1
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Belyaev AV, Fedotova IV. Molecular mechanisms of catch bonds and their implications for platelet hemostasis. Biophys Rev 2023; 15:1233-1256. [PMID: 37974999 PMCID: PMC10643804 DOI: 10.1007/s12551-023-01144-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/07/2023] [Indexed: 11/19/2023] Open
Abstract
Adhesive molecular bonds between blood cells are essential for thrombosis and hemostasis as they provide means for platelet adhesion, aggregation, and signaling in flowing blood. According to the nowadays conventional definition, a "catch" bond is a type of non-covalent bio-molecular bridge, whose dissociation lifetime counter-intuitively increases with applied tensile force. Following recent experimental findings, such receptor-ligand protein bonds are vital to the blood cells involved in the prevention of bleeding (hemostatic response) and infection (immunity). In this review, we examine the up-to-date experimental discoveries and theoretical insights about catch bonds between the blood cells, their biomechanical principles at the molecular level, and their role in platelet thrombosis and hemostasis.
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Affiliation(s)
- Aleksey V. Belyaev
- Faculty of Physics, M.V.Lomonosov Moscow State University, 1, Leninskiye Gory, build.2, Moscow, 119991 Russia
| | - Irina V. Fedotova
- Faculty of Physics, M.V.Lomonosov Moscow State University, 1, Leninskiye Gory, build.2, Moscow, 119991 Russia
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2
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Alonso-Matilla R, Provenzano PP, Odde DJ. Optimal cell traction forces in a generalized motor-clutch model. Biophys J 2023; 122:3369-3385. [PMID: 37475213 PMCID: PMC10465728 DOI: 10.1016/j.bpj.2023.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/25/2023] [Accepted: 07/17/2023] [Indexed: 07/22/2023] Open
Abstract
Cells exert forces on mechanically compliant environments to sense stiffness, migrate, and remodel tissue. Cells can sense environmental stiffness via myosin-generated pulling forces acting on F-actin, which is in turn mechanically coupled to the environment via adhesive proteins, akin to a clutch in a drivetrain. In this "motor-clutch" framework, the force transmitted depends on the complex interplay of motor, clutch, and environmental properties. Previous mean-field analysis of the motor-clutch model identified the conditions for optimal stiffness for maximal force transmission via a dimensionless number that combines motor-clutch parameters. However, in this and other previous mean-field analyses, the motor-clutch system is assumed to have balanced motors and clutches and did not consider force-dependent clutch reinforcement and catch bond behavior. Here, we generalize the motor-clutch analytical framework to include imbalanced motor-clutch regimes, with clutch reinforcement and catch bonding, and investigate optimality with respect to all parameters. We found that traction force is strongly influenced by clutch stiffness, and we discovered an optimal clutch stiffness that maximizes traction force, suggesting that cells could tune their clutch mechanical properties to perform a specific function. The results provide guidance for maximizing the accuracy of cell-generated force measurements via molecular tension sensors by designing their mechanosensitive linker peptide to be as stiff as possible. In addition, we found that, on rigid substrates, the mean-field analysis identifies optimal motor properties, suggesting that cells could regulate their myosin repertoire and activity to maximize force transmission. Finally, we found that clutch reinforcement shifts the optimum substrate stiffness to larger values, whereas the optimum substrate stiffness is insensitive to clutch catch bond properties. Overall, our work reveals novel features of the motor-clutch model that can affect the design of molecular tension sensors and provide a generalized analytical framework for predicting and controlling cell adhesion and migration in immunotherapy and cancer.
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Affiliation(s)
- Roberto Alonso-Matilla
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota
| | - Paolo P Provenzano
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota; Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota; Department of Hematology, Oncology, and Transplantation, University of Minnesota, Minneapolis, Minnesota; Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - David J Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota; University of Minnesota Physical Sciences in Oncology Center, Minneapolis, Minnesota; University of Minnesota Center for Multiparametric Imaging of Tumor Immune Microenvironments, Minneapolis, Minnesota; Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
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3
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Venturini C, Sáez P. A multi-scale clutch model for adhesion complex mechanics. PLoS Comput Biol 2023; 19:e1011250. [PMID: 37450544 PMCID: PMC10393167 DOI: 10.1371/journal.pcbi.1011250] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/07/2023] [Indexed: 07/18/2023] Open
Abstract
Cell-matrix adhesion is a central mechanical function to a large number of phenomena in physiology and disease, including morphogenesis, wound healing, and tumor cell invasion. Today, how single cells respond to different extracellular cues has been comprehensively studied. However, how the mechanical behavior of the main individual molecules that form an adhesion complex cooperatively responds to force within the adhesion complex is still poorly understood. This is a key aspect of cell adhesion because how these cell adhesion molecules respond to force determines not only cell adhesion behavior but, ultimately, cell function. To answer this question, we develop a multi-scale computational model for adhesion complexes mechanics. We extend the classical clutch hypothesis to model individual adhesion chains made of a contractile actin network, a talin rod, and an integrin molecule that binds at individual adhesion sites on the extracellular matrix. We explore several scenarios of integrins dynamics and analyze the effects of diverse extracellular matrices on the behavior of the adhesion molecules and on the whole adhesion complex. Our results describe how every single component of the adhesion chain mechanically responds to the contractile actomyosin force and show how they control the traction forces exerted by the cell on the extracellular space. Importantly, our computational results agree with previous experimental data at the molecular and cellular levels. Our multi-scale clutch model presents a step forward not only to further understand adhesion complexes mechanics but also to impact, e.g., the engineering of biomimetic materials, tissue repairment, or strategies to arrest tumor progression.
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Affiliation(s)
- Chiara Venturini
- Laboratori de Càlcul Numèric (LaCaN), Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Pablo Sáez
- Laboratori de Càlcul Numèric (LaCaN), Universitat Politècnica de Catalunya, Barcelona, Spain
- E.T.S. de Ingeniería de Caminos, Universitat Politècnica de Catalunya, Barcelona, Spain
- Institut de Matemàtiques de la UPC-BarcelonaTech (IMTech), Universitat Politècnica de Catalunya, Barcelona, Spain
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4
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Stolarska MA, Rammohan AR. On the significance of membrane unfolding in mechanosensitive cell spreading: Its individual and synergistic effects. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2023; 20:2408-2438. [PMID: 36899540 DOI: 10.3934/mbe.2023113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Mechanosensitivity of cell spread area to substrate stiffness has been established both through experiments and different types of mathematical models of varying complexity including both the mechanics and biochemical reactions in the cell. What has not been addressed in previous mathematical models is the role of cell membrane dynamics on cell spreading, and an investigation of this issue is the goal of this work. We start with a simple mechanical model of cell spreading on a deformable substrate and progressively layer mechanisms to account for the traction dependent growth of focal adhesions, focal adhesion induced actin polymerization, membrane unfolding/exocytosis and contractility. This layering approach is intended to progressively help in understanding the role each mechanism plays in reproducing experimentally observed cell spread areas. To model membrane unfolding we introduce a novel approach based on defining an active rate of membrane deformation that is dependent on membrane tension. Our modeling approach allows us to show that tension-dependent membrane unfolding plays a critical role in achieving the large cell spread areas experimentally observed on stiff substrates. We also demonstrate that coupling between membrane unfolding and focal adhesion induced polymerization works synergistically to further enhance cell spread area sensitivity to substrate stiffness. This enhancement has to do with the fact that the peripheral velocity of spreading cells is associated with contributions from the different mechanisms by either enhancing the polymerization velocity at the leading edge or slowing down of the retrograde flow of actin within the cell. The temporal evolution of this balance in the model corresponds to the three-phase behavior observed experimentally during spreading. In the initial phase membrane unfolding is found to be particularly important.
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Affiliation(s)
- Magdalena A Stolarska
- Department of Mathematics, 2115 Summit Ave., University of St. Thomas, St. Paul, MN 55105, USA
| | - Aravind R Rammohan
- Corning Life Sciences, Corning Inc., 836 North St, Tewksbury, MA 01876, USA
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5
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Rizvi MS, Farutin A, Misbah C. Flow driven vesicle unbinding under mechanosensitive adhesion. SOFT MATTER 2022; 18:1209-1218. [PMID: 35040467 DOI: 10.1039/d1sm01284c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ligand receptor based adhesion is the primary mode of interaction of cellular blood constituents with the endothelium. These adhered entities also experience shear flow imposed by the blood which may lead to their detachment due to the viscous lift forces. Here, we have studied the role of the ligand-receptor bond kinetics in the detachment of an adhered vesicle (a simplified cell model) under shear flow. Using boundary integral formulation we performed numerical simulation of a two dimensional vesicle under shear flow for different values of applied shear rates and time scale of bond kinetics. We observe that the vesicle demonstrates three steady state configurations - adhered, pinned and detached for fast enough ligand-receptor kinetics (akin to Lennard-Jones adhesion). However, for slow bond kinetics the pinned state is not observed. We present scaling laws for the critical shear rates corresponding to the transitions among these three states. These results can help with identifying the processes of cell adhesion/detachment in the blood stream, prevalent features during the immune response and cancer metastasis.
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Affiliation(s)
- Mohd Suhail Rizvi
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502285, Telangana, India.
| | - Alexander Farutin
- Laboratoire Interdisciplinaire de Physique, Université Grenoble Alpes and CNRS, F-38000 Grenoble, France.
| | - Chaouqi Misbah
- Laboratoire Interdisciplinaire de Physique, Université Grenoble Alpes and CNRS, F-38000 Grenoble, France.
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6
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Chen Y, Ju LA. Biomechanical thrombosis: the dark side of force and dawn of mechano-medicine. Stroke Vasc Neurol 2020; 5:185-197. [PMID: 32606086 PMCID: PMC7337368 DOI: 10.1136/svn-2019-000302] [Citation(s) in RCA: 8] [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: 11/12/2019] [Accepted: 11/14/2019] [Indexed: 12/19/2022] Open
Abstract
Arterial thrombosis is in part contributed by excessive platelet aggregation, which can lead to blood clotting and subsequent heart attack and stroke. Platelets are sensitive to the haemodynamic environment. Rapid haemodynamcis and disturbed blood flow, which occur in vessels with growing thrombi and atherosclerotic plaques or is caused by medical device implantation and intervention, promotes platelet aggregation and thrombus formation. In such situations, conventional antiplatelet drugs often have suboptimal efficacy and a serious side effect of excessive bleeding. Investigating the mechanisms of platelet biomechanical activation provides insights distinct from the classic views of agonist-stimulated platelet thrombus formation. In this work, we review the recent discoveries underlying haemodynamic force-reinforced platelet binding and mechanosensing primarily mediated by three platelet receptors: glycoprotein Ib (GPIb), glycoprotein IIb/IIIa (GPIIb/IIIa) and glycoprotein VI (GPVI), and their implications for development of antithrombotic 'mechano-medicine' .
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Affiliation(s)
- Yunfeng Chen
- Molecular Medicine, Scripps Research Institute, La Jolla, California, USA
| | - Lining Arnold Ju
- School of Biomedical Engineering, Heart Research Institute and Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
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7
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Asaro RJ, Lin K, Zhu Q. Mechanosensitivity Occurs along the Adhesome's Force Train and Affects Traction Stress. Biophys J 2019; 117:1599-1614. [PMID: 31604520 DOI: 10.1016/j.bpj.2019.08.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/29/2019] [Accepted: 08/28/2019] [Indexed: 11/16/2022] Open
Abstract
Herein, we consider the process of force development along the adhesome within cell focal adhesions. Our model adhesome consists of the actin cytoskeleton-vinculin-talin-integrin-ligand-extracellular matrix-substrate force train. We specifically consider the effects of substrate stiffness on the force levels expected along the train and on the traction stresses they create at the substrate. We find that significant effects of substrate stiffness are manifest within each constitutive component of the force train and on the density and distribution of integrin/ligand anchorage points with the substrate. By following each component of the force train, we are able to delineate specific gaps in the quantitative descriptions of bond survival that must be addressed so that improved quantitative forecasts become possible. Our analysis provides, however, a rational description for the various levels of traction stresses that have been reported and of the effect of substrate stiffness. Our approach has the advantage of being quite clear as to how each constituent contributes to the net development of force and traction stress. We demonstrate that to provide truly quantitative forecasts for traction stress, a far more detailed description of integrin/ligand density and distribution is required. Although integrin density is already a well-recognized important feature of adhesion, our analysis places a finer point on it in the manner of how we evaluate the magnitude of traction stress. We provide mechanistic insight into how understanding of this vital element of the adhesion process may proceed by addressing mechanistic causes of integrin clustering that may lead to patterning.
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Affiliation(s)
- Robert J Asaro
- Structural Engineering, Department of Structural Engineering, University of California San Diego, San Diego, California.
| | - Kuanpo Lin
- Structural Engineering, Department of Structural Engineering, University of California San Diego, San Diego, California
| | - Qiang Zhu
- Structural Engineering, Department of Structural Engineering, University of California San Diego, San Diego, California
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8
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Numerical Simulation of a Multiscale Cell Motility Model Based on the Kinetic Theory of Active Particles. Symmetry (Basel) 2019. [DOI: 10.3390/sym11081003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this work, we deal with a kinetic model of cell movement that takes into consideration the structure of the extracellular matrix, considering cell membrane reactions, haptotaxis, and chemotaxis, which plays a key role in a number of biological processes such as wound healing and tumor cell invasion. The modeling is performed at a microscopic scale, and then, a scaling limit is performed to derive the macroscopic model. We run some selected numerical experiments aimed at understanding cell movement and adhesion under certain documented situations, and we measure the alignment of the cells and compare it with the pathways determined by the extracellular matrix by introducing new alignment operators.
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9
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Chen Y, Ju LA, Zhou F, Liao J, Xue L, Su QP, Jin D, Yuan Y, Lu H, Jackson SP, Zhu C. An integrin α IIbβ 3 intermediate affinity state mediates biomechanical platelet aggregation. NATURE MATERIALS 2019; 18:760-769. [PMID: 30911119 PMCID: PMC6586518 DOI: 10.1038/s41563-019-0323-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 02/19/2019] [Indexed: 05/20/2023]
Abstract
Integrins are membrane receptors that mediate cell adhesion and mechanosensing. The structure-function relationship of integrins remains incompletely understood, despite the extensive studies carried out because of its importance to basic cell biology and translational medicine. Using a fluorescence dual biomembrane force probe, microfluidics and cone-and-plate rheometry, we applied precisely controlled mechanical stimulations to platelets and identified an intermediate state of integrin αIIbβ3 that is characterized by an ectodomain conformation, ligand affinity and bond lifetimes that are all intermediate between the well-known inactive and active states. This intermediate state is induced by ligand engagement of glycoprotein (GP) Ibα via a mechanosignalling pathway and potentiates the outside-in mechanosignalling of αIIbβ3 for further transition to the active state during integrin mechanical affinity maturation. Our work reveals distinct αIIbβ3 state transitions in response to biomechanical and biochemical stimuli, and identifies a role for the αIIbβ3 intermediate state in promoting biomechanical platelet aggregation.
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Affiliation(s)
- Yunfeng Chen
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lining Arnold Ju
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Camperdown, New South Wales, Australia
| | - Fangyuan Zhou
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jiexi Liao
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lingzhou Xue
- Department of Statistics, Pennsylvania State University, University Park, PA, USA
| | - Qian Peter Su
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Dayong Jin
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Yuping Yuan
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Shaun P Jackson
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA, USA.
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.
- Charles Perkins Centre, The University of Sydney, Camperdown, New South Wales, Australia.
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering and Georgia Institute of Technology, Atlanta, GA, USA.
- Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, USA.
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
- Heart Research Institute, The University of Sydney, Camperdown, New South Wales, Australia.
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10
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Yeoman BM, Katira P. A stochastic algorithm for accurately predicting path persistence of cells migrating in 3D matrix environments. PLoS One 2018; 13:e0207216. [PMID: 30440015 PMCID: PMC6237354 DOI: 10.1371/journal.pone.0207216] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 10/26/2018] [Indexed: 01/07/2023] Open
Abstract
Cell mobility plays a critical role in immune response, wound healing, and the rate of cancer metastasis and tumor progression. Mobility within a three-dimensional (3D) matrix environment can be characterized by the average velocity of cell migration and the persistence length of the path it follows. Computational models that aim to predict cell migration within such 3D environments need to be able predict both of these properties as a function of the various cellular and extra-cellular factors that influence the migration process. A large number of models have been developed to predict the velocity of cell migration driven by cellular protrusions in 3D environments. However, prediction of the persistence of a cell's path is a more tedious matter, as it requires simulating cells for a long time while they migrate through the model extra-cellular matrix (ECM). This can be a computationally expensive process, and only recently have there been attempts to quantify cell persistence as a function of key cellular or matrix properties. Here, we propose a new stochastic algorithm that can simulate and analyze 3D cell migration occurring over days with a computation time of minutes, opening new possibilities of testing and predicting long-term cell migration behavior as a function of a large variety of cell and matrix properties. In this model, the matrix elements are generated as needed and stochastically based on the biophysical and biochemical properties of the ECM the cell migrates through. This approach significantly reduces the computational resources required to track and calculate cell matrix interactions. Using this algorithm, we predict the effect of various cellular and matrix properties such as cell polarity, cell mechanoactivity, matrix fiber density, matrix stiffness, fiber alignment, and fiber binding site density on path persistence of cellular migration and the mean squared displacement of cells over long periods of time.
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Affiliation(s)
- Benjamin Michael Yeoman
- Mechanical Engineering Department, San Diego State University, San Diego, CA, United States of America
- Department of Bioengineering, University of California San Diego, San Diego, CA, United States of America
| | - Parag Katira
- Mechanical Engineering Department, San Diego State University, San Diego, CA, United States of America
- Computational Science Research Center, San Diego State University, San Diego, CA, United States of America
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11
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Regulatory element in fibrin triggers tension-activated transition from catch to slip bonds. Proc Natl Acad Sci U S A 2018; 115:8575-8580. [PMID: 30087181 DOI: 10.1073/pnas.1802576115] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fibrin formation and mechanical stability are essential in thrombosis and hemostasis. To reveal how mechanical load impacts fibrin, we carried out optical trap-based single-molecule forced unbinding experiments. The strength of noncovalent A:a knob-hole bond stabilizing fibrin polymers first increases with tensile force (catch bonds) and then decreases with force when the force exceeds a critical value (slip bonds). To provide the structural basis of catch-slip-bond behavior, we analyzed crystal structures and performed molecular modeling of A:a knob-hole complex. The movable flap (residues γ295 to γ305) containing the weak calcium-binding site γ2 serves as a tension sensor. Flap dissociation from the B domain in the γ-nodule and translocation to knob 'A' triggers hole 'a' closure, resulting in the increase of binding affinity and prolonged bond lifetimes. The discovery of biphasic kinetics of knob-hole bond rupture is quantitatively explained by using a theory, formulated in terms of structural transitions in the binding pocket between the low-affinity (slip) and high-affinity (catch) states. We provide a general framework to understand the mechanical response of protein pairs capable of tension-induced remodeling of their association interface. Strengthening of the A:a knob-hole bonds at 30- to 40-pN forces might favor formation of nascent fibrin clots subject to hydrodynamic shear in vivo.
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12
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Abstract
Tissues are viscoelastic in nature and their physical properties play a fundamental role in development, tumorigenesis, and wound healing. Cell response to matrix elasticity is well understood through a “molecular clutch” which engages when stiffness is sufficiently high to expose binding sites in mechanosensitive proteins. Here we show that cell response to pure viscous surfaces (i.e., with no elastic component) can be explained through the same molecular clutch. Mechanisms used by cells to sense rigidity are more universal and can be used to unveil cell interaction with complex viscoelastic environments. The research presents a tool to understand cells within tissues and in turn opens new avenues to incorporate viscosity into the design of synthetic cellular microenvironments. Cell response to matrix rigidity has been explained by the mechanical properties of the actin-talin-integrin-fibronectin clutch. Here the molecular clutch model is extended to account for cell interactions with purely viscous surfaces (i.e., without an elastic component). Supported lipid bilayers present an idealized and controllable system through which to study this concept. Using lipids of different diffusion coefficients, the mobility (i.e., surface viscosity) of the presented ligands (in this case RGD) was altered by an order of magnitude. Cell size and cytoskeletal organization were proportional to viscosity. Furthermore, there was a higher number of focal adhesions and a higher phosphorylation of FAK on less-mobile (more-viscous) surfaces. Actin retrograde flow, an indicator of the force exerted on surfaces, was also seen to be faster on more mobile surfaces. This has consequential effects on downstream molecules; the mechanosensitive YAP protein localized to the nucleus more on less-mobile (more-viscous) surfaces and differentiation of myoblast cells was enhanced on higher viscosity. This behavior was explained within the framework of the molecular clutch model, with lower viscosity leading to a low force loading rate, preventing the exposure of mechanosensitive proteins, and with a higher viscosity causing a higher force loading rate exposing these sites, activating downstream pathways. Consequently, the understanding of how viscosity (regardless of matrix stiffness) influences cell response adds a further tool to engineer materials that control cell behavior.
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13
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Oria R, Wiegand T, Escribano J, Elosegui-Artola A, Uriarte JJ, Moreno-Pulido C, Platzman I, Delcanale P, Albertazzi L, Navajas D, Trepat X, García-Aznar JM, Cavalcanti-Adam EA, Roca-Cusachs P. Force loading explains spatial sensing of ligands by cells. Nature 2017; 552:219-224. [PMID: 29211717 DOI: 10.1038/nature24662] [Citation(s) in RCA: 195] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 10/13/2017] [Indexed: 12/12/2022]
Abstract
Cells can sense the density and distribution of extracellular matrix (ECM) molecules by means of individual integrin proteins and larger, integrin-containing adhesion complexes within the cell membrane. This spatial sensing drives cellular activity in a variety of normal and pathological contexts. Previous studies of cells on rigid glass surfaces have shown that spatial sensing of ECM ligands takes place at the nanometre scale, with integrin clustering and subsequent formation of focal adhesions impaired when single integrin-ligand bonds are separated by more than a few tens of nanometres. It has thus been suggested that a crosslinking 'adaptor' protein of this size might connect integrins to the actin cytoskeleton, acting as a molecular ruler that senses ligand spacing directly. Here, we develop gels whose rigidity and nanometre-scale distribution of ECM ligands can be controlled and altered. We find that increasing the spacing between ligands promotes the growth of focal adhesions on low-rigidity substrates, but leads to adhesion collapse on more-rigid substrates. Furthermore, disordering the ligand distribution drastically increases adhesion growth, but reduces the rigidity threshold for adhesion collapse. The growth and collapse of focal adhesions are mirrored by, respectively, the nuclear or cytosolic localization of the transcriptional regulator protein YAP. We explain these findings not through direct sensing of ligand spacing, but by using an expanded computational molecular-clutch model, in which individual integrin-ECM bonds-the molecular clutches-respond to force loading by recruiting extra integrins, up to a maximum value. This generates more clutches, redistributing the overall force among them, and reducing the force loading per clutch. At high rigidity and high ligand spacing, maximum recruitment is reached, preventing further force redistribution and leading to adhesion collapse. Measurements of cellular traction forces and actin flow speeds support our model. Our results provide a general framework for how cells sense spatial and physical information at the nanoscale, precisely tuning the range of conditions at which they form adhesions and activate transcriptional regulation.
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Affiliation(s)
- Roger Oria
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain
| | - Tina Wiegand
- Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany.,Heidelberg University, D-69120 Heidelberg, Germany
| | - Jorge Escribano
- Aragon Institute of Engineering Research (I3A), University of Zaragoza, 50018 Zaragoza, Spain
| | - Alberto Elosegui-Artola
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | | | - Cristian Moreno-Pulido
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | - Ilia Platzman
- Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany.,Heidelberg University, D-69120 Heidelberg, Germany
| | - Pietro Delcanale
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | - Lorenzo Albertazzi
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | - Daniel Navajas
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain.,Centro de Investigación Biomédica en Red en Enfermedades Respiratorias, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain.,Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina, 08028 Barcelona, Spain
| | | | - Elisabetta Ada Cavalcanti-Adam
- Max Planck Institute for Medical Research, D-69120 Heidelberg, Germany.,Heidelberg University, D-69120 Heidelberg, Germany
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain
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14
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Nevzorova TA, Zhao Q, Lomakin YA, Ponomareva AA, Mukhitov AR, Purohit PK, Weisel JW, Litvinov RI. Single-Molecule Interactions of a Monoclonal Anti-DNA Antibody with DNA. BIONANOSCIENCE 2017; 7:132-147. [PMID: 29104846 DOI: 10.1007/s12668-016-0303-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Interactions of DNA with proteins are essential for key biological processes and have both a fundamental and practical significance. In particular, DNA binding to anti-DNA antibodies is a pathogenic mechanism in autoimmune pathology, such as systemic lupus erythematosus. Here we measured at the single-molecule level binding and forced unbinding of surface-attached DNA and a monoclonal anti-DNA antibody MRL4 from a lupus erythematosus mouse. In optical trap-based force spectroscopy, a microscopic antibodycoated latex bead is trapped by a focused laser beam and repeatedly brought into contact with a DNA-coated surface. After careful discrimination of non-specific interactions, we showed that the DNA-antibody rupture force spectra had two regimes, reflecting formation of weaker (20-40 pN) and stronger (>40 pN) immune complexes that implies the existence of at least two bound states with different mechanical stability. The two-dimensional force-free off-rate for the DNA-antibody complexes was ~2.2 × 10-3 s-1, the transition state distance was ~0.94 nm, the apparent on-rate was ~5.26 s-1, and the stiffness of the DNA-antibody complex was characterized by a spring constant of 0.0021 pN/nm, suggesting that the DNA-antibody complex is a relatively stable, but soft and deformable macromolecular structure. The stretching elasticity of the DNA molecules was characteristic of single-stranded DNA, suggesting preferential binding of the MRL4 antibody to one strand of DNA. Collectively, the results provide fundamental characteristics of formation and forced dissociation of DNA-antibody complexes that help to understand principles of DNA-protein interactions and shed light on the molecular basis of autoimmune diseases accompanied by formation of anti-DNA antibodies.
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Affiliation(s)
- Tatiana A Nevzorova
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA.,Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlyovskaya St, Kazan 420008, Russian Federation
| | - Qingze Zhao
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania School of Engineering and Applied Science, 220 S. 33rd Street, Philadelphia, PA 19104, USA
| | - Yakov A Lomakin
- Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Mikluho-Maklaya St, Moscow 117997, Russian Federation
| | - Anastasia A Ponomareva
- Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlyovskaya St, Kazan 420008, Russian Federation.,Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, 2/31 Lobachevsky str, Kazan 420111, Russian Federation
| | - Alexander R Mukhitov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Prashant K Purohit
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania School of Engineering and Applied Science, 220 S. 33rd Street, Philadelphia, PA 19104, USA
| | - John W Weisel
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, 421 Curie Boulevard, Philadelphia, PA 19104, USA.,Institute of Fundamental Medicine and Biology, Kazan Federal University, 18 Kremlyovskaya St, Kazan 420008, Russian Federation
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15
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Höök P, Litvinov RI, Kim OV, Xu S, Xu Z, Bennett JS, Alber MS, Weisel JW. Strong Binding of Platelet Integrin αIIbβ3 to Fibrin Clots: Potential Target to Destabilize Thrombi. Sci Rep 2017; 7:13001. [PMID: 29021578 PMCID: PMC5636895 DOI: 10.1038/s41598-017-12615-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/07/2017] [Indexed: 01/17/2023] Open
Abstract
The formation of platelet thrombi is determined by the integrin αIIbβ3-mediated interactions of platelets with fibrinogen and fibrin. Blood clotting in vivo is catalyzed by thrombin, which simultaneously induces fibrinogen binding to αIIbβ3 and converts fibrinogen to fibrin. Thus, after a short time, thrombus formation is governed by αIIbβ3 binding to fibrin fibers. Surprisingly, there is little understanding of αIIbβ3 interaction with fibrin polymers. Here we used an optical trap-based system to measure the binding of single αIIbβ3 molecules to polymeric fibrin and compare it to αIIbβ3 binding to monomeric fibrin and fibrinogen. Like αIIbβ3 binding to fibrinogen and monomeric fibrin, we found that αIIbβ3 binding to polymeric fibrin can be segregated into two binding regimes, one with weaker rupture forces of 30-60 pN and a second with stronger rupture forces >60 pN that peaked at 70-80 pN. However, we found that the mechanical stability of the bimolecular αIIbβ3-ligand complexes had the following order: fibrin polymer > fibrin monomer > fibrinogen. These quantitative differences reflect the distinct specificity and underlying molecular mechanisms of αIIbβ3-mediated reactions, implying that targeting platelet interactions with fibrin could increase the therapeutic indices of antithrombotic agents by focusing on the destabilization of thrombi rather than the prevention of platelet aggregation.
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Affiliation(s)
- Peter Höök
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN, USA
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.,Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Oleg V Kim
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.,Department of Mathematics, University of California, Riverside, Riverside, CA, USA
| | - Shixin Xu
- Department of Mathematics, University of California, Riverside, Riverside, CA, USA
| | - Zhiliang Xu
- Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, IN, USA
| | - Joel S Bennett
- Department of Medicine, Hematology-Oncology Division, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Mark S Alber
- Department of Mathematics, University of California, Riverside, Riverside, CA, USA.,Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John W Weisel
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
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16
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Kononova O, Litvinov RI, Blokhin DS, Klochkov VV, Weisel JW, Bennett JS, Barsegov V. Mechanistic Basis for the Binding of RGD- and AGDV-Peptides to the Platelet Integrin αIIbβ3. Biochemistry 2017; 56:1932-1942. [PMID: 28277676 DOI: 10.1021/acs.biochem.6b01113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Binding of soluble fibrinogen to the activated conformation of the integrin αIIbβ3 is required for platelet aggregation and is mediated exclusively by the C-terminal AGDV-containing dodecapeptide (γC-12) sequence of the fibrinogen γ chain. However, peptides containing the Arg-Gly-Asp (RGD) sequences located in two places in the fibrinogen Aα chain inhibit soluble fibrinogen binding to αIIbβ3 and make substantial contributions to αIIbβ3 binding when fibrinogen is immobilized and when it is converted to fibrin. Here, we employed optical trap-based nanomechanical measurements and computational molecular modeling to determine the kinetics, energetics, and structural details of cyclic RGDFK (cRGDFK) and γC-12 binding to αIIbβ3. Docking analysis revealed that NMR-determined solution structures of cRGDFK and γC-12 bind to both the open and closed αIIbβ3 conformers at the interface between the αIIb β-propeller domain and the β3 βI domain. The nanomechanical measurements revealed that cRGDFK binds to αIIbβ3 at least as tightly as γC-12. A subsequent analysis of molecular force profiles and the number of peptide-αIIbβ3 binding contacts revealed that both peptides form stable bimolecular complexes with αIIbβ3 that dissociate in the 60-120 pN range. The Gibbs free energy profiles of the αIIbβ3-peptide complexes revealed that the overall stability of the αIIbβ3-cRGDFK complex was comparable with that of the αIIbβ3-γC-12 complex. Thus, these results provide a mechanistic explanation for previous observations that RGD- and AGDV-containing peptides are both potent inhibitors of the αIIbβ3-fibrinogen interactions and are consistent with the observation that RGD motifs, in addition to AGDV, support interaction of αIIbβ3 with immobilized fibrinogen and fibrin.
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Affiliation(s)
- Olga Kononova
- Department of Chemistry, University of Massachusetts , Lowell, Massachusetts 01854, United States.,Moscow Institute of Physics and Technology , Moscow Region 141700, Russian Federation
| | | | | | | | | | | | - Valeri Barsegov
- Department of Chemistry, University of Massachusetts , Lowell, Massachusetts 01854, United States.,Moscow Institute of Physics and Technology , Moscow Region 141700, Russian Federation
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17
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A Rough Energy Landscape to Describe Surface-Linked Antibody and Antigen Bond Formation. Sci Rep 2016; 6:35193. [PMID: 27731375 PMCID: PMC5059681 DOI: 10.1038/srep35193] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 09/27/2016] [Indexed: 11/08/2022] Open
Abstract
Antibodies and B cell receptors often bind their antigen at cell-cell interface while both molecular species are surface-bound, which impacts bond kinetics and function. Despite the description of complex energy landscapes for dissociation kinetics which may also result in significantly different association kinetics, surface-bound molecule (2D) association kinetics usually remain described by an on-rate due to crossing of a single free energy barrier, and few experimental works have measured association kinetics under conditions implying force and two-dimensional relative ligand-receptor motion. We use a new laminar flow chamber to measure 2D bond formation with systematic variation of the distribution of encounter durations between antigen and antibody, in a range from 0.1 to 10 ms. Under physiologically relevant forces, 2D association is 100-fold slower than 3D association as studied by surface plasmon resonance assays. Supported by brownian dynamics simulations, our results show that a minimal encounter duration is required for 2D association; an energy landscape featuring a rough initial part might be a reasonable way of accounting for this. By systematically varying the temperature of our experiments, we evaluate roughness at 2kBT, in the range of previously proposed rough parts of landscapes models during dissociation.
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18
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Abstract
We have developed a technique to directly quantify cell-substrate adhesion force using micropipette aspiration. The micropipette is positioned perpendicular to the surface of an adherent cell and a constant-rate aspiration pressure is applied. Since the micropipette diameter and the aspiration pressure are our control parameters, we have direct knowledge of the aspiration force, whereas the cell behavior is monitored either in brightfield or interference reflection microscopy. This setup thus allows us to explore a range of geometric parameters, such as projected cell area, adhesion area, or pipette size, as well as dynamical parameters such as the loading rate. We find that cell detachment is a well-defined event occurring at a critical aspiration pressure, and that the detachment force scales with the cell adhesion area (for a given micropipette diameter and loading rate), which defines a critical stress. Taking into account the cell adhesion area, intrinsic parameters of the adhesion bonds, and the loading rate, a minimal model provides an expression for the critical stress that helps rationalize our experimental results.
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19
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Litvinov RI, Farrell DH, Weisel JW, Bennett JS. The Platelet Integrin αIIbβ3 Differentially Interacts with Fibrin Versus Fibrinogen. J Biol Chem 2016; 291:7858-67. [PMID: 26867579 DOI: 10.1074/jbc.m115.706861] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Indexed: 01/05/2023] Open
Abstract
Fibrinogen binding to the integrin αIIbβ3 mediates platelet aggregation and spreading on fibrinogen-coated surfaces. However,in vivoαIIbβ3 activation and fibrinogen conversion to fibrin occur simultaneously, although the relative contributions of fibrinogenversusfibrin to αIIbβ3-mediated platelet functions are unknown. Here, we compared the interaction of αIIbβ3 with fibrin and fibrinogen to explore their differential effects. A microscopic bead coated with fibrinogen or monomeric fibrin produced by treating the immobilized fibrinogen with thrombin was captured by a laser beam and repeatedly brought into contact with surface-attached purified αIIbβ3. When αIIbβ3-ligand complexes were detected, the rupture forces were measured and displayed as force histograms. Monomeric fibrin displayed a higher probability of interacting with αIIbβ3 and a greater binding strength. αIIbβ3-fibrin interactions were also less sensitive to inhibition by abciximab and eptifibatide. Both fibrinogen- and fibrin-αIIbβ3 interactions were partially inhibited by RGD peptides, suggesting the existence of common RGD-containing binding motifs. This assumption was supported using the fibrin variants αD97E or αD574E with mutated RGD motifs. Fibrin made from a fibrinogen γ'/γ' variant lacking the γC αIIbβ3-binding motif was more reactive with αIIbβ3 than the parent fibrinogen. These results demonstrate that fibrin is more reactive with αIIbβ3 than fibrinogen. Fibrin is also less sensitive to αIIbβ3 inhibitors, suggesting that fibrin and fibrinogen have distinct binding requirements. In particular, the maintenance of αIIbβ3 binding activity in the absence of the γC-dodecapeptide and the α-chain RGD sequences suggests that the αIIbβ3-binding sites in fibrin are not confined to its known γ-chain and RGD motifs.
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Affiliation(s)
- Rustem I Litvinov
- From the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6060 and
| | - David H Farrell
- the Oregon Health and Science University, Portland, Oregon 97239
| | - John W Weisel
- From the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6060 and
| | - Joel S Bennett
- From the University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104-6060 and
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20
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Platelets and physics: How platelets “feel” and respond to their mechanical microenvironment. Blood Rev 2015; 29:377-86. [DOI: 10.1016/j.blre.2015.05.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 05/04/2015] [Accepted: 05/04/2015] [Indexed: 01/08/2023]
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21
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Both platelet- and endothelial cell-derived ERp5 support thrombus formation in a laser-induced mouse model of thrombosis. Blood 2015; 125:2276-85. [PMID: 25624318 DOI: 10.1182/blood-2013-12-547208] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 01/14/2015] [Indexed: 01/08/2023] Open
Abstract
Protein disulfide isomerase (PDI) and endoplasmic reticulum protein 57 (ERp57) are emerging as important regulators of thrombus formation. Another thiol isomerase, endoplasmic reticulum protein 5 (ERp5), is involved in platelet activation. We show here the involvement of ERp5 in thrombus formation using the mouse laser-injury model of thrombosis and a specific antibody raised against recombinant ERp5. Anti-ERp5 antibody inhibited ERp5-dependent platelet and endothelial cell disulfide reductase activity in vitro. ERp5 release at the thrombus site was detected after infusion of Alexa Fluor 488-labeled anti-ERp5 antibody at 0.05 μg/g body weight, a dose that does not inhibit thrombus formation. Anti-ERp5 at 3 μg/g body weight inhibited laser-induced thrombus formation in vivo by causing a 70% decrease in the deposition of platelets and a 62% decrease in fibrin accumulation compared to infusion of control antibody (P < .01). ERp5 binds to β3 integrin with an equilibrium dissociation constant (KD) of 21 µM, measured by surface plasmon resonance. The cysteine residues in the ERp5 active sites are not required for binding to β3 integrin. These results provide evidence for a novel role of ERp5 in thrombus formation, a function that may be mediated through its association with αIIbβ3.
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22
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Abstract
Intravascular blood clots form in an environment in which hydrodynamic forces dominate and in which fluid-mediated transport is the primary means of moving material. The clotting system has evolved to exploit fluid dynamic mechanisms and to overcome fluid dynamic challenges to ensure that clots that preserve vascular integrity can form over the wide range of flow conditions found in the circulation. Fluid-mediated interactions between the many large deformable red blood cells and the few small rigid platelets lead to high platelet concentrations near vessel walls where platelets contribute to clotting. Receptor-ligand pairs with diverse kinetic and mechanical characteristics work synergistically to arrest rapidly flowing cells on an injured vessel. Variations in hydrodynamic stresses switch on and off the function of key clotting polymers. Protein transport to, from, and within a developing clot determines whether and how fast it grows. We review ongoing experimental and modeling research to understand these and related phenomena.
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Affiliation(s)
- Aaron L. Fogelson
- Departments of Mathematics and Bioengineering, University of Utah, Salt Lake City, Utah 84112
| | - Keith B. Neeves
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401
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23
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Moriarty R, McManus CA, Lambert M, Tilley T, Devocelle M, Brennan M, Kerrigan SW, Cox D. A novel role for the fibrinogen Asn-Gly-Arg (NGR) motif in platelet function. Thromb Haemost 2014; 113:290-304. [PMID: 25413489 DOI: 10.1160/th14-04-0366] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 09/12/2014] [Indexed: 01/20/2023]
Abstract
The integrin αIIbβ3 on resting platelets can bind to immobilised fibrinogen resulting in platelet spreading and activation but requires activation to bind to soluble fibrinogen. αIIbβ3 is known to interact with the general integrin-recognition motif RGD (arginine-glycine-aspartate) as well as the fibrinogen-specific γ-chain dodecapeptide; however, it is not known how fibrinogen binding triggers platelet activation. NGR (asparagine-glycine-arginine) is another integrin-recognition sequence present in fibrinogen and this study aims to determine if it plays a role in the interaction between fibrinogen and αIIbβ3. NGR-containing peptides inhibited resting platelet adhesion to fibrinogen with an IC50 of 175 µM but failed to inhibit the adhesion of activated platelets to fibrinogen (IC50> 500 µM). Resting platelet adhesion to mutant fibrinogens lacking the NGR sequences was reduced compared to normal fibrinogen under both static and shear conditions (200 s⁻¹). However, pre-activated platelets were able to fully spread on all types of fibrinogen. Thus, the NGR motif in fibrinogen is the site that is primarily responsible for the interaction with resting αIIbβ3 and is responsible for triggering platelet activation.
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Affiliation(s)
| | | | | | | | | | | | | | - Dermot Cox
- Dermot Cox, BSc, PhD, Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, 123 St. Stephens Green, Dublin 2, Ireland, Tel.: +35 3 1 402 2152, Fax: +35 3 1 402 2453, E-mail:
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24
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Rakshit S, Sivasankar S. Biomechanics of cell adhesion: how force regulates the lifetime of adhesive bonds at the single molecule level. Phys Chem Chem Phys 2014; 16:2211-23. [PMID: 24419646 DOI: 10.1039/c3cp53963f] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cell adhesion proteins play critical roles in positioning cells during development, segregating cells into distinct tissue compartments and in maintaining tissue integrity. The principle function of these proteins is to bind cells together and resist mechanical force. Adhesive proteins also enable migrating cells to adhere and roll on surfaces even in the presence of shear forces exerted by fluid flow. Recently, several experimental and theoretical studies have provided quantitative insights into the physical mechanisms by which adhesion proteins modulate their unbinding kinetics in response to tensile force. This perspective reviews these biophysical investigations. We focus on single molecule studies of cadherins, selectins, integrins, the von Willebrand factor and FimH adhesion proteins; the effect of mechanical force on the lifetime of these interactions has been extensively characterized. We review both theoretical models and experimental investigations and discuss future directions in this exciting area of research.
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Affiliation(s)
- Sabyasachi Rakshit
- Department of Physics and Astronomy, Iowa State University, Ames, IA 50011, USA.
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25
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Herman P, El-Kirat-Chatel S, Beaussart A, Geoghegan JA, Foster TJ, Dufrêne YF. The binding force of the staphylococcal adhesin SdrG is remarkably strong. Mol Microbiol 2014; 93:356-68. [PMID: 24898289 DOI: 10.1111/mmi.12663] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2014] [Indexed: 11/27/2022]
Abstract
SdrG is a cell surface adhesin from Staphylococcus epidermidis which binds to the blood plasma protein fibrinogen (Fg). Ligand binding follows a 'dock, lock and latch' model involving dynamic conformational changes of the adhesin that result in a greatly stabilized adhesin-ligand complex. To date, the force and dynamics of this multistep interaction are poorly understood. Here we use atomic force microscopy (AFM) to unravel the binding strength and cell surface localization of SdrG at molecular resolution. Single-cell force spectroscopy shows that SdrG mediates time-dependent attachment to Fg-coated surfaces. Single-molecule force spectroscopy with Fg-coated AFM tips demonstrates that the adhesin forms nanoscale domains on the cell surface, which we believe contribute to strengthen cell adhesion. Notably, we find that the rupture force of single SdrG-Fg bonds is very large, ∼ 2 nN, equivalent to the strength of a covalent bond, and shows a low dissociation rate, suggesting that the bond is very stable. The strong binding force, slow dissociation and clustering of SdrG provide a molecular foundation for the ability of S. epidermidis to colonize implanted biomaterials and to withstand physiological shear forces.
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Affiliation(s)
- Philippe Herman
- Université catholique de Louvain, Institute of Life Sciences, Croix du Sud, 1, bte L7.04.01., B-1348, Louvain-la-Neuve, Belgium
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26
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Elosegui-Artola A, Bazellières E, Allen MD, Andreu I, Oria R, Sunyer R, Gomm JJ, Marshall JF, Jones JL, Trepat X, Roca-Cusachs P. Rigidity sensing and adaptation through regulation of integrin types. NATURE MATERIALS 2014; 13:631-7. [PMID: 24793358 PMCID: PMC4031069 DOI: 10.1038/nmat3960] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 03/27/2014] [Indexed: 05/13/2023]
Abstract
Tissue rigidity regulates processes in development, cancer and wound healing. However, how cells detect rigidity, and thereby modulate their behaviour, remains unknown. Here, we show that sensing and adaptation to matrix rigidity in breast myoepithelial cells is determined by the bond dynamics of different integrin types. Cell binding to fibronectin through either α5β1 integrins (constitutively expressed) or αvβ6 integrins (selectively expressed in cancer and development) adapts force generation, actin flow and integrin recruitment to rigidities associated with healthy or malignant tissue, respectively. In vitro experiments and theoretical modelling further demonstrate that this behaviour is explained by the different binding and unbinding rates of both integrin types to fibronectin. Moreover, rigidity sensing through differences in integrin bond dynamics applies both when integrins bind separately and when they compete for binding to fibronectin.
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Affiliation(s)
- Alberto Elosegui-Artola
- Centre for Tumour Biology Barts Cancer Institute - a Cancer Research UK Centre of Excellence. Queen Mary, University of London, London, UK
- Institute for Bioengineering of Catalonia, Barcelona, Spain
| | | | - Michael D. Allen
- Centre for Tumour Biology Barts Cancer Institute - a Cancer Research UK Centre of Excellence. Queen Mary, University of London, London, UK
| | - Ion Andreu
- CEIT and TECNUN (University of Navarra). Donostia-San Sebastian, Spain
| | - Roger Oria
- Institute for Bioengineering of Catalonia, Barcelona, Spain
| | - Raimon Sunyer
- Institute for Bioengineering of Catalonia, Barcelona, Spain
| | - Jennifer J. Gomm
- Centre for Tumour Biology Barts Cancer Institute - a Cancer Research UK Centre of Excellence. Queen Mary, University of London, London, UK
| | - John F. Marshall
- Centre for Tumour Biology Barts Cancer Institute - a Cancer Research UK Centre of Excellence. Queen Mary, University of London, London, UK
| | - J. Louise Jones
- Centre for Tumour Biology Barts Cancer Institute - a Cancer Research UK Centre of Excellence. Queen Mary, University of London, London, UK
| | - Xavier Trepat
- Institute for Bioengineering of Catalonia, Barcelona, Spain
- University of Barcelona, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Authors for correspondence: Pere Roca-Cusachs, PhD, Assistant professor, Institute for Bioengineering of Catalonia / University of Barcelona, C/ Baldiri i Reixac, 15-21, 08028, Barcelona Spain, Tel: (+34) 934 020 863, ; Xavier Trepat, PhD, ICREA Research Professor, Institute for Bioengineering of Catalonia, C/ Baldiri i Reixac, 15-21, 08028, Barcelona Spain, Tel: (+34) 934 020 265,
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia, Barcelona, Spain
- University of Barcelona, Barcelona, Spain
- Authors for correspondence: Pere Roca-Cusachs, PhD, Assistant professor, Institute for Bioengineering of Catalonia / University of Barcelona, C/ Baldiri i Reixac, 15-21, 08028, Barcelona Spain, Tel: (+34) 934 020 863, ; Xavier Trepat, PhD, ICREA Research Professor, Institute for Bioengineering of Catalonia, C/ Baldiri i Reixac, 15-21, 08028, Barcelona Spain, Tel: (+34) 934 020 265,
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27
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Abstract
T cells are key players of the mammalian adaptive immune system. They experience different mechanical microenvironments during their life cycle, from the thymus, secondary lymph organs, and peripheral tissues that are free of externally applied force, but display variable substrate rigidities to the blood and lymphatic circulation systems, where complicated hydrodynamic forces are present. Regardless of whether T cells are subject to external forces or generate their own internal forces, they respond and adapt to different biomechanical cues to modulate their adhesion, migration, trafficking, and triggering of immune functions through mechanical regulation of various molecules that bear force. These include adhesive receptors, immunoreceptors, motor proteins, cytoskeletal proteins, and their associated molecules. Here, we discuss the forces acting on various surface and cytoplasmic proteins of a T cell in different mechanical milieus. We review existing data on how force regulates protein conformational changes and interactions with counter molecules, including integrins, actin, and the T-cell receptor, and how each relates to T-cell functions.
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Affiliation(s)
- Wei Chen
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
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28
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Adamson K, Dolan C, Moran N, Forster RJ, Keyes TE. RGD Labeled Ru(II) Polypyridyl Conjugates for Platelet Integrin αIIbβ3 Recognition and as Reporters of Integrin Conformation. Bioconjug Chem 2014; 25:928-44. [DOI: 10.1021/bc5000737] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kellie Adamson
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Ciaran Dolan
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Niamh Moran
- The
Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Robert J. Forster
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Tia E. Keyes
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
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29
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Kononova O, Jones L, Barsegov V. Order statistics inference for describing topological coupling and mechanical symmetry breaking in multidomain proteins. J Chem Phys 2014; 139:121913. [PMID: 24089725 DOI: 10.1063/1.4816104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cooperativity is a hallmark of proteins, many of which show a modular architecture comprising discrete structural domains. Detecting and describing dynamic couplings between structural regions is difficult in view of the many-body nature of protein-protein interactions. By utilizing the GPU-based computational acceleration, we carried out simulations of the protein forced unfolding for the dimer WW - WW of the all-β-sheet WW domains used as a model multidomain protein. We found that while the physically non-interacting identical protein domains (WW) show nearly symmetric mechanical properties at low tension, reflected, e.g., in the similarity of their distributions of unfolding times, these properties become distinctly different when tension is increased. Moreover, the uncorrelated unfolding transitions at a low pulling force become increasingly more correlated (dependent) at higher forces. Hence, the applied force not only breaks "the mechanical symmetry" but also couples the physically non-interacting protein domains forming a multi-domain protein. We call this effect "the topological coupling." We developed a new theory, inspired by order statistics, to characterize protein-protein interactions in multi-domain proteins. The method utilizes the squared-Gaussian model, but it can also be used in conjunction with other parametric models for the distribution of unfolding times. The formalism can be taken to the single-molecule experimental lab to probe mechanical cooperativity and domain communication in multi-domain proteins.
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Affiliation(s)
- Olga Kononova
- Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, USA
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30
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Adamson K, Spain E, Prendergast U, Forster RJ, Moran N, Keyes TE. Ligand capture and activation of human platelets at monolayer modified gold surfaces. Biomater Sci 2014; 2:1509-1520. [DOI: 10.1039/c4bm00241e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The effect of RGD peptides, alkane and PEG in self assembled mixed monolayers on gold on platelet adhesion and activation is explored.
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Affiliation(s)
- Kellie Adamson
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
- Department of Molecular and Cellular Therapeutics
- Royal College of Surgeons in Ireland
| | - Elaine Spain
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
| | - Una Prendergast
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
| | | | - Niamh Moran
- Department of Molecular and Cellular Therapeutics
- Royal College of Surgeons in Ireland
- Dublin 2, Ireland
| | - Tia E. Keyes
- School of Chemical Sciences
- Dublin City University
- Dublin 9, Ireland
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31
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Litvinov RI, Yarovoi SV, Rauova L, Barsegov V, Sachais BS, Rux AH, Hinds JL, Arepally GM, Cines DB, Weisel JW. Distinct specificity and single-molecule kinetics characterize the interaction of pathogenic and non-pathogenic antibodies against platelet factor 4-heparin complexes with platelet factor 4. J Biol Chem 2013; 288:33060-70. [PMID: 24097975 DOI: 10.1074/jbc.m113.481598] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Heparin-induced thrombocytopenia (HIT) is a thrombotic complication of heparin therapy mediated by antibodies to complexes between platelet factor 4 (PF4) and heparin or cellular glycosaminoglycans. However, only a fraction of patients with anti-PF4-heparin antibodies develop HIT, implying that only a subset of these antibodies is pathogenic. The basis for the pathogenic potential of anti-PF4-heparin antibodies remains unclear. To elucidate the intrinsic PF4-binding properties of HIT-like monoclonal antibody (KKO) versus non-pathogenic antibody (RTO) at the single-molecule level, we utilized optical trap-based force spectroscopy to measure the strength and probability of binding of surface-attached antibodies with oligomeric PF4 to simulate interactions on cells. To mimic the effect of heparin in bringing PF4 complexes into proximity, we chemically cross-linked PF4 tetramers using glutaraldehyde. Analysis of the force histograms revealed that KKO-PF4 interactions had ∼10-fold faster on-rates than RTO-PF4, and apparent equilibrium dissociation constants differed ∼10-fold with similar force-free off-rates (k(off) = 0.0031 and 0.0029 s(-1)). Qualitatively similar results were obtained for KKO and RTO interacting with PF4-heparin complexes. In contrast to WT PF4, KKO and RTO showed lower and similar binding probabilities to cross-linked PF4(K50E), which forms few if any oligomers. Thus, formation of stable PF4 polymers results in much stronger interactions with the pathogenic antibody without a significant effect on the binding of the non-pathogenic antibody. These results suggest a fundamental difference in the antigen-binding mechanisms between model pathogenic and non-pathogenic anti-PF4 antibodies that might underlie their distinct pathophysiological behaviors.
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Epitope mapping for monoclonal antibody reveals the activation mechanism for αVβ3 integrin. PLoS One 2013; 8:e66096. [PMID: 23840404 PMCID: PMC3688720 DOI: 10.1371/journal.pone.0066096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 05/02/2013] [Indexed: 12/02/2022] Open
Abstract
Epitopes for a panel of anti-αVβ3 monoclonal antibodies (mAbs) were investigated to explore the activation mechanism of αVβ3 integrin. Experiments utilizing αV/αIIb domain-swapping chimeras revealed that among the nine mAbs tested, five recognized the ligand-binding β-propeller domain and four recognized the thigh domain, which is the upper leg of the αV chain. Interestingly, the four mAbs included function-blocking as well as non-functional mAbs, although they bound at a distance from the ligand-binding site. The epitopes for these four mAbs were further determined using human-to-mouse αV chimeras. Among the four, P3G8 recognized an amino acid residue, Ser-528, located on the side of the thigh domain, while AMF-7, M9, and P2W7 all recognized a common epitope, Ser-462, that was located close to the α-genu, where integrin makes a sharp bend in the crystal structure. Fibrinogen binding studies for cells expressing wild-type αVβ3 confirmed that AMF-7, M9, and P2W7 were inhibitory, while P3G8 was non-functional. However, these mAbs were all unable to block binding when αVβ3 was constrained in its extended conformation. These results suggest that AMF-7, M9, and P2W7 block ligand binding allosterically by stabilizing the angle of the bend in the bent conformation. Thus, a switchblade-like movement of the integrin leg is indispensable for the affinity regulation of αVβ3 integrin.
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