Faculty Opinions recommendation of Coagulation-induced shedding of platelet glycoprotein VI mediated by factor Xa.

Abstract This study evaluated shedding of the platelet collagen receptor, glycoprotein VI (GPVI) in human plasma. Collagen or other ligands induce metalloproteinase-mediated GPVI ectodomain shedding, generating approximately 55-kDa soluble GPVI (sGPVI) and approximately 10-kDa platelet-associated fragments. In the absence of GPVI ligands, coagulation of platelet-rich plasma from healthy persons induced GPVI shedding, independent of added tissue factor, but inhibitable by metalloproteinase inhibitor, GM6001. Factor Xa (FXa) common to intrinsic and tissue factor-mediated coagulation pathways was critical for sGPVI release because (1) shedding was strongly blocked by the FXa-selective inhibitor rivaroxaban but not FIIa (thrombin) inhibitors dabigatran or hirudin; (2) Russell viper venom that directly activates FX generated sGPVI, with complete inhibition by enoxaparin (inhibits FXa and FIIa) but not hirudin; (3) impaired GPVI shedding during coagulation of washed platelets resuspended in FX-depleted plasma was restored by adding purified FX; and (4) purified FXa induced GM6001-inhibitable GPVI shedding from washed platelets. In 29 patients with disseminated intravascular coagulation, mean plasma sGPVI was 53.9 ng/mL (95% confidence interval, 39.9-72.8 ng/mL) compared with 12.5 ng/mL (95% confidence interval, 9.0-17.3 ng/mL) in thrombocytopenic controls (n = 36, P < .0001), and 14.6 ng/mL (95% confidence interval, 7.9-27.1 ng/mL) in healthy subjects (n = 25, P = .002). In conclusion, coagulation-induced GPVI shedding via FXa down-regulates GPVI under procoagulant conditions. FXa inhibitors have an unexpected role in preventing GPVI down-regulation.

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Targeting platelet glycoprotein VI attenuates progressive ischemic brain damage before recanalization during middle cerebral artery occlusion in mice

Experimental Neurology ◽

10.1016/j.expneurol.2021.113804 ◽

2021 ◽

pp. 113804

Author(s):

Michael Bieber ◽

Michael K. Schuhmann ◽

Alexander M. Kollikowski ◽

David Stegner ◽

Bernhard Nieswandt ◽

...

Keyword(s):

Middle Cerebral Artery ◽

Middle Cerebral Artery Occlusion ◽

Brain Damage ◽

Cerebral Artery ◽

Artery Occlusion ◽

Platelet Glycoprotein ◽

Ischemic Brain Damage ◽

Ischemic Brain ◽

Glycoprotein Vi ◽

Cerebral Artery Occlusion

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Platelet glycoprotein VI and C-type lectin-like receptor 2 deficiency accelerates wound healing by impairing vascular integrity in mice

Haematologica ◽

10.3324/haematol.2018.208363 ◽

2019 ◽

Vol 104 (8) ◽

pp. 1648-1660 ◽

Cited By ~ 5

Author(s):

Surasak Wichaiyo ◽

Sian Lax ◽

Samantha J. Montague ◽

Zhi Li ◽

Beata Grygielska ◽

...

Keyword(s):

Wound Healing ◽

Platelet Glycoprotein ◽

Vascular Integrity ◽

Glycoprotein Vi

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D-Dimer and Fibrin Degradation Products Impair Platelet Signaling: Plasma D-Dimer Is a Predictor and Mediator of Platelet Dysfunction During Trauma

The Journal of Applied Laboratory Medicine ◽

10.1093/jalm/jfaa047 ◽

2020 ◽

Vol 5 (6) ◽

pp. 1253-1264

Author(s):

Christopher C Verni ◽

Antonio Davila ◽

Carrie A Sims ◽

Scott L Diamond

Keyword(s):

Degradation Products ◽

Calcium Mobilization ◽

Factor Xiiia ◽

Platelet Glycoprotein ◽

Trauma Patients ◽

Platelet Dysfunction ◽

Soluble Fibrin ◽

Glycoprotein Vi ◽

Fibrin Degradation Products ◽

D Dimer

Abstract Background Platelet dysfunction often accompanies trauma-induced coagulopathy. Because soluble fibrin impairs platelet glycoprotein VI (GPVI) signaling and platelets of trauma patients can display impaired calcium mobilization, we explored the role of fibrinolysis on platelet dysfunction during trauma. Methods Convulxin-induced GPVI calcium mobilization was investigated in healthy platelet-rich plasma (PRP) pretreated with thrombin and tissue plasminogen activator (tPA). Blood samples from healthy participants (n = 7) and trauma patients (n = 22) were tested for platelet calcium mobilization, plasma D-dimer, platelet D-dimer binding (via flow cytometry), and platelet lumi-aggregometry. Results For healthy platelets, maximal platelet dysfunction was observed when cross-linked soluble fibrin (no tPA) or cross-linked fibrin degradation products (FDPs) were generated in suspension before convulxin stimulation. Lack of fibrin polymerization (inhibited by Gly-Pro-Arg-Pro [GPRP]) or lack of factor XIIIa cross-linking (T101-inhibited) restored GPVI signaling, whereas non–cross-linked FDPs only partially blocked signaling induced by convulxin. In addition, D-dimer added to healthy PRP impaired platelet aggregation and dense granule release induced by various agonists. Plasma D-dimer level was strongly correlated (R = 0.8236) with platelet dysfunction as measured by platelet calcium mobilization induced with various agonists. By 48 to 120 h after trauma, plasma D-dimer levels declined, and platelet function increased significantly but not to healthy levels. Trauma platelets displayed elevated D-dimer binding that was only partially reduced by αIIbβ3-inhibitor GR144053. After 60-minute incubation, washed healthy platelets resuspended in plasma from trauma patients captured approximately 10 000 D-dimer equivalents per platelet. Conclusions During trauma, D-dimer and FDPs inhibit platelets, potentially via GPVI and integrin αIIbβ3 engagement, contributing to a fibrinolysis-dependent platelet loss-of-function phenotype.

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Establishment of a flow cytometric assay for determination of human platelet glycoprotein VI based on a mouse polyclonal antibody

Journal of Clinical Laboratory Analysis ◽

10.1002/jcla.20150 ◽

2006 ◽

Vol 20 (6) ◽

pp. 250-254 ◽

Cited By ~ 4

Author(s):

Chen-xue Qu ◽

Jian-zhong Wang ◽

Wen-hui Wan ◽

Chuan-bao Li ◽

Shu-lan Wu

Keyword(s):

Polyclonal Antibody ◽

Human Platelet ◽

Platelet Glycoprotein ◽

Flow Cytometric Assay ◽

Glycoprotein Vi ◽

Flow Cytometric

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Study of a humanized inhibitory anti-platelet glycoprotein VI phage antibody from a phage antibody library

Hematology ◽

10.1179/1607845415y.0000000047 ◽

2015 ◽

Vol 21 (1) ◽

pp. 60-67

Author(s):

Qinghong Liu ◽

Chunmei Zhang ◽

Lingjia Yu ◽

Yongyu Shi ◽

Liping Zhang ◽

...

Keyword(s):

Platelet Glycoprotein ◽

Antibody Library ◽

Phage Antibody ◽

Glycoprotein Vi ◽

Phage Antibody Library

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Platelet glycoprotein VI (GPVI) for early identification of acute coronary syndrome in patients with chest pain

Thrombosis Research ◽

10.1016/j.thromres.2010.01.005 ◽

2010 ◽

Vol 125 (5) ◽

pp. e184-e189 ◽

Cited By ~ 29

Author(s):

Boris Bigalke ◽

Michael Haap ◽

Konstantinos Stellos ◽

Tobias Geisler ◽

Peter Seizer ◽

...

Keyword(s):

Acute Coronary Syndrome ◽

Chest Pain ◽

Early Identification ◽

Platelet Glycoprotein ◽

Glycoprotein Vi ◽

Coronary Syndrome

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Platelet Glycoprotein VI Haplotypes and the Presentation of Paediatric Sepsis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1676794 ◽

2018 ◽

Vol 119 (03) ◽

pp. 431-438 ◽

Cited By ~ 2

Author(s):

Ahmed Asfari ◽

Judith Dent ◽

Adam Corken ◽

Danielle Herington ◽

Vamsikrishna Kaliki ◽

...

Keyword(s):

Inflammatory Responses ◽

Blood Platelets ◽

In Vitro Release ◽

Membrane Receptor ◽

Disease Classification ◽

Platelet Glycoprotein ◽

Collagen Membrane ◽

Healthy Individuals ◽

Glycoprotein Vi ◽

The Impact

AbstractSepsis triggers a complex series of pathophysiologic events involving inflammatory responses and coagulation abnormalities. While circulating blood platelets are well-characterized for their contributions to coagulation, increasingly platelet-dependent effects on inflammation are being recognized. Here, we focus on the platelet membrane receptor, glycoprotein VI (GPVI), and its role in platelet microparticle (pMP) release. The GPVI receptor is a platelet-specific collagen membrane receptor that, upon ligand binding, facilitates the release of pMPs. As membrane-bound platelet fragments of less than 1 μm, pMPs are known to have both pro-inflammatory and pro-coagulant properties. Thus, pMPs are potentially impacting sepsis at multiple stages of the inflammatory response. Studies are presented documenting the impact of the most common GPVI haplotypes, GPVIa and GPVIb, on pMP levels and release in healthy individuals (n = 49). The GPVIa haplotype corresponds to an approximately twofold increase in circulating pMPs as a percentage of total microparticles in healthy individuals along with a heightened in vitro release of pMPs. Additionally, patients admitted to a paediatric intensive care unit (ICU) (n = 73) with an initial diagnosis of sepsis were recruited and their GPVI haplotypes determined. Septic patients of the GPVIa haplotype (n = 59) were statistically more likely to present with a diagnosis of severe sepsis or septic shock, as compared with GPVIb individuals (n = 14). Independent disease classification via PELOD-2 and Pediatric Risk of Mortality III scores confirmed individuals with the GPVIa haplotype were more likely to have significant organ failure. Thus, GPVI haplotypes influence pMP levels in the circulation and are predictive of sepsis severity when presenting to the ICU.

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Sandwich Immunoassay for Soluble Glycoprotein VI in Patients with Symptomatic Coronary Artery Disease

Clinical Chemistry ◽

10.1373/clinchem.2010.158527 ◽

2011 ◽

Vol 57 (6) ◽

pp. 898-904 ◽

Cited By ~ 23

Author(s):

Boris Bigalke ◽

Oliver Pötz ◽

Elisabeth Kremmer ◽

Tobias Geisler ◽

Peter Seizer ◽

...

Keyword(s):

Subgroup Analysis ◽

Troponin I ◽

Early Stage ◽

Surface Expression ◽

Sandwich Immunoassay ◽

Platelet Glycoprotein ◽

Glycoprotein Vi ◽

Coronary Syndrome ◽

St Elevation ◽

Artery Disease

BACKGROUND Platelet glycoprotein VI (pGPVI) expression is increased in acute coronary syndrome (ACS), reflecting platelet activation. There is no reliable method available to measure pGPVI. Our aim was to develop a bead-based sandwich immunoassay to measure soluble GPVI (sGPVI). METHODS Based on antibodies for sGPVI developed earlier, we established and validated a bead-based sandwich immunoassay in 2438 consecutive patients with stable angina pectoris (SAP; n = 1371), non–ST-elevation myocardial infarction (NSTEMI; n = 724), and ST-elevation MI (STEMI; n = 343). In a subgroup (n = 1011), we measured surface expression of pGPVI using flow cytometry. RESULTS The assay revealed a working range of 8–500 ng/L. Intra- and interassay imprecision was <7% and <14%, respectively. Patients with NSTEMI and STEMI showed significantly lower mean sGPVI concentrations than patients with SAP [mean (SD), 8.4 (3.6) μg/L and 8.6 (4.1) μg/L vs 9.8 (4.8) μg/L; P = 0.002], whereas subgroup analysis revealed significantly enhanced pGPVI in NSTEMI (n = 276) and STEMI (n = 80) patients compared with SAP (n = 655) [mean fluorescence intensity (SD), 21.2 (8.1) and 19.8 (6.8) vs 18.5 (7.7); P = 0.002 and P = 0.018]. pGPVI and sGPVI were inversely correlated (r = −0.076; P = 0.023). Area under the ROC curve was 0.716, 95% CI 0.681–0.751, for sGPVI, distinguishing patients with SAP from those with ACS, and was superior (P = 0.044) to the curve of subgroup analysis for pGPVI (0.624, 95% CI 0.586–0.662). sGPVI (P = 0.023) and pGPVI (P = 0.028) had better association with the development of ACS than troponin I (P = 0.055) in the very early stage of disease, based on logistic regression analysis. CONCLUSIONS This sandwich immunoassay reliably measures sGPVI and may help to identify patients with ACS earlier than other laboratory markers.

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