolation. This is followed by a critical review of key experimental and computational studies, which have unveiled critical information regarding the importance of the biophysical and biomechanical cues for stem cell biology. This review aims to provide an informed understanding of the intrinsic role that physical and mechanical stimulation play in regulating stem cell behavior so that researchers may design strategies that recapitulate the critical cues and develop effective regenerative medicine approaches.
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Affiliation(s)
- S M Naqvi
- Mechanobiology and Medical Device Research Group, Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - L M McNamara
- Mechanobiology and Medical Device Research Group, Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
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12
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Sitarska E, Diz-Muñoz A. Pay attention to membrane tension: Mechanobiology of the cell surface. Curr Opin Cell Biol 2020; 66:11-18. [PMID: 32416466 PMCID: PMC7594640 DOI: 10.1016/j.ceb.2020.04.001] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 02/09/2023]
Abstract
The cell surface is a mechanobiological unit that encompasses the plasma membrane, its interacting proteins, and the complex underlying cytoskeleton. Recently, attention has been directed to the mechanics of the plasma membrane, and in particular membrane tension, which has been linked to diverse cellular processes such as cell migration and membrane trafficking. However, how tension across the plasma membrane is regulated and propagated is still not completely understood. Here, we review recent efforts to study the interplay between membrane tension and the cytoskeletal machinery and how they control cell form and function. We focus on factors that have been proposed to affect the propagation of membrane tension and as such could determine whether it can act as a global or local regulator of cell behavior. Finally, we discuss the limitations of the available tool kit as new approaches that reveal its dynamics in cells are needed to decipher how membrane tension regulates diverse cellular processes.
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Affiliation(s)
- Ewa Sitarska
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117, Heidelberg, Germany
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117, Heidelberg, Germany.
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13
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Witt H, Vache M, Cordes A, Janshoff A. Detachment of giant liposomes - coupling of receptor mobility and membrane shape. SOFT MATTER 2020; 16:6424-6433. [PMID: 32588015 DOI: 10.1039/d0sm00863j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cellular adhesion is an intricate physical process controlled by ligand-receptor affinity, density, mobility, and external forces transmitted through the elastic properties of the cell. As a model for cellular adhesion we study the detachment of cell-sized liposomes and membrane-coated silica beads from supported bilayers using atomic force microscopy. Adhesion between the two surfaces is mediated by the interaction between the adhesive lipid anchored saccharides lactosylceramide and the ganglioside GM3. We found that force-distance curves of liposome detachment have a very peculiar, partially concave shape, reminiscent of the nonlinear extension of polymers. By contrast, detachment of membrane coated beads led to force-distance curves similar to the detachment of living cells. Theoretical modelling of the enforced detachment suggests that the non-convex force curve shape arises from the mobility of ligands provoking a switch of shapes from spherical to unduloidal during detachment.
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Affiliation(s)
- Hannes Witt
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg, 37077 Göttingen, Germany
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14
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Soares J, Araujo GRDS, Santana C, Matias D, Moura-Neto V, Farina M, Frases S, Viana NB, Romão L, Nussenzveig HM, Pontes B. Membrane Elastic Properties During Neural Precursor Cell Differentiation. Cells 2020; 9:E1323. [PMID: 32466390 PMCID: PMC7349228 DOI: 10.3390/cells9061323] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/15/2020] [Accepted: 05/17/2020] [Indexed: 02/08/2023] Open
Abstract
Neural precursor cells differentiate into several cell types that display distinct functions. However, little is known about how cell surface mechanics vary during the differentiation process. Here, by precisely measuring membrane tension and bending modulus, we map their variations and correlate them with changes in neural precursor cell morphology along their distinct differentiation fates. Both cells maintained in culture as neural precursors as well as those plated in neurobasal medium reveal a decrease in membrane tension over the first hours of culture followed by stabilization, with no change in bending modulus. During astrocyte differentiation, membrane tension initially decreases and then increases after 72 h, accompanied by consolidation of glial fibrillary acidic protein expression and striking actin reorganization, while bending modulus increases following observed alterations. For oligodendrocytes, the changes in membrane tension are less abrupt over the first hours, but their values subsequently decrease, correlating with a shift from oligodendrocyte marker O4 to myelin basic protein expressions and a remarkable actin reorganization, while bending modulus remains constant. Oligodendrocytes at later differentiation stages show membrane vesicles with similar membrane tension but higher bending modulus as compared to the cell surface. Altogether, our results display an entire spectrum of how membrane elastic properties are varying, thus contributing to a better understanding of neural differentiation from a mechanobiological perspective.
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Affiliation(s)
- Juliana Soares
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil;
| | - Glauber R. de S. Araujo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (G.R.d.S.A.); (S.F.)
| | - Cintia Santana
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
| | - Diana Matias
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria de Estado de Saúde, Rio de Janeiro, RJ 20231-092, Brazil
| | - Vivaldo Moura-Neto
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
- Instituto Estadual do Cérebro Paulo Niemeyer, Secretaria de Estado de Saúde, Rio de Janeiro, RJ 20231-092, Brazil
| | - Marcos Farina
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
| | - Susana Frases
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (G.R.d.S.A.); (S.F.)
| | - Nathan B. Viana
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil;
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-942, Brazil
| | - Luciana Romão
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
| | - H. Moysés Nussenzveig
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil;
- Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-942, Brazil
| | - Bruno Pontes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; (J.S.); (C.S.); (D.M.); (V.M.-N.); (M.F.); (L.R.)
- Centro Nacional de Biologia Estrutural e Bioimagem (CENABIO), Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil;
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15
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Lv JQ, Chen PC, Góźdź WT, Li B. Mechanical adaptions of collective cells nearby free tissue boundaries. J Biomech 2020; 104:109763. [PMID: 32224050 DOI: 10.1016/j.jbiomech.2020.109763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 11/19/2022]
Abstract
Mechanical adaptions of cells, including stiffness variation, cytoskeleton remodeling, motion coordination, and shape changing, are essential for tissue morphogenesis, wound healing, and malignant progression. In this paper, we take confluent monolayers of Madin-Darby canine kidney (MDCK) and mouse myoblast (C2C12) cells as model systems to probe how cells collectively adapt their mechanical features in response to a free tissue boundary. We show that the free boundary not only can trigger unjamming transition but also induces cell fluidization nearby the boundary. The Young's moduli of cells near the boundary are found to be much lower than those of interior cells. We demonstrate that the stiffness of cells in monolayers with a free tissue boundary exhibits negative dependence on the projected cell area, in contrast to previous studies where cells were found to stiffen as cellular area increases in a confluent MDCK monolayer without boundary. In addition, the free tissue boundary may activate cell remodeling, rendering volume enlargement and cell-specified cytoskeleton organization. Our study emphasizes the important role of geometrical boundary in regulating biomechanical properties of cell aggregates.
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Affiliation(s)
- Jian-Qing Lv
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Peng-Cheng Chen
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Wojciech T Góźdź
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Bo Li
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
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16
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Guo J, Guo C, Xu L, Jia J, Jia R. Enhanced transfection efficiency by using a novel semi-attachment method in cell line and primary cells. Anal Biochem 2019; 587:113465. [PMID: 31585099 DOI: 10.1016/j.ab.2019.113465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 09/24/2019] [Accepted: 09/27/2019] [Indexed: 10/25/2022]
Abstract
DNA transfection in cells is a key technique in biological studies. Cationic liposomes can form nanoparticle complexes with DNA and are widely used for gene delivery in mammalian cells. However, the major drawback of cationic liposomes is their low transfection efficiency in hard-to-transfect cells, such as primary cultured cells. In this study, we established a novel semi-attachment transfection method that showed remarkably improved transfection efficiency compared with traditional forward transfection method.
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Affiliation(s)
- Jihua Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China; Department of Endodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
| | - Chen Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
| | - Lingfeng Xu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
| | - Jun Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
| | - Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, PR China.
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17
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Stiffness of MDCK II Cells Depends on Confluency and Cell Size. Biophys J 2019; 116:2204-2211. [PMID: 31126583 DOI: 10.1016/j.bpj.2019.04.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/25/2019] [Accepted: 04/22/2019] [Indexed: 12/26/2022] Open
Abstract
Mechanical phenotyping of adherent cells has become a serious tool in cell biology to understand how cells respond to their environment and eventually to identify disease patterns such as the malignancy of cancer cells. In the steady state, homeostasis is of pivotal importance, and cells strive to maintain their internal stresses even in challenging environments and in response to external chemical and mechanical stimuli. However, a major problem exists in determining mechanical properties because many techniques, such as atomic force microscopy, that assess these properties of adherent cells locally can only address a limited number of cells and provide elastic moduli that vary substantially from cell to cell. The origin of this spread in stiffness values is largely unknown and might limit the significance of measurements. Possible reasons for the disparity are variations in cell shape and size, as well as biological reasons such as the cell cycle or polarization state of the cell. Here, we show that stiffness of adherent epithelial cells rises with increasing projected apical cell area in a nonlinear fashion. This size stiffening not only occurs as a consequence of varying cell-seeding densities, it can also be observed within a small area of a particular cell culture. Experiments with single adherent cells attached to defined areas via microcontact printing show that size stiffening is limited to cells of a confluent monolayer. This leads to the conclusion that cells possibly regulate their size distribution through cortical stress, which is enhanced in larger cells and reduced in smaller cells.
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18
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Hong S, Sunwoo JH, Kim JS, Tchah H, Hwang C. Conjugation of carboxymethyl cellulose and dopamine for cell sheet harvesting. Biomater Sci 2019; 7:139-148. [DOI: 10.1039/c8bm00971f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This manuscript focuses on the cell sheet preparation methodology with the conjugation of carboxymethylcellulose (CMC) and dopamine (DA).
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Affiliation(s)
- Soyoung Hong
- Biomedical Engineering Research Center
- Asan Institute for Life Sciences
- Asan Medical Center
- Seoul 05505
- Republic of Korea
| | - Jeong Hey Sunwoo
- Biomedical Engineering Research Center
- Asan Institute for Life Sciences
- Asan Medical Center
- Seoul 05505
- Republic of Korea
| | - Ji Seon Kim
- Biomedical Engineering Research Center
- Asan Institute for Life Sciences
- Asan Medical Center
- Seoul 05505
- Republic of Korea
| | - Hungwon Tchah
- Department of Convergence Medicine
- University of Ulsan College of Medicine & Asan Institute for Life Sciences
- Asan Medical Center
- Seoul 05505
- Republic of Korea
| | - Changmo Hwang
- Biomedical Engineering Research Center
- Asan Institute for Life Sciences
- Asan Medical Center
- Seoul 05505
- Republic of Korea
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19
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Golan M, Pribyl J, Pesl M, Jelinkova S, Acimovic I, Jaros J, Rotrekl V, Falk M, Sefc L, Skladal P, Kratochvilova I. Cryopreserved Cells Regeneration Monitored by Atomic Force Microscopy and Correlated With State of Cytoskeleton and Nuclear Membrane. IEEE Trans Nanobioscience 2018; 17:485-497. [PMID: 30307873 DOI: 10.1109/tnb.2018.2873425] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Atomic force microscopy (AFM) helps to describe and explain the mechanobiological properties of living cells on the nanoscale level under physiological conditions. The stiffness of cells is an important parameter reflecting cell physiology. Here, we have provided the first study of the stiffness of cryopreserved cells during post-thawing regeneration using AFM combined with confocal fluorescence microscopy. We demonstrated that the nonfrozen cell stiffness decreased proportionally to the cryoprotectant concentration in the medium. AFM allowed us to map cell surface reconstitution in real time after a freeze/thaw cycle and to monitor the regeneration processes at different depths of the cell and even different parts of the cell surface (nucleus and edge). Fluorescence microscopy showed that the cytoskeleton in fibroblasts, though damaged by the freeze/thaw cycle, is reconstructed after long-term plating. Confocal microscopy confirmed that structural changes affect the nuclear envelopes in cryopreserved cells. AFM nanoindentation analysis could be used as a noninvasive method to identify cells that have regenerated their surface mechanical properties with the proper dynamics and to a sufficient degree. This identification can be important particularly in the field of in vitro fertilization and in future cell-based regeneration strategies.
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20
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Ayee MA, Levitan I. Membrane Stiffening in Osmotic Swelling: Analysis of Membrane Tension and Elastic Modulus. CURRENT TOPICS IN MEMBRANES 2018; 81:97-123. [PMID: 30243442 PMCID: PMC6588289 DOI: 10.1016/bs.ctm.2018.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects of osmotic swelling on key cellular biomechanical properties are explored in this chapter. We present the governing equations and theoretical backgrounds of the models employed to estimate cell membrane tension and elastic moduli from experimental methods, and provide a summary of the prevailing experimental approaches used to obtain these biomechanical parameters. A detailed analysis of the current evidence of the effects of osmotic swelling on membrane tension and elastic moduli is provided. Briefly, due to the buffering effect of unfolding membrane reservoirs, mild hypotonic swelling does not change membrane tension or the adhesion of the membrane to the underlying cytoskeleton. Conversely, osmotic swelling causes the cell membrane envelope to stiffen, measured as an increase in the membrane elastic modulus.
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Affiliation(s)
| | - Irena Levitan
- University of Illinois at Chicago, Chicago, IL, United States
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21
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Nanoscale characterization of dynamic cellular viscoelasticity by atomic force microscopy with varying measurement parameters. J Mech Behav Biomed Mater 2018; 82:193-201. [DOI: 10.1016/j.jmbbm.2018.03.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/14/2018] [Accepted: 03/26/2018] [Indexed: 12/23/2022]
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22
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Nehls S, Janshoff A. Elastic Properties of Pore-Spanning Apical Cell Membranes Derived from MDCK II Cells. Biophys J 2017; 113:1822-1830. [PMID: 29045876 DOI: 10.1016/j.bpj.2017.08.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/04/2017] [Accepted: 08/10/2017] [Indexed: 11/25/2022] Open
Abstract
The mechanical response of adherent, polarized cells to indentation is frequently attributed to the presence of an endogenous actin cortex attached to the inner leaflet of the plasma membrane. Here, we scrutinized the elastic properties of apical membranes separated from living cells and attached to a porous mesh in the absence of intracellular factors originating from the cytosol, organelles, the substrate, neighbors, and the nucleus. We found that a tension-based model describes the data very well providing essentially the prestress of the shell generated by adhesion of the apical membrane patches to the pore rim and the apparent area compressibility modulus, an intrinsic elastic modulus modulated by the surface excess stored in membrane reservoirs. Removal of membrane-associated proteins by proteases decreases the area compressibility modulus, whereas fixation and cross-linking of proteins with glutaraldehyde increases it.
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Affiliation(s)
- Stefan Nehls
- Georg-August-Universität Göttingen, Institute of Physical Chemistry, Göttingen, Germany
| | - Andreas Janshoff
- Georg-August-Universität Göttingen, Institute of Physical Chemistry, Göttingen, Germany.
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23
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Gullekson C, Cojoc G, Schürmann M, Guck J, Pelling A. Mechanical mismatch between Ras transformed and untransformed epithelial cells. SOFT MATTER 2017; 13:8483-8491. [PMID: 29091102 DOI: 10.1039/c7sm01396e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The organization of the actin cytoskeleton plays a key role in regulating cell mechanics. It is fundamentally altered during transformation, affecting how cells interact with their environment. We investigated mechanical properties of cells expressing constitutively active, oncogenic Ras (RasV12) in adherent and suspended states. To do this, we utilized atomic force microscopy and a microfluidic optical stretcher. We found that adherent cells stiffen and suspended cells soften with the expression of constitutively active Ras. The effect on adherent cells was reversed when contractility was inhibited with the ROCK inhibitor Y-27632, resulting in softer RasV12 cells. Our findings suggest that increased ROCK activity as a result of Ras has opposite effects on suspended and adhered cells. Our results also establish the importance of the activation of ROCK by Ras and its effect on cell mechanics.
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Affiliation(s)
- Corinne Gullekson
- Centre for Interdisciplinary NanoPhysics, Department of Physics, University of Ottawa, 598 King Edward, Ottawa, ON, K1N5N5 Canada.
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24
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Kliesch TT, Dietz J, Turco L, Halder P, Polo E, Tarantola M, Jahn R, Janshoff A. Membrane tension increases fusion efficiency of model membranes in the presence of SNAREs. Sci Rep 2017; 7:12070. [PMID: 28935937 PMCID: PMC5608890 DOI: 10.1038/s41598-017-12348-w] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 09/05/2017] [Indexed: 11/24/2022] Open
Abstract
The large gap in time scales between membrane fusion occurring in biological systems during neurotransmitter release and fusion observed between model membranes has provoked speculations over a large number of possible factors that might explain this discrepancy. One possible reason is an elevated lateral membrane tension present in the presynaptic membrane. We investigated the tension-dependency of fusion using model membranes equipped with a minimal fusion machinery consisting of syntaxin 1, synaptobrevin and SNAP 25. Two different strategies were realized; one based on supported bilayers and the other one employing sessile giant liposomes. In the first approach, isolated patches of planar bilayers derived from giant unilamellar vesicles containing syntaxin 1 and preassembled SNAP 25 (ΔN-complex) were deposited on a dilatable PDMS sheet. In a second approach, lateral membrane tension was controlled through the adhesion of intact giant unilamellar vesicles on a functionalized surface. In both approaches fusion efficiency increases considerably with lateral tension and we identified a threshold tension of 3.4 mN m−1, at which the number of fusion events is increased substantially.
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Affiliation(s)
| | - Jörn Dietz
- Institute of Physical Chemistry, Georg-August-University, Göttingen, 37077, Germany
| | - Laura Turco
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, 37077, Germany
| | - Partho Halder
- Max-Planck-Institute for Biophysical Chemistry, Göttingen, 37077, Germany
| | - Elena Polo
- Institute of Physical Chemistry, Georg-August-University, Göttingen, 37077, Germany
| | - Marco Tarantola
- Max-Planck-Institute for Dynamics and Self-Organization, Göttingen, 37077, Germany
| | - Reinhard Jahn
- Max-Planck-Institute for Biophysical Chemistry, Göttingen, 37077, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, Georg-August-University, Göttingen, 37077, Germany.
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25
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Cadherin-11 promotes neural crest cell spreading by reducing intracellular tension-Mapping adhesion and mechanics in neural crest explants by atomic force microscopy. Semin Cell Dev Biol 2017; 73:95-106. [PMID: 28919310 DOI: 10.1016/j.semcdb.2017.08.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 11/21/2022]
Abstract
During development cranial neural crest cells (NCCs) display a striking transition from collective to single-cell migration, but the mechanisms enabling individual NCCs to separate from the neural crest tissue are still incompletely understood. In this study we have employed atomic force microscopy (AFM) to investigate potential adhesive and mechanical changes associated with the dissociation of individual cells from cohesive Xenopus NCC explants at early stages of migration. AFM-based single-cell force spectroscopy (SCFS) revealed a uniform distribution of cell-cell adhesion forces within NCC explants, including semi-detached leader cells in the process of delaminating from the explant edge. This suggested that dissociation from the cell sheet may not require prior weakening of cell-cell contacts. However, mapping NCC sheet elasticity by AFM microbead indentation demonstrated strongly reduced cell stiffness in semi-detached leader cells compared to neighbouring cells in the NCC sheet periphery. Reduced leader cell stiffness coincided with enhanced cell spreading and high substrate traction, indicating a possible mechano-regulation of leader cell delamination. In support, AFM elasticity measurements of individual NCCs in optical side view mode demonstrated that reducing cell tension by inhibiting actomyosin contractility induces rapid spreading, possibly maximizing cell-substrate interactions as a result. Depletion of cadherin-11, a classical cadherin with an essential role in NCC migration and substrate adhesion, prevented the tension reduction necessary for NCC spreading, both in individual cells and at the edge of explanted sheets. In contrast, overexpression of cadherin-11 accelerated spreading of both individual cells and delaminating leader cells. As cadherin-11 expression increases strongly during NCC migration, this suggests an important role of cadherin-11 in regulating NCC elasticity and spreading at later stages of NCC migration. We therefore propose a model in which high tension at the NCC sheet periphery prevents premature NCC spreading and delamination during early stages of migration, while a cadherin-11-dependent local decrease in cell tension promotes leader cell spreading and delamination at later stages of migration.
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26
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Yeh YH(J, Lin CM, Chen TT. Human IGF-I Eb-peptide induces cell attachment and lamellipodia outspread of metastatic breast carcinoma cells (MDA-MB-231). Exp Cell Res 2017; 358:199-208. [DOI: 10.1016/j.yexcr.2017.06.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/18/2017] [Accepted: 06/22/2017] [Indexed: 11/29/2022]
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27
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Brückner BR, Nöding H, Janshoff A. Viscoelastic Properties of Confluent MDCK II Cells Obtained from Force Cycle Experiments. Biophys J 2017; 112:724-735. [PMID: 28256232 PMCID: PMC5340129 DOI: 10.1016/j.bpj.2016.12.032] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/01/2016] [Accepted: 12/15/2016] [Indexed: 01/04/2023] Open
Abstract
The local mechanical properties of cells are frequently probed by force indentation experiments carried out with an atomic force microscope. Application of common contact models provides a single parameter, the Young’s modulus, to describe the elastic properties of cells. The viscoelastic response of cells, however, is generally measured in separate microrheological experiments that provide complex shear moduli as a function of time or frequency. Here, we present a straightforward way to obtain rheological properties of cells from regular force distance curves collected in typical force indentation measurements. The method allows us to record the stress-strain relationship as well as changes in the weak power law of the viscoelastic moduli. We derive an analytical function based on the elastic-viscoelastic correspondence principle applied to Hertzian contact mechanics to model both indentation and retraction curves. Rheological properties are described by standard viscoelastic models and the paradigmatic weak power law found to interpret the viscoelastic properties of living cells best. We compare our method with atomic force microscopy-based active oscillatory microrheology and show that the method to determine the power law coefficient is robust against drift and largely independent of the indentation depth and indenter geometry. Cells were subject to Cytochalasin D treatment to provoke a drastic change in the power law coefficient and to demonstrate the feasibility of the approach to capture rheological changes extremely fast and precisely. The method is easily adaptable to different indenter geometries and acquires viscoelastic data with high spatiotemporal resolution.
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Affiliation(s)
| | - Helen Nöding
- Georg-August-Universität Göttingen, Institute of Physical Chemistry, Göttingen, Germany
| | - Andreas Janshoff
- Georg-August-Universität Göttingen, Institute of Physical Chemistry, Göttingen, Germany.
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28
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Cartagena-Rivera AX, Logue JS, Waterman CM, Chadwick RS. Actomyosin Cortical Mechanical Properties in Nonadherent Cells Determined by Atomic Force Microscopy. Biophys J 2017; 110:2528-2539. [PMID: 27276270 PMCID: PMC4906360 DOI: 10.1016/j.bpj.2016.04.034] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/29/2016] [Accepted: 04/25/2016] [Indexed: 12/18/2022] Open
Abstract
The organization of filamentous actin and myosin II molecular motor contractility is known to modify the mechanical properties of the cell cortical actomyosin cytoskeleton. Here we describe a novel method, to our knowledge, for using force spectroscopy approach curves with tipless cantilevers to determine the actomyosin cortical tension, elastic modulus, and intracellular pressure of nonadherent cells. We validated the method by measuring the surface tension of water in oil microdrops deposited on a glass surface. We extracted an average tension of T ∼ 20.25 nN/μm, which agrees with macroscopic experimental methods. We then measured cortical mechanical properties in nonadherent human foreskin fibroblasts and THP-1 human monocytes before and after pharmacological perturbations of actomyosin activity. Our results show that myosin II activity and actin polymerization increase cortex tension and intracellular pressure, whereas branched actin networks decreased them. Interestingly, myosin II activity stiffens the cortex and branched actin networks soften it, but actin polymerization has no effect on cortex stiffness. Our method is capable of detecting changes in cell mechanical properties in response to perturbations of the cytoskeleton, allowing characterization with physically relevant parameters. Altogether, this simple method should be of broad application for deciphering the molecular regulation of cell cortical mechanical properties.
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Affiliation(s)
- Alexander X Cartagena-Rivera
- Laboratory of Cellular Biology, Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Jeremy S Logue
- Laboratory of Cellular Biology, Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland; Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Clare M Waterman
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Richard S Chadwick
- Laboratory of Cellular Biology, Section on Auditory Mechanics, National Institute on Deafness and Other Communication Disorders, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
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Elkhatib N, Bresteau E, Baschieri F, Rioja AL, van Niel G, Vassilopoulos S, Montagnac G. Tubular clathrin/AP-2 lattices pinch collagen fibers to support 3D cell migration. Science 2017; 356:356/6343/eaal4713. [DOI: 10.1126/science.aal4713] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 04/10/2017] [Accepted: 05/11/2017] [Indexed: 12/11/2022]
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Li M, Dang D, Liu L, Xi N, Wang Y. Atomic Force Microscopy in Characterizing Cell Mechanics for Biomedical Applications: A Review. IEEE Trans Nanobioscience 2017; 16:523-540. [PMID: 28613180 DOI: 10.1109/tnb.2017.2714462] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cell mechanics is a novel label-free biomarker for indicating cell states and pathological changes. The advent of atomic force microscopy (AFM) provides a powerful tool for quantifying the mechanical properties of single living cells in aqueous conditions. The wide use of AFM in characterizing cell mechanics in the past two decades has yielded remarkable novel insights in understanding the development and progression of certain diseases, such as cancer, showing the huge potential of cell mechanics for practical applications in the field of biomedicine. In this paper, we reviewed the utilization of AFM to characterize cell mechanics. First, the principle and method of AFM single-cell mechanical analysis was presented, along with the mechanical responses of cells to representative external stimuli measured by AFM. Next, the unique changes of cell mechanics in two types of physiological processes (stem cell differentiation, cancer metastasis) revealed by AFM were summarized. After that, the molecular mechanisms guiding cell mechanics were analyzed. Finally the challenges and future directions were discussed.
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Fang J, Wang H, Liu Y, Ding F, Ni Y, Shao S. High KRT8 expression promotes tumor progression and metastasis of gastric cancer. Cancer Sci 2017; 108:178-186. [PMID: 27865045 PMCID: PMC5329158 DOI: 10.1111/cas.13120] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 12/19/2022] Open
Abstract
Keratin8 (KRT8) is the major component of the intermediate filament cytoskeleton and predominantly expressed in simple epithelial tissues. Aberrant expression of KRT8 is associated with multiple tumor progression and metastasis. However, the role of KRT8 in gastric cancer (GC) remains unclear. In this study, KRT8 expression was investigated and it was found to be upregulated along with human GC progression and metastasis at both mRNA and protein levels in human gastric cancer tissues. In addition, KRT8 overexpression enhanced the proliferation and migration of human gastric cancer cells, whereas the knock‐down of KRT8 by siRNA only inhibited migration of human gastric cancer cells. Integrinβ1‐FAK‐induced epithelial‐mesenchymal‐transition (EMT) only existed in the high KRT8 cells. Furthermore, KRT8 overexpression led to increase in p‐smad2/3 levels and TGFβ dependent signaling events. KRT8 expression in GC was related to tumor clinical stage and worse survival. Kaplan–Meier analysis proved that KRT8 was associated with overall survival of patients with GC that patients with high KRT8 expression tend to have unfavorable outcome. Moreover, Cox's proportional hazards analysis showed that high KRT8 expression was a prognostic marker of poor outcome. These results provided that KRT8 expression may therefore be a biomarker or potential therapeutic target to identify patients with worse survival.
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Affiliation(s)
- Jian Fang
- School of Medicine, Jiangsu University, Jiangsu, China
| | - Hao Wang
- Second People's Hospital of Wuxi, Wuxi, China.,Nanjing Medical University, Nanjing, China
| | - Yun Liu
- School of Medicine, Jiangsu University, Jiangsu, China
| | - Fangfang Ding
- School of Medicine, Jiangsu University, Jiangsu, China
| | - Ying Ni
- School of Medicine, Jiangsu University, Jiangsu, China
| | - Shihe Shao
- School of Medicine, Jiangsu University, Jiangsu, China
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Mamiya A, Kitano H, Kokubun S, Hidai C. Activation peptide of coagulation factor IX regulates endothelial permeability. Transl Res 2016; 177:70-84.e5. [PMID: 27392935 DOI: 10.1016/j.trsl.2016.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/11/2016] [Accepted: 06/15/2016] [Indexed: 01/07/2023]
Abstract
Endothelial hyperpermeability is involved in several critical illnesses, and its regulatory mechanisms have been intensively investigated. It was recently reported that the activation peptide of coagulation factor IX enhances cell matrix and intercellular adhesion. The aim of this study was to investigate the role of activation peptide of coagulation factor IX in intercellular adhesion of endothelial cells and evaluate its effects on endothelial permeability. In the presence of activation peptide, cells spread with lamellipodium-like broad protrusions multidirectionally, increasing the area of adhesion to matrix by 16% within 30 minutes. In intercellular adhesion, treatment with activation peptide induced overlapping of adjacent cell edges and remodeling of intercellular adhesion sites, with colocalization of the adherens junction proteins VE-cadherin and β-catenin and a marker protein of the lateral border recycling compartment, PECAM. Activation peptide decreased gaps between cells by 66% in cultured endothelial cells and suppressed increased endothelial cell monolayer permeability induced by interleukin-1β in a dose-dependent manner. Treatment with activation peptide decreased eNOS protein expression and altered its subcellular distribution, decreasing intracellular cGMP. An analogue of cGMP suppressed the effects of activation peptide on cell spreading. In addition, the effect of activation peptide on hyperpermeability was investigated in mice injected with lipopolysaccharide. Intravenous injection of lipopolysaccharide increased lung weight by 28%, and treatment with activation peptide significantly suppressed the increase in lung weight to 5%. Our results indicate that activation peptide of factor IX regulates endothelial intercellular adhesion and thus could be used in the treatment of vascular hyperpermeability.
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Affiliation(s)
- Atsushi Mamiya
- Department of Otorhinolaryngology-Head and Neck Surgery, Nihon University School of Medicine, Tokyo, Japan
| | - Hisataka Kitano
- Department of Otorhinolaryngology-Head and Neck Surgery, Nihon University School of Medicine, Tokyo, Japan
| | - Shinichiro Kokubun
- Department of Biomedical Science, Nihon University School of Medicine, Tokyo, Japan
| | - Chiaki Hidai
- Department of Biomedical Science, Nihon University School of Medicine, Tokyo, Japan.
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Zajiczek L, Shaw M, Faruqui N, Bella A, Pawar VM, Srinivasan MA, Ryadnov MG. Nano-mechanical single-cell sensing of cell-matrix contacts. NANOSCALE 2016; 8:18105-18112. [PMID: 27734052 DOI: 10.1039/c6nr05667a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Extracellular protein matrices provide a rigidity interface exhibiting nano-mechanical cues that guide cell growth and proliferation. Cells sense such cues using actin-rich filopodia extensions which encourage favourable cell-matrix contacts to recruit more actin-mediated local forces into forming stable focal adhesions. A challenge remains in identifying and measuring these local cellular forces and in establishing empirical relationships between them, cell adhesion and filopodia formation. Here we investigate such relationships using a micromanipulation system designed to operate at the time scale of focal contact dynamics, with the sample frequency of a force probe being 0.1 ms, and to apply and measure forces at nano-to-micro Newton ranges for individual mammalian cells. We explore correlations between cell biomechanics, cell-matrix attachment forces and the spread areas of adhered cells as well as their relative dependence on filopodia formation using synthetic protein matrices with a proven ability to induce enhanced filopodia numbers in adherent cells. This study offers a basis for engineering exploitable cell-matrix contacts in situ at the nanoscale and single-cell levels.
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Affiliation(s)
- Lydia Zajiczek
- National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, UK.
| | - Michael Shaw
- National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, UK. and UCL TouchLab, Department of Computer Science, University College London, London, WC1E 6BT, UK
| | - Nilofar Faruqui
- National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, UK.
| | - Angelo Bella
- National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, UK.
| | - Vijay M Pawar
- UCL TouchLab, Department of Computer Science, University College London, London, WC1E 6BT, UK
| | - Mandayam A Srinivasan
- UCL TouchLab, Department of Computer Science, University College London, London, WC1E 6BT, UK and MIT TouchLab, Department of Mechanical Engineering and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Maxim G Ryadnov
- National Physical Laboratory, Hampton Rd, Teddington, Middlesex TW11 0LW, UK.
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Xie X, Aalipour A, Gupta SV, Melosh NA. Determining the Time Window for Dynamic Nanowire Cell Penetration Processes. ACS NANO 2015; 9:11667-77. [PMID: 26554425 DOI: 10.1021/acsnano.5b05498] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nanowire (NW) arrays offer opportunities for parallel, nondestructive intracellular access for biomolecule delivery, intracellular recording, and sensing. Spontaneous cell membrane penetration by vertical nanowires is essential for these applications, yet the time- and geometry-dependent penetration process is still poorly understood. In this work, the dynamic NW-cell interface during cell spreading was examined through experimental cell penetration measurements combined with two mechanical models based on substrate adhesion force or cell traction forces. Penetration was determined by comparing the induced tension at a series of given membrane configurations to the critical membrane failure tension. The adhesion model predicts that penetration occurs within a finite window shortly after initial cell contact and adhesion, while the traction model predicts increasing penetration over a longer period. NW penetration rates determined from a cobalt ion delivery assay are compared to the predicted results from the two models. In addition, the effects of NW geometry and cell properties are systematically evaluated to identify the key factors for penetration.
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Affiliation(s)
| | | | - Sneha V Gupta
- UCSF School of Pharmacy, Bioengineering and Therapeutic Sciences, University of California, San Francisco , San Francisco, California 94143, United States
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Gardiner BS, Wong KKL, Joldes GR, Rich AJ, Tan CW, Burgess AW, Smith DW. Discrete Element Framework for Modelling Extracellular Matrix, Deformable Cells and Subcellular Components. PLoS Comput Biol 2015; 11:e1004544. [PMID: 26452000 PMCID: PMC4599884 DOI: 10.1371/journal.pcbi.1004544] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 09/09/2015] [Indexed: 01/13/2023] Open
Abstract
This paper presents a framework for modelling biological tissues based on discrete particles. Cell components (e.g. cell membranes, cell cytoskeleton, cell nucleus) and extracellular matrix (e.g. collagen) are represented using collections of particles. Simple particle to particle interaction laws are used to simulate and control complex physical interaction types (e.g. cell-cell adhesion via cadherins, integrin basement membrane attachment, cytoskeletal mechanical properties). Particles may be given the capacity to change their properties and behaviours in response to changes in the cellular microenvironment (e.g., in response to cell-cell signalling or mechanical loadings). Each particle is in effect an ‘agent’, meaning that the agent can sense local environmental information and respond according to pre-determined or stochastic events. The behaviour of the proposed framework is exemplified through several biological problems of ongoing interest. These examples illustrate how the modelling framework allows enormous flexibility for representing the mechanical behaviour of different tissues, and we argue this is a more intuitive approach than perhaps offered by traditional continuum methods. Because of this flexibility, we believe the discrete modelling framework provides an avenue for biologists and bioengineers to explore the behaviour of tissue systems in a computational laboratory. Modelling is an important tool in understanding the behaviour of biological tissues. In this paper we advocate a new modelling framework in which cells and tissues are represented by a collection of particles with associated properties. The particles interact with each other and can change their behaviour in response to changes in their environment. We demonstrate how the propose framework can be used to represent the mechanical behaviour of different tissues with much greater flexibility as compared to traditional continuum based methods.
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Affiliation(s)
- Bruce S. Gardiner
- School of Engineering and Information Technology, Murdoch University, Perth, Australia
- * E-mail:
| | - Kelvin K. L. Wong
- Engineering Computational Biology, School of Computer Science and Software Engineering, The University of Western Australia, Perth, Australia
| | - Grand R. Joldes
- Intelligent Systems for Medicine Laboratory, School of Mechanical and Chemical Engineering, The University of Western Australia, Perth, Australia
| | - Addison J. Rich
- Engineering Computational Biology, School of Computer Science and Software Engineering, The University of Western Australia, Perth, Australia
| | - Chin Wee Tan
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Antony W. Burgess
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Surgery, Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - David W. Smith
- Engineering Computational Biology, School of Computer Science and Software Engineering, The University of Western Australia, Perth, Australia
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Ezrin is a Major Regulator of Membrane Tension in Epithelial Cells. Sci Rep 2015; 5:14700. [PMID: 26435322 PMCID: PMC4592969 DOI: 10.1038/srep14700] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 09/07/2015] [Indexed: 11/12/2022] Open
Abstract
Plasma membrane tension is responsible for a variety of cellular functions such as motility, cell division, and endocytosis. Since membrane tension is dominated by the attachment of the actin cortex to the inner leaflet of the plasma membrane, we investigated the importance of ezrin, a major cross-linker of the membrane-cytoskeleton interface, for cellular mechanics of confluent MDCK II cells. For this purpose, we carried out ezrin depletion experiments and also enhanced the number of active ezrin molecules at the interface. Mechanical properties were assessed by force indentation experiments followed by membrane tether extraction. PIP2 micelles were injected into individual living cells to reinforce the linkage between plasma membrane and actin-cortex, while weakening of this connection was reached by ezrin siRNA and administration of the inhibitors neomycin and NSC 668394, respectively. We observed substantial stiffening of cells and an increase in membrane tension after addition of PIP2 micelles. In contrast, reduction of active ezrin led to a decrease of membrane tension accompanied by loss of excess surface area, increase in cortical tension, remodelling of actin cytoskeleton, and reduction of cell height. The data confirm the importance of the ezrin-mediated connection between plasma membrane and cortex for cellular mechanics and cell morphology.
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37
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Elastic properties of epithelial cells probed by atomic force microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3075-82. [PMID: 26193077 DOI: 10.1016/j.bbamcr.2015.07.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 06/30/2015] [Accepted: 07/10/2015] [Indexed: 12/21/2022]
Abstract
Cellular mechanics plays a crucial role in many biological processes such as cell migration, cell growth, embryogenesis, and oncogenesis. Epithelia respond to environmental cues comprising biochemical and physical stimuli through defined changes in cell elasticity. For instance, cells can differentiate between certain properties such as viscoelasticity or topography of substrates by adapting their own elasticity and shape. A living cell is a complex viscoelastic body that not only exhibits a shell architecture composed of a membrane attached to a cytoskeleton cortex but also generates contractile forces through its actomyosin network. Here we review cellular mechanics of single cells in the context of epithelial cell layers responding to chemical and physical stimuli. This article is part of a Special Issue entitled: Mechanobiology.
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38
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Zhang L, Li Z, Fan Y, Li H, Li Z, Li Y. Overexpressed GRP78 affects EMT and cell-matrix adhesion via autocrine TGF-β/Smad2/3 signaling. Int J Biochem Cell Biol 2015; 64:202-11. [PMID: 25934251 DOI: 10.1016/j.biocel.2015.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/18/2015] [Accepted: 04/21/2015] [Indexed: 10/23/2022]
Abstract
Glucose-regulated protein of 78kD (GRP78) is a multifunctional protein belonging to the heat shock protein 70 family. Overexpression of GRP78 triggered by environmental and physiological stresses is positively correlated with the occurrence and progression of various tumors, but the molecular mechanisms have not been well established. The present study indicated that overexpression of GRP78 in colon cancer cells could promote cell-matrix adhesion through the upregulation of fibronectin, integrin-β1 and phosphorylated FAK. Meanwhile, it resulted in a visible epithelial-mesenchymal transition in DLD1 cells, and the Snail-2 played the key role during the process. More importantly, the data indicated that GRP78 overexpression facilitated the expression and secretion of TGF-β1, which further activated the downstream Smad2/3 signaling module to effectuate the cell-matrix adhesion and epithelial-mesenchymal transition. Taken together, this study provides a novel molecular mechanism involving in the effects of GRP78 on colon cancer metastasis.
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Affiliation(s)
- Lichao Zhang
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Zongwei Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Yongsheng Fan
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Hanqing Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Zhouyu Li
- Institute of Biotechnology, Key Laboratory of Chemical Biology and Molecular Engineering of National Ministry of Education, Shanxi University, Taiyuan 030006, China; College of Life Science, Zhejiang Chinese Medical University, Hangzhou, 310053, China.
| | - Yaoping Li
- Shanxi Tumor Hospital, Taiyuan 030006, China
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39
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Iturri J, García-Fernández L, Reuning U, García AJ, del Campo A, Salierno MJ. Synchronized cell attachment triggered by photo-activatable adhesive ligands allows QCM-based detection of early integrin binding. Sci Rep 2015; 5:9533. [PMID: 25825012 PMCID: PMC4379501 DOI: 10.1038/srep09533] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 03/04/2015] [Indexed: 12/28/2022] Open
Abstract
The Quartz Crystal Microbalance with dissipation (QCM-D) technique was applied to monitor and quantify integrin-RGD recognition during the early stages of cell adhesion. Using QCM-D crystals modified with a photo-activatable RGD peptide, the time point of presentation of adhesive ligand at the surface of the QCM-D crystal could be accurately controlled. This allowed temporal resolution of early integrin-RGD binding and the subsequent cell spreading process, and their separate detection by QCM-D. The specificity of the integrin-RGD binding event was corroborated by performing the experiments in the presence of soluble cyclicRGD as a competitor, and cytochalasin D as inhibitor of cell spreading. Larger frequency change in the QCM-D signal was observed for cells with larger spread area, and for cells overexpressing integrin αvβ3 upon stable transfection. This strategy enables quantification of integrin activity which, in turn, may allow discrimination among different cell types displaying distinct integrin subtypes and expression levels thereof. On the basis of these findings, we believe the strategy can be extended to other photoactivatable ligands to characterize cell membrane receptors activity, a relevant issue for cancer diagnosis (and prognosis) as other several pathologies.
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Affiliation(s)
- Jagoba Iturri
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | | | - Ute Reuning
- Clinical Research Unit, Dept. for Obstetrics &Gynecology, Technische Universitaet München, Munich, Germany
| | - Andrés J García
- Woodruff School of Mechanical Engineering and Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Aránzazu del Campo
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Marcelo J Salierno
- 1] Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany [2] National Scientific and Technical Research Council, Av. Rivadavia 1917, C1033AAJ CABA, Argentina
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40
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Rother J, Büchsenschütz-Göbeler M, Nöding H, Steltenkamp S, Samwer K, Janshoff A. Cytoskeleton remodelling of confluent epithelial cells cultured on porous substrates. J R Soc Interface 2015; 12:20141057. [PMID: 25566882 PMCID: PMC4305408 DOI: 10.1098/rsif.2014.1057] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 12/11/2014] [Indexed: 12/12/2022] Open
Abstract
The impact of substrate topography on the morphological and mechanical properties of confluent MDCK-II cells cultured on porous substrates was scrutinized by means of various imaging techniques as well as atomic force microscopy comprising force volume and microrheology measurements. Regardless of the pore size, ranging from 450 to 5500 nm in diameter, cells were able to span the pores. They did not crawl into the holes or grow around the pores. Generally, we found that cells cultured on non-porous surfaces are stiffer, i.e. cortical tension rises from 0.1 to 0.3 mN m(-1), and less fluid than cells grown over pores. The mechanical data are corroborated by electron microscopy imaging showing more cytoskeletal filaments on flat samples in comparison to porous ones. By contrast, cellular compliance increases with pore size and cells display a more fluid-like behaviour on larger pores. Interestingly, cells on pores larger than 3500 nm produce thick actin bundles that bridge the pores and thereby strengthen the contact zone of the cells.
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Affiliation(s)
- Jan Rother
- Institute of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Göttingen 37077, Germany
| | | | - Helen Nöding
- Institute of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Göttingen 37077, Germany
| | | | - Konrad Samwer
- I. Institute of Physics, University of Goettingen, Friedrich-Hund Platz 1, Göttingen 37077, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, University of Goettingen, Tammannstrasse 6, Göttingen 37077, Germany
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41
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Giannopoulou E, Siatis KE, Metsiou D, Kritikou I, Papachristou DJ, Kalofonou M, Koutras A, Athanassiou G, Kalofonos HP. The inhibition of aromatase alters the mechanical and rheological properties of non-small-cell lung cancer cell lines affecting cell migration. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:328-37. [PMID: 25450981 DOI: 10.1016/j.bbamcr.2014.11.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 01/10/2023]
Abstract
Tumor invasion and metastasis are key aspects of non-small cell lung cancer (NSCLC). During migration, cells undergo mechanical alterations. The mechanical phenotype of breast cancer cells is correlated with aromatase gene expression. We have previously shown that targeting aromatase is a promising strategy for NSCLC. The aim of this study was to examine morphological and mechanical changes of NSCLC cells, upon treatment with aromatase inhibitor and correlate their ability to migrate and invade. In vitro experiments were performed using H23 and A549 NSCLC cell lines and exemestane was used for aromatase inhibition. We demonstrated that exemestane reduced H23 cell migration and invasion and caused changes in cell morphology including increased vacuolar structures and greater pleomorphism. In addition, exemestane changed the distribution of α-tubulin in H23 and A549 cells in a way that might destabilize microtubules polymerization. These effects were associated with increased cell viscosity and decreased elastic shear modulus. Although exemestane caused similar effects in A549 cells regarding viscosity and elastic shear modulus, it did not affect A549 cell migration and caused an increase in invasion. The increased invasion was in line with vimentin perinuclear localization. Our data show that the treatment of NSCLC cells with an aromatase inhibitor not only affects cell migration and invasion but also alters the mechanical properties of the cells. It suggests that the different origin of cancer cells is associated with different morphological characteristics and mechanical behavior.
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Affiliation(s)
- E Giannopoulou
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece
| | - K E Siatis
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece
| | - D Metsiou
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering and Aeronautics, University of Patras, Rion, Patra 26504, Greece
| | - I Kritikou
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece
| | - D J Papachristou
- Department of Anatomy-Histology-Embryology, Unit of Bone and Soft Tissue Studies, Department of Medicine, University of Patras, Rion, 26504, Greece
| | - M Kalofonou
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece
| | - A Koutras
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece
| | - G Athanassiou
- Laboratory of Biomechanics and Biomedical Engineering, Department of Mechanical Engineering and Aeronautics, University of Patras, Rion, Patra 26504, Greece.
| | - H P Kalofonos
- Clinical Oncology laboratory, Division of Oncology, Department of Medicine, University of Patras, Rion, Patra 26504, Greece.
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Heinrich D, Ecke M, Jasnin M, Engel U, Gerisch G. Reversible membrane pearling in live cells upon destruction of the actin cortex. Biophys J 2014; 106:1079-91. [PMID: 24606932 DOI: 10.1016/j.bpj.2013.12.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 11/07/2013] [Accepted: 12/11/2013] [Indexed: 02/02/2023] Open
Abstract
Membrane pearling in live cells is observed when the plasma membrane is depleted of its support, the cortical actin network. Upon efficient depolymerization of actin, pearls of variable size are formed, which are connected by nanotubes of ~40 nm diameter. We show that formation of the membrane tubes and their transition into chains of pearls do not require external tension, and that they neither depend on microtubule-based molecular motors nor pressure generated by myosin-II. Pearling thus differs from blebbing. The pearling state is stable as long as actin is prevented from polymerizing. When polymerization is restored, the pearls are retracted into the cell, indicating continuity of the membrane. Our data suggest that the alternation of pearls and strings is an energetically favored state of the unsupported plasma membrane, and that one of the functions of the actin cortex is to prevent the membrane from spontaneously assuming this configuration.
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Affiliation(s)
- Doris Heinrich
- Leiden Institute of Physics, LION, Leiden University, The Netherlands; Fraunhofer-Institut für Silicatforschung ISC, Würzburg, Germany
| | - Mary Ecke
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Marion Jasnin
- Max Planck Institute of Biochemistry, Martinsried, Germany
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Benitez R, Toca-herrera JL. Looking at cell mechanics with atomic force microscopy: Experiment and theory. Microsc Res Tech 2014; 77:947-58. [DOI: 10.1002/jemt.22419] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 07/24/2014] [Accepted: 07/25/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Rafael Benitez
- Department of Mathematics; University Center of Plasencia, University of Extremadura, Avda. Virgen del Puerto 2; 10600 Plasencia Spain
| | - José. L. Toca-herrera
- Institute for Biophysics, Department of Nanobiotechnology; University of Natural Resources and Life Sciences Vienna (BOKU), Muthgasse 11; 1190 Vienna Austria
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Insights into the alteration of osteoblast mechanical properties upon adhesion on chitosan. BIOMED RESEARCH INTERNATIONAL 2014; 2014:740726. [PMID: 24987701 PMCID: PMC4058848 DOI: 10.1155/2014/740726] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 04/16/2014] [Accepted: 05/13/2014] [Indexed: 11/29/2022]
Abstract
Cell adhesion on substrates is accompanied by significant changes in shape and cytoskeleton organization, which affect subsequent cellular and tissue responses, determining the long-term success of an implant. Alterations in osteoblast stiffness upon adhesion on orthopaedic implants with different surface chemical composition and topography are, thus, of central interest in the field of bone implant research. This work aimed to study the mechanical response of osteoblasts upon adhesion on chitosan-coated glass surfaces and to investigate possible correlations with the level of adhesion, spreading, and cytoskeleton reorganization. Using the micropipette aspiration technique, the osteoblast elastic modulus was found higher on chitosan-coated than on uncoated control substrates, and it was found to increase in the course of spreading for both substrates. The cell-surface contact area was measured throughout several time points of adhesion to quantify cell spreading kinetics. Significant differences were found between chitosan and control surfaces regarding the response of cell spreading, while both groups displayed a sigmoidal kinetical behavior with an initially elevated spreading rate which stabilizes in the second hour of attachment. Actin filament structural changes were confirmed after observation with confocal microscope. Biomaterial surface modification can enhance osteoblast mechanical response and induce favorable structural organization for the implant integration.
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Thompson GL, Roth C, Tolstykh G, Kuipers M, Ibey BL. Disruption of the actin cortex contributes to susceptibility of mammalian cells to nanosecond pulsed electric fields. Bioelectromagnetics 2014; 35:262-72. [DOI: 10.1002/bem.21845] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 01/20/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Gary L. Thompson
- National Research Council; Joint Base San Antonio Fort Sam Houston; San Antonio Texas
| | - Caleb Roth
- Department of Radiological Sciences; University of Texas Health Science Center at San Antonio; San Antonio Texas
| | - Gleb Tolstykh
- National Research Council; Joint Base San Antonio Fort Sam Houston; San Antonio Texas
| | - Marjorie Kuipers
- Radio Frequency Bioeffects Branch; Bioeffects Division; Human Effectiveness Directorate; Air Force Research Laboratory; Joint Base San Antonio Fort Sam Houston; San Antonio Texas
| | - Bennett L. Ibey
- Radio Frequency Bioeffects Branch; Bioeffects Division; Human Effectiveness Directorate; Air Force Research Laboratory; Joint Base San Antonio Fort Sam Houston; San Antonio Texas
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46
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Dividing cells regulate their lipid composition and localization. Cell 2014; 156:428-39. [PMID: 24462247 PMCID: PMC3909459 DOI: 10.1016/j.cell.2013.12.015] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 10/16/2013] [Accepted: 12/04/2013] [Indexed: 12/18/2022]
Abstract
Although massive membrane rearrangements occur during cell division, little is known about specific roles that lipids might play in this process. We report that the lipidome changes with the cell cycle. LC-MS-based lipid profiling shows that 11 lipids with specific chemical structures accumulate in dividing cells. Using AFM, we demonstrate differences in the mechanical properties of live dividing cells and their isolated lipids relative to nondividing cells. In parallel, systematic RNAi knockdown of lipid biosynthetic enzymes identified enzymes required for division, which highly correlated with lipids accumulated in dividing cells. We show that cells specifically regulate the localization of lipids to midbodies, membrane-based structures where cleavage occurs. We conclude that cells actively regulate and modulate their lipid composition and localization during division, with both signaling and structural roles likely. This work has broader implications for the active and sustained participation of lipids in basic biology. Systematic, comprehensive lipid analyses in dividing cells and midbodies AFM shows dividing cells and their lipids have specific physical properties Screen of lipid biosynthetic enzymes reveals 23 genes required for division Perturbing lipid levels alters actin cytoskeleton and cell stiffness
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Maravillas-Montero JL, López-Ortega O, Patiño-López G, Santos-Argumedo L. Myosin 1g regulates cytoskeleton plasticity, cell migration, exocytosis, and endocytosis in B lymphocytes. Eur J Immunol 2014; 44:877-86. [PMID: 24310084 DOI: 10.1002/eji.201343873] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 10/22/2013] [Accepted: 11/27/2013] [Indexed: 11/07/2022]
Abstract
Myosin 1g (Myo1g) is a hematopoietic-specific myosin expressed mainly by lymphocytes. Here, we report the localization of Myo1g in B-cell membrane compartments such as lipid rafts, microvilli, and membrane extensions formed during spreading. By using Myo1g-deficient mouse B cells, we detected abnormalities in the adhesion ability and chemokine-induced directed migration of these lymphocytes. We also assessed a role for Myo1g in phagocytosis and exocytosis processes, as these were also irregular in Myo1g-deficient B cells. Taken together, our results show that Myo1g acts as a main regulator of different membrane/cytoskeleton-dependent processes in B lymphocytes.
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Affiliation(s)
- José L Maravillas-Montero
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, México
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48
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Schneider D, Baronsky T, Pietuch A, Rother J, Oelkers M, Fichtner D, Wedlich D, Janshoff A. Tension monitoring during epithelial-to-mesenchymal transition links the switch of phenotype to expression of moesin and cadherins in NMuMG cells. PLoS One 2013; 8:e80068. [PMID: 24339870 PMCID: PMC3855076 DOI: 10.1371/journal.pone.0080068] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 10/09/2013] [Indexed: 01/06/2023] Open
Abstract
Structural alterations during epithelial-to-mesenchymal transition (EMT) pose a substantial challenge to the mechanical response of cells and are supposed to be key parameters for an increased malignancy during metastasis. Herein, we report that during EMT, apical tension of the epithelial cell line NMuMG is controlled by cell-cell contacts and the architecture of the underlying actin structures reflecting the mechanistic interplay between cellular structure and mechanics. Using force spectroscopy we find that tension in NMuMG cells slightly increases 24 h after EMT induction, whereas upon reaching the final mesenchymal-like state characterized by a complete loss of intercellular junctions and a concerted down-regulation of the adherens junction protein E-cadherin, the overall tension becomes similar to that of solitary adherent cells and fibroblasts. Interestingly, the contribution of the actin cytoskeleton on apical tension increases significantly upon EMT induction, most likely due to the formation of stable and highly contractile stress fibers which dominate the elastic properties of the cells after the transition. The structural alterations lead to the formation of single, highly motile cells rendering apical tension a good indicator for the cellular state during phenotype switching. In summary, our study paves the way towards a more profound understanding of cellular mechanics governing fundamental morphological programs such as the EMT.
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Affiliation(s)
- David Schneider
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Thilo Baronsky
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Anna Pietuch
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Jan Rother
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Marieelen Oelkers
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
| | - Dagmar Fichtner
- Institute for Cell and Developmental Biology, Karlsruhe Institute of Technology (KIT), Fritz Haber Weg 2, Karlsruhe, Germany
| | - Doris Wedlich
- Institute for Cell and Developmental Biology, Karlsruhe Institute of Technology (KIT), Fritz Haber Weg 2, Karlsruhe, Germany
| | - Andreas Janshoff
- Institute of Physical Chemistry, Georg-August-University Göttingen, Göttingen, Germany
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Xie X, Xu AM, Angle MR, Tayebi N, Verma P, Melosh NA. Mechanical model of vertical nanowire cell penetration. NANO LETTERS 2013; 13:6002-8. [PMID: 24237230 DOI: 10.1021/nl403201a] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Direct access into cells' interiors is essential for biomolecular delivery, gene transfection, and electrical recordings yet is challenging due to the cell membrane barrier. Recently, molecular delivery using vertical nanowires (NWs) has been demonstrated for introducing biomolecules into a large number of cells in parallel. However, the microscopic understanding of how and when the nanowires penetrate cell membranes is still lacking, and the degree to which actual membrane penetration occurs is controversial. Here we present results from a mechanical continuum model of elastic cell membrane penetration through two mechanisms, namely through "impaling" as cells land onto a bed of nanowires, and through "adhesion-mediated" penetration, which occurs as cells spread on the substrate and generate adhesion force. Our results reveal that penetration is much more effective through the adhesion mechanism, with NW geometry and cell stiffness being critically important. Stiffer cells have higher penetration efficiency, but are more sensitive to NW geometry. These results provide a guide to designing nanowires for applications in cell membrane penetration.
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Affiliation(s)
- Xi Xie
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
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