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Bakhshandeh B, Sorboni SG, Ranjbar N, Deyhimfar R, Abtahi MS, Izady M, Kazemi N, Noori A, Pennisi CP. Mechanotransduction in tissue engineering: Insights into the interaction of stem cells with biomechanical cues. Exp Cell Res 2023; 431:113766. [PMID: 37678504 DOI: 10.1016/j.yexcr.2023.113766] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/09/2023]
Abstract
Stem cells in their natural microenvironment are exposed to biochemical and biophysical cues emerging from the extracellular matrix (ECM) and neighboring cells. In particular, biomechanical forces modulate stem cell behavior, biological fate, and early developmental processes by sensing, interpreting, and responding through a series of biological processes known as mechanotransduction. Local structural changes in the ECM and mechanics are driven by reciprocal activation of the cell and the ECM itself, as the initial deposition of matrix proteins sequentially affects neighboring cells. Recent studies on stem cell mechanoregulation have provided insight into the importance of biomechanical signals on proper tissue regeneration and function and have shown that precise spatiotemporal control of these signals exists in stem cell niches. Against this background, the aim of this work is to review the current understanding of the molecular basis of mechanotransduction by analyzing how biomechanical forces are converted into biological responses via cellular signaling pathways. In addition, this work provides an overview of advanced strategies using stem cells and biomaterial scaffolds that enable precise spatial and temporal control of mechanical signals and offer great potential for the fields of tissue engineering and regenerative medicine will be presented.
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Affiliation(s)
- Behnaz Bakhshandeh
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran.
| | | | - Nika Ranjbar
- Department of Biotechnology, College of Science, University of Tehran, Tehran, Iran
| | - Roham Deyhimfar
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Maryam Sadat Abtahi
- Department of Biotechnology, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Mehrnaz Izady
- Department of Cellular and Molecular Biology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Navid Kazemi
- Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Atefeh Noori
- Department of Biotechnology, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran
| | - Cristian Pablo Pennisi
- Regenerative Medicine Group, Department of Health Science and Technology, Aalborg University, Denmark.
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2
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Brito C, Pereira JM, Mesquita FS, Cabanes D, Sousa S. Src-Dependent NM2A Tyrosine Phosphorylation Regulates Actomyosin Remodeling. Cells 2023; 12:1871. [PMID: 37508535 PMCID: PMC10377941 DOI: 10.3390/cells12141871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/07/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Non-muscle myosin 2A (NM2A) is a key cytoskeletal enzyme that, along with actin, assembles into actomyosin filaments inside cells. NM2A is fundamental for cell adhesion and motility, playing important functions in different stages of development and during the progression of viral and bacterial infections. Phosphorylation events regulate the activity and the cellular localization of NM2A. We previously identified the tyrosine phosphorylation of residue 158 (pTyr158) in the motor domain of the NM2A heavy chain. This phosphorylation can be promoted by Listeria monocytogenes infection of epithelial cells and is dependent on Src kinase; however, its molecular role is unknown. Here, we show that the status of pTyr158 defines cytoskeletal organization, affects the assembly/disassembly of focal adhesions, and interferes with cell migration. Cells overexpressing a non-phosphorylatable NM2A variant or expressing reduced levels of Src kinase display increased stress fibers and larger focal adhesions, suggesting an altered contraction status consistent with the increased NM2A activity that we also observed. We propose NM2A pTyr158 as a novel layer of regulation of actomyosin cytoskeleton organization.
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Affiliation(s)
- Cláudia Brito
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC, Instituto de Biologia Celular e Molecular, 4200-135 Porto, Portugal
- MCBiology PhD Program-Instituto de Ciências Biomédicas Abel Salazar-ICBAS, University of Porto, 4050-313 Porto, Portugal
| | - Joana M Pereira
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC, Instituto de Biologia Celular e Molecular, 4200-135 Porto, Portugal
- MCBiology PhD Program-Instituto de Ciências Biomédicas Abel Salazar-ICBAS, University of Porto, 4050-313 Porto, Portugal
| | - Francisco S Mesquita
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC, Instituto de Biologia Celular e Molecular, 4200-135 Porto, Portugal
| | - Didier Cabanes
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC, Instituto de Biologia Celular e Molecular, 4200-135 Porto, Portugal
| | - Sandra Sousa
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC, Instituto de Biologia Celular e Molecular, 4200-135 Porto, Portugal
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3
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Gao Q, Jia F, Li X, Kong Y, Tian Z, Bi L, Li L. Biophysical cues to improve the immunomodulatory capacity of mesenchymal stem cells: The progress and mechanisms. Biomed Pharmacother 2023; 162:114655. [PMID: 37031489 DOI: 10.1016/j.biopha.2023.114655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 04/11/2023] Open
Abstract
Mesenchymal stem cells (MSCs) can maintain immune homeostasis and many preclinical trials with MSCs have been carried out around the world. In vitro culture of MSCs has been found to result in the decline of immunomodulatory capacity, migration and proliferation. To address these problems, simulating the extracellular environment for preconditioning of MSCs is a promising and inexpensive method. Biophysical cues in the external environment that MSCs are exposed to have been shown to affect MSC migration, residency, differentiation, secretion, etc. We review the main ways in which MSCs exert their immunomodulatory ability, and summarize recent advances in mechanical preconditioning of MSCs to enhance immunomodulatory capacity and related mechanical signal sensing and transduction mechanisms.
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Affiliation(s)
- Qingyuan Gao
- Department of Hematology and Oncology, China-Japan Union Hospital of Jilin University, Changchun 130021, China
| | - Fangru Jia
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, Jilin Province, China
| | - Xiangpan Li
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, Jilin Province, China
| | - Yanan Kong
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, Jilin Province, China
| | - Zhenya Tian
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, Jilin Province, China
| | - Lintao Bi
- Department of Hematology and Oncology, China-Japan Union Hospital of Jilin University, Changchun 130021, China.
| | - Lisha Li
- The Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, Jilin Province, China.
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4
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Zhou Z, Zhang X, Zhou T, Huang F, Chen J. Quartz Crystal Microbalance Technology Coupled with Impedance for the Dynamic Monitoring of the Cardiomyocyte Beating Function and Drug Screening. BIOSENSORS 2023; 13:198. [PMID: 36831964 PMCID: PMC9953959 DOI: 10.3390/bios13020198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 06/18/2023]
Abstract
The main sensing techniques used to study myocardial pulsation are electrical impedance sensing (EIS) and by quartz crystal microbalance (QCM). While electrical impedance technology is the gold standard for the study of myocardial pulsation, the clinical application of drugs is being followed up in real time additionally, thus, QCM technology needs to be further developed as a very important class of quality sensor technology. Moreover, the application of EIS, in combination with the QCM, for monitoring myocardial pulsation, has been rarely reported. In this paper, a series of cell growth and adhesion conditions were optimized using rat primary cardiomyocytes, and QCM was used in combination with EIS to monitor the adhesion and the myocardial pulsation ability of the cells in real time. Furthermore, cardiomyocytes that adhered to the QCM and EIS were treated with isoprenaline (ISO), a positive inotropic drug, and verapamil (VRP), a negative inotropic drug. Next, the cell index (CI)-time (T) plots, beating amplitude (BA) and beating rate (BR) of the cardiomyocytes were calculated and changes in these parameters, before and after, dosing were evaluated. The results showed that the QCM technique results were not only consistent with the results obtained with EIS, but also that the QCM technique had a certain degree of sensitivity for the calculation of cardiomyocyte beating. Thus, our findings validate the reliability and validity of the QCM technique for measuring cardiomyocyte beating and drug testing. We hope that further studies would evaluate the application of the QCM technology for clinical use.
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Affiliation(s)
- Zhen Zhou
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
- Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China
| | - Xiaoyu Zhang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
- Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China
| | - Tiean Zhou
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
- Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China
| | - Fushen Huang
- Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China
- College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, China
| | - Jinjun Chen
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
- Hunan Provincial Engineering Technology Research Center for Cell Mechanics and Function Analysis, Changsha 410128, China
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5
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Choudhury MI, Benson MA, Sun SX. Trans-epithelial fluid flow and mechanics of epithelial morphogenesis. Semin Cell Dev Biol 2022; 131:146-159. [PMID: 35659163 DOI: 10.1016/j.semcdb.2022.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/22/2022] [Accepted: 05/23/2022] [Indexed: 12/14/2022]
Abstract
Active fluid transport across epithelial monolayers is emerging as a major driving force of tissue morphogenesis in a variety of healthy and diseased systems, as well as during embryonic development. Cells use directional transport of ions and osmotic gradients to drive fluid flow across the cell surface, in the process also building up fluid pressure. The basic physics of this process is described by the osmotic engine model, which also underlies actin-independent cell migration. Recently, the trans-epithelial fluid flux and the hydraulic pressure gradient have been explicitly measured for a variety of cellular and tissue model systems across various species. For the kidney, it was shown that tubular epithelial cells behave as active mechanical fluid pumps: the trans-epithelial fluid flux depends on the hydraulic pressure difference across the epithelial layer. When a stall pressure is reached, the fluid flux vanishes. Hydraulic forces generated from active fluid pumping are important in tissue morphogenesis and homeostasis, and could also underlie multiple morphogenic events seen in other developmental contexts. In this review, we highlight findings that examined the role of trans-epithelial fluid flux and hydraulic pressure gradient in driving tissue-scale morphogenesis. We also review organ pathophysiology due to impaired fluid pumping and the loss of hydraulic pressure sensing at the cellular scale. Finally, we draw an analogy between cellular fluidic pumps and a connected network of water pumps in a city. The dynamics of fluid transport in an active and adaptive network is determined globally at the systemic level, and transport in such a network is best when each pump is operating at its optimal efficiency.
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Affiliation(s)
- Mohammad Ikbal Choudhury
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States; Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, United States; Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, United States
| | - Morgan A Benson
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, United States; Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, United States
| | - Sean X Sun
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, United States; Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, United States; Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21218, United States.
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6
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Yi B, Xu Q, Liu W. An overview of substrate stiffness guided cellular response and its applications in tissue regeneration. Bioact Mater 2022; 15:82-102. [PMID: 35386347 PMCID: PMC8940767 DOI: 10.1016/j.bioactmat.2021.12.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/03/2021] [Accepted: 12/03/2021] [Indexed: 02/06/2023] Open
Abstract
Cell-matrix interactions play a critical role in tissue repair and regeneration. With gradual uncovering of substrate mechanical characteristics that can affect cell-matrix interactions, much progress has been made to unravel substrate stiffness-mediated cellular response as well as its underlying mechanisms. Yet, as a part of cell-matrix interaction biology, this field remains in its infancy, and the detailed molecular mechanisms are still elusive regarding scaffold-modulated tissue regeneration. This review provides an overview of recent progress in the area of the substrate stiffness-mediated cellular responses, including 1) the physical determination of substrate stiffness on cell fate and tissue development; 2) the current exploited approaches to manipulate the stiffness of scaffolds; 3) the progress of recent researches to reveal the role of substrate stiffness in cellular responses in some representative tissue-engineered regeneration varying from stiff tissue to soft tissue. This article aims to provide an up-to-date overview of cell mechanobiology research in substrate stiffness mediated cellular response and tissue regeneration with insightful information to facilitate interdisciplinary knowledge transfer and enable the establishment of prognostic markers for the design of suitable biomaterials. Substrate stiffness physically determines cell fate and tissue development. Rational design of scaffolds requires the understanding of cell-matrix interactions. Substrate stiffness depends on scaffold molecular-constituent-structure interaction. Substrate stiffness-mediated cellular responses vary in different tissues.
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7
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Sri-Ranjan K, Sanchez-Alonso JL, Swiatlowska P, Rothery S, Novak P, Gerlach S, Koeninger D, Hoffmann B, Merkel R, Stevens MM, Sun SX, Gorelik J, Braga VMM. Intrinsic cell rheology drives junction maturation. Nat Commun 2022; 13:4832. [PMID: 35977954 PMCID: PMC9385638 DOI: 10.1038/s41467-022-32102-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 07/15/2022] [Indexed: 12/02/2022] Open
Abstract
A fundamental property of higher eukaryotes that underpins their evolutionary success is stable cell-cell cohesion. Yet, how intrinsic cell rheology and stiffness contributes to junction stabilization and maturation is poorly understood. We demonstrate that localized modulation of cell rheology governs the transition of a slack, undulated cell-cell contact (weak adhesion) to a mature, straight junction (optimal adhesion). Cell pairs confined on different geometries have heterogeneous elasticity maps and control their own intrinsic rheology co-ordinately. More compliant cell pairs grown on circles have slack contacts, while stiffer triangular cell pairs favour straight junctions with flanking contractile thin bundles. Counter-intuitively, straighter cell-cell contacts have reduced receptor density and less dynamic junctional actin, suggesting an unusual adaptive mechano-response to stabilize cell-cell adhesion. Our modelling informs that slack junctions arise from failure of circular cell pairs to increase their own intrinsic stiffness and resist the pressures from the neighbouring cell. The inability to form a straight junction can be reversed by increasing mechanical stress artificially on stiffer substrates. Our data inform on the minimal intrinsic rheology to generate a mature junction and provide a springboard towards understanding elements governing tissue-level mechanics.
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Affiliation(s)
- K Sri-Ranjan
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK
| | - J L Sanchez-Alonso
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK
| | - P Swiatlowska
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK
| | - S Rothery
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK
| | - P Novak
- School of Engineering and Materials Science, Queen Mary University, London, UK
| | - S Gerlach
- Institute of Biological Information Processing, IBI-2: Mechanobiology, Julich, Germany
| | - D Koeninger
- Institute of Biological Information Processing, IBI-2: Mechanobiology, Julich, Germany
| | - B Hoffmann
- Institute of Biological Information Processing, IBI-2: Mechanobiology, Julich, Germany
| | - R Merkel
- Institute of Biological Information Processing, IBI-2: Mechanobiology, Julich, Germany
| | - M M Stevens
- Department of Materials, Department of Bioengineering and Institute of Biomedical Engineering Imperial College London, London, UK
| | - S X Sun
- Department of Mechanical Engineering and Institute of NanoBioTechnology, Johns Hopkins University, Baltimore Maryland, USA
| | - J Gorelik
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
| | - Vania M M Braga
- National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London, UK.
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8
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Losick VP, Duhaime LG. The endocycle restores tissue tension in the Drosophila abdomen post wound repair. Cell Rep 2021; 37:109827. [PMID: 34644579 PMCID: PMC8567445 DOI: 10.1016/j.celrep.2021.109827] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/16/2021] [Accepted: 09/22/2021] [Indexed: 01/04/2023] Open
Abstract
Polyploidy frequently arises in response to injury, aging, and disease. Despite its prevalence, major gaps exist in our understanding of how polyploid cells alter tissue function. In the adult Drosophila epithelium, wound healing is dependent on the generation of multinucleated polyploid cells resulting in a permanent change in the epithelial architecture. Here, we study how the wound-induced polyploid cells affect tissue function by altering epithelial mechanics. The mechanosensor nonmuscle myosin II is activated and upregulated in wound-induced polyploid cells and persists after healing completes. Polyploidy enhances relative epithelial tension, which is dependent on the endocycle and not cell fusion post injury. Remarkably, the enhanced epithelial tension mimics the relative tension of the lateral muscle fibers, which are permanently severed by the injury. As a result, we found that the wound-induced polyploid cells remodel the epithelium to maintain fly abdominal movements, which may help compensate for lost tissue tension. Losick and Duhaime show that the generation of polyploid cells by the endocycle induces myosin expression resulting in enhanced epithelial tension after wound repair. This change in epithelial mechanics appears to compensate for the permanent loss of muscle fibers, which is necessary for efficient abdominal bending in the fruit fly.
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Affiliation(s)
- Vicki P Losick
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA.
| | - Levi G Duhaime
- Biology Department, Boston College, Chestnut Hill, MA 02467, USA
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9
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Wohl I, Sherman E. Reducing Myosin II and ATP-Dependent Mechanical Activity Increases Order and Stability of Intracellular Organelles. Int J Mol Sci 2021; 22:10369. [PMID: 34638710 PMCID: PMC8508806 DOI: 10.3390/ijms221910369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 09/22/2021] [Accepted: 09/23/2021] [Indexed: 11/16/2022] Open
Abstract
Organization of intracellular content is affected by multiple simultaneous processes, including diffusion in a viscoelastic and structured environment, intracellular mechanical work and vibrations. The combined effects of these processes on intracellular organization are complex and remain poorly understood. Here, we studied the organization and dynamics of a free Ca++ probe as a small and mobile tracer in live T cells. Ca++, highlighted by Fluo-4, is localized in intracellular organelles. Inhibiting intracellular mechanical work by myosin II through blebbistatin treatment increased cellular dis-homogeneity of Ca++-rich features in length scale < 1.1 μm. We detected a similar effect in cells imaged by label-free bright-field (BF) microscopy, in mitochondria-highlighted cells and in ATP-depleted cells. Blebbistatin treatment also reduced the dynamics of the Ca++-rich features and generated prominent negative temporal correlations in their signals. Following Guggenberger et al. and numerical simulations, we suggest that diffusion in the viscoelastic and confined medium of intracellular organelles may promote spatial dis-homogeneity and stability of their content. This may be revealed only after inhibiting intracellular mechanical work and related cell vibrations. Our described mechanisms may allow the cell to control its organization via balancing its viscoelasticity and mechanical activity, with implications to cell physiology in health and disease.
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Affiliation(s)
| | - Eilon Sherman
- Racah Institute of Physics, The Hebrew University, Jerusalem 9190401, Israel;
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10
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Melo PN, Souza da Silveira M, Mendes Pinto I, Relvas JB. Morphofunctional programming of microglia requires distinct roles of type II myosins. Glia 2021; 69:2717-2738. [PMID: 34329508 DOI: 10.1002/glia.24067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 11/05/2022]
Abstract
The ramified morphology of microglia and the dynamics of their membrane protrusions are essential for their functions in central nervous system development, homeostasis, and disease. Although their ability to change and control shape critically depends on the actin and actomyosin cytoskeleton, the underlying regulatory mechanisms remain largely unknown. In this study, we systematically analyzed the actomyosin cytoskeleton and regulators downstream of the small GTPase RhoA in the control of microglia shape and function. Our results reveal that (i) Myh9 controls cortical tension levels and affects microglia protrusion formation, (ii) cofilin-mediated maintenance of actin turnover regulates microglia protrusion extension, and (iii) Myh10 influences microglia inflammatory activation. Overall we uncover molecular pathways that regulate microglia morphology and identify type-II myosins as important regulators of microglia biology with differential roles in the control of cell shape (Myh9) and functions (Myh10).
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Affiliation(s)
- Pedro Neves Melo
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal.,Graduate Programme in Areas of Basic and Applied Biology (GABBA), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Mariana Souza da Silveira
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal.,Instituto de Biofísica Carlos Chagas Filho (IBCCF), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Inês Mendes Pinto
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal.,Life Sciences, International Iberian Nanotechnology Laboratory (INL), Braga, Portugal
| | - João Bettencourt Relvas
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal.,Department of Biomedicine, Faculty of Medicine, University of Porto, Porto, Portugal
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11
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Kučera O, Siahaan V, Janda D, Dijkstra SH, Pilátová E, Zatecka E, Diez S, Braun M, Lansky Z. Anillin propels myosin-independent constriction of actin rings. Nat Commun 2021; 12:4595. [PMID: 34321459 PMCID: PMC8319318 DOI: 10.1038/s41467-021-24474-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/21/2021] [Indexed: 02/07/2023] Open
Abstract
Constriction of the cytokinetic ring, a circular structure of actin filaments, is an essential step during cell division. Mechanical forces driving the constriction are attributed to myosin motor proteins, which slide actin filaments along each other. However, in multiple organisms, ring constriction has been reported to be myosin independent. How actin rings constrict in the absence of motor activity remains unclear. Here, we demonstrate that anillin, a non-motor actin crosslinker, indispensable during cytokinesis, autonomously propels the contractility of actin bundles. Anillin generates contractile forces of tens of pico-Newtons to maximise the lengths of overlaps between bundled actin filaments. The contractility is enhanced by actin disassembly. When multiple actin filaments are arranged into a ring, this contractility leads to ring constriction. Our results indicate that passive actin crosslinkers can substitute for the activity of molecular motors to generate contractile forces in a variety of actin networks, including the cytokinetic ring.
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Affiliation(s)
- Ondřej Kučera
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia ,grid.5583.b0000 0001 2299 8025Present Address: CytoMorpho Lab, Laboratoire Physiologie Cellulaire & Végétale, Institut de recherche interdisciplinaire de Grenoble, Commissariat à l’énergie atomique et aux énergies alternatives (CEA), Grenoble, France
| | - Valerie Siahaan
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Daniel Janda
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Sietske H. Dijkstra
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Eliška Pilátová
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Eva Zatecka
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Stefan Diez
- grid.4488.00000 0001 2111 7257B CUBE – Center for Molecular Bioengineering, TU Dresden, Dresden, Germany ,grid.419537.d0000 0001 2113 4567Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany ,grid.4488.00000 0001 2111 7257Cluster of Excellence Physics of Life, Technische Universität Dresden, Dresden, Germany
| | - Marcus Braun
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
| | - Zdenek Lansky
- grid.418095.10000 0001 1015 3316Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, Vestec, Prague West, Czechia
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12
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Flores-Muñoz C, Maripillán J, Vásquez-Navarrete J, Novoa-Molina J, Ceriani R, Sánchez HA, Abbott AC, Weinstein-Oppenheimer C, Brown DI, Cárdenas AM, García IE, Martínez AD. Restraint of Human Skin Fibroblast Motility, Migration, and Cell Surface Actin Dynamics, by Pannexin 1 and P2X7 Receptor Signaling. Int J Mol Sci 2021; 22:1069. [PMID: 33499026 PMCID: PMC7865282 DOI: 10.3390/ijms22031069] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 01/01/2023] Open
Abstract
Wound healing is a dynamic process required to maintain skin integrity and which relies on the precise migration of different cell types. A key molecule that regulates this process is ATP. However, the mechanisms involved in extracellular ATP management are poorly understood, particularly in the human dermis. Here, we explore the role, in human fibroblast migration during wound healing, of Pannexin 1 channels and their relationship with purinergic signals and in vivo cell surface filamentous actin dynamics. Using siRNA against Panx isoforms and different Panx1 channel inhibitors, we demonstrate in cultured human dermal fibroblasts that the absence or inhibition of Panx1 channels accelerates cell migration, increases single-cell motility, and promotes actin redistribution. These changes occur through a mechanism that involves the release of ATP to the extracellular space through a Panx1-dependent mechanism and the activation of the purinergic receptor P2X7. Together, these findings point to a pivotal role of Panx1 channels in skin fibroblast migration and suggest that these channels could be a useful pharmacological target to promote damaged skin healing.
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Affiliation(s)
- Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Joel Novoa-Molina
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ricardo Ceriani
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Helmuth A. Sánchez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Ana C. Abbott
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Caroline Weinstein-Oppenheimer
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile;
- Centro de Investigación Farmacopea Chilena, Valparaíso 2360102, Chile
| | - Donald I. Brown
- Laboratorio de Biología de la Reproducción y del Desarrollo, Instituto de Biología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2340000, Chile;
| | - Ana María Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
| | - Isaac E. García
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
- Laboratorio de Fisiología Molecular y Biofísica, Facultad de Odontología, Universidad de Valparaíso, Valparaíso 2360004, Chile
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Instituto de Neurociencia, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (C.F.-M.); (J.M.); (J.V.-N.); (J.N.-M.); (R.C.); (H.A.S.); (A.C.A.); (A.M.C.); (I.E.G.)
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13
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Naqvi SM, McNamara LM. Stem Cell Mechanobiology and the Role of Biomaterials in Governing Mechanotransduction and Matrix Production for Tissue Regeneration. Front Bioeng Biotechnol 2020; 8:597661. [PMID: 33381498 PMCID: PMC7767888 DOI: 10.3389/fbioe.2020.597661] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Mechanobiology has underpinned many scientific advances in understanding how biophysical and biomechanical cues regulate cell behavior by identifying mechanosensitive proteins and specific signaling pathways within the cell that govern the production of proteins necessary for cell-based tissue regeneration. It is now evident that biophysical and biomechanical stimuli are as crucial for regulating stem cell behavior as biochemical stimuli. Despite this, the influence of the biophysical and biomechanical environment presented by biomaterials is less widely accounted for in stem cell-based tissue regeneration studies. This Review focuses on key studies in the field of stem cell mechanobiology, which have uncovered how matrix properties of biomaterial substrates and 3D scaffolds regulate stem cell migration, self-renewal, proliferation and differentiation, and activation of specific biological responses. First, we provide a primer of stem cell biology and mechanobiology in isolation. This is followed by a critical review of key experimental and computational studies, which have unveiled critical information regarding the importance of the biophysical and biomechanical cues for stem cell biology. This review aims to provide an informed understanding of the intrinsic role that physical and mechanical stimulation play in regulating stem cell behavior so that researchers may design strategies that recapitulate the critical cues and develop effective regenerative medicine approaches.
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Affiliation(s)
- S M Naqvi
- Mechanobiology and Medical Device Research Group, Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - L M McNamara
- Mechanobiology and Medical Device Research Group, Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
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14
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Li Y, Konstantopoulos K, Zhao R, Mori Y, Sun SX. The importance of water and hydraulic pressure in cell dynamics. J Cell Sci 2020; 133:133/20/jcs240341. [PMID: 33087485 DOI: 10.1242/jcs.240341] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
All mammalian cells live in the aqueous medium, yet for many cell biologists, water is a passive arena in which proteins are the leading players that carry out essential biological functions. Recent studies, as well as decades of previous work, have accumulated evidence to show that this is not the complete picture. Active fluxes of water and solutes of water can play essential roles during cell shape changes, cell motility and tissue function, and can generate significant mechanical forces. Moreover, the extracellular resistance to water flow, known as the hydraulic resistance, and external hydraulic pressures are important mechanical modulators of cell polarization and motility. For the cell to maintain a consistent chemical environment in the cytoplasm, there must exist an intricate molecular system that actively controls the cell water content as well as the cytoplasmic ionic content. This system is difficult to study and poorly understood, but ramifications of which may impact all aspects of cell biology from growth to metabolism to development. In this Review, we describe how mammalian cells maintain the cytoplasmic water content and how water flows across the cell surface to drive cell movement. The roles of mechanical forces and hydraulic pressure during water movement are explored.
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Affiliation(s)
- Yizeng Li
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Mechanical Engineering, Kennesaw State University. Marietta, GA 30060, USA
| | - Konstantinos Konstantopoulos
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.,Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Runchen Zhao
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.,Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yoichiro Mori
- Department of Mathematics and Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sean X Sun
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA .,Institute of NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21218, USA
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15
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Argentati C, Morena F, Tortorella I, Bazzucchi M, Porcellati S, Emiliani C, Martino S. Insight into Mechanobiology: How Stem Cells Feel Mechanical Forces and Orchestrate Biological Functions. Int J Mol Sci 2019; 20:E5337. [PMID: 31717803 PMCID: PMC6862138 DOI: 10.3390/ijms20215337] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/23/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
The cross-talk between stem cells and their microenvironment has been shown to have a direct impact on stem cells' decisions about proliferation, growth, migration, and differentiation. It is well known that stem cells, tissues, organs, and whole organisms change their internal architecture and composition in response to external physical stimuli, thanks to cells' ability to sense mechanical signals and elicit selected biological functions. Likewise, stem cells play an active role in governing the composition and the architecture of their microenvironment. Is now being documented that, thanks to this dynamic relationship, stemness identity and stem cell functions are maintained. In this work, we review the current knowledge in mechanobiology on stem cells. We start with the description of theoretical basis of mechanobiology, continue with the effects of mechanical cues on stem cells, development, pathology, and regenerative medicine, and emphasize the contribution in the field of the development of ex-vivo mechanobiology modelling and computational tools, which allow for evaluating the role of forces on stem cell biology.
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Affiliation(s)
- Chiara Argentati
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Francesco Morena
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Ilaria Tortorella
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Martina Bazzucchi
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Serena Porcellati
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Carla Emiliani
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
- CEMIN, Center of Excellence on Nanostructured Innovative Materials, Via del Giochetto, 06126 Perugia, Italy
| | - Sabata Martino
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
- CEMIN, Center of Excellence on Nanostructured Innovative Materials, Via del Giochetto, 06126 Perugia, Italy
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16
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Mangione MC, Gould KL. Molecular form and function of the cytokinetic ring. J Cell Sci 2019; 132:132/12/jcs226928. [PMID: 31209062 DOI: 10.1242/jcs.226928] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Animal cells, amoebas and yeast divide using a force-generating, actin- and myosin-based contractile ring or 'cytokinetic ring' (CR). Despite intensive research, questions remain about the spatial organization of CR components, the mechanism by which the CR generates force, and how other cellular processes are coordinated with the CR for successful membrane ingression and ultimate cell separation. This Review highlights new findings about the spatial relationship of the CR to the plasma membrane and the arrangement of molecules within the CR from studies using advanced microscopy techniques, as well as mechanistic information obtained from in vitro approaches. We also consider advances in understanding coordinated cellular processes that impact the architecture and function of the CR.
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Affiliation(s)
- MariaSanta C Mangione
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
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17
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Mateos-Gil P, Tarazona P, Vélez M. Bacterial cell division: modeling FtsZ assembly and force generation from single filament experimental data. FEMS Microbiol Rev 2019; 43:73-87. [PMID: 30376053 DOI: 10.1093/femsre/fuy039] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/26/2018] [Indexed: 12/24/2022] Open
Abstract
The bacterial cytoskeletal protein FtsZ binds and hydrolyzes GTP, self-aggregates into dynamic filaments and guides the assembly of the septal ring on the inner side of the membrane at midcell. This ring constricts the cell during division and is present in most bacteria. Despite exhaustive studies undertaken in the last 25 years after its discovery, we do not yet know the mechanism by which this GTP-dependent self-aggregating protein exerts force on the underlying membrane. This paper reviews recent experiments and theoretical models proposed to explain FtsZ filament dynamic assembly and force generation. It highlights how recent observations of single filaments on reconstituted model systems and computational modeling are contributing to develop new multiscale models that stress the importance of previously overlooked elements as monomer internal flexibility, filament twist and flexible anchoring to the cell membrane. These elements contribute to understand the rich behavior of these GTP consuming dynamic filaments on surfaces. The aim of this review is 2-fold: (1) to summarize recent multiscale models and their implications to understand the molecular mechanism of FtsZ assembly and force generation and (2) to update theoreticians with recent experimental results.
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Affiliation(s)
- Pablo Mateos-Gil
- Institute of Molecular Biology and Biotechnology, FO.R.T.H, Vassilika Vouton, 70013 Heraklion, Greece
| | - Pedro Tarazona
- Condensed Matter Physics Center (IFIMAC) and Instituto de Ciencia de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Marisela Vélez
- Instituto de Catálisis y Petroleoquímica CSIC, c/ Marie Curie 2, Cantoblanco, 28049 Madrid, Spain
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18
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Hall ET, Hoesing E, Sinkovics E, Verheyen EM. Actomyosin contractility modulates Wnt signaling through adherens junction stability. Mol Biol Cell 2018; 30:411-426. [PMID: 30540525 PMCID: PMC6589568 DOI: 10.1091/mbc.e18-06-0345] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Actomyosin contractility can influence the canonical Wnt signaling pathway in processes like mesoderm differentiation and tissue stiffness during tumorigenesis. We identified that increased nonmuscle myosin II activation and cellular contraction inhibited Wnt target gene transcription in developing Drosophila imaginal disks. Genetic interactions studies were used to show that this effect was due to myosin-induced accumulation of cortical F-actin resulting in clustering and accumulation of E-cadherin to the adherens junctions. This results in E-cadherin titrating any available β-catenin, the Wnt pathway transcriptional coactivator, to the adherens junctions in order to maintain cell-cell adhesion under contraction. We show that decreased levels of cytoplasmic β-catenin result in insufficient nuclear translocation for full Wnt target gene transcription. Previous studies have identified some of these interactions, but we present a thorough analysis using the wing disk epithelium to show the consequences of modulating myosin phosphatase. Our work elucidates a mechanism in which the dynamic promotion of actomyosin contractility refines patterning of Wnt transcription during development and maintenance of epithelial tissue in organisms.
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Affiliation(s)
- Eric T Hall
- Department of Molecular Biology and Biochemistry, Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Elizabeth Hoesing
- Department of Molecular Biology and Biochemistry, Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Endre Sinkovics
- Department of Molecular Biology and Biochemistry, Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Esther M Verheyen
- Department of Molecular Biology and Biochemistry, Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
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19
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Furusato T, Horie F, Matsubayashi HT, Amikura K, Kuruma Y, Ueda T. De Novo Synthesis of Basal Bacterial Cell Division Proteins FtsZ, FtsA, and ZipA Inside Giant Vesicles. ACS Synth Biol 2018; 7:953-961. [PMID: 29510621 DOI: 10.1021/acssynbio.7b00350] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell division is the most dynamic event in the cell cycle. Recently, efforts have been made to reconstruct it using the individual component proteins to obtain a better understanding of the process of self-reproduction of cells. However, such reconstruction studies are frequently hampered by difficulties in preparing membrane-associated proteins. Here we demonstrate a de novo synthesis approach based on a cell-free translation system. Genes for fundamental cell division proteins, FtsZ, FtsA, and ZipA, were expressed inside the lipid compartment of giant vesicles (GVs). The synthesized proteins showed polymerization, membrane localization, and eventually membrane deformation. Notably, we found that this morphological change of the vesicle is forced by only FtsZ and ZipA, which form clusters on the membrane at the vesicle interior. Our cell-free approach provides a platform for studying protein dynamics associated with lipid membrane and paves the way to create a synthetic cell that undergoes self-reproduction.
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Affiliation(s)
- Takumi Furusato
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Fumihiro Horie
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Hideaki T. Matsubayashi
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Kazuaki Amikura
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
| | - Yutetsu Kuruma
- Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1-IE-1, Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Takuya Ueda
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Bldg. FSB-401, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562, Japan
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20
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Cramer LP, Kay RR, Zatulovskiy E. Repellent and Attractant Guidance Cues Initiate Cell Migration by Distinct Rear-Driven and Front-Driven Cytoskeletal Mechanisms. Curr Biol 2018. [PMID: 29526589 PMCID: PMC5863766 DOI: 10.1016/j.cub.2018.02.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Attractive and repulsive cell guidance is essential for animal life and important in disease. Cell migration toward attractants dominates studies [1, 2, 3, 4, 5, 6, 7, 8], but migration away from repellents is important in biology yet relatively little studied [5, 9, 10]. It is widely held that cells initiate migration by protrusion of their front [11, 12, 13, 14, 15], yet this has not been explicitly tested for cell guidance because cell margin displacement at opposite ends of the cell has not been distinguished for any cue. We argue that protrusion of the front, retraction of the rear, or both together could in principle break cell symmetry and start migration in response to guidance cues [16]. Here, we find in the Dictyostelium model [6] that an attractant—cAMP—breaks symmetry by causing protrusion of the front of the cell, whereas its repellent analog—8CPT—breaks symmetry by causing retraction of the rear. Protrusion of the front of these cells in response to cAMP starts with local actin filament assembly, while the delayed retraction of the rear is independent of both myosin II polarization and of motor-based contractility. On the contrary, myosin II accumulates locally in the rear of the cell in response to 8CPT, anticipating retraction and required for it, while local actin assembly is delayed and couples to delayed protrusion at the front. These data reveal an important new concept in the understanding of cell guidance. In attractant, cell front protrusion breaks cell symmetry and starts migration In repellent, cell rear retraction breaks cell symmetry and starts migration Myosin II motor is not required for front-driven migration toward attractant Biased myosin II motor contractility drives rear-driven migration away from repellent
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Affiliation(s)
- Louise P Cramer
- Laboratory of Molecular Cell Biology and Department of Cell and Developmental Biology, Faculty Life Science, UCL, Gower Street, London WC1E 6BT, England, UK.
| | - Robert R Kay
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England, UK
| | - Evgeny Zatulovskiy
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, England, UK
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21
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Bun P, Dmitrieff S, Belmonte JM, Nédélec FJ, Lénárt P. A disassembly-driven mechanism explains F-actin-mediated chromosome transport in starfish oocytes. eLife 2018; 7:31469. [PMID: 29350616 PMCID: PMC5788506 DOI: 10.7554/elife.31469] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/18/2018] [Indexed: 12/12/2022] Open
Abstract
While contraction of sarcomeric actomyosin assemblies is well understood, this is not the case for disordered networks of actin filaments (F-actin) driving diverse essential processes in animal cells. For example, at the onset of meiosis in starfish oocytes a contractile F-actin network forms in the nuclear region transporting embedded chromosomes to the assembling microtubule spindle. Here, we addressed the mechanism driving contraction of this 3D disordered F-actin network by comparing quantitative observations to computational models. We analyzed 3D chromosome trajectories and imaged filament dynamics to monitor network behavior under various physical and chemical perturbations. We found no evidence of myosin activity driving network contractility. Instead, our observations are well explained by models based on a disassembly-driven contractile mechanism. We reconstitute this disassembly-based contractile system in silico revealing a simple architecture that robustly drives chromosome transport to prevent aneuploidy in the large oocyte, a prerequisite for normal embryonic development.
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Affiliation(s)
- Philippe Bun
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Serge Dmitrieff
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Julio M Belmonte
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - François J Nédélec
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Péter Lénárt
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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22
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Abstract
D'Arcy Thompson was a proponent of applying mathematical and physical principles to biological systems, an approach that is becoming increasingly common in developmental biology. Indeed, the recent integration of quantitative experimental data, force measurements and mathematical modeling has changed our understanding of morphogenesis - the shaping of an organism during development. Emerging evidence suggests that the subcellular organization of contractile cytoskeletal networks plays a key role in force generation, while on the tissue level the spatial organization of forces determines the morphogenetic output. Inspired by D'Arcy Thompson's On Growth and Form, we review our current understanding of how biological forms are created and maintained by the generation and organization of contractile forces at the cell and tissue levels. We focus on recent advances in our understanding of how cells actively sculpt tissues and how forces are involved in specific morphogenetic processes.
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Affiliation(s)
- Natalie C Heer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Adam C Martin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
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23
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McFaul CMJ, Fernandez-Gonzalez R. Shape of my heart: Cell-cell adhesion and cytoskeletal dynamics during Drosophila cardiac morphogenesis. Exp Cell Res 2017; 358:65-70. [PMID: 28389210 DOI: 10.1016/j.yexcr.2017.03.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 03/27/2017] [Indexed: 11/25/2022]
Abstract
The fruit fly Drosophila melanogaster has recently emerged as an excellent system to investigate the genetics of cardiovascular development and disease. Drosophila provides an inexpensive and genetically-tractable in vivo system with a large number of conserved features. In addition, the Drosophila embryo is transparent, and thus amenable to time-lapse fluorescence microscopy, as well as biophysical and pharmacological manipulations. One of the conserved aspects of heart development from Drosophila to humans is the initial assembly of a tube. Here, we review the cellular behaviours and molecular dynamics important for the initial steps of heart morphogenesis in Drosophila, with particular emphasis on the cell-cell adhesion and cytoskeletal networks that cardiac precursors use to move, coordinate their migration, interact with other tissues and eventually sculpt a beating heart.
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Affiliation(s)
- Christopher M J McFaul
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Rodrigo Fernandez-Gonzalez
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Ted Rogers Centre for Heart Research, University of Toronto, Toronto, ON M5G 1M1, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
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24
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Tao J, Li Y, Vig DK, Sun SX. Cell mechanics: a dialogue. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:036601. [PMID: 28129208 PMCID: PMC5518794 DOI: 10.1088/1361-6633/aa5282] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Under the microscope, eukaryotic animal cells can adopt a variety of different shapes and sizes. These cells also move and deform, and the physical mechanisms driving these movements and shape changes are important in fundamental cell biology, tissue mechanics, as well as disease biology. This article reviews some of the basic mechanical concepts in cells, emphasizing continuum mechanics description of cytoskeletal networks and hydrodynamic flows across the cell membrane. We discuss how cells can generate movement and shape changes by controlling mass fluxes at the cell boundary. These mass fluxes can come from polymerization/depolymerization of actin cytoskeleton, as well as osmotic and hydraulic pressure-driven flow of water across the cell membrane. By combining hydraulic pressure control with force balance conditions at the cell surface, we discuss a quantitative mechanism of cell shape and volume control. The broad consequences of this model on cell mechanosensation and tissue mechanics are outlined.
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Affiliation(s)
- Jiaxiang Tao
- Departments of Mechanical Engineering, Johns Hopkins University, Baltimore MD, United States of America
- Physical Sciences in Oncology Center, Johns Hopkins University, Baltimore MD, United States of America
| | - Yizeng Li
- Departments of Mechanical Engineering, Johns Hopkins University, Baltimore MD, United States of America
- Institute of NanoBioTechnology, Johns Hopkins University, Baltimore MD, United States of America
| | - Dhruv K Vig
- Departments of Mechanical Engineering, Johns Hopkins University, Baltimore MD, United States of America
- Institute of NanoBioTechnology, Johns Hopkins University, Baltimore MD, United States of America
| | - Sean X Sun
- Departments of Mechanical Engineering, Johns Hopkins University, Baltimore MD, United States of America
- Biomedical Engineering, Johns Hopkins University, Baltimore MD, United States of America
- Physical Sciences in Oncology Center, Johns Hopkins University, Baltimore MD, United States of America
- Institute of NanoBioTechnology, Johns Hopkins University, Baltimore MD, United States of America
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25
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Vasquez CG, Heissler SM, Billington N, Sellers JR, Martin AC. Drosophila non-muscle myosin II motor activity determines the rate of tissue folding. eLife 2016; 5. [PMID: 28035903 PMCID: PMC5201417 DOI: 10.7554/elife.20828] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 12/08/2016] [Indexed: 12/15/2022] Open
Abstract
Non-muscle cell contractility is critical for tissues to adopt shape changes. Although, the non-muscle myosin II holoenzyme (myosin) is a molecular motor that powers contraction of actin cytoskeleton networks, recent studies have questioned the importance of myosin motor activity cell and tissue shape changes. Here, combining the biochemical analysis of enzymatic and motile properties for purified myosin mutants with in vivo measurements of apical constriction for the same mutants, we show that in vivo constriction rate scales with myosin motor activity. We show that so-called phosphomimetic mutants of the Drosophila regulatory light chain (RLC) do not mimic the phosphorylated RLC state in vitro. The defect in the myosin motor activity in these mutants is evident in developing Drosophila embryos where tissue recoil following laser ablation is decreased compared to wild-type tissue. Overall, our data highlights that myosin activity is required for rapid cell contraction and tissue folding in developing Drosophila embryos. DOI:http://dx.doi.org/10.7554/eLife.20828.001
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Affiliation(s)
- Claudia G Vasquez
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Neil Billington
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Adam C Martin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
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26
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Livne A, Geiger B. The inner workings of stress fibers - from contractile machinery to focal adhesions and back. J Cell Sci 2016; 129:1293-304. [PMID: 27037413 DOI: 10.1242/jcs.180927] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ventral stress fibers and focal adhesions are physically coupled structures that play key roles in cellular mechanics and force sensing. The tight functional interdependence between the two is manifested not only by their apparent proximity but also by the fact that ventral stress fibers and focal adhesions are simultaneously diminished upon actomyosin relaxation, and grow when subjected to external stretching. However, whereas the apparent co-regulation of the two structures is well-documented, the underlying mechanisms remains poorly understood. In this Commentary, we discuss some of the fundamental, yet still open questions regarding ventral stress fiber structure, its force-dependent assembly, as well as its capacity to generate force. We also challenge the common approach - i.e. ventral stress fibers are variants of the well-studied striated or smooth muscle machinery - by presenting and critically discussing alternative venues. By highlighting some of the less-explored aspects of the interplay between stress fibers and focal adhesions, we hope that this Commentary will encourage further investigation in this field.
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Affiliation(s)
- Ariel Livne
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Benjamin Geiger
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 7610001, Israel
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27
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Martin AC. Embryonic ring closure: Actomyosin rings do the two-step. J Cell Biol 2016; 215:301-303. [PMID: 27799371 PMCID: PMC5100299 DOI: 10.1083/jcb.201610061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 11/22/2022] Open
Abstract
Martin discusses work by Xue and Sokac defining the motor requirements for ring closure during cellularization in Drosophila. Actomyosin rings drive numerous closure processes, but the mechanisms by which they contract are still poorly understood. In this issue, Xue and Sokac (2016. J. Cell Biol.http://dx.doi.org/10.1083/jcb.201608025) show that actomyosin ring closure during Drosophila melanogaster cellularization uses two steps, only one of which involves Myosin-2.
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Affiliation(s)
- Adam C Martin
- Massachusetts Institute of Technology, Cambridge, MA 02139
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28
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Cheffings T, Burroughs N, Balasubramanian M. Actomyosin Ring Formation and Tension Generation in Eukaryotic Cytokinesis. Curr Biol 2016; 26:R719-R737. [DOI: 10.1016/j.cub.2016.06.071] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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29
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Johann D, Goswami D, Kruse K. Assembly of bipolar microtubule structures by passive cross-linkers and molecular motors. Phys Rev E 2016; 93:062415. [PMID: 27415306 DOI: 10.1103/physreve.93.062415] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Indexed: 12/14/2022]
Abstract
During cell division, sister chromatids are segregated by the mitotic spindle, a bipolar assembly of interdigitating antiparallel polar filaments called microtubules. The spindle contains the midzone, a stable region of overlapping antiparallel microtubules, that is essential for maintaining bipolarity. Although a lot is known about the molecular players involved, the mechanism underlying midzone formation and maintenance is still poorly understood. We study the interaction of polar filaments that are cross-linked by molecular motors moving directionally and by passive cross-linkers diffusing along microtubules. Using a particle-based stochastic model, we find that the interplay of motors and passive cross-linkers can generate a stable finite overlap between a pair of antiparallel polar filaments. We develop a mean-field theory to study this mechanism in detail and investigate the influence of steric interactions between motors and passive cross-linkers on the overlap dynamics. In the presence of interspecies steric interactions, passive cross-linkers mimic the behavior of molecular motors and stable finite overlaps are generated even for non-cross-linking motors. Finally, we develop a mean-field theory for a bundle of aligned polar filaments and show that they can self-organize into a spindlelike pattern. Our work suggests possible ways as to how cells can generate spindle midzones and control their extensions.
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Affiliation(s)
- D Johann
- Theoretische Physik, Universität des Saarlandes, Postfach 151150, 66041 Saarbrücken, Germany
| | - D Goswami
- Theoretische Physik, Universität des Saarlandes, Postfach 151150, 66041 Saarbrücken, Germany
| | - K Kruse
- Theoretische Physik, Universität des Saarlandes, Postfach 151150, 66041 Saarbrücken, Germany
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30
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Abstract
Actomyosin-mediated contractility is a highly conserved mechanism for generating mechanical stress in animal cells and underlies muscle contraction, cell migration, cell division and tissue morphogenesis. Whereas actomyosin-mediated contractility in striated muscle is well understood, the regulation of such contractility in non-muscle and smooth muscle cells is less certain. Our increased understanding of the mechanics of actomyosin arrays that lack sarcomeric organization has revealed novel modes of regulation and force transmission. This work also provides an example of how diverse mechanical behaviours at cellular scales can arise from common molecular components, underscoring the need for experiments and theories to bridge the molecular to cellular length scales.
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31
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Escuin S, Vernay B, Savery D, Gurniak CB, Witke W, Greene NDE, Copp AJ. Rho-kinase-dependent actin turnover and actomyosin disassembly are necessary for mouse spinal neural tube closure. J Cell Sci 2015; 128:2468-81. [PMID: 26040287 PMCID: PMC4510849 DOI: 10.1242/jcs.164574] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 05/28/2015] [Indexed: 12/24/2022] Open
Abstract
The cytoskeleton is widely considered essential for neurulation, yet the mouse spinal neural tube can close despite genetic and non-genetic disruption of the cytoskeleton. To investigate this apparent contradiction, we applied cytoskeletal inhibitors to mouse embryos in culture. Preventing actomyosin cross-linking, F-actin assembly or myosin II contractile activity did not disrupt spinal closure. In contrast, inhibiting Rho kinase (ROCK, for which there are two isoforms ROCK1 and ROCK2) or blocking F-actin disassembly prevented closure, with apical F-actin accumulation and adherens junction disturbance in the neuroepithelium. Cofilin-1-null embryos yielded a similar phenotype, supporting the hypothesis that there is a key role for actin turnover. Co-exposure to Blebbistatin rescued the neurulation defects caused by RhoA inhibition, whereas an inhibitor of myosin light chain kinase, ML-7, had no such effect. We conclude that regulation of RhoA, Rho kinase, LIM kinase and cofilin signalling is necessary for spinal neural tube closure through precise control of neuroepithelial actin turnover and actomyosin disassembly. In contrast, actomyosin assembly and myosin ATPase activity are not limiting for closure. Summary: Actomyosin assembly and myosin ATPase activity are not essential for mouse spinal neurulation. However, the ROCK–LIMK–cofilin pathway, which controls actin turnover and actomyosin disassembly, is necessary.
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Affiliation(s)
- Sarah Escuin
- Newlife Birth Defects Research Centre, Institute of Child Health, University College London, WC1N 1EH, UK
| | - Bertrand Vernay
- Newlife Birth Defects Research Centre, Institute of Child Health, University College London, WC1N 1EH, UK
| | - Dawn Savery
- Newlife Birth Defects Research Centre, Institute of Child Health, University College London, WC1N 1EH, UK
| | - Christine B Gurniak
- Cell Migration Unit, Institut für Genetik, Universität Bonn, 53115 Bonn, Germany
| | - Walter Witke
- Cell Migration Unit, Institut für Genetik, Universität Bonn, 53115 Bonn, Germany
| | - Nicholas D E Greene
- Newlife Birth Defects Research Centre, Institute of Child Health, University College London, WC1N 1EH, UK
| | - Andrew J Copp
- Newlife Birth Defects Research Centre, Institute of Child Health, University College London, WC1N 1EH, UK
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32
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Lansky Z, Braun M, Lüdecke A, Schlierf M, ten Wolde P, Janson M, Diez S. Diffusible Crosslinkers Generate Directed Forces in Microtubule Networks. Cell 2015; 160:1159-68. [DOI: 10.1016/j.cell.2015.01.051] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/11/2014] [Accepted: 01/06/2015] [Indexed: 10/23/2022]
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Miklavc P, Ehinger K, Sultan A, Felder T, Paul P, Gottschalk KE, Frick M. Actin depolymerisation and crosslinking join forces with myosin II to contract actin coats on fused secretory vesicles. J Cell Sci 2015; 128:1193-203. [PMID: 25637593 PMCID: PMC4359923 DOI: 10.1242/jcs.165571] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In many secretory cells actin and myosin are specifically recruited to the surface of secretory granules following their fusion with the plasma membrane. Actomyosin-dependent compression of fused granules is essential to promote active extrusion of cargo. However, little is known about molecular mechanisms regulating actin coat formation and contraction. Here, we provide a detailed kinetic analysis of the molecules regulating actin coat contraction on fused lamellar bodies in primary alveolar type II cells. We demonstrate that ROCK1 and myosin light chain kinase 1 (MLCK1, also known as MYLK) translocate to fused lamellar bodies and activate myosin II on actin coats. However, myosin II activity is not sufficient for efficient actin coat contraction. In addition, cofilin-1 and α-actinin translocate to actin coats. ROCK1-dependent regulated actin depolymerisation by cofilin-1 in cooperation with actin crosslinking by α-actinin is essential for complete coat contraction. In summary, our data suggest a complementary role for regulated actin depolymerisation and crosslinking, and myosin II activity, to contract actin coats and drive secretion.
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Affiliation(s)
- Pika Miklavc
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Konstantin Ehinger
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Ayesha Sultan
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Tatiana Felder
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Patrick Paul
- Institute for Experimental Physics, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Kay-Eberhard Gottschalk
- Institute for Experimental Physics, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
| | - Manfred Frick
- Department of General Physiology, University of Ulm, Albert-Einstein Allee 11, 89081 Ulm, Germany
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34
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Bidone TC, Tang H, Vavylonis D. Dynamic network morphology and tension buildup in a 3D model of cytokinetic ring assembly. Biophys J 2014; 107:2618-28. [PMID: 25468341 DOI: 10.1016/j.bpj.2014.10.034] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/15/2014] [Accepted: 10/23/2014] [Indexed: 11/19/2022] Open
Abstract
During fission yeast cytokinesis, actin filaments nucleated by cortical formin Cdc12 are captured by myosin motors bound to a band of cortical nodes and bundled by cross-linking proteins. The myosin motors exert forces on the actin filaments, resulting in a net pulling of the nodes into a contractile ring, while cross-linking interactions help align actin filaments and nodes into a single bundle. We used these mechanisms in a three-dimensional computational model of contractile ring assembly, with semiflexible actin filaments growing from formins at cortical nodes, capturing of filaments by neighboring nodes, and cross-linking among filaments through attractive interactions. The model was used to predict profiles of actin filament density at the cell cortex, morphologies of condensing node-filament networks, and regimes of cortical tension by varying the node pulling force and strength of cross-linking among actin filaments. Results show that cross-linking interactions can lead to confinement of actin filaments at the simulated cortical boundary. We show that the ring-formation region in parameter space lies close to regions leading to clumps, meshworks or double rings, and stars/cables. Since boundaries between regions are not sharp, transient structures that resemble clumps, stars, and meshworks can appear in the process of ring assembly. These results are consistent with prior experiments with mutations in actin-filament turnover regulators, myosin motor activity, and changes in the concentration of cross-linkers that alter the morphology of the condensing network. Transient star shapes appear in some simulations, and these morphologies offer an explanation for star structures observed in prior experimental images. Finally, we quantify tension along actin filaments and forces on nodes during ring assembly and show that the mechanisms describing ring assembly can also drive ring constriction once the ring is formed.
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Affiliation(s)
- Tamara C Bidone
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania
| | - Haosu Tang
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania
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35
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Masedunskas A, Appaduray M, Hardeman EC, Gunning PW. What makes a model system great? INTRAVITAL 2014. [DOI: 10.4161/intv.26287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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36
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Mierke CT. The fundamental role of mechanical properties in the progression of cancer disease and inflammation. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2014; 77:076602. [PMID: 25006689 DOI: 10.1088/0034-4885/77/7/076602] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The role of mechanical properties in cancer disease and inflammation is still underinvestigated and even ignored in many oncological and immunological reviews. In particular, eight classical hallmarks of cancer have been proposed, but they still ignore the mechanics behind the processes that facilitate cancer progression. To define the malignant transformation of neoplasms and finally reveal the functional pathway that enables cancer cells to promote cancer progression, these classical hallmarks of cancer require the inclusion of specific mechanical properties of cancer cells and their microenvironment such as the extracellular matrix as well as embedded cells such as fibroblasts, macrophages or endothelial cells. Thus, this review will present current cancer research from a biophysical point of view and will therefore focus on novel physical aspects and biophysical methods to investigate the aggressiveness of cancer cells and the process of inflammation. As cancer or immune cells are embedded in a certain microenvironment such as the extracellular matrix, the mechanical properties of this microenvironment cannot be neglected, and alterations of the microenvironment may have an impact on the mechanical properties of the cancer or immune cells. Here, it is highlighted how biophysical approaches, both experimental and theoretical, have an impact on the classical hallmarks of cancer and inflammation. It is even pointed out how these biophysical approaches contribute to the understanding of the regulation of cancer disease and inflammatory responses after tissue injury through physical microenvironmental property sensing mechanisms. The recognized physical signals are transduced into biochemical signaling events that guide cellular responses, such as malignant tumor progression, after the transition of cancer cells from an epithelial to a mesenchymal phenotype or an inflammatory response due to tissue injury. Moreover, cell adaptation to mechanical alterations, in particular the understanding of mechano-coupling and mechano-regulating functions in cell invasion, appears as an important step in cancer progression and inflammatory response to injuries. This may lead to novel insights into cancer disease and inflammatory diseases and will overcome classical views on cancer and inflammation. In addition, this review will discuss how the physics of cancer and inflammation can help to reveal whether cancer cells will invade connective tissue and metastasize or how leukocytes extravasate and migrate through the tissue. In this review, the physical concepts of cancer progression, including the tissue basement membrane a cancer cell is crossing, its invasion and transendothelial migration as well as the basic physical concepts of inflammatory processes and the cellular responses to the mechanical stress of the microenvironment such as external forces and matrix stiffness, are presented and discussed. In conclusion, this review will finally show how physical measurements can improve classical approaches that investigate cancer and inflammatory diseases, and how these physical insights can be integrated into classical tumor biological approaches.
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Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth Science, Institute of Experimental Physics I, Biological Physics Division, University of Leipzig, Linnéstr. 5, 04103 Leipzig, Germany
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37
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Natarajan P, Crothers JM, Rosen JE, Nakada SL, Rakholia M, Okamoto CT, Forte JG, Machen TE. Myosin IIB and F-actin control apical vacuolar morphology and histamine-induced trafficking of H-K-ATPase-containing tubulovesicles in gastric parietal cells. Am J Physiol Gastrointest Liver Physiol 2014; 306:G699-710. [PMID: 24578340 PMCID: PMC3989701 DOI: 10.1152/ajpgi.00316.2013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Selective inhibitors of myosin or actin function and confocal microscopy were used to test the role of an actomyosin complex in controlling morphology, trafficking, and fusion of tubulovesicles (TV) containing H-K-ATPase with the apical secretory canaliculus (ASC) of primary-cultured rabbit gastric parietal cells. In resting cells, myosin IIB and IIC, ezrin, and F-actin were associated with ASC, whereas H-K-ATPase localized to intracellular TV. Histamine caused fusion of TV with ASC and subsequent expansion resulting from HCl and water secretion; F-actin and ezrin remained associated with ASC whereas myosin IIB and IIC appeared to dissociate from ASC and relocalize to the cytoplasm. ML-7 (inhibits myosin light chain kinase) caused ASC of resting cells to collapse and most myosin IIB, F-actin, and ezrin to dissociate from ASC. TV were unaffected by ML-7. Jasplakinolide (stabilizes F-actin) caused ASC to develop large blebs to which actin, myosin II, and ezrin, as well as tubulin, were prominently localized. When added prior to stimulation, ML-7 and jasplakinolide prevented normal histamine-stimulated transformations of ASC/TV and the cytoskeleton, but they did not affect cells that had been previously stimulated with histamine. These results indicate that dynamic pools of actomyosin are required for maintenance of ASC structure in resting cells and for trafficking of TV to ASC during histamine stimulation. However, the dynamic pools of actomyosin are not required once the histamine-stimulated transformation of TV/ASC and cytoskeleton has occurred. These results also show that vesicle trafficking in parietal cells shares mechanisms with similar processes in renal collecting duct cells, neuronal synapses, and skeletal muscle.
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Affiliation(s)
- Paramasivam Natarajan
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - James M. Crothers
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - Jared E. Rosen
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - Stephanie L. Nakada
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - Milap Rakholia
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - Curtis T. Okamoto
- 2Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - John G. Forte
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
| | - Terry E. Machen
- 1Department of Molecular and Cell Biology, University of California, Berkeley, California; and
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38
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Shimizu Y, Kushida Y, Kiriyama S, Nakano K, Numata O. Formation and ingression of division furrow can progress under the inhibitory condition of actin polymerization in ciliate Tetrahymena pyriformis. Zoolog Sci 2014; 30:1044-9. [PMID: 24328456 DOI: 10.2108/zsj.30.1044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In eukaryotic cells that multiply by binary fission, the interaction of actin filaments with myosin II in the contractile ring is widely recognized to generate force for membrane ingression into the cleavage furrow; however, the expression of myosin II is restricted in animals, yeast, fungi, and amoeba (collectively, unikonts). No corresponding motor protein capable of forming mini-filaments that could exert sufficient tension to cleave the cell body is found in bikonts, consisting of planta, algae, and most protozoa; however, cells in some bikont lineages multiply by binary fission, as do animal cells. Of these, the ciliate Tetrahymena is known to form an actin ring beneath the division furrow in cytokinesis. Here, we investigated the role of filamentous actin in the cytokinesis of Tetrahymena pyriformis by treating synchronized dividing cells with an actin-inhibiting drug, Latrunculin-A. Video microscopic observation of live cells undergoing cytokinesis was performed, and contrary to expectation, we found that initiation of furrow ingression and its progress are not suppressed under the inhibitory condition of actin polymerization in Tetrahymena cells. We suggest that an actin filament-independent mechanism of binary fission may have been acquired during the evolution in this organism.
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Affiliation(s)
- Yuhta Shimizu
- Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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39
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Gyger M, Stange R, Kießling TR, Fritsch A, Kostelnik KB, Beck-Sickinger AG, Zink M, Käs JA. Active contractions in single suspended epithelial cells. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 43:11-23. [PMID: 24196420 DOI: 10.1007/s00249-013-0935-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/08/2013] [Accepted: 10/15/2013] [Indexed: 12/12/2022]
Abstract
Investigations of active contractions in tissue cells to date have been focused on cells that exert forces via adhesion sites to substrates or to other cells. In this study we show that also suspended epithelial cells exhibit contractility, revealing that contractions can occur independently of focal adhesions. We employ the Optical Stretcher to measure adhesion-independent mechanical properties of an epithelial cell line transfected with a heat-sensitive cation channel. During stretching the heat transferred to the ion channel causes a pronounced Ca(2+) influx through the plasma membrane that can be blocked by adequate drugs. This way the contractile forces in suspended cells are shown to be partially triggered by Ca(2+) signaling. A phenomenological mathematical model is presented, incorporating a term accounting for the active stress exerted by the cell, which is both necessary and sufficient to describe the observed increase in strain when the Ca(2+) influx is blocked. The median and the shape of the strain distributions depend on the activity of the cells. Hence, it is unlikely that they can be described by a simple Gaussian or log normal distribution, but depend on specific cellular properties such as active contractions. Our results underline the importance of considering activity when measuring cellular mechanical properties even in the absence of measurable contractions. Thus, the presented method to quantify active contractions of suspended cells offers new perspectives for a better understanding of cellular force generation with possible implications for medical diagnosis and therapy.
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Affiliation(s)
- Markus Gyger
- Abteilung für Physik der weichen Materie, Institut für Experimentelle Physik I, Universität Leipzig, Linnéstr. 5, 04103, Leipzig, Germany,
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Fuhs T, Goegler M, Brunner CA, Wolgemuth CW, Kaes JA. Causes of retrograde flow in fish keratocytes. Cytoskeleton (Hoboken) 2013; 71:24-35. [DOI: 10.1002/cm.21151] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 08/05/2013] [Accepted: 10/08/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Thomas Fuhs
- Division of Soft Matter Physics Department of Physics; University of Leipzig; 04103 Leipzig Germany
- Paul Flechsig Institute of Brain Research; University of Leipzig; 04109 Leipzig Germany
| | - Michael Goegler
- Division of Soft Matter Physics Department of Physics; University of Leipzig; 04103 Leipzig Germany
| | - Claudia A. Brunner
- Division of Soft Matter Physics Department of Physics; University of Leipzig; 04103 Leipzig Germany
| | - Charles W. Wolgemuth
- Departments of Physics of Molecular and Cellular Biology; University of Arizona; Tucson Arizona
| | - Josef A. Kaes
- Division of Soft Matter Physics Department of Physics; University of Leipzig; 04103 Leipzig Germany
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Danuser G, Allard J, Mogilner A. Mathematical modeling of eukaryotic cell migration: insights beyond experiments. Annu Rev Cell Dev Biol 2013; 29:501-28. [PMID: 23909278 DOI: 10.1146/annurev-cellbio-101512-122308] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A migrating cell is a molecular machine made of tens of thousands of short-lived and interacting parts. Understanding migration means understanding the self-organization of these parts into a system of functional units. This task is one of tackling complexity: First, the system integrates numerous chemical and mechanical component processes. Second, these processes are connected in feedback interactions and over a large range of spatial and temporal scales. Third, many processes are stochastic, which leads to heterogeneous migration behaviors. Early on in the research of cell migration it became evident that this complexity exceeds human intuition. Thus, the cell migration community has led the charge to build mathematical models that could integrate the diverse experimental observations and measurements in consistent frameworks, first in conceptual and more recently in molecularly explicit models. The main goal of this review is to sift through a series of important conceptual and explicit mathematical models of cell migration and to evaluate their contribution to the field in their ability to integrate critical experimental data.
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Affiliation(s)
- Gaudenz Danuser
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115;
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Mechanism of cell rear retraction in migrating cells. Curr Opin Cell Biol 2013; 25:591-9. [PMID: 23764164 DOI: 10.1016/j.ceb.2013.05.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/26/2013] [Accepted: 05/10/2013] [Indexed: 11/23/2022]
Abstract
For decades, ever growing data on myosin II provides strong evidence that interaction of myosin-II-motor-domain with actin filaments within cells retracts the cell rear during actin-based cell migration. Now it is clear myosin II motor-activity is not the sole force involved. Alternative force-generating mechanisms within cells clearly also exist to power cell rear retraction during actin-based cell migration. Given that nematode sperm cells migrate without actin and without cytoskeletal motor proteins it is perhaps not surprising other types of force power cell rear retraction in actin-based systems. Here, cell rear retraction driven by actin filament depolymerisation, actin filament crosslinking, cell front protrusion and possibly apparent membrane tension and their importance relative to myosin II-motor-based contractility are discussed.
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Physical break-down of the classical view on cancer cell invasion and metastasis. Eur J Cell Biol 2013; 92:89-104. [PMID: 23391781 DOI: 10.1016/j.ejcb.2012.12.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/12/2012] [Accepted: 12/23/2012] [Indexed: 11/23/2022] Open
Abstract
Eight classical hallmarks of cancer have been proposed and are well-defined by using biochemical or molecular genetic methods, but are not yet precisely defined by cellular biophysical processes. To define the malignant transformation of neoplasms and finally reveal the functional pathway, which enables cancer cells to promote cancer progression, these classical hallmarks of cancer require the inclusion of specific biomechanical properties of cancer cells and their microenvironment such as the extracellular matrix and embedded cells such as fibroblasts, macrophages or endothelial cells. Nonetheless a main novel ninth hallmark of cancer is still elusive in classical tumor biological reviews, which is the aspect of physics in cancer disease by the natural selection of an aggressive (highly invasive) subtype of cancer cells. The physical aspects can be analyzed by using state-of-the-art biophysical methods. Thus, this review will present current cancer research in a different light and will focus on novel physical methods to investigate the aggressiveness of cancer cells from a biophysicist's point of view. This may lead to novel insights into cancer disease and will overcome classical views on cancer. In addition, this review will discuss how physics of cancer can help to reveal whether cancer cells will invade connective tissue and metastasize. In particular, this review will point out how physics can improve, break-down or support classical approaches to examine tumor growth even across primary tumor boundaries, the invasion of single or collective cancer cells, transendothelial migration of cancer cells and metastasis in targeted organs. Finally, this review will show how physical measurements can be integrated into classical tumor biological analysis approaches. The insights into physical interactions between cancer cells, the primary tumor and the microenvironment may help to solve some "old" questions in cancer disease progression and may finally lead to novel approaches for development and improvement of cancer diagnostics and therapies.
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Abstract
Much of our knowledge of molecular cellular functions is based on studies with a few number of model organisms that were established during the last 50 years. The social amoeba Dictyostelium discoideum is one such model, and has been particularly useful for the study of cell motility, chemotaxis, phagocytosis, endocytic vesicle traffic, cell adhesion, pattern formation, caspase-independent cell death, and, more recently, autophagy and social evolution. As nonmammalian model of human diseases D. discoideum is a newcomer, yet it has proven to be a powerful genetic and cellular model for investigating host-pathogen interactions and microbial infections, for mitochondrial diseases, and for pharmacogenetic studies. The D. discoideum genome harbors several homologs of human genes responsible for a variety of diseases, -including Chediak-Higashi syndrome, lissencephaly, mucolipidosis, Huntington disease, IBMPFD, and Shwachman-Diamond syndrome. A few genes have already been studied, providing new insights on the mechanism of action of the encoded proteins and in some cases on the defect underlying the disease. The opportunities offered by the organism and its place among the nonmammalian models for human diseases will be discussed.
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Affiliation(s)
- Salvatore Bozzaro
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, Turin, Italy.
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Gayathri P, Fujii T, Møller-Jensen J, van den Ent F, Namba K, Löwe J. A bipolar spindle of antiparallel ParM filaments drives bacterial plasmid segregation. Science 2012; 338:1334-7. [PMID: 23112295 DOI: 10.1126/science.1229091] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To ensure their stable inheritance by daughter cells during cell division, bacterial low-copy-number plasmids make simple DNA segregating machines that use an elongating protein filament between sister plasmids. In the ParMRC system of the Escherichia coli R1 plasmid, ParM, an actinlike protein, forms the spindle between ParRC complexes on sister plasmids. By using a combination of structural work and total internal reflection fluorescence microscopy, we show that ParRC bound and could accelerate growth at only one end of polar ParM filaments, mechanistically resembling eukaryotic formins. The architecture of ParM filaments enabled two ParRC-bound filaments to associate in an antiparallel orientation, forming a bipolar spindle. The spindle elongated as a bundle of at least two antiparallel filaments, thereby pushing two plasmid clusters toward the poles.
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Affiliation(s)
- P Gayathri
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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Balasubramanian MK, Srinivasan R, Huang Y, Ng KH. Comparing contractile apparatus-driven cytokinesis mechanisms across kingdoms. Cytoskeleton (Hoboken) 2012; 69:942-56. [PMID: 23027576 DOI: 10.1002/cm.21082] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/18/2012] [Indexed: 12/13/2022]
Abstract
Cytokinesis is the final stage of the cell cycle during which a cell physically divides into two daughters through the assembly of new membranes (and cell wall in some cases) between the forming daughters. New membrane assembly can either proceed centripetally behind a contractile apparatus, as in the case of prokaryotes, archaea, fungi, and animals or expand centrifugally, as in the case of higher plants. In this article, we compare the mechanisms of cytokinesis in diverse organisms dividing through the use of a contractile apparatus. While an actomyosin ring participates in cytokinesis in almost all centripetally dividing eukaryotes, the majority of bacteria and archaea (except Crenarchaea) divide using a ring composed of the tubulin-related protein FtsZ. Curiously, despite molecular conservation of the division machinery components, division site placement and its cell cycle regulation occur by a variety of unrelated mechanisms even among organisms from the same kingdom. While molecular motors and cytoskeletal polymer dynamics contribute to force generation during eukaryotic cytokinesis, cytoskeletal polymer dynamics alone appears to be sufficient for force generation during prokaryotic cytokinesis. Intriguingly, there are life forms on this planet that appear to lack molecules currently known to participate in cytokinesis and how these cells perform cytokinesis remains a mystery waiting to be unravelled.
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Affiliation(s)
- Mohan K Balasubramanian
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604.
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Actin depolymerization drives actomyosin ring contraction during budding yeast cytokinesis. Dev Cell 2012; 22:1247-60. [PMID: 22698284 DOI: 10.1016/j.devcel.2012.04.015] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 01/27/2012] [Accepted: 04/19/2012] [Indexed: 01/21/2023]
Abstract
Actin filaments and myosin II are evolutionarily conserved force-generating components of the contractile ring during cytokinesis. Here we show that in budding yeast, actin filament depolymerization plays a major role in actomyosin ring constriction. Cofilin mutation or chemically stabilizing actin filaments attenuate actomyosin ring constriction. Deletion of myosin II motor domain or the myosin regulatory light chain reduced the contraction rate and also the rate of actin depolymerization in the ring. We constructed a quantitative microscopic model of actomyosin ring constriction via filament sliding driven by both actin depolymerization and myosin II motor activity. Model simulations based on experimental measurements support the notion that actin depolymerization is the predominant mechanism for ring constriction. The model predicts invariability of total contraction time regardless of the initial ring size, as originally reported for C. elegans embryonic cells. This prediction was validated in yeast cells of different sizes due to different ploidies.
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Salbreux G, Charras G, Paluch E. Actin cortex mechanics and cellular morphogenesis. Trends Cell Biol 2012; 22:536-45. [PMID: 22871642 DOI: 10.1016/j.tcb.2012.07.001] [Citation(s) in RCA: 514] [Impact Index Per Article: 42.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/27/2012] [Accepted: 07/04/2012] [Indexed: 12/11/2022]
Abstract
The cortex is a thin, crosslinked actin network lying immediately beneath the plasma membrane of animal cells. Myosin motors exert contractile forces in the meshwork. Because the cortex is attached to the cell membrane, it plays a central role in cell shape control. The proteic constituents of the cortex undergo rapid turnover, making the cortex both mechanically rigid and highly plastic, two properties essential to its function. The cortex has recently attracted increasing attention and its functions in cellular processes such as cytokinesis, cell migration, and embryogenesis are progressively being dissected. In this review, we summarize current knowledge on the structural organization, composition, and mechanics of the actin cortex, focusing on the link between molecular processes and macroscopic physical properties. We also highlight consequences of cortex dysfunction in disease.
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Affiliation(s)
- Guillaume Salbreux
- Max Planck Institute for the Physics of Complex Systems, Dresden, 01187, Germany.
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Functions of nonmuscle myosin II in assembly of the cellular contractile system. PLoS One 2012; 7:e40814. [PMID: 22808267 PMCID: PMC3396643 DOI: 10.1371/journal.pone.0040814] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 06/17/2012] [Indexed: 01/13/2023] Open
Abstract
The contractile system of nonmuscle cells consists of interconnected actomyosin networks and bundles anchored to focal adhesions. The initiation of the contractile system assembly is poorly understood structurally and mechanistically, whereas system's maturation heavily depends on nonmuscle myosin II (NMII). Using platinum replica electron microscopy in combination with fluorescence microscopy, we characterized the structural mechanisms of the contractile system assembly and roles of NMII at early stages of this process. We show that inhibition of NMII by a specific inhibitor, blebbistatin, in addition to known effects, such as disassembly of stress fibers and mature focal adhesions, also causes transformation of lamellipodia into unattached ruffles, loss of immature focal complexes, loss of cytoskeleton-associated NMII filaments and peripheral accumulation of activated, but unpolymerized NMII. After blebbistatin washout, assembly of the contractile system begins with quick and coordinated recovery of lamellipodia and focal complexes that occurs before reappearance of NMII bipolar filaments. The initial formation of focal complexes and subsequent assembly of NMII filaments preferentially occurred in association with filopodial bundles and concave actin bundles formed by filopodial roots at the lamellipodial base. Over time, accumulating NMII filaments help to transform the precursor structures, focal complexes and associated thin bundles, into stress fibers and mature focal adhesions. However, semi-sarcomeric organization of stress fibers develops at much slower rate. Together, our data suggest that activation of NMII motor activity by light chain phosphorylation occurs at the cell edge and is uncoupled from NMII assembly into bipolar filaments. We propose that activated, but unpolymerized NMII initiates focal complexes, thus providing traction for lamellipodial protrusion. Subsequently, the mechanical resistance of focal complexes activates a load-dependent mechanism of NMII polymerization in association with attached bundles, leading to assembly of stress fibers and maturation of focal adhesions.
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Dayraud C, Alié A, Jager M, Chang P, Le Guyader H, Manuel M, Quéinnec E. Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective. BMC Evol Biol 2012; 12:107. [PMID: 22747595 PMCID: PMC3502136 DOI: 10.1186/1471-2148-12-107] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 06/14/2012] [Indexed: 01/05/2023] Open
Abstract
Background Myosin II (or Myosin Heavy Chain II, MHCII) is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa) and striated muscle cells (MHCIIb). Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. Results We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa / MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa) has an expression pattern akin to that of "stem cell markers" (Piwi, Vasa…) and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. Conclusion MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2) has retained MHCIIa-like expression features furthermore suggests that muscular expression of the other paralogue, PpiMHCIIb1, was the result of neofunctionalisation within the ctenophore lineage, making independent origin of ctenophore muscle cells a likely option.
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Affiliation(s)
- Cyrielle Dayraud
- UMR 7138 CNRS MNHN IRD, Université Pierre et Marie Curie-Paris 6, Case 05, 4ème Étage, Bâtiment A, 7 quai St Bernard, Paris 75005, France
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