1
|
Heyn JCJ, Rädler JO, Falcke M. Mesenchymal cell migration on one-dimensional micropatterns. Front Cell Dev Biol 2024; 12:1352279. [PMID: 38694822 PMCID: PMC11062138 DOI: 10.3389/fcell.2024.1352279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/29/2024] [Indexed: 05/04/2024] Open
Abstract
Quantitative studies of mesenchymal cell motion are important to elucidate cytoskeleton function and mechanisms of cell migration. To this end, confinement of cell motion to one dimension (1D) significantly simplifies the problem of cell shape in experimental and theoretical investigations. Here we review 1D migration assays employing micro-fabricated lanes and reflect on the advantages of such platforms. Data are analyzed using biophysical models of cell migration that reproduce the rich scenario of morphodynamic behavior found in 1D. We describe basic model assumptions and model behavior. It appears that mechanical models explain the occurrence of universal relations conserved across different cell lines such as the adhesion-velocity relation and the universal correlation between speed and persistence (UCSP). We highlight the unique opportunity of reproducible and standardized 1D assays to validate theory based on statistical measures from large data of trajectories and discuss the potential of experimental settings embedding controlled perturbations to probe response in migratory behavior.
Collapse
Affiliation(s)
- Johannes C. J. Heyn
- Fakultät für Physik, Ludwig-Maximilians-Universität München (LMU), Munich, Germany
| | - Joachim O. Rädler
- Fakultät für Physik, Ludwig-Maximilians-Universität München (LMU), Munich, Germany
| | - Martin Falcke
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- Department of Physics, Humboldt University, Berlin, Germany
| |
Collapse
|
2
|
Brückner DB, Broedersz CP. Learning dynamical models of single and collective cell migration: a review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:056601. [PMID: 38518358 DOI: 10.1088/1361-6633/ad36d2] [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: 10/07/2023] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
Single and collective cell migration are fundamental processes critical for physiological phenomena ranging from embryonic development and immune response to wound healing and cancer metastasis. To understand cell migration from a physical perspective, a broad variety of models for the underlying physical mechanisms that govern cell motility have been developed. A key challenge in the development of such models is how to connect them to experimental observations, which often exhibit complex stochastic behaviours. In this review, we discuss recent advances in data-driven theoretical approaches that directly connect with experimental data to infer dynamical models of stochastic cell migration. Leveraging advances in nanofabrication, image analysis, and tracking technology, experimental studies now provide unprecedented large datasets on cellular dynamics. In parallel, theoretical efforts have been directed towards integrating such datasets into physical models from the single cell to the tissue scale with the aim of conceptualising the emergent behaviour of cells. We first review how this inference problem has been addressed in both freely migrating and confined cells. Next, we discuss why these dynamics typically take the form of underdamped stochastic equations of motion, and how such equations can be inferred from data. We then review applications of data-driven inference and machine learning approaches to heterogeneity in cell behaviour, subcellular degrees of freedom, and to the collective dynamics of multicellular systems. Across these applications, we emphasise how data-driven methods can be integrated with physical active matter models of migrating cells, and help reveal how underlying molecular mechanisms control cell behaviour. Together, these data-driven approaches are a promising avenue for building physical models of cell migration directly from experimental data, and for providing conceptual links between different length-scales of description.
Collapse
Affiliation(s)
- David B Brückner
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | - Chase P Broedersz
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilian-University Munich, Theresienstr. 37, D-80333 Munich, Germany
| |
Collapse
|
3
|
Sadhu RK, Luciano M, Xi W, Martinez-Torres C, Schröder M, Blum C, Tarantola M, Villa S, Penič S, Iglič A, Beta C, Steinbock O, Bodenschatz E, Ladoux B, Gabriele S, Gov NS. A minimal physical model for curvotaxis driven by curved protein complexes at the cell's leading edge. Proc Natl Acad Sci U S A 2024; 121:e2306818121. [PMID: 38489386 PMCID: PMC10963004 DOI: 10.1073/pnas.2306818121] [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: 04/27/2023] [Accepted: 01/29/2024] [Indexed: 03/17/2024] Open
Abstract
Cells often migrate on curved surfaces inside the body, such as curved tissues, blood vessels, or highly curved protrusions of other cells. Recent in vitro experiments provide clear evidence that motile cells are affected by the curvature of the substrate on which they migrate, preferring certain curvatures to others, termed "curvotaxis." The origin and underlying mechanism that gives rise to this curvature sensitivity are not well understood. Here, we employ a "minimal cell" model which is composed of a vesicle that contains curved membrane protein complexes, that exert protrusive forces on the membrane (representing the pressure due to actin polymerization). This minimal-cell model gives rise to spontaneous emergence of a motile phenotype, driven by a lamellipodia-like leading edge. By systematically screening the behavior of this model on different types of curved substrates (sinusoidal, cylinder, and tube), we show that minimal ingredients and energy terms capture the experimental data. The model recovers the observed migration on the sinusoidal substrate, where cells move along the grooves (minima), while avoiding motion along the ridges. In addition, the model predicts the tendency of cells to migrate circumferentially on convex substrates and axially on concave ones. Both of these predictions are verified experimentally, on several cell types. Altogether, our results identify the minimization of membrane-substrate adhesion energy and binding energy between the membrane protein complexes as key players of curvotaxis in cell migration.
Collapse
Affiliation(s)
- Raj Kumar Sadhu
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| | - Marine Luciano
- Department of Biochemistry, University of Geneva, Geneva4 CH-1211, Switzerland
- Mechanobiology & Biomaterials Group, Research Institute for Biosciences, Center of Innovation and Research in Materials and Polymers, University of Mons, MonsB-7000, Belgium
| | - Wang Xi
- Universite Paris Cite, CNRS, Institut Jacques Monod, ParisF-75013, France
| | | | - Marcel Schröder
- Department of Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen37077, Germany
| | - Christoph Blum
- Department of Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen37077, Germany
| | - Marco Tarantola
- Department of Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen37077, Germany
| | - Stefano Villa
- Department of Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen37077, Germany
| | - Samo Penič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana1000, Slovenia
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana1000, Slovenia
| | - Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, Potsdam14476, Germany
- Nano Life Science Institute, Kanazawa University, Kanazawa920-1192, Japan
| | - Oliver Steinbock
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL32306-4390
| | - Eberhard Bodenschatz
- Department of Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen37077, Germany
| | - Benoît Ladoux
- Universite Paris Cite, CNRS, Institut Jacques Monod, ParisF-75013, France
| | - Sylvain Gabriele
- Mechanobiology & Biomaterials Group, Research Institute for Biosciences, Center of Innovation and Research in Materials and Polymers, University of Mons, MonsB-7000, Belgium
| | - Nir S. Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot7610001, Israel
| |
Collapse
|
4
|
Gao X, Hou T, Wang L, Liu Y, Guo J, Zhang L, Yang T, Tang W, An M, Wen M. Aligned electrospun fibers of different diameters for improving cell migration capacity. Colloids Surf B Biointerfaces 2024; 234:113674. [PMID: 38039823 DOI: 10.1016/j.colsurfb.2023.113674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 10/27/2023] [Accepted: 11/24/2023] [Indexed: 12/03/2023]
Abstract
Electrospun fibers have gained significant attention as scaffolds in skin tissue engineering due to their biomimetic properties, which resemble the fibrous extracellular matrix. The morphological characteristics of electrospun fibers play a crucial role in determining cell behavior. However, the effects of electrospun fibers' arrangement and diameters on human skin fibroblasts (HSFs) remain elusive. Here, we revealed the impact of electrospun fiber diameters (700 nm, 2000 nm, and 3000 nm) on HSFs' proliferation, migration, and functional expression. The results demonstrated that all fibers exhibited good cytocompatibility. HSFs cultured on nanofibers (700 nm diameter) displayed a more dispersed and elongated morphology. Conversely, fibers with a diameter of 3000 nm exhibited a reduced specific surface area and lower adsorption of adhesion proteins, resulting in enhanced cell migration speed and effective migration rate. Meanwhile, the expression levels of migration-related genes and proteins were upregulated at 48 h for the 3000 nm fibers. This study demonstrated the unique role of fiber diameters in controlling the physiological functions of cells, especially decision-making and navigating migration in complex microenvironments of aligned electrospun fibers, and highlights the utility of these bioactive substitutes in skin tissue engineering applications.
Collapse
Affiliation(s)
- Xiang Gao
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Tian Hou
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Li Wang
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Yang Liu
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Jiqiang Guo
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Li Zhang
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, Shanxi 030032, China; Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Tiantian Yang
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Wenjie Tang
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China
| | - Meiwen An
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China.
| | - Meiling Wen
- Institute of Biomedical Engineering, College of Biomedical Engineering, Taiyuan University of Technology, Shanxi Key Laboratory of Material Strength & Structural Impact, Taiyuan, Shanxi 030024, China.
| |
Collapse
|
5
|
Tagay Y, Kheirabadi S, Ataie Z, Singh RK, Prince O, Nguyen A, Zhovmer AS, Ma X, Sheikhi A, Tsygankov D, Tabdanov ED. Dynein-Powered Cell Locomotion Guides Metastasis of Breast Cancer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302229. [PMID: 37726225 PMCID: PMC10625109 DOI: 10.1002/advs.202302229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 08/20/2023] [Indexed: 09/21/2023]
Abstract
The principal cause of death in cancer patients is metastasis, which remains an unresolved problem. Conventionally, metastatic dissemination is linked to actomyosin-driven cell locomotion. However, the locomotion of cancer cells often does not strictly line up with the measured actomyosin forces. Here, a complementary mechanism of metastatic locomotion powered by dynein-generated forces is identified. These forces arise within a non-stretchable microtubule network and drive persistent contact guidance of migrating cancer cells along the biomimetic collagen fibers. It is also shown that the dynein-powered locomotion becomes indispensable during invasive 3D migration within a tissue-like luminal network formed by spatially confining granular hydrogel scaffolds (GHS) made up of microscale hydrogel particles (microgels). These results indicate that the complementary motricity mediated by dynein is always necessary and, in certain instances, sufficient for disseminating metastatic breast cancer cells. These findings advance the fundamental understanding of cell locomotion mechanisms and expand the spectrum of clinical targets against metastasis.
Collapse
Affiliation(s)
- Yerbol Tagay
- Department of PharmacologyPenn State College of MedicineThe Pennsylvania State UniversityHersheyPA17033USA
| | - Sina Kheirabadi
- Department of Chemical EngineeringThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Zaman Ataie
- Department of Chemical EngineeringThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Rakesh K. Singh
- Department of Obstetrics & GynecologyGynecology OncologyUniversity of Rochester Medical CenterRochesterNY14642USA
| | - Olivia Prince
- Center for Biologics Evaluation and ResearchU.S. Food and Drug AdministrationSilver SpringMD20903USA
| | - Ashley Nguyen
- Center for Biologics Evaluation and ResearchU.S. Food and Drug AdministrationSilver SpringMD20903USA
| | - Alexander S. Zhovmer
- Center for Biologics Evaluation and ResearchU.S. Food and Drug AdministrationSilver SpringMD20903USA
| | - Xuefei Ma
- Center for Biologics Evaluation and ResearchU.S. Food and Drug AdministrationSilver SpringMD20903USA
| | - Amir Sheikhi
- Department of Chemical EngineeringThe Pennsylvania State UniversityUniversity ParkPA16802USA
- Department of Biomedical EngineeringThe Pennsylvania State UniversityUniversity ParkPA16802USA
| | - Denis Tsygankov
- Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory UniversityAtlantaGA30332USA
| | - Erdem D. Tabdanov
- Department of PharmacologyPenn State College of MedicineThe Pennsylvania State UniversityHersheyPA17033USA
- Penn State Cancer InstitutePenn State College of MedicineThe Pennsylvania State UniversityHersheyPA17033USA
| |
Collapse
|
6
|
Sadhu RK, Hernandez-Padilla C, Eisenbach YE, Penič S, Zhang L, Vishwasrao HD, Behkam B, Konstantopoulos K, Shroff H, Iglič A, Peles E, Nain AS, Gov NS. Experimental and theoretical model for the origin of coiling of cellular protrusions around fibers. Nat Commun 2023; 14:5612. [PMID: 37699891 PMCID: PMC10497540 DOI: 10.1038/s41467-023-41273-y] [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: 08/26/2022] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Protrusions at the leading-edge of a cell play an important role in sensing the extracellular cues during cellular spreading and motility. Recent studies provided indications that these protrusions wrap (coil) around the extracellular fibers. However, the physics of this coiling process, and the mechanisms that drive it, are not well understood. We present a combined theoretical and experimental study of the coiling of cellular protrusions on fibers of different geometry. Our theoretical model describes membrane protrusions that are produced by curved membrane proteins that recruit the protrusive forces of actin polymerization, and identifies the role of bending and adhesion energies in orienting the leading-edges of the protrusions along the azimuthal (coiling) direction. Our model predicts that the cell's leading-edge coils on fibers with circular cross-section (above some critical radius), but the coiling ceases for flattened fibers of highly elliptical cross-section. These predictions are verified by 3D visualization and quantitation of coiling on suspended fibers using Dual-View light-sheet microscopy (diSPIM). Overall, we provide a theoretical framework, supported by experiments, which explains the physical origin of the coiling phenomenon.
Collapse
Affiliation(s)
- Raj Kumar Sadhu
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
- Institut Curie, PSL Research University, CNRS, UMR 168, Paris, France.
| | | | - Yael Eshed Eisenbach
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Samo Penič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Lixia Zhang
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Harshad D Vishwasrao
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
| | - Bahareh Behkam
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | | | - Hari Shroff
- Advanced Imaging and Microscopy Resource, National Institutes of Health, Bethesda, MD, USA
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, USA
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
| | - Elior Peles
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Amrinder S Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Nir S Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel.
| |
Collapse
|
7
|
Alonso-Matilla R, Provenzano PP, Odde DJ. Optimal cell traction forces in a generalized motor-clutch model. Biophys J 2023; 122:3369-3385. [PMID: 37475213 PMCID: PMC10465728 DOI: 10.1016/j.bpj.2023.07.012] [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: 02/20/2023] [Revised: 06/25/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023] Open
Abstract
Cells exert forces on mechanically compliant environments to sense stiffness, migrate, and remodel tissue. Cells can sense environmental stiffness via myosin-generated pulling forces acting on F-actin, which is in turn mechanically coupled to the environment via adhesive proteins, akin to a clutch in a drivetrain. In this "motor-clutch" framework, the force transmitted depends on the complex interplay of motor, clutch, and environmental properties. Previous mean-field analysis of the motor-clutch model identified the conditions for optimal stiffness for maximal force transmission via a dimensionless number that combines motor-clutch parameters. However, in this and other previous mean-field analyses, the motor-clutch system is assumed to have balanced motors and clutches and did not consider force-dependent clutch reinforcement and catch bond behavior. Here, we generalize the motor-clutch analytical framework to include imbalanced motor-clutch regimes, with clutch reinforcement and catch bonding, and investigate optimality with respect to all parameters. We found that traction force is strongly influenced by clutch stiffness, and we discovered an optimal clutch stiffness that maximizes traction force, suggesting that cells could tune their clutch mechanical properties to perform a specific function. The results provide guidance for maximizing the accuracy of cell-generated force measurements via molecular tension sensors by designing their mechanosensitive linker peptide to be as stiff as possible. In addition, we found that, on rigid substrates, the mean-field analysis identifies optimal motor properties, suggesting that cells could regulate their myosin repertoire and activity to maximize force transmission. Finally, we found that clutch reinforcement shifts the optimum substrate stiffness to larger values, whereas the optimum substrate stiffness is insensitive to clutch catch bond properties. Overall, our work reveals novel features of the motor-clutch model that can affect the design of molecular tension sensors and provide a generalized analytical framework for predicting and controlling cell adhesion and migration in immunotherapy and cancer.
Collapse
Affiliation(s)
- Roberto Alonso-Matilla
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota
| | - Paolo P Provenzano
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota; Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota; Department of Hematology, Oncology, and Transplantation, University of Minnesota, Minneapolis, Minnesota; Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - David J Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota; Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
| |
Collapse
|
8
|
Sadhu RK, Iglič A, Gov NS. A minimal cell model for lamellipodia-based cellular dynamics and migration. J Cell Sci 2023; 136:jcs260744. [PMID: 37497740 DOI: 10.1242/jcs.260744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023] Open
Abstract
One ubiquitous cellular structure for performing various tasks, such as spreading and migration over external surfaces, is the sheet-like protrusion called a lamellipodium, which propels the leading edge of the cell. Despite the detailed knowledge about the many components of this cellular structure, it is not yet fully understood how these components self-organize spatiotemporally to form lamellipodia. We review here recent theoretical works where we have demonstrated that membrane-bound protein complexes that have intrinsic curvature and recruit the protrusive forces of the cytoskeleton result in a simple, yet highly robust, organizing feedback mechanism that organizes the cytoskeleton and the membrane. This self-organization mechanism accounts for the formation of flat lamellipodia at the leading edge of cells spreading over adhesive substrates, allowing for the emergence of a polarized, motile 'minimal cell' model. The same mechanism describes how lamellipodia organize to drive robust engulfment of particles during phagocytosis and explains in simple physical terms the spreading and migration of cells over fibers and other curved surfaces. This Review highlights that despite the complexity of cellular composition, there might be simple general physical principles that are utilized by the cell to drive cellular shape dynamics.
Collapse
Affiliation(s)
- Raj Kumar Sadhu
- Institut Curie, PSL Research University, CNRS, UMR 168, Paris 75005, France
| | - Aleš Iglič
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Nir S Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| |
Collapse
|
9
|
Beta C, Edelstein-Keshet L, Gov N, Yochelis A. From actin waves to mechanism and back: How theory aids biological understanding. eLife 2023; 12:e87181. [PMID: 37428017 DOI: 10.7554/elife.87181] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/01/2023] [Indexed: 07/11/2023] Open
Abstract
Actin dynamics in cell motility, division, and phagocytosis is regulated by complex factors with multiple feedback loops, often leading to emergent dynamic patterns in the form of propagating waves of actin polymerization activity that are poorly understood. Many in the actin wave community have attempted to discern the underlying mechanisms using experiments and/or mathematical models and theory. Here, we survey methods and hypotheses for actin waves based on signaling networks, mechano-chemical effects, and transport characteristics, with examples drawn from Dictyostelium discoideum, human neutrophils, Caenorhabditis elegans, and Xenopus laevis oocytes. While experimentalists focus on the details of molecular components, theorists pose a central question of universality: Are there generic, model-independent, underlying principles, or just boundless cell-specific details? We argue that mathematical methods are equally important for understanding the emergence, evolution, and persistence of actin waves and conclude with a few challenges for future studies.
Collapse
Affiliation(s)
- Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany
| | | | - Nir Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Arik Yochelis
- Swiss Institute for Dryland Environmental and Energy Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, Israel
- Department of Physics, Ben-Gurion University of the Negev, Be'er Sheva, Israel
| |
Collapse
|
10
|
Rafnsdóttir ÓB, Kiuru A, Tebäck M, Friberg N, Revstedt P, Zhu J, Thomasson S, Czopek A, Malakpour-Permlid A, Weber T, Oredsson S. A new animal product free defined medium for 2D and 3D culturing of normal and cancer cells to study cell proliferation and migration as well as dose response to chemical treatment. Toxicol Rep 2023; 10:509-520. [PMID: 37396848 PMCID: PMC10313884 DOI: 10.1016/j.toxrep.2023.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/23/2023] [Accepted: 04/05/2023] [Indexed: 07/04/2023] Open
Abstract
Cell culturing methods are increasingly used to reduce and replace the use of live animals in biomedical research and chemical toxicity testing. Although live animals are avoided when using cell culturing methods, they often contain animal-derived components of which one of the most commonly used is foetal bovine serum (FBS). FBS is added to cell culture media among other supplements to support cell attachment/spreading and cell proliferation. The safety, batch-to-batch variation, and ethical problems with FBS are acknowledged and therefore world-wide efforts are ongoing to produce FBS free media. Here, we present the composition of a new defined medium with only human proteins either recombinant or derived from human tissues. This defined medium supports long-term culturing/routine culturing of normal cells and of cancer cells, and can be used for freezing and thawing of cells, i.e. for cell banking. Here, we show for our defined medium, growth curves and dose response curves of cells grown in two and three dimensions, and applications such as cell migration. Cell morphology was studied in real time by phase contrast and phase holographic microscopy time-lapse imaging. The cell lines used are human cancer-associated fibroblasts, keratinocytes, breast cancer JIMT-1 and MDA-MB-231 cells, colon cancer CaCo-2 cells, and pancreatic cancer MiaPaCa-2 cells as well as the mouse L929 cell line. In conclusion, we present the composition of a defined medium without animal-derived products which can be used for routine culturing and in experimental settings for normal cells and for cancer cells, i.e. our defined medium provides a leap towards a universal animal product free cell culture medium.
Collapse
Affiliation(s)
- Ólöf Birna Rafnsdóttir
- Department of Biology, Lund University, 22362 Lund, Sweden
- Institute of Life and Environmental Sciences, School of Engineering and Natural Sciences, University of Iceland, 101 Reykjavík, Iceland
| | - Anna Kiuru
- Department of Biology, Lund University, 22362 Lund, Sweden
- Occupational and Environmental Dermatology, Skåne University Hospital, 214 28 Malmö, Sweden
| | - Mattis Tebäck
- Department of Biology, Lund University, 22362 Lund, Sweden
| | | | | | - Johan Zhu
- Department of Biology, Lund University, 22362 Lund, Sweden
- Clinical Microbiology and Infection Prevention and Control, Region Skåne, 221 85 Lund, Sweden
| | - Sofia Thomasson
- Department of Biology, Lund University, 22362 Lund, Sweden
- Atos Medical AB, 242 35 Hörby, Sweden
| | | | - Atena Malakpour-Permlid
- Department of Biology, Lund University, 22362 Lund, Sweden
- Center for Intelligent Drug Delivery and Sensing Using Microcontainers and Nanomechanics, Department of Health Technology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Tilo Weber
- Animal Welfare Academy of the German Animal Welfare Federation, 85579 Neubiberg, Germany
| | - Stina Oredsson
- Department of Biology, Lund University, 22362 Lund, Sweden
| |
Collapse
|
11
|
Tagay Y, Kheirabadi S, Ataie Z, Singh RK, Prince O, Nguyen A, Zhovmer AS, Ma X, Sheikhi A, Tsygankov D, Tabdanov ED. Dynein-Powered Cell Locomotion Guides Metastasis of Breast Cancer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.04.535605. [PMID: 37066378 PMCID: PMC10104034 DOI: 10.1101/2023.04.04.535605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Metastasis is a principal cause of death in cancer patients, which remains an unresolved fundamental and clinical problem. Conventionally, metastatic dissemination is linked to the actomyosin-driven cell locomotion. However, locomotion of cancer cells often does not strictly line up with the measured actomyosin forces. Here, we identify a complementary mechanism of metastatic locomotion powered by the dynein-generated forces. These forces that arise within a non-stretchable microtubule network drive persistent contact guidance of migrating cancer cells along the biomimetic collagen fibers. We also show that dynein-powered locomotion becomes indispensable during invasive 3D migration within a tissue-like luminal network between spatially confining hydrogel microspheres. Our results indicate that the complementary contractile system of dynein motors and microtubules is always necessary and in certain instances completely sufficient for dissemination of metastatic breast cancer cells. These findings advance fundamental understanding of cell locomotion mechanisms and expand the spectrum of clinical targets against metastasis.
Collapse
Affiliation(s)
- Yerbol Tagay
- Department of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Sina Kheirabadi
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Zaman Ataie
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Rakesh K. Singh
- Department of Obstetrics & Gynecology, University of Rochester Medical Center, Rochester, NY, USA
| | - Olivia Prince
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Ashley Nguyen
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Alexander S. Zhovmer
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Xuefei Ma
- Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20903, USA
| | - Amir Sheikhi
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Denis Tsygankov
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, 30332, USA
| | - Erdem D. Tabdanov
- Department of Pharmacology, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
- Penn State Cancer Institute, Penn State College of Medicine, The Pennsylvania State University, Hershey, PA, 17033, USA
| |
Collapse
|
12
|
Bowers DT, McCulloch ME, Brown JL. Evaluation of focal adhesion mediated subcellular curvature sensing in response to engineered extracellular matrix. Biointerphases 2023; 18:021004. [PMID: 37019799 PMCID: PMC10079328 DOI: 10.1116/6.0002440] [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: 12/19/2022] [Revised: 02/24/2023] [Accepted: 03/14/2023] [Indexed: 04/07/2023] Open
Abstract
Fibril curvature is bioinstructive to attached cells. Similar to natural healthy tissues, an engineered extracellular matrix can be designed to stimulate cells to adopt desired phenotypes. To take full advantage of the curvature control in biomaterial fabrication methodologies, an understanding of the response to fibril subcellular curvature is required. In this work, we examined morphology, signaling, and function of human cells attached to electrospun nanofibers. We controlled curvature across an order of magnitude using nondegradable poly(methyl methacrylate) (PMMA) attached to a stiff substrate with flat PMMA as a control. Focal adhesion length and the distance of maximum intensity from the geographic center of the vinculin positive focal adhesion both peaked at a fiber curvature of 2.5 μm-1 (both ∼2× the flat surface control). Vinculin experienced slightly less tension when attached to nanofiber substrates. Vinculin expression was also more affected by a subcellular curvature than structural proteins α-tubulin or α-actinin. Among the phosphorylation sites we examined (FAK397, 576/577, 925, and Src416), FAK925 exhibited the most dependance on the nanofiber curvature. A RhoA/ROCK dependance of migration velocity across curvatures combined with an observation of cell membrane wrapping around nanofibers suggested a hybrid of migration modes for cells attached to fibers as has been observed in 3D matrices. Careful selection of nanofiber curvature for regenerative engineering scaffolds and substrates used to study cell biology is required to maximize the potential of these techniques for scientific exploration and ultimately improvement of human health.
Collapse
Affiliation(s)
- Daniel T. Bowers
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Mary Elizabeth McCulloch
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Justin L. Brown
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
13
|
Hashimoto N, Kitai R, Fujita S, Yamauchi T, Isozaki M, Kikuta KI. Single-Cell Analysis of Unidirectional Migration of Glioblastoma Cells Using a Fiber-Based Scaffold. ACS APPLIED BIO MATERIALS 2023; 6:765-773. [PMID: 36758146 PMCID: PMC9945112 DOI: 10.1021/acsabm.2c00958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Glioblastoma (GBM) is a malignant incurable brain tumor in which immature neoplastic cells infiltrate brain tissue by spreading along nerve fibers. The aim of the study was to compare the migration abilities of glioma cells with those of other cancer cells and elucidate the migratory profiles underlying the differential migration of glioma cells using a fiber-based quantitative migration assay. Here, wound healing and transwell assays were used to assess cell mobility in four cell lines: U87-MG glioblastoma cells, MDA-MB-231 breast cancer cells, HCT116 colorectal cancer cells, and MKN45 gastric cancer cells. We also assessed cell mobility using a fiber model that mimics nerve fibers. Time-lapse video microscopy was used to observe cell migration and morphology. The cytoskeleton arrangement was assessed in the fiber model and compared with that in the conventional cell culture model. The conventional evaluation of cell migration ability revealed that the migration ability of breast cancer and glioblastoma cell lines was higher than that of colon cancer and gastric cancer cell lines. The fiber model confirmed that the glioblastoma cell line had a significantly higher migration ability than other cell lines. Tubulin levels were significantly higher in the glioblastoma cells than in other cell lines. In conclusion, the developed fiber-based culture model revealed the specific migratory profile of GBM cells during invasion.
Collapse
Affiliation(s)
- Norichika Hashimoto
- Division of Medicine, Department of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.,Department of Neurosurgery, Fukui General Hospital, 58-16-1 Egami-cho, Fukui-shi, Fukui 910-8561, Japan
| | - Ryuhei Kitai
- Division of Medicine, Department of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.,Department of Neurosurgery, Kaga Medical Center, Kaga, Ri 36, Sakumi-machi, Kaga-shi, Ishikawa 922-8522, Japan
| | - Satoshi Fujita
- Department of Frontier Fiber Technology and Science, Graduate School of Engineering, University of Fukui, 3-9-1, Bunkyo, Fukui-shi, Fukui 910-8507, Japan.,Organization for Life Science Advancement Programs, University of Fukui, 3-9-1, Bunkyo, Fukui-shi, Fukui 910-8507, Japan
| | - Takahiro Yamauchi
- Division of Medicine, Department of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.,Organization for Life Science Advancement Programs, University of Fukui, 3-9-1, Bunkyo, Fukui-shi, Fukui 910-8507, Japan
| | - Makoto Isozaki
- Division of Medicine, Department of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan
| | - Ken-Ichiro Kikuta
- Division of Medicine, Department of Neurosurgery, Faculty of Medical Sciences, University of Fukui, 23-3, Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.,Organization for Life Science Advancement Programs, University of Fukui, 3-9-1, Bunkyo, Fukui-shi, Fukui 910-8507, Japan
| |
Collapse
|
14
|
Crestani M, Dini T, Gauthier NC, Monzo P. Protocol to assess human glioma propagating cell migration on linear micropatterns mimicking brain invasion tracks. STAR Protoc 2022; 3:101331. [PMID: 35496779 PMCID: PMC9043773 DOI: 10.1016/j.xpro.2022.101331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glioblastoma (GBM) cells invade the brain by following linear structures like blood vessel walls and white matter tracts by using specific motility modes. In this protocol, we describe two micropatterning techniques allowing recapitulation of these linear tracks in vitro: micro-contact printing and deep UV photolithography. We also detail how to maintain, transfect, and prepare human glioma propagating cells (hGPCs) for migration assays on linear tracks, followed by image acquisition and analysis, to measure key parameters of their motility. For complete details on the use and execution of this protocol, please refer to Monzo et al. (2016) and Monzo et al. (2021a). Micropatterning of linear tracks on imaging dishes Maintenance and preparation of human glioma propagating cells (hGPC) for transfection Transfection of hGPC by electroporation and preparation for imaging Imaging of hGPC migration on linear tracks, cell tracking, and analysis
Collapse
Affiliation(s)
- Michele Crestani
- IFOM - the Firc Institute of Molecular Oncology, Via Adamello, 16, 20139 Milan, Italy
| | - Tania Dini
- IFOM - the Firc Institute of Molecular Oncology, Via Adamello, 16, 20139 Milan, Italy
| | - Nils C. Gauthier
- IFOM - the Firc Institute of Molecular Oncology, Via Adamello, 16, 20139 Milan, Italy
- Corresponding author
| | - Pascale Monzo
- IFOM - the Firc Institute of Molecular Oncology, Via Adamello, 16, 20139 Milan, Italy
- Corresponding author
| |
Collapse
|
15
|
Engineered barriers regulate osteoblast cell migration in vertical direction. Sci Rep 2022; 12:4459. [PMID: 35292702 PMCID: PMC8924172 DOI: 10.1038/s41598-022-08262-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/01/2022] [Indexed: 11/29/2022] Open
Abstract
Considering cell migration is essential for understanding physiological processes and diseases. The vertical migration of cells in three dimensions is vital, but most previous studies on cell migration have only focused on two-dimensional horizontal migration. In this paper, cell migration in the vertical direction was studied. Barriers with a height of 1, 5, 10, and 25 µm with grating and arrows in channels as guiding patterns were fabricated. The effects of barrier height and guiding patterns on the vertical migration of MC3T3 cells were explored. The study revealed that taller barriers hinder vertical migration of MC3T3 cells, whereas grating and arrows in channels promote it. The time-lapse and micrograph images showed that as the barrier height increased, the cell climbing angle along the barrier sidewall decreased, and the time taken to climb over the barrier increased. These results indicate that taller barriers increase the difficulty of vertical migration by MC3T3 cells. To promote the vertical migration of MC3T3 cells, 10 µm tall barriers with 18° and 40° sloped sidewalls were fabricated. For barriers with 18° sloped sidewalls, the probability for MC3T3 cells to climb up and down the 10 µm tall barriers was 40.6% and 20.3%, respectively; this is much higher than the migration probability over vertical barriers. This study shows topographic guidance on the vertical migration of MC3T3 cells and broadens the understanding of cell migration in the vertical direction.
Collapse
|
16
|
Dynamics of Endothelial Engagement and Filopodia Formation in Complex 3D Microscaffolds. Int J Mol Sci 2022; 23:ijms23052415. [PMID: 35269558 PMCID: PMC8910162 DOI: 10.3390/ijms23052415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/08/2022] [Accepted: 02/16/2022] [Indexed: 11/28/2022] Open
Abstract
The understanding of endothelium–extracellular matrix interactions during the initiation of new blood vessels is of great medical importance; however, the mechanobiological principles governing endothelial protrusive behaviours in 3D microtopographies remain imperfectly understood. In blood capillaries submitted to angiogenic factors (such as vascular endothelial growth factor, VEGF), endothelial cells can transiently transdifferentiate in filopodia-rich cells, named tip cells, from which angiogenesis processes are locally initiated. This protrusive state based on filopodia dynamics contrasts with the lamellipodia-based endothelial cell migration on 2D substrates. Using two-photon polymerization, we generated 3D microstructures triggering endothelial phenotypes evocative of tip cell behaviour. Hexagonal lattices on pillars (“open”), but not “closed” hexagonal lattices, induced engagement from the endothelial monolayer with the generation of numerous filopodia. The development of image analysis tools for filopodia tracking allowed to probe the influence of the microtopography (pore size, regular vs. elongated structures, role of the pillars) on orientations, engagement and filopodia dynamics, and to identify MLCK (myosin light-chain kinase) as a key player for filopodia-based protrusive mode. Importantly, these events occurred independently of VEGF treatment, suggesting that the observed phenotype was induced through microtopography. These microstructures are proposed as a model research tool for understanding endothelial cell behaviour in 3D fibrillary networks.
Collapse
|
17
|
Adaptive mechanoproperties mediated by the formin FMN1 characterize glioblastoma fitness for invasion. Dev Cell 2021; 56:2841-2855.e8. [PMID: 34559979 DOI: 10.1016/j.devcel.2021.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 07/23/2021] [Accepted: 09/03/2021] [Indexed: 11/22/2022]
Abstract
Glioblastoma are heterogeneous tumors composed of highly invasive and highly proliferative clones. Heterogeneity in invasiveness could emerge from discrete biophysical properties linked to specific molecular expression. We identified clones of patient-derived glioma propagating cells that were either highly proliferative or highly invasive and compared their cellular architecture, migratory, and biophysical properties. We discovered that invasiveness was linked to cellular fitness. The most invasive cells were stiffer, developed higher mechanical forces on the substrate, and moved stochastically. The mechano-chemical-induced expression of the formin FMN1 conferred invasive strength that was confirmed in patient samples. Moreover, FMN1 expression was also linked to motility in other cancer and normal cell lines, and its ectopic expression increased fitness parameters. Mechanistically, FMN1 acts from the microtubule lattice and promotes a robust mechanical cohesion, leading to highly invasive motility.
Collapse
|
18
|
Leite ML, Soares DG, Anovazzi G, Mendes Soares IP, Hebling J, de Souza Costa CA. Development of fibronectin-loaded nanofiber scaffolds for guided pulp tissue regeneration. J Biomed Mater Res B Appl Biomater 2020; 109:1244-1258. [PMID: 33381909 DOI: 10.1002/jbm.b.34785] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/28/2020] [Accepted: 12/08/2020] [Indexed: 01/26/2023]
Abstract
Fibronectin (FN)-loaded nanofiber scaffolds were developed and assessed concerning their bioactive potential on human apical papilla cells (hAPCs). First, random (NR) and aligned (NA) nanofiber scaffolds of polycaprolactone (PCL) were obtained by electrospinning technique and their biological properties were evaluated. The best formulations of NR and NA were loaded with 0, 5, or 10 μg/ml of FN and their bioactivity was assessed. Finally, FN-loaded NR and NA tubular scaffolds were prepared and their chemotactic potential was analyzed using an in vitro model to mimic the pulp regeneration of teeth with incomplete root formation. All scaffolds tested were cytocompatible. However, NR and NA based on 10% PCL promoted the highest hAPCs proliferation, adhesion and spreading. Polygonal and elongated cells were observed on NR and NA, respectively. The higher the concentration of FN added to the scaffolds, greater cell migration, viability, proliferation, adhesion and spreading, as well as collagen synthesis and gene expression (ITGA5, ITGAV, COL1A1, COL3A1). In addition, tubular scaffolds with NA loaded with FN (10 μg/ml) showed the highest chemotactic potential on hAPCs. It was concluded that FN-loaded NA scaffolds may be an interesting biomaterial to promote hAPCs-mediated pulp regeneration of endodontically compromised teeth with incomplete root formation.
Collapse
Affiliation(s)
- Maria Luísa Leite
- Department of Dental Materials and Prosthodontics, Araraquara School of Dentistry, Universidade Estadual Paulista, Araraquara, Brazil
| | - Diana Gabriela Soares
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, Sao Paulo University, Bauru, Brazil
| | - Giovana Anovazzi
- Departament of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, São Paulo State University, Araraquara, Brazil
| | - Igor Paulino Mendes Soares
- Department of Dental Materials and Prosthodontics, Araraquara School of Dentistry, Universidade Estadual Paulista, Araraquara, Brazil
| | - Josimeri Hebling
- Departament of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, São Paulo State University, Araraquara, Brazil
| | - Carlos Alberto de Souza Costa
- Department of Physiology and Pathology, Araraquara School of Dentistry, São Paulo State University, Araraquara, Brazil
| |
Collapse
|
19
|
Thanuthanakhun N, Kino-Oka M, Borwornpinyo S, Ito Y, Kim MH. The impact of culture dimensionality on behavioral epigenetic memory contributing to pluripotent state of iPS cells. J Cell Physiol 2020; 236:4985-4996. [PMID: 33305410 DOI: 10.1002/jcp.30211] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022]
Abstract
Three-dimensional (3D) culture platforms have been explored to establish physiologically relevant cell culture environment and permit expansion scalability; however, little is known about the mechanisms underlying the regulation of pluripotency of human induced pluripotent stem cells (hiPSCs). This study elucidated epigenetic modifications contributing to pluripotency of hiPSCs in response to 3D culture. Unlike two-dimensional (2D) monolayer cultures, 3D cultured cells aggregated with each other to form ball-like aggregates. 2D cultured cells expressed elevated levels of Rac1 and RhoA; however, Rac1 level was significantly lower while RhoA level was persisted in 3D aggregates. Compared with 2D monolayers, the 3D aggregates also exhibited significantly lower myosin phosphorylation. Histone methylation analysis revealed remarkable H3K4me3 upregulation and H3K27me3 maintenance throughout the duration of 3D culture; in addition, we observed the existence of naïve pluripotency signatures in cells grown in 3D culture. These results demonstrated that hiPSCs adapted to 3D culture through alteration of the Rho-Rho kinase-phospho-myosin pathway, influencing the epigenetic modifications and transcriptional expression of pluripotency-associated factors. These results may help design culture environments for stable and high-quality hiPSCs.
Collapse
Affiliation(s)
- Naruchit Thanuthanakhun
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Masahiro Kino-Oka
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| | - Suparerk Borwornpinyo
- Department of Biotechnology, Faculty of Science, Mahidol University, Ratchathewi, Bangkok, Thailand
| | - Yuzuru Ito
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Mee-Hae Kim
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan
| |
Collapse
|
20
|
Bodor DL, Pönisch W, Endres RG, Paluch EK. Of Cell Shapes and Motion: The Physical Basis of Animal Cell Migration. Dev Cell 2020; 52:550-562. [PMID: 32155438 DOI: 10.1016/j.devcel.2020.02.013] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/10/2020] [Accepted: 02/14/2020] [Indexed: 01/31/2023]
Abstract
Motile cells have developed a variety of migration modes relying on diverse traction-force-generation mechanisms. Before the behavior of intracellular components could be easily imaged, cell movements were mostly classified by different types of cellular shape dynamics. Indeed, even though some types of cells move without any significant change in shape, most cell propulsion mechanisms rely on global or local deformations of the cell surface. In this review, focusing mostly on metazoan cells, we discuss how different types of local and global shape changes underlie distinct migration modes. We then discuss mechanical differences between force-generation mechanisms and finish by speculating on how they may have evolved.
Collapse
Affiliation(s)
- Dani L Bodor
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Oncode Institute, Hubrecht Institute-KNAW, Utrecht, the Netherlands
| | - Wolfram Pönisch
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Robert G Endres
- Department of Life Sciences and Centre for Integrative Systems Biology and Bioinformatics, Imperial College, London SW7 2AZ, UK
| | - Ewa K Paluch
- MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK; Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK.
| |
Collapse
|
21
|
Maxian O, Mogilner A, Strychalski W. Computational estimates of mechanical constraints on cell migration through the extracellular matrix. PLoS Comput Biol 2020; 16:e1008160. [PMID: 32853248 PMCID: PMC7480866 DOI: 10.1371/journal.pcbi.1008160] [Citation(s) in RCA: 4] [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: 01/30/2020] [Revised: 09/09/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022] Open
Abstract
Cell migration through a three-dimensional (3D) extracellular matrix (ECM) underlies important physiological phenomena and is based on a variety of mechanical strategies depending on the cell type and the properties of the ECM. By using computer simulations of the cell’s mid-plane, we investigate two such migration mechanisms—‘push-pull’ (forming a finger-like protrusion, adhering to an ECM node, and pulling the cell body forward) and ‘rear-squeezing’ (pushing the cell body through the ECM by contracting the cell cortex and ECM at the cell rear). We present a computational model that accounts for both elastic deformation and forces of the ECM, an active cell cortex and nucleus, and for hydrodynamic forces and flow of the extracellular fluid, cytoplasm, and nucleoplasm. We find that relations between three mechanical parameters—the cortex’s contractile force, nuclear elasticity, and ECM rigidity—determine the effectiveness of cell migration through the dense ECM. The cell can migrate persistently even if its cortical contraction cannot deform a near-rigid ECM, but then the contraction of the cortex has to be able to sufficiently deform the nucleus. The cell can also migrate even if it fails to deform a stiff nucleus, but then it has to be able to sufficiently deform the ECM. Simulation results show that nuclear stiffness limits the cell migration more than the ECM rigidity. Simulations show the rear-squeezing mechanism of motility results in more robust migration with larger cell displacements than those with the push-pull mechanism over a range of parameter values. Additionally, results show that the rear-squeezing mechanism is aided by hydrodynamics through a pressure gradient. Computational simulations of two different mechanisms of 3D cell migration in an extracellular matrix are presented. One mechanism represents a mesenchymal mode, characterized by finger-like actin protrusions, while the second mode is more amoeboid in that rear contraction of the cortex propels the cell forward. In both mechanisms, the cell generates a thin actin protrusion on the cortex that attaches to an ECM node. The cell is then either pulled (mesenchymal) or pushed (amoeboid) forward. Results show both mechanisms result in successful migration over a range of simulated parameter values as long as the contractile tension of the cortex exceeds either the nuclear stiffness or ECM stiffness, but not necessarily both. However, the distance traveled by the amoeboid migration mode is more robust to changes in parameter values, and is larger than in simulations of the mesenchymal mode. Additionally, cells experience a favorable fluid pressure gradient when migrating in the amoeboid mode, and an adverse fluid pressure gradient in the mesenchymal mode.
Collapse
Affiliation(s)
- Ondrej Maxian
- Courant Institute of Mathematical Sciences, New York University, New York, New York, United States of America
| | - Alex Mogilner
- Courant Institute of Mathematical Sciences, New York University, New York, New York, United States of America
- Department of Biology, New York University, New York, New York, United States of America
| | - Wanda Strychalski
- Department of Mathematics, Applied Mathematics and Statistics, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| |
Collapse
|
22
|
Padhi A, Singh K, Franco-Barraza J, Marston DJ, Cukierman E, Hahn KM, Kapania RK, Nain AS. Force-exerting perpendicular lateral protrusions in fibroblastic cell contraction. Commun Biol 2020; 3:390. [PMID: 32694539 PMCID: PMC7374753 DOI: 10.1038/s42003-020-01117-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Accepted: 06/29/2020] [Indexed: 02/06/2023] Open
Abstract
Aligned extracellular matrix fibers enable fibroblasts to undergo myofibroblastic activation and achieve elongated shapes. Activated fibroblasts are able to contract, perpetuating the alignment of these fibers. This poorly understood feedback process is critical in chronic fibrosis conditions, including cancer. Here, using fiber networks that serve as force sensors, we identify "3D perpendicular lateral protrusions" (3D-PLPs) that evolve from lateral cell extensions named twines. Twines originate from stratification of cyclic-actin waves traversing the cell and swing freely in 3D to engage neighboring fibers. Once engaged, a lamellum forms and extends multiple secondary twines, which fill in to form a sheet-like PLP, in a force-entailing process that transitions focal adhesions to activated (i.e., pathological) 3D-adhesions. The specific morphology of PLPs enables cells to increase contractility and force on parallel fibers. Controlling geometry of extracellular networks confirms that anisotropic fibrous environments support 3D-PLP formation and function, suggesting an explanation for cancer-associated desmoplastic expansion.
Collapse
Affiliation(s)
- Abinash Padhi
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Karanpreet Singh
- Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Janusz Franco-Barraza
- Cancer Biology Program, Marvin & Concetta Greenberg Pancreatic Cancer Institute, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Daniel J Marston
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Edna Cukierman
- Cancer Biology Program, Marvin & Concetta Greenberg Pancreatic Cancer Institute, Fox Chase Cancer Center, Philadelphia, PA, USA.
| | - Klaus M Hahn
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Rakesh K Kapania
- Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Amrinder S Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA, USA.
| |
Collapse
|
23
|
Beta C, Gov NS, Yochelis A. Why a Large-Scale Mode Can Be Essential for Understanding Intracellular Actin Waves. Cells 2020; 9:cells9061533. [PMID: 32585983 PMCID: PMC7349605 DOI: 10.3390/cells9061533] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/16/2020] [Accepted: 06/18/2020] [Indexed: 01/18/2023] Open
Abstract
During the last decade, intracellular actin waves have attracted much attention due to their essential role in various cellular functions, ranging from motility to cytokinesis. Experimental methods have advanced significantly and can capture the dynamics of actin waves over a large range of spatio-temporal scales. However, the corresponding coarse-grained theory mostly avoids the full complexity of this multi-scale phenomenon. In this perspective, we focus on a minimal continuum model of activator-inhibitor type and highlight the qualitative role of mass conservation, which is typically overlooked. Specifically, our interest is to connect between the mathematical mechanisms of pattern formation in the presence of a large-scale mode, due to mass conservation, and distinct behaviors of actin waves.
Collapse
Affiliation(s)
- Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany;
| | - Nir S. Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Arik Yochelis
- Department of Solar Energy and Environmental Physics, Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
- Department of Physics, Ben-Gurion University of the Negev, Be’er Sheva 8410501, Israel
- Correspondence:
| |
Collapse
|
24
|
Diverse roles of non-muscle myosin II contractility in 3D cell migration. Essays Biochem 2020; 63:497-508. [PMID: 31551323 DOI: 10.1042/ebc20190026] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/15/2019] [Accepted: 08/27/2019] [Indexed: 01/13/2023]
Abstract
All is flux, nothing stays still. Heraclitus of Ephesus' characterization of the universe holds true for cells within animals and for proteins within cells. In this review, we examine the dynamics of actin and non-muscle myosin II within cells, and how their dynamics power the movement of cells within tissues. The 3D environment that migrating cells encounter along their path also changes over time, and cells can adopt various mechanisms of motility, depending on the topography, mechanics and chemical composition of their surroundings. We describe the differential spatio-temporal regulation of actin and myosin II-mediated contractility in mesenchymal, lobopodial, amoeboid, and swimming modes of cell migration. After briefly reviewing the biochemistry of myosin II, we discuss the role actomyosin contractility plays in the switch between modes of 3D migration that cells use to adapt to changing environments.
Collapse
|
25
|
Topographic cues reveal filopodia-mediated cell locomotion in 3D microenvironment. Biointerphases 2020; 15:031001. [PMID: 32366106 DOI: 10.1116/1.5141051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In cell-material interactions, the formation and functioning of filopodia have been demonstrated to be very sensitive to topographic cues. However, substrate-exploring functions of filopodia in a 3D microenvironment remain elusive. In this study, the silk fibroin film with a micropillar structure was prepared to reveal a filopodial-mediated cell response to 3D topographic cues. The micropillars provided a confined space for cell spreading by a simplified 3D structure, allowing initial cells to settle on the bottom of substrates rather than on the top of micropillars. Shortly after cell adhesion, the authors describe how cells transform from a filopodia-rich spherical cell state to a lamellipodia-dominated state that enables cell to climb along micropillars and spread on the top of the micropillars. The authors found that filopodia not only served as sensors for pathfinding but also provided nucleation scaffolds for the formation and orientation of minilamellipodia on the micropillar substrate. On the route of long filopodial extension following micropillars, all three functional filopodial adhesions have the ability to form veil-like minilamellipodium, simply by tethering the filopodium to the micropillars. Stable filopodia contacts consistently stimulated the local protrusion of a lamellipodium, which ultimately steered cell migration. Their results suggest the filopodia-mediated cell locomotion in the 3D microenvironment using a filopodia-to-minilamellipodium transformation mechanism.
Collapse
|
26
|
Mogilner A, Barnhart EL, Keren K. Experiment, theory, and the keratocyte: An ode to a simple model for cell motility. Semin Cell Dev Biol 2020; 100:143-151. [DOI: 10.1016/j.semcdb.2019.10.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 01/20/2023]
|
27
|
Messi Z, Bornert A, Raynaud F, Verkhovsky AB. Traction Forces Control Cell-Edge Dynamics and Mediate Distance Sensitivity during Cell Polarization. Curr Biol 2020; 30:1762-1769.e5. [PMID: 32220324 DOI: 10.1016/j.cub.2020.02.078] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 12/20/2019] [Accepted: 02/25/2020] [Indexed: 02/08/2023]
Abstract
Traction forces are generated by cellular actin-myosin system and transmitted to the environment through adhesions. They are believed to drive cell motion, shape changes, and extracellular matrix remodeling [1-3]. However, most of the traction force analysis has been performed on stationary cells, investigating forces at the level of individual focal adhesions or linking them to static cell parameters, such as area and edge curvature [4-10]. It is not well understood how traction forces are related to shape changes and motion, e.g., forces were reported to either increase or drop prior to cell retraction [11-15]. Here, we analyze the dynamics of traction forces during the protrusion-retraction cycle of polarizing fish epidermal keratocytes and find that forces fluctuate together with the cycle, increasing during protrusion and reaching maximum at the beginning of retraction. We relate force dynamics to the recently discovered phenomenological rule [16] that governs cell-edge behavior during keratocyte polarization: both traction forces and probability of switch from protrusion to retraction increase with the distance from the cell center. Diminishing forces with cell contractility inhibitor leads to decreased edge fluctuations and abnormal polarization, although externally applied force can induce protrusion-retraction switch. These results suggest that forces mediate distance sensitivity of the edge dynamics and organize cell-edge behavior, leading to spontaneous polarization. Actin flow rate did not exhibit the same distance dependence as traction stress, arguing against its role in organizing edge dynamics. Finally, using a simple model of actin-myosin network, we show that force-distance relationship might be an emergent feature of such networks.
Collapse
Affiliation(s)
- Zeno Messi
- Laboratory of Physics of Living Matter, EPFL, Route de la Sorge, Lausanne 1015, Switzerland.
| | - Alicia Bornert
- Laboratory of Physics of Living Matter, EPFL, Route de la Sorge, Lausanne 1015, Switzerland
| | - Franck Raynaud
- Scientific and Parallel Computing Group, Computer Science Department, University of Geneva, Route de Drize, Carouge 1227, Switzerland
| | - Alexander B Verkhovsky
- Laboratory of Physics of Living Matter, EPFL, Route de la Sorge, Lausanne 1015, Switzerland.
| |
Collapse
|
28
|
Abstract
Cytokinesis-the division of a cell into two daughter cells-is a key step in cell growth and proliferation. It typically occurs in synchrony with the cell cycle to ensure that a complete copy of the genetic information is passed on to the next generation of daughter cells. In animal cells, cytokinesis commonly relies on an actomyosin contractile ring that drives equatorial furrowing and separation into the two daughter cells. However, also contractile ring-independent forms of cell division are known that depend on substrate-mediated traction forces. Here, we report evidence of an as yet unknown type of contractile ring-independent cytokinesis that we termed wave-mediated cytofission. It is driven by self-organized cortical actin waves that travel across the ventral membrane of oversized, multinucleated Dictyostelium discoideum cells. Upon collision with the cell border, waves may initiate the formation of protrusions that elongate and eventually pinch off to form separate daughter cells. They are composed of a stable elongated wave segment that is enclosed by a cell membrane and moves in a highly persistent fashion. We rationalize our observations based on a noisy excitable reaction-diffusion model in combination with a dynamic phase field to account for the cell shape and demonstrate that daughter cells emerging from wave-mediated cytofission exhibit a well-controlled size.
Collapse
|
29
|
Mai MH, Camley BA. Hydrodynamic effects on the motility of crawling eukaryotic cells. SOFT MATTER 2020; 16:1349-1358. [PMID: 31934705 DOI: 10.1039/c9sm01797f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Eukaryotic cell motility is crucial during development, wound healing, the immune response, and cancer metastasis. Some eukaryotic cells can swim, but cells more commonly adhere to and crawl along the extracellular matrix. We study the relationship between hydrodynamics and adhesion that describe whether a cell is swimming, crawling, or combining these motions. Our simple model of a cell, based on the three-sphere swimmer, is capable of both swimming and crawling. As cell-matrix adhesion strength increases, the influence of hydrodynamics on migration diminishes. Cells with significant adhesion can crawl with speeds much larger than their nonadherent, swimming counterparts. We predict that, while most eukaryotic cells are in the strong-adhesion limit, increasing environment viscosity or decreasing cell-matrix adhesion could lead to significant hydrodynamic effects even in crawling cells. Signatures of hydrodynamic effects include a dependence of cell speed on the presence of a nearby substrate or interactions between noncontacting cells. These signatures will be suppressed at large adhesion strengths, but even strongly adherent cells will generate relevant fluid flows that will advect nearby passive particles and swimmers.
Collapse
Affiliation(s)
- Melissa H Mai
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, USA
| | | |
Collapse
|
30
|
Microtubule-Actomyosin Mechanical Cooperation during Contact Guidance Sensing. Cell Rep 2019; 25:328-338.e5. [PMID: 30304674 PMCID: PMC6226003 DOI: 10.1016/j.celrep.2018.09.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/20/2018] [Accepted: 09/07/2018] [Indexed: 01/14/2023] Open
Abstract
Cancer cell migration through and away from tumors is driven in part by migration along aligned extracellular matrix, a process known as contact guidance (CG). To concurrently study the influence of architectural and mechanical regulators of CG sensing, we developed a set of CG platforms. Using flat and nanotextured substrates with variable architectures and stiffness, we show that CG sensing is regulated by substrate stiffness and define a mechanical role for microtubules and actomyosin-microtubule interactions during CG sensing. Furthermore, we show that Arp2/3-dependent lamellipodia dynamics can compete with aligned protrusions to diminish the CG response and define Arp2/3- and Formins-dependent actin architectures that regulate microtu-bule-dependent protrusions, which promote the CG response. Thus, our work represents a comprehen-sive examination of the physical mechanisms influ-encing CG sensing. Aligned extracellular matrix architectures in tumors direct migration of invasive cancer cells. Tabdanov et al. show that the mechanical properties of aligned extracellular matrix environments influence invasive cell behavior and define a mechanical role for microtubules and actomyosin-microtubule interactions during sensing of contact guidance cues that arise from aligned extracellular matrix.
Collapse
|
31
|
Morrow CM, Mukherjee A, Traore MA, Leaman EJ, Kim A, Smith EM, Nain AS, Behkam B. Integrating nanofibers with biochemical gradients to investigate physiologically-relevant fibroblast chemotaxis. LAB ON A CHIP 2019; 19:3641-3651. [PMID: 31560021 DOI: 10.1039/c9lc00602h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Persistent cell migration can occur due to anisotropy in the extracellular matrix (ECM), the gradient of a chemo-effector, or a combination of both. Through a variety of in vitro platforms, the contributions of either stimulus have been extensively studied, while the combined effect of both cues remains poorly described. Here, we report an integrative microfluidic chemotaxis assay device that enables the study of single cell chemotaxis on ECM-mimicking, aligned, and suspended nanofibers. Using this assay, we evaluated the effect of fiber spacing on the morphology and chemotaxis response of embryonic murine NIH/3T3 fibroblasts in the presence of temporally invariant, linear gradients of platelet-derived growth factor-BB (PDGF-BB). We found that the strength of PDGF-mediated chemotaxis response depends on not only the gradient slope but also the cell morphology. Low aspect ratio (3.4 ± 0.2) cells on flat substrata exhibited a chemotaxis response only at a PDGF-BB gradient of 0-10 ng mL-1. However, high aspect ratio (19.1 ± 0.7) spindle-shaped cells attached to individual fibers exhibited maximal chemotaxis response at a ten-fold shallower gradient of 0-1 ng mL-1, which was robustly maintained up to 0-10 ng mL-1. Quadrilateral-shaped cells of intermediate aspect ratio (13.6 ± 0.8) attached to two fibers exhibited a weaker response compared to the spindle-shaped cells, but still stronger compared to cells attached to 2D featureless substrata. Through pharmacological inhibition, we show that the mesenchymal chemotaxis pathway is conserved in cells on fibers. Altogether, our findings show that chemotaxis on ECM-mimicking fibers is modulated by fiber spacing-driven cell shape and can be significantly different from the behavior observed on flat 2D substrata. We envisage that this microfluidic platform will have wide applicability in understanding the combined role of ECM architecture and chemotaxis in physiological and pathological processes.
Collapse
Affiliation(s)
- Carmen M Morrow
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Apratim Mukherjee
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Mahama A Traore
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA. and School of Biomedical Engineering & Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Eric J Leaman
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
| | - AhRam Kim
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Evan M Smith
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Amrinder S Nain
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA. and School of Biomedical Engineering & Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Bahareh Behkam
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA. and School of Biomedical Engineering & Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| |
Collapse
|
32
|
From macroscopic mechanics to cell-effective stiffness within highly aligned macroporous collagen scaffolds. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 103:109760. [DOI: 10.1016/j.msec.2019.109760] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 12/24/2022]
|
33
|
Yamada KM, Collins JW, Cruz Walma DA, Doyle AD, Morales SG, Lu J, Matsumoto K, Nazari SS, Sekiguchi R, Shinsato Y, Wang S. Extracellular matrix dynamics in cell migration, invasion and tissue morphogenesis. Int J Exp Pathol 2019; 100:144-152. [PMID: 31179622 DOI: 10.1111/iep.12329] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 05/10/2019] [Accepted: 05/12/2019] [Indexed: 12/14/2022] Open
Abstract
This review describes how direct visualization of the dynamic interactions of cells with different extracellular matrix microenvironments can provide novel insights into complex biological processes. Recent studies have moved characterization of cell migration and invasion from classical 2D culture systems into 1D and 3D model systems, revealing multiple differences in mechanisms of cell adhesion, migration and signalling-even though cells in 3D can still display prominent focal adhesions. Myosin II restrains cell migration speed in 2D culture but is often essential for effective 3D migration. 3D cell migration modes can switch between lamellipodial, lobopodial and/or amoeboid depending on the local matrix environment. For example, "nuclear piston" migration can be switched off by local proteolysis, and proteolytic invadopodia can be induced by a high density of fibrillar matrix. Particularly, complex remodelling of both extracellular matrix and tissues occurs during morphogenesis. Extracellular matrix supports self-assembly of embryonic tissues, but it must also be locally actively remodelled. For example, surprisingly focal remodelling of the basement membrane occurs during branching morphogenesis-numerous tiny perforations generated by proteolysis and actomyosin contractility produce a microscopically porous, flexible basement membrane meshwork for tissue expansion. Cells extend highly active blebs or protrusions towards the surrounding mesenchyme through these perforations. Concurrently, the entire basement membrane undergoes translocation in a direction opposite to bud expansion. Underlying this slowly moving 2D basement membrane translocation are highly dynamic individual cell movements. We conclude this review by describing a variety of exciting research opportunities for discovering novel insights into cell-matrix interactions.
Collapse
Affiliation(s)
- Kenneth M Yamada
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Joshua W Collins
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - David A Cruz Walma
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Andrew D Doyle
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Shaimar Gonzalez Morales
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Jiaoyang Lu
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Kazue Matsumoto
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Shayan S Nazari
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Rei Sekiguchi
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Yoshinari Shinsato
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| | - Shaohe Wang
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
34
|
Chen T, Callan-Jones A, Fedorov E, Ravasio A, Brugués A, Ong HT, Toyama Y, Low BC, Trepat X, Shemesh T, Voituriez R, Ladoux B. Large-scale curvature sensing by directional actin flow drives cellular migration mode switching. NATURE PHYSICS 2019; 15:393-402. [PMID: 30984281 PMCID: PMC6456019 DOI: 10.1038/s41567-018-0383-6] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 11/14/2018] [Indexed: 05/21/2023]
Abstract
Cell migration over heterogeneous substrates during wound healing or morphogenetic processes leads to shape changes driven by different organizations of the actin cytoskeleton and by functional changes including lamellipodial protrusions and contractile actin cables. Cells distinguish between cell-sized positive and negative curvatures in their physical environment by forming protrusions at positive ones and actin cables at negative ones; however, the cellular mechanisms remain unclear. Here, we report that concave edges promote polarized actin structures with actin flow directed towards the cell edge, in contrast to well-documented retrograde flow at convex edges. Anterograde flow and contractility induce a tension anisotropy gradient. A polarized actin network is formed, accompanied by a local polymerization-depolymerization gradient, together with leading-edge contractile actin cables in the front. These cables extend onto non-adherent regions while still maintaining contact with the substrate through focal adhesions. The contraction and dynamic reorganization of this actin structure allows forward movements enabling cell migration over non-adherent regions on the substrate. These versatile functional structures may help cells sense and navigate their environment by adapting to external geometric and mechanical cues.
Collapse
Affiliation(s)
- Tianchi Chen
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Andrew Callan-Jones
- Laboratoire Matière et Systèmes Complexes, UMR 7057, CNRS and Université Paris Diderot, Paris, France
| | | | - Andrea Ravasio
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Agustí Brugués
- Institute for Bioengineering of Catalonia, Barcelona, Spain
| | - Hui Ting Ong
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Yusuke Toyama
- Mechanobiology Institute, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore
- Temasek Life Sciences Laboratory, Singapore
| | - Boon Chuan Low
- Mechanobiology Institute, National University of Singapore, Singapore
- Department of Biological Sciences, National University of Singapore
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), and Universitat de Barcelona, Barcelona, Spain
| | - Tom Shemesh
- Technion – Israel Institute of Technology, Israel
| | - Raphaël Voituriez
- Laboratoire Jean Perrin and Laboratoire de Physique Theorique de la Matiere Condensee, CNRS/Sorbonne Université, Paris, France
- Corresponding authors: Benoît Ladoux; ; Raphaël Voituriez;
| | - Benoît Ladoux
- Mechanobiology Institute, National University of Singapore, Singapore
- Institut Jacques Monod (IJM), CNRS UMR 7592 & Université Paris Diderot, Paris, France
- Corresponding authors: Benoît Ladoux; ; Raphaël Voituriez;
| |
Collapse
|
35
|
CNT Incorporated Polyacrilonitrile/Polypyrrole Nanofibers as Keratinocytes Scaffold. JOURNAL OF BIOMIMETICS BIOMATERIALS AND BIOMEDICAL ENGINEERING 2019. [DOI: 10.4028/www.scientific.net/jbbbe.41.69] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polypyrrole (PPy) is an attractive scaffold material for tissue engineering with its non-toxic and electrically conductive properties. There has not been enough information about PPy usage in skin tissue engineering. The aim of this study is to investigate biocompatibility of polyacrilonitrile (PAN)/PPy nanofibrous scaffold for human keratinocytes. PAN/PPy bicomponent nanofibers were prepared by electrospinning, in various PPy concentrations and with carbon nanotube (CNT) incorporation. The average diameter of electrospun nanofibers decreased with increasing PPy concentration. Further, agglomerated CNTs caused beads and disordered parts on the surface of nanofibers. Biocompatibility of these PAN/PPy and PAN/PPy/CNT scaffolds were analyzed in vitro. Both scaffolds provided adhesion and proliferation of keratinocytes. Nanofiber diameter did not significantly influence the morphology of cells. However, with increasing number of cells, cells stayed among nanofibers and this affected their shape and size. In this study, we demonstrated that PAN/PPy and PAN/PPy/CNT scaffolds enabled the growth of keratinocytes, showing their biocompatibility.
Collapse
|
36
|
Eftekharjoo M, Palmer D, McCoy B, Maruthamuthu V. Fibrillar force generation by fibroblasts depends on formin. Biochem Biophys Res Commun 2019; 510:72-77. [PMID: 30660364 DOI: 10.1016/j.bbrc.2019.01.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 01/07/2019] [Indexed: 01/06/2023]
Abstract
Fibroblasts in the extra-cellular matrix (ECM) often adopt a predominantly one-dimensional fibrillar geometry by virtue of their adhesion to the fibrils in the ECM. How much forces such fibrillar fibroblasts exert and how they respond to the extended stiffness of their micro-environment comprising of other ECM components and cells are not clear. We use fibroblasts adherent on fibronectin lines micropatterned onto soft polyacrylamide gels as an in vitro experimental model that maintains fibrillar cell morphology while still letting the cell mechanically interact with a continuous micro-environment of specified stiffness. We find that the exerted traction, quantified as the strain energy or the maximum exerted traction stress, is not a function of cell length. Both the strain energy and the maximum traction stress exerted by fibrillar cells are similar for low (13 kPa) or high (45 kPa) micro-environmental stiffness. Furthermore, we find that fibrillar fibroblasts exhibit prominent linear actin structures. Accordingly, inhibition of the formin family of nucleators strongly decreases the exerted traction forces. Interestingly, fibrillar cell migration is, however, not affected under formin inhibition. Our results suggest that fibrillar cell migration in such soft microenvironments is not dependent on high cellular force exertion in the absence of other topological constraints.
Collapse
Affiliation(s)
- Mohamad Eftekharjoo
- Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, VA, 23529, USA
| | - Dakota Palmer
- Department of Biological Sciences and Old Dominion University, Norfolk, VA, 23529, USA
| | - Breanna McCoy
- Department of Engineering Technology, Old Dominion University, Norfolk, VA, 23529, USA
| | - Venkat Maruthamuthu
- Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, VA, 23529, USA.
| |
Collapse
|
37
|
Garcia-Arcos JM, Chabrier R, Deygas M, Nader G, Barbier L, Sáez PJ, Mathur A, Vargas P, Piel M. Reconstitution of cell migration at a glance. J Cell Sci 2019; 132:132/4/jcs225565. [PMID: 30745333 DOI: 10.1242/jcs.225565] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Single cells migrate in a myriad of physiological contexts, such as tissue patrolling by immune cells, and during neurogenesis and tissue remodeling, as well as in metastasis, the spread of cancer cells. To understand the basic principles of single-cell migration, a reductionist approach can be taken. This aims to control and deconstruct the complexity of different cellular microenvironments into simpler elementary constrains that can be recombined together. This approach is the cell microenvironment equivalent of in vitro reconstituted systems that combine elementary molecular players to understand cellular functions. In this Cell Science at a Glance article and accompanying poster, we present selected experimental setups that mimic different events that cells undergo during migration in vivo These include polydimethylsiloxane (PDMS) devices to deform whole cells or organelles, micro patterning, nano-fabricated structures like grooves, and compartmentalized collagen chambers with chemical gradients. We also outline the main contribution of each technique to the understanding of different aspects of single-cell migration.
Collapse
Affiliation(s)
- Juan Manuel Garcia-Arcos
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Renaud Chabrier
- Institut Curie, PSL Research University, CNRS UMR3348, F-91405 Orsay, France
| | - Mathieu Deygas
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Guilherme Nader
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Lucie Barbier
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Pablo José Sáez
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Aastha Mathur
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Pablo Vargas
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France.,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| | - Matthieu Piel
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005 Paris, France .,Institut Pierre-Gilles de Gennes, PSL Research University, F-75005 Paris, France
| |
Collapse
|
38
|
Wang WY, Pearson AT, Kutys ML, Choi CK, Wozniak MA, Baker BM, Chen CS. Extracellular matrix alignment dictates the organization of focal adhesions and directs uniaxial cell migration. APL Bioeng 2018; 2:046107. [PMID: 31069329 PMCID: PMC6481732 DOI: 10.1063/1.5052239] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/20/2018] [Indexed: 01/16/2023] Open
Abstract
Physical features of the extracellular matrix (ECM) heavily influence cell migration strategies and efficiency. Migration in and on fibrous ECMs is of significant physiologic importance, but limitations in the ability to experimentally define the diameter, density, and alignment of native ECMs in vitro have hampered our understanding of how these properties affect this basic cell function. Here, we designed a high-throughput in vitro platform that models fibrous ECM as collections of lines of cell-adhesive fibronectin on a flat surface to eliminate effects of dimensionality and topography. Using a microcontact printing approach to orthogonally vary line alignment, density, and size, we determined each factor's individual influence on NIH3T3 fibroblast migration. High content imaging and statistical analyses revealed that ECM alignment is the most critical parameter in influencing cell morphology, polarization, and migratory behavior. Specifically, increasing ECM alignment led cells to adopt an elongated uniaxial morphology and migrate with enhanced speed and persistence. Intriguingly, migration speeds were tightly correlated with the organization of focal adhesions, where cells with the most aligned adhesions migrated fastest. Highly organized focal adhesions and associated actin stress fibers appeared to define the number and location of protrusive fronts, suggesting that ECM alignment influences active Rac1 localization. Utilizing a novel microcontact-printing approach that lacks confounding influences of substrate dimensionality, mechanics, or differences in the adhesive area, this work highlights the effect of ECM alignment on orchestrating the cytoskeletal machinery that governs directed uniaxial cell migration.
Collapse
Affiliation(s)
- William Y Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Alexander T Pearson
- Section of Hematology/Oncology, Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA
| | | | | | - Michele A Wozniak
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Brendon M Baker
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | |
Collapse
|
39
|
Xue J, Wu T, Xia Y. Perspective: Aligned arrays of electrospun nanofibers for directing cell migration. APL MATERIALS 2018; 6:120902. [PMID: 33335802 PMCID: PMC7743993 DOI: 10.1063/1.5058083] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cell migration plays an important role in a wide variety of biological processes, including embryogenesis, wound healing, inflammation, cancer metastasis, and tissue repair. Electrospun nanofibers have been extensively explored as scaffolds to manipulate cell migration owing to their unique characteristics in mimicking the hierarchical architecture of extracellular matrix. In particular, aligned arrays of electrospun nanofibers are capable of guiding and promoting the directional migration of cells. The physical parameters and properties of the aligned nanofibers, including their size, modulus, and surface chemistry, can all affect the migratory behaviors of cells, while the controlled release of growth factors and drugs from the nanofibers can also be utilized to influence cell migration. By manipulating cell migration, electrospun nanofibers have been applied to promote tissue repair and help eradicate tumors in vivo. In this perspective, we highlight recent developments in collecting electrospun nanofibers as aligned arrays and then illustrate how the aligned nanofibers can be utilized to manipulate cell migration.
Collapse
Affiliation(s)
- Jiajia Xue
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Tong Wu
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Younan Xia
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| |
Collapse
|
40
|
Bimodal sensing of guidance cues in mechanically distinct microenvironments. Nat Commun 2018; 9:4891. [PMID: 30459308 PMCID: PMC6244288 DOI: 10.1038/s41467-018-07290-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/16/2018] [Indexed: 01/03/2023] Open
Abstract
Contact guidance due to extracellular matrix architecture is a key regulator of carcinoma invasion and metastasis, yet our understanding of how cells sense guidance cues is limited. Here, using a platform with variable stiffness that facilitates uniaxial or biaxial matrix cues, or competing E-cadherin adhesions, we demonstrate distinct mechanoresponsive behavior. Through disruption of traction forces, we observe a profound phenotypic shift towards a mode of dendritic protrusion and identify bimodal processes that govern guidance sensing. In contractile cells, guidance sensing is strongly dependent on formins and FAK signaling and can be perturbed by disrupting microtubule dynamics, while low traction conditions initiate fluidic-like dendritic protrusions that are dependent on Arp2/3. Concomitant disruption of these bimodal mechanisms completely abrogates the contact guidance response. Thus, guidance sensing in carcinoma cells depends on both environment architecture and mechanical properties and targeting the bimodal responses may provide a rational strategy for disrupting metastatic behavior. Invasive cells respond to contact guidance cues during migration. Here, using micro- and nanopatterning with different ligands and varying stiffness, the authors find that cells can make cellular protrusions through both contractility-dependent and contractility-independent means.
Collapse
|
41
|
Chernonosova VS, Gostev AA, Gao Y, Chesalov YA, Shutov AV, Pokushalov EA, Karpenko AA, Laktionov PP. Mechanical Properties and Biological Behavior of 3D Matrices Produced by Electrospinning from Protein-Enriched Polyurethane. BIOMED RESEARCH INTERNATIONAL 2018; 2018:1380606. [PMID: 30046587 PMCID: PMC6038672 DOI: 10.1155/2018/1380606] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/16/2018] [Accepted: 05/29/2018] [Indexed: 02/07/2023]
Abstract
Properties of matrices manufactured by electrospinning from solutions of polyurethane Tecoflex EG-80A with gelatin in 1,1,1,3,3,3-hexafluoroisopropanol were studied. The concentration of gelatin added to the electrospinning solution was shown to influence the mechanical properties of matrices: the dependence of matrix tensile strength on protein concentration is described by a bell-shaped curve and an increase in gelatin concentration added to the elasticity of the samples. SEM, FTIR spectroscopy, and mechanical testing demonstrate that incubation of matrices in phosphate buffer changes the structure of the fibers and alters the polyurethane-gelatin interactions, increasing matrix durability. The ability of the matrices to maintain adhesion and proliferation of human endothelial cells was studied. The results suggest that matrices made of 3% polyurethane solution with 15% gelatin (wt/wt) and treated with glutaraldehyde are the optimal variant for cultivation of endothelial cells.
Collapse
Affiliation(s)
- Vera S. Chernonosova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation, Novosibirsk 630055, Russia
| | - Alexander A. Gostev
- Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation, Novosibirsk 630055, Russia
| | - Yun Gao
- Novosibirsk State University, Novosibirsk 630090, Russia
| | - Yuriy A. Chesalov
- Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Alexey V. Shutov
- Lavrentyev Institute of Hydrodynamics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Evgeniy A. Pokushalov
- Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation, Novosibirsk 630055, Russia
| | - Andrey A. Karpenko
- Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation, Novosibirsk 630055, Russia
| | - Pavel P. Laktionov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation, Novosibirsk 630055, Russia
| |
Collapse
|
42
|
A RAB35-p85/PI3K axis controls oscillatory apical protrusions required for efficient chemotactic migration. Nat Commun 2018; 9:1475. [PMID: 29662076 PMCID: PMC5902610 DOI: 10.1038/s41467-018-03571-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 02/15/2018] [Indexed: 11/17/2022] Open
Abstract
How cells move chemotactically remains a major unmet challenge in cell biology. Emerging evidence indicates that for interpreting noisy, shallow gradients of soluble cues a system must behave as an excitable process. Here, through an RNAi-based, high-content screening approach, we identify RAB35 as necessary for the formation of growth factors (GFs)-induced waves of circular dorsal ruffles (CDRs), apically restricted actin-rich migratory protrusions. RAB35 is sufficient to induce recurrent and polarized CDRs that travel as propagating waves, thus behaving as an excitable system that can be biased to control cell steering. Consistently, RAB35 is essential for promoting directed chemotactic migration and chemoinvasion of various cells in response to gradients of motogenic GFs. Molecularly, RAB35 does so by directly regulating the activity of p85/PI3K polarity axis. We propose that RAB35 is a molecular determinant for the control of an excitable, oscillatory system that acts as a steering wheel for GF-mediated chemotaxis and chemoinvasion. Circular dorsal ruffles (CDRs) are apical actin enriched structures involved in the interpretation of growth factor gradients during cell migration. Here, the authors find that a RAB35/PI3K axis is necessary and sufficient for the formation and stabilization of polarized CDRs and persistent directional migration.
Collapse
|
43
|
A cell surface display fluorescent biosensor for measuring MMP14 activity in real-time. Sci Rep 2018; 8:5916. [PMID: 29651043 PMCID: PMC5897415 DOI: 10.1038/s41598-018-24080-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/23/2018] [Indexed: 01/16/2023] Open
Abstract
Despite numerous recent advances in imaging technologies, one continuing challenge for cell biologists and microscopists is the visualization and measurement of endogenous proteins as they function within living cells. Achieving this goal will provide a tool that investigators can use to associate cellular outcomes with the behavior and activity of many well-studied target proteins. Here, we describe the development of a plasmid-based fluorescent biosensor engineered to measure the location and activity of matrix metalloprotease-14 (MMP14). The biosensor design uses fluorogen-activating protein technology coupled with a MMP14-selective protease sequence to generate a binary, “switch-on” fluorescence reporter capable of measuring MMP14 location, activity, and temporal dynamics. The MMP14-fluorogen activating protein biosensor approach is applicable to both short and long-term imaging modalities and contains an adaptable module that can be used to study many membrane-bound proteases. This MMP14 biosensor promises to serve as a tool for the advancement of a broad range of investigations targeting MMP14 activity during cell migration in health and disease.
Collapse
|
44
|
Chengappa P, Sao K, Jones TM, Petrie RJ. Intracellular Pressure: A Driver of Cell Morphology and Movement. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 337:185-211. [PMID: 29551161 DOI: 10.1016/bs.ircmb.2017.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intracellular pressure, generated by actomyosin contractility and the directional flow of water across the plasma membrane, can rapidly reprogram cell shape and behavior. Recent work demonstrates that cells can generate intracellular pressure with a range spanning at least two orders of magnitude; significantly, pressure is implicated as an important regulator of cell dynamics, such as cell division and migration. Changes to intracellular pressure can dictate the mechanisms by which single human cells move through three-dimensional environments. In this review, we chronicle the classic as well as recent evidence demonstrating how intracellular pressure is generated and maintained in metazoan cells. Furthermore, we highlight how this potentially ubiquitous physical characteristic is emerging as an important driver of cell morphology and behavior.
Collapse
Affiliation(s)
| | - Kimheak Sao
- Drexel University, Philadelphia, PA, United States
| | - Tia M Jones
- Drexel University, Philadelphia, PA, United States
| | | |
Collapse
|
45
|
Ren Y, Mlodzianoski MJ, Lee AC, Huang F, Suter DM. A low-cost microwell device for high-resolution imaging of neurite outgrowth in 3D. J Neural Eng 2018; 15:035001. [PMID: 29363623 DOI: 10.1088/1741-2552/aaaa32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Current neuronal cell culture is mostly performed on two-dimensional (2D) surfaces, which lack many of the important features of the native environment of neurons, including topographical cues, deformable extracellular matrix, and spatial isotropy or anisotropy in three dimensions. Although three-dimensional (3D) cell culture systems provide a more physiologically relevant environment than 2D systems, their popularity is greatly hampered by the lack of easy-to-make-and-use devices. We aim to develop a widely applicable 3D culture procedure to facilitate the transition of neuronal cultures from 2D to 3D. APPROACH We made a simple microwell device for 3D neuronal cell culture that is inexpensive, easy to assemble, and fully compatible with commonly used imaging techniques, including super-resolution microscopy. MAIN RESULTS We developed a novel gel mixture to support 3D neurite regeneration of Aplysia bag cell neurons, a system that has been extensively used for quantitative analysis of growth cone dynamics in 2D. We found that the morphology and growth pattern of bag cell growth cones in 3D culture closely resemble the ones of growth cones observed in vivo. We demonstrated the capability of our device for high-resolution imaging of cytoskeletal and signaling proteins as well as organelles. SIGNIFICANCE Neuronal cell culture has been a valuable tool for neuroscientists to study the behavior of neurons in a controlled environment. Compared to 2D, neurons cultured in 3D retain the majority of their native characteristics, while offering higher accessibility, control, and repeatability. We expect that our microwell device will facilitate a wider adoption of 3D neuronal cultures to study the mechanisms of neurite regeneration.
Collapse
Affiliation(s)
- Yuan Ren
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, United States of America
| | | | | | | | | |
Collapse
|
46
|
Fritz-Laylin LK, Riel-Mehan M, Chen BC, Lord SJ, Goddard TD, Ferrin TE, Nicholson-Dykstra SM, Higgs H, Johnson GT, Betzig E, Mullins RD. Actin-based protrusions of migrating neutrophils are intrinsically lamellar and facilitate direction changes. eLife 2017; 6. [PMID: 28948912 PMCID: PMC5614560 DOI: 10.7554/elife.26990] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 08/09/2017] [Indexed: 01/01/2023] Open
Abstract
Leukocytes and other amoeboid cells change shape as they move, forming highly dynamic, actin-filled pseudopods. Although we understand much about the architecture and dynamics of thin lamellipodia made by slow-moving cells on flat surfaces, conventional light microscopy lacks the spatial and temporal resolution required to track complex pseudopods of cells moving in three dimensions. We therefore employed lattice light sheet microscopy to perform three-dimensional, time-lapse imaging of neutrophil-like HL-60 cells crawling through collagen matrices. To analyze three-dimensional pseudopods we: (i) developed fluorescent probe combinations that distinguish cortical actin from dynamic, pseudopod-forming actin networks, and (ii) adapted molecular visualization tools from structural biology to render and analyze complex cell surfaces. Surprisingly, three-dimensional pseudopods turn out to be composed of thin (<0.75 µm), flat sheets that sometimes interleave to form rosettes. Their laminar nature is not templated by an external surface, but likely reflects a linear arrangement of regulatory molecules. Although we find that Arp2/3-dependent pseudopods are dispensable for three-dimensional locomotion, their elimination dramatically decreases the frequency of cell turning, and pseudopod dynamics increase when cells change direction, highlighting the important role pseudopods play in pathfinding.
Collapse
Affiliation(s)
- Lillian K Fritz-Laylin
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Megan Riel-Mehan
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States
| | - Bi-Chang Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Samuel J Lord
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Thomas D Goddard
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Thomas E Ferrin
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, United States
| | - Susan M Nicholson-Dykstra
- Department of Biochemistry and Cell Biology, Dartmouth Geisel School of Medicine, Hanover, United States
| | - Henry Higgs
- Department of Biochemistry and Cell Biology, Dartmouth Geisel School of Medicine, Hanover, United States
| | - Graham T Johnson
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, United States.,Animated Cell, Allen Institute for Cell Science, Seattle, United States
| | - Eric Betzig
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| |
Collapse
|
47
|
Pontes B, Monzo P, Gauthier NC. Membrane tension: A challenging but universal physical parameter in cell biology. Semin Cell Dev Biol 2017; 71:30-41. [PMID: 28851599 DOI: 10.1016/j.semcdb.2017.08.030] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/08/2017] [Accepted: 08/13/2017] [Indexed: 01/03/2023]
Abstract
The plasma membrane separates the interior of cells from the outside environment. The membrane tension, defined as the force per unit length acting on a cross-section of membrane, regulates many vital biological processes. In this review, we summarize the first historical findings and the latest advances, showing membrane tension as an important physical parameter in cell biology. We also discuss how this parameter must be better integrated and we propose experimental approaches for key unanswered questions.
Collapse
Affiliation(s)
- Bruno Pontes
- LPO-COPEA, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
| | - Pascale Monzo
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy
| | - Nils C Gauthier
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy.
| |
Collapse
|
48
|
Hani NM, Torkamani AE, Azarian MH, Mahmood KW, Ngalim SH. Characterisation of electrospun gelatine nanofibres encapsulated with Moringa oleifera bioactive extract. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2017; 97:3348-3358. [PMID: 27981649 DOI: 10.1002/jsfa.8185] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 11/23/2016] [Accepted: 12/12/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Drumstick (Moringa oleifera) leaves have been used as a folk herbal medicine across many cultures since ancient times. This is most probably due to presence of phytochemicals possessing antioxidant properties, which could retard oxidative stress, and their degenerative effect. The current study deals with nanoencapsulation of Moringa oleifera (MO) leaf ethanolic extract within fish sourced gelatine matrix using electrospinning technique. RESULTS The total phenolic and flavonoid content, radical scavenging (IC50 ) and metal reducing properties were 67.0 ± 2.5 mg GAE g-1 sample 32.0 ± 0.5 mg QE g-1 extract, 0.08 ± 0.01 mg mL-1 and 510 ± 10 µmol eq Fe(II) g-1 extract, respectively. Morphological and spectroscopic analysis of the fibre mats confirmed successful nanoencapsulation of MO extract within defect free nanofibres via electrospinning process. The percentage encapsulation efficiency (EE) was between 80% and 85%. Furthermore, thermal stability of encapsulated fibres, especially at 3% and 5% of core loading content, was significantly improved. Toxicological analysis revealed that the extract in its original and encapsulated form was safe for oral consumption. CONCLUSION Overall, the present study showed the potential of ambient temperature electrospinning process as a safe nanoencapsulation method, where MO extract retained its antioxidative capacities. © 2016 Society of Chemical Industry.
Collapse
Affiliation(s)
- Norziah M Hani
- Food Technology Department, School of Industrial Technology, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Amir E Torkamani
- Food Technology Department, School of Industrial Technology, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Mohammad H Azarian
- School of Chemical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Kamil Wa Mahmood
- School of Chemical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia
| | - Siti Hawa Ngalim
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, Penang, Malaysia
| |
Collapse
|
49
|
Schoppmeyer R, Zhao R, Cheng H, Hamed M, Liu C, Zhou X, Schwarz EC, Zhou Y, Knörck A, Schwär G, Ji S, Liu L, Long J, Helms V, Hoth M, Yu X, Qu B. Human profilin 1 is a negative regulator of CTL mediated cell-killing and migration. Eur J Immunol 2017; 47:1562-1572. [PMID: 28688208 DOI: 10.1002/eji.201747124] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 05/12/2017] [Accepted: 07/05/2017] [Indexed: 12/30/2022]
Abstract
The actin-binding protein profilin1 (PFN1) plays a central role in actin dynamics, which is essential for cytotoxic T lymphocyte (CTL) functions. The functional role of PFN1 in CTLs, however still remains elusive. Here, we identify PFN1 as the only member of the profilin family expressed in primary human CD8+ T cells. Using in vitro assays, we find that PFN1 is a negative regulator of CTL-mediated elimination of target cells. Furthermore, PFN1 is involved in activation-induced lytic granule (LG) release, CTL migration and modulation of actin structures at the immunological synapse (IS). During CTL migration, PFN1 modulates the velocity, protrusion formation patterns and protrusion sustainability. In contrast, PFN1 does not significantly affect migration persistence and the rates of protrusion emergence and retraction. Under in vitro conditions mimicking a tumor microenvironment, we show that PFN1 downregulation promotes CTL invasion into a 3D matrix, without affecting the viability of CTLs in a hydrogen peroxide-enriched microenvironment. Highlighting its potential relevance in cancer, we find that in pancreatic cancer patients, PFN1 expression is substantially decreased in peripheral CD8+ T cells. Taken together, we conclude that PFN1 is a negative regulator for CTL-mediated cytotoxicity and may have an impact on CTL functionality in a tumor-related context.
Collapse
Affiliation(s)
- Rouven Schoppmeyer
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Renping Zhao
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - He Cheng
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Mohamed Hamed
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany.,Institute for Biostatistics and Informatics in Medicine and Ageing Research, Rostock University Medical Centre, Rostock, Germany
| | - Chen Liu
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Xiao Zhou
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Eva C Schwarz
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Yan Zhou
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Arne Knörck
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Gertrud Schwär
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Shunrong Ji
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Liang Liu
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Jiang Long
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
| | - Markus Hoth
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| | - Xianjun Yu
- Department of Pancreatic and Hepatobiliary Surgery, Fudan University Shanghai Cancer Center, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Bin Qu
- Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, Homburg, Germany
| |
Collapse
|
50
|
Actin Waves: Origin of Cell Polarization and Migration? Trends Cell Biol 2017; 27:515-526. [DOI: 10.1016/j.tcb.2017.02.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/26/2017] [Accepted: 02/07/2017] [Indexed: 01/22/2023]
|