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Tang W, Wang J, Jiang A, Sun Y. Stiffening of the Cytoplasm in Response to Intracellularly Applied Forces. NANO LETTERS 2024. [PMID: 39377302 DOI: 10.1021/acs.nanolett.4c03979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
Cells constantly encounter mechanical forces that regulate various cellular functions, such as migration, division, and differentiation. Understanding how cells respond to forces at the intracellular level is essential for elucidating the mechanical adaptability of living cells. This study investigates how the cytoplasm alters its mechanical properties in response to forces applied inside a cell. The mechanical properties were measured through in situ characterization using magnetic tweezers to apply mechanical forces on magnetic beads internalized into cells. The findings reveal that the cytoplasm stiffens within seconds when force is applied to the cytoplasm. Macromolecular crowding and cytoskeletal structures, particularly F-actin, were found to significantly contribute to cytoplasm stiffening. The stiffening response was also observed across multiple length scales by using magnetic beads of varying diameters. These results highlight the rapid adaptation of the cytoplasm to mechanical forces applied to the inside of a cell.
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Affiliation(s)
- Wentian Tang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
| | - Jintian Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
| | - Aojun Jiang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, M5S 3G4, Canada
- Department of Computer Science, University of Toronto, Toronto, M5S 3G4, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S 3G9, Canada
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2
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Kahle ER, Patel N, Sreenivasappa HB, Marcolongo MS, Han L. Targeting cell-matrix interface mechanobiology by integrating AFM with fluorescence microscopy. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 176:67-81. [PMID: 36055517 PMCID: PMC9691605 DOI: 10.1016/j.pbiomolbio.2022.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 08/14/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Mechanosensing at the interface of a cell and its surrounding microenvironment is an essential driving force of physiological processes. Understanding molecular activities at the cell-matrix interface has the potential to provide novel targets for improving tissue regeneration and early disease intervention. In the past few decades, the advancement of atomic force microscopy (AFM) has offered a unique platform for probing mechanobiology at this crucial microdomain. In this review, we describe key advances under this topic through the use of an integrated system of AFM (as a biomechanical testing tool) with complementary immunofluorescence (IF) imaging (as an in situ navigation system). We first describe the body of work investigating the micromechanics of the pericellular matrix (PCM), the immediate cell micro-niche, in healthy, diseased, and genetically modified tissues, with a focus on articular cartilage. We then summarize the key findings in understanding cellular biomechanics and mechanotransduction, in which, molecular mechanisms governing transmembrane ion channel-mediated mechanosensing, cytoskeleton remodeling, and nucleus remodeling have been studied in various cell and tissue types. Lastly, we provide an overview of major technical advances that have enabled more in-depth studies of mechanobiology, including the integration of AFM with a side-view microscope, multiple optomicroscopy, a fluorescence recovery after photobleaching (FRAP) module, and a tensile stretching device. The innovations described here have contributed greatly to advancing the fundamental knowledge of extracellular matrix biomechanics and cell mechanobiology for improved understanding, detection, and intervention of various diseases.
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Affiliation(s)
- Elizabeth R Kahle
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Neil Patel
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - Harini B Sreenivasappa
- Cell Imaging Center, Office of Research and Innovation, Drexel University, PA 19104, United States
| | - Michele S Marcolongo
- Department of Mechanical Engineering, Villanova University, Villanova, PA 19085, United States
| | - Lin Han
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States.
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3
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Study of Ethinyl Estradiol Activity Against Promastigotes, Axenic and Macrophage-Dwelling Amastigotes of Leishmania infantum by Using Atomic Force Microscopy and Methyl Thiazolyl Tetrazolium Methods. Jundishapur J Microbiol 2019. [DOI: 10.5812/jjm.90857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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4
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Janel S, Popoff M, Barois N, Werkmeister E, Divoux S, Perez F, Lafont F. Stiffness tomography of eukaryotic intracellular compartments by atomic force microscopy. NANOSCALE 2019; 11:10320-10328. [PMID: 31106790 DOI: 10.1039/c8nr08955h] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Precise localization and biophysical characterization of cellular structures is a key to the understanding of biological processes happening both inside the cell and at the cell surface. Atomic force microscopy is a powerful tool to study the cell surface - topography, elasticity, viscosity, interactions - and also the viscoelastic behavior of the underlying cytoplasm, cytoskeleton or the nucleus. Here, we demonstrate the ability of atomic force microscopy to also map and characterize organelles and microorganisms inside cells, at the nanoscale, by combining stiffness tomography with super-resolution fluorescence and electron microscopy. By using this correlative approach, we could both identify and characterize intracellular compartments. The validation of this approach was performed by monitoring the stiffening effect according to the metabolic status of the mitochondria in living cells in real-time.
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Affiliation(s)
- Sébastien Janel
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U1019, CHU Lille, Institut Pasteur de Lille, Univ Lille, F-59000 Lille, France.
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5
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Efremov YM, Velay-Lizancos M, Weaver CJ, Athamneh AI, Zavattieri PD, Suter DM, Raman A. Anisotropy vs isotropy in living cell indentation with AFM. Sci Rep 2019; 9:5757. [PMID: 30962474 PMCID: PMC6453879 DOI: 10.1038/s41598-019-42077-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/18/2019] [Indexed: 12/30/2022] Open
Abstract
The measurement of local mechanical properties of living cells by nano/micro indentation relies on the foundational assumption of locally isotropic cellular deformation. As a consequence of assumed isotropy, the cell membrane and underlying cytoskeleton are expected to locally deform axisymmetrically when indented by a spherical tip. Here, we directly observe the local geometry of deformation of membrane and cytoskeleton of different living adherent cells during nanoindentation with the integrated Atomic Force (AFM) and spinning disk confocal (SDC) microscope. We show that the presence of the perinuclear actin cap (apical stress fibers), such as those encountered in cells subject to physiological forces, causes a strongly non-axisymmetric membrane deformation during indentation reflecting local mechanical anisotropy. In contrast, axisymmetric membrane deformation reflecting mechanical isotropy was found in cells without actin cap: cancerous cells MDA-MB-231, which naturally lack the actin cap, and NIH 3T3 cells in which the actin cap is disrupted by latrunculin A. Careful studies were undertaken to quantify the effect of the live cell fluorescent stains on the measured mechanical properties. Using finite element computations and the numerical analysis, we explored the capability of one of the simplest anisotropic models – transverse isotropy model with three local mechanical parameters (longitudinal and transverse modulus and planar shear modulus) – to capture the observed non-axisymmetric deformation. These results help identifying which cell types are likely to exhibit non-isotropic properties, how to measure and quantify cellular deformation during AFM indentation using live cell stains and SDC, and suggest modelling guidelines to recover quantitative estimates of the mechanical properties of living cells.
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Affiliation(s)
- Yuri M Efremov
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA.,Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA
| | | | - Cory J Weaver
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA.,University of South Carolina, Department of Biological Sciences, Jones PSC Building, 712 Main Street, room 517, Columbia, SC, 29208, USA
| | - Ahmad I Athamneh
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA.,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Pablo D Zavattieri
- Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana, USA
| | - Daniel M Suter
- Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA. .,Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA. .,Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA. .,Purdue Institute for Integrative Neuroscience, West Lafayette, Indiana, USA.
| | - Arvind Raman
- School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA. .,Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana, USA.
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6
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Basoli F, Giannitelli SM, Gori M, Mozetic P, Bonfanti A, Trombetta M, Rainer A. Biomechanical Characterization at the Cell Scale: Present and Prospects. Front Physiol 2018; 9:1449. [PMID: 30498449 PMCID: PMC6249385 DOI: 10.3389/fphys.2018.01449] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
The rapidly growing field of mechanobiology demands for robust and reproducible characterization of cell mechanical properties. Recent achievements in understanding the mechanical regulation of cell fate largely rely on technological platforms capable of probing the mechanical response of living cells and their physico–chemical interaction with the microenvironment. Besides the established family of atomic force microscopy (AFM) based methods, other approaches include optical, magnetic, and acoustic tweezers, as well as sensing substrates that take advantage of biomaterials chemistry and microfabrication techniques. In this review, we introduce the available methods with an emphasis on the most recent advances, and we discuss the challenges associated with their implementation.
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Affiliation(s)
- Francesco Basoli
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | | | - Manuele Gori
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Pamela Mozetic
- Center for Translational Medicine, International Clinical Research Center, St. Anne's University Hospital, Brno, Czechia
| | - Alessandra Bonfanti
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Marcella Trombetta
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Alberto Rainer
- Department of Engineering, Università Campus Bio-Medico di Roma, Rome, Italy.,Institute for Photonics and Nanotechnologies, National Research Council, Rome, Italy
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7
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Mapping heterogeneity of cellular mechanics by multi-harmonic atomic force microscopy. Nat Protoc 2018; 13:2200-2216. [DOI: 10.1038/s41596-018-0031-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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8
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Ikai A, Afrin R, Saito M, Watanabe-Nakayama T. Atomic force microscope as a nano- and micrometer scale biological manipulator: A short review. Semin Cell Dev Biol 2017; 73:132-144. [PMID: 28739341 DOI: 10.1016/j.semcdb.2017.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 07/16/2017] [Accepted: 07/19/2017] [Indexed: 11/27/2022]
Abstract
The amazing capacity of atomic force microscope to let us touch the molecular and cellular level samples with a sharp probe stimulated its application to bio-medical field among others. In addition to topographical imaging of the sample surface, a direct mechanical manipulation has attracted innovative minds to develop new methodologies aiming at direct handling of proteins, DNA/RNA, and cells. Measurement of their mechanical properties brought about a vivid picture of their physical nature. Direct handling of individual molecules and cells prompted development of nano-medical applications. This short review summarized recent application of AFM for measurement of mechanical properties of biological samples and attempts to perform direct manipulations of nano-medicine.
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Affiliation(s)
- Atsushi Ikai
- Innovation Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
| | - Rehana Afrin
- Innovation Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
| | - Masakazu Saito
- Innovation Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
| | - Takahiro Watanabe-Nakayama
- Innovation Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, 226-8501, Japan.
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9
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Handschuh-Wang S, Wang T, Zhou X. Recent advances in hybrid measurement methods based on atomic force microscopy and surface sensitive measurement techniques. RSC Adv 2017. [DOI: 10.1039/c7ra08515j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
This review summaries the recent progress of the combination of optical and non-optical surface sensitive techniques with the atomic force microscopy.
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Affiliation(s)
- Stephan Handschuh-Wang
- College of Chemistry and Environmental Engineering
- Shenzhen University
- Shenzhen 518060
- P. R. China
| | - Tao Wang
- Functional Thin Films Research Center
- Shenzhen Institutes of Advanced Technology
- Chinese Academy of Sciences
- Shenzhen 518055
- P. R. China
| | - Xuechang Zhou
- College of Chemistry and Environmental Engineering
- Shenzhen University
- Shenzhen 518060
- P. R. China
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10
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Barlow BM, Bertrand M, Joós B. Relaxation of a simulated lipid bilayer vesicle compressed by an atomic force microscope. Phys Rev E 2016; 94:052408. [PMID: 27967024 DOI: 10.1103/physreve.94.052408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Indexed: 06/06/2023]
Abstract
Using coarse-grained molecular dynamics simulations, we study the relaxation of bilayer vesicles, uniaxially compressed by an atomic force microscope cantilever. The relaxation time exhibits a strong force dependence. Force-compression curves are very similar to recent experiments wherein giant unilamellar vesicles were compressed in a nearly identical manner.
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Affiliation(s)
- Ben M Barlow
- Ottawa-Carleton Institute for Physics, University of Ottawa Campus, Ottawa, Ontario, Canada K1N 6N5
| | - Martine Bertrand
- Ottawa-Carleton Institute for Physics, University of Ottawa Campus, Ottawa, Ontario, Canada K1N 6N5
| | - Béla Joós
- Ottawa-Carleton Institute for Physics, University of Ottawa Campus, Ottawa, Ontario, Canada K1N 6N5
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11
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Li Y, Honda S, Iwami K, Ohta Y, Umeda N. Analysis of mitochondrial mechanical dynamics using a confocal fluorescence microscope with a bent optical fibre. J Microsc 2015; 260:140-51. [PMID: 26249642 DOI: 10.1111/jmi.12277] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Accepted: 05/26/2015] [Indexed: 01/09/2023]
Abstract
The cells in the cardiovascular system are constantly subjected to mechanical forces created by blood flow and the beating heart. The effect of forces on cells has been extensively investigated, but their effect on cellular organelles such as mitochondria remains unclear. We examined the impact of nano-Newton forces on mitochondria using a bent optical fibre (BOF) with a flat-ended tip (diameter exceeding 2 μm) and a confocal fluorescence microscope. By indenting a single mitochondrion with the BOF tip, we found that the mitochondrial elastic modulus was proportional to the (-1/2) power of the mitochondrial radius in the 9.6-115 kPa range. We stained the mitochondria with a potential-metric dye (TMRE) and measured the changes in TMRE fluorescence intensity. We confirmed that more active mitochondria exhibit a higher frequency of repetitive transient depolarization. The same trend was observed at forces lower than 50 nN. We further showed that the depolarization frequency of mitochondria decreases under an extremely large force (nearly 100 nN). We conclude that mitochondrial function is affected by physical environmental factors, such as external forces at the nano-Newton level.
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Affiliation(s)
- Yongbo Li
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Satoshi Honda
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Kentaro Iwami
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Yoshihiro Ohta
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Norihiro Umeda
- Department of Mechanical Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
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12
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Haase K, Pelling AE. Investigating cell mechanics with atomic force microscopy. J R Soc Interface 2015; 12:20140970. [PMID: 25589563 PMCID: PMC4345470 DOI: 10.1098/rsif.2014.0970] [Citation(s) in RCA: 223] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/18/2014] [Indexed: 12/12/2022] Open
Abstract
Transmission of mechanical force is crucial for normal cell development and functioning. However, the process of mechanotransduction cannot be studied in isolation from cell mechanics. Thus, in order to understand how cells 'feel', we must first understand how they deform and recover from physical perturbations. Owing to its versatility, atomic force microscopy (AFM) has become a popular tool to study intrinsic cellular mechanical properties. Used to directly manipulate and examine whole and subcellular reactions, AFM allows for top-down and reconstitutive approaches to mechanical characterization. These studies show that the responses of cells and their components are complex, and largely depend on the magnitude and time scale of loading. In this review, we generally describe the mechanotransductive process through discussion of well-known mechanosensors. We then focus on discussion of recent examples where AFM is used to specifically probe the elastic and inelastic responses of single cells undergoing deformation. We present a brief overview of classical and current models often used to characterize observed cellular phenomena in response to force. Both simple mechanistic models and complex nonlinear models have been used to describe the observed cellular behaviours, however a unifying description of cell mechanics has not yet been resolved.
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Affiliation(s)
- Kristina Haase
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada
| | - Andrew E Pelling
- Department of Physics, Centre for Interdisciplinary NanoPhysics, MacDonald Hall, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario, Canada Department of Biology, Gendron Hall, 30 Marie Curie, University of Ottawa, Ottawa, Ontario, Canada Institute for Science Society and Policy, Desmarais Building, 55 Laurier Ave. East, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5
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13
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Haase K, Pelling AE. Resiliency of the plasma membrane and actin cortex to large-scale deformation. Cytoskeleton (Hoboken) 2013; 70:494-514. [PMID: 23929821 DOI: 10.1002/cm.21129] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 07/23/2013] [Accepted: 07/29/2013] [Indexed: 01/05/2023]
Abstract
The tight coupling between the plasma membrane and actin cortex allows cells to rapidly change shape in response to mechanical cues and during physiological processes. Mechanical properties of the membrane are critical for organizing the actin cortex, which ultimately governs the conversion of mechanical information into signaling. The cortex has been shown to rapidly remodel on timescales of seconds to minutes, facilitating localized deformations and bundling dynamics that arise during the exertion of mechanical forces and cellular deformations. Here, we directly visualized and quantified the time-dependent deformation and recovery of the membrane and actin cortex of HeLa cells in response to externally applied loads both on- and off-nucleus using simultaneous confocal and atomic force microscopy. The local creep-like deformation of the membrane and actin cortex depends on both load magnitude and duration and does not appear to depend on cell confluency. The membrane and actin cortex rapidly recover their initial shape after prolonged loading (up to 10 min) with large forces (up to 20 nN) and high aspect ratio deformations. Cytoplasmic regions surrounding the nucleus are shown to be more resistant to long-term creep than nuclear regions. These dynamics are highly regulated by actomyosin contractility and an intact actin cytoskeleton. Results suggest that in response to local deformations, the nucleus does not appear to provide significant resistance or play a major role in cell shape recovery. The membrane and actin cortex clearly possess remarkable mechanical stability, critical for the transduction of mechanical deformation into long term biochemical signals and cellular remodeling.
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Affiliation(s)
- Kristina Haase
- Department of Physics, University of Ottawa, MacDonald Hall, 150 Louis Pasteur, Ottawa, Ontario, Canada
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14
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Dufrêne YF, Pelling AE. Force nanoscopy of cell mechanics and cell adhesion. NANOSCALE 2013; 5:4094-4104. [PMID: 23535827 DOI: 10.1039/c3nr00340j] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Cells are constantly exposed to mechanical stimuli in their environment and have several evolved mechanisms to sense and respond to these cues. It is becoming increasingly recognized that many cell types, from bacteria to mammalian cells, possess a diverse set of proteins to translate mechanical cues into biochemical signalling and to mediate cell surface interactions such as cell adhesion. Moreover, the mechanical properties of cells are involved in regulating cell function as well as serving as indicators of disease states. Importantly, the recent development of biophysical tools and nanoscale methods has facilitated a deeper understanding of the role that physical forces play in modulating cell mechanics and cell adhesion. Here, we discuss how atomic force microscopy (AFM) has recently been used to investigate cell mechanics and cell adhesion at the single-cell and single-molecule levels. This knowledge is critical to our understanding of the molecular mechanisms that govern mechanosensing, mechanotransduction, and mechanoresponse in living cells. While pushing living cells with the AFM tip provides a means to quantify their mechanical properties and examine their response to nanoscale forces, pulling single surface proteins with a functionalized tip allows one to understand their role in sensing and adhesion. The combination of these nanoscale techniques with modern molecular biology approaches, genetic engineering and optical microscopies provides a powerful platform for understanding the sophisticated functions of the cell surface machinery, and its role in the onset and progression of complex diseases.
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Affiliation(s)
- Yves F Dufrêne
- Université catholique de Louvain, Institute of Life Sciences, Croix du Sud, 1, bte L7.04.01., B-1348 Louvain-la-Neuve, Belgium.
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15
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Satori CP, Henderson MM, Krautkramer EA, Kostal V, Distefano MM, Arriaga EA. Bioanalysis of eukaryotic organelles. Chem Rev 2013; 113:2733-811. [PMID: 23570618 PMCID: PMC3676536 DOI: 10.1021/cr300354g] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chad P. Satori
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Michelle M. Henderson
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Elyse A. Krautkramer
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Vratislav Kostal
- Tescan, Libusina trida 21, Brno, 623 00, Czech Republic
- Institute of Analytical Chemistry ASCR, Veveri 97, Brno, 602 00, Czech Republic
| | - Mark M. Distefano
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
| | - Edgar A. Arriaga
- Department of Chemistry, University of Minnesota, Twin Cities, Minneapolis, MN, USA, 55455
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16
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Silberberg YR, Pelling AE. Quantification of intracellular mitochondrial displacements in response to nanomechanical forces. Methods Mol Biol 2013; 991:185-193. [PMID: 23546670 DOI: 10.1007/978-1-62703-336-7_18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mechanical stress affects various aspects of cell behavior, including cell growth, morphology, differentiation, and genetic expression. Here, we describe a method to quantify the intracellular mechanical response to an extracellular mechanical perturbation, specifically the displacement of mitochondria. A combined fluorescent-atomic force microscope (AFM) was used to simultaneously produce well-defined nanomechanical stimulation to a living cell while optically recording the real-time displacement of fluorescently labeled mitochondria. A single-particle tracking (SPT) approach was then applied in order to quantify the two-dimensional displacement of mitochondria in response to local forces.
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Affiliation(s)
- Yaron R Silberberg
- Biomedical Research Institute (BMRI), National Institute of Advanced Industrial Science and Technology (AIST), Kyoto University, Kyoto, Japan
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17
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Guolla L, Bertrand M, Haase K, Pelling AE. Force transduction and strain dynamics in actin stress fibres in response to nanonewton forces. J Cell Sci 2012; 125:603-13. [PMID: 22389400 DOI: 10.1242/jcs.088302] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
It is becoming clear that mechanical stimuli are crucial factors in regulating the biology of the cell, but the short-term structural response of a cell to mechanical forces remains relatively poorly understood. We mechanically stimulated cells transiently expressing actin-EGFP with controlled forces (0-20 nN) in order to investigate the structural response of the cell. Two clear force-dependent responses were observed: a short-term (seconds) local deformation of actin stress fibres and a long-term (minutes) force-induced remodelling of stress fibres at cell edges, far from the point of contact. By photobleaching markers along stress fibres we were also able to quantify strain dynamics occurring along the fibres throughout the cell. The results reveal that the cell exhibits complex heterogeneous negative and positive strain fluctuations along stress fibres in resting cells that indicate localized contraction and stretch dynamics. The application of mechanical force results in the activation of myosin contractile activity reflected in an ~50% increase in strain fluctuations. This approach has allowed us to directly observe the activation of myosin in response to mechanical force and the effects of cytoskeletal crosslinking on local deformation and strain dynamics. The results demonstrate that force application does not result in simplistic isotropic deformation of the cytoarchitecture, but rather a complex and localized response that is highly dependent on an intact microtubule network. Direct visualization of force-propagation and stress fibre strain dynamics have revealed several crucial phenomena that take place and ultimately govern the downstream response of a cell to a mechanical stimulus.
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Affiliation(s)
- Louise Guolla
- Department of Physics, MacDonald Hall, 150 Louis Pasteur, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
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18
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Kučera O, Havelka D. Mechano-electrical vibrations of microtubules--link to subcellular morphology. Biosystems 2012; 109:346-55. [PMID: 22575306 DOI: 10.1016/j.biosystems.2012.04.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 04/23/2012] [Indexed: 01/19/2023]
Abstract
Spontaneous mechanical oscillations were predicted and experimentally proven on almost every level of cellular structure. Besides morphogenetic potential of oscillatory mechanical force, oscillations may drive vibrations of electrically polar structures or these structures themselves may oscillate on their own natural frequencies. Vibrations of electric charge will generate oscillating electric field, role of which in morphogenesis is discussed in this paper. This idea is demonstrated in silico on the conformation of two growing microtubules.
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Affiliation(s)
- Ondřej Kučera
- Institute of Photonics and Electronics, Academy of Sciences of the Czech Republic, Chaberská 57, 182 51 Prague, Czechia.
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19
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Abstract
This chapter describes methods for isolating and imaging metabolically and toxicologically challenged mitochondria with atomic force microscopy. Mitochondria were isolated from rat dorsal root ganglia or brain and exposed to glucose or dinitrobenzene (DNB) to simulate the cellular environment of a diabetic animal that has been exposed to excess glucose or to DNB. It is one of only a few articles to present images of membrane structures, such as voltage-dependent, anion-selective channel pores, on intact organelles. The purpose of the chapter is not to report on the metabolic or toxic effects, but to communicate in more detail than a typical journal paper allows the methods used to image isolated organelles. We also provide a series images revealing the outer membrane and outer membrane pores. An image of an isolated nucleus as well as a set of notes written to avoid common pitfalls in isolation, labeling, and imaging is also included.
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Affiliation(s)
- Bradley E Layton
- Applied Computing and Electronics, The University of Montana College of Technology, Missoula, MT, USA.
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Hakari T, Sekiguchi H, Osada T, Kishimoto K, Afrin R, Ikai A. Nonlinear displacement of ventral stress fibers under externally applied lateral force by an atomic force microscope. Cytoskeleton (Hoboken) 2011; 68:628-38. [PMID: 21976314 DOI: 10.1002/cm.20537] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/11/2011] [Accepted: 09/27/2011] [Indexed: 01/07/2023]
Abstract
Actin-based stress fibers (SFs) have fundamental importance in the maintenance of mechanical stability of living cells. Several in vitro measurements of their elastic properties have therefore been made, but direct mechanical manipulation of individual SFs in vivo for the determination of their mechanical properties has not been attempted. No less important is a search for the possible formation of a global mechanical network involving SFs and other intracellular filamentous components. In this article, we present an application of atomic force microscopy to probe into a live cell and laterally push selected SFs in a fibroblast cells (VNOf 06 fibroblast-like cells derived from rat vomeronasal tissue) transfected with a green fluorescent protein-β-actin gene. The transfected cells were transferred to a serum-depleted medium before the atomic force microscope manipulation. The lateral displacement of the SFs under a point loading condition recorded on a fluorescence microscope revealed both linear and nonlinear displacements against the contour distance from the point of force loading. The nonlinear displacements of the SFs were attributed to their association with a cortical actomyosin-cell membrane complex that effectively pulled them back as a 2D thin plate.
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Affiliation(s)
- Tomoro Hakari
- Department of Molecular Bioscience, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Midori-ku, Yokohama, Japan
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21
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Abstract
The atomic force microscope (AFM) is a high-resolution scanning-probe instrument which has become an important tool for cellular and molecular biophysics in recent years, but lacks the time resolution and functional specificities offered by fluorescence microscopic techniques. The advantages of both methods may be exploited by combining and synchronizing them. In this paper, the biological applications of AFM, fluorescence, and their combinations are briefly reviewed, and the assembly and utilization of a spatially and temporally synchronized AFM and total internal reflection fluorescence microscope are described. The application of the method is demonstrated on a fluorescently labeled cell culture.
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Affiliation(s)
- Miklós S Z Kellermayer
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
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Wang N, Tytell JD, Ingber DE. Mechanotransduction at a distance: mechanically coupling the extracellular matrix with the nucleus. Nat Rev Mol Cell Biol 2009; 10:75-82. [DOI: 10.1038/nrm2594] [Citation(s) in RCA: 1267] [Impact Index Per Article: 84.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Cyclic Hydraulic Pressure and Fluid Flow Differentially Modulate Cytoskeleton Re-Organization in MC3T3 Osteoblasts. Cell Mol Bioeng 2008; 2:133-143. [PMID: 20161062 DOI: 10.1007/s12195-008-0038-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Mechanical loads are essential towards maintaining bone mass and skeletal integrity. Such loads generate various stimuli at the cellular level, including cyclic hydraulic pressure (CHP) and fluid shear stress (FSS). To gain insight into the anabolic responses of osteoblasts to CHP and FSS, we subjected MC3T3-E1 preosteoblasts to either FSS (12 dynes/cm(2)) or CHP varying from 0 to 68 kPa at 0.5 Hz. As with FSS, CHP produced a significant increase in ATP release over static controls within 5 min of onset. Cell stiffness examined by atomic force microscopy increased after 15 min of either CHP or FSS stimulation, which was attenuated when extracellular ATP was hydrolyzed with apyrase. As previously shown FSS induced polymerization of actins into stress fibers. However, the microtubule network was completely disrupted under FSS. In contrast, CHP appeared to maintain strong microtubule and f-actin networks. The purinergic signaling was found to be involved in the remodeling of f-actin, but not microtubule. Both CHP and FSS applied for 1 hour increased expression of COX-2. These data indicate that, while CHP and FSS produce similar anabolic responses, these stimuli have very different effects on the cytoskeleton remodeling and could contribute to loss of mechanosensitivity with extended loading.
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