1
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Liu H, Welburn JPI. A circle of life: platelet and megakaryocyte cytoskeleton dynamics in health and disease. Open Biol 2024; 14:240041. [PMID: 38835242 DOI: 10.1098/rsob.240041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/24/2024] [Indexed: 06/06/2024] Open
Abstract
Platelets are blood cells derived from megakaryocytes that play a central role in regulating haemostasis and vascular integrity. The microtubule cytoskeleton of megakaryocytes undergoes a critical dynamic reorganization during cycles of endomitosis and platelet biogenesis. Quiescent platelets have a discoid shape maintained by a marginal band composed of microtubule bundles, which undergoes remarkable remodelling during platelet activation, driving shape change and platelet function. Disrupting or enhancing this process can cause platelet dysfunction such as bleeding disorders or thrombosis. However, little is known about the molecular mechanisms underlying the reorganization of the cytoskeleton in the platelet lineage. Recent studies indicate that the emergence of a unique platelet tubulin code and specific pathogenic tubulin mutations cause platelet defects and bleeding disorders. Frequently, these mutations exhibit dominant negative effects, offering valuable insights into both platelet disease mechanisms and the functioning of tubulins. This review will highlight our current understanding of the role of the microtubule cytoskeleton in the life and death of platelets, along with its relevance to platelet disorders.
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Affiliation(s)
- Haonan Liu
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Julie P I Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
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2
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Severin S, Consonni A, Chicanne G, Allart S, Payrastre B, Gratacap MP. SHIP1 Controls Internal Platelet Contraction and α IIbβ 3 Integrin Dynamics in Early Platelet Activation. Int J Mol Sci 2023; 24:ijms24020958. [PMID: 36674478 PMCID: PMC9860818 DOI: 10.3390/ijms24020958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 01/06/2023] Open
Abstract
The Src homology 2 domain-containing inositol 5-phosphatase 1 (SHIP1) is known to dephosphorylate PtdIns(3,4,5)P3 into PtdIns(3,4)P2 and to interact with several signaling proteins though its docking functions. It has been shown to negatively regulate platelet adhesion and spreading on a fibrinogen surface and to positively regulate thrombus growth. In the present study, we have investigated its role during the early phase of platelet activation. Using confocal-based morphometric analysis, we found that SHIP1 is involved in the regulation of cytoskeletal organization and internal contractile activity in thrombin-activated platelets. The absence of SHIP1 has no significant impact on thrombin-induced Akt or Erk1/2 activation, but it selectively affects the RhoA/Rho-kinase pathway and myosin IIA relocalization to the cytoskeleton. SHIP1 interacts with the spectrin-based membrane skeleton, and its absence induces a loss of sustained association of integrins to this network together with a decrease in αIIbβ3 integrin clustering following thrombin stimulation. This αIIbβ3 integrin dynamics requires the contractile cytoskeleton under the control of SHIP1. RhoA activation, internal platelet contraction, and membrane skeleton integrin association were insensitive to the inhibition of PtdIns(3,4,5)P3 synthesis or SHIP1 phosphatase activity, indicating a role for the docking properties of SHIP1 in these processes. Altogether, our data reveal a lipid-independent function for SHIP1 in the regulation of the contractile cytoskeleton and integrin dynamics in platelets.
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Affiliation(s)
- Sonia Severin
- Institut des Maladies Métabolique et Cardiovasculaire (I2MC), Inserm and Université Toulouse III Paul-Sabatier (UMR-1297), 1 Avenue J. Poulhes, CEDEX 4, 31432 Toulouse, France
- Correspondence: (S.S.); (M.-P.G.); Tel.: +33-5-31-22-41-43 (S.S.); +33-5-31-22-41-50 (M.-P.G.)
| | - Alessandra Consonni
- Institut des Maladies Métabolique et Cardiovasculaire (I2MC), Inserm and Université Toulouse III Paul-Sabatier (UMR-1297), 1 Avenue J. Poulhes, CEDEX 4, 31432 Toulouse, France
- Laboratory of Biochemistry, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy
| | - Gaëtan Chicanne
- Institut des Maladies Métabolique et Cardiovasculaire (I2MC), Inserm and Université Toulouse III Paul-Sabatier (UMR-1297), 1 Avenue J. Poulhes, CEDEX 4, 31432 Toulouse, France
| | - Sophie Allart
- Institut Toulousain des Maladies Infectieuses et Inflammatoires (Infinity), Université Toulouse III Paul-Sabatier and Inserm (UMR-1291) and CNRS (UMR-5051), Centre Hospitalier Universitaire Purpan, CEDEX 3, 31024 Toulouse, France
| | - Bernard Payrastre
- Institut des Maladies Métabolique et Cardiovasculaire (I2MC), Inserm and Université Toulouse III Paul-Sabatier (UMR-1297), 1 Avenue J. Poulhes, CEDEX 4, 31432 Toulouse, France
- Laboratoire d’Hématologie, Centre de Référence des Pathologies Plaquettaires, Centre Hospitalier Universitaire Rangueil, CEDEX 4, 31432 Toulouse, France
| | - Marie-Pierre Gratacap
- Institut des Maladies Métabolique et Cardiovasculaire (I2MC), Inserm and Université Toulouse III Paul-Sabatier (UMR-1297), 1 Avenue J. Poulhes, CEDEX 4, 31432 Toulouse, France
- Correspondence: (S.S.); (M.-P.G.); Tel.: +33-5-31-22-41-43 (S.S.); +33-5-31-22-41-50 (M.-P.G.)
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3
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Bura A, de Matteis MA, Bender M, Swinkels M, Versluis J, Jansen AJG, Jurak Begonja A. Oculocerebrorenal syndrome of Lowe protein controls cytoskeletal reorganisation during human platelet spreading. Br J Haematol 2023; 200:87-99. [PMID: 36176266 DOI: 10.1111/bjh.18478] [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: 05/10/2022] [Revised: 09/05/2022] [Accepted: 09/14/2022] [Indexed: 11/28/2022]
Abstract
Lowe syndrome (LS) is a rare, X-linked disorder characterised by numerous symptoms affecting the brain, the eyes, and the kidneys. It is caused by mutations in the oculocerebrorenal syndrome of Lowe (OCRL) protein, a 5-phosphatase localised in different cellular compartments that dephosphorylates phosphatidylinositol-4,5-bisphosphate into phosphatidylinositol-4-monophosphate. Some patients with LS also have bleeding disorders, with normal to low platelet (PLT) count and impaired PLT function. However, the mechanism of PLT dysfunction in patients with LS is not completely understood. The main function of PLTs is to activate upon vessel wall injury and stop the bleeding by clot formation. PLT activation is accompanied by a shape change that is a result of massive cytoskeletal rearrangements. Here, we show that OCRL-inhibited human PLTs do not fully spread, form mostly filopodia, and accumulate actin nodules. These nodules co-localise with ARP2/3 subunit p34, vinculin, and sorting nexin 9. Furthermore, OCRL-inhibited PLTs have a retained microtubular coil with high levels of acetylated tubulin. Also, myosin light chain phosphorylation is decreased upon OCRL inhibition, without impaired degranulation or integrin activation. Taken together, these results suggest that OCRL contributes to cytoskeletal rearrangements during PLT activation that could explain mild bleeding problems in patients with LS.
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Affiliation(s)
- Ana Bura
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Maria Antonietta de Matteis
- Telethon Institute of Genetics and Medicine, TIGEM, Pozzuoli, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Markus Bender
- Institute of Experimental Biomedicine, University Hospital Wuerzburg, Rudolf Virchow Center, Wuerzburg, Germany
| | - Maurice Swinkels
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jurjen Versluis
- Erasmus MC University Medical Center, Rotterdam, the Netherlands
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4
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A predictive multiscale model for simulating flow-induced platelet activation: Correlating in silico results with in vitro results. J Biomech 2021; 117:110275. [PMID: 33529943 DOI: 10.1016/j.jbiomech.2021.110275] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 01/16/2021] [Indexed: 11/21/2022]
Abstract
Flow-induced platelet activation prompts complex filopodial formation. Continuum methods fail to capture such molecular-scale mechanisms. A multiscale numerical model was developed to simulate this activation process, where a Dissipative Particle Dynamics (DPD) model of viscous blood flow is interfaced with a Coarse Grained Molecular Dynamics (CGMD) platelet model. Embedded in DPD blood flow, the macroscopic dynamic stresses are interactively transferred to the CGMD model, inducing intra-platelet associated events. The platelets activate by a biomechanical transductive linkage chain and dynamically change their shape in response. The models are fully coupled via a hybrid-potential interface and multiple time-stepping (MTS) schemes for handling the disparity between the spatiotemporal scales. Cumulative hemodynamic stresses that may lead to platelet activation are mapped on the surface membrane and simultaneously transmitted to the cytoplasm and cytoskeleton. Upon activation, the flowing platelets lose their quiescent discoid shape and evolve by forming filopodia. The model predictions were validated by a set of in vitro experiments, Platelets were exposed to various combinations of shear stresses and durations in our programmable hemodynamic shearing device (HSD). Their shape change was measured at multiple time points using scanning electron microscopy (SEM). The CGMD model parameters were fine-tuned by interrogating a parameter space established in these experiments. Segmentation of the SEM imaging streams was conducted by a deep machine learning system. This model can be further employed to simulate shear mediated platelet activation thrombosis initiation and to study the effects of modulating platelet properties to enhance their shear resistance via mechanotransduction pathways.
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5
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Sadoul K, Lafanechère L, Grichine A. Live imaging of single platelets at work. Platelets 2020; 31:551-558. [PMID: 31880193 DOI: 10.1080/09537104.2019.1708886] [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: 10/25/2022]
Abstract
Although live imaging of dynamic processes in platelets is a challenging task, several important observations have been published during the last 20 years. We will discuss the amazing insights that have been achieved, the difficulties that can be encountered as well as some questions still open and the future technical perspectives.
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Affiliation(s)
- Karin Sadoul
- Institute for Advanced Biosciences, University Grenoble Alpes , Grenoble, France
| | - Laurence Lafanechère
- Institute for Advanced Biosciences, University Grenoble Alpes , Grenoble, France
| | - Alexei Grichine
- Institute for Advanced Biosciences, University Grenoble Alpes , Grenoble, France
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6
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Riley DRJ, Khalil JS, Naseem KM, Rivero F. Biochemical and immunocytochemical characterization of coronins in platelets. Platelets 2019; 31:913-924. [PMID: 31801396 PMCID: PMC7497283 DOI: 10.1080/09537104.2019.1696457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Rapid reorganization of the actin cytoskeleton in response to receptor-mediated signaling cascades allows platelets to transition from a discoid shape to a flat spread shape upon adhesion to damaged vessel walls. Coronins are conserved regulators of the actin cytoskeleton turnover but they also participate in signaling events. To gain a better picture of their functions in platelets we have undertaken a biochemical and immunocytochemical investigation with a focus on Coro1. We found that class I coronins Coro1, 2 and 3 are abundant in human and mouse platelets whereas little Coro7 can be detected. Coro1 is mainly cytosolic, but a significant amount associates with membranes in an actin-independent manner and does not translocate from or to the membrane fraction upon exposure to thrombin, collagen or prostacyclin. Coro1 rapidly translocates to the Triton insoluble cytoskeleton upon platelet stimulation with thrombin or collagen. Coro1, 2 and 3 show a diffuse cytoplasmic localization with discontinuous accumulation at the cell cortex and actin nodules of human platelets, where all three coronins colocalize. Our data are consistent with a role of coronins as integrators of extracellular signals with actin remodeling and suggests a high extent of functional overlap among class I coronins in platelets.
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Affiliation(s)
- David R J Riley
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
| | - Jawad S Khalil
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK.,School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol , Bristol, UK
| | - Khalid M Naseem
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds , Leeds, UK
| | - Francisco Rivero
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
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7
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8
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Variants in exons 5 and 6 of ACTB cause syndromic thrombocytopenia. Nat Commun 2018; 9:4250. [PMID: 30315159 PMCID: PMC6185941 DOI: 10.1038/s41467-018-06713-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 09/20/2018] [Indexed: 01/08/2023] Open
Abstract
Germline mutations in the ubiquitously expressed ACTB, which encodes β-cytoplasmic actin (CYA), are almost exclusively associated with Baraitser-Winter Cerebrofrontofacial syndrome (BWCFF). Here, we report six patients with previously undescribed heterozygous variants clustered in the 3′-coding region of ACTB. Patients present with clinical features distinct from BWCFF, including mild developmental disability, microcephaly, and thrombocytopenia with platelet anisotropy. Using patient-derived fibroblasts, we demonstrate cohort specific changes to β-CYA filament populations, which include the enhanced recruitment of thrombocytopenia-associated actin binding proteins (ABPs). These perturbed interactions are supported by in silico modeling and are validated in disease-relevant thrombocytes. Co-examination of actin and microtubule cytoskeleton constituents in patient-derived megakaryocytes and thrombocytes indicates that these β-CYA mutations inhibit the final stages of platelet maturation by compromising microtubule organization. Our results define an ACTB-associated clinical syndrome with a distinct genotype-phenotype correlation and delineate molecular mechanisms underlying thrombocytopenia in this patient cohort. Genetic variants in ACTB and ACTG1 have been associated with Baraitser-Winter Cerebrofrontofacial syndrome. Here, the authors report of a syndromic thrombocytopenia caused by variants in ACTB exons 5 or 6 that compromise the organization and coupling of the cytoskeleton, leading to impaired platelet maturation.
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9
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Seifert J, Rheinlaender J, Lang F, Gawaz M, Schäffer TE. Thrombin-induced cytoskeleton dynamics in spread human platelets observed with fast scanning ion conductance microscopy. Sci Rep 2017; 7:4810. [PMID: 28684746 PMCID: PMC5500533 DOI: 10.1038/s41598-017-04999-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 05/19/2017] [Indexed: 02/08/2023] Open
Abstract
Platelets are small anucleate blood cells involved in haemostasis. Platelet activation, caused by agonists such as thrombin or by contact with the extracellular matrix, leads to platelet adhesion, aggregation, and coagulation. Activated platelets undergo shape changes, adhere, and spread at the site of injury to form a blood clot. We investigated the morphology and morphological dynamics of human platelets after complete spreading using fast scanning ion conductance microscopy (SICM). In contrast to unstimulated platelets, thrombin-stimulated platelets showed increased morphological activity after spreading and exhibited dynamic morphological changes in the form of wave-like movements of the lamellipodium and dynamic protrusions on the platelet body. The increase in morphological activity was dependent on thrombin concentration. No increase in activity was observed following exposure to other activation agonists or during contact-induced activation. Inhibition of actin polymerization and inhibition of dynein significantly decreased the activity of thrombin-stimulated platelets. Our data suggest that these morphological dynamics after spreading are thrombin-specific and might play a role in coagulation and blood clot formation.
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Affiliation(s)
- Jan Seifert
- Institute of Applied Physics, University of Tübingen, Tübingen, Germany
| | | | - Florian Lang
- Department of Physiology, University of Tübingen, Tübingen, Germany
| | - Meinrad Gawaz
- Department of Cardiology and Cardiovascular Diseases, University of Tübingen, Tübingen, Germany
| | - Tilman E Schäffer
- Institute of Applied Physics, University of Tübingen, Tübingen, Germany.
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10
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Ngo ATP, Thierheimer MLD, Babur Ö, Rocheleau AD, Huang T, Pang J, Rigg RA, Mitrugno A, Theodorescu D, Burchard J, Nan X, Demir E, McCarty OJT, Aslan JE. Assessment of roles for the Rho-specific guanine nucleotide dissociation inhibitor Ly-GDI in platelet function: a spatial systems approach. Am J Physiol Cell Physiol 2017; 312:C527-C536. [PMID: 28148498 PMCID: PMC5407014 DOI: 10.1152/ajpcell.00274.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 01/25/2017] [Accepted: 01/25/2017] [Indexed: 12/29/2022]
Abstract
On activation at sites of vascular injury, platelets undergo morphological alterations essential to hemostasis via cytoskeletal reorganizations driven by the Rho GTPases Rac1, Cdc42, and RhoA. Here we investigate roles for Rho-specific guanine nucleotide dissociation inhibitor proteins (RhoGDIs) in platelet function. We find that platelets express two RhoGDI family members, RhoGDI and Ly-GDI. Whereas RhoGDI localizes throughout platelets in a granule-like manner, Ly-GDI shows an asymmetric, polarized localization that largely overlaps with Rac1 and Cdc42 as well as microtubules and protein kinase C (PKC) in platelets adherent to fibrinogen. Antibody interference and platelet spreading experiments suggest a specific role for Ly-GDI in platelet function. Intracellular signaling studies based on interactome and pathways analyses also support a regulatory role for Ly-GDI, which is phosphorylated at PKC substrate motifs in a PKC-dependent manner in response to the platelet collagen receptor glycoprotein (GP) VI-specific agonist collagen-related peptide. Additionally, PKC inhibition diffuses the polarized organization of Ly-GDI in spread platelets relative to its colocalization with Rac1 and Cdc42. Together, our results suggest a role for Ly-GDI in the localized regulation of Rho GTPases in platelets and hypothesize a link between the PKC and Rho GTPase signaling systems in platelet function.
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Affiliation(s)
- Anh T P Ngo
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Marisa L D Thierheimer
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon.,School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, Oregon; and
| | - Özgün Babur
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon.,Computational Biology Program, Oregon Health & Science University, Portland, Oregon
| | - Anne D Rocheleau
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Tao Huang
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Jiaqing Pang
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Rachel A Rigg
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Annachiara Mitrugno
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Dan Theodorescu
- Department of Surgery, Department of Pharmacology, and Comprehensive Cancer Center University of Colorado, Aurora, Colorado
| | - Julja Burchard
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon
| | - Xiaolin Nan
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon
| | - Emek Demir
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon.,Computational Biology Program, Oregon Health & Science University, Portland, Oregon
| | - Owen J T McCarty
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, Oregon.,Department of Cell, Developmental & Cancer Biology, Oregon Health & Science University, Portland, Oregon.,Division of Hematology & Medical Oncology, Oregon Health & Science University, Portland, Oregon
| | - Joseph E Aslan
- Knight Cardiovascular Institute, School of Medicine, Oregon Health & Science University, Portland, Oregon;
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11
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Todinova S, Komsa-Penkova R, Krumova S, Taneva SG, Golemanov G, Georgieva G, Tonchev P, Tsankov B, Beshev L, Balashev K, Andreeva TD. PlA2 Polymorphism in Glycoprotein IIb/IIIa Modulates the Morphology and Nanomechanics of Platelets. Clin Appl Thromb Hemost 2017; 23:951-960. [PMID: 28081621 DOI: 10.1177/1076029616687847] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Glycoprotein IIb/IIIa (GPIIb/IIIa) is the most abundant platelet surface receptor for fibrinogen and von Willebrand factor. Polymorphism PlA1/A2 in the gene of GPIIb/IIIa is among the risk factors for the development of arterial and venous thrombosis. The aim of this study is to evaluate the effect of the carriage of PlA1/A2 on the size, topographic features, and membrane stiffness of platelets from healthy controls and patients with deep venous thrombosis (DVT). Atomic force microscopy (AFM) imaging and nanoindentation (force-distance curves) were applied to investigate the morphological and nanomechanical properties (Young's modulus) of platelets immobilized on glass surface. The surface roughness ( Ra) and height ( h) of platelets from patients with DVT, carriers of mutant allele PlA2 ( Ra = 30.2 ± 6 nm; h = 766 ± 182 nm) and noncarriers ( Ra = 28.6 ± 6 nm; h = 865 ± 290 nm), were lower than those of healthy carriers of allele PlA2 ( Ra = 48.1 ± 12 nm; h = 1072 ± 338 nm) and healthy noncarriers ( Ra = 49.7 ± 14 nm; h = 1021 ± 433 nm), respectively. Platelets isolated from patients with DVT, both carriers and noncarriers, exhibit much higher degree of stiffness at the stage of spreading ( E = 327 ± 85 kPa and 341 ± 102 kPa, respectively) compared to healthy noncarriers ( E = 198 ± 50 kPa). In addition, more pronounced level of platelet activation was found in polymorphism carriers. In conclusion, the carriage of PlA2 allele modulates the activation state, morphology, and membrane elasticity of platelets.
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Affiliation(s)
- Svetla Todinova
- 1 Department of Biomacromolecules and Biomolecular Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | | | - Sashka Krumova
- 1 Department of Biomacromolecules and Biomolecular Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Stefka G Taneva
- 1 Department of Biomacromolecules and Biomolecular Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Georgy Golemanov
- 2 Department of Biochemistry, Medical University, Pleven, Bulgaria
| | - Galia Georgieva
- 2 Department of Biochemistry, Medical University, Pleven, Bulgaria
| | - Pencho Tonchev
- 3 Department of Surgery, University Hospital, Pleven, Bulgaria
| | - Boris Tsankov
- 3 Department of Surgery, University Hospital, Pleven, Bulgaria
| | - Lyubomir Beshev
- 3 Department of Surgery, University Hospital, Pleven, Bulgaria
| | - Konstantin Balashev
- 4 Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, Sofia University, Sofia, Bulgaria
| | - Tonya D Andreeva
- 1 Department of Biomacromolecules and Biomolecular Interactions, Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
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12
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Valéra MC, Parant O, Cenac C, Arnaud C, Gallini A, Hamdi S, Sié P, Arnal JF, Payrastre B. Platelet Adhesion and Thrombus Formation in Whole Blood at Arterial Shear Rate at the End of Pregnancy. Am J Reprod Immunol 2015; 74:533-41. [PMID: 26435170 DOI: 10.1111/aji.12433] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 09/09/2015] [Indexed: 11/28/2022] Open
Abstract
PROBLEM Platelet reactivity has not been evaluated in integrated functional testing during normal pregnancy. Here, we analysed platelet functions under arterial shear rate in comparison with static conditions. METHOD OF STUDY Thirty pregnant women with uncomplicated pregnancies and 30 healthy non-pregnant women were enrolled in this study. Platelet adhesion to collagen and fibrinogen and subsequent thrombus formation were measured at arterial shear rate in whole blood using a microfluidic and imaging system. Standard light transmission aggregometry, flow cytometry of activation markers in washed platelets and impedance aggregometry in whole blood were also used to assess platelet responsiveness in static conditions. RESULTS Compared to non-pregnant controls, thrombus formation on collagen fibres and firm platelet adhesion on fibrinogen under arterial shear rate were significantly reduced in pregnant women. Platelet aggregometry assays in suspension showed a slight increase in platelet reactivity in pregnant women. CONCLUSION While platelet aggregometry and platelet activation markers in static conditions show little changes in platelet reactivity, monitoring of platelet adhesion and thrombus growth on collagen or fibrinogen under flow condition in whole blood indicates a significant decrease in pregnant women compared to controls. This decrease might contribute to counteract a hypercoagulable state and to reduce the risk of arterial thrombosis.
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Affiliation(s)
- Marie-Cécile Valéra
- INSERM, U1048, CHU de Toulouse and Université Toulouse 3, Toulouse Cedex 04, France
| | - Olivier Parant
- Service de Gynécologie Obstétrique, CHU de Toulouse, Toulouse, France
| | - Claire Cenac
- INSERM, U1043, CNRS, U5282 and Université Toulouse 3, CPTP, Toulouse, France
| | - Catherine Arnaud
- INSERM, U1027 and Université Toulouse 3, Toulouse, France.,Unité de soutien méthodologique à la recherche clinique, service d'épidémiologie, CHU de Toulouse, Toulouse, France
| | - Adeline Gallini
- INSERM, U1027 and Université Toulouse 3, Toulouse, France.,Unité de soutien méthodologique à la recherche clinique, service d'épidémiologie, CHU de Toulouse, Toulouse, France
| | - Safouane Hamdi
- Laboratoire de Biochimie and Groupe de Recherche en Fertilité Humaine, EA 3694, CHU de Toulouse, Toulouse, France
| | - Pierre Sié
- INSERM, U1048, CHU de Toulouse and Université Toulouse 3, Toulouse Cedex 04, France.,Laboratoire d'Hématologie, CHU de Toulouse, Toulouse Cedex 04, France
| | - Jean-François Arnal
- INSERM, U1048, CHU de Toulouse and Université Toulouse 3, Toulouse Cedex 04, France
| | - Bernard Payrastre
- INSERM, U1048, CHU de Toulouse and Université Toulouse 3, Toulouse Cedex 04, France.,Laboratoire d'Hématologie, CHU de Toulouse, Toulouse Cedex 04, France
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13
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Essential role of class II PI3K-C2α in platelet membrane morphology. Blood 2015; 126:1128-37. [DOI: 10.1182/blood-2015-03-636670] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/15/2015] [Indexed: 11/20/2022] Open
Abstract
Key Points
PI3K-C2α controls platelet membrane structure and remodeling. PI3K-C2α is a key regulator of a basal housekeeping PI3P pool in platelets.
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14
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Sadoul K. New explanations for old observations: marginal band coiling during platelet activation. J Thromb Haemost 2015; 13:333-46. [PMID: 25510620 DOI: 10.1111/jth.12819] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 12/07/2014] [Indexed: 11/26/2022]
Abstract
Blood platelets are tiny cell fragments derived from megakaryocytes. Their primary function is to control blood vessel integrity and ensure hemostasis if a vessel wall is damaged. Circulating quiescent platelets have a flat, discoid shape maintained by a circumferential microtubule bundle, called the marginal band (MB). In the case of injury platelets are activated and rapidly adopt a spherical shape due to microtubule motor-induced elongation and subsequent coiling of the MB. Platelet activation and shape change can be transient or become irreversible. This depends on the strength of the activation stimulus, which is translated into a cytoskeletal crosstalk between microtubules, their motors and the actomyosin cortex, ensuring stimulus-response coupling. Following microtubule motor-driven disc-to-sphere transition, a strong stimulus will lead to compression of the sphere through actomyosin cortex contraction. This will concentrate the granules in the center of the platelet and accelerate their exocytosis. Once granules are released, platelets have crossed the point of no return to irreversible activation. This review summarizes the current knowledge of the molecular mechanism leading to platelet shape change, with a special emphasis on microtubules, and refers to previously published observations, which have been essential for generating an integrated view of cytoskeletal rearrangements during platelet activation.
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Affiliation(s)
- K Sadoul
- University Grenoble Alpes, IAB, Grenoble, France; INSERM, IAB, Grenoble, France; CHU de Grenoble, IAB, Grenoble, France
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15
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Finkenstaedt-Quinn SA, Ge S, Haynes CL. Cytoskeleton dynamics in drug-treated platelets. Anal Bioanal Chem 2015; 407:2803-9. [PMID: 25701419 DOI: 10.1007/s00216-015-8523-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 01/25/2015] [Accepted: 01/27/2015] [Indexed: 12/15/2022]
Abstract
Platelet activation is a key process in blood clot formation. During activation, platelets go through both chemical and physical changes, including secretion of chemical messengers and cellular shape change. Platelet shape change is mediated by the two major cytoskeletal elements in platelets, the actin matrix and microtubule ring. Most studies to date have evaluated these structures qualitatively, whereas this paper aims to provide a quantitative method of examining changes in these structures by fluorescently labeling the element of interest and performing single cell image analysis. The method described herein tracks the diameter of the microtubule ring and the circumference of the actin matrix as they change over time. Platelets were incubated with a series of drugs that interact with tubulin or actin, and the platelets were observed for variation in shape change dynamics throughout the activation process. Differences in shape change mechanics due to drug incubation were observable in each case.
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16
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Diagouraga B, Grichine A, Fertin A, Wang J, Khochbin S, Sadoul K. Motor-driven marginal band coiling promotes cell shape change during platelet activation. ACTA ACUST UNITED AC 2014; 204:177-85. [PMID: 24421335 PMCID: PMC3897189 DOI: 10.1083/jcb.201306085] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During platelet activation, motor protein-induced coiling of the microtubule-based marginal band leads to the cells’ characteristic spherical shape, whereas actomyosin-mediated compression of the coil results in new microtubule polymerization in a smaller ring. Platelets float in the blood as discoid particles. Their shape is maintained by microtubules organized in a ring structure, the so-called marginal band (MB), in the periphery of resting platelets. Platelets are activated after vessel injury and undergo a major shape change known as disc to sphere transition. It has been suggested that actomyosin tension induces the contraction of the MB to a smaller ring. In this paper, we show that antagonistic microtubule motors keep the MB in its resting state. During platelet activation, dynein slides microtubules apart, leading to MB extension rather than contraction. The MB then starts to coil, thereby inducing the spherical shape of activating platelets. Newly polymerizing microtubules within the coiled MB will then take a new path to form the smaller microtubule ring, in concerted action with actomyosin tension. These results present a new view of the platelet activation mechanism and reveal principal mechanistic features underlying cellular shape changes.
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Affiliation(s)
- Boubou Diagouraga
- Institut Albert Bonniot, Institut National de la Santé et de la Recherche Médicale U823; and 2 Techniques de l'Ingénierie Médicale et de la Complexité-Informatique, Mathématiques et Applications, Grenoble, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5525; Université Joseph Fourier-Grenoble 1, F-38041 Grenoble, France
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17
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Actin in action: imaging approaches to study cytoskeleton structure and function. Cells 2013; 2:715-31. [PMID: 24709877 PMCID: PMC3972653 DOI: 10.3390/cells2040715] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 11/06/2013] [Accepted: 11/08/2013] [Indexed: 01/18/2023] Open
Abstract
The cytoskeleton plays several fundamental roles in the cell, including organizing the spatial arrangement of subcellular organelles, regulating cell dynamics and motility, providing a platform for interaction with neighboring cells, and ultimately defining overall cell shape. Fluorescence imaging has proved to be vital in furthering our understanding of the cytoskeleton, and is now a mainstay technique used widely by cell biologists. In this review we provide an introduction to various imaging modalities used to study focal adhesions and the actin cytoskeleton, and using specific examples we highlight a number of recent studies in animal cells that have advanced our knowledge of cytoskeletal behavior.
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