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Research Article
Originally Published 14 January 2016
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Coagulation Factor XI Promotes Distal Platelet Activation and Single Platelet Consumption in the Bloodstream Under Shear Flow

Jevgenia Zilberman-Rudenko, Asako Itakura, Chantal P. Wiesenekker, Ralf Vetter, Coen Maas, David Gailani, Erik I. Tucker, András Gruber, Christoph Gerdes, and Owen J.T. McCartyAuthor Info & Affiliations
Arteriosclerosis, Thrombosis, and Vascular Biology
Volume 36, Number 3
https://doi.org/10.1161/ATVBAHA.115.307034
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Abstract

Objective—

Coagulation factor XI (FXI) has been shown to contribute to thrombus formation on collagen or tissue factor–coated surfaces in vitro and in vivo by enhancing thrombin generation. Whether the role of the intrinsic pathway of coagulation is restricted to the local site of thrombus formation is unknown. This study was aimed to determine whether FXI could promote both proximal and distal platelet activation and aggregate formation in the bloodstream.

Approach and Results—

Pharmacological blockade of FXI activation or thrombin activity in blood did not affect local platelet adhesion, yet reduced local platelet aggregation, thrombin localization, and fibrin formation on immobilized collagen and tissue factor under shear flow, ex vivo. Downstream of the thrombus formed on immobilized collagen or collagen and 10 pmol/L tissue factor, platelet CD62P expression, microaggregate formation, and progressive platelet consumption were significantly reduced in the presence of FXI function-blocking antibodies or a thrombin inhibitor in a shear rate– and time-dependent manner. In a non-human primate model of thrombus formation, we found that inhibition of FXI reduced single platelet consumption in the bloodstream distal to a site of thrombus formation.

Conclusions—

This study demonstrates that the FXI–thrombin axis contributes to distal platelet activation and procoagulant microaggregate formation in the blood flow downstream of the site of thrombus formation. Our data highlight FXI as a novel therapeutic target for inhibiting distal platelet consumption without affecting proximal platelet adhesion.

Introduction

Platelets and coagulation factors are 2 essential components of hemostasis. On vessel injury, resting platelets are immediately recruited to the exposed extracellular matrix under shear flow, followed by platelet adhesion and activation.1 Platelet activation triggers the surface expression of P-selectin (CD62P) from α-granules, and the conversion of integrin αIIbβ3 to its active conformation, potentiating homotypic aggregate formation via fibrinogen binding. In parallel, activation of the coagulation cascade leads to thrombin generation, which cleaves fibrinogen to fibrin to stabilize the hemostatic plug. Thrombin is also able to activate platelets through protease-activated receptors and thus accelerate the activation of both hemostatic components.
Coagulation factor XI (FXI) participates in the intrinsic pathway, whereby activated FXI (FXIa) triggers the downstream activation of factor IX (FIX), which in turn activates factor X (FX). FXa then converts prothrombin to thrombin. Thrombin can directly activate FXIa to perpetuate its own generation, thereby creating a procoagulant feedback loop of thrombin generation driven by FXI–thrombin axis.2–4 To date, however, it is not clear whether the FXI–thrombin axis facilitates platelet activation and consumption in blood flow under prothrombotic conditions.
The aim of this study was to define the role of the FXI–thrombin axis in promoting platelet activation and aggregation at the site of, and distal to, thrombus formation under shear flow. We show that inhibition of FXIIa activation of FXI or thrombin activity abrogated platelet CD62P expression and microaggregate formation under both venous and arterial shear flows downstream of the site of thrombus formation on collagen and 10 pmol/L tissue factor (TF). In vivo, inhibition of FXI also reduced single platelet consumption in the bloodstream distal to a site of thrombus formation. These results provide the first evidence of a role for FXI in mediating platelet activation and platelet aggregate formation downstream of the site of thrombus formation.

Materials and Methods

Materials and Methods are available in the online-only Data Supplement.

Results

Role of FXII and FXI in Clotting Times

Our initial experiments were designed to evaluate the anticoagulant activity of FXI function-blocking antibodies, FXII inhibitor (corn trypsin inhibitor [CTI]), and thrombin inhibitor (hirudin) in recalcified whole blood and platelet-poor plasma (Figure 1). Inhibition of FXI activation by FXIIa and FIX activation by FXIa with the function-blocking FXI antibody (FXI-Ab 1A6) nearly tripled the activated partial thromboplastin time in whole blood (47.8±5.6 s) to 126.9±15 s. Inhibition of FXI activation by FXIIa (FXI-Ab 14E11) or the neutralization of the FXIa active site (FXI-Ab 10C9) or inhibition of FXII activity (CTI) prolonged activated partial thromboplastin time to 98.3±12.2 s, 87.9±3.3 s, and 94.2±6.9 s, respectively (Figure 1A). As expected, none of the inhibitors, except for the direct thrombin inhibitor (hirudin), were able to prolong prothrombin time in whole blood (Figure 1D). Similar results were seen in activated partial thromboplastin time and prothrombin time assays using platelet-poor pooled human plasma (Figure 1B and 1E). Moreover, activated partial thromboplastin times were prolonged to 162.3±1.9 and 212.6±2.4 s using FXI- and FXII-immunodepleted plasmas, respectively (Figure 1C), whereas prothrombin times were slightly prolonged to 14.1±0.3 and 15.2±0.1 s, respectively (Figure 1F).
Figure 1. Role of coagulation factor (FX) II and FXI in clotting times. Recalcified whole blood (A and D), pooled human plasma (PPP; B and E) or coagulation factor–depleted plasma (C and F) was incubated with indicated FXI function-blocking antibody, FXII inhibitor (corn trypsin inhibitor [CTI]) or direct thrombin inhibitor (hirudin). Activated partial thromboplastin time (aPTT; A–C) or PT (D–F) was recorded as described in Methods in the online-only Data Supplement. * Significantly different, P<0.05, clotting time vs vehicle (veh; mean±SEM).

FXIa Activity Promotes Local Fibrin Formation Under Shear

We next studied the role of FXI activation in local platelet deposition and fibrin formation under physiologically relevant shear flow conditions. Robust platelet adhesion, aggregation, and fibrin formation were observed after the perfusion of recalcified whole blood over surfaces coated with collagen (Figure 2A and 2B). Both the rate and the extent of fibrin formation were enhanced on surfaces coated with collagen and TF (0.01–0.1 nmol/L), as visually recorded using differential interference contrast and fluorescence microscopy (Figure 2C and 2D; Figure IA and IB in the online-only Data Supplement). TF alone (0.01–0.1 nmol/L) yielded robust fibrin networks largely absent of platelets (Figure IA and IB in the online-only Data Supplement).
Figure 2. Coagulation factor (FX) Ia activity promotes local fibrin formation under shear. Recalcified whole blood was perfused over collagen (A and B) or collagen and 0.1 nmol/L tissue factor (TF; C and D) for indicated times at a shear rate of 300 s−1. Images of local thrombi formed at each time point in the presence of vehicle control, 50 μg/mL 1A6 or 40 μg/mL corn trypsin inhibitor (CTI) were recorded using differential interference contrast (A and C) or fluorescent light microscopy (B and D) after staining for fibrin (blue) and P-selectin (green). In parallel experiments, thrombi were lysed and immunoblotted for the fibrin-degradation product, D-dimer, thrombin, and the platelet surface receptor, CD41a (E and F).
Inhibition of FXI activation by FXIIa and FIX activation by FXIa with FXI-Ab 1A6, or inhibition of FXIIa activity with CTI, decreased fibrin formation on collagen or surfaces coated with collagen and 0.01 nmol/L TF or TF alone (Figure 2A and 2B; Figure IA and IB in the online-only Data Supplement). Hirudin prevented fibrin formation on all surfaces, whereas CTI had no effect on surfaces coated with collagen and 0.1 nmol/L (Figure 2C and 2D).
These results were confirmed by analyzing the degree of fibrin formation and platelet deposition by Western blotting after clot lysis with plasmin for the fibrin-degradation product, D-dimer, and the CD41a platelet surface marker (Figure 2E and 2F; Figure IC in the online-only Data Supplement). Interestingly, we were able to detect thrombin in local thrombus lysates, and found that the increasing levels of clot-bound thrombin correlated with D-dimer levels. We found that the inhibition of FXI activation by FXIIa with 14E11 reduced fibrin formation on collagen alone, whereas neither 14E11 nor the FXIa active site domain-neutralizing antibody, 10C9, affected fibrin formation on surfaces coated with collagen and 0.1 nmol/L TF (Figure IC in the online-only Data Supplement). Control experiments using the thrombin inhibitor, hirudin, were shown to eliminate fibrin formation and the presence of clot-bound thrombin on all surfaces.

Propagation of Distal Platelet Activation and Single Platelet Consumption Under Shear in Flow

We next designed a platform to determine whether local fibrin formation and thrombin generation at sites of thrombus formation promoted distal platelet activation and aggregate formation in the bloodstream. As shown in Figure 3A, a set length of tubing was added downstream of the chamber to allow platelets to react in flow for a set time (residence time) before being collected at 1-minute intervals into tubes containing PPACK (a serine protease inhibitor, Phe-Pro-Arg-chloromethylketone) and sodium citrate. Distal single platelet consumption (reduction of single platelet population in the bloodstream), platelet activation (CD62P expression), and platelet microaggregate formation in solution (CD41a/CD31 high positive) were quantified using flow cytometry (Figure 3B). In parallel, untreated upstream samples were collected and analyzed to define the baseline parameters (time = 0 minute) or stimulated with thrombin receptor activator peptide-6 to induce maximal platelet activation or microaggregate formation as a positive control (mean±SEM: 94.3±0.3% P-selectin activation, 47.6±2.4% microaggregate formation, and 77.2±3.6% single platelet consumption).
Figure 3. Propagation of distal platelet activation and single platelet consumption (SPC) under shear in flow. Recalcified whole blood was perfused through a 200-mm chamber (coated with either BSA or 150 μg/mL collagen+0.1 nmol/L tissue factor [TF]) before being collected downstream after indicated residence time in flow (A). Downstream samples were collected into a reaction quenching solution at 1-min intervals, immunostained and evaluated by fluorescence-activated cell sorter flow cytometry for percent platelet activation (CD41a+/CD62P+ events), platelet microaggregate formation (high fluorescence intensity CD41a+/CD31+ events) and single platelet consumption (SPC; loss of single platelet population gate on forward scatter [FSC] by side scatter [SSC]). Representative raw FACS scatter plots (B) and quantification (C) for at least 3 experiments are reported (mean±SEM).
Our results show that platelet P-selectin expression, microaggregate formation, and single platelet consumption increased as a function of residence time in whole blood samples downstream of chambers coated with collagen and 0.1 nmol/L TF (Figure 3C). In contrast, an increase in platelet activation, microaggregate formation, or single platelet consumption was not observed downstream of BSA-coated chambers.
At a set residence time of 30 s, we observed an increase in platelet activation, microaggregate formation, and single platelet consumption as a function of perfusion times downstream of chambers coated with collagen (Figure 4A). The inclusion of 0.01 to 1.0 nmol/L TF with collagen coatings significantly increased both the rate and the extent of platelet activation and microaggregate formation. It should be noted that the presence of TF dramatically increased the rate of single platelet consumption, resulting in over a 95% loss of single platelets by 8, 4, and 2 minutes for 0.01, 0.1, and 1 nmol/L TF, respectively, leading to grossly visible insoluble clot formation in flow in the distal samples. A drop in the percentage of activated platelets and microaggregates was observed at these time points, reflective of the consumption of single platelets and microaggregates into downstream clots. Inhibition of platelet glycoprotein IIb/IIIa homodimer formation with eptifibatide increased circulating levels of single activated platelets and decreased microaggregate formation and single platelet consumption downstream of collagen-coated chambers. Similarly, the prevention of clot formation in solution downstream of collagen with 0.1 nmol/L TF-coated chambers with eptifibatide resulted in a continued increase in circulating activated platelet levels beyond 4 minutes and attenuated both microaggregate formation and single platelet consumption, presumably sustained by fibrin agglutination (Figure 4B).
Figure 4. Presence of collagen and tissue factor (TF) promotes distal platelet consumption. Recalcified whole blood was perfused through a 200-mm chamber (coated with either BSA, collagen or collagen+0.01–1.0 nmol/L TF) and allowed to react in flow for 30 s (residence time) before being collected into a reaction quenching solution at 1-min intervals. Quantification of platelet activation, microaggregate formation, and single platelet consumption (SPC) using fluorescence-activated cell sorter (A) for at least 5 experiments are reported (mean±SEM). In parallel experiments, whole blood was pretreated with a glycoprotein IIb/IIIa inhibitor, eptifibatide (B).

FXIa Activity Promotes Distal Platelet Activation and Consumption in the Presence of Collagen and TF

To examine the role of FXI activation in promoting distal platelet activation, whole blood was pretreated with the function-blocking FXI antibodies (1A6, 14E11, or 10C9), FXIIa inhibitor (CTI), or the thrombin inhibitor (hirudin) before perfusion through flow chambers coated with collagen, TF, a combination of collagen and TF (0.01–0.1 nmol/L), fibrinogen, thrombin, or von Willebrand factor. Distal samples were collected downstream after 30 s of residence time. We found that collagen, whether alone or in combination with TF, promoted the greatest degree of distal platelet activation and consumption when compared with TF alone, fibrinogen, thrombin, or von Willebrand factor (Figure 5; Figure III in the online-only Data Supplement). Our results show that the inhibition of FXIIa activation of FXI, FXIa activation of FIX and FXIa activity with 14E11, 1A6, and 10C9, respectively, or FXIIa activity with CTI eliminated platelet activation, microaggregate formation, and single platelet consumption downstream of collagen-coated chambers (Figure 5A). Exposure of blood to collagen in combination with increasing concentrations of TF drastically accelerated the rate and the extent of distal platelet activation, microaggregate formation, and consumption (Figure 5B and 5C). In contrast to collagen alone, only the FXI inhibitor 1A6 attenuated the rate of platelet consumption in the presence of higher levels TF (0.1 nmol/L), whereas both 1A6 and CTI were able to significantly reduce the rate of platelet consumption in the presence of lower levels of TF (0.01 nmol/L). Hirudin dramatically reduced the degree of distal platelet activation, microaggregate formation, and single platelet consumption regardless of local TF concentration. A similar mechanism was observed when the shear rate was increased to 1000 s−1 (Figure IIB in the online-only Data Supplement). These results suggest a role for the contact activation pathway in the initial amplification of thrombin generation downstream of sites of thrombus formation under flow.
Figure 5. Activated coagulation factor XI (FXIa) activity promotes distal platelet activation and consumption in the presence of collagen and low levels of tissue factor (TF). Recalcified whole blood pretreated with either vehicle (veh), 1A6, 14E11, 10C9, corn trypsin inhibitor (CTI), or hirudin was perfused over chambers coated with collagen, collagen+0.01 to 0.1 nmol/L TF, or 0.01 to 0.1 nmol/L TF alone at shear rate of 300 s−1. Samples were collected downstream of the chamber; distal microaggregate formation and single platelet consumption were assessed by fluorescence-activated cell sorter (A–E). Results (mean±SEM) from at least 4 experiments.

Protection of 1A6-Treated Baboons From Collagen-Initiated Distal Single Platelet Consumption

To examine the role of FXI activation in promoting distal platelet consumption in non-human primate baboon model, blood was collected distally from acutely introduced collagen-coated or control BSA-coated grafts in animals with chronic high flow arteriovenous shunts (Figure 6A). In line with the results shown in Figure 4A, exposure of blood to collagen in vivo accelerated the rate and the extent of distal single platelet consumption when compared with BSA controls. Our data demonstrate that the inhibition of FXI activity with 1A6 treatment reduced distal single platelet consumption at 20 minutes of perfusion by 50% (P=0.0180; n=6; Figure 6B). Taken together with our previous studies demonstrating that the inhibition of FXI prevented occlusion of collagen-coated grafts in a non-human primate model of thrombosis without increasing bleeding times, our data provide rationale for the development of anti-FXI therapeutics for the prevention of thrombotic distal complications.
Figure 6. Protection of 1A6-treated baboons from collagen-initiated distal single platelet consumption. Four-millimeter internal diameter expanded polytetrafluoroethylene (ePTFE) vascular graft coated with collagen was deployed into a chronic high flow AV shunt in healthy baboons. In parallel, control experiments were performed with tubing alone. Samples were drawn from the intraluminal coagulation marker concentration boundary layer by a syringe pump 1 cm downstream from acutely developing thrombi. One millimole per liter of the serine protease inhibitor Phe-Pro-Arg-chloromethylketone (PPACK) was infused at one fifth of the sample extraction rate 3 mm proximal to the sample port to prevent the sample port from occluding during the 1-h study. Blood flow through the graft was maintained at a fixed rate of 100 mL/min for the entirety of each study by proximal clamping (A). Quantification of the 6 separate animal experiments for each treatment (mean±SEM) is reported (B). Significant rise in percent single platelet consumption immediately distal to collagen-coated ePTFE was seen between 10 and 20 min of perfusion in control animals (*P=0.0283; n=6). 1A6-treated baboons maintained same single platelet levels at 20 min as at 10 min of perfusion (P=0.9530; n=6) significantly different from control at 20 min of perfusion (**P=0.0180; n=6).

Discussion

Coagulation FXI is an intrinsic pathway enzyme with an elusive role in normal hemostasis and mounting evidence for roles in thrombosis. Clinically, FXI deficiency is associated with only mild and injury-related bleeding, whereas elevated levels of FXI are associated with an increased risk for thrombotic complications.5–7 Patients deficient in the other members of the contact pathway, namely FXII and prekallikrein, do not exhibit bleeding complications, suggesting that FXI may play a role in hemostasis through feedback activation by thrombin.8–11 Moreover, activated FXI is able to activate FIX, FX, FV, and FVIII, bind platelets, and inhibit TF pathway inhibitor.12–15 FXI, therefore, acts to amplify thrombin via multiple pathways, providing rationale for the inhibition of FXI-mediated thrombin generation as an antithrombotic therapy design. For instance, a phase 2 clinical trial reducing FXI levels using FXI-antisense oligonucleotide demonstrated decreased incidence of deep venous thrombosis after knee replacement surgery. Although the study showed that the reduction of FXI levels prevented venous thrombosis, translational approaches targeted at FXI may sacrifice the hemostatic function of FXI, increasing the risk of bleeding.16,17 Thus, a better understanding of the role of FXI in thrombosis and hemostasis is required for the rational development of agents that target specific enzymatic functions of FXI, balancing safety with efficacy.
The biophysics of thrombus formation at a site of vascular injury has been well described,18–20 in which blood flow dictates the transport kinetics of blood cells and coagulation factors to the site of injury, and thrombin generation is rate limited by the assembly and sequential activation of coagulation factors on the surface or activated platelets. Thus, the Damköhler number (Da), which is the ratio of the rate of reaction to the rate of transport,21 is high (Da>1). In contrast, within the bloodstream, the kinetics of platelet activation and thrombin generation are diffusion limited, as platelets in the bloodstream experience limited relative blood flow, as cells in suspension are transported by viscous forces within the bloodstream, resulting in a low Da (<1). Our study demonstrates that FXI plays a differential role in promoting thrombin generation, platelet activation, and aggregate formation in the bloodstream (diffusion-limited regime) relative to the site of thrombus formation (transport-limited regime).
Previously, we have demonstrated that the inhibition of FXI activation by FXIIa is protective in a non-human primate model of local thrombus formation specifically because of a decrease in local thrombin generation and fibrin formation.22–24 However, the mechanism by which the FXIa–thrombin axis may contribute to the formation of platelet aggregates in flowing blood and distal microvascular occlusions under proximal procoagulant conditions has not been explored. In this study, we investigated downstream changes in platelets in whole blood following passage through collagen- or collagen and TF-coated flow chambers. Our results demonstrate that local thrombus formation on immobilized collagen and TF potentiated platelet activation in the bloodstream, resulting in the rapid formation of platelet aggregates in the bloodstream, which may hold potential to occlude downstream vessels. This process of distal platelet activation was directly dependent on thrombin activity. Inhibition of FIX activation by FXIa with the FXI-Ab 1A6 was protective against distal single platelet consumption in the bloodstream both in vitro and in vivo, providing an additional role for FXI in thrombotic complications.
It has been established that the health of microvessels plays an important role in maintaining unobstructed blood flow to organs. Aging vessels are stiffer and more tortuous because of many factors including atherosclerosis plaque buildup, hypertension-driven vessel wall remodeling, smoking, and diabetes mellitus, which predispose them to aberrant blood flow, platelet activation, and thrombosis.25 The physical biology of the microvasculature promotes increased platelet–platelet and platelet–endothelial cell interactions.26,27 In addition, the reduced flow rates within venules serve to increase the residence time of circulating platelets within these vascular beds. In patients, introduction of a vascular injury, such as a surgical incision during a joint replacement followed by stasis because of patient immobility post operation, may result in a local burst of thrombin generation.28,29 Under these conditions, our findings would suggest that FXI-dependent thrombin amplification and activation of platelets potentiate platelet microaggregate formation, which may then occlude the microvascular networks.
In summary, this study demonstrates that the FXI axis plays a key role in distal platelet activation and microaggregate formation in solution downstream of thrombus formation under both venous and arterial shear flow. In addition to its anticoagulant role, pharmacological targeting of FXI might be able to regulate platelet function and therefore prevent platelet-driven amplification of circulating thrombi formation in prothrombotic conditions involving direct contact pathway agonists and widespread vascular injury.

Acknowledgments

We thank C. Puy, S. Baker-Groberg, J. Pang, and K. Rees for insightful comments and technical assistance.

Significance

Hemostasis is an active process between plasma and blood cells, resulting in thrombin generation, platelet activation, and fibrin formation to generate a hemostatic plug that staunches blood loss after vessel injury. Although the enzymatic reactions that mediate hemostasis are orchestrated outside the lumen of the blood vessel, thrombosis results from clot formation within the blood vessel. The events that support hemostasis versus thrombosis are distinct, in part, because of the rheology of blood flow that differentially distributes blood components inside and outside blood vessels. We developed an ex vivo flow model to mimic a local site of vascular injury in combination with the downstream collection of blood samples to allow for the analysis of distal platelet activation, aggregation, and single platelet consumption in the bloodstream. Our results provide evidence that coagulation factor XI plays a role in mediating distal platelet activation and aggregate formation downstream of the site of primary thrombus formation.

Footnote

Nonstandard Abbreviations and Acronyms

CTI
corn trypsin inhibitor
FXI
coagulation factor XI
FXIa
activated coagulation factor XI
FXII
coagulation factor XII
TF
tissue factor

Supplemental Material

File (atvb_atvb-2015-307034d_supp1.pdf)
File (atvb_atvb-2015-307034d_supp2.pdf)

References

1.
Andrews RK, Berndt MC. Platelet physiology and thrombosis. Thromb Res. 2004;114:447–453. doi: 10.1016/j.thromres.2004.07.020.
Crossref
PubMed
Google Scholar
2.
Oliver JA, Monroe DM, Roberts HR, Hoffman M. Thrombin activates factor XI on activated platelets in the absence of factor XII. Arterioscler Thromb Vasc Biol. 1999;19:170–177.
Crossref
PubMed
Google Scholar
3.
Kravtsov DV, Matafonov A, Tucker EI, Sun MF, Walsh PN, Gruber A, Gailani D. Factor XI contributes to thrombin generation in the absence of factor XII. Blood. 2009;114:452–458. doi: 10.1182/blood-2009-02-203604.
Crossref
PubMed
Google Scholar
4.
Maas C, Meijers JC, Marquart JA, Bakhtiari K, Weeterings C, de Groot PG, Urbanus RT. Activated factor V is a cofactor for the activation of factor XI by thrombin in plasma. Proc Natl Acad Sci U S A. 2010;107:9083–9087. doi: 10.1073/pnas.1004741107.
Crossref
PubMed
Google Scholar
5.
Salomon O, Steinberg DM, Seligshon U. Variable bleeding manifestations characterize different types of surgery in patients with severe factor XI deficiency enabling parsimonious use of replacement therapy. Haemophilia. 2006;12:490–493. doi: 10.1111/j.1365-2516.2006.01304.x.
Crossref
PubMed
Google Scholar
6.
Meijers JC, Tekelenburg WL, Bouma BN, Bertina RM, Rosendaal FR. High levels of coagulation factor XI as a risk factor for venous thrombosis. N Engl J Med. 2000;342:696–701. doi: 10.1056/NEJM200003093421004.
Crossref
PubMed
Google Scholar
7.
Lavigne G, Mercier E, Queré I, Dauzat M, Gris JC. Thrombophilic families with inheritably associated high levels of coagulation factors VIII, IX and XI. J Thromb Haemost. 2003;1:2134–2139.
Crossref
PubMed
Google Scholar
8.
Gailani D, Renné T. The intrinsic pathway of coagulation: a target for treating thromboembolic disease? J Thromb Haemost. 2007;5:1106–1112. doi: 10.1111/j.1538-7836.2007.02446.x.
Crossref
PubMed
Google Scholar
9.
Renné T, Gailani D. Role of Factor XII in hemostasis and thrombosis: clinical implications. Expert Rev Cardiovasc Ther. 2007;5:733–741. doi: 10.1586/14779072.5.4.733.
Crossref
PubMed
Google Scholar
10.
Naito K, Fujikawa K. Activation of human blood coagulation factor XI independent of factor XII. Factor XI is activated by thrombin and factor XIa in the presence of negatively charged surfaces. J Biol Chem. 1991;266:7353–7358.
Crossref
PubMed
Google Scholar
11.
Gailani D, Broze GJ. Factor XI activation in a revised model of blood coagulation. Science. 1991;253:909–912.
Crossref
PubMed
Google Scholar
12.
Matafonov A, Cheng Q, Geng Y, Verhamme IM, Umunakwe O, Tucker EI, Sun MF, Serebrov V, Gruber A, Gailani D. Evidence for factor IX-independent roles for factor XIa in blood coagulation. J Thromb Haemost. 2013;11:2118–2127. doi: 10.1111/jth.12435.
Crossref
PubMed
Google Scholar
13.
Whelihan MF, Orfeo T, Gissel MT, Mann KG. Coagulation procofactor activation by factor XIa. J Thromb Haemost. 2010;8:1532–1539. doi: 10.1111/j.1538-7836.2010.03899.x.
Crossref
PubMed
Google Scholar
14.
White-Adams TC, Berny MA, Tucker EI, Gertz JM, Gailani D, Urbanus RT, de Groot PG, Gruber A, McCarty OJ. Identification of coagulation factor XI as a ligand for platelet apolipoprotein E receptor 2 (ApoER2). Arterioscler Thromb Vasc Biol. 2009;29:1602–1607. doi: 10.1161/ATVBAHA.109.187393.
Crossref
PubMed
Google Scholar
15.
Puy C, Tucker EI, Matafonov A, Cheng Q, Zientek KD, Gailani D, Gruber A, McCarty OJ. Activated factor XI increases the procoagulant activity of the extrinsic pathway by inactivating tissue factor pathway inhibitor. Blood. 2015;125:1488–1496. doi: 10.1182/blood-2014-10-604587.
Crossref
PubMed
Google Scholar
16.
Zhang H, Löwenberg EC, Crosby JR, MacLeod AR, Zhao C, Gao D, Black C, Revenko AS, Meijers JC, Stroes ES, Levi M, Monia BP. Inhibition of the intrinsic coagulation pathway factor XI by antisense oligonucleotides: a novel antithrombotic strategy with lowered bleeding risk. Blood. 2010;116:4684–4692. doi: 10.1182/blood-2010-04-277798.
Crossref
PubMed
Google Scholar
17.
Büller HR, Bethune C, Bhanot S, Gailani D, Monia BP, Raskob GE, Segers A, Verhamme P, Weitz JI; FXI-ASO TKA Investigators. Factor XI antisense oligonucleotide for prevention of venous thrombosis. N Engl J Med. 2015;372:232–240. doi: 10.1056/NEJMoa1405760.
Crossref
PubMed
Google Scholar
18.
Colace TV, Tormoen GW, McCarty OJ, Diamond SL. Microfluidics and coagulation biology. Annu Rev Biomed Eng. 2013;15:283–303. doi: 10.1146/annurev-bioeng-071812-152406.
Crossref
PubMed
Google Scholar
19.
Stalker TJ, Welsh JD, Tomaiuolo M, Wu J, Colace TV, Diamond SL, Brass LF. A systems approach to hemostasis: 3. Thrombus consolidation regulates intrathrombus solute transport and local thrombin activity. Blood. 2014;124:1824–1831. doi: 10.1182/blood-2014-01-550319.
Crossref
PubMed
Google Scholar
20.
Tomaiuolo M, Stalker TJ, Welsh JD, Diamond SL, Sinno T, Brass LF. A systems approach to hemostasis: 2. Computational analysis of molecular transport in the thrombus microenvironment. Blood. 2014;124:1816–1823. doi: 10.1182/blood-2014-01-550343.
Crossref
PubMed
Google Scholar
21.
McCarty OJT, Ku D, Sugimoto M, King MR, Cosemans JMEM, Neeves KB. Dimensional analysis and scaling relevant to flow models of thrombus formation [Accepted Article; published online ahead of print December 29, 2015]. J Thromb Haemost. doi: 10.1111/jth.13241. http://onlinelibrary.wiley.com/doi/10.1111/jth.13241/abstract.
Crossref
Google Scholar
22.
Cheng Q, Tucker EI, Pine MS, Sisler I, Matafonov A, Sun MF, White-Adams TC, Smith SA, Hanson SR, McCarty OJ, Renné T, Gruber A, Gailani D. A role for factor XIIa-mediated factor XI activation in thrombus formation in vivo. Blood. 2010;116:3981–3989. doi: 10.1182/blood-2010-02-270918.
Crossref
PubMed
Google Scholar
23.
Tucker EI, Marzec UM, White TC, Hurst S, Rugonyi S, McCarty OJ, Gailani D, Gruber A, Hanson SR. Prevention of vascular graft occlusion and thrombus-associated thrombin generation by inhibition of factor XI. Blood. 2009;113:936–944. doi: 10.1182/blood-2008-06-163675.
Crossref
PubMed
Google Scholar
24.
Leung PY, Hurst S, Berny-Lang MA, Verbout NG, Gailani D, Tucker EI, Wang RK, McCarty OJ, Gruber A. Inhibition of Factor XII-Mediated Activation of Factor XI Provides Protection Against Experimental Acute Ischemic Stroke in Mice. Transl Stroke Res. 2012;3:381–389. doi: 10.1007/s12975-012-0186-5.
Crossref
PubMed
Google Scholar
25.
Chesnutt JK, Han HC. Tortuosity triggers platelet activation and thrombus formation in microvessels. J Biomech Eng. 2011;133:121004. doi: 10.1115/1.4005478.
Crossref
PubMed
Google Scholar
26.
Zhang JN, Bergeron AL, Yu Q, Sun C, McIntire LV, López JA, Dong JF. Platelet aggregation and activation under complex patterns of shear stress. Thromb Haemost. 2002;88:817–821. doi: 10.1267/th02110817.
Crossref
PubMed
Google Scholar
27.
Casa LD, Ku DN. Geometric design of microfluidic chambers: platelet adhesion versus accumulation. Biomed Microdevices. 2014;16:115–126. doi: 10.1007/s10544-013-9811-7.
Crossref
PubMed
Google Scholar
28.
Wong RK, Sleep JR, Visner AJ, et al. Thrombography reveals thrombin generation potential continues to deteriorate following cardiopulmonary bypass surgery despite adequate hemostasis. J Extra Corpor Technol. 2011;43(1):19–25.
Crossref
PubMed
Google Scholar
29.
Shen F, Kastrup CJ, Liu Y, Ismagilov RF. Threshold response of initiation of blood coagulation by tissue factor in patterned microfluidic capillaries is controlled by shear rate. Arterioscler Thromb Vasc Biol. 2008;28:2035–2041. doi: 10.1161/ATVBAHA.108.173930.
Crossref
PubMed
Google Scholar

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Go to Arteriosclerosis, Thrombosis, and Vascular Biology
Go to Arteriosclerosis, Thrombosis, and Vascular Biology

Scanning electron microscopy combined with elemental analysis (orange for calcium) detects extracellular vesicles in calcified human tissue. (See pages 525–533.)

Arteriosclerosis, Thrombosis, and Vascular Biology
Volume 36 • Number 3 • March 2016
Pages: 510 - 517
PubMed: 26769048

Copyright

© 2016 American Heart Association, Inc.

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History

Received: 2 January 2014
Accepted: 5 January 2016
Published online: 14 January 2016
Published in print: March 2016

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Keywords

  1. blood coagulation
  2. blood platelets
  3. factor XI
  4. hemodynamics
  5. platelet activation

Subjects

  1. Platelets
  2. Thrombosis

Authors

Affiliations

Jevgenia Zilberman-Rudenko
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Asako Itakura
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Chantal P. Wiesenekker
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Ralf Vetter
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Coen Maas
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
David Gailani
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Erik I. Tucker
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
András Gruber
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Christoph Gerdes
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author
Owen J.T. McCarty
From the Biomedical Engineering, School of Medicine (J.Z.-R., A.I., C.P.W., E.I.T., A.G., O.J.T.M.) and Division of Hematology (A.G., O.J.T.M.), Oregon Health & Science University, Portland; Pathology and Medicine, School of Medicine, Vanderbilt University, Nashville, TN (D.G.); Aronora Inc., Portland, OR (E.I.T., A.G.); Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands (C.P.W., C.M.); and Global Drug Discovery, Bayer Pharma AG, Wuppertal, Germany (A.I., R.V., C.G.).
View all articles by this author

Notes

The online-only Data Supplement is available with this article at http://atvb.ahajournals.org/lookup/suppl/doi:10.1161/ATVBAHA.115.307034/-/DC1.
Correspondence to Jevgenia Zilberman-Rudenko, BS, Department of Biomedical Engineering, Oregon Health & Science University, 3303 SW Bond Ave, Portland, OR 97239. E-mail [email protected]

Disclosures

A. Gruber, E.I. Tucker, and the Oregon Health & Science University have a significant financial interest in Aronora Inc., a company that may have a commercial interest in the results of this research. This potential conflict of interest has been reviewed and managed by the Oregon Health & Science University Conflict of Interest in Research Committee. C. Gerdes and R. Vetter are employees of Bayer Pharma AG. The other authors report no conflicts.

Sources of Funding

This work was supported by grants from the National Institutes of Health (R01HL101972, R01GM116184 and R01HL047014), an Oregon Clinical and Translational Research Institute grant (UL1TR000128) and the Oregon Health & Science University School of Medicine MD/PhD program. O.J.T. McCarty is an American Heart Association Established Investigator (13EIA12630000). A. Itakura is a Bayer International Fellow.

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    • Samantha A. Moellmer,
    • Cristina Puy,
    • Owen J. T. McCarty,
    Biology of factor XI, Blood, 143, 15, (1445-1454), (2024).https://doi.org/10.1182/blood.2023020719
    Crossref
    • Tia C.L. Kohs,
    • Helen H. Vu,
    • Kelley R. Jordan,
    • Iván Parra-Izquierdo,
    • Monica T. Hinds,
    • Joseph J. Shatzel,
    • Paul Kievit,
    • Terry K. Morgan,
    • Samuel Tassi Yunga,
    • Thuy T.M. Ngo,
    • Joseph E. Aslan,
    • Michael Wallisch,
    • Christina U. Lorentz,
    • Erik I. Tucker,
    • David Gailani,
    • Jonathan R. Lindner,
    • Cristina Puy,
    • Owen J.T. McCarty,
    Activation of coagulation FXI promotes endothelial inflammation and amplifies platelet activation in a nonhuman primate model of hyperlipidemia, Research and Practice in Thrombosis and Haemostasis, 8, 1, (102276), (2024).https://doi.org/10.1016/j.rpth.2023.102276
    Crossref
    • Géraldine Poenou,
    • Marco Heestermans,
    • Ludovic Lafaie,
    • Sandrine Accassat,
    • Nathalie Moulin,
    • Alexandre Rodière,
    • Bastien Petit,
    • Cécile Duvillard,
    • Patrick Mismetti,
    • Laurent Bertoletti,
    Inhibition of Factor XI: A New Era in the Treatment of Venous Thromboembolism in Cancer Patients?, International Journal of Molecular Sciences, 24, 19, (14433), (2023).https://doi.org/10.3390/ijms241914433
    Crossref
    • Surasak Wichaiyo,
    • Warisara Parichatikanond,
    • Satsawat Visansirikul,
    • Nakkawee Saengklub,
    • Wipharak Rattanavipanon,
    Determination of the Potential Clinical Benefits of Small Molecule Factor XIa Inhibitors in Arterial Thrombosis, ACS Pharmacology & Translational Science, 6, 7, (970-981), (2023).https://doi.org/10.1021/acsptsci.3c00052
    Crossref
    • Yevhen Dzis,
    • Oleksandra Tomashevska,
    • Andriy Petrukh,
    RELATIONSHIPS BETWEEN LIPID PROFILE AND COMPLETE BLOOD CELL COUNT PARAMETERS, Acta Medica Leopoliensia, 28, 3-4, (97-113), (2022).https://doi.org/10.25040/aml2022.3-4.97
    Crossref
    • Reiner K. Mailer,
    • Thomas Renné,
    Commentary on “Pharmacological profile of asundexian, a novel, orally bioavailable inhibitor of factor XIa”: Small molecule factor XIa inhibitor asundexian allows for safer anticoagulation, Journal of Thrombosis and Haemostasis, 20, 6, (1309-1311), (2022).https://doi.org/10.1111/jth.15722
    Crossref
    • Hari Hara Sudhan Lakshmanan,
    • Aldrich Estonilo,
    • Stéphanie E. Reitsma,
    • Alexander R. Melrose,
    • Jayaram Subramanian,
    • Tony J. Zheng,
    • Jeevan Maddala,
    • Erik I. Tucker,
    • David Gailani,
    • Owen J.T. McCarty,
    • Patrick L. Jurney,
    • Cristina Puy,
    Revised model of the tissue factor pathway of thrombin generation: Role of the feedback activation of FXI, Journal of Thrombosis and Haemostasis, 20, 6, (1350-1363), (2022).https://doi.org/10.1111/jth.15716
    Crossref
    • Mareike Döhrmann,
    • Stephanie Makhoul,
    • Kathrin Gross,
    • Manuela Krause,
    • Daniele Pillitteri,
    • Charis Auer,
    • Ulrich Walter,
    • Jens Lutz,
    • Ivo Volf,
    • Beate E. Kehrel,
    • Kerstin Jurk,
    CD36‐fibrin interaction propagates FXI‐dependent thrombin generation of human platelets, The FASEB Journal, 34, 7, (9337-9357), (2020).https://doi.org/10.1096/fj.201903189R
    Crossref
    • Sanne L. N. Brouns,
    • Johanna P. van Geffen,
    • Elena Campello,
    • Frauke Swieringa,
    • Luca Spiezia,
    • René van Oerle,
    • Isabella Provenzale,
    • Remco Verdoold,
    • Richard W. Farndale,
    • Kenneth J. Clemetson,
    • Henri M. H. Spronk,
    • Paola E. J. van der Meijden,
    • Rachel Cavill,
    • Marijke J. E. Kuijpers,
    • Elisabetta Castoldi,
    • Paolo Simioni,
    • Johan W. M. Heemskerk,
    Platelet-primed interactions of coagulation and anticoagulation pathways in flow-dependent thrombus formation, Scientific Reports, 10, 1, (2020).https://doi.org/10.1038/s41598-020-68438-9
    Crossref
    • Matthew Sorrells,
    • Keith B. Neeves,
    Flow-Based Coagulation and Fibrinolysis Assays, Trauma Induced Coagulopathy, (745-762), (2020).https://doi.org/10.1007/978-3-030-53606-0_44
    Crossref
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Coagulation Factor XI Promotes Distal Platelet Activation and Single Platelet Consumption in the Bloodstream Under Shear Flow
Arteriosclerosis, Thrombosis, and Vascular Biology
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