1
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Gavin RL, Koo CZ, Tomlinson MG. Tspan18 is a novel regulator of thrombo-inflammation. Med Microbiol Immunol 2020; 209:553-564. [PMID: 32447449 PMCID: PMC7395042 DOI: 10.1007/s00430-020-00678-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 05/06/2020] [Indexed: 12/18/2022]
Abstract
The interplay between thrombosis and inflammation, termed thrombo-inflammation, causes acute organ damage in diseases such as ischaemic stroke and venous thrombosis. We have recently identified tetraspanin Tspan18 as a novel regulator of thrombo-inflammation. The tetraspanins are a family of 33 membrane proteins in humans that regulate the trafficking, clustering, and membrane diffusion of specific partner proteins. Tspan18 partners with the store-operated Ca2+ entry channel Orai1 on endothelial cells. Orai1 appears to be expressed in all cells and is critical in health and disease. Orai1 mutations cause human immunodeficiency, resulting in chronic and often lethal infections, while Orai1-knockout mice die at around the time of birth. Orai1 is a promising drug target in autoimmune and inflammatory diseases, and Orai1 inhibitors are in clinical trials. The focus of this review is our work on Tspan18 and Orai1 in Tspan18-knockout mice and Tspan18-knockdown primary human endothelial cells. Orai1 trafficking to the cell surface is partially impaired in the absence of Tspan18, resulting in impaired Ca2+ signaling and impaired release of the thrombo-inflammatory mediator von Willebrand factor following endothelial stimulation. As a consequence, Tspan18-knockout mice are protected in ischemia-reperfusion and deep vein thrombosis models. We provide new evidence that Tspan18 is relatively highly expressed in endothelial cells, through the analysis of publicly available single-cell transcriptomic data. We also present new data, showing that Tspan18 is required for normal Ca2+ signaling in platelets, but the functional consequences are subtle and restricted to mildly defective platelet aggregation and spreading induced by the platelet collagen receptor GPVI. Finally, we generate structural models of human Tspan18 and Orai1 and hypothesize that Tspan18 regulates Orai1 Ca2+ channel function at the cell surface by promoting its clustering.
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Affiliation(s)
- Rebecca L Gavin
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Chek Ziu Koo
- School of Biosciences, University of Birmingham, Birmingham, UK
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2
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Ngo ATP, Jongen M, Shatzel JJ, McCarty OJT. Platelet integrin activation surfs the calcium waves. Platelets 2020; 32:437-439. [PMID: 32441552 DOI: 10.1080/09537104.2020.1768365] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Anh T P Ngo
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Maaike Jongen
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Joseph J Shatzel
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| | - Owen J T McCarty
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
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3
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Bye AP, Gibbins JM, Mahaut-Smith MP. Ca 2+ waves coordinate purinergic receptor-evoked integrin activation and polarization. Sci Signal 2020; 13:13/615/eaav7354. [PMID: 31964805 DOI: 10.1126/scisignal.aav7354] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cells sense extracellular nucleotides through the P2Y class of purinergic G protein-coupled receptors (GPCRs), which stimulate integrin activation through signaling events, including intracellular Ca2+ mobilization. We investigated the relationship between P2Y-stimulated repetitive Ca2+ waves and fibrinogen binding to the platelet integrin αIIbβ3 (GPIIb/IIIa) through confocal fluorescence imaging of primary rat megakaryocytes. Costimulation of the receptors P2Y1 and P2Y12 generated a series of Ca2+ transients that each induced a rapid, discrete increase in fibrinogen binding. The peak and net increase of individual fibrinogen binding events correlated with the Ca2+ transient amplitude and frequency, respectively. Using BAPTA loading and selective receptor antagonists, we found that Ca2+ mobilization downstream of P2Y1 was essential for ADP-evoked fibrinogen binding, whereas P2Y12 and the kinase PI3K were also required for αIIbβ3 activation and enhanced the number of Ca2+ transients. ADP-evoked fibrinogen binding was initially uniform over the cell periphery but subsequently redistributed with a polarity that correlated with the direction of the Ca2+ waves. Polarization of αIIbβ3 may be mediated by the actin cytoskeleton, because surface-bound fibrinogen is highly immobile, and its motility was enhanced by cytoskeletal disruption. In conclusion, spatial and temporal patterns of Ca2+ increase enable fine control of αIIbβ3 activation after cellular stimulation. P2Y1-stimulated Ca2+ transients coupled to αIIbβ3 activation only in the context of P2Y12 coactivation, thereby providing an additional temporal mechanism of synergy between these Gq- and Gi-coupled GPCRs.
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Affiliation(s)
- Alexander P Bye
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading RG6 6AS, UK.
| | - Jonathan M Gibbins
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading RG6 6AS, UK
| | - Martyn P Mahaut-Smith
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK.
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4
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Abstract
The vasculature is a dynamic environment in which blood platelets constantly survey the endothelium for sites of vessel damage. The formation of a mechanically coherent hemostatic plug to prevent blood loss relies on a coordinated series of ligand-receptor interactions governing the recruitment, activation, and aggregation of platelets. The physical biology of each step is distinct in that the recruitment of platelets depends on the mechanosensing of the platelet receptor glycoprotein Ib for the adhesive protein von Willebrand factor, whereas platelet activation and aggregation are responsive to the mechanical forces sensed at adhesive junctions between platelets and at the platelet-matrix interface. Herein we take a biophysical perspective to discuss the current understanding of platelet mechanotransduction as well as the measurement techniques used to quantify the physical biology of platelets in the context of thrombus formation under flow.
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Affiliation(s)
- Caroline E Hansen
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Yongzhi Qiu
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Owen J T McCarty
- Department of Cell, Developmental, and Cancer Biology, Oregon Health & Science University, Portland, Oregon 97239, USA.,Division of Hematology and Medical Oncology and Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Wilbur A Lam
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
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5
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Haining EJ, Matthews AL, Noy PJ, Romanska HM, Harris HJ, Pike J, Morowski M, Gavin RL, Yang J, Milhiet PE, Berditchevski F, Nieswandt B, Poulter NS, Watson SP, Tomlinson MG. Tetraspanin Tspan9 regulates platelet collagen receptor GPVI lateral diffusion and activation. Platelets 2017; 28:629-642. [PMID: 28032533 PMCID: PMC5706974 DOI: 10.1080/09537104.2016.1254175] [Citation(s) in RCA: 14] [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: 09/01/2016] [Revised: 10/06/2016] [Accepted: 10/20/2016] [Indexed: 12/14/2022]
Abstract
The tetraspanins are a superfamily of four-transmembrane proteins, which regulate the trafficking, lateral diffusion and clustering of the transmembrane proteins with which they interact. We have previously shown that tetraspanin Tspan9 is expressed on platelets. Here we have characterised gene-trap mice lacking Tspan9. The mice were viable with normal platelet numbers and size. Tspan9-deficient platelets were specifically defective in aggregation and secretion induced by the platelet collagen receptor GPVI, despite normal surface GPVI expression levels. A GPVI activation defect was suggested by partially impaired GPVI-induced protein tyrosine phosphorylation. In mechanistic experiments, Tspan9 and GPVI co-immunoprecipitated and co-localised, but super-resolution imaging revealed no defects in collagen-induced GPVI clustering on Tspan9-deficient platelets. However, single particle tracking using total internal reflection fluorescence microscopy showed that GPVI lateral diffusion was reduced by approximately 50% in the absence of Tspan9. Therefore, Tspan9 plays a fine-tuning role in platelet activation by regulating GPVI membrane dynamics.
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Affiliation(s)
- Elizabeth J. Haining
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Alexandra L. Matthews
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Peter J. Noy
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Helen J. Harris
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Jeremy Pike
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
- PSIBS Doctoral Training Centre, School of Chemistry, University of Birmingham, Birmingham, UK
| | - Martina Morowski
- Department of Experimental Biomedicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - Rebecca L. Gavin
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Jing Yang
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Pierre-Emmanuel Milhiet
- INSERM U1054, CNRS, UMR 5048, Centre de Biochimie Structurale, Montpellier University, France
| | - Fedor Berditchevski
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Bernhard Nieswandt
- Department of Experimental Biomedicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - Natalie S. Poulter
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Steve P. Watson
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Michael G. Tomlinson
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
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6
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De Zanet D, Battiston M, Lombardi E, Specogna R, Trevisan F, De Marco L, Affanni A, Mazzucato M. Impedance biosensor for real-time monitoring and prediction of thrombotic individual profile in flowing blood. PLoS One 2017; 12:e0184941. [PMID: 28922391 PMCID: PMC5602635 DOI: 10.1371/journal.pone.0184941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 09/01/2017] [Indexed: 12/31/2022] Open
Abstract
A new biosensor for the real-time analysis of thrombus formation is reported. The fast and accurate monitoring of the individual thrombotic risk represents a challenge in cardiovascular diagnostics and in treatment of hemostatic diseases. Thrombus volume, as representative index of the related thrombotic status, is usually estimated with confocal microscope at the end of each in vitro experiment, without providing a useful behavioral information of the biological sample such as platelets adhesion and aggregation in flowing blood. Our device has been developed to work either independently or integrated with the microscopy system; thus, images of the fluorescently labeled platelets are acquired in real-time during the whole blood perfusion, while the global electrical impedance of the blood sample is simultaneously monitored between a pair of specifically designed gold microelectrodes. Fusing optical and electrical data with a novel technique, the dynamic of thrombus formation events in flowing blood can be reconstructed in real-time, allowing an accurate extrapolation of the three-dimensional shape and the spatial distribution of platelet thrombi forming and growing within artificial capillaries. This biosensor is accurate and it has been used to discriminate different hemostatic conditions and to identify weakening and detaching platelet aggregates. The results obtained appear compatible with those quantified with the traditional optical method. With advantages in terms of small size, user-friendliness and promptness of response, it is a promising device for the fast and automatic individual health monitoring at the Point of Care (POC).
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Affiliation(s)
- Denise De Zanet
- Polytechnic Department of Engineering and Architecture, University of Udine, Udine, Italy
- Department of Translational Research, Stem Cells Unit, National Cancer Institute CRO - IRCCS, Aviano, Pordenone, Italy
| | - Monica Battiston
- Department of Translational Research, Stem Cells Unit, National Cancer Institute CRO - IRCCS, Aviano, Pordenone, Italy
| | - Elisabetta Lombardi
- Department of Translational Research, Stem Cells Unit, National Cancer Institute CRO - IRCCS, Aviano, Pordenone, Italy
| | - Ruben Specogna
- Polytechnic Department of Engineering and Architecture, University of Udine, Udine, Italy
| | - Francesco Trevisan
- Polytechnic Department of Engineering and Architecture, University of Udine, Udine, Italy
| | - Luigi De Marco
- Department of Translational Research, Stem Cells Unit, National Cancer Institute CRO - IRCCS, Aviano, Pordenone, Italy
| | - Antonio Affanni
- Polytechnic Department of Engineering and Architecture, University of Udine, Udine, Italy
| | - Mario Mazzucato
- Department of Translational Research, Stem Cells Unit, National Cancer Institute CRO - IRCCS, Aviano, Pordenone, Italy
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7
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Wei YP, Ye JW, Wang X, Zhu LP, Hu QH, Wang Q, Ke D, Tian Q, Wang JZ. Tau-Induced Ca 2+/Calmodulin-Dependent Protein Kinase-IV Activation Aggravates Nuclear Tau Hyperphosphorylation. Neurosci Bull 2017. [PMID: 28646348 DOI: 10.1007/s12264-017-0148-8] [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] [Indexed: 12/24/2022] Open
Abstract
Hyperphosphorylated tau is the major protein component of neurofibrillary tangles in the brains of patients with Alzheimer's disease (AD). However, the mechanism underlying tau hyperphosphorylation is not fully understood. Here, we demonstrated that exogenously expressed wild-type human tau40 was detectable in the phosphorylated form at multiple AD-associated sites in cytoplasmic and nuclear fractions from HEK293 cells. Among these sites, tau phosphorylated at Thr205 and Ser214 was almost exclusively found in the nuclear fraction at the conditions used in the present study. With the intracellular tau accumulation, the Ca2+ concentration was significantly increased in both cytoplasmic and nuclear fractions. Further studies using site-specific mutagenesis and pharmacological treatment demonstrated that phosphorylation of tau at Thr205 increased nuclear Ca2+ concentration with a simultaneous increase in the phosphorylation of Ca2+/calmodulin-dependent protein kinase IV (CaMKIV) at Ser196. On the other hand, phosphorylation of tau at Ser214 did not significantly change the nuclear Ca2+/CaMKIV signaling. Finally, expressing calmodulin-binding protein-4 that disrupts formation of the Ca2+/calmodulin complex abolished the okadaic acid-induced tau hyperphosphorylation in the nuclear fraction. We conclude that the intracellular accumulation of phosphorylated tau, as detected in the brains of AD patients, can trigger nuclear Ca2+/CaMKIV signaling, which in turn aggravates tau hyperphosphorylation. Our findings provide new insights for tauopathies: hyperphosphorylation of intracellular tau and an increased Ca2+ concentration may induce a self-perpetuating harmful loop to promote neurodegeneration.
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Affiliation(s)
- Yu-Ping Wei
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jin-Wang Ye
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Xiong Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Li-Ping Zhu
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing-Hua Hu
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qun Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dan Ke
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing Tian
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Zhi Wang
- Pathophysiology Department, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. .,Key Laboratory of Ministry of Education for Neurological Disorders and Hubei Provincial Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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8
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Pugh N, Maddox BD, Bihan D, Taylor KA, Mahaut-Smith MP, Farndale RW. Differential integrin activity mediated by platelet collagen receptor engagement under flow conditions. Thromb Haemost 2017; 117:1588-1600. [PMID: 28536721 PMCID: PMC6291897 DOI: 10.1160/th16-12-0906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/22/2017] [Indexed: 11/15/2022]
Abstract
The platelet receptors glycoprotein (Gp)VI, integrin α
2
β
1
and GpIb/V/IX mediate platelet adhesion and activation during thrombogenesis. Increases of intracellular Ca
2+
([Ca
2+
]
i
) are key signals during platelet activation; however, their relative importance in coupling different collagen receptors to functional responses under shear conditions remains unclear. To study shear-dependent, receptor-specific platelet responses, we used collagen or combinations of receptor-specific collagen-mimetic peptides as substrates for platelet adhesion and activation in whole human blood under arterial flow conditions and compared real-time and endpoint parameters of thrombus formation alongside [Ca
2+
]
i
measurements using confocal imaging. All three collagen receptors coupled to [Ca
2+
]
i
signals, but these varied in amplitude and temporal pattern alongside variable integrin activation. GpVI engagement produced large, sustained [Ca
2+
]
i
signals leading to realtime increases in integrins α
2
β
1
− and α
IIb
β
3
-mediated platelet adhesion. α
IIb
β
3
-dependent platelet aggregation was dependent on P
2
Y
12
signalling. Co-engagement of α
2
β
1
and GpIb/V/IX generated transient [Ca
2+
]
i
spikes and low amplitude [Ca
2+
]
i
responses that potentiated GpVI-dependent [Ca
2+
]
i
signalling. Therefore α
2
β
1
GpIb/V/IX and GpVI synergise to generate [Ca
2+
]
i
signals that regulate platelet behaviour and thrombus formation. Antagonism of secondary signalling pathways reveals distinct, separate roles for α
IIb
β
3
in stable platelet adhesion and aggregation.
Supplementary Material to this article is available online at
www.thrombosis-online.com
.
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Affiliation(s)
- Nicholas Pugh
- Nicholas Pugh, Department of Biomedical and Forensic Sciences, Anglia Ruskin University, Cambridge, CB1 1PT, UK, Tel.: +44 8451962661, E-mail:
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9
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Wang Y, Ni H. Fibronectin maintains the balance between hemostasis and thrombosis. Cell Mol Life Sci 2016; 73:3265-77. [PMID: 27098513 PMCID: PMC11108312 DOI: 10.1007/s00018-016-2225-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 03/27/2016] [Accepted: 04/12/2016] [Indexed: 11/29/2022]
Abstract
Fibronectin is a dimeric protein widely distributed in solid tissues and blood. This major extracellular matrix protein is indispensable for embryogenesis and plays crucial roles in many physiological and pathological processes. Fibronectin pre-mRNA undergoes alternative splicing to generate over 20 splicing variants, which are categorized as either plasma fibronectin (pFn) or cellular fibronectin (cFn). All fibronectin variants contain integrin binding motifs, as well as N-terminus collagen and fibrin binding motifs. With motifs that can be recognized by platelet integrins and coagulation factors, fibronectin, especially pFn, has long been suspected to be involved in hemostasis and thrombosis, but the exact function of fibronectin in these processes is controversial. The advances made using intravital microscopy models and fibronectin deficient and mutant mice have greatly facilitated the direct investigation of fibronectin function in vivo. Recent studies revealed that pFn is a vital hemostatic factor that is especially crucial for hemostasis in both genetic and anticoagulant-induced deficiencies of fibrin formation. pFn may also be an important self-limiting regulator to prevent hemorrhage as well as excessive thrombus formation and vessel occlusion. In addition to pFn, cFn is found to be prothrombotic and may contribute to thrombotic complications in various diseases. Further investigations of the role of pFn and cFn in thrombotic and hemorrhagic diseases may provide insights into development of novel therapeutic strategies (e.g., pFn transfusion) for the maintenance of the fine balance between hemostasis and thrombosis.
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Affiliation(s)
- Yiming Wang
- Room 420, LKSKI-Keenan Research Centre for Biomedical Science, Department of Laboratory Medicine, St. Michael's Hospital, 209 Victoria Street, Toronto, ON, M5B 1W8, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
- Canadian Blood Services, Toronto, ON, Canada
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada
| | - Heyu Ni
- Room 420, LKSKI-Keenan Research Centre for Biomedical Science, Department of Laboratory Medicine, St. Michael's Hospital, 209 Victoria Street, Toronto, ON, M5B 1W8, Canada.
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
- Canadian Blood Services, Toronto, ON, Canada.
- Toronto Platelet Immunobiology Group, Toronto, ON, Canada.
- Department of Physiology, University of Toronto, Toronto, ON, Canada.
- Department of Medicine, University of Toronto, Toronto, ON, Canada.
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10
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Münzer P, Walker-Allgaier B, Geue S, Geuss E, Hron G, Rath D, Eißler D, Winter S, Schaeffeler E, Meinert M, Schaller M, Greinacher A, Schwab M, Geisler T, Kleinschnitz C, Lang F, Gawaz M, Borst O. PDK1 Determines Collagen-Dependent Platelet Ca
2+
Signaling and Is Critical to Development of Ischemic Stroke In Vivo. Arterioscler Thromb Vasc Biol 2016; 36:1507-16. [DOI: 10.1161/atvbaha.115.307105] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 05/16/2016] [Indexed: 01/12/2023]
Abstract
Objective—
Activation of platelets by subendothelial collagen results in an increase of cytosolic Ca
2+
concentration ([Ca
2+
]
i
) and is followed by platelet activation and thrombus formation that may lead to vascular occlusion. The present study determined the role of phosphoinositide-dependent protein kinase 1 (PDK1) in collagen-dependent platelet Ca
2+
signaling and ischemic stroke in vivo.
Approach and Results—
Platelet activation with collagen receptor glycoprotein VI agonists collagen-related peptide or convulxin resulted in a significant increase in PDK1 activity independent of second-wave signaling. PDK1 deficiency was associated with reduced platelet phospholipase Cγ2–dependent inositol-1,4,5-trisphosphate production and intracellular [Ca
2+
]
i
in response to stimulation with collagen-related peptide or convulxin. The defective increase of [Ca
2+
]
i
resulted in a substantial defect in activation-dependent platelet secretion and aggregation on collagen-related peptide stimulation. Furthermore, Rac1 activation and spreading, adhesion to collagen, and thrombus formation under high arterial shear rates were significantly diminished in PDK1-deficient platelets. Mice with PDK1-deficient platelets were protected against arterial thrombotic occlusion after FeCl
3
-induced mesenteric arterioles injury and ischemic stroke in vivo. These mice had significantly reduced brain infarct volumes, with a significantly increased survival of 7 days after transient middle cerebral artery occlusion without increase of intracerebral hemorrhage. Tail bleeding time was prolonged in
pdk1
−/−
mice, reflecting an important role of PDK1 in primary hemostasis.
Conclusions—
PDK1 is required for Ca
2+
-dependent platelet activation on stimulation of collagen receptor glycoprotein VI, arterial thrombotic occlusion, and ischemic stroke in vivo.
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Affiliation(s)
- Patrick Münzer
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Britta Walker-Allgaier
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Sascha Geue
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Eva Geuss
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Gregor Hron
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Dominik Rath
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Daniela Eißler
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Stefan Winter
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Elke Schaeffeler
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Monika Meinert
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Martin Schaller
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Andreas Greinacher
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Matthias Schwab
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Tobias Geisler
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Christoph Kleinschnitz
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Florian Lang
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Meinrad Gawaz
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
| | - Oliver Borst
- From the Department of Cardiology and Cardiovascular Medicine (P.M., B.W.-A., S.G., D.R., D.E., T.G., M.G., O.B.), Department of Physiology (B.W.-A., F.L.), Department of Evolutionary Biology of Invertebrates, Institute for Evolution and Ecology (M.M.), Department of Dermatology (M.S.), and Department of Clinical Pharmacology (M.S.), University of Tübingen, Tübingen, Germany; Department of Neurology, University of Würzburg, Würzburg, Germany (E.G., C.K.); Institute for Immunology and Transfusion
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11
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Xu XR, Zhang D, Oswald BE, Carrim N, Wang X, Hou Y, Zhang Q, Lavalle C, McKeown T, Marshall AH, Ni H. Platelets are versatile cells: New discoveries in hemostasis, thrombosis, immune responses, tumor metastasis and beyond. Crit Rev Clin Lab Sci 2016; 53:409-30. [PMID: 27282765 DOI: 10.1080/10408363.2016.1200008] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Platelets are small anucleate blood cells generated from megakaryocytes in the bone marrow and cleared in the reticuloendothelial system. At the site of vascular injury, platelet adhesion, activation and aggregation constitute the first wave of hemostasis. Blood coagulation, which is initiated by the intrinsic or extrinsic coagulation cascades, is the second wave of hemostasis. Activated platelets can also provide negatively-charged surfaces that harbor coagulation factors and markedly potentiate cell-based thrombin generation. Recently, deposition of plasma fibronectin, and likely other plasma proteins, onto the injured vessel wall has been identified as a new "protein wave of hemostasis" that may occur even earlier than the first wave of hemostasis, platelet accumulation. Although no experimental evidence currently exists, it is conceivable that platelets may also contribute to this protein wave of hemostasis by releasing their granule fibronectin and other proteins that may facilitate fibronectin self- and non-self-assembly on the vessel wall. Thus, platelets may contribute to all three waves of hemostasis and are central players in this critical physiological process to prevent bleeding. Low platelet counts in blood caused by enhanced platelet clearance and/or impaired platelet production are usually associated with hemorrhage. Auto- and allo-immune thrombocytopenias such as idiopathic thrombocytopenic purpura and fetal and neonatal alloimmune thrombocytopenia may cause life-threatening bleeding such as intracranial hemorrhage. When triggered under pathological conditions such as rupture of an atherosclerotic plaque, excessive platelet activation and aggregation may result in thrombosis and vessel occlusion. This may lead to myocardial infarction or ischemic stroke, the major causes of mortality and morbidity worldwide. Platelets are also involved in deep vein thrombosis and thromboembolism, another leading cause of mortality. Although fibrinogen has been documented for more than half a century as essential for platelet aggregation, recent studies demonstrated that fibrinogen-independent platelet aggregation occurs in both gene deficient animals and human patients under physiological and pathological conditions (non-anti-coagulated blood). This indicates that other unidentified platelet ligands may play important roles in thrombosis and might be novel antithrombotic targets. In addition to their critical roles in hemostasis and thrombosis, emerging evidence indicates that platelets are versatile cells involved in many other pathophysiological processes such as innate and adaptive immune responses, atherosclerosis, angiogenesis, lymphatic vessel development, liver regeneration and tumor metastasis. This review summarizes the current knowledge of platelet biology, highlights recent advances in the understanding of platelet production and clearance, molecular and cellular events of thrombosis and hemostasis, and introduces the emerging roles of platelets in the immune system, vascular biology and tumorigenesis. The clinical implications of these basic science and translational research findings will also be discussed.
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Affiliation(s)
- Xiaohong Ruby Xu
- a Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto , ON , Canada .,b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,c Department of Medicine , Guangzhou University of Chinese Medicine , Guangzhou , Guangdong , P.R. China
| | - Dan Zhang
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,c Department of Medicine , Guangzhou University of Chinese Medicine , Guangzhou , Guangdong , P.R. China
| | - Brigitta Elaine Oswald
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,d Canadian Blood Services , Toronto , ON , Canada .,e Department of Physiology , University of Toronto , Toronto , ON , Canada
| | - Naadiya Carrim
- a Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto , ON , Canada .,b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,d Canadian Blood Services , Toronto , ON , Canada
| | - Xiaozhong Wang
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,f The Second Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , P.R. China
| | - Yan Hou
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,g Jilin Provincial Center for Disease Prevention and Control , Changchun , Jilin , P.R. China
| | - Qing Zhang
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,h State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University , Guangzhou , Guangdong , P.R. China , and
| | - Christopher Lavalle
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,e Department of Physiology , University of Toronto , Toronto , ON , Canada
| | - Thomas McKeown
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada
| | - Alexandra H Marshall
- b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada
| | - Heyu Ni
- a Department of Laboratory Medicine and Pathobiology , University of Toronto , Toronto , ON , Canada .,b Department of Laboratory Medicine , Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Toronto Platelet Immunobiology Group, Li Ka Shing Knowledge Institute , Toronto , ON , Canada .,d Canadian Blood Services , Toronto , ON , Canada .,e Department of Physiology , University of Toronto , Toronto , ON , Canada .,i Department of Medicine , University of Toronto , Toronto , ON , Canada
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12
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Lysyl oxidase is associated with increased thrombosis and platelet reactivity. Blood 2016; 127:1493-501. [PMID: 26755713 DOI: 10.1182/blood-2015-02-629667] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 12/17/2015] [Indexed: 01/26/2023] Open
Abstract
Lysyl oxidase (LOX) is overexpressed in various pathologies associated with thrombosis, such as arterial stenosis and myeloproliferative neoplasms (MPNs). LOX is elevated in the megakaryocytic lineage of mouse models of MPNs and in patients with MPNs. To gain insight into the role of LOX in thrombosis and platelet function without compounding the influences of other pathologies, transgenic mice expressing LOX in wild-type megakaryocytes and platelets (Pf4-Lox(tg/tg)) were generated. Pf4-Lox(tg/tg) mice had a normal number of platelets; however, time to vessel occlusion after endothelial injury was significantly shorter in Pf4-Lox(tg/tg) mice, indicating a higher propensity for thrombus formation in vivo. Exploring underlying mechanisms, we found that Pf4-Lox(tg/tg) platelets adhere better to collagen and have greater aggregation response to lower doses of collagen compared with controls. Platelet activation in response to the ligand for collagen receptor glycoprotein VI (cross-linked collagen-related peptide) was unaffected. However, the higher affinity of Pf4-Lox(tg/tg) platelets to the collagen sequence GFOGER implies that the collagen receptor integrin α2β1 is affected by LOX. Taken together, our findings demonstrate that LOX enhances platelet activation and thrombosis.
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13
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Di Buduo CA, Wray LS, Tozzi L, Malara A, Chen Y, Ghezzi CE, Smoot D, Sfara C, Antonelli A, Spedden E, Bruni G, Staii C, De Marco L, Magnani M, Kaplan DL, Balduini A. Programmable 3D silk bone marrow niche for platelet generation ex vivo and modeling of megakaryopoiesis pathologies. Blood 2015; 125:2254-64. [PMID: 25575540 PMCID: PMC4383799 DOI: 10.1182/blood-2014-08-595561] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 01/03/2015] [Indexed: 01/16/2023] Open
Abstract
We present a programmable bioengineered 3-dimensional silk-based bone marrow niche tissue system that successfully mimics the physiology of human bone marrow environment allowing us to manufacture functional human platelets ex vivo. Using stem/progenitor cells, megakaryocyte function and platelet generation were recorded in response to variations in extracellular matrix components, surface topography, stiffness, coculture with endothelial cells, and shear forces. Millions of human platelets were produced and showed to be functional based on multiple activation tests. Using adult hematopoietic progenitor cells our system demonstrated the ability to reproduce key steps of thrombopoiesis, including alterations observed in diseased states. A critical feature of the system is the use of natural silk protein biomaterial allowing us to leverage its biocompatibility, nonthrombogenic features, programmable mechanical properties, and surface binding of cytokines, extracellular matrix components, and endothelial-derived proteins. This in turn offers new opportunities for the study of blood component production ex vivo and provides a superior tissue system for the study of pathologic mechanisms of human platelet production.
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Affiliation(s)
- Christian A Di Buduo
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Foundation, Pavia, Italy
| | - Lindsay S Wray
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Foundation, Pavia, Italy; Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Lorenzo Tozzi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Foundation, Pavia, Italy; Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Alessandro Malara
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Foundation, Pavia, Italy
| | - Ying Chen
- Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Daniel Smoot
- Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Carla Sfara
- Department of Biomolecular Sciences, Biochemistry and Molecular Biology Section, University of Urbino "Carlo Bo," Urbino, Italy
| | - Antonella Antonelli
- Department of Biomolecular Sciences, Biochemistry and Molecular Biology Section, University of Urbino "Carlo Bo," Urbino, Italy
| | - Elise Spedden
- Department of Physics, Tufts University, Medford, MA
| | - Giovanna Bruni
- Department of Chemistry, Physical Chemistry Section, University of Pavia, Pavia, Italy
| | | | - Luigi De Marco
- Department of Translational Research, Stem Cells Unit, Istituto di Ricovero e Cura a Carattere Scientifico Centro di Riferimento Oncologico, Aviano, Italy; and Department of Molecular and Experimental Research, The Scripps Research Institute, La Jolla, CA
| | - Mauro Magnani
- Department of Biomolecular Sciences, Biochemistry and Molecular Biology Section, University of Urbino "Carlo Bo," Urbino, Italy
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA
| | - Alessandra Balduini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Biotechnology Research Laboratories, Istituto di Ricovero e Cura a Carattere Scientifico San Matteo Foundation, Pavia, Italy; Department of Biomedical Engineering, Tufts University, Medford, MA
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14
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Visualization of nitric oxide production by individual platelets during adhesion in flowing blood. Blood 2014; 125:697-705. [PMID: 25480660 DOI: 10.1182/blood-2014-06-579474] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Nitric oxide (NO) exerts vasodilatatory, antiplatelet, antioxidant, and antiproliferative effects. Endothelium-derived NO has been shown to be of crucial importance in cardiovascular protection, whereas evidence that NO is synthesized by platelets and regulates platelet function is still controversial. By using a sensitive and specific fluorescent probe, 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate (DAF-FM), we visualized NO production in individual platelets undergoing adhesion on a collagen substrate under flow conditions. NO production, monitored in real time, was dependent on the shear rates applied, increasing with the raising of the shear rates. Furthermore, NO production increased in the presence of l-arginine (nitric-oxide synthase [NOS] substrate), and it decreased in the presence of L-NG-monomethyl arginine (L-NMMA) (NOS inhibitor) but not of D-NG-monomethyl arginine (D-NMMA) (L-NMMA-inactive enantiomer). Platelet deposition, measured with mepacrine-labeled platelets, was inversely related to NO production. A correlation was evident between Ca(++) elevation and NO production, suggesting that platelet NO formation is triggered by intracytoplasmic Ca(++) elevation. Simultaneous measurement of NO and Ca(++) indicated that NO production in individual platelets is preceded by Ca(++) elevations, with a lag phase of 33 ± 9.5 s. Our studies provide the first direct demonstration of platelet NO production triggered by the interaction with an activating surface under flow and suggest that intraplatelet Ca(++) elevation elicits the production of NO which, in turn, modulates thrombus size.
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15
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Marjoram RJ, Li Z, He L, Tollefsen DM, Kunicki TJ, Dickeson SK, Santoro SA, Zutter MM. α2β1 integrin, GPVI receptor, and common FcRγ chain on mouse platelets mediate distinct responses to collagen in models of thrombosis. PLoS One 2014; 9:e114035. [PMID: 25415203 PMCID: PMC4240667 DOI: 10.1371/journal.pone.0114035] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 11/03/2014] [Indexed: 12/29/2022] Open
Abstract
Objective Platelets express the α2β1 integrin and the glycoprotein VI (GPVI)/FcRγ complex, both collagen receptors. Understanding platelet-collagen receptor function has been enhanced through use of genetically modified mouse models. Previous studies of GPVI/FcRγ-mediated collagen-induced platelet activation were perfomed with mice in which the FcRγ subunit was genetically deleted (FcRγ−/−) or the complex was depleted. The development of α2β1−/− and GPVI−/− mice permits side-by-side comparison to address contributions of these collagen receptors in vivo and in vitro. Approach and Results To understand the different roles played by the α2β1 integrin, the GPVI receptor or FcRγ subunit in collagen-stimulated hemostasis and thrombosis, we compared α2β1−/−, FcRγ−/−, and GPVI−/− mice in models of endothelial injury and intravascular thrombosis in vivo and their platelets in collagen-stimulated activation in vitro. We demonstrate that both the α2β1 integrin and the GPVI receptor, but not the FcRγ subunit influence carotid artery occlusion in vivo. In contrast, the GPVI receptor and the FcRγ chain, but not the α2β1 integrin, play similar roles in intravascular thrombosis in response to soluble Type I collagen. FcRγ−/− platelets showed less attenuation of tyrosine phosphorylation of several proteins including RhoGDI when compared to GPVI−/− and wild type platelets. The difference between FcRγ−/− and GPVI−/− platelet phosphotyrosine levels correlated with the in vivo thrombosis findings. Conclusion Our data demonstrate that genetic deletion of GPVI receptor, FcRγ chain, or the α2β1 integrin changes the thrombotic potentials of these platelets to collagen dependent on the stimulus mechanism. The data suggest that the FcRγ chain may provide a dominant negative effect through modulating signaling pathways in platelets involving several tyrosine phosphorylated proteins such as RhoGDI. In addition, these findings suggest a more complex signaling network downstream of the platelet collagen receptors than previously appreciated.
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Affiliation(s)
- Robin J. Marjoram
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Zhengzhi Li
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Li He
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Douglas M. Tollefsen
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States of America
| | - Thomas J. Kunicki
- Children's Hospital of Orange County, Orange, CA, United States of America
| | - S. Kent Dickeson
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Samuel A. Santoro
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
| | - Mary M. Zutter
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States of America
- * E-mail:
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16
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Carnevale R, Bartimoccia S, Nocella C, Di Santo S, Loffredo L, Illuminati G, Lombardi E, Boz V, Del Ben M, De Marco L, Pignatelli P, Violi F. LDL oxidation by platelets propagates platelet activation via an oxidative stress-mediated mechanism. Atherosclerosis 2014; 237:108-16. [DOI: 10.1016/j.atherosclerosis.2014.08.041] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/29/2014] [Accepted: 08/13/2014] [Indexed: 10/24/2022]
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17
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STIM1 calcium sensor is required for activation of the phagocyte oxidase during inflammation and host defense. Blood 2014; 123:2238-49. [PMID: 24493668 DOI: 10.1182/blood-2012-08-450403] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The stromal-interacting molecule 1 (STIM1) is a potent sensor of intracellular calcium, which in turn regulates entry of external calcium through plasma membrane channels to affect immune cell activation. Although the contribution of STIM1 to calcium signaling in lymphocytes has been well studied, the role of this protein in neutrophil-mediated inflammation and host defense is unknown. We report that STIM1-deficient murine neutrophils show loss of store-operated calcium entry (SOCE) in response to both soluble ligands that activate G-proteins as well as Fcγ-receptor or integrin ligation that activates tyrosine kinase signaling. This results in modest defects in phagocytosis and degranulation responses but a profound block in superoxide production by the phagocyte oxidase. We trace the primary intracellular target of calcium to be protein kinase C isoforms α and β (PKCα and PKCβ), which in turn phosphorylate subunits of the oxidase leading to superoxide production. In vivo the loss of SOCE in stim1(-/-) chimeric mice results in marked susceptibility to bacterial infections but also protection from tissue injury in hepatic ischemia/reperfusion injury. These results demonstrate the critical role of STIM1-mediated SOCE and define major protein targets of calcium signaling in neutrophil activation during inflammatory disease.
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18
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Madamanchi A, Santoro SA, Zutter MM. α2β1 Integrin. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 819:41-60. [PMID: 25023166 DOI: 10.1007/978-94-017-9153-3_3] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The α2β1 integrin, also known as VLA-2, GPIa-IIa, CD49b, was first identified as an extracellular matrix receptor for collagens and/or laminins [55, 56]. It is now recognized that the α2β1 integrin serves as a receptor for many matrix and nonmatrix molecules [35, 79, 128]. Extensive analyses have clearly elucidated the α2 I domain structural motifs required for ligand binding, and also defined distinct conformations that lead to inactive, partially active or highly active ligand binding [3, 37, 66, 123, 136, 137, 140]. The mechanisms by which the α2β1 integrin plays a critical role in platelet function and homeostasis have been carefully defined via in vitro and in vivo experiments [76, 104, 117, 125]. Genetic and epidemiologic studies have confirmed human physiology and disease states mediated by this receptor in immunity, cancer, and development [6, 20, 21, 32, 43, 90]. The role of the α2β1 integrin in these multiple complex biologic processes will be discussed in the chapter.
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Affiliation(s)
- Aasakiran Madamanchi
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Zahid M, Mangin P, Loyau S, Hechler B, Billiald P, Gachet C, Jandrot-Perrus M. The future of glycoprotein VI as an antithrombotic target. J Thromb Haemost 2012; 10:2418-27. [PMID: 23020554 DOI: 10.1111/jth.12009] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The treatment of acute coronary syndromes has been considerably improved in recent years with the introduction of highly efficient antiplatelet drugs. However, there are still significant limitations: the recurrence of adverse vascular events remains a problem, and the improvement in efficacy is counterbalanced by an increased risk of bleeding, which is of particular importance in patients at risk of stroke. One of the most attractive targets for the development of new molecules with potential antithrombotic activity is platelet glycoprotein (GP)VI, because its blockade appears to ideally combine efficacy and safety. This review summarizes current knowledge on GPVI regarding its structure, its function, and its role in physiologic hemostasis and thrombosis. Strategies for inhibiting GPVI are presented, and evidence of the antithrombotic efficacy and safety of GPVI antagonists is provided.
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Affiliation(s)
- M Zahid
- Inserm, UMRS_698, Paris, France
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21
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Fennewald SM, Kantara C, Sastry SK, Resto VA. Laminin interactions with head and neck cancer cells under low fluid shear conditions lead to integrin activation and binding. J Biol Chem 2012; 287:21058-66. [PMID: 22547070 DOI: 10.1074/jbc.m112.360313] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Lymphatic metastasis of cancer cells involves movement from the primary tumor site to the lymph node, where the cells must be able to productively lodge and grow. It is there that tumor cells encounter cellular and non-cellular constituent elements that make up the lymph node parenchyma. Our work shows that head and neck squamous cell carcinoma (HNSCC) cell lines are able to bind to laminin, fibronectin, vitronectin, and hyaluronic acid, which are extracellular matrix elements within the lymph node parenchyma. HNSCC cell lines bound to laminin under lymphodynamic low shear stress (0.07 dynes/cm(2)), consistent with lymph flow via β1 integrins, including α2β1, α3β1, and α6β1. Binding occurred in the presence of shear stress and not in the absence of flow. Additionally, tumor cell binding to laminin under flow did result in calcium signaling. Our data indicate a novel role for β1 integrin-mediated binding of HNSCC cells to laminin under conditions of lymphodynamic flow that results in intracellular calcium signaling within the cancer cell.
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Affiliation(s)
- Susan M Fennewald
- Department of Otolaryngology, UTMB Health, University of Texas Medical Branch, Galveston, Texas 77555-0521, USA
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22
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Park JY, Oh WJ, Kim MJ, Kim TH, Cho JY, Park HJ, Lee IK, Kim S, Kim GS, Kim SK, Seo GS, Yun BS, Rhee MH. Mechanism of anti-platelet activity of Oligoporus tephroleucus oligoporin A: involvement of extracellular signal-regulated kinase phosphorylation and cyclic nucleotide elevation. Platelets 2012; 23:376-85. [PMID: 22309049 DOI: 10.3109/09537104.2011.629309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This study investigated the inhibitory effects of oligoporin A on platelet aggregation and the mechanism of its action on downstream signaling molecules. Oligoporin A was isolated from the fruiting bodies of Oligoporus tephroleucus (Polyporaceae). The anti-platelet activities of oligoporin A were studied using rat platelets. The effects of oligoporin A on intracellular Ca(2+) mobilization, ATP release, production of the cyclic nucleotides cAMP and cGMP, extracellular signal-regulated kinase (ERK) 2 phosphorylation, and fibrinogen binding to active integrin α(II)(b)β(3) were assessed. Oligoporin A, but not oligoporins B and C, inhibited collagen-induced platelet aggregation in a concentration-dependent manner. Interestingly, oligoporin A did not affect ADP- and thrombin-induced platelet aggregations, which act on different types of membrane receptors. Granule secretion analysis demonstrated that oligoporin A significantly and dose-dependently reduced collagen-induced ATP release and intracellular Ca(2+) mobilization. Additionally, oligoporin A induced the dynamic increase in cAMP and cGMP. Increased cGMP production was further confirmed by the simultaneous production of nitric oxide. Pretreatment with oligoporin A significantly blocked collagen-induced ERK2 phosphorylation. Finally, oligoporin A vaguely diminished the binding of fibrinogen to its cognate receptor, integrin α(II)(b)β(3). The results indicate that oligoporin A inhibits only collagen-induced platelet aggregation mediated through the modulation of downstream signaling molecules. Oligoporin A may be beneficial against cardiovascular disease provoked by aberrant platelet activation.
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Affiliation(s)
- Ji Young Park
- College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Republic of Korea
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23
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Jarvis GE, Bihan D, Hamaia S, Pugh N, Ghevaert CJG, Pearce AC, Hughes CE, Watson SP, Ware J, Rudd CE, Farndale RW. A role for adhesion and degranulation-promoting adapter protein in collagen-induced platelet activation mediated via integrin α(2) β(1). J Thromb Haemost 2012; 10:268-77. [PMID: 22103309 PMCID: PMC3791415 DOI: 10.1111/j.1538-7836.2011.04567.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Collagen-induced platelet activation is a key step in the development of arterial thrombosis via its interaction with the receptors glycoprotein (GP)VI and integrin α(2) β(1) . Adhesion and degranulation-promoting adapter protein (ADAP) regulates α(IIb) β(3) in platelets and α(L) β(2) in T cells, and is phosphorylated in GPVI-deficient platelets activated by collagen. OBJECTIVES To determine whether ADAP plays a role in collagen-induced platelet activation and in the regulation and function of α(2) β(1). METHODS Using ADAP(-/-) mice and synthetic collagen peptides, we investigated the role of ADAP in platelet aggregation, adhesion, spreading, thromboxane synthesis, and tyrosine phosphorylation. RESULTS AND CONCLUSIONS Platelet aggregation and phosphorylation of phospholipase Cγ2 induced by collagen were attenuated in ADAP(-/-) platelets. However, aggregation and signaling induced by collagen-related peptide (CRP), a GPVI-selective agonist, were largely unaffected. Platelet adhesion to CRP was also unaffected by ADAP deficiency. Adhesion to the α(2) β(1) -selective ligand GFOGER and to a peptide (III-04), which supports adhesion that is dependent on both GPVI and α(2) β(1), was reduced in ADAP(-/-) platelets. An impedance-based label-free detection technique, which measures adhesion and spreading of platelets, indicated that, in the absence of ADAP, spreading on GFOGER was also reduced. This was confirmed with non-fluorescent differential-interference contrast microscopy, which revealed reduced filpodia formation in ADAP(-/-) platelets adherent to GFOGER. This indicates that ADAP plays a role in mediating platelet activation via the collagen-binding integrin α(2) β(1). In addition, we found that ADAP(-/-) mice, which are mildly thrombocytopenic, have enlarged spleens as compared with wild-type animals. This may reflect increased removal of platelets from the circulation.
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Affiliation(s)
- G E Jarvis
- School of Pharmacy, Queen's University Belfast, Belfast, UK.
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24
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A live cell micro-imaging technique to examine platelet calcium signaling dynamics under blood flow. Methods Mol Biol 2012; 788:73-89. [PMID: 22130701 DOI: 10.1007/978-1-61779-307-3_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The platelet is a specialized adhesive cell that plays a key role in thrombus formation under both physiological and pathological blood flow conditions. Platelet adhesion and activation are dynamic processes associated with rapid morphological and functional changes, with the earliest signaling events occurring over a subsecond time-scale. The relatively small size of platelets combined with the dynamic nature of platelet adhesion under blood flow means that the investigation of platelet signaling events requires techniques with both high spatial discrimination and rapid temporal resolution. Unraveling the complex signaling processes governing platelet adhesive function under conditions of hemodynamic shear stress has been a longstanding goal in platelet research and has been greatly influenced by the development and application of microimaging-based techniques. Advances in the area of epi-fluorescence and confocal-based platelet calcium (Ca(2+)) imaging have facilitated the in vitro and in vivo elucidation of the early signaling events regulating platelet adhesion and activation. These studies have identified distinct Ca(2+) signaling mechanisms that serve to dynamically regulate activation of the major platelet integrin α(IIb)β(3) and associated adhesion and aggregation processes under flow. This chapter describes in detail a ratiometric calcium imaging protocol and associated troubleshooting procedures developed in our laboratory to examine live platelet Ca(2+) signaling dynamics. This technique provides a method for high-resolution imaging of the Ca(2+) dynamics underpinning platelet adhesion and thrombus formation under conditions of pathophysiological shear stress.
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25
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Abstract
Integrin α2β1-mediated adhesion of human platelets to monomeric type I collagen or to the GFOGER peptide caused a time-dependent activation of PI3K and Akt phosphorylation. This process was abrogated by pharmacologic inhibition of PI3Kβ, but not of PI3Kγ or PI3Kα. Moreover, Akt phosphorylation was undetectable in murine platelets expressing a kinase-dead mutant of PI3Kβ (PI3Kβ(KD)), but occurred normally in PI3Kγ(KD) platelets. Integrin α2β1 failed to stimulate PI3Kβ in platelets from phospholipase Cγ2 (PLCγ2)-knockout mice, and we found that intracellular Ca(2+) linked PLCγ2 to PI3Kβ activation. Integrin α2β1 also caused a time-dependent stimulation of the focal kinase Pyk2 downstream of PLCγ2 and intracellular Ca(2+). Whereas activation of Pyk2 occurred normally in PI3Kβ(KD) platelets, stimulation of PI3Kβ was strongly reduced in Pyk2-knockout mice. Neither Pyk2 nor PI3Kβ was required for α2β1-mediated adhesion and spreading. However, activation of Rap1b and inside-out stimulation of integrin αIIbβ3 were reduced after inhibition of PI3Kβ and were significantly impaired in Pyk2-deficient platelets. Finally, both PI3Kβ and Pyk2 significantly contributed to thrombus formation under flow. These results demonstrate that Pyk2 regulates PI3Kβ downstream of integrin α2β1, and document a novel role for Pyk2 and PI3Kβ in integrin α2β1 promoted inside-out activation of integrin αIIbβ3 and thrombus formation.
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26
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Abstract
Collagen, the most abundant protein in animals, is a key component of extracellular matrices. Not only do collagens provide essential structural support for connective tissues, but they are also intimately involved in controlling a spectrum of cellular functions such as growth, differentiation, and morphogenesis. All collagens possess triple-helical regions through which they interact with a host of other proteins including cell surface receptors. A structurally diverse group of transmembrane receptors mediates the recognition of the collagen triple helix: integrins, discoidin domain receptors, glycoprotein VI, and leukocyte-associated immunoglobulin-like receptor-1. These collagen receptors regulate a wide range of behaviors including cell adhesion and migration, hemostasis, and immune function. Here these collagen receptors are discussed in terms of their molecular basis of collagen recognition, their signaling and developmental functions, and their roles in disease.
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Affiliation(s)
- Birgit Leitinger
- National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom.
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Ma C, Yao Y, Yue QX, Zhou XW, Yang PY, Wu WY, Guan SH, Jiang BH, Yang M, Liu X, Guo DA. Differential proteomic analysis of platelets suggested possible signal cascades network in platelets treated with salvianolic acid B. PLoS One 2011; 6:e14692. [PMID: 21379382 PMCID: PMC3040754 DOI: 10.1371/journal.pone.0014692] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2010] [Accepted: 01/25/2011] [Indexed: 11/19/2022] Open
Abstract
Background Salvianolic acid B (SB) is an active component isolated from Danshen, a traditional Chinese medicine widely used for the treatment of cardiovascular disorders. Previous study suggested that SB might inhibit adhesion as well as aggregation of platelets by a mechanism involving the integrin α2β1. But, the signal cascades in platelets after SB binding are still not clear. Methodology/Principal Findings In the present study, a differential proteomic analysis (two-dimensional electrophoresis) was conducted to check the protein expression profiles of rat platelets with or without treatment of SB. Proteins altered in level after SB exposure were identified by MALDI-TOF MS/MS. Treatment of SB caused regulation of 20 proteins such as heat shock-related 70 kDa protein 2 (hsp70), LIM domain protein CLP-36, copine I, peroxiredoxin-2, coronin-1 B and cytoplasmic dynein intermediate chain 2C. The regulation of SB on protein levels was confirmed by Western blotting. The signal cascades network induced by SB after its binding with integrin α2β1 was predicted. To certify the predicted network, binding affinity of SB to integrin α2β1 was checked in vitro and ex vivo in platelets. Furthermore, the effects of SB on protein levels of hsp70, coronin-1B and intracellular levels of Ca(2+) and reactive oxygen species (ROS) were checked with or without pre-treatment of platelets using antibody against integrin α2β1. Electron microscopy study confirmed that SB affected cytoskeleton structure of platelets. Conclusions/Significance Integrin α2β1 might be one of the direct target proteins of SB in platelets. The signal cascades network of SB after binding with integrin α2β1 might include regulation of intracellular Ca(2+) level, cytoskeleton-related proteins such as coronin-1B and cytoskeleton structure of platelets.
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Affiliation(s)
- Chao Ma
- Shanghai Research Center for Modernization of Traditional Chinese Medicine, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People's Republic of China
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28
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Eraso LH, Reilly MP, Sehgal C, Mohler ER. Emerging diagnostic and therapeutic molecular imaging applications in vascular disease. Vasc Med 2011; 16:145-56. [PMID: 21310769 DOI: 10.1177/1358863x10392474] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Assessment of vascular disease has evolved from mere indirect and direct measurements of luminal stenosis to sophisticated imaging methods to depict millimeter structural changes of the vasculature. In the near future, the emergence of multimodal molecular imaging strategies may enable robust therapeutic and diagnostic ('theragnostic') approaches to vascular diseases that comprehensively consider structural, functional, biological and genomic characteristics of the disease in individualized risk assessment, early diagnosis and delivery of targeted interventions.This review presents a summary of recent preclinical and clinical developments in molecular imaging and theragnostic applications covering diverse atherosclerosis events such as endothelial activation, macrophage inflammatory activity, plaque neovascularization and arterial thrombosis. The main focus is on molecular targets designed for imaging platforms commonly used in clinical medicine including magnetic resonance, computed tomography and positron emission tomography. A special emphasis is given to vascular ultrasound applications, considering the important role this imaging platform plays in the clinical and research practice of the vascular medicine specialty.
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Affiliation(s)
- Luis H Eraso
- Cardiovascular Division, Vascular Medicine Section, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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Platelet integrin signaling: wherefore art thou? Blood 2009; 114:2571-2. [DOI: 10.1182/blood-2009-08-235283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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