1
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Wang X, Jenner AL, Salomone R, Warne DJ, Drovandi C. Calibration of agent based models for monophasic and biphasic tumour growth using approximate Bayesian computation. J Math Biol 2024; 88:28. [PMID: 38358410 PMCID: PMC10869399 DOI: 10.1007/s00285-024-02045-4] [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: 06/28/2023] [Revised: 10/25/2023] [Accepted: 12/27/2023] [Indexed: 02/16/2024]
Abstract
Agent-based models (ABMs) are readily used to capture the stochasticity in tumour evolution; however, these models are often challenging to validate with experimental measurements due to model complexity. The Voronoi cell-based model (VCBM) is an off-lattice agent-based model that captures individual cell shapes using a Voronoi tessellation and mimics the evolution of cancer cell proliferation and movement. Evidence suggests tumours can exhibit biphasic growth in vivo. To account for this phenomena, we extend the VCBM to capture the existence of two distinct growth phases. Prior work primarily focused on point estimation for the parameters without consideration of estimating uncertainty. In this paper, approximate Bayesian computation is employed to calibrate the model to in vivo measurements of breast, ovarian and pancreatic cancer. Our approach involves estimating the distribution of parameters that govern cancer cell proliferation and recovering outputs that match the experimental data. Our results show that the VCBM, and its biphasic extension, provides insight into tumour growth and quantifies uncertainty in the switching time between the two phases of the biphasic growth model. We find this approach enables precise estimates for the time taken for a daughter cell to become a mature cell. This allows us to propose future refinements to the model to improve accuracy, whilst also making conclusions about the differences in cancer cell characteristics.
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Affiliation(s)
- Xiaoyu Wang
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
- Centre for Data Science, Queensland University of Technology, Brisbane, QLD, Australia.
| | - Adrianne L Jenner
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Centre for Data Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Robert Salomone
- Centre for Data Science, Queensland University of Technology, Brisbane, QLD, Australia
- School of Computer Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - David J Warne
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Centre for Data Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Christopher Drovandi
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Centre for Data Science, Queensland University of Technology, Brisbane, QLD, Australia
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2
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Das R, Sinha S, Li X, Kirkpatrick TR, Thirumalai D. Free volume theory explains the unusual behavior of viscosity in a non-confluent tissue during morphogenesis. eLife 2024; 12:RP87966. [PMID: 38241331 PMCID: PMC10945604 DOI: 10.7554/elife.87966] [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] [Indexed: 01/21/2024] Open
Abstract
A recent experiment on zebrafish blastoderm morphogenesis showed that the viscosity (η) of a non-confluent embryonic tissue grows sharply until a critical cell packing fraction (ϕS). The increase in η up to ϕS is similar to the behavior observed in several glass-forming materials, which suggests that the cell dynamics is sluggish or glass-like. Surprisingly, η is a constant above ϕS. To determine the mechanism of this unusual dependence of η on ϕ, we performed extensive simulations using an agent-based model of a dense non-confluent two-dimensional tissue. We show that polydispersity in the cell size, and the propensity of the cells to deform, results in the saturation of the available free area per cell beyond a critical packing fraction. Saturation in the free space not only explains the viscosity plateau above ϕS but also provides a relationship between equilibrium geometrical packing to the dramatic increase in the relaxation dynamics.
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Affiliation(s)
- Rajsekhar Das
- Department of Chemistry, University of Texas at AustinAustinUnited States
| | - Sumit Sinha
- Department of Physics, University of Texas at AustinAustinUnited States
| | - Xin Li
- Department of Chemistry, University of Texas at AustinAustinUnited States
| | - TR Kirkpatrick
- Institute for Physical Science and Technology, University of MarylandCollege ParkUnited States
| | - D Thirumalai
- Department of Chemistry, University of Texas at AustinAustinUnited States
- Department of Physics, University of Texas at AustinAustinUnited States
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3
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Su Z, Almo SC, Wu Y. Computational simulations of bispecific T cell engagers by a multiscale model. Biophys J 2024; 123:235-247. [PMID: 38102828 PMCID: PMC10808035 DOI: 10.1016/j.bpj.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 11/04/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023] Open
Abstract
The use of bispecific antibodies as T cell engagers can bypass the normal T cell receptor-major histocompatibility class interaction, redirect the cytotoxic activity of T cells, and lead to highly efficient tumor cell killing. However, this immunotherapy also causes significant on-target off-tumor toxicologic effects, especially when it is used to treat solid tumors. To avoid these adverse events, it is necessary to understand the fundamental mechanisms involved in the physical process of T cell engagement. We developed a multiscale computational framework to reach this goal. The framework combines simulations on the intercellular and multicellular levels. On the intercellular level, we simulated the spatial-temporal dynamics of three-body interactions among bispecific antibodies, CD3 and tumor-associated antigens (TAAs). The derived number of intercellular bonds formed between CD3 and TAAs was further transferred to the multicellular simulations as the input parameter of adhesive density between cells. Through the simulations under various molecular and cellular conditions, we were able to gain new insights into how to adopt the most appropriate strategy to maximize the drug efficacy and avoid the off-target effect. For instance, we discovered that the low antibody-binding affinity resulted in the formation of large clusters at the cell-cell interface, which could be important to control the downstream signaling pathways. We also tested different molecular architectures of the bispecific antibody and suggested the existence of an optimal length in regulating the T cell engagement. Overall, the current multiscale simulations serve as a proof-of-concept study to help in the future design of new biological therapeutics.
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Affiliation(s)
- Zhaoqian Su
- Data Science Institute, Vanderbilt University, Nashville, Tennessee
| | - Steven C Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York; Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, New York
| | - Yinghao Wu
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York.
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4
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Gall L, Duckworth C, Jardi F, Lammens L, Parker A, Bianco A, Kimko H, Pritchard DM, Pin C. Homeostasis, injury, and recovery dynamics at multiple scales in a self-organizing mouse intestinal crypt. eLife 2023; 12:e85478. [PMID: 38063302 PMCID: PMC10789491 DOI: 10.7554/elife.85478] [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: 12/09/2022] [Accepted: 12/07/2023] [Indexed: 01/16/2024] Open
Abstract
The maintenance of the functional integrity of the intestinal epithelium requires a tight coordination between cell production, migration, and shedding along the crypt-villus axis. Dysregulation of these processes may result in loss of the intestinal barrier and disease. With the aim of generating a more complete and integrated understanding of how the epithelium maintains homeostasis and recovers after injury, we have built a multi-scale agent-based model (ABM) of the mouse intestinal epithelium. We demonstrate that stable, self-organizing behaviour in the crypt emerges from the dynamic interaction of multiple signalling pathways, such as Wnt, Notch, BMP, ZNRF3/RNF43, and YAP-Hippo pathways, which regulate proliferation and differentiation, respond to environmental mechanical cues, form feedback mechanisms, and modulate the dynamics of the cell cycle protein network. The model recapitulates the crypt phenotype reported after persistent stem cell ablation and after the inhibition of the CDK1 cycle protein. Moreover, we simulated 5-fluorouracil (5-FU)-induced toxicity at multiple scales starting from DNA and RNA damage, which disrupts the cell cycle, cell signalling, proliferation, differentiation, and migration and leads to loss of barrier integrity. During recovery, our in silico crypt regenerates its structure in a self-organizing, dynamic fashion driven by dedifferentiation and enhanced by negative feedback loops. Thus, the model enables the simulation of xenobiotic-, in particular chemotherapy-, induced mechanisms of intestinal toxicity and epithelial recovery. Overall, we present a systems model able to simulate the disruption of molecular events and its impact across multiple levels of epithelial organization and demonstrate its application to epithelial research and drug development.
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Affiliation(s)
- Louis Gall
- Clinical Pharmacology and Quantitative Pharmacology, Clinical Pharmacology and Safety Sciences, R&D, AstraZenecaCambridgeUnited Kingdom
| | - Carrie Duckworth
- Institute of Systems, Molecular and Integrative Biology, University of LiverpoolLiverpoolUnited Kingdom
| | - Ferran Jardi
- Preclinical Sciences and Translational Safety, JanssenBeerseBelgium
| | - Lieve Lammens
- Preclinical Sciences and Translational Safety, JanssenBeerseBelgium
| | - Aimee Parker
- Gut Microbes and Health Programme, Quadram InstituteNorwichUnited Kingdom
| | - Ambra Bianco
- Clinical Pharmacology and Safety Sciences, AstraZenecaCambridgeUnited Kingdom
| | - Holly Kimko
- Clinical Pharmacology and Quantitative Pharmacology, Clinical Pharmacology and Safety Sciences, R&D, AstraZenecaCambridgeUnited Kingdom
| | - David Mark Pritchard
- Institute of Systems, Molecular and Integrative Biology, University of LiverpoolLiverpoolUnited Kingdom
| | - Carmen Pin
- Clinical Pharmacology and Quantitative Pharmacology, Clinical Pharmacology and Safety Sciences, R&D, AstraZenecaCambridgeUnited Kingdom
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5
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Germano DPJ, Zanca A, Johnston ST, Flegg JA, Osborne JM. Free and Interfacial Boundaries in Individual-Based Models of Multicellular Biological systems. Bull Math Biol 2023; 85:111. [PMID: 37805982 PMCID: PMC10560655 DOI: 10.1007/s11538-023-01214-8] [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: 06/05/2023] [Accepted: 09/11/2023] [Indexed: 10/10/2023]
Abstract
Coordination of cell behaviour is key to a myriad of biological processes including tissue morphogenesis, wound healing, and tumour growth. As such, individual-based computational models, which explicitly describe inter-cellular interactions, are commonly used to model collective cell dynamics. However, when using individual-based models, it is unclear how descriptions of cell boundaries affect overall population dynamics. In order to investigate this we define three cell boundary descriptions of varying complexities for each of three widely used off-lattice individual-based models: overlapping spheres, Voronoi tessellation, and vertex models. We apply our models to multiple biological scenarios to investigate how cell boundary description can influence tissue-scale behaviour. We find that the Voronoi tessellation model is most sensitive to changes in the cell boundary description with basic models being inappropriate in many cases. The timescale of tissue evolution when using an overlapping spheres model is coupled to the boundary description. The vertex model is demonstrated to be the most stable to changes in boundary description, though still exhibits timescale sensitivity. When using individual-based computational models one should carefully consider how cell boundaries are defined. To inform future work, we provide an exploration of common individual-based models and cell boundary descriptions in frequently studied biological scenarios and discuss their benefits and disadvantages.
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Affiliation(s)
- Domenic P. J. Germano
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010 Australia
| | - Adriana Zanca
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010 Australia
| | - Stuart T. Johnston
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010 Australia
| | - Jennifer A. Flegg
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010 Australia
| | - James M. Osborne
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010 Australia
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6
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Murali A, Sarkar RR. Mechano-immunology in microgravity. LIFE SCIENCES IN SPACE RESEARCH 2023; 37:50-64. [PMID: 37087179 DOI: 10.1016/j.lssr.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/16/2023] [Accepted: 03/05/2023] [Indexed: 05/03/2023]
Abstract
Life on Earth has evolved to thrive in the Earth's natural gravitational field; however, as space technology advances, we must revisit and investigate the effects of unnatural conditions on human health, such as gravitational change. Studies have shown that microgravity has a negative impact on various systemic parts of humans, with the effects being more severe in the human immune system. Increasing costs, limited experimental time, and sample handling issues hampered our understanding of this field. To address the existing knowledge gap and provide confidence in modelling the phenomena, in this review, we highlight experimental works in mechano-immunology under microgravity and different computational modelling approaches that can be used to address the existing problems.
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Affiliation(s)
- Anirudh Murali
- Chemical Engineering and Process Development, CSIR - National Chemical Laboratory, Pune, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ram Rup Sarkar
- Chemical Engineering and Process Development, CSIR - National Chemical Laboratory, Pune, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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7
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Muratore IB, Garnier S. Ontogeny of collective behaviour. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220065. [PMID: 36802780 PMCID: PMC9939274 DOI: 10.1098/rstb.2022.0065] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/21/2022] [Indexed: 02/21/2023] Open
Abstract
During their lifetime, superorganisms, like unitary organisms, undergo transformations that change the machinery of their collective behaviour. Here, we suggest that these transformations are largely understudied and propose that more systematic research into the ontogeny of collective behaviours is needed if we hope to better understand the link between proximate behavioural mechanisms and the development of collective adaptive functions. In particular, certain social insects engage in self-assemblage, forming dynamic and physically connected architectures with striking similarities to developing multicellular organisms, making them good model systems for ontogenetic studies of collective behaviour. However, exhaustive time series and three-dimensional data are required to thoroughly characterize the different life stages of the collective structures and the transitions between these stages. The well-established fields of embryology and developmental biology offer practical tools and theoretical frameworks that could speed up the acquisition of new knowledge about the formation, development, maturity and dissolution of social insect self-assemblages and, by extension, other superorganismal behaviours. We hope that this review will encourage an expansion of the ontogenetic perspective in the field of collective behaviour and, in particular, in self-assemblage research, which has far-reaching applications in robotics, computer science and regenerative medicine. This article is part of a discussion meeting issue 'Collective behaviour through time'.
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Affiliation(s)
| | - Simon Garnier
- Department of Biological Sciences, New Jersey Institute of Technology, Newark, NJ 07102, USA
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8
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Dawney NS, Cammarota C, Jia Q, Shipley A, Glichowski JA, Vasandani M, Finegan TM, Bergstralh DT. A novel tool for the unbiased characterization of epithelial monolayer development in culture. Mol Biol Cell 2023; 34:ar25. [PMID: 36696175 PMCID: PMC10092640 DOI: 10.1091/mbc.e22-04-0121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The function of an epithelial tissue is intertwined with its architecture. Epithelial tissues are often described as pseudo-two-dimensional, but this view may be partly attributed to experimental bias: many model epithelia, including cultured cell lines, are easiest to image from the "top-down." We measured the three-dimensional architecture of epithelial cells in culture and found that it varies dramatically across cultured regions, presenting a challenge for reproducibility and cross-study comparisons. We therefore developed a novel tool (Automated Layer Analysis, "ALAn") to characterize architecture in an unbiased manner. Using ALAn, we find that cultured epithelial cells can organize into four distinct architectures and that architecture correlates with cell density. Cells exhibit distinct biological properties in each architecture. Organization in the apical-basal axis is determined early in monolayer development by substrate availability, while disorganization in the apical-basal axis arises from an inability to form substrate connections. Our work highlights the need to carefully control for three-dimensional architecture when using cell culture as a model system for epithelial cell biology and introduces a novel tool, built on a set of rules that can be widely applied to epithelial cell culture.
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Affiliation(s)
- Nicole S Dawney
- Department of Biology, University of Rochester, Rochester, NY 14627
| | - Christian Cammarota
- Department of Physics & Astronomy, University of Rochester, Rochester, NY 14627
| | - Qingyuan Jia
- Department of Biology, University of Rochester, Rochester, NY 14627
| | - Alicia Shipley
- Department of Biology, University of Rochester, Rochester, NY 14627
| | - Joseph A Glichowski
- Department of Physics & Astronomy, University of Rochester, Rochester, NY 14627
| | | | - Tara M Finegan
- Department of Biology, University of Rochester, Rochester, NY 14627
| | - Dan T Bergstralh
- Department of Biology, University of Rochester, Rochester, NY 14627.,Department of Physics & Astronomy, University of Rochester, Rochester, NY 14627.,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14627
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9
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Hoehme S, Hammad S, Boettger J, Begher-Tibbe B, Bucur P, Vibert E, Gebhardt R, Hengstler JG, Drasdo D. Digital twin demonstrates significance of biomechanical growth control in liver regeneration after partial hepatectomy. iScience 2022; 26:105714. [PMID: 36691615 PMCID: PMC9860368 DOI: 10.1016/j.isci.2022.105714] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 06/23/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Partial liver removal is an important therapy option for liver cancer. In most patients within a few weeks, the liver is able to fully regenerate. In some patients, however, regeneration fails with often severe consequences. To better understand the control mechanisms of liver regeneration, experiments in mice were performed, guiding the creation of a spatiotemporal 3D model of the regenerating liver. The model represents cells and blood vessels within an entire liver lobe, a macroscopic liver subunit. The model could reproduce the experimental data only if a biomechanical growth control (BGC)-mechanism, inhibiting cell cycle entrance at high compression, was taken into account and predicted that BGC may act as a short-range growth inhibitor minimizing the number of proliferating neighbor cells of a proliferating cell, generating a checkerboard-like proliferation pattern. Model-predicted cell proliferation patterns in pigs and mice were found experimentally. The results underpin the importance of biomechanical aspects in liver growth control.
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Affiliation(s)
- Stefan Hoehme
- Interdisciplinary Centre for Bioinformatics (IZBI), University of Leipzig, Haertelstraße 16-18, 04107 Leipzig, Germany,Institute of Computer Science, University of Leipzig, Haertelstraße 16-18, 04107 Leipzig, Germany,Saxonian Incubator for Clinical Research (SIKT), Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany
| | - Seddik Hammad
- Section Molecular Hepatology, Department of Medicine II, Medical Faculty Mannheim, Heidelberg University, Germany,Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, 44139 Dortmund, Germany,Department of Forensic Medicine and Veterinary Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Jan Boettger
- Faculty of Medicine, Rudolf-Schoenheimer-Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
| | - Brigitte Begher-Tibbe
- Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, 44139 Dortmund, Germany
| | - Petru Bucur
- Unité INSERM 1193, Centre Hépato-Biliaire, Villejuif, France,Service de Chirurgie Digestive, CHU Trousseau, Tours, France
| | - Eric Vibert
- Unité INSERM 1193, Centre Hépato-Biliaire, Villejuif, France
| | - Rolf Gebhardt
- Faculty of Medicine, Rudolf-Schoenheimer-Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
| | - Jan G. Hengstler
- Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, 44139 Dortmund, Germany
| | - Dirk Drasdo
- Interdisciplinary Centre for Bioinformatics (IZBI), University of Leipzig, Haertelstraße 16-18, 04107 Leipzig, Germany,Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, 44139 Dortmund, Germany,Inria Paris & Sorbonne Université LJLL, 75012 Paris, France,Correspondence:
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10
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Malmi-Kakkada AN, Sinha S, Li X, Thirumalai D. Adhesion strength between cells regulate nonmonotonic growth by a biomechanical feedback mechanism. Biophys J 2022; 121:3719-3729. [PMID: 35505608 PMCID: PMC9617137 DOI: 10.1016/j.bpj.2022.04.032] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/22/2022] [Accepted: 04/26/2022] [Indexed: 11/24/2022] Open
Abstract
We determine how intercellular interactions and mechanical pressure experienced by single cells regulate cell proliferation using a minimal computational model for three-dimensional multicellular spheroid (MCS) growth. We discover that emergent spatial variations in the cell division rate, depending on the location of the cells either at the core or periphery within the MCS, is regulated by intercellular adhesion strength (fad). Varying fad results in nonmonotonic proliferation of cells in the MCS. A biomechanical feedback mechanism coupling the fad and microenvironment-dependent pressure fluctuations relative to a threshold value (pc) determines the onset of a dormant phase, and explains the nonmonotonic proliferation response. Increasing fad from low values enhances cell proliferation because pressure on individual cells is smaller compared with pc. However, at high fad, cells readily become dormant and cannot rearrange effectively in spacetime, leading to arrested cell proliferation. Utilizing our theoretical predictions, we explain experimental data on the impact of adhesion strength on cell proliferation and find good agreement. Our work, which shows that proliferation is regulated by pressure-adhesion feedback mechanism, may be a general feature of multicellular growth.
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Affiliation(s)
| | - Sumit Sinha
- Department of Physics, University of Texas at Austin, Austin, Texas
| | - Xin Li
- Department of Chemistry, University of Texas at Austin, Austin, Texas
| | - D Thirumalai
- Department of Chemistry, University of Texas at Austin, Austin, Texas.
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11
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Sinha S, Li X, Das R, Thirumalai D. Mechanical feedback controls the emergence of dynamical memory in growing tissue monolayers. J Chem Phys 2022; 156:245101. [DOI: 10.1063/5.0087815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The growth of a tissue, which depends on cell–cell interactions and biologically relevant processes such as cell division and apoptosis, is regulated by a mechanical feedback mechanism. We account for these effects in a minimal two-dimensional model in order to investigate the consequences of mechanical feedback, which is controlled by a critical pressure, p c. A cell can only grow and divide if its pressure, due to interaction with its neighbors, is less than p c. Because temperature is not a relevant variable, the cell dynamics is driven by self-generated active forces (SGAFs) that arise due to cell division. We show that even in the absence of intercellular interactions, cells undergo diffusive behavior. The SGAF-driven diffusion is indistinguishable from the well-known dynamics of a free Brownian particle at a fixed finite temperature. When intercellular interactions are taken into account, we find persistent temporal correlations in the force–force autocorrelation function (FAF) that extends over a timescale of several cell division times. The time-dependence of the FAF reveals memory effects, which increases as p c increases. The observed non-Markovian effects emerge due to the interplay of cell division and mechanical feedback and are inherently a non-equilibrium phenomenon.
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Affiliation(s)
- Sumit Sinha
- Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA
| | - Xin Li
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Rajsekhar Das
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - D. Thirumalai
- Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, USA
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12
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Camacho-Gómez D, García-Aznar JM, Gómez-Benito MJ. A 3D multi-agent-based model for lumen morphogenesis: the role of the biophysical properties of the extracellular matrix. ENGINEERING WITH COMPUTERS 2022; 38:4135-4149. [PMID: 36397878 PMCID: PMC9653332 DOI: 10.1007/s00366-022-01654-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/25/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED The correct function of many organs depends on proper lumen morphogenesis, which requires the orchestration of both biological and mechanical aspects. However, how these factors coordinate is not yet fully understood. Here, we focus on the development of a mechanistic model for computationally simulating lumen morphogenesis. In particular, we consider the hydrostatic pressure generated by the cells' fluid secretion as the driving force and the density of the extracellular matrix as regulators of the process. For this purpose, we develop a 3D agent-based-model for lumen morphogenesis that includes cells' fluid secretion and the density of the extracellular matrix. Moreover, this computer-based model considers the variation in the biological behavior of cells in response to the mechanical forces that they sense. Then, we study the formation of the lumen under different-mechanical scenarios and conclude that an increase in the matrix density reduces the lumen volume and hinders lumen morphogenesis. Finally, we show that the model successfully predicts normal lumen morphogenesis when the matrix density is physiological and aberrant multilumen formation when the matrix density is excessive. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00366-022-01654-1.
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Affiliation(s)
- Daniel Camacho-Gómez
- Department of Mechanical Engineering, Multiscale in Mechanical and Biological Engineering (M2BE), Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - José Manuel García-Aznar
- Department of Mechanical Engineering, Multiscale in Mechanical and Biological Engineering (M2BE), Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - María José Gómez-Benito
- Department of Mechanical Engineering, Multiscale in Mechanical and Biological Engineering (M2BE), Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
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13
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Hageb A, Thalheim T, Nattamai KJ, Möhrle B, Saçma M, Sakk V, Thielecke L, Cornils K, Grandy C, Port F, Gottschalk KE, Mallm JP, Glauche I, Galle J, Mulaw MA, Geiger H. Reduced adhesion of aged intestinal stem cells contributes to an accelerated clonal drift. Life Sci Alliance 2022; 5:5/8/e202201408. [PMID: 35487692 PMCID: PMC9057243 DOI: 10.26508/lsa.202201408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022] Open
Abstract
Analysis of clonal dynamics of intestinal stem cells supports an accelerated clonal drift upon aging, likely because of reduced adhesion of aged ISCs because of reduced canonical Wnt signaling. Upon aging, the function of the intestinal epithelium declines with a concomitant increase in aging-related diseases. ISCs play an important role in this process. It is known that ISC clonal dynamics follow a neutral drift model. However, it is not clear whether the drift model is still valid in aged ISCs. Tracking of clonal dynamics by clonal tracing revealed that aged crypts drift into monoclonality substantially faster than young ones. However, ISC tracing experiments, in vivo and ex vivo, implied a similar clonal expansion ability of both young and aged ISCs. Single-cell RNA sequencing for 1,920 high Lgr5 ISCs from young and aged mice revealed increased heterogeneity among subgroups of aged ISCs. Genes associated with cell adhesion were down-regulated in aged ISCs. ISCs of aged mice indeed show weaker adhesion to the matrix. Simulations applying a single cell–based model of the small intestinal crypt demonstrated an accelerated clonal drift at reduced adhesion strength, implying a central role for reduced adhesion for affecting clonal dynamics upon aging.
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Affiliation(s)
- Ali Hageb
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Torsten Thalheim
- Interdisciplinary Centre for Bioinformatics, University Leipzig, Leipzig, Germany
| | - Kalpana J Nattamai
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center (CCHMC), Cincinnati, OH, USA
| | - Bettina Möhrle
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Mehmet Saçma
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Vadim Sakk
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
| | - Lars Thielecke
- Institute for Medical Informatics and Biometry, Technische Universität Dresden, Dresden, Germany
| | - Kerstin Cornils
- Clinic of Pediatric Hematology and Oncology, Division of Pediatric Stem Cell Transplantation and Immunology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Research Institute Children's Cancer Center Hamburg, Hamburg, Germany
| | - Carolin Grandy
- Institute for Experimental Physics, Ulm University, Ulm, Germany
| | - Fabian Port
- Institute for Experimental Physics, Ulm University, Ulm, Germany
| | - Kay-E Gottschalk
- Institute for Experimental Physics, Ulm University, Ulm, Germany
| | - Jan-Philipp Mallm
- Division of Chromatin Networks, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ingmar Glauche
- Institute for Medical Informatics and Biometry, Technische Universität Dresden, Dresden, Germany
| | - Jörg Galle
- Interdisciplinary Centre for Bioinformatics, University Leipzig, Leipzig, Germany
| | - Medhanie A Mulaw
- Central Unit Single Cell Sequencing, Medical Faculty, Ulm University, Ulm, Germany
| | - Hartmut Geiger
- Institute of Molecular Medicine, Ulm University, Ulm, Germany
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14
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Van Liedekerke P, Gannoun L, Loriot A, Johann T, Lemaigre FP, Drasdo D. Quantitative modeling identifies critical cell mechanics driving bile duct lumen formation. PLoS Comput Biol 2022; 18:e1009653. [PMID: 35180209 PMCID: PMC8856558 DOI: 10.1371/journal.pcbi.1009653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 11/16/2021] [Indexed: 02/07/2023] Open
Abstract
Biliary ducts collect bile from liver lobules, the smallest functional and anatomical units of liver, and carry it to the gallbladder. Disruptions in this process caused by defective embryonic development, or through ductal reaction in liver disease have a major impact on life quality and survival of patients. A deep understanding of the processes underlying bile duct lumen formation is crucial to identify intervention points to avoid or treat the appearance of defective bile ducts. Several hypotheses have been proposed to characterize the biophysical mechanisms driving initial bile duct lumen formation during embryogenesis. Here, guided by the quantification of morphological features and expression of genes in bile ducts from embryonic mouse liver, we sharpened these hypotheses and collected data to develop a high resolution individual cell-based computational model that enables to test alternative hypotheses in silico. This model permits realistic simulations of tissue and cell mechanics at sub-cellular scale. Our simulations suggest that successful bile duct lumen formation requires a simultaneous contribution of directed cell division of cholangiocytes, local osmotic effects generated by salt excretion in the lumen, and temporally-controlled differentiation of hepatoblasts to cholangiocytes, with apical constriction of cholangiocytes only moderately affecting luminal size. The initial step in bile duct development is the formation of a biliary lumen, a process which involves several cellular mechanisms, such as cell division and polarization, and secretion of fluid. However, how these mechanisms are orchestrated in time and space is difficult to understand. Here, we built a computational model of biliary lumen formation which represents every cell and its function in detail. With the model we can simulate the effect of biophysical aspects that affect duct formation. We have tested the individual and combined effects of directed cell division, apical constriction, and osmotic effects on lumen expansion by varying the parameters that control their relative strength. Our simulations suggest that successful bile duct lumen formation requires the simultaneous contribution of directed cell division of cholangiocytes, local osmotic effects generated by salt excretion in the lumen, and temporally-controlled differentiation of hepatoblasts to cholangiocytes, with apical constriction of cholangiocytes only moderately affecting luminal size.
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Affiliation(s)
- Paul Van Liedekerke
- Inria Saclay Île-De-France, Palaiseau, France
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Inria de Paris & Sorbonne Université LJLL, Paris, France
- * E-mail: (PVL); (DD)
| | - Lila Gannoun
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Axelle Loriot
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Tim Johann
- Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, Dortmund, Germany
| | | | - Dirk Drasdo
- Inria Saclay Île-De-France, Palaiseau, France
- Leibniz Research Centre for Working Environment and Human Factors at the Technical University Dortmund, Dortmund, Germany
- Inria de Paris & Sorbonne Université LJLL, Paris, France
- * E-mail: (PVL); (DD)
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15
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Mathias S, Coulier A, Hellander A. CBMOS: a GPU-enabled Python framework for the numerical study of center-based models. BMC Bioinformatics 2022; 23:55. [PMID: 35100968 PMCID: PMC8805507 DOI: 10.1186/s12859-022-04575-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 01/11/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Cell-based models are becoming increasingly popular for applications in developmental biology. However, the impact of numerical choices on the accuracy and efficiency of the simulation of these models is rarely meticulously tested. Without concrete studies to differentiate between solid model conclusions and numerical artifacts, modelers are at risk of being misled by their experiments' results. Most cell-based modeling frameworks offer a feature-rich environment, providing a wide range of biological components, but are less suitable for numerical studies. There is thus a need for software specifically targeted at this use case. RESULTS We present CBMOS, a Python framework for the simulation of the center-based or cell-centered model. Contrary to other implementations, CBMOS' focus is on facilitating numerical study of center-based models by providing access to multiple ordinary differential equation solvers and force functions through a flexible, user-friendly interface and by enabling rapid testing through graphics processing unit (GPU) acceleration. We show-case its potential by illustrating two common workflows: (1) comparison of the numerical properties of two solvers within a Jupyter notebook and (2) measuring average wall times of both solvers on a high performance computing cluster. More specifically, we confirm that although for moderate accuracy levels the backward Euler method allows for larger time step sizes than the commonly used forward Euler method, its additional computational cost due to being an implicit method prohibits its use for practical test cases. CONCLUSIONS CBMOS is a flexible, easy-to-use Python implementation of the center-based model, exposing both basic model assumptions and numerical components to the user. It is available on GitHub and PyPI under an MIT license. CBMOS allows for fast prototyping on a central processing unit for small systems through the use of NumPy. Using CuPy on a GPU, cell populations of up to 10,000 cells can be simulated within a few seconds. As such, it will substantially lower the time investment for any modeler to check the crucial assumption that model conclusions are independent of numerical issues.
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Affiliation(s)
- Sonja Mathias
- Department of Information Technology, Uppsala University, Uppsala, Sweden
| | - Adrien Coulier
- Department of Information Technology, Uppsala University, Uppsala, Sweden
| | - Andreas Hellander
- Department of Information Technology, Uppsala University, Uppsala, Sweden
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16
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Rozman J, Krajnc M, Ziherl P. Morphologies of compressed active epithelial monolayers. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:99. [PMID: 34287727 DOI: 10.1140/epje/s10189-021-00094-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Using a three-dimensional active vertex model, we numerically study the shapes of strained unsupported epithelial monolayers subject to active junctional noise due to stochastic binding and unbinding of myosin. We find that while uniaxial, biaxial, and isotropic in-plane compressive strains do lead to the formation of longitudinal, herringbone pattern, and labyrinthine folds, respectively, the villus morphology characteristic of, e.g., the small intestine appears only if junctional tension fluctuations are strong enough to fluidize the tissue. Moreover, the fluidized epithelium features villi even in the absence of compressive strain provided that the apico-basal differential surface tension is large enough. We analyze several details of the different epithelial forms including the role of strain rate and the modulation of tissue thickness across folds. Our results show that even unsupported, non-patterned epithelia can form nontrivial morphologies.
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Affiliation(s)
- Jan Rozman
- Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia.
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia.
| | - Matej Krajnc
- Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
| | - Primož Ziherl
- Jožef Stefan Institute, Jamova 39, 1000, Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000, Ljubljana, Slovenia
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17
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Hofmann F, Thalheim T, Rother K, Quaas M, Kerner C, Przybilla J, Aust G, Galle J. How to Obtain a Mega-Intestine with Normal Morphology: In Silico Modelling of Postnatal Intestinal Growth in a Cd97-Transgenic Mouse. Int J Mol Sci 2021; 22:ijms22147345. [PMID: 34298973 PMCID: PMC8305140 DOI: 10.3390/ijms22147345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/29/2021] [Accepted: 07/02/2021] [Indexed: 11/19/2022] Open
Abstract
Intestinal cylindrical growth peaks in mice a few weeks after birth, simultaneously with crypt fission activity. It nearly stops after weaning and cannot be reactivated later. Transgenic mice expressing Cd97/Adgre5 in the intestinal epithelium develop a mega-intestine with normal microscopic morphology in adult mice. Here, we demonstrate premature intestinal differentiation in Cd97/Adgre5 transgenic mice at both the cellular and molecular levels until postnatal day 14. Subsequently, the growth of the intestinal epithelium becomes activated and its maturation suppressed. These changes are paralleled by postnatal regulation of growth factors and by an increased expression of secretory cell markers, suggesting growth activation of non-epithelial tissue layers as the origin of enforced tissue growth. To understand postnatal intestinal growth mechanistically, we study epithelial fate decisions during this period with the use of a 3D individual cell-based computer model. In the model, the expansion of the intestinal stem cell (SC) population, a prerequisite for crypt fission, is largely independent of the tissue growth rate and is therefore not spontaneously adaptive. Accordingly, the model suggests that, besides the growth activation of non-epithelial tissue layers, the formation of a mega-intestine requires a released growth control in the epithelium, enabling accelerated SC expansion. The similar intestinal morphology in Cd97/Adgre5 transgenic and wild type mice indicates a synchronization of tissue growth and SC expansion, likely by a crypt density-controlled contact inhibition of growth of intestinal SC proliferation. The formation of a mega-intestine with normal microscopic morphology turns out to originate in changes of autonomous and conditional specification of the intestinal cell fate induced by the activation of Cd97/Adgre5.
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Affiliation(s)
- Felix Hofmann
- Research Laboratories, Department of Surgery, Leipzig University, 04107 Leipzig, Germany; (K.R.); (M.Q.); (C.K.); (G.A.)
- Correspondence: (F.H.); (T.T.)
| | - Torsten Thalheim
- Interdisciplinary Institute for Bioinformatics (IZBI), Leipzig University, 04107 Leipzig, Germany;
- Correspondence: (F.H.); (T.T.)
| | - Karen Rother
- Research Laboratories, Department of Surgery, Leipzig University, 04107 Leipzig, Germany; (K.R.); (M.Q.); (C.K.); (G.A.)
- Interdisciplinary Institute for Bioinformatics (IZBI), Leipzig University, 04107 Leipzig, Germany;
| | - Marianne Quaas
- Research Laboratories, Department of Surgery, Leipzig University, 04107 Leipzig, Germany; (K.R.); (M.Q.); (C.K.); (G.A.)
| | - Christiane Kerner
- Research Laboratories, Department of Surgery, Leipzig University, 04107 Leipzig, Germany; (K.R.); (M.Q.); (C.K.); (G.A.)
| | - Jens Przybilla
- Institute for Medical Informatics, Statistics and Epidemiology (IMISE), Leipzig University, 04107 Leipzig, Germany;
| | - Gabriela Aust
- Research Laboratories, Department of Surgery, Leipzig University, 04107 Leipzig, Germany; (K.R.); (M.Q.); (C.K.); (G.A.)
| | - Joerg Galle
- Interdisciplinary Institute for Bioinformatics (IZBI), Leipzig University, 04107 Leipzig, Germany;
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18
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Aghaallaei N, Dick AM, Tsingos E, Inoue D, Hasel E, Thumberger T, Toyoda A, Leptin M, Wittbrodt J, Bajoghli B. αβ/γδ T cell lineage outcome is regulated by intrathymic cell localization and environmental signals. SCIENCE ADVANCES 2021; 7:7/29/eabg3613. [PMID: 34261656 PMCID: PMC8279519 DOI: 10.1126/sciadv.abg3613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/28/2021] [Indexed: 05/07/2023]
Abstract
αβ and γδ T cells are two distinct sublineages that develop in the vertebrate thymus. Thus far, their differentiation from a common progenitor is mostly understood to be regulated by intrinsic mechanisms. However, the proportion of αβ/γδ T cells varies in different vertebrate taxa. How this process is regulated in species that tend to produce a high frequency of γδ T cells is unstudied. Using an in vivo teleost model, the medaka, we report that progenitors first enter a thymic niche where their development into γδ T cells is favored. Translocation from this niche, mediated by chemokine receptor Ccr9b, is a prerequisite for their differentiation into αβ T cells. On the other hand, the thymic niche also generates opposing gradients of the cytokine interleukin-7 and chemokine Ccl25a, and, together, they influence the lineage outcome. We propose a previously unknown mechanism that determines the proportion of αβ/γδ lineages within species.
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Affiliation(s)
- Narges Aghaallaei
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Advaita M Dick
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany
| | - Erika Tsingos
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Daigo Inoue
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Eva Hasel
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Thomas Thumberger
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Atsushi Toyoda
- Comparative Genomics Laboratory, Department of Genomics and Evolutionary Biology, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Maria Leptin
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
- EMBO, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| | - Joachim Wittbrodt
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Baubak Bajoghli
- Department of Hematology, Oncology, Immunology, and Rheumatology, University Hospital of Tübingen, Otfried-Müller-Strasse 10, 72076 Tübingen, Germany.
- European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg, Germany
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19
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Miller C, Crampin E, Osborne JM. Maintaining the proliferative cell niche in multicellular models of epithelia. J Theor Biol 2021; 527:110807. [PMID: 34119497 DOI: 10.1016/j.jtbi.2021.110807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 03/23/2021] [Accepted: 06/04/2021] [Indexed: 11/29/2022]
Abstract
The maintenance of the proliferative cell niche is critical to epithelial tissue morphology and function. In this paper we investigate how current modelling methods can result in the erroneous loss of proliferative cells from the proliferative cell niche. Using an established model of the inter-follicular epidermis we find there is a limit to the proliferative cell densities that can be maintained in the basal layer (the niche) if we do not include additional mechanisms to stop the loss of proliferative cells from the niche. We suggest a new methodology that enables maintenance of a desired homeostatic population of proliferative cells in the niche: a rotational force is applied to the two daughter cells during the mitotic phase of division to enforce a particular division direction. We demonstrate that this new methodology achieves this goal. This methodology reflects the regulation of the orientation of cell division.
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Affiliation(s)
- Claire Miller
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010, Australia; Systems Biology Laboratory, School of Mathematics and Statistics and Department of Biomedical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Edmund Crampin
- Systems Biology Laboratory, School of Mathematics and Statistics and Department of Biomedical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia; School of Medicine, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Melbourne School of Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - James M Osborne
- School of Mathematics and Statistics, The University of Melbourne, Parkville, Victoria 3010, Australia.
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20
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Macnamara CK. Biomechanical modelling of cancer: Agent‐based force‐based models of solid tumours within the context of the tumour microenvironment. COMPUTATIONAL AND SYSTEMS ONCOLOGY 2021. [DOI: 10.1002/cso2.1018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Cicely K. Macnamara
- School of Mathematics and Statistics Mathematical Institute University of St Andrews St Andrews Fife UK
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21
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Guerra A, Belinha J, Natal Jorge R. A preliminary study of endothelial cell migration during angiogenesis using a meshless method approach. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2020; 36:e3393. [PMID: 32783379 DOI: 10.1002/cnm.3393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 08/03/2020] [Accepted: 08/07/2020] [Indexed: 06/11/2023]
Abstract
Angiogenesis, the development of new blood capillaries, is crucial for the wound healing process. This biological process allows the proper blood supply to the tissue, essential for cell proliferation and viability. Several biological factors modulate angiogenesis, however the vascular endothelial growth factor (VEGF) is the main one. Given the complexity of angiogenesis, in the last years, computational modelling aroused the interest of scientists since it allows to model this process with different, more economic and faster methodologies, comparatively to experimental approaches. In this work, a mathematical model motivated by the analysis of the effect of VEGF diffusion gradient in endothelial cell migration is presented. This is the process that allows capillary formation and it is essential for angiogenesis. The proposed mathematical model is combined with the Radial Point Interpolation Method, being the area discretized considering an unorganized nodal cloud and a background mesh of integration points, without predefined relations. The nodal connectivity was achieved using the "influence-domain" approach. The interpolation functions were constructed using the Radial Point Interpolators techniques. This method combines a radial basis functions with a polynomial functions to obtain the approximation. This preliminary work does not account for the whole complexity of cell and tissue biology, and numerical results are presented for an idealised two-dimensional setting. Nevertheless, the developed RPIM software is a valid numerical tool that can be adjusted to biological problems and may also be able to complement the biological and medical subjects.
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Affiliation(s)
- Ana Guerra
- Institute of Science and Innovation in Mechanical and Industrial Engineering (INEGI), Porto, Portugal
| | - Jorge Belinha
- School of Engineering, Polytechnic of Porto (ISEP), Mechanical Engineering Department, Porto, Portugal
| | - Renato Natal Jorge
- LAETA, INEGI, Porto, Portugal
- Mechanical Engineering Department, University of Porto (FEUP), Porto, Portugal
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22
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Mathias S, Coulier A, Bouchnita A, Hellander A. Impact of Force Function Formulations on the Numerical Simulation of Centre-Based Models. Bull Math Biol 2020; 82:132. [PMID: 33025278 PMCID: PMC7538447 DOI: 10.1007/s11538-020-00810-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 09/21/2020] [Indexed: 12/17/2022]
Abstract
Centre-based or cell-centre models are a framework for the computational study of multicellular systems with widespread use in cancer modelling and computational developmental biology. At the core of these models are the numerical method used to update cell positions and the force functions that encode the pairwise mechanical interactions of cells. For the latter, there are multiple choices that could potentially affect both the biological behaviour captured, and the robustness and efficiency of simulation. For example, available open-source software implementations of centre-based models rely on different force functions for their default behaviour and it is not straightforward for a modeller to know if these are interchangeable. Our study addresses this problem and contributes to the understanding of the potential and limitations of three popular force functions from a numerical perspective. We show empirically that choosing the force parameters such that the relaxation time for two cells after cell division is consistent between different force functions results in good agreement of the population radius of a two-dimensional monolayer relaxing mechanically after intense cell proliferation. Furthermore, we report that numerical stability is not sufficient to prevent unphysical cell trajectories following cell division, and consequently, that too large time steps can cause geometrical differences at the population level.
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Affiliation(s)
- Sonja Mathias
- Department of Information Technology, Uppsala University, Uppsala, Sweden.
| | - Adrien Coulier
- Department of Information Technology, Uppsala University, Uppsala, Sweden
| | - Anass Bouchnita
- Department of Information Technology, Uppsala University, Uppsala, Sweden
- Ecole Centrale Casablanca, Bouskoura, Morocco
| | - Andreas Hellander
- Department of Information Technology, Uppsala University, Uppsala, Sweden
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23
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Murphy RJ, Buenzli PR, Baker RE, Simpson MJ. Mechanical Cell Competition in Heterogeneous Epithelial Tissues. Bull Math Biol 2020; 82:130. [PMID: 32979100 DOI: 10.1007/s11538-020-00807-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/09/2020] [Indexed: 12/11/2022]
Abstract
Mechanical cell competition is important during tissue development, cancer invasion, and tissue ageing. Heterogeneity plays a key role in practical applications since cancer cells can have different cell stiffness and different proliferation rates than normal cells. To study this phenomenon, we propose a one-dimensional mechanical model of heterogeneous epithelial tissue dynamics that includes cell-length-dependent proliferation and death mechanisms. Proliferation and death are incorporated into the discrete model stochastically and arise as source/sink terms in the corresponding continuum model that we derive. Using the new discrete model and continuum description, we explore several applications including the evolution of homogeneous tissues experiencing proliferation and death, and competition in a heterogeneous setting with a cancerous tissue competing for space with an adjacent normal tissue. This framework allows us to postulate new mechanisms that explain the ability of cancer cells to outcompete healthy cells through mechanical differences rather than an intrinsic proliferative advantage. We advise when the continuum model is beneficial and demonstrate why naively adding source/sink terms to a continuum model without considering the underlying discrete model may lead to incorrect results.
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Affiliation(s)
- Ryan J Murphy
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia.
| | - Pascal R Buenzli
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Ruth E Baker
- Mathematical Institute, University of Oxford, Oxford, UK
| | - Matthew J Simpson
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
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24
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Giniūnaitė R, Baker RE, Kulesa PM, Maini PK. Modelling collective cell migration: neural crest as a model paradigm. J Math Biol 2020; 80:481-504. [PMID: 31587096 PMCID: PMC7012984 DOI: 10.1007/s00285-019-01436-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 09/09/2019] [Indexed: 12/01/2022]
Abstract
A huge variety of mathematical models have been used to investigate collective cell migration. The aim of this brief review is twofold: to present a number of modelling approaches that incorporate the key factors affecting cell migration, including cell-cell and cell-tissue interactions, as well as domain growth, and to showcase their application to model the migration of neural crest cells. We discuss the complementary strengths of microscale and macroscale models, and identify why it can be important to understand how these modelling approaches are related. We consider neural crest cell migration as a model paradigm to illustrate how the application of different mathematical modelling techniques, combined with experimental results, can provide new biological insights. We conclude by highlighting a number of future challenges for the mathematical modelling of neural crest cell migration.
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Affiliation(s)
- Rasa Giniūnaitė
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK.
| | - Ruth E Baker
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
| | - Paul M Kulesa
- Stowers Institute for Medical Research, 1000 E 50th Street, Kansas City, MO, 64110, USA
| | - Philip K Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Road, Oxford, OX2 6GG, UK
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25
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Van Liedekerke P, Neitsch J, Johann T, Warmt E, Gonzàlez-Valverde I, Hoehme S, Grosser S, Kaes J, Drasdo D. A quantitative high-resolution computational mechanics cell model for growing and regenerating tissues. Biomech Model Mechanobiol 2019; 19:189-220. [PMID: 31749071 PMCID: PMC7005086 DOI: 10.1007/s10237-019-01204-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 07/16/2019] [Indexed: 12/19/2022]
Abstract
Mathematical models are increasingly designed to guide experiments in biology, biotechnology, as well as to assist in medical decision making. They are in particular important to understand emergent collective cell behavior. For this purpose, the models, despite still abstractions of reality, need to be quantitative in all aspects relevant for the question of interest. This paper considers as showcase example the regeneration of liver after drug-induced depletion of hepatocytes, in which the surviving and dividing hepatocytes must squeeze in between the blood vessels of a network to refill the emerged lesions. Here, the cells' response to mechanical stress might significantly impact the regeneration process. We present a 3D high-resolution cell-based model integrating information from measurements in order to obtain a refined and quantitative understanding of the impact of cell-biomechanical effects on the closure of drug-induced lesions in liver. Our model represents each cell individually and is constructed by a discrete, physically scalable network of viscoelastic elements, capable of mimicking realistic cell deformation and supplying information at subcellular scales. The cells have the capability to migrate, grow, and divide, and the nature and parameters of their mechanical elements can be inferred from comparisons with optical stretcher experiments. Due to triangulation of the cell surface, interactions of cells with arbitrarily shaped (triangulated) structures such as blood vessels can be captured naturally. Comparing our simulations with those of so-called center-based models, in which cells have a largely rigid shape and forces are exerted between cell centers, we find that the migration forces a cell needs to exert on its environment to close a tissue lesion, is much smaller than predicted by center-based models. To stress generality of the approach, the liver simulations were complemented by monolayer and multicellular spheroid growth simulations. In summary, our model can give quantitative insight in many tissue organization processes, permits hypothesis testing in silico, and guide experiments in situations in which cell mechanics is considered important.
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Affiliation(s)
- Paul Van Liedekerke
- Inria Paris & Sorbonne Université LJLL, 2 Rue Simone IFF, 75012, Paris, France. .,IfADo - Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund, Germany.
| | - Johannes Neitsch
- Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstr. 16-18, 04107, Leipzig, Germany
| | - Tim Johann
- IfADo - Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund, Germany
| | - Enrico Warmt
- Faculty of Physics and Earth Science, Peter Debye Institute for Soft Matter Physics, Leipzig University, Linnéstraße 5, 04103, Leipzig, Germany
| | | | - Stefan Hoehme
- Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstr. 16-18, 04107, Leipzig, Germany.,Institute for Computer Science, Leipzig University, Härtelstr. 16-18, 04107, Leipzig, Germany
| | - Steffen Grosser
- Faculty of Physics and Earth Science, Peter Debye Institute for Soft Matter Physics, Leipzig University, Linnéstraße 5, 04103, Leipzig, Germany
| | - Josef Kaes
- Faculty of Physics and Earth Science, Peter Debye Institute for Soft Matter Physics, Leipzig University, Linnéstraße 5, 04103, Leipzig, Germany
| | - Dirk Drasdo
- Inria Paris & Sorbonne Université LJLL, 2 Rue Simone IFF, 75012, Paris, France. .,IfADo - Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund, Germany. .,Interdisciplinary Centre for Bioinformatics, Leipzig University, Härtelstr. 16-18, 04107, Leipzig, Germany.
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26
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Matsiaka OM, Baker RE, Simpson MJ. Continuum descriptions of spatial spreading for heterogeneous cell populations: Theory and experiment. J Theor Biol 2019; 482:109997. [PMID: 31491498 DOI: 10.1016/j.jtbi.2019.109997] [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: 05/28/2019] [Revised: 08/16/2019] [Accepted: 09/03/2019] [Indexed: 11/19/2022]
Abstract
Variability in cell populations is frequently observed in both in vitro and in vivo settings. Intrinsic differences within populations of cells, such as differences in cell sizes or differences in rates of cell motility, can be present even within a population of cells from the same cell line. We refer to this variability as cell heterogeneity. Mathematical models of cell migration, for example, in the context of tumour growth and metastatic invasion, often account for both undirected (random) migration and directed migration that is mediated by cell-to-cell contacts and cell-to-cell adhesion. A key feature of standard models is that they often assume that the population is composed of identical cells with constant properties. This leads to relatively simple single-species homogeneous models that neglect the role of heterogeneity. In this work, we use a continuum modelling approach to explore the role of heterogeneity in spatial spreading of cell populations. We employ a three-species heterogeneous model of cell motility that explicitly incorporates different types of experimentally-motivated heterogeneity in cell sizes: (i) monotonically decreasing; (ii) uniform; (iii) non-monotonic; and (iv) monotonically increasing distributions of cell size. Comparing the density profiles generated by the three-species heterogeneous model with density profiles predicted by a more standard single-species homogeneous model reveals that when we are dealing with monotonically decreasing and uniform distributions a simple and computationally efficient single-species homogeneous model can be remarkably accurate in describing the evolution of a heterogeneous cell population. In contrast, we find that the simpler single-species homogeneous model performs relatively poorly when applied to non-monotonic and monotonically increasing distributions of cell sizes. Additional results for heterogeneity in parameters describing both undirected and directed cell migration are also considered, and we find that similar results apply.
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Affiliation(s)
- Oleksii M Matsiaka
- School of Mathematical Sciences, Queensland University of Technology (QUT) Brisbane, Queensland, Australia
| | - Ruth E Baker
- Mathematical Institute, University of Oxford, Radcliffe Observatory Quarter, Woodstock Road, Oxford, United Kingdom
| | - Matthew J Simpson
- School of Mathematical Sciences, Queensland University of Technology (QUT) Brisbane, Queensland, Australia.
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27
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Escribano J, Chen MB, Moeendarbary E, Cao X, Shenoy V, Garcia-Aznar JM, Kamm RD, Spill F. Balance of mechanical forces drives endothelial gap formation and may facilitate cancer and immune-cell extravasation. PLoS Comput Biol 2019; 15:e1006395. [PMID: 31048903 PMCID: PMC6497229 DOI: 10.1371/journal.pcbi.1006395] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/10/2018] [Indexed: 11/29/2022] Open
Abstract
The formation of gaps in the endothelium is a crucial process underlying both cancer and immune cell extravasation, contributing to the functioning of the immune system during infection, the unfavorable development of chronic inflammation and tumor metastasis. Here, we present a stochastic-mechanical multiscale model of an endothelial cell monolayer and show that the dynamic nature of the endothelium leads to spontaneous gap formation, even without intervention from the transmigrating cells. These gaps preferentially appear at the vertices between three endothelial cells, as opposed to the border between two cells. We quantify the frequency and lifetime of these gaps, and validate our predictions experimentally. Interestingly, we find experimentally that cancer cells also preferentially extravasate at vertices, even when they first arrest on borders. This suggests that extravasating cells, rather than initially signaling to the endothelium, might exploit the autonomously forming gaps in the endothelium to initiate transmigration.
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Affiliation(s)
- Jorge Escribano
- Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Michelle B. Chen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Emad Moeendarbary
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Xuan Cao
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Vivek Shenoy
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - Roger D. Kamm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- BioSystems and Micromechanics (BioSyM), Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
| | - Fabian Spill
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- School of Mathematics, University of Birmingham, Birmingham, United Kingdom
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28
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Bouchnita A, Hellander S, Hellander A. A 3D Multiscale Model to Explore the Role of EGFR Overexpression in Tumourigenesis. Bull Math Biol 2019; 81:2323-2344. [PMID: 31016574 PMCID: PMC6612322 DOI: 10.1007/s11538-019-00607-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/15/2019] [Indexed: 11/30/2022]
Abstract
The epidermal growth factor receptor (EGFR) signalling cascade is one of the main pathways that regulate the survival and division of mammalian cells. It is also one of the most altered transduction pathways in cancer. Acquired mutations in the EGFR/ERK pathway can cause the overexpression of EGFR on the surface of the cell, while others downregulate the inactivation of switched on intracellular proteins such as Ras and Raf. This upregulates the activity of ERK and promotes cell division. We develop a 3D multiscale model to explore the role of EGFR overexpression on tumour initiation. In this model, cells are described as individual objects that move, interact, divide, proliferate, and die by apoptosis. We use Brownian Dynamics to describe the extracellular and intracellular regulations of cells as well as the spatial and stochastic effects influencing them. The fate of each cell depends on the number of active transcription factors in the nucleus. We use numerical simulations to investigate the individual and combined effects of mutations on the intracellular regulation of individual cells. Next, we show that the distance between active receptors increase the level of EGFR/ERK signalling. We demonstrate the usefulness of the model by quantifying the impact of mutational alterations in the EGFR/ERK pathway on the growth rate of in silico tumours.
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Affiliation(s)
- Anass Bouchnita
- Division of Scientific Computing, Department of Information Technology, Uppsala University, 75105, Uppsala, Sweden.
| | - Stefan Hellander
- Division of Scientific Computing, Department of Information Technology, Uppsala University, 75105, Uppsala, Sweden
| | - Andreas Hellander
- Division of Scientific Computing, Department of Information Technology, Uppsala University, 75105, Uppsala, Sweden
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29
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Quantitative cell-based model predicts mechanical stress response of growing tumor spheroids over various growth conditions and cell lines. PLoS Comput Biol 2019; 15:e1006273. [PMID: 30849070 PMCID: PMC6538187 DOI: 10.1371/journal.pcbi.1006273] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 05/28/2019] [Accepted: 10/31/2018] [Indexed: 11/19/2022] Open
Abstract
Model simulations indicate that the response of growing cell populations on mechanical stress follows the same functional relationship and is predictable over different cell lines and growth conditions despite experimental response curves look largely different. We develop a hybrid model strategy in which cells are represented by coarse-grained individual units calibrated with a high resolution cell model and parameterized by measurable biophysical and cell-biological parameters. Cell cycle progression in our model is controlled by volumetric strain, the latter being derived from a bio-mechanical relation between applied pressure and cell compressibility. After parameter calibration from experiments with mouse colon carcinoma cells growing against the resistance of an elastic alginate capsule, the model adequately predicts the growth curve in i) soft and rigid capsules, ii) in different experimental conditions where the mechanical stress is generated by osmosis via a high molecular weight dextran solution, and iii) for other cell types with different growth kinetics from the growth kinetics in absence of external stress. Our model simulation results suggest a generic, even quantitatively same, growth response of cell populations upon externally applied mechanical stress, as it can be quantitatively predicted using the same growth progression function.
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30
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Guerra A, Belinha J, Jorge RN. Modelling skin wound healing angiogenesis: A review. J Theor Biol 2018; 459:1-17. [PMID: 30240579 DOI: 10.1016/j.jtbi.2018.09.020] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 12/22/2022]
Abstract
The occurrence of wounds is a main health concern in Western society due to their high frequency and treatment cost. During wound healing, the formation of a functional blood vessel network through angiogenesis is an essential process. Angiogenesis allows the reestablishment of the normal blood flow, the sufficient exchange of oxygen and nutrients and the removal of metabolic waste, necessary for cell proliferation and viability. Mathematical and computational models provide new tools to improve the healing process. In fact, over the last thirty years, in silico models have been continuously formulated to describe the effect of several biological and mechanical factors in angiogenesis during wound healing. Additionally, with different levels of complexity, these models allow coupling the human skin structure, to distinct cell types and growth factors, to study extracellular matrix composition and to understand its deformation. This paper discusses how in silico models, which are more economical and less time-consuming comparatively to laboratory methodologies, can help test new strategies to promote/optimize angiogenesis. The continuum, cell-based and hybrid mathematical models of wound healing angiogenesis are reviewed in the present paper, in order to identify possible improvements. Accordingly, the development of higher dimension models incorporating multiscale analysis at molecular, cellular and tissue level remains a challenge that future models should consider.
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Affiliation(s)
- Ana Guerra
- INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto 4200-465, Portugal.
| | - Jorge Belinha
- ISEP, School of Engineering, Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, Porto 4200-072, Portugal.
| | - Renato Natal Jorge
- INEGI, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, Porto 4200-465, Portugal.
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31
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Christensen A, West AKV, Wullkopf L, Terra Erler J, Oddershede LB, Mathiesen J. Friction-limited cell motility in confluent monolayer tissue. Phys Biol 2018; 15:066004. [DOI: 10.1088/1478-3975/aacedc] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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32
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Chen J, Weihs D, Van Dijk M, Vermolen FJ. A phenomenological model for cell and nucleus deformation during cancer metastasis. Biomech Model Mechanobiol 2018; 17:1429-1450. [PMID: 29845458 PMCID: PMC6154301 DOI: 10.1007/s10237-018-1036-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/21/2018] [Indexed: 12/21/2022]
Abstract
Cell migration plays an essential role in cancer metastasis. In cancer invasion through confined spaces, cells must undergo extensive deformation, which is a capability related to their metastatic potentials. Here, we simulate the deformation of the cell and nucleus during invasion through a dense, physiological microenvironment by developing a phenomenological computational model. In our work, cells are attracted by a generic emitting source (e.g., a chemokine or stiffness signal), which is treated by using Green’s Fundamental solutions. We use an IMEX integration method where the linear parts and the nonlinear parts are treated by using an Euler backward scheme and an Euler forward method, respectively. We develop the numerical model for an obstacle-induced deformation in 2D or/and 3D. Considering the uncertainty in cell mobility, stochastic processes are incorporated and uncertainties in the input variables are evaluated using Monte Carlo simulations. This quantitative study aims at estimating the likelihood for invasion and the length of the time interval in which the cell invades the tissue through an obstacle. Subsequently, the two-dimensional cell deformation model is applied to simplified cancer metastasis processes to serve as a model for in vivo or in vitro biomedical experiments.
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Affiliation(s)
- Jiao Chen
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands.
| | - Daphne Weihs
- Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Marcel Van Dijk
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands
| | - Fred J Vermolen
- Delft Institute of Applied Mathematics, Delft University of Technology, Delft, The Netherlands
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33
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Omidvar R, Tafazzoli-Shadpour M, Mahmoodi-Nobar F, Azadi S, Khani MM. Quantifying effects of cyclic stretch on cell-collagen substrate adhesiveness of vascular endothelial cells. Proc Inst Mech Eng H 2018; 232:531-541. [PMID: 29609522 DOI: 10.1177/0954411918767477] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vascular endothelium is continuously subjected to mechanical stimulation in the form of shear forces due to blood flow as well as tensile forces as a consequence of blood pressure. Such stimuli influence endothelial behavior and regulate cell-tissue interaction for an optimized functionality. This study aimed to quantify influence of cyclic stretch on the adhesive property and stiffness of endothelial cells. The 10% cyclic stretch with frequency of 1 Hz was applied to a layer of endothelial cells cultured on a polydimethylsiloxane substrate. Cell-substrate adhesion of endothelial cells was examined by the novel approach of atomic force microscope-based single-cell force spectroscopy and cell stiffness was measured by atomic force microscopy. Furthermore, the adhesive molecular bonds were evaluated using modified Hertz contact theory. Our results show that overall adhesion of endothelial cells with substrate decreased after cyclic stretch while they became stiffer. Based on the experimental results and theoretical modeling, the decrease in the number of molecular bonds after cyclic stretch was quantified. In conclusion, in vitro cyclic stretch caused alterations in both adhesive capacity and elastic modulus of endothelial cells through mechanotransductive pathways as two major determinants of the function of these cells within the cardiovascular system.
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Affiliation(s)
- Ramin Omidvar
- 1 Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran.,2 Centre for Biological Signalling Studies (BIOSS), Albert-Ludwig-University Freiburg, Schötzerstraße 18, 79104 Freibug, Germany
| | - Mohammad Tafazzoli-Shadpour
- 1 Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran
| | - Farbod Mahmoodi-Nobar
- 1 Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran
| | - Shohreh Azadi
- 1 Cardiovascular Engineering Lab, Faculty of Biomedical Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran
| | - Mohammad-Mehdi Khani
- 3 Medical Nanotechnology and Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,4 Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Erabi St, Yaman St, Tehran, Iran
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34
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Model Prediction and Validation of an Order Mechanism Controlling the Spatiotemporal Phenotype of Early Hepatocellular Carcinoma. Bull Math Biol 2018; 80:1134-1171. [PMID: 29568983 DOI: 10.1007/s11538-017-0375-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 11/27/2017] [Indexed: 12/11/2022]
Abstract
Recently, hepatocyte-sinusoid alignment (HSA) has been identified as a mechanism that supports the coordination of hepatocytes during liver regeneration to reestablish a functional micro-architecture (Hoehme et al. in Proc Natl Acad Sci 107(23):10371-10376, 2010). HSA means that hepatocytes preferentially align along the closest micro-vessels. Here, we studied whether this mechanism is still active in early hepatocellular tumors. The same agent-based spatiotemporal model that previously correctly predicted HSA in liver regeneration was further developed to simulate scenarios in early tumor development, when individual initiated hepatocytes gain increased proliferation capacity. The model simulations were performed under conditions of realistic liver micro-architectures obtained from 3D reconstructions of confocal laser scanning micrographs. Interestingly, the established model predicted that initiated hepatocytes at first arrange in elongated patterns. Only when the tumor progresses to cell numbers of approximately 4000, does it adopt spherical structures. This prediction may have relevant consequences, since elongated tumors may reach critical structures faster, such as larger vessels, compared to a spherical tumor of similar cell number. Interestingly, this model prediction was confirmed by analysis of the spatial organization of initiated hepatocytes in a rat liver tumor initiation study using single doses of 250 mg/kg of the genotoxic carcinogen N-nitrosomorpholine (NNM). Indeed, small clusters of GST-P positive cells induced by NNM were elongated, almost columnar, while larger GDT-P positive foci of approximately the size of liver lobuli adopted spherical shapes. From simulations testing numerous possible mechanisms, only HSA could explain the experimentally observed initial deviation from spherical shape. The present study demonstrates that the architecture of small cell clusters of hepatocytes early after initiation is still controlled by physiological mechanisms. However, this coordinating influence is lost when the tumor grows to approximately 4000 cells, leading to further growth in spherical shape. Our findings stress the potential importance of organ micro-architecture in understanding tumor phenotypes.
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35
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Ghaffarizadeh A, Heiland R, Friedman SH, Mumenthaler SM, Macklin P. PhysiCell: An open source physics-based cell simulator for 3-D multicellular systems. PLoS Comput Biol 2018; 14:e1005991. [PMID: 29474446 PMCID: PMC5841829 DOI: 10.1371/journal.pcbi.1005991] [Citation(s) in RCA: 188] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 03/07/2018] [Accepted: 01/19/2018] [Indexed: 02/07/2023] Open
Abstract
Many multicellular systems problems can only be understood by studying how cells move, grow, divide, interact, and die. Tissue-scale dynamics emerge from systems of many interacting cells as they respond to and influence their microenvironment. The ideal "virtual laboratory" for such multicellular systems simulates both the biochemical microenvironment (the "stage") and many mechanically and biochemically interacting cells (the "players" upon the stage). PhysiCell-physics-based multicellular simulator-is an open source agent-based simulator that provides both the stage and the players for studying many interacting cells in dynamic tissue microenvironments. It builds upon a multi-substrate biotransport solver to link cell phenotype to multiple diffusing substrates and signaling factors. It includes biologically-driven sub-models for cell cycling, apoptosis, necrosis, solid and fluid volume changes, mechanics, and motility "out of the box." The C++ code has minimal dependencies, making it simple to maintain and deploy across platforms. PhysiCell has been parallelized with OpenMP, and its performance scales linearly with the number of cells. Simulations up to 105-106 cells are feasible on quad-core desktop workstations; larger simulations are attainable on single HPC compute nodes. We demonstrate PhysiCell by simulating the impact of necrotic core biomechanics, 3-D geometry, and stochasticity on the dynamics of hanging drop tumor spheroids and ductal carcinoma in situ (DCIS) of the breast. We demonstrate stochastic motility, chemical and contact-based interaction of multiple cell types, and the extensibility of PhysiCell with examples in synthetic multicellular systems (a "cellular cargo delivery" system, with application to anti-cancer treatments), cancer heterogeneity, and cancer immunology. PhysiCell is a powerful multicellular systems simulator that will be continually improved with new capabilities and performance improvements. It also represents a significant independent code base for replicating results from other simulation platforms. The PhysiCell source code, examples, documentation, and support are available under the BSD license at http://PhysiCell.MathCancer.org and http://PhysiCell.sf.net.
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Affiliation(s)
- Ahmadreza Ghaffarizadeh
- Lawrence J. Ellison Institute for Transformative Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Randy Heiland
- Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
| | - Samuel H. Friedman
- Lawrence J. Ellison Institute for Transformative Medicine, University of Southern California, Los Angeles, California, United States of America
- Opto-Knowledge Systems, Inc., Torrance, California, United States of America
| | - Shannon M. Mumenthaler
- Lawrence J. Ellison Institute for Transformative Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Paul Macklin
- Lawrence J. Ellison Institute for Transformative Medicine, University of Southern California, Los Angeles, California, United States of America
- Intelligent Systems Engineering, Indiana University, Bloomington, Indiana, United States of America
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36
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Discrete and Continuum Approximations for Collective Cell Migration in a Scratch Assay with Cell Size Dynamics. Bull Math Biol 2018; 80:738-757. [DOI: 10.1007/s11538-018-0398-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 01/19/2018] [Indexed: 10/18/2022]
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37
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Creation of Three-Dimensional Liver Tissue Models from Experimental Images for Systems Medicine. Methods Mol Biol 2018; 1506:319-362. [PMID: 27830563 DOI: 10.1007/978-1-4939-6506-9_22] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In this chapter, we illustrate how three-dimensional liver tissue models can be created from experimental image modalities by utilizing a well-established processing chain of experiments, microscopic imaging, image processing, image analysis and model construction. We describe how key features of liver tissue architecture are quantified and translated into model parameterizations, and show how a systematic iteration of experiments and model simulations often leads to a better understanding of biological phenomena in systems biology and systems medicine.
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38
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Linking DNA Damage and Age-Related Promoter DNA Hyper-Methylation in the Intestine. Genes (Basel) 2018; 9:genes9010017. [PMID: 29303998 PMCID: PMC5793170 DOI: 10.3390/genes9010017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 12/21/2017] [Accepted: 12/21/2017] [Indexed: 12/22/2022] Open
Abstract
Aberrant DNA methylation in stem cells is a hallmark of aging and tumor development. Here, we explore whether and how DNA damage repair might impact on these time-dependent changes, in particular in proliferative intestinal stem cells. We introduce a 3D multiscale computer model of intestinal crypts enabling simulation of aberrant DNA and histone methylation of gene promoters during aging. We assume histone state-dependent activity of de novo DNA methyltransferases (DNMTs) and methylation-dependent binding of maintenance DNMTs to CpGs. We simulate aging with and without repeated DNA repair. Motivated by recent findings on the histone demethylase KDM2b, we consider that DNA repair is associated with chromatin opening and improved recruitment of de novo DNMTs. Our results suggest that methylation-dependent binding of maintenance DNMTs to CpGs, establishing bistable DNA methylation states, is a prerequisite to promoter hyper-methylation following DNA repair. With this, the transient increase in de novo DNMT activity during repair can induce switches from low to high methylation states. These states remain stable after repair, leading to an epigenetic drift. The switches are most frequent in genes with H3K27me3 modified promoters. Our model provides a mechanistic explanation on how even successful DNA repair might confer long term changes of the epigenome.
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39
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Almet AA, Hughes BD, Landman KA, Näthke IS, Osborne JM. A Multicellular Model of Intestinal Crypt Buckling and Fission. Bull Math Biol 2017; 80:335-359. [DOI: 10.1007/s11538-017-0377-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 12/01/2017] [Indexed: 12/11/2022]
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40
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Adhesion forces and cortical tension couple cell proliferation and differentiation to drive epidermal stratification. Nat Cell Biol 2017; 20:69-80. [PMID: 29230016 DOI: 10.1038/s41556-017-0005-z] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 10/05/2017] [Indexed: 12/22/2022]
Abstract
To establish and maintain organ structure and function, tissues need to balance stem cell proliferation and differentiation rates and coordinate cell fate with position. By quantifying and modelling tissue stress and deformation in the mammalian epidermis, we find that this balance is coordinated through local mechanical forces generated by cell division and delamination. Proliferation within the basal stem/progenitor layer, which displays features of a jammed, solid-like state, leads to crowding, thereby locally distorting cell shape and stress distribution. The resulting decrease in cortical tension and increased cell-cell adhesion trigger differentiation and subsequent delamination, reinstating basal cell layer density. After delamination, cells establish a high-tension state as they increase myosin II activity and convert to E-cadherin-dominated adhesion, thereby reinforcing the boundary between basal and suprabasal layers. Our results uncover how biomechanical signalling integrates single-cell behaviours to couple proliferation, cell fate and positioning to generate a multilayered tissue.
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41
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Wong KK. Three-dimensional discrete element method for the prediction of protoplasmic seepage through membrane in a biological cell. J Biomech 2017; 65:115-124. [DOI: 10.1016/j.jbiomech.2017.10.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/09/2017] [Accepted: 10/15/2017] [Indexed: 12/15/2022]
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42
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Materi W, Wishart DS. Computational Systems Biology in Cancer: Modeling Methods and Applications. GENE REGULATION AND SYSTEMS BIOLOGY 2017. [DOI: 10.1177/117762500700100010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In recent years it has become clear that carcinogenesis is a complex process, both at the molecular and cellular levels. Understanding the origins, growth and spread of cancer, therefore requires an integrated or system-wide approach. Computational systems biology is an emerging sub-discipline in systems biology that utilizes the wealth of data from genomic, proteomic and metabolomic studies to build computer simulations of intra and intercellular processes. Several useful descriptive and predictive models of the origin, growth and spread of cancers have been developed in an effort to better understand the disease and potential therapeutic approaches. In this review we describe and assess the practical and theoretical underpinnings of commonly-used modeling approaches, including ordinary and partial differential equations, petri nets, cellular automata, agent based models and hybrid systems. A number of computer-based formalisms have been implemented to improve the accessibility of the various approaches to researchers whose primary interest lies outside of model development. We discuss several of these and describe how they have led to novel insights into tumor genesis, growth, apoptosis, vascularization and therapy.
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Affiliation(s)
- Wayne Materi
- National Research Council, National Institute for Nanotechnology (NINT) Edmonton, Alberta, Canada
| | - David S. Wishart
- Departments of Biological Sciences and Computing Science, University of Alberta
- National Research Council, National Institute for Nanotechnology (NINT) Edmonton, Alberta, Canada
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43
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Tan RZ, Lai T, Chiam KH. The role of apical contractility in determining cell morphology in multilayered epithelial sheets and tubes. Phys Biol 2017. [PMID: 28639563 DOI: 10.1088/1478-3975/aa7afc] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A multilayered epithelium is made up of individual cells that are stratified in an orderly fashion, layer by layer. In such tissues, individual cells can adopt a wide range of shapes ranging from columnar to squamous. From histological images, we observe that, in flat epithelia such as the skin, the cells in the top layer are squamous while those in the middle and bottom layers are columnar, whereas in tubular epithelia, the cells in all layers are columnar. We develop a computational model to understand how individual cell shape is governed by the mechanical forces within multilayered flat and curved epithelia. We derive the energy function for an epithelial sheet of cells considering intercellular adhesive and intracellular contractile forces. We determine computationally the cell morphologies that minimize the energy function for a wide range of cellular parameters. Depending on the dominant adhesive and contractile forces, we find four dominant cell morphologies for the multilayered-layered flat sheet and three dominant cell morphologies for the two-layered curved sheet. We study the transitions between the dominant cell morphologies for the two-layered flat sheet and find both continuous and discontinuous transitions and also the presence of multistable states. Matching our computational results with histological images, we conclude that apical contractile forces from the actomyosin belt in the epithelial cells is the dominant force determining cell shape in multilayered epithelia. Our computational model can guide tissue engineers in designing artificial multilayered epithelia, in terms of figuring out the cellular parameters needed to achieve realistic epithelial morphologies.
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Affiliation(s)
- Rui Zhen Tan
- Bioinformatics Institute, A*STAR, Singapore, 30 Biopolis St, #07-01 Matrix, 138671, Singapore
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Szymańska Z, Cytowski M, Mitchell E, Macnamara CK, Chaplain MAJ. Computational Modelling of Cancer Development and Growth: Modelling at Multiple Scales and Multiscale Modelling. Bull Math Biol 2017. [PMID: 28634857 DOI: 10.1007/s11538-017-0292-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In this paper, we present two mathematical models related to different aspects and scales of cancer growth. The first model is a stochastic spatiotemporal model of both a synthetic gene regulatory network (the example of a three-gene repressilator is given) and an actual gene regulatory network, the NF-[Formula: see text]B pathway. The second model is a force-based individual-based model of the development of a solid avascular tumour with specific application to tumour cords, i.e. a mass of cancer cells growing around a central blood vessel. In each case, we compare our computational simulation results with experimental data. In the final discussion section, we outline how to take the work forward through the development of a multiscale model focussed at the cell level. This would incorporate key intracellular signalling pathways associated with cancer within each cell (e.g. p53-Mdm2, NF-[Formula: see text]B) and through the use of high-performance computing be capable of simulating up to [Formula: see text] cells, i.e. the tissue scale. In this way, mathematical models at multiple scales would be combined to formulate a multiscale computational model.
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Affiliation(s)
- Zuzanna Szymańska
- ICM, University of Warsaw, ul. Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Maciej Cytowski
- ICM, University of Warsaw, ul. Pawińskiego 5a, 02-106, Warsaw, Poland
| | - Elaine Mitchell
- Division of Mathematics, University of Dundee, Dundee, DD1 4HN, Scotland, UK
| | - Cicely K Macnamara
- School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS, Scotland, UK
| | - Mark A J Chaplain
- School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS, Scotland, UK.
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The Regulatory Capacity of Bivalent Genes-A Theoretical Approach. Int J Mol Sci 2017; 18:ijms18051069. [PMID: 28513551 PMCID: PMC5454979 DOI: 10.3390/ijms18051069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 02/07/2023] Open
Abstract
Bivalent genes are frequently associated with developmental and lineage specification processes. Resolving their bivalency enables fast changes in their expression, which potentially can trigger cell fate decisions. Here, we provide a theoretical model of bivalency that allows for predictions on the occurrence, stability and regulatory capacity of this prominent modification state. We suggest that bivalency enables balanced gene expression heterogeneity that constitutes a prerequisite of robust lineage priming in somatic stem cells. Moreover, we demonstrate that interactions between the histone and DNA methylation machineries together with the proliferation activity control the stability of the bivalent state and can turn it into an unmodified state. We suggest that deregulation of these interactions underlies cell transformation processes as associated with acute myeloid leukemia (AML) and provide a model of AML blast formation following deregulation of the Ten-eleven Translocation (TET) pathway.
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Nakao M, Kurashina Y, Imashiro C, Takemura K. A Method for Collecting Single Cell Suspensions Using an Ultrasonic Pump. IEEE Trans Biomed Eng 2017; 65:224-231. [PMID: 28463184 DOI: 10.1109/tbme.2017.2699291] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The presence of cell aggregates in cell suspensions may reduce cell culture efficiency because they can induce apoptosis and inhibit proliferation. To avoid this problem, this study proposes a novel method for collecting single cell suspensions from culture chambers for subculture using an ultrasonic pump driven by the squeeze film effect. First, we developed a cell culture device consisting of a cell culture substrate with a piezoelectric ceramic disk glued to the back, so that we can elicit resonance vibration of the substrate. A glass pipe is then placed vertically against the cell culture substrate with a slight gap (corresponding to cell diameter) between the pipe and the substrate. By exciting an out-of-plane resonance vibration of the cell culture substrate, we can collect a cell suspension from the cell culture chamber. Since the gap distance between the glass pipe and the cell culture substrate corresponds to cell diameter, the collected cell suspension only contains single cells. We evaluated the capability of the developed cell suspension pumping system and the proliferation of the collected cells with C2C12 myoblast cells. The ratio of single cells in the cell suspension was improved by up to 9.6% compared with that of suspensions collected by the control method (traditional pipetting). Moreover, after cultivating the collected cells for 72 hr, the cells collected by our method proliferated 13.6% more than those collected by the control method. These results suggest that the proposed method has great potential for improving the cultivation efficiency of adhesive cell culture.
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Ingham-Dempster T, Walker DC, Corfe BM. An agent-based model of anoikis in the colon crypt displays novel emergent behaviour consistent with biological observations. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160858. [PMID: 28484606 PMCID: PMC5414243 DOI: 10.1098/rsos.160858] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 03/14/2017] [Indexed: 05/07/2023]
Abstract
Colorectal cancer (CRC) is a major cause of cancer mortality. Colon crypts are multi-cellular flask-shaped invaginations of the colonic epithelium, with stem cells at their base which support the continual turnover of the epithelium with loss of cells by anoikis from the flat mucosa. Mutations in these stem cells can become embedded in the crypts, a process that is strongly implicated in CRC initiation. We describe a computational model which includes novel features, including an accurate representation of the geometry of the crypt mouth. Model simulations yield previously unseen emergent phenomena, such as localization of cell death to a small region of the crypt mouth which corresponds with that observed in vivo. A mechanism emerges in the model for regulation of crypt cellularity in response to changes in either cell proliferation rates or membrane adhesion strengths. We show that cell shape assumptions influence this behaviour, with cylinders recapitulating biology better than spheres. Potential applications of the model include determination of roles of mutations in neoplasia and exploring factors for altered crypt morphodynamics.
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Affiliation(s)
- Tim Ingham-Dempster
- Insigneo Institute for in silico medicine, Pam Liversedge Building, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, UK
- Department of Oncology and Metabolism, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
| | - Dawn C. Walker
- Insigneo Institute for in silico medicine, Pam Liversedge Building, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, UK
- Department of Computer Science, University of Sheffield, 211 Portobello, Sheffield S1 4DP, UK
| | - Bernard M. Corfe
- Insigneo Institute for in silico medicine, Pam Liversedge Building, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD, UK
- Department of Oncology and Metabolism, The Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK
- e-mail:
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Ahmadzadeh H, Webster MR, Behera R, Jimenez Valencia AM, Wirtz D, Weeraratna AT, Shenoy VB. Modeling the two-way feedback between contractility and matrix realignment reveals a nonlinear mode of cancer cell invasion. Proc Natl Acad Sci U S A 2017; 114:E1617-E1626. [PMID: 28196892 PMCID: PMC5338523 DOI: 10.1073/pnas.1617037114] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cancer cell invasion from primary tumors is mediated by a complex interplay between cellular adhesions, actomyosin-driven contractility, and the physical characteristics of the extracellular matrix (ECM). Here, we incorporate a mechanochemical free-energy-based approach to elucidate how the two-way feedback loop between cell contractility (induced by the activity of chemomechanical interactions such as Ca2+ and Rho signaling pathways) and matrix fiber realignment and strain stiffening enables the cells to polarize and develop contractile forces to break free from the tumor spheroids and invade into the ECM. Interestingly, through this computational model, we are able to identify a critical stiffness that is required by the matrix to break intercellular adhesions and initiate cell invasion. Also, by considering the kinetics of the cell movement, our model predicts a biphasic invasiveness with respect to the stiffness of the matrix. These predictions are validated by analyzing the invasion of melanoma cells in collagen matrices of varying concentration. Our model also predicts a positive correlation between the elongated morphology of the invading cells and the alignment of fibers in the matrix, suggesting that cell polarization is directly proportional to the stiffness and alignment of the matrix. In contrast, cells in nonfibrous matrices are found to be rounded and not polarized, underscoring the key role played by the nonlinear mechanics of fibrous matrices. Importantly, our model shows that mechanical principles mediated by the contractility of the cells and the nonlinearity of the ECM behavior play a crucial role in determining the phenotype of the cell invasion.
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Affiliation(s)
- Hossein Ahmadzadeh
- Department of Materials Science and Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104
| | - Marie R Webster
- Tumor Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104
| | - Reeti Behera
- Tumor Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104
| | - Angela M Jimenez Valencia
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218
- Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218
- Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218
- Physical Sciences-Oncology Center, The Johns Hopkins University, Baltimore, MD 21218
- Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD 21218
- Department of Oncology, The Johns Hopkins School of Medicine, Baltimore, MD 21218
- Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, MD 21218
| | - Ashani T Weeraratna
- Tumor Microenvironment and Metastasis Program, The Wistar Institute, Philadelphia, PA 19104
| | - Vivek B Shenoy
- Department of Materials Science and Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104;
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA 19104
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Osborne JM, Fletcher AG, Pitt-Francis JM, Maini PK, Gavaghan DJ. Comparing individual-based approaches to modelling the self-organization of multicellular tissues. PLoS Comput Biol 2017; 13:e1005387. [PMID: 28192427 PMCID: PMC5330541 DOI: 10.1371/journal.pcbi.1005387] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 02/28/2017] [Accepted: 01/28/2017] [Indexed: 12/28/2022] Open
Abstract
The coordinated behaviour of populations of cells plays a central role in tissue growth and renewal. Cells react to their microenvironment by modulating processes such as movement, growth and proliferation, and signalling. Alongside experimental studies, computational models offer a useful means by which to investigate these processes. To this end a variety of cell-based modelling approaches have been developed, ranging from lattice-based cellular automata to lattice-free models that treat cells as point-like particles or extended shapes. However, it remains unclear how these approaches compare when applied to the same biological problem, and what differences in behaviour are due to different model assumptions and abstractions. Here, we exploit the availability of an implementation of five popular cell-based modelling approaches within a consistent computational framework, Chaste (http://www.cs.ox.ac.uk/chaste). This framework allows one to easily change constitutive assumptions within these models. In each case we provide full details of all technical aspects of our model implementations. We compare model implementations using four case studies, chosen to reflect the key cellular processes of proliferation, adhesion, and short- and long-range signalling. These case studies demonstrate the applicability of each model and provide a guide for model usage.
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Affiliation(s)
- James M. Osborne
- School of Mathematics and Statistics, University of Melbourne, Parkville, Victoria, Australia
| | - Alexander G. Fletcher
- School of Mathematics and Statistics, University of Sheffield, Sheffield, United Kingdom
- Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Joe M. Pitt-Francis
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
| | - Philip K. Maini
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | - David J. Gavaghan
- Department of Computer Science, University of Oxford, Oxford, United Kingdom
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Discrete Mesh Approach in Morphogenesis Modelling: the Example of Gastrulation. Acta Biotheor 2016; 64:427-446. [PMID: 27853896 DOI: 10.1007/s10441-016-9301-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 10/19/2016] [Indexed: 10/20/2022]
Abstract
Morphogenesis is a general concept in biology including all the processes which generate tissue shapes and cellular organizations in a living organism. Many hybrid formalizations (i.e., with both discrete and continuous parts) have been proposed for modelling morphogenesis in embryonic or adult animals, like gastrulation. We propose first to study the ventral furrow invagination as the initial step of gastrulation, early stage of embryogenesis. We focus on the study of the connection between the apical constriction of the ventral cells and the initiation of the invagination. For that, we have created a 3D biomechanical model of the embryo of the Drosophila melanogaster based on the finite element method. Each cell is modelled by an elastic hexahedron contour and is firmly attached to its neighbouring cells. A uniform initial distribution of elastic and contractile forces is applied to cells along the model. Numerical simulations show that invagination starts at ventral curved extremities of the embryo and then propagates to the ventral medial layer. Then, this observation already made in some experiments can be attributed uniquely to the specific shape of the embryo and we provide mechanical evidence to support it. Results of the simulations of the "pill-shaped" geometry of the Drosophila melanogaster embryo are compared with those of a spherical geometry corresponding to the Xenopus lævis embryo. Eventually, we propose to study the influence of cell proliferation on the end of the process of invagination represented by the closure of the ventral furrow.
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