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Wohlrab S, Mueller S, Gekle S. Mechanical complexity of living cells can be mapped onto simple homogeneous equivalents. Biomech Model Mechanobiol 2024:10.1007/s10237-024-01823-9. [PMID: 38411900 DOI: 10.1007/s10237-024-01823-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 01/19/2024] [Indexed: 02/28/2024]
Abstract
Biological cells are built up from different constituents of varying size and stiffness which all contribute to the cell's mechanical properties. Despite this heterogeneity, in the analysis of experimental measurements one often assumes a strongly simplified homogeneous cell and thus a single elastic modulus is assigned to the entire cell. This ad-hoc simplification has so far mostly been used without proper justification. Here, we use computer simulations to show that indeed a mechanically heterogeneous cell can effectively be replaced by a homogeneous equivalent cell with a volume averaged elastic modulus. To demonstrate the validity of this approach, we investigate a hyperelastic cell with a heterogeneous interior under compression and in shear/channel flow mimicking atomic force and microfluidic measurements, respectively. We find that the homogeneous equivalent cell reproduces quantitatively the behavior of its heterogeneous counterpart, and that this equality is largely independent of the stiffness or spatial distribution of the heterogeneity.
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Affiliation(s)
- Sebastian Wohlrab
- Theoretische Physik VI, Biofluid Simulation and Modeling, Universität Bayreuth, 95440, Bayreuth, Germany.
| | - Sebastian Mueller
- Theoretische Physik VI, Biofluid Simulation and Modeling, Universität Bayreuth, 95440, Bayreuth, Germany
| | - Stephan Gekle
- Theoretische Physik VI, Biofluid Simulation and Modeling, Universität Bayreuth, 95440, Bayreuth, Germany
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2
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Bui VC, Nguyen TH. Mechanics of Leukemic T-Cell. J Mol Recognit 2023:e3019. [PMID: 37061787 DOI: 10.1002/jmr.3019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 04/12/2023] [Indexed: 04/17/2023]
Abstract
Cell mechanics is a factor that determines cell growth, migration, proliferation, or differentiation, as well as trafficking inside the cytoplasm and organization of organelles. Knowledge about cell mechanics is critical to gaining insight into these biological processes. Here, we used atomic force microscopy to examine the elasticity, an important parameter of cell mechanics, of non-adherent Jurkat leukemic T-cells in both interphase and mitotic phases. We found that the elasticity of an individual cell does not significantly change at interphase. When a cell starts to divide, its elasticity increases in the transition from metaphase to telophase during normal division while the cell is stiffened right after it enters mitosis during abnormal division. At the end of the division, the cell elasticity gradually returned to the value of the mother cell. These changes may originate from the changes in cell surface tension during modulating actomyosin at the cleavage furrow, redistributing cell organelles, and constricting the contractile ring to sever mother cell to form daughters. The difference in elasticity patterns suggests that there is a discrepancy in the redistribution of the cell organelles during normal and abnormal division. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Van-Chien Bui
- ZIK HIKE - Center for Innovation Competence, Humoral Immune Reactions in Cardiovascular Diseases, University of Greifswald, Greifswald, Germany
| | - Thi-Huong Nguyen
- Institute for Bioprocessing and Analytical Measurement Techniques (iba), 37308 Heiligenstadt, Germany
- Institute for Chemistry and Biotechnology, Faculty of Mathematics and Natural Sciences, Technische Universität Ilmenau, Ilmenau, Germany
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3
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Grala M, Kołodziejczyk AM, Białkowska K, Walkowiak B, Komorowski P. Assessment of the influence of gold nanoparticles stabilized with PAMAM dendrimers on HUVEC barrier cells. Micron 2023; 168:103430. [PMID: 36905752 DOI: 10.1016/j.micron.2023.103430] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 02/01/2023] [Accepted: 02/25/2023] [Indexed: 03/03/2023]
Abstract
Civilization diseases, cancer, frequent mutations of viruses and other pathogens constitute the need to look for new drugs, as well as systems for their targeted delivery. One of the promising way of using drugs is supplying them by linking to nanostructures. One of the solution for the development of nanobiomedicine are metallic nanoparticles stabilized with various polymer structures. In this report, we present the synthesis of gold nanoparticles, their stabilization with polyamidoamine (PAMAM) dendrimers with ethylenediamine core and the characteristics of the obtained product (AuNPs/PAMAM). The presence, size and morphology of synthesized gold nanoparticles were evaluated by ultraviolet-visible light spectroscopy, transmission electron microscopy and atomic force microscopy. The hydrodynamic radius distribution of the colloids was analyzed by dynamic light scattering technique. Additionally, the cytotoxicity and changes in mechanical properties of human umbilical vein endothelial cell line (HUVEC) cells caused by AuNPs/PAMAM were assessed. The results of studies on the nanomechanical properties of cells suggest a two-step changes in cell elasticity as a response to contact with nanoparticles. When using AuNPs/PAMAM in lower concentrations, no changes in cell viability were observed and the cells were softer than untreated cells. When higher concentrations were used, a decrease in the cells viability to about 80 % were observed, as well as non-physiological stiffening of the cells. The presented results may play a significant role in the development of nanomedicine.
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Affiliation(s)
- Magdalena Grala
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd, Lodz, Poland; Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd, Lodz, Poland
| | - Agnieszka M Kołodziejczyk
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd, Lodz, Poland; Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd, Lodz, Poland.
| | - Kamila Białkowska
- Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd, Lodz, Poland
| | - Bogdan Walkowiak
- Department of Biophysics, Institute of Materials Science and Engineering, Lodz University of Technology, Lodz, Poland
| | - Piotr Komorowski
- Nanomaterial Structural Research Laboratory, Bionanopark Ltd, Lodz, Poland; Molecular and Nanostructural Biophysics Laboratory, Bionanopark Ltd, Lodz, Poland
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4
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Reches M, Duanis-Assaf T. In Situ Measurements of Cell Mechanical Properties Using Force Spectroscopy. Methods Mol Biol 2023; 2600:25-43. [PMID: 36587088 DOI: 10.1007/978-1-0716-2851-5_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mechanobiology focuses on how physical forces and the mechanical properties of cells and whole tissues affect their function. The mechanical properties of cells are of particular interest to developmental biology and stem cell differentiation, lymphocyte activation and phagocytic action in phagocytes, and development of malignant tumors and metastases. These properties can be measured on whole tissue and cell culture. Advances in instrument sensitivity and design, as well as improved techniques and scientific know-how achieved over the past few decades, allow researchers to study the mechanical properties of single cells and even at the subcellular level. Particularly, nanoindentation measurements using atomic force microscopy (AFM) mechanically probes single cells and even allows mapping of these traits. This chapter discusses these measurements from the experimental design to the analysis.
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Barati Shoorche A, Mohammadkarim A, Jadidi M, Bahraminasab M. Photobiomodulation Therapy Affects the Elastic Modulus, Cytoskeletal Rearrangement and Migration Capability of Human Osteosarcoma Cells. Lasers Med Sci 2022; 37:2855-2863. [PMID: 35394552 DOI: 10.1007/s10103-022-03554-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 03/28/2022] [Indexed: 11/25/2022]
Abstract
Photobiomodulation (PBM) therapy utilizes low-power lasers to modulate the viability of living human cells and leads to changes in proliferation, differentiation, adhesion and gene expression, even though the rearrangement of cytoskeleton was not previously studied. The present study aims to evaluate the photobiological effects on the elastic behavior of human osteosarcoma cells (MG-63) and their morphological changes. Fluorescence staining, confocal imaging and atomic force microscopy (AFM) topography were performed to study the effects of PBM therapy with the exposure of 532 nm-25mW, 650 nm-3mW, 650 nm-150mW and 780 nm-70mW beams following the 5-min continuous irradiation. The area of each beam was 3.14cm2 with a source-surface distance of 20 cm. Besides the cell proliferation assessment, the migratory potential of MG-63 was determined with the wound healing technique. The results indicated an increase in stiffness and shape index of radiation-induced cells 24 h after exposure along with the obvious F-actins changes. But, cell stiffening was not observed 72 h after 532 nm laser irradiation. Also, a decrease in the migration rate was seen in all of the groups after 72 h of irradiation except cells treated with 532 nm wavelength. However, 532 nm laser beams increase the migratory potential 24 h after exposure. Within 72 h after irradiation, the cell proliferation was only affected by applying 532 nm and 650 nm-150mW laser beams. It was concluded that applying photobiomodulation with wavelengths of 650 nm (at both utilized powers) and 780 nm alters the migration capability and provides a quantitative description of cytoskeletal changes. Moreover, membrane stiffening can be considered as the biological marker of PBM treatments.
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Affiliation(s)
- Amin Barati Shoorche
- Department of Medical Physics, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Alireza Mohammadkarim
- Department of Medical Physics, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
| | - Majid Jadidi
- Department of Medical Physics, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Marjan Bahraminasab
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
- Department of Tissue Engineering and Applied Cell Sciences, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
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6
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Chen Z, Yip TF, Zhu Y, Ho JWK, Chen H. The method to quantify cell elasticity based on the precise measurement of pressure inducing cell deformation in microfluidic channels. MethodsX 2021; 8:101247. [PMID: 34434770 PMCID: PMC8374187 DOI: 10.1016/j.mex.2021.101247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 01/20/2021] [Indexed: 01/01/2023] Open
Abstract
The cell elasticity has attracted extensive research interests since it not only provides new insights into cell biology but also is an emerging mechanical marker for the diagnosis of some diseases. This paper reports the method for the precise measurement of mechanical properties of single cells deformed to a large extent using a novel microfluidic system integrated with a pressure feedback system and small particle separation unit. The particle separation system was employed to avoid the blockage of the cell deformation channel to enhance the measurement throughput. This system is of remarkable application potential in the precise evaluation of cell mechanical properties. In brief, this paper reports:The manufacturing of the chip using standard soft lithography; The methods to deform single cells in a microchannel and measure the relevant pressure drop using a pressure sensor connecting to the microfluidic chip; Calculation of the mechanical properties including stiffness and fluidity of each cell based on a power-law rheology model describing the viscoelastic behaviors of cells; Automatic and real-time measurement of the mechanical properties using video processing software.
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Affiliation(s)
- Zhenlin Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Tsz Fung Yip
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Hong Kong, China.,Laboratory of Data Discovery for Health Limited (D24H), Hong Kong Science Park, New Territory, Hong Kong, China
| | - Yonggang Zhu
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
| | - Joshua W K Ho
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam Hong Kong, China.,Laboratory of Data Discovery for Health Limited (D24H), Hong Kong Science Park, New Territory, Hong Kong, China
| | - Huaying Chen
- School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China
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Papadakis L, Kanakousaki D, Bakopoulou A, Tsouknidas A, Michalakis K. A finite element model of an osteoblast to quantify the transduction of exogenous forces to cellular components. Med Eng Phys 2021; 94:61-69. [PMID: 34303503 DOI: 10.1016/j.medengphy.2021.06.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 06/12/2021] [Accepted: 06/28/2021] [Indexed: 01/16/2023]
Abstract
Encouraged by recent advances of biophysical and biochemical assays we introduce a 3D finite element model of an osteoblast, seeking an analogue between exogenous forces and intracellularly activated sensory mechanisms. The cell was reverse engineered and the dimensions of the internal cellular structures were based on literature data. The model was verified and validated against atomic force microscopy experiments and four loading scenarios were considered. The stress distributions developing on the main cellular components were calculated along with their corresponding strain values. The nucleus and mitochondria exhibited similar loading trends, with the mitochondria being stressed by an order of magnitude higher than the nucleus (e.g. 1.4 vs. 0.16 MPa). Equivalent stiffness was determined to increase by almost 50%, from the apex to the cell's periphery, as was the cell's elasticity, which was lowest when the load was exerted directly above the nucleus. The assessment of how extrinsic loads are propagated to a cell's internal structures is inherently a problem of high complexity. The findings presented in this study can provide important insight into biophysical and biochemical responses elicited in cells through mechanical stimulus. This was evident in both the nuclear and mitochondrial loading and would stipulate the important contribution of even more accurate models in the interpretation of cellular events. One Sentence Summary: The results of this numerical biomechanical study demonstrated that even minor extrinsic loads irrespective of the application site, are transduced by a fraction of the cytoskeleton to its internal structure (primarily to its mitochondria and secondary to the cell's nucleus), indicating mechanical stimulus as the dominant pathway to cell expression.
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Affiliation(s)
- Labros Papadakis
- Laboratory for Biomaterials and Computational Mechanics, Department of Mechanical Engineering, University of Western Macedonia, Bakola & Sialvera, GR-50132, Kozani, Greece
| | - Dimitra Kanakousaki
- School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki GR-54124, Thessaloniki, Greece
| | - Athina Bakopoulou
- School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki GR-54124, Thessaloniki, Greece
| | - Alexander Tsouknidas
- Laboratory for Biomaterials and Computational Mechanics, Department of Mechanical Engineering, University of Western Macedonia, Bakola & Sialvera, GR-50132, Kozani, Greece.
| | - Konstantinos Michalakis
- School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki GR-54124, Thessaloniki, Greece; Division of Postgraduate Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, 02111, USA.
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8
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Lacaria L, Lange JR, Goldmann WH, Rico F, Alonso JL. αvβ3 integrin expression increases elasticity in human melanoma cells. Biochem Biophys Res Commun 2020; 525:836-840. [PMID: 32164941 DOI: 10.1016/j.bbrc.2020.02.156] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 02/26/2020] [Indexed: 01/10/2023]
Abstract
Living cells interact with the extracellular matrix (ECM) transducing biochemical signals into mechanical cues and vice versa. Thanks to this mechano-transduction process, cells modify their internal organization and upregulate their physiological functions differently. In this complex mechanism integrins play a fundamental role, connecting the extracellular matrix with the cytoskeleton. Cytoskeletal rearrangements, such as the increase of the overall contractility, impact cell mechanical properties, the entire cell stiffness, and cell deformability. How cell mechanics is influenced via different integrins and their interaction with ECM in health and disease is still unclear. Here, we investigated the influence of αvβ3 integrin expression on the mechanics of human melanoma M21 cells using atomic force microscopy and micro-constriction. Evidence is provided that (i) αvβ3 integrin expression in human melanoma cells increases cell stiffness in both adherent and non-adherent conditions; (ii) replacing αvβ3 with αIIbβ3 integrin in melanoma cells, cell stiffness is increased under adherent, while decreased under non-adherent conditions; (iii) αvβ3 integrin cell stiffening is also maintained when cells adhere to fibronectin, but this phenomenon does not strongly depend on the fibronectin concentration. In all, this study sheds light on the role of αvβ3 in regulating cellular mechanics.
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Affiliation(s)
- Leda Lacaria
- Aix Marseille Univ, CNRS, INSERM, LAI, Marseille, France
| | - Janina R Lange
- Dept. of Biophysics, Friedrich-Alexander-University, 91052, Erlangen, Germany
| | - Wolfgang H Goldmann
- Dept. of Biophysics, Friedrich-Alexander-University, 91052, Erlangen, Germany.
| | - Felix Rico
- Aix Marseille Univ, CNRS, INSERM, LAI, Marseille, France
| | - José Luis Alonso
- Dept. of Medicine, Mass General Hospital/Harvard Medical School, Charlestown, MA, 02129, USA
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Rusaczonek M, Zapotoczny B, Szymonski M, Konior J. Application of a layered model for determination of the elasticity of biological systems. Micron 2019; 124:102705. [PMID: 31252332 DOI: 10.1016/j.micron.2019.102705] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/22/2023]
Abstract
Elasticity of biological systems is considered to be an important property that might be related to functional or pathological changes. Therefore, careful study and detailed understanding of cell and tissue elasticity is crucial for correct description of their functioning. Atomic Force Microscopy (AFM) is a powerful technique, which allows for determination of the physical properties, such as elasticity, of soft-matter systems in nano-scale. An important step in AFM elasticity studies is a proper interpretation of experimental data. Two most frequently used theoretical schemes applied to determine elasticity are due to Hertz and Sneddon, which are effectively one-parameter models. In this work, we go beyond this approach. Firstly, as elasticity is a local property, we extract from the slope of experimental force-indentation curve an elasticity parameter, which varies with indentation depth. Then secondly, we find best approximation of this parameter by applying the two-layer model with four effective parameters, as proposed by Kovalev. This method is employed to the experimental data taken on murine liver sinusoidal endothelial cells in non-alcoholic fatty liver disease model. The obtained results show additional effects, not seen within the traditional, simplified scheme. Namely, the elasticity of the first layer does not change its value in the model of non-alcoholic fatty liver disease, but the increase of stiffness is noticed in second layer. The second goal of this article is to reveal and discuss the differences between traditional approaches and the one being presented. The deviations from the original assumptions are analysed and the corresponding restrictions on utility of theoretical models are presented.
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Affiliation(s)
- M Rusaczonek
- Marian Smoluchowski Institute of Physics, Department of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, 30-059 Kraków, Poland.
| | - B Zapotoczny
- Marian Smoluchowski Institute of Physics, Department of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, 30-059 Kraków, Poland
| | - M Szymonski
- Marian Smoluchowski Institute of Physics, Department of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, 30-059 Kraków, Poland
| | - J Konior
- Marian Smoluchowski Institute of Physics, Department of Physics, Astronomy, and Applied Computer Science, Jagiellonian University, 30-059 Kraków, Poland
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Blaue C, Kashef J, Franz CM. Cadherin-11 promotes neural crest cell spreading by reducing intracellular tension-Mapping adhesion and mechanics in neural crest explants by atomic force microscopy. Semin Cell Dev Biol 2018; 73:95-106. [PMID: 28919310 DOI: 10.1016/j.semcdb.2017.08.058] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 08/24/2017] [Accepted: 08/28/2017] [Indexed: 11/21/2022]
Abstract
During development cranial neural crest cells (NCCs) display a striking transition from collective to single-cell migration, but the mechanisms enabling individual NCCs to separate from the neural crest tissue are still incompletely understood. In this study we have employed atomic force microscopy (AFM) to investigate potential adhesive and mechanical changes associated with the dissociation of individual cells from cohesive Xenopus NCC explants at early stages of migration. AFM-based single-cell force spectroscopy (SCFS) revealed a uniform distribution of cell-cell adhesion forces within NCC explants, including semi-detached leader cells in the process of delaminating from the explant edge. This suggested that dissociation from the cell sheet may not require prior weakening of cell-cell contacts. However, mapping NCC sheet elasticity by AFM microbead indentation demonstrated strongly reduced cell stiffness in semi-detached leader cells compared to neighbouring cells in the NCC sheet periphery. Reduced leader cell stiffness coincided with enhanced cell spreading and high substrate traction, indicating a possible mechano-regulation of leader cell delamination. In support, AFM elasticity measurements of individual NCCs in optical side view mode demonstrated that reducing cell tension by inhibiting actomyosin contractility induces rapid spreading, possibly maximizing cell-substrate interactions as a result. Depletion of cadherin-11, a classical cadherin with an essential role in NCC migration and substrate adhesion, prevented the tension reduction necessary for NCC spreading, both in individual cells and at the edge of explanted sheets. In contrast, overexpression of cadherin-11 accelerated spreading of both individual cells and delaminating leader cells. As cadherin-11 expression increases strongly during NCC migration, this suggests an important role of cadherin-11 in regulating NCC elasticity and spreading at later stages of NCC migration. We therefore propose a model in which high tension at the NCC sheet periphery prevents premature NCC spreading and delamination during early stages of migration, while a cadherin-11-dependent local decrease in cell tension promotes leader cell spreading and delamination at later stages of migration.
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Abstract
Atomic force microscopy (AFM) is becoming increasingly used in the biology field. It can give highly accurate topography and biomechanical quantitative data, such as adhesion, elasticity, and viscosity, on living samples. Nowadays, correlative light electron microscopy is a must-have tool in the biology field that combines different microscopy techniques to spatially and temporally analyze the structure and function of a single sample. Here, we describe the combination of AFM with superresolution light microscopy and electron microscopy. We named this technique correlative light atomic force electron microscopy (CLAFEM) in which AFM can be used on fixed and living cells in association with superresolution light microscopy and further processed for transmission or scanning electron microscopy. We herein illustrate this approach to observe cellular bacterial infection and cytoskeleton. We show that CLAFEM brings complementary information at the cellular level, from on the one hand protein distribution and topography at the nanometer scale and on the other hand elasticity at the piconewton scales to fine ultrastructural details.
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Affiliation(s)
- Sébastien Janel
- Univ. Lille, CNRS UMR 8204, Inserm U1019, CHU Lille, Institut Pasteur de Lille - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Elisabeth Werkmeister
- Univ. Lille, CNRS UMR 8204, Inserm U1019, CHU Lille, Institut Pasteur de Lille - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Antonino Bongiovanni
- Univ. Lille, CNRS UMR 8204, Inserm U1019, CHU Lille, Institut Pasteur de Lille - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Frank Lafont
- Univ. Lille, CNRS UMR 8204, Inserm U1019, CHU Lille, Institut Pasteur de Lille - CIIL - Center for Infection and Immunity of Lille, Lille, France
| | - Nicolas Barois
- Univ. Lille, CNRS UMR 8204, Inserm U1019, CHU Lille, Institut Pasteur de Lille - CIIL - Center for Infection and Immunity of Lille, Lille, France
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12
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Abstract
Polysialic acid (polySia) is an important carbohydrate bio-polymer that is commonly over-expressed on tumours of neuroendocrine origin and plays a key role in tumour progression. polySia exclusively decorates the neural cell adhesion molecule (NCAM) on tumour cell membranes, modulating cell-cell interactions, motility and invasion. In this preliminary study, we examine the nano-mechanical properties of isogenic C6 rat glioma cells-transfected cells engineered to express the enzyme polysialyltransferase ST8SiaII, which synthesises polySia (C6-STX cells) and wild-type cells (C6-WT). We demonstrate that polySia expression leads to reduced elastic and adhesive properties but also more viscoelastic compared to non-expressing wild-type cells. Whilst differences in cell elasticity between healthy and cancer cells are regularly assigned to changes in the cytoskeleton, we show that in this model system, the change in properties at the nano-level is due to the polySia on the transfected cell membrane surface.
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13
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Chen J, Zhang J, Cao J, Xia Z, Gan J. Inflammatory MAPK and NF-κB signaling pathways differentiated hepatitis potential of two agglomerated titanium dioxide particles. J Hazard Mater 2016; 304:370-378. [PMID: 26590873 DOI: 10.1016/j.jhazmat.2015.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/30/2015] [Accepted: 11/02/2015] [Indexed: 06/05/2023]
Abstract
TiO2 nanoparticles (TiO2NPs) consumption and deposit in liver have possible implications for hepatitis risks. Specific signal dysregulation at early inflammatory responses needs to be characterized in TiO2NP-induced hepatopathy. MAPK and NF-κB signaling pathways are known to participate in inflammation and respond sensitively to chemical agents, making them preferable biomarkers for hepatitis. In the present study, dynamic activation of MAPK and NF-κB pathways were explored by immunoblotting and NF-κB luciferase reporter assay depending on characterization of TiO2NP agglomeration in human HepG2 cells. Inflammatory and cytotoxic potential of TiO2NPs were determined by qRT-PCR and WST-1 assay. AFM and TEM analyses uncovered ultrastructure damages underlying hepatotoxicity of TiO2NPs. Rod-like rutile agglomerated smaller and induced more pronounced cytotoxicity and immunogenicity than anatase. Correspondingly, though both rutile and anatase significantly activated p38, ERK1/2 and NF-κB pathways, rutile accelerated the maximum phosphorylation of ERK1/2 and elevated the potency of IκBα phosphorylation to its bell curve shape in comparison with a lower and sigmoid type of IκBα phosphorylation for anatase. Furthermore, cell elasticity indicated by Young's modulus and adhesion force increased accompanied with mitochondria damage, contributing to signal dysregulation and hepatotoxicity. The results suggested that differential activation of MAPK and NF-κB pathways could be early predictors for distinct hepatitis risks of two agglomerated TiO2NPs.
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Affiliation(s)
- Jin Chen
- Environmental Science Institute, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Jianying Zhang
- Environmental Science Institute, Zhejiang University, Hangzhou, Zhejiang, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou, Zhejiang, China.
| | - Junmei Cao
- Environmental Science Institute, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Zongping Xia
- Life Sciences Institute, Zhejiang University, Hangzhou, China.
| | - Jay Gan
- Department of Environmental Sciences, University of California, Riverside, CA, USA.
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14
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Siamantouras E, Hills CE, Squires PE, Liu KK. Quantifying cellular mechanics and adhesion in renal tubular injury using single cell force spectroscopy. Nanomedicine 2015; 12:1013-1021. [PMID: 26733260 DOI: 10.1016/j.nano.2015.12.362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2015] [Revised: 11/01/2015] [Accepted: 12/02/2015] [Indexed: 01/06/2023]
Abstract
UNLABELLED Tubulointerstitial fibrosis represents the major underlying pathology of diabetic nephropathy where loss of cell-to-cell adhesion is a critical step. To date, research has predominantly focussed on the loss of cell surface molecular binding events that include altered protein ligation. In the current study, atomic force microscopy single cell force spectroscopy (AFM-SCFS) was used to quantify changes in cellular stiffness and cell adhesion in TGF-β1 treated kidney cells of the human proximal tubule (HK2). AFM indentation of TGF-β1 treated HK2 cells showed a significant increase (42%) in the elastic modulus (stiffness) compared to control. Fluorescence microscopy confirmed that increased cell stiffness is accompanied by reorganization of the cytoskeleton. The corresponding changes in stiffness, due to F-actin rearrangement, affected the work of detachment by changing the separation distance between two adherent cells. Overall, our novel data quantitatively demonstrate a correlation between cellular elasticity, adhesion and early morphologic/phenotypic changes associated with tubular injury. FROM THE CLINICAL EDITOR Diabetes affects many patients worldwide. One of the long term problems is diabetic nephropathy. Here, the authors utilized atomic force microscopy single cell force spectroscopy (AFM- SCFS) to study cellular stiffness and cell adhesion after TGF1 treatment in human proximal tubule kidney cells. The findings would help further understand the overall disease mechanism in diabetic patients.
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Affiliation(s)
| | - Claire E Hills
- School of Life Sciences, University of Lincoln, Lincoln, UK
| | - Paul E Squires
- School of Life Sciences, University of Lincoln, Lincoln, UK
| | - Kuo-Kang Liu
- School of Engineering, University of Warwick, Coventry, UK.
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15
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Del Favero G, Sosa S, Poli M, Tubaro A, Sbaizero O, Lorenzon P. In vivo and in vitro effects of 42-hydroxy-palytoxin on mouse skeletal muscle: structural and functional impairment. Toxicol Lett 2014; 225:285-93. [PMID: 24378260 DOI: 10.1016/j.toxlet.2013.12.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 11/23/2022]
Abstract
Palytoxins (PLTXs) are known seafood contaminants and their entrance into the food chain raises concern about possible effects on human health. The increasing number of analogs being identified in edible marine organisms complicates the estimation of the real hazard associated with the presence of PLTX-like compounds. So far, 42-OH-PLTX is one of the few congeners available, and the study of its toxicity represents an important step toward a better comprehension of the mechanism of action of this family of compounds. From this perspective, the aim of this work was to investigate the in vivo and in vitro effect of 42-OH-PLTX on skeletal muscle, one of the most sensitive targets for PLTXs. Our results demonstrate that 42-OH-PLTX causes damage at the skeletal muscle level with a cytotoxic potency similar to that of PLTX. 42-OH-PLTX induces cytotoxicity and cell swelling in a Na(+)-dependent manner similar to the parent compound. However, the limited Ca(2+)-dependence of the toxic insult induced by 42-OH-PLTX suggests a specific mechanism of action for this analog. Our results also suggest an impaired response to the physiological agonist acetylcholine and altered cell elasticity.
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16
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Koczurkiewicz P, Podolak I, Skrzeczyńska-Moncznik J, Sarna M, Wójcik KA, Ryszawy D, Galanty A, Lasota S, Madeja Z, Czyż J, Michalik M. Triterpene saponosides from Lysimachia ciliata differentially attenuate invasive potential of prostate cancer cells. Chem Biol Interact 2013; 206:6-17. [PMID: 23954719 DOI: 10.1016/j.cbi.2013.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 07/25/2013] [Accepted: 08/05/2013] [Indexed: 01/06/2023]
Abstract
Neither androgen ablation nor chemotherapeutic agents are effective in reducing the risk of prostate cancer progression. On the other hand, multifaceted effects of phytochemicals, such as triterpene saponins, on cancer cells have been suggested. A promising safety and tolerability profile indicate their possible application in the treatment of advanced prostate cancers. We analyzed the specificity, selectivity and versatility of desglucoanagalloside B effects on human prostate cancer cells derived from prostate cancer metastases to brain (DU-145 cells) and bone (PC-3 cells). Prominent growth arrest and apoptotic response of both cell types was observed in the presence of sub-micromolar desglucoanagalloside B concentrations. This was accompanied by cytochrome c release and caspase 3/7 activation. A relatively low cytostatic and pro-apoptotic response of cancer cells to a desglucoanagalloside B analog, anagallosaponin IV, illustrated the specificity of the effects of desglucoanagalloside B, whereas the low sensitivity of normal prostate PNT2 cells to desglucoanagalloside B showed the selectivity of its action. Inhibition of cancer cell motility was observed in the presence of both saponins, however only desglucoanagalloside B attenuated cancer cell invasive potential, predominantly through an effect on cell elastic properties. These data demonstrate the versatility of its effects on prostate cancer cells. In contrast to PNT2 cells, cancer cells tested in this study were relatively resistant to mitoxantrone. The multifaceted action of desglucoanagalloside B on basic cellular traits, crucial for prostate cancer progression, opens perspectives for elaboration of combined palliative therapies and new prostate cancer prophylaxis regimens.
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Affiliation(s)
- Paulina Koczurkiewicz
- Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland; Department of Pharmacognosy, Pharmaceutical Faculty, Medical College, Jagiellonian University, Medyczna 9, 30-688 Kraków, Poland
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