1
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Seelbinder B, Wagner S, Jain M, Erben E, Klykov S, Stoev ID, Krishnaswamy VR, Kreysing M. Probe-free optical chromatin deformation and measurement of differential mechanical properties in the nucleus. eLife 2024; 13:e76421. [PMID: 38214505 PMCID: PMC10786458 DOI: 10.7554/elife.76421] [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: 12/15/2021] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
The nucleus is highly organized to facilitate coordinated gene transcription. Measuring the rheological properties of the nucleus and its sub-compartments will be crucial to understand the principles underlying nuclear organization. Here, we show that strongly localized temperature gradients (approaching 1°C/µm) can lead to substantial intra-nuclear chromatin displacements (>1 µm), while nuclear area and lamina shape remain unaffected. Using particle image velocimetry (PIV), intra-nuclear displacement fields can be calculated and converted into spatio-temporally resolved maps of various strain components. Using this approach, we show that chromatin displacements are highly reversible, indicating that elastic contributions are dominant in maintaining nuclear organization on the time scale of seconds. In genetically inverted nuclei, centrally compacted heterochromatin displays high resistance to deformation, giving a rigid, solid-like appearance. Correlating spatially resolved strain maps with fluorescent reporters in conventional interphase nuclei reveals that various nuclear compartments possess distinct mechanical identities. Surprisingly, both densely and loosely packed chromatin showed high resistance to deformation, compared to medium dense chromatin. Equally, nucleoli display particularly high resistance and strong local anchoring to heterochromatin. Our results establish how localized temperature gradients can be used to drive nuclear compartments out of mechanical equilibrium to obtain spatial maps of their material responses.
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Affiliation(s)
- Benjamin Seelbinder
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
| | - Susan Wagner
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Institute of Biological and Chemical Systems-Biological Information Processing, Karlsruhe Institute of TechnologyEggenstein-LeopoldshafenGermany
| | - Manavi Jain
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
| | - Elena Erben
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
| | - Sergei Klykov
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
| | - Iliya Dimitrov Stoev
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
| | | | - Moritz Kreysing
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Centre for Systems BiologyDresdenGermany
- Institute of Biological and Chemical Systems-Biological Information Processing, Karlsruhe Institute of TechnologyEggenstein-LeopoldshafenGermany
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2
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Mei Y, Feng X, Jin Y, Kang R, Wang X, Zhao D, Ghosh S, Neu CP, Avril S. Cell nucleus elastography with the adjoint-based inverse solver. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 242:107827. [PMID: 37801883 DOI: 10.1016/j.cmpb.2023.107827] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/09/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023]
Abstract
BACKGROUND AND OBJECTIVES The mechanics of the nucleus depends on cellular structures and architecture, and impact a number of diseases. Nuclear mechanics is yet rather complex due to heterogeneous distribution of dense heterochromatin and loose euchromatin domains, giving rise to spatially variable stiffness properties. METHODS In this study, we propose to use the adjoint-based inverse solver to identify for the first time the nonhomogeneous elastic property distribution of the nucleus. Inputs of the inverse solver are deformation fields measured with microscopic imaging in contracting cardiomyocytes. RESULTS The feasibility of the proposed method is first demonstrated using simulated data. Results indicate accurate identification of the assumed heterochromatin region, with a maximum relative error of less than 5%. We also investigate the influence of unknown Poisson's ratio on the reconstruction and find that variations of the Poisson's ratio in the range [0.3-0.5] result in uncertainties of less than 15% in the identified stiffness. Finally, we apply the inverse solver on actual deformation fields acquired within the nuclei of two cardiomyocytes. The obtained results are in good agreement with the density maps obtained from microscopy images. CONCLUSIONS Overall, the proposed approach shows great potential for nuclear elastography, with promising value for emerging fields of mechanobiology and mechanogenetics.
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Affiliation(s)
- Yue Mei
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China; Ningbo Institute of Dalian University of Technology, No. 26 Yucai Road, Jiangbei District, Ningbo 315016, China
| | - Xuan Feng
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China
| | - Yun Jin
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China
| | - Rongyao Kang
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China
| | - XinYu Wang
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China
| | - Dongmei Zhao
- State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China; International Research Center for Computational Mechanics, Dalian University of Technology, Dalian 116023, China
| | - Soham Ghosh
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, United States of America
| | - Corey P Neu
- Paul M. Rady Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, United States of America; Biomedical Engineering Program, University of Colorado Boulder, Boulder, CO, United States of America; BioFrontiers Institute, University of Colorado Boulder, Boulder, CO, United States of America
| | - Stephane Avril
- Mines Saint-Étienne, Univ Jean Monnet, INSERM, U 1059 Sainbiose, F - 42023, Saint-Étienne, France.
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3
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Hara Y. Physical forces modulate interphase nuclear size. Curr Opin Cell Biol 2023; 85:102253. [PMID: 37801797 DOI: 10.1016/j.ceb.2023.102253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/11/2023] [Accepted: 09/07/2023] [Indexed: 10/08/2023]
Abstract
The eukaryotic nucleus exhibits remarkable plasticity in size, adjusting dynamically to changes in cellular conditions such as during development and differentiation, and across species. Traditionally, the supply of structural constituents to the nuclear envelope has been proposed as the principal determinant of nuclear size. However, recent experimental and theoretical analyses have provided an alternative perspective, which emphasizes the crucial role of physical forces such as osmotic pressure and chromatin repulsion forces in regulating nuclear size. These forces can be modulated by the molecular profiles that traverse the nuclear envelope and assemble in the macromolecular complex. This leads to a new paradigm wherein multiple nuclear macromolecules that are not limited to only the structural constituents of the nuclear envelope, are involved in the control of nuclear size and related functions.
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Affiliation(s)
- Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan.
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4
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Pierangeli D, Perini G, Palmieri V, Grecco I, Friggeri G, De Spirito M, Papi M, DelRe E, Conti C. Extreme transport of light in spheroids of tumor cells. Nat Commun 2023; 14:4662. [PMID: 37537177 PMCID: PMC10400595 DOI: 10.1038/s41467-023-40379-7] [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: 07/01/2022] [Accepted: 07/14/2023] [Indexed: 08/05/2023] Open
Abstract
Extreme waves are intense and unexpected wavepackets ubiquitous in complex systems. In optics, these rogue waves are promising as robust and noise-resistant beams for probing and manipulating the underlying material. Localizing large optical power is crucial especially in biomedical systems, where, however, extremely intense beams have not yet been observed. We here discover that tumor-cell spheroids manifest optical rogue waves when illuminated by randomly modulated laser beams. The intensity of light transmitted through bio-printed three-dimensional tumor models follows a signature Weibull statistical distribution, where extreme events correspond to spatially-localized optical modes propagating within the cell network. Experiments varying the input beam power and size indicate that the rogue waves have a nonlinear origin. We show that these nonlinear optical filaments form high-transmission channels with enhanced transmission. They deliver large optical power through the tumor spheroid, and can be exploited to achieve a local temperature increase controlled by the input wave shape. Our findings shed light on optical propagation in biological aggregates and demonstrate how nonlinear extreme event formation allows light concentration in deep tissues, paving the way to using rogue waves in biomedical applications, such as light-activated therapies.
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Affiliation(s)
- Davide Pierangeli
- Institute for Complex Systems, National Research Council, Rome, 00185, Italy.
- Physics Department, Sapienza University of Rome, Rome, 00185, Italy.
| | - Giordano Perini
- Neuroscience Department, University Cattolica del Sacro Cuore, Rome, 00168, Italy
- IRCSS, Fondazione Policlinico Universitario Agostino Gemelli, Rome, 00168, Italy
| | - Valentina Palmieri
- Institute for Complex Systems, National Research Council, Rome, 00185, Italy
- Neuroscience Department, University Cattolica del Sacro Cuore, Rome, 00168, Italy
| | - Ivana Grecco
- Physics Department, Sapienza University of Rome, Rome, 00185, Italy
| | - Ginevra Friggeri
- Neuroscience Department, University Cattolica del Sacro Cuore, Rome, 00168, Italy
- IRCSS, Fondazione Policlinico Universitario Agostino Gemelli, Rome, 00168, Italy
| | - Marco De Spirito
- Neuroscience Department, University Cattolica del Sacro Cuore, Rome, 00168, Italy
- IRCSS, Fondazione Policlinico Universitario Agostino Gemelli, Rome, 00168, Italy
| | - Massimiliano Papi
- Neuroscience Department, University Cattolica del Sacro Cuore, Rome, 00168, Italy.
- IRCSS, Fondazione Policlinico Universitario Agostino Gemelli, Rome, 00168, Italy.
| | - Eugenio DelRe
- Physics Department, Sapienza University of Rome, Rome, 00185, Italy
| | - Claudio Conti
- Physics Department, Sapienza University of Rome, Rome, 00185, Italy
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5
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Heijo H, Merten CA, Hara Y. Differential contribution of nuclear size scaling mechanisms between Xenopus species. Dev Growth Differ 2022; 64:501-507. [PMID: 36308491 DOI: 10.1111/dgd.12819] [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: 05/30/2022] [Revised: 08/24/2022] [Accepted: 10/05/2022] [Indexed: 12/31/2022]
Abstract
Size of the nucleus, a membrane-bound organelle for DNA replication and transcription in eukaryotic cells, varies to adapt nuclear functions to the surrounding environment. Nuclear size strongly correlates with cytoplasmic size and genomic content. Previous studies using Xenopus laevis have unraveled two modes, cytoplasmic and chromatin-based mechanisms, for controlling nuclear size. However, owing to limited comparative analyses of the mechanisms among eukaryotic species, the contribution of each mechanism in controlling nuclear size has not been comprehensively elucidated. Here, we compared the relative contribution utilizing a cell-free reconstruction system from the cytoplasmic extract of unfertilized eggs of Xenopus tropicalis to that of the sister species X. laevis. In this system, interphase nuclei were reconstructed in vitro from sperm chromatin and increased in size throughout the incubation period. Using extracts from X. tropicalis, growth rate of the reconstructed nuclei was decreased by obstructing the effective cytoplasmic space, decreasing DNA quantity, or inhibiting molecules involved in various cytoplasmic mechanisms. Although these features are qualitatively identical to that shown by the extract of X. laevis, the sensitivities of experimental manipulation for each cellular parameter were different between the extracts from two Xenopus species. These quantitative differences implied that the contribution of each mode to expansion of the nuclear envelope is coordinated in a species-specific manner, which sets the species-specific nuclear size for in vivo physiological function.
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Affiliation(s)
- Hiroko Heijo
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yamaguchi City, Japan
| | - Christoph A Merten
- Laboratory of Biomedical Microfluidics (LBMM), Department of Bioengineering, School of Engineering, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland
| | - Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yamaguchi City, Japan
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6
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Hauck N, Beck T, Cojoc G, Schlüßler R, Ahmed S, Raguzin I, Mayer M, Schubert J, Müller P, Guck J, Thiele J. PNIPAAm microgels with defined network architecture as temperature sensors in optical stretchers. MATERIALS ADVANCES 2022; 3:6179-6190. [PMID: 35979502 PMCID: PMC9342673 DOI: 10.1039/d2ma00296e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Stretching individual living cells with light is a standard method to assess their mechanical properties. Yet, heat introduced by the laser light of optical stretchers may unwittingly change the mechanical properties of cells therein. To estimate the temperature induced by an optical trap, we introduce cell-sized, elastic poly(N-isopropylacrylamide) (PNIPAAm) microgels that relate temperature changes to hydrogel swelling. For their usage as a standardized calibration tool, we analyze the effect of free-radical chain-growth gelation (FCG) and polymer-analogous photogelation (PAG) on hydrogel network heterogeneity, micromechanics, and temperature response by Brillouin microscopy and optical diffraction tomography. Using a combination of tailor-made PNIPAAm macromers, PAG, and microfluidic processing, we obtain microgels with homogeneous network architecture. With that, we expand the capability of standardized microgels in calibrating and validating cell mechanics analysis, not only considering cell and microgel elasticity but also providing stimuli-responsiveness to consider dynamic changes that cells may undergo during characterization.
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Affiliation(s)
- Nicolas Hauck
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
| | - Timon Beck
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany
- Max Planck Institute for the Science of Light Staudtstraße 2 D-91058 Erlangen Germany
| | - Gheorghe Cojoc
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany
| | - Raimund Schlüßler
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany
| | - Saeed Ahmed
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany
| | - Ivan Raguzin
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
| | - Martin Mayer
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
| | - Jonas Schubert
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
| | - Paul Müller
- Max Planck Institute for the Science of Light Staudtstraße 2 D-91058 Erlangen Germany
| | - Jochen Guck
- Center for Molecular and Cellular Bioengineering, Biotechnology Center, Technische Universität Dresden D-01307 Dresden Germany
- Max Planck Institute for the Science of Light Staudtstraße 2 D-91058 Erlangen Germany
| | - Julian Thiele
- Leibniz-Institut für Polymerforschung Dresden e.V., Institute of Physical Chemistry and Polymer Physics D-01069 Dresden Germany
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7
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Niide T, Asari S, Kawabata K, Hara Y. Specificity of Nuclear Size Scaling in Frog Erythrocytes. Front Cell Dev Biol 2022; 10:857862. [PMID: 35663388 PMCID: PMC9159806 DOI: 10.3389/fcell.2022.857862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/21/2022] [Indexed: 11/29/2022] Open
Abstract
In eukaryotes, the cell has the ability to modulate the size of the nucleus depending on the surrounding environment, to enable nuclear functions such as DNA replication and transcription. From previous analyses of nuclear size scaling in various cell types and species, it has been found that eukaryotic cells have a conserved scaling rule, in which the nuclear size correlates with both cell size and genomic content. However, there are few studies that have focused on a certain cell type and systematically analyzed the size scaling properties in individual species (intra-species) and among species (inter-species), and thus, the difference in the scaling rules among cell types and species is not well understood. In the present study, we analyzed the size scaling relationship among three parameters, nuclear size, cell size, and genomic content, in our measured datasets of terminally differentiated erythrocytes of five Anura frogs and collected datasets of different species classes from published papers. In the datasets of isolated erythrocytes from individual frogs, we found a very weak correlation between the measured nuclear and cell cross-sectional areas. Within the erythrocytes of individual species, the correlation of the nuclear area with the cell area showed a very low hypoallometric relationship, in which the relative nuclear size decreased when the cell size increased. These scaling trends in intra-species erythrocytes are not comparable to the known general correlation in other cell types. When comparing parameters across species, the nuclear areas correlated with both cell areas and genomic contents among the five frogs and the collected datasets in each species class. However, the contribution of genomic content to nuclear size determination was smaller than that of the cell area in all species classes. In particular, the estimated degree of the contribution of genomic content was greater in the amphibian class than in other classes. Together with our imaging analysis of structural components in nuclear membranes, we hypothesized that the observed specific features in nuclear size scaling are achieved by the weak interaction of the chromatin with the nuclear membrane seen in frog erythrocytes.
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8
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Hao Y, Cheng S, Tanaka Y, Hosokawa Y, Yalikun Y, Li M. Mechanical properties of single cells: Measurement methods and applications. Biotechnol Adv 2020; 45:107648. [DOI: 10.1016/j.biotechadv.2020.107648] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 09/11/2020] [Accepted: 10/12/2020] [Indexed: 12/22/2022]
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9
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Heijo H, Shimogama S, Nakano S, Miyata A, Iwao Y, Hara Y. DNA content contributes to nuclear size control in Xenopus laevis. Mol Biol Cell 2020; 31:2703-2717. [PMID: 32997613 PMCID: PMC7927187 DOI: 10.1091/mbc.e20-02-0113] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 08/28/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022] Open
Abstract
Cells adapt to drastic changes in genome quantity during evolution and cell division by adjusting the nuclear size to exert genomic functions. However, the mechanism by which DNA content within the nucleus contributes to controlling the nuclear size remains unclear. Here, we experimentally evaluated the effects of DNA content by utilizing cell-free Xenopus egg extracts and imaging of in vivo embryos. Upon manipulation of DNA content while maintaining cytoplasmic effects constant, both plateau size and expansion speed of the nucleus correlated highly with DNA content. We also found that nuclear expansion dynamics was altered when chromatin interaction with the nuclear envelope or chromatin condensation was manipulated while maintaining DNA content constant. Furthermore, excess membrane accumulated on the nuclear surface when the DNA content was low. These results clearly demonstrate that nuclear expansion is determined not only by cytoplasmic membrane supply but also by the physical properties of chromatin, including DNA quantity and chromatin structure within the nucleus, rather than the coding sequences themselves. In controlling the dynamics of nuclear expansion, we propose that chromatin interaction with the nuclear envelope plays a role in transmitting chromatin repulsion forces to the nuclear membrane.
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Affiliation(s)
- Hiroko Heijo
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Sora Shimogama
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Shuichi Nakano
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Anna Miyata
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yasuhiro Iwao
- Laboratory of Molecular Developmental Biology, Department of Biology, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
| | - Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi City, 753-8512, Japan
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10
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Blázquez-Castro A, Fernández-Piqueras J, Santos J. Genetic Material Manipulation and Modification by Optical Trapping and Nanosurgery-A Perspective. Front Bioeng Biotechnol 2020; 8:580937. [PMID: 33072730 PMCID: PMC7530750 DOI: 10.3389/fbioe.2020.580937] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/01/2020] [Indexed: 11/13/2022] Open
Abstract
Light can be employed as a tool to alter and manipulate matter in many ways. An example has been the implementation of optical trapping, the so called optical tweezers, in which light can hold and move small objects with 3D control. Of interest for the Life Sciences and Biotechnology is the fact that biological objects in the size range from tens of nanometers to hundreds of microns can be precisely manipulated through this technology. In particular, it has been shown possible to optically trap and move genetic material (DNA and chromatin) using optical tweezers. Also, these biological entities can be severed, rearranged and reconstructed by the combined use of laser scissors and optical tweezers. In this review, the background, current state and future possibilities of optical tweezers and laser scissors to manipulate, rearrange and alter genetic material (DNA, chromatin and chromosomes) will be presented. Sources of undesirable effects by the optical procedure and measures to avoid them will be discussed. In addition, first tentative approaches at cellular-level genetic and organelle surgery, in which genetic material or DNA-carrying organelles are extracted out or introduced into cells, will be presented.
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Affiliation(s)
- Alfonso Blázquez-Castro
- Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain.,Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center (CBMSO), CSIC-Autonomous University of Madrid, Madrid, Spain
| | - José Fernández-Piqueras
- Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain.,Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center (CBMSO), CSIC-Autonomous University of Madrid, Madrid, Spain.,Institute of Health Research Jiménez Diaz Foundation, Madrid, Spain.,Consortium for Biomedical Research in Rare Diseases (CIBERER), Carlos III Institute of Health, Madrid, Spain
| | - Javier Santos
- Department of Biology, Faculty of Sciences, Autonomous University of Madrid, Madrid, Spain.,Genome Dynamics and Function Program, Genome Decoding Unit, Severo Ochoa Molecular Biology Center (CBMSO), CSIC-Autonomous University of Madrid, Madrid, Spain.,Institute of Health Research Jiménez Diaz Foundation, Madrid, Spain.,Consortium for Biomedical Research in Rare Diseases (CIBERER), Carlos III Institute of Health, Madrid, Spain
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11
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Isolated nuclei stiffen in response to low intensity vibration. J Biomech 2020; 111:110012. [PMID: 32932075 DOI: 10.1016/j.jbiomech.2020.110012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 02/03/2023]
Abstract
The nucleus, central to all cellular activity, relies on both direct mechanical input and its molecular transducers to sense and respond to external stimuli. While it has been shown that isolated nuclei can adapt to applied force ex vivo, the mechanisms governing nuclear mechanoadaptation in response to physiologic forces in vivo remain unclear. To investigate nuclear mechanoadaptation in cells, we developed an atomic force microscopy (AFM) based procedure to probe live nuclei isolated from mesenchymal stem cells (MSCs) following the application of low intensity vibration (LIV) to determine whether nuclear stiffness increases as a result of LIV. Results indicated that isolated nuclei were, on average, 30% softer than nuclei tested within intact MSCs prior to LIV. When the nucleus was isolated following LIV (0.7 g, 90 Hz, 20 min) applied four times (4×) separated by 1 h intervals, stiffness of isolated nuclei increased 75% compared to non-LIV controls. LIV-induced nuclear stiffening required functional Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, but was not accompanied by increased levels of the nuclear envelope proteins LaminA/C or Sun-2. While depleting LaminA/C or Sun-1&2 resulted in either a 47% or 39% increased heterochromatin to nuclear area ratio in isolated nuclei, the heterochromatin to nuclear area ratio was decreased by 25% in LIV-treated nuclei compared to controls, indicating LIV-induced changes in the heterochromatin structure. Overall, our findings indicate that increased apparent cell stiffness in response to exogenous mechanical challenge of MSCs in the form of LIV is in part retained by increased nuclear stiffness and changes in heterochromatin structure.
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12
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Abstract
The size of the intracellular structure that encloses genomic DNA - known as the nucleus in eukaryotes and nucleoid in prokaryotes - is believed to scale according to cell size and genomic content inside them across the tree of life. However, an actual scaling relationship remains largely unexplored across eukaryotic species. Here, I collected a large dataset of nuclear and cell volumes in diverse species across different phyla, including some prokaryotes, from the published literature and assessed the scaling relationship. Although entire inter-species data showed that nuclear volume correlates with cell volume, the quantitative scaling property exhibited differences among prokaryotes, unicellular eukaryotes and multicellular eukaryotes. Additionally, the nuclear volume correlates with genomic content inside the nucleus of multicellular eukaryotes but not of prokaryotes and unicellular eukaryotes. In this Hypothesis, I, thus, propose that the basic concept of nuclear-size scaling is conserved across eukaryotes; however, structural and mechanical properties of nuclear membranes and chromatin can result in different scaling relationships of nuclear volume to cell volume and genomic content among species. In particular, eukaryote-specific properties of the nuclear membrane may contribute to the extreme flexibility of nuclear size with regard to DNA density inside the nucleus.
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Affiliation(s)
- Yuki Hara
- Evolutionary Cell Biology Laboratory, Faculty of Science, Yamaguchi University, Yoshida 1677-1, Yamaguchi city 753-8512, Japan
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13
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Fischer T, Hayn A, Mierke CT. Effect of Nuclear Stiffness on Cell Mechanics and Migration of Human Breast Cancer Cells. Front Cell Dev Biol 2020; 8:393. [PMID: 32548118 PMCID: PMC7272586 DOI: 10.3389/fcell.2020.00393] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 04/29/2020] [Indexed: 12/18/2022] Open
Abstract
The migration and invasion of cancer cells through 3D confined extracellular matrices is coupled to cell mechanics and the mechanics of the extracellular matrix. Cell mechanics is mainly determined by both the mechanics of the largest organelle in the cell, the nucleus, and the cytoskeletal architecture of the cell. Hence, cytoskeletal and nuclear mechanics are the major contributors to cell mechanics. Among other factors, steric hindrances of the extracellular matrix confinement are supposed to affect nuclear mechanics and thus also influence cell mechanics. Therefore, we propose that the percentage of invasive cells and their invasion depths into loose and dense 3D extracellular matrices is regulated by both nuclear and cytoskeletal mechanics. In order to investigate the effect of both nuclear and cytoskeletal mechanics on the overall cell mechanics, we firstly altered nuclear mechanics by the chromatin de-condensing reagent Trichostatin A (TSA) and secondly altered cytoskeletal mechanics by addition of actin polymerization inhibitor Latrunculin A and the myosin inhibitor Blebbistatin. In fact, we found that TSA-treated MDA-MB-231 human breast cancer cells increased their invasion depth in dense 3D extracellular matrices, whereas the invasion depths in loose matrices were decreased. Similarly, the invasion depths of TSA-treated MCF-7 human breast cancer cells in dense matrices were significantly increased compared to loose matrices, where the invasion depths were decreased. These results are also valid in the presence of a matrix-metalloproteinase inhibitor GM6001. Using atomic force microscopy (AFM), we found that the nuclear stiffnesses of both MDA-MB-231 and MCF-7 breast cancer cells were pronouncedly higher than their cytoskeletal stiffness, whereas the stiffness of the nucleus of human mammary epithelial cells was decreased compared to their cytoskeleton. TSA treatment reduced cytoskeletal and nuclear stiffness of MCF-7 cells, as expected. However, a softening of the nucleus by TSA treatment may induce a stiffening of the cytoskeleton of MDA-MB-231 cells and subsequently an apparent stiffening of the nucleus. Inhibiting actin polymerization using Latrunculin A revealed a softer nucleus of MDA-MB-231 cells under TSA treatment. This indicates that the actin-dependent cytoskeletal stiffness seems to be influenced by the TSA-induced nuclear stiffness changes. Finally, the combined treatment with TSA and Latrunculin A further justifies the hypothesis of apparent nuclear stiffening, indicating that cytoskeletal mechanics seem to be regulated by nuclear mechanics.
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Affiliation(s)
- Tony Fischer
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
| | - Alexander Hayn
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
| | - Claudia Tanja Mierke
- Biological Physics Division, Peter Debye Institute of Soft Matter Physics, Faculty of Physics and Earth Sciences, Leipzig University, Leipzig, Germany
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14
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Multiple particle tracking analysis in isolated nuclei reveals the mechanical phenotype of leukemia cells. Sci Rep 2020; 10:6707. [PMID: 32317728 PMCID: PMC7174401 DOI: 10.1038/s41598-020-63682-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/02/2020] [Indexed: 12/14/2022] Open
Abstract
The nucleus is fundamentally composed by lamina and nuclear membranes that enclose the chromatin, nucleoskeletal components and suspending nucleoplasm. The functional connections of this network integrate external stimuli into cell signals, including physical forces to mechanical responses of the nucleus. Canonically, the morphological characteristics of the nucleus, as shape and size, have served for pathologists to stratify and diagnose cancer patients; however, novel biophysical techniques must exploit physical parameters to improve cancer diagnosis. By using multiple particle tracking (MPT) technique on chromatin granules, we designed a SURF (Speeded Up Robust Features)-based algorithm to study the mechanical properties of isolated nuclei and in living cells. We have determined the apparent shear stiffness, viscosity and optical density of the nucleus, and how the chromatin structure influences on these biophysical values. Moreover, we used our MPT-SURF analysis to study the apparent mechanical properties of isolated nuclei from patients of acute lymphoblastic leukemia. We found that leukemia cells exhibited mechanical differences compared to normal lymphocytes. Interestingly, isolated nuclei from high-risk leukemia cells showed increased viscosity than their counterparts from normal lymphocytes, whilst nuclei from relapsed-patient's cells presented higher density than those from normal lymphocytes or standard- and high-risk leukemia cells. Taken together, here we presented how MPT-SURF analysis of nuclear chromatin granules defines nuclear mechanical phenotypic features, which might be clinically relevant.
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15
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Chan CJ, Hiiragi T. Integration of luminal pressure and signalling in tissue self-organization. Development 2020; 147:147/5/dev181297. [DOI: 10.1242/dev.181297] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
ABSTRACT
Many developmental processes involve the emergence of intercellular fluid-filled lumina. This process of luminogenesis results in a build up of hydrostatic pressure and signalling molecules in the lumen. However, the potential roles of lumina in cellular functions, tissue morphogenesis and patterning have yet to be fully explored. In this Review, we discuss recent findings that describe how pressurized fluid expansion can provide both mechanical and biochemical cues to influence cell proliferation, migration and differentiation. We also review emerging techniques that allow for precise quantification of fluid pressure in vivo and in situ. Finally, we discuss the intricate interplay between luminogenesis, tissue mechanics and signalling, which provide a new dimension for understanding the principles governing tissue self-organization in embryonic development.
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Affiliation(s)
- Chii J. Chan
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | - Takashi Hiiragi
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
- Institute for the Advanced Study of Human Biology (WPI-ASHBi), Kyoto University, Kyoto, 606-8501, Japan
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16
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Sneider A, Hah J, Wirtz D, Kim DH. Recapitulation of molecular regulators of nuclear motion during cell migration. Cell Adh Migr 2019; 13:50-62. [PMID: 30261154 PMCID: PMC6527386 DOI: 10.1080/19336918.2018.1506654] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/05/2018] [Accepted: 07/18/2018] [Indexed: 01/12/2023] Open
Abstract
Cell migration is a highly orchestrated cellular event that involves physical interactions of diverse subcellular components. The nucleus as the largest and stiffest organelle in the cell not only maintains genetic functionality, but also actively changes its morphology and translocates through dynamic formation of nucleus-bound contractile stress fibers. Nuclear motion is an active and essential process for successful cell migration and nucleus self-repairs in response to compression and extension forces in complex cell microenvironment. This review recapitulates molecular regulators that are crucial for nuclear motility during cell migration and highlights recent advances in nuclear deformation-mediated rupture and repair processes in a migrating cell.
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Affiliation(s)
- Alexandra Sneider
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jungwon Hah
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Dong-Hwee Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, Republic of Korea
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17
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Optical Tweezers: Phototoxicity and Thermal Stress in Cells and Biomolecules. MICROMACHINES 2019; 10:mi10080507. [PMID: 31370251 PMCID: PMC6722566 DOI: 10.3390/mi10080507] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022]
Abstract
For several decades optical tweezers have proven to be an invaluable tool in the study and analysis of myriad biological responses and applications. However, as with every tool, they can have undesirable or damaging effects upon the very sample they are helping to study. In this review the main negative effects of optical tweezers upon biostructures and living systems will be presented. There are three main areas on which the review will focus: linear optical excitation within the tweezers, non-linear photonic effects, and thermal load upon the sampled volume. Additional information is provided on negative mechanical effects of optical traps on biological structures. Strategies to avoid or, at least, minimize these negative effects will be introduced. Finally, all these effects, undesirable for the most, can have positive applications under the right conditions. Some hints in this direction will also be discussed.
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18
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Jetta D, Gottlieb PA, Verma D, Sachs F, Hua SZ. Shear stress induced nuclear shrinkage through activation of Piezo1 channels in epithelial cells. J Cell Sci 2019; 132:jcs.226076. [DOI: 10.1242/jcs.226076] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/29/2019] [Indexed: 12/30/2022] Open
Abstract
The cell nucleus responds to mechanical cues with changes in size, morphology, and motility. Previous work showed that external forces couple to nuclei through the cytoskeleton network, but we show here that changes in nuclear shape can be driven solely by calcium levels. Fluid shear stress applied to MDCK cells caused the nuclei to shrink through a Ca2+ dependent signaling pathway. Inhibiting mechanosensitive Piezo1 channels with GsMTx4 prevented nuclear shrinkage. Piezo1 knockdown also significantly reduced the nuclear shrinkage. Activation of Piezo1 with the agonist Yoda1 caused similar nucleus shrinkage without shear stress. These results demonstrate that Piezo1 channel is a key element for transmitting shear force input to nuclei. To ascertain the relative contributions of Ca2+ to cytoskeleton perturbation, we examined the F-actin reorganization under shear stress and static conditions, and showed that reorganization of the cytoskeleton is not necessary for nuclear shrinkage. These results emphasize the role of the mechanosensitive channels as primary transducers in force transmission to the nucleus.
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Affiliation(s)
- Deekshitha Jetta
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Philip A. Gottlieb
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
| | - Deepika Verma
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
| | - Frederick Sachs
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
| | - Susan Z. Hua
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York 14260, USA
- Department of Physiology and Biophysics, University at Buffalo, Buffalo, New York 14260, USA
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19
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Bernal-Escalante J, López-Vázquez A, Araiza-Olivera D, Jiménez-Sánchez A. Organotin(iv) differential fluorescent probe for controlled subcellular localization and nuclear microviscosity monitoring. Chem Commun (Camb) 2019; 55:8246-8249. [DOI: 10.1039/c9cc04179f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A dual-emissive fluorescent probe based on the organotin(iv) ion enabled unique tracking of the local microviscosity through a differential and controlled nuclear–cytosolic redistribution.
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Affiliation(s)
- Jasmine Bernal-Escalante
- Instituto de Química – Universidad Nacional Autónoma de México
- Ciudad Universitaria
- De. Coyoacán 04510
- Mexico
| | - Armando López-Vázquez
- Instituto de Química – Universidad Nacional Autónoma de México
- Ciudad Universitaria
- De. Coyoacán 04510
- Mexico
| | - Daniela Araiza-Olivera
- Instituto de Química – Universidad Nacional Autónoma de México
- Ciudad Universitaria
- De. Coyoacán 04510
- Mexico
| | - Arturo Jiménez-Sánchez
- Instituto de Química – Universidad Nacional Autónoma de México
- Ciudad Universitaria
- De. Coyoacán 04510
- Mexico
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20
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Mathieu S, Manneville JB. Intracellular mechanics: connecting rheology and mechanotransduction. Curr Opin Cell Biol 2018; 56:34-44. [PMID: 30253328 DOI: 10.1016/j.ceb.2018.08.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/21/2018] [Accepted: 08/27/2018] [Indexed: 12/30/2022]
Abstract
Cell mechanics is crucial for a wide range of cell functions, including proliferation, polarity, migration and differentiation. Cells sense external physical cues and translate them into a cellular response. While force sensing occurs in the vicinity of the plasma membrane, forces can reach deep in the cell interior and to the nucleus. We review here the recent developments in the field of intracellular mechanics. We focus first on intracellular rheology, the study of the mechanical properties of the cell interior, and recapitulate the contribution of active mechanisms, the cytoskeleton and intracellular organelles to cell rheology. We then discuss how forces are transmitted inside the cell during mechanotransduction events, through direct force transmission and biochemical signaling, and how intracellular rheology and mechanotransduction are connected.
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Affiliation(s)
- Samuel Mathieu
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France; Sorbonne Université, UPMC University Paris 06, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France
| | - Jean-Baptiste Manneville
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France; Sorbonne Université, UPMC University Paris 06, CNRS, UMR 144, 26 rue d'Ulm, F-75005, Paris, France.
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21
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Lele TP, Dickinson RB, Gundersen GG. Mechanical principles of nuclear shaping and positioning. J Cell Biol 2018; 217:3330-3342. [PMID: 30194270 PMCID: PMC6168261 DOI: 10.1083/jcb.201804052] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/27/2018] [Accepted: 08/24/2018] [Indexed: 12/16/2022] Open
Abstract
Positioning and shaping the nucleus represents a mechanical challenge for the migrating cell because of its large size and resistance to deformation. Cells shape and position the nucleus by transmitting forces from the cytoskeleton onto the nuclear surface. This force transfer can occur through specialized linkages between the nuclear envelope and the cytoskeleton. In response, the nucleus can deform and/or it can move. Nuclear movement will occur when there is a net differential in mechanical force across the nucleus, while nuclear deformation will occur when mechanical forces overcome the mechanical resistance of the various structures that comprise the nucleus. In this perspective, we review current literature on the sources and magnitude of cellular forces exerted on the nucleus, the nuclear envelope proteins involved in transferring cellular forces, and the contribution of different nuclear structural components to the mechanical response of the nucleus to these forces.
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Affiliation(s)
- Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL .,Anatomy and Cell Biology, University of Florida, Gainesville, FL
| | | | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Columbia University, New York, NY
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22
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Chang CC, Wang K, Zhang Y, Chen D, Fan B, Hsieh CH, Wang J, Wu MH, Chen J. Mechanical property characterization of hundreds of single nuclei based on microfluidic constriction channel. Cytometry A 2018; 93:822-828. [PMID: 30063818 DOI: 10.1002/cyto.a.23386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/18/2018] [Accepted: 04/02/2018] [Indexed: 12/31/2022]
Abstract
As label-free biomarkers, the mechanical properties of nuclei are widely treated as promising biomechanical markers for cell type classification and cellular status evaluation. However, previously reported mechanical parameters were derived from only around 10 nuclei, lacking statistical significances due to low sample numbers. To address this issue, nuclei were first isolated from SW620 and A549 cells, respectively, using a chemical treatment method. This was followed by aspirating them through two types of microfluidic constriction channels for mechanical property characterization. In this study, hundreds of nuclei were characterized, producing passage times of 0.5 ± 1.2 s for SW620 nuclei in type I constriction channel (n = 153), 0.045 ± 0.047 s for SW620 nuclei in type II constriction channel (n = 215) and 0.50 ± 0.86 s for A549 nuclei in type II constriction channel. In addition, neural network based pattern recognition was used to classify the nuclei isolated from SW620 and A549 cells, producing successful classification rates of 87.2% for diameters of nuclei, 85.5% for passage times of nuclei and 89.3% for both passage times and diameters of nuclei. These results indicate that the characterization of the mechanical properties of nuclei may contribute to the classification of different tumor cells.
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Affiliation(s)
- Chun-Chieh Chang
- Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan City, Taiwan
| | - Ke Wang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yi Zhang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Deyong Chen
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Beiyuan Fan
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Chia-Hsun Hsieh
- Division of Haematology/Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan
| | - Junbo Wang
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Min-Hsien Wu
- Graduate Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan City, Taiwan.,Division of Haematology/Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan City, Taiwan
| | - Jian Chen
- State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China.,School of Electronic, Electrical and Communication Engineering/School of Future Technology, University of Chinese Academy of Sciences, Beijing, People's Republic of China
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