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Giverso C, Loy N, Lucci G, Preziosi L. Cell orientation under stretch: A review of experimental findings and mathematical modelling. J Theor Biol 2023; 572:111564. [PMID: 37391125 DOI: 10.1016/j.jtbi.2023.111564] [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: 04/22/2023] [Accepted: 06/15/2023] [Indexed: 07/02/2023]
Abstract
The key role of electro-chemical signals in cellular processes had been known for many years, but more recently the interplay with mechanics has been put in evidence and attracted substantial research interests. Indeed, the sensitivity of cells to mechanical stimuli coming from the microenvironment turns out to be relevant in many biological and physiological circumstances. In particular, experimental evidence demonstrated that cells on elastic planar substrates undergoing periodic stretches, mimicking native cyclic strains in the tissue where they reside, actively reorient their cytoskeletal stress fibres. At the end of the realignment process, the cell axis forms a certain angle with the main stretching direction. Due to the importance of a deeper understanding of mechanotransduction, such a phenomenon was studied both from the experimental and the mathematical modelling point of view. The aim of this review is to collect and discuss both the experimental results on cell reorientation and the fundamental features of the mathematical models that have been proposed in the literature.
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Affiliation(s)
- Chiara Giverso
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Nadia Loy
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Giulio Lucci
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
| | - Luigi Preziosi
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, Turin, 10126, Italy.
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2
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Colombi A, Preziosi L, Scianna M. Modelling Cell Orientation Under Stretch: The Effect of Substrate Elasticity. Bull Math Biol 2023; 85:79. [PMID: 37460873 PMCID: PMC10352433 DOI: 10.1007/s11538-023-01180-1] [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: 12/29/2022] [Accepted: 06/19/2023] [Indexed: 07/20/2023]
Abstract
When cells are seeded on a cyclically deformed substrate like silicon, they tend to reorient their major axis in two ways: either perpendicular to the main stretching direction, or forming an oblique angle with it. However, when the substrate is very soft such as a collagen gel, the oblique orientation is no longer observed, and the cells align either along the stretching direction, or perpendicularly to it. To explain this switch, we propose a simplified model of the cell, consisting of two elastic elements representing the stress fiber/focal adhesion complexes in the main and transverse directions. These elements are connected by a torsional spring that mimics the effect of crosslinking molecules among the stress fibers, which resist shear forces. Our model, consistent with experimental observations, predicts that there is a switch in the asymptotic behaviour of the orientation of the cell determined by the stiffness of the substratum, related to a change from a supercritical bifurcation scenario, whereby the oblique configuration is stable for a sufficiently large stiffness, to a subcritical bifurcation scenario at a lower stiffness. Furthermore, we investigate the effect of cell elongation and find that the region of the parameter space leading to an oblique orientation decreases as the cell becomes more elongated. This implies that elongated cells, such as fibroblasts and smooth muscle cells, are more likely to maintain an oblique orientation with respect to the main stretching direction. Conversely, rounder cells, such as those of epithelial or endothelial origin, are more likely to switch to a perpendicular or parallel orientation on soft substrates.
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Affiliation(s)
- Annachiara Colombi
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
| | - Luigi Preziosi
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy.
| | - Marco Scianna
- Department of Mathematical Sciences "G.L. Lagrange", Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129, Turin, Italy
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3
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Loy N, Preziosi L. A Statistical Mechanics Approach to Describe Cell Reorientation Under Stretch. Bull Math Biol 2023; 85:60. [PMID: 37249663 DOI: 10.1007/s11538-023-01161-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/25/2023] [Indexed: 05/31/2023]
Abstract
Experiments show that when a monolayer of cells cultured on an elastic substratum is subject to a cyclic stretch, cells tend to reorient either perpendicularly or at an oblique angle with respect to the main stretching direction. Due to stochastic effects, however, the distribution of angles achieved by the cells is broader and, experimentally, histograms over the interval [Formula: see text] are usually reported. Here we will determine the evolution and the stationary state of probability density functions describing the statistical distribution of the orientations of the cells using Fokker-Planck equations derived from microscopic rules for describing the reorientation process of the cell. As a first attempt, we shall use a stochastic differential equation related to a very general elastic energy that the cell tries to minimize and, we will show that the results of the time integration and of the stationary state of the related forward Fokker-Planck equation compare very well with experimental results obtained by different researchers. Then, in order to model more accurately the microscopic process of cell reorientation and to shed light on the mechanisms performed by cells that are subject to cyclic stretch, we consider discrete in time random processes that allow to recover Fokker-Planck equations through classical tools of kinetic theory. In particular, we shall introduce a model of reorientation as a function of the rotation angle as a result of an optimal control problem. Also in this latter case the results match very well with experiments.
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Affiliation(s)
- N Loy
- Politecnico di Torino, Torino, Italy.
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4
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Moriel A, Wolfenson H, Bouchbinder E. Characteristic energy scales of active fluctuations in adherent cells. BIOPHYSICAL REPORTS 2023; 3:100099. [PMID: 36698752 PMCID: PMC9867956 DOI: 10.1016/j.bpr.2022.100099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Cell-matrix and cell-cell adhesion play important roles in a wide variety of physiological processes, from the single-cell level to the large scale, multicellular organization of tissues. Cells actively apply forces to their environment, either extracellular matrix or neighboring cells, as well as sense its biophysical properties. The fluctuations associated with these active processes occur on an energy scale much larger than that of ordinary thermal equilibrium fluctuations, yet their statistical properties and characteristic scales are not fully understood. Here, we compare measurements of the energy scale of active cellular fluctuations-an effective cellular temperature-in four different biophysical settings, involving both single-cell and cell-aggregate experiments under various control conditions, different cell types, and various biophysical observables. The results indicate that a similar energy scale of active fluctuations might characterize the same cell type in different settings, though it may vary among different cell types, being approximately six to eight orders of magnitude larger than the ordinary thermal energy at room temperature. These findings call for extracting the energy scale of active fluctuations over a broader range of cell types, experimental settings, and biophysical observables and for understanding the biophysical origin and significance of such cellular energy scales.
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Affiliation(s)
- Avraham Moriel
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot, Israel
| | - Haguy Wolfenson
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Eran Bouchbinder
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot, Israel
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5
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Das S, Ippolito A, McGarry P, Deshpande VS. Cell reorientation on a cyclically strained substrate. PNAS NEXUS 2022; 1:pgac199. [PMID: 36712366 PMCID: PMC9802216 DOI: 10.1093/pnasnexus/pgac199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 09/17/2022] [Indexed: 06/18/2023]
Abstract
Cyclic strain avoidance, the phenomenon of cell and cytoskeleton alignment perpendicular to the direction of cyclic strain of the underlying 2D substrate, is an important characteristic of the adherent cell organization. This alignment has typically been attributed to the stress-fiber reorganization although observations clearly show that stress-fiber reorganization under cyclic loading is closely coupled to cell morphology and reorientation of the cells. Here, we develop a statistical mechanics framework that couples the cytoskeletal stress-fiber organization with cell morphology under imposed cyclic straining and make quantitative comparisons with observations. The framework accurately predicts that cyclic strain avoidance stems primarily from cell reorientation away from the cyclic straining rather than cytoskeletal reorganization within the cell. The reorientation of the cell is a consequence of the cell lowering its free energy by largely avoiding the imposed cyclic straining. Furthermore, we investigate the kinetics of the cyclic strain avoidance mechanism and demonstrate that it emerges primarily due to the rigid body rotation of the cell rather than via a trajectory involving cell straining. Our results provide clear physical insights into the coupled dynamics of cell morphology and stress-fibers, which ultimately leads to cellular organization in cyclically strained tissues.
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Affiliation(s)
- Shuvrangsu Das
- Department of Engineering, Cambridge University, Trumpington St, Cambridge CB2 1PZ, UK
| | - Alberto Ippolito
- Department of Engineering, Cambridge University, Trumpington St, Cambridge CB2 1PZ, UK
| | - Patrick McGarry
- Department of Mechanical and Biomedical Engineering, National University of Ireland, University Road, Galway H91 CF50, Ireland
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6
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Moriel A, Livne A, Bouchbinder E. Cellular orientational fluctuations, rotational diffusion and nematic order under periodic driving. SOFT MATTER 2022; 18:7091-7102. [PMID: 36043855 DOI: 10.1039/d2sm00611a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The ability of living cells to sense the physical properties of their microenvironment and to respond to dynamic forces acting on them plays a central role in regulating their structure, function and fate. Of particular importance is the cellular sensitivity and response to periodic driving forces in noisy environments, encountered in vital physiological conditions such as heart beating, blood vessel pulsation and breathing. Here, we first test and validate two predictions of a mean-field theory of cellular reorientation under periodic driving, which combines the minimization of cellular anisotropic elastic energy with active remodeling forces. We then extend the mean-field theory to include uncorrelated, additive nonequilibrium fluctuations, and show that the theory quantitatively agrees with the experimentally observed stationary probability distributions of the cell body orientation, under a range of biaxial periodic driving forces. The fluctuations theory allows the extraction of the dimensionless active noise amplitude of various cell types, and consequently their rotational diffusion coefficient. We then focus on intra-cellular nematic order, i.e. on orientational fluctuations of actin stress fibers around the cell body orientation, and show experimentally that intra-cellular nematic order increases with both the magnitude of the driving forces and the biaxiality strain ratio. These results are semi-quantitatively explained by applying the same cell body fluctuations theory to orientationally correlated actin stress fiber domains. Finally, an estimate of the energy scale of cellular orientational fluctuations for one cell type is shown to be about six order of magnitude larger than the thermal energy at room temperature. The implications of our findings, which make the quantitative analysis of cell mechanosensitivity more accessible, are discussed.
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Affiliation(s)
- Avraham Moriel
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot 7610001, Israel.
| | - Ariel Livne
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
- Diptera.ai, PO Box 39047, Jerusalem 9139002, Israel
| | - Eran Bouchbinder
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot 7610001, Israel.
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7
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Mukhopadhyay D, De R. Growth kinetics and power laws indicate distinct mechanisms of cell-cell interactions in the aggregation process. Biophys J 2022; 121:481-490. [PMID: 34968426 PMCID: PMC8822615 DOI: 10.1016/j.bpj.2021.12.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 11/20/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023] Open
Abstract
Cellular aggregation is a complex process orchestrated by various kinds of interactions depending on the environment. Different interactions give rise to different pathways of cellular rearrangement and the development of specialized tissues. To distinguish the underlying mechanisms, in this theoretical work, we investigate the spontaneous emergence of tissue patterns from an ensemble of single cells on a substrate following three leading pathways of cell-cell interactions, namely, direct cell adhesion contacts, matrix-mediated mechanical interaction, and chemical signaling. Our analysis shows that the growth kinetics of the aggregation process are distinctly different for each pathway and bear the signature of the specific cell-cell interactions. Interestingly, we find that the average domain size and the mass of the clusters exhibit a power law growth in time under certain interaction mechanisms hitherto unexplored. Further, as observed in experiments, the cluster size distribution can be characterized by stretched exponential functions showing distinct cellular organization processes.
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Affiliation(s)
- Debangana Mukhopadhyay
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Rumi De
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India.
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8
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Wang C, Li S, Ademiloye AS, Nithiarasu P. Biomechanics of cells and subcellular components: A comprehensive review of computational models and applications. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3520. [PMID: 34390323 DOI: 10.1002/cnm.3520] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Cells are a fundamental structural, functional and biological unit for all living organisms. Up till now, considerable efforts have been made to study the responses of single cells and subcellular components to an external load, and understand the biophysics underlying cell rheology, mechanotransduction and cell functions using experimental and in silico approaches. In the last decade, computational simulation has become increasingly attractive due to its critical role in interpreting experimental data, analysing complex cellular/subcellular structures, facilitating diagnostic designs and therapeutic techniques, and developing biomimetic materials. Despite the significant progress, developing comprehensive and accurate models of living cells remains a grand challenge in the 21st century. To understand current state of the art, this review summarises and classifies the vast array of computational biomechanical models for cells. The article covers the cellular components at multi-spatial levels, that is, protein polymers, subcellular components, whole cells and the systems with scale beyond a cell. In addition to the comprehensive review of the topic, this article also provides new insights into the future prospects of developing integrated, active and high-fidelity cell models that are multiscale, multi-physics and multi-disciplinary in nature. This review will be beneficial for the researchers in modelling the biomechanics of subcellular components, cells and multiple cell systems and understanding the cell functions and biological processes from the perspective of cell mechanics.
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Affiliation(s)
- Chengyuan Wang
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, UK
| | - Si Li
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, UK
| | - Adesola S Ademiloye
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, UK
| | - Perumal Nithiarasu
- Zienkiewicz Centre for Computational Engineering, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, UK
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9
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Huycke TR, Miller BM, Gill HK, Nerurkar NL, Sprinzak D, Mahadevan L, Tabin CJ. Genetic and Mechanical Regulation of Intestinal Smooth Muscle Development. Cell 2020; 179:90-105.e21. [PMID: 31539501 DOI: 10.1016/j.cell.2019.08.041] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 05/31/2019] [Accepted: 08/22/2019] [Indexed: 11/30/2022]
Abstract
The gastrointestinal tract is enveloped by concentric and orthogonally aligned layers of smooth muscle; however, an understanding of the mechanisms by which these muscles become patterned and aligned in the embryo has been lacking. We find that Hedgehog acts through Bmp to delineate the position of the circumferentially oriented inner muscle layer, whereas localized Bmp inhibition is critical for allowing formation of the later-forming, longitudinally oriented outer layer. Because the layers form at different developmental stages, the muscle cells are exposed to unique mechanical stimuli that direct their alignments. Differential growth within the early gut tube generates residual strains that orient the first layer circumferentially, and when formed, the spontaneous contractions of this layer align the second layer longitudinally. Our data link morphogen-based patterning to mechanically controlled smooth muscle cell alignment and provide a mechanistic context for potentially understanding smooth muscle organization in a wide variety of tubular organs.
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Affiliation(s)
- Tyler R Huycke
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Bess M Miller
- Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Hasreet K Gill
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Nandan L Nerurkar
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - David Sprinzak
- Department of Biochemistry and Molecular Biology, George S. Wise Faculty of Life Science, Tel Aviv University, Tel Aviv, Israel
| | - L Mahadevan
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Department of Physics, Harvard University, Cambridge, MA 02138, USA; Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, MA 02138, USA
| | - Clifford J Tabin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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10
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Molina JJ, Yamamoto R. Modeling the mechanosensitivity of fast-crawling cells on cyclically stretched substrates. SOFT MATTER 2019; 15:683-698. [PMID: 30623962 DOI: 10.1039/c8sm01903g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The mechanosensitivity of cells, which determines how they are able to respond to mechanical signals, is crucial for the functioning of biological systems. Experimentally, this is investigated by studying the reorientation of cells on cyclically stretched substrates. The reorientation depends on the type of cell and on the stretching protocol, but the mechanisms responsible for the response are still not completely understood. Here, we introduce a computational model for fast crawling cells on cyclically stretched substrates that accounts for the sub-cellular elements responsible for cell shape and motility. This includes the dynamics of the cell membrane, the actin cytoskeleton, and the focal adhesions with the stretching substrate. These processes evolve over characteristic time scales that can vary by orders of magnitude and naturally give rise to the frequency dependent reorientation observed experimentally. Depending on which processes are being probed by the stretching and on the type of coupling with the substrate, our simulations predict either no reorientation, a bi-stability in the parallel and perpendicular directions, or a complete reorientation in either the parallel or perpendicular direction. In particular, we show that an asymmetry in the adhesion dynamics during the loading and unloading phases of the stretching, whether it comes from the response of the cell itself or from the precise stretching protocol, can be used to selectively align the cells. Our results provide further evidence for the importance of focal adhesion dynamics in determining the mechanosensitive response of cells, as well as a way to interpret recent experiments.
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Affiliation(s)
- John J Molina
- Department of Chemical Engineering, Kyoto University, Kyoto, Japan.
| | - Ryoichi Yamamoto
- Department of Chemical Engineering, Kyoto University, Kyoto, Japan. and Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
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11
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Chagnon-Lessard S, Godin M, Pelling AE. Time dependence of cellular responses to dynamic and complex strain fields. Integr Biol (Camb) 2019; 11:4-15. [PMID: 30778578 DOI: 10.1093/intbio/zyy002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/08/2018] [Indexed: 11/13/2022]
Abstract
Exposing cells to an unconventional sequence of physical cues can reveal subtleties of cellular sensing and response mechanisms. We investigated the mechanoresponse of cyclically stretched fibroblasts under a spatially non-uniform strain field which was subjected to repeated changes in stretching directions over 55 h. A polydimethylsiloxane microfluidic stretcher array optimized for complex staining procedures and imaging was developed to generate biologically relevant strain and strain gradient amplitudes. We demonstrated that cells can successfully reorient themselves repeatedly, as the main cyclical stretching direction is consecutively switched between two perpendicular directions every 11 h. Importantly, from one reorientation to the next, the extent to which cells reorient themselves perpendicularly to the local strain direction progressively decreases, while their tendency to align perpendicularly to the strain gradient direction increases. We demonstrate that these results are consistent with our finding that cellular responses to strains and strain gradients occur on two distinct time scales, the latter being slower. Overall, our results reveal the absence of major irreversible cellular changes that compromise the ability to sense and reorient to changing strain directions under the conditions of this experiment. On the other hand, we show how the history of strain field dynamics can influence the cellular realignment behavior, due to the interplay of complex time-dependent responses.
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Affiliation(s)
| | - Michel Godin
- Department of Physics, STEM Building 150 Louis Pasteur, Ottawa, Canada.,Department of Mechanical Engineering, Site Building, 800 King Edward Avenue, University of Ottawa, ON, Canada.,Ottawa-Carleton Institute for Biomedical Engineering, Ottawa, ON, Canada
| | - Andrew E Pelling
- Department of Physics, STEM Building 150 Louis Pasteur, Ottawa, Canada.,Department of Biology, Gendron Hall, 30 Marie Curie, University of Ottawa, Ottawa, ON, Canada.,Institute for Science Society and Policy, Simard Hall, 60 University, University of Ottawa, Ottawa, ON, Canada.,SymbioticA, School of Anatomy, Physiology and Human Biology, University of Western Australia, Perth, WA, Australia
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12
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Bernheim-Groswasser A, Gov NS, Safran SA, Tzlil S. Living Matter: Mesoscopic Active Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707028. [PMID: 30256463 DOI: 10.1002/adma.201707028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/27/2018] [Indexed: 06/08/2023]
Abstract
An introduction to the physical properties of living active matter at the mesoscopic scale (tens of nanometers to micrometers) and their unique features compared with "dead," nonactive matter is presented. This field of research is increasingly denoted as "biological physics" where physics includes chemical physics, soft matter physics, hydrodynamics, mechanics, and the related engineering sciences. The focus is on the emergent properties of these systems and their collective behavior, which results in active self-organization and how they relate to cellular-level biological function. These include locomotion (cell motility and migration) forces that give rise to cell division, the growth and form of cellular assemblies in development, the beating of heart cells, and the effects of mechanical perturbations such as shear flow (in the bloodstream) or adhesion to other cells or tissues. An introduction to the fundamental concepts and theory with selected experimental examples related to the authors' own research is presented, including red-blood-cell membrane fluctuations, motion of the nucleus within an egg cell, self-contracting acto-myosin gels, and structure and beating of heart cells (cardiomyocytes), including how they can be driven by an oscillating, mechanical probe.
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Affiliation(s)
- Anne Bernheim-Groswasser
- Department of Chemical Engineering and Ilse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Nir S Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Samuel A Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shelly Tzlil
- Department of Mechanical Engineering, Technion, Haifa, 3200003, Israel
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13
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Chagnon-Lessard S, Jean-Ruel H, Godin M, Pelling AE. Cellular orientation is guided by strain gradients. Integr Biol (Camb) 2018; 9:607-618. [PMID: 28534911 DOI: 10.1039/c7ib00019g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The strain-induced reorientation response of cyclically stretched cells has been well characterized in uniform strain fields. In the present study, we comprehensively analyse the behaviour of human fibroblasts subjected to a highly non-uniform strain field within a polymethylsiloxane microdevice. Our results indicate that the strain gradient amplitude and direction regulate cell reorientation through a coordinated gradient avoidance response. We provide critical evidence that strain gradient is a key physical cue that can guide cell organization. Specifically, our work suggests that cells are able to pinpoint the location under the cell of multiple physical cues and integrate this information (strain and strain gradient amplitudes and directions), resulting in a coordinated response. To gain insight into the underlying mechanosensing processes, we studied focal adhesion reorganization and the effect of modulating myosin-II contractility. The extracted focal adhesion orientation distributions are similar to those obtained for the cell bodies, and their density is increased by the presence of stretching forces. Moreover, it was found that the myosin-II activity promoter calyculin-A has little effect on the cellular response, while the inhibitor blebbistatin suppresses cell and focal adhesion alignment and reduces focal adhesion density. These results confirm that similar internal structures involved in sensing and responding to strain direction and amplitude are also key players in strain gradient mechanosensing and avoidance.
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Affiliation(s)
- Sophie Chagnon-Lessard
- Department of Physics, Center for Interdisciplinary Nanophysics, University of Ottawa, 598 King Edward, Ottawa, ON K1N 6N5, Canada.
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14
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Xu GK, Feng XQ, Gao H. Orientations of Cells on Compliant Substrates under Biaxial Stretches: A Theoretical Study. Biophys J 2018; 114:701-710. [PMID: 29414715 PMCID: PMC5985023 DOI: 10.1016/j.bpj.2017.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/25/2017] [Accepted: 12/05/2017] [Indexed: 10/24/2022] Open
Abstract
Mechanical cues from the microenvironments play a regulating role in many physiological and pathological processes, such as stem cell differentiation and cancer cell metastasis. Experiments showed that cells adhered on a compliant substrate may change orientation with an externally applied strain in the substrate. By accounting for actin polymerization, actin retrograde flow, and integrin binding dynamics, here we develop a mechanism-based tensegrity model to study the orientations of polarized cells on a compliant substrate under biaxial stretches. We show that the cell can actively regulate its mechanical state by generating different traction force levels along its polarized direction. Under static or ultralow-frequency cyclic stretches, stretching a softer substrate leads to a higher increase in the traction force and induces a narrower distribution of cell alignment. Compared to static loadings, high-frequency cyclic loadings have a more significant influence on cell reorientation on a stiff substrate. In addition, the width of the cellular angular distribution scales inversely with the stretch amplitude under both static and cyclic stretches. Our results are in agreement with a wide range of experimental observations, and provide fundamental insights into the functioning of cellular mechanosensing systems.
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Affiliation(s)
- Guang-Kui Xu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, China.
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing, China
| | - Huajian Gao
- School of Engineering, Brown University, Providence, Rhode Island
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15
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Cheng B, Lin M, Huang G, Li Y, Ji B, Genin GM, Deshpande VS, Lu TJ, Xu F. Cellular mechanosensing of the biophysical microenvironment: A review of mathematical models of biophysical regulation of cell responses. Phys Life Rev 2017; 22-23:88-119. [PMID: 28688729 PMCID: PMC5712490 DOI: 10.1016/j.plrev.2017.06.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 12/11/2022]
Abstract
Cells in vivo reside within complex microenvironments composed of both biochemical and biophysical cues. The dynamic feedback between cells and their microenvironments hinges upon biophysical cues that regulate critical cellular behaviors. Understanding this regulation from sensing to reaction to feedback is therefore critical, and a large effort is afoot to identify and mathematically model the fundamental mechanobiological mechanisms underlying this regulation. This review provides a critical perspective on recent progress in mathematical models for the responses of cells to the biophysical cues in their microenvironments, including dynamic strain, osmotic shock, fluid shear stress, mechanical force, matrix rigidity, porosity, and matrix shape. The review highlights key successes and failings of existing models, and discusses future opportunities and challenges in the field.
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Affiliation(s)
- Bo Cheng
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Guoyou Huang
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Yuhui Li
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Baohua Ji
- Biomechanics and Biomaterials Laboratory, Department of Applied Mechanics, Beijing Institute of Technology, Beijing, China
| | - Guy M Genin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China; Department of Mechanical Engineering & Materials Science, and NSF Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis 63130, MO, USA
| | - Vikram S Deshpande
- Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom
| | - Tian Jian Lu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China
| | - Feng Xu
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, PR China; Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, PR China.
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16
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Cancer Cell Mechanics. PHYSICAL SCIENCES AND ENGINEERING ADVANCES IN LIFE SCIENCES AND ONCOLOGY 2016. [DOI: 10.1007/978-3-319-17930-8_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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17
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Sears C, Kaunas R. The many ways adherent cells respond to applied stretch. J Biomech 2015; 49:1347-1354. [PMID: 26515245 DOI: 10.1016/j.jbiomech.2015.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 10/05/2015] [Accepted: 10/10/2015] [Indexed: 10/24/2022]
Abstract
Cells in various tissues are subjected to mechanical stress and strain that have profound effects on cell architecture and function. The specific response of the cell to applied strain depends on multiple factors, including cell contractility, spatial and temporal strain pattern, and substrate dimensionality and rigidity. Recent work has demonstrated that the cell response to applied strain depends on a complex combination of these factors, but the way these factors interact to elicit a specific response is not intuitive. We submit that an understanding of the integrated response of a cell to these factors will provide new insight into mechanobiology and contribute to the effective design of deformable engineered scaffolds meant to provide appropriate mechanical cues to the resident cells.
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Affiliation(s)
- Candice Sears
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120, USA
| | - Roland Kaunas
- Department of Biomedical Engineering, Texas A&M University, College Station, TX 77843-3120, USA.
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18
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Chen B, Chen X, Gao H. Dynamics of Cellular Reorientation on a Substrate under Biaxial Cyclic Stretches. NANO LETTERS 2015; 15:5525-5529. [PMID: 26108295 DOI: 10.1021/acs.nanolett.5b02095] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
It is widely known that mechanical signals such as force, geometry, and substrate elasticity can be utilized by cells to regulate their structures, functions, and behaviors. However, the exact nature of the underlying mechanisms of cellular mechanosensing is unclear. Recently, extensive experiments on cellular reorientation dynamics on a substrate under biaxial cyclic stretches were performed, and the measured behaviors were found to be incompatible with existing theories. Here, we show that a theoretical model based on both tensile and shearing forces on focal adhesions (FAs) is capable of reproducing the new experimental data. This work provides important mechanistic insights into how behaviors of FAs can strongly affect cellular reorientation dynamics on a cyclically stretched substrate.
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Affiliation(s)
- Bin Chen
- †Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, P. R. China
| | - Xiaofeng Chen
- †Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, P. R. China
| | - Huajian Gao
- ‡School of Engineering, Brown University, Providence, Rhode Island 02912, United States
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19
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Ben-Yaakov D, Golkov R, Shokef Y, Safran SA. Response of adherent cells to mechanical perturbations of the surrounding matrix. SOFT MATTER 2015; 11:1412-1424. [PMID: 25604950 DOI: 10.1039/c4sm01817f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a generic and unified theory to explain how cells respond to perturbations of their mechanical environment such as the presence of neighboring cells, slowly applied stretch, or gradients of matrix rigidity. Motivated by experiments, we calculate the local balance of forces that give rise to a tendency for the cell to locally move or reorient, with a focus on the contribution of feedback and homeostasis to cell contractility (manifested by a fixed displacement, strain or stress) that acts on the adhesions at the cell boundary. These forces can be either reinforced or diminished by elastic stresses due to mechanical perturbations of the matrix. Our model predicts these changes and how their balance with local protrusive forces that act on the cell's leading edge either increase or decrease the tendency of the cell to locally move (toward neighboring cells or rigidity gradients) or reorient (in the direction of slowly applied stretch or rigidity gradients).
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Affiliation(s)
- Dan Ben-Yaakov
- Dept. Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel.
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20
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He LH. Thickness-dependent attraction or repulsion between defects on a thin elastic film. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:062409. [PMID: 25019796 DOI: 10.1103/physreve.89.062409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Indexed: 06/03/2023]
Abstract
We examine elastic interaction between two defects on one side or two sides of an isotropic thin film. We show that the tangential and normal forces contribute to the interaction in a coupled manner. Our finding is that the attraction or repulsion between two defects exhibiting twofold symmetry is dependent on the film thickness. The result is of particular importance for probing elastic interaction between adherent cells which have been commonly treated as twofold surface defects.
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Affiliation(s)
- L H He
- CAS Key Laboratory of Mechanical Behavior and Design of Materials & Institute of Solid State Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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21
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Abstract
Mechanical cues from the extracellular microenvironment play a central role in regulating the structure, function and fate of living cells. Nevertheless, the precise nature of the mechanisms and processes underlying this crucial cellular mechanosensitivity remains a fundamental open problem. Here we provide a novel framework for addressing cellular sensitivity and response to external forces by experimentally and theoretically studying one of its most striking manifestations – cell reorientation to a uniform angle in response to cyclic stretching of the underlying substrate. We first show that existing approaches are incompatible with our extensive measurements of cell reorientation. We then propose a fundamentally new theory that shows that dissipative relaxation of the cell’s passively-stored, two-dimensional, elastic energy to its minimum actively drives the reorientation process. Our theory is in excellent quantitative agreement with the complete temporal reorientation dynamics of individual cells, measured over a wide range of experimental conditions, thus elucidating a basic aspect of mechanosensitivity.
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22
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Elson EL, Genin GM. The role of mechanics in actin stress fiber kinetics. Exp Cell Res 2013; 319:2490-500. [PMID: 23906923 DOI: 10.1016/j.yexcr.2013.06.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 06/24/2013] [Indexed: 01/11/2023]
Abstract
The dynamic responses of actin stress fibers within a cell's cytoskeleton are central to the development and maintenance of healthy tissues and organs. Disturbances to these underlie a broad range of pathologies. Because of the importance of these responses, extensive experiments have been conducted in vitro to characterize actin cytoskeleton dynamics of cells cultured upon two-dimensional substrata, and the first experiments have been conducted for cells within three-dimensional tissue models. Three mathematical models exist for predicting the dynamic behaviors observed. Surprisingly, despite differing viewpoints on how actin stress fibers are stabilized or destabilized, all of these models are predictive of a broad range of available experimental data. Coarsely, the models of Kaunas and co-workers adopt a strategy whereby mechanical stretch can hasten the depolymerization actin stress fibers that turn over constantly, while the models of Desphande and co-workers adopt a strategy whereby mechanical stress is required to activate the formation of stress fibers and subsequently stabilize them. In three-dimensional culture, elements of both approaches appear necessary to predict observed phenomena, as embodied by the model of Lee et al. After providing a critical review of existing models, we propose lines of experimentation that might be able to test the different principles underlying their kinetic laws.
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Affiliation(s)
- E L Elson
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, United States; Department of Mechanical Engineering and Materials Science, Washington University, St. Louis, MO 63130, United States.
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23
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Qian J, Liu H, Lin Y, Chen W, Gao H. A mechanochemical model of cell reorientation on substrates under cyclic stretch. PLoS One 2013; 8:e65864. [PMID: 23762444 PMCID: PMC3675090 DOI: 10.1371/journal.pone.0065864] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/29/2013] [Indexed: 01/09/2023] Open
Abstract
We report a theoretical study on the cyclic stretch-induced reorientation of spindle-shaped cells. Specifically, by taking into account the evolution of sub-cellular structures like the contractile stress fibers and adhesive receptor-ligand clusters, we develop a mechanochemical model to describe the dynamics of cell realignment in response to cyclically stretched substrates. Our main hypothesis is that cells tend to orient in the direction where the formation of stress fibers is energetically most favorable. We show that, when subjected to cyclic stretch, the final alignment of cells reflects the competition between the elevated force within stress fibers that accelerates their disassembly and the disruption of cell-substrate adhesion as well, and an effectively increased substrate rigidity that promotes more stable focal adhesions. Our model predictions are consistent with various observations like the substrate rigidity dependent formation of stable adhesions and the stretching frequency, as well as stretching amplitude, dependence of cell realignment. This theory also provides a simple explanation on the regulation of protein Rho in the formation of stretch-induced stress fibers in cells.
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Affiliation(s)
- Jin Qian
- Department of Engineering Mechanics, Soft Matter Research Center, Zhejiang University, Hangzhou, Zhejiang, China
| | - Haipei Liu
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Yuan Lin
- Department of Mechanical Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Weiqiu Chen
- Department of Engineering Mechanics, Soft Matter Research Center, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huajian Gao
- School of Engineering, Brown University, Providence, Rhode Island, United States of America
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24
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Leccia E, Batonnet-Pichon S, Tarze A, Bailleux V, Doucet J, Pelloux M, Delort F, Pizon V, Vicart P, Briki F. Cyclic stretch reveals a mechanical role for intermediate filaments in a desminopathic cell model. Phys Biol 2012; 10:016001. [PMID: 23234811 DOI: 10.1088/1478-3975/10/1/016001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Mechanics is now recognized as crucial in cell function. To date, the mechanical properties of cells have been inferred from experiments which investigate the roles of actin and microtubules ignoring the intermediate filaments (IFs) contribution. Here, we analyse myoblasts behaviour in the context of myofibrillar myopathy resulting from p.D399Y desmin mutation which disorganizes the desmin IF network in muscle cells. We compare the response of myoblasts expressing either mutated or wild-type desmin to cyclic stretch. Cells are cultivated on supports submitted to periodic uniaxial stretch of 20% elongation amplitude and 0.3 Hz frequency. We show that during stretching cycles, cells expressing mutated desmin reduce their mean amplitude both for the elongation and spreading area compared to those expressing wild-type desmin. Even more unexpected, the reorientation angles are altered in the presence of p.D399Y desmin. Yet, at rest, the whole set of those parameters are similar for the two cell populations. Thus, we demonstrate that IFs affect the mechanical properties and the dynamics of cell reorientation. Since these processes are known due to actin cytoskeleton, these results suggest the IFs implication in mechanics signal transduction. Further studies may lead to better understanding of their contribution to this process.
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Affiliation(s)
- E Leccia
- Université Paris Sud, Paris 11, Laboratoire de Physique des solides, Bat 510-91405 Orsay Cedex, France
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25
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Dado D, Sagi M, Levenberg S, Zemel A. Mechanical control of stem cell differentiation. Regen Med 2012; 7:101-16. [DOI: 10.2217/rme.11.99] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Numerous studies have focused on identifying the chemical and biological factors that govern the differentiation of stem cells; however, recent research has shown that mechanical cues may play an equally important role. Mechanical forces such as shear stresses and tensile loads, as well as the rigidity and topography of the extracellular matrix were shown to induce significant changes in the morphology and fate of stem cells. We survey experimental studies that focused on the response of stem cells to mechanical and geometrical properties of their environment and discuss the mechanical mechanisms that accompany their response including the remodeling of the cytoskeleton and determination of cell and nucleus size and shape.
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Affiliation(s)
- Dekel Dado
- Biomedical Engineering, Technion, Haifa, 32000, Israel
| | - Maayan Sagi
- Institute of Dental Sciences & the Fritz Haber Research Center, Hebrew-University, Hadassah Medical Center, Jerusalem, 91120, Israel
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26
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Faust U, Hampe N, Rubner W, Kirchgeßner N, Safran S, Hoffmann B, Merkel R. Cyclic stress at mHz frequencies aligns fibroblasts in direction of zero strain. PLoS One 2011; 6:e28963. [PMID: 22194961 PMCID: PMC3241701 DOI: 10.1371/journal.pone.0028963] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 11/18/2011] [Indexed: 01/16/2023] Open
Abstract
Recognition of external mechanical signals is vital for mammalian cells. Cyclic stretch, e.g. around blood vessels, is one such signal that induces cell reorientation from parallel to almost perpendicular to the direction of stretch. Here, we present quantitative analyses of both, cell and cytoskeletal reorientation of umbilical cord fibroblasts. Cyclic strain of preset amplitudes was applied at mHz frequencies. Elastomeric chambers were specifically designed and characterized to distinguish between zero strain and minimal stress directions and to allow accurate theoretical modeling. Reorientation was only induced when the applied stretch exceeded a specific amplitude, suggesting a non-linear response. However, on very soft substrates no mechanoresponse occurs even for high strain. For all stretch amplitudes, the angular distributions of reoriented cells are in very good agreement with a theory modeling stretched cells as active force dipoles. Cyclic stretch increases the number of stress fibers and the coupling to adhesions. We show that changes in cell shape follow cytoskeletal reorientation with a significant temporal delay. Our data identify the importance of environmental stiffness for cell reorientation, here in direction of zero strain. These in vitro experiments on cultured cells argue for the necessity of rather stiff environmental conditions to induce cellular reorientation in mammalian tissues.
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Affiliation(s)
- Uta Faust
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Nico Hampe
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Wolfgang Rubner
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Norbert Kirchgeßner
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Sam Safran
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, Israel
| | - Bernd Hoffmann
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
- * E-mail:
| | - Rudolf Merkel
- Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
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27
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Abstract
Recent discoveries have established that mechanical properties of the cellular environment such as its rigidity, geometry, and external stresses play an important role in determining the cellular function and fate. Mechanical properties have been shown to influence cell shape and orientation, regulate cell proliferation and differentiation, and even govern the development and organization of tissues. In recent years, many theoretical and experimental investigations have been carried out to elucidate the mechanisms and consequences of the mechanosensitivity of cells. In this review, we discuss recent theoretical concepts and approaches that explain and predict cell mechanosensitivity. We focus on the interplay of active and passive processes that govern cell-cell and cell-matrix interactions and discuss the role of this interplay in the processes of cell adhesion, regulation of cytoskeleton mechanics and the response of cells to applied mechanical stresses.
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Affiliation(s)
- Rumi De
- Indian institute of Science Education and Research, Kolkata, Mohanpur 741252, Nadia, West Bengal, India
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