References of "Lecut, Christelle"
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See detailEfficacy of the RemoweLL cardiotomy reservoir for fat and leucocyte removal from shed mediastinal blood: a randomized controlled trial.
LAGNY, Marc-Gilbert ULg; GOTHOT, André ULg; HANS, Grégory ULg et al

in Perfusion (2016)

Efficacy of the RemoweLL cardiotomy reservoir for Fat and Leucocyte removal from shed mediastinal blood: a randomized controlled trial. ABSTRACT (176 words) Introduction Re-transfusion of lipid particles ... [more ▼]

Efficacy of the RemoweLL cardiotomy reservoir for Fat and Leucocyte removal from shed mediastinal blood: a randomized controlled trial. ABSTRACT (176 words) Introduction Re-transfusion of lipid particles and activated leucocytes with shed mediastinal blood (SMB) can aggravate cardiopulmonary bypass-associated inflammation and increase the embolic load. This study evaluated the fat and leucocyte removal capacity of the RemoweLL cardiotomy reservoir. Methods Forty-five patients undergoing elective on-pump cardiac surgery were randomly allocated to filtration of SMB using the RemoweLL or the Admiral cardiotomy reservoir. The primary outcome was the drop in leucocytes and lipid particles obtained with the two filters. The effect of the filters on other blood cells and inflammatory mediators such as myeloperoxidase (MPO) was also assessed. Results The RemoweLL cardiotomy filter removed 16.5 % of the leucocytes (P < 0.001) while no significant removal of leucocytes was observed with the Admiral (P = 0.48). The percentage reductions in lipid particles were similar in the two groups (26% vs 23 %, P = 0.2). Both filters similarly affected the level of MPO (P = 0.71). Discussion The RemoweLL filter more effectively removed leucocytes from SMB than the Admiral. It offered no advantage in term of lipid particle clearance. [less ▲]

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See detailCLEC-2 is required for the activation of mouseplatelets by bacterial DNA mimetics
Delierneux, Céline ULg; Hego, Alexandre ULg; LECUT, Christelle ULg et al

Conference (2015, June 22)

Background: Short nuclease-resistant phosphorothioate synthetic CpG motif-bearing oligonucleotides (CpG ODNs) mimicking bacterial DNA display potent immunostimulatory activity and are therefore being used ... [more ▼]

Background: Short nuclease-resistant phosphorothioate synthetic CpG motif-bearing oligonucleotides (CpG ODNs) mimicking bacterial DNA display potent immunostimulatory activity and are therefore being used in clinical trials as vaccine adjuvants. Cellular uptake and activation depends on the interaction of CpG ODNs with the C-type lectin receptor DEC-205 and subsequent stimulation of the Toll-like receptor 9 (TLR9) and myeloid differentiation primary response 88 (MyD88) signaling cascade. Platelets express TLR9, MyD88, and the C-type lectin-like receptor 2 (CLEC-2). However, the impacts of CpG ODNs on platelet function have been elusive. Aims: To evaluate whether CpG ODNs affect platelet activation and thrombus formation via CLEC-2 and TLR9. Methods: We incubated washed platelets or whole blood from TLR9-, MyD88- or CLEC-2- deficient mice with CpG ODNs. We performed platelet aggregometry, flow cytometric binding and platelet activation assays as well as signal transduction analyses. Thrombus formation and fibrin generation were also analyzed by intravital microscopy in mouse microcirculation upon intravenous injection of CpG ODNs. Results: We show that CpG ODNs bind on platelet surface and are internalized. They activate platelets and induce their aggregation. TLR9- or MyD88-deficient platelets aggregated normally in response to CpG ODN. Interestingly, platelets deficient for the C-type lectin receptor CLEC-2 were unable to capture and internalize CpG ODN. CLEC-2 deficiencyabolished CpG ODN-induced platelet activation and aggregation. CpG ODN stimulated CLEC-2 dependent tyrosine kinase pathway and Syk phosphorylation. In vivo, intravenously injected CpG ODN interacted with platelets adhered to laser injured arteriolar endothelia and promoted fibrin generation and thrombus growth. Conclusion: CLEC-2 mediates CpG ODN uptake and subsequent platelet activation, independently of TLR9, which may serve an important role in the interplay between platelets and immunity. [less ▲]

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See detailCLEC-2 is required for the activation of mouse platelets by bacterial DNA mimetics
Delierneux, Céline ULg; Hego, Alexandre ULg; LECUT, Christelle ULg et al

Conference (2015, June 22)

Aims: To evaluate whether CpG ODNs affect platelet activation and thrombus formation via CLEC-2 and TLR9. Methods: We incubated washed platelets or whole blood from TLR9-, MyD88- or CLEC-2- deficient mice ... [more ▼]

Aims: To evaluate whether CpG ODNs affect platelet activation and thrombus formation via CLEC-2 and TLR9. Methods: We incubated washed platelets or whole blood from TLR9-, MyD88- or CLEC-2- deficient mice with CpG ODNs. We performed platelet aggregometry, flow cytometric binding and platelet activation assays as well as signal transduction analyses. Thrombus formation and fibrin generation were also analyzed by intravital microscopy in mouse microcirculation upon intravenous injection of CpG ODNs. Results: We show that CpG ODNs bind on platelet surface and are internalized. They activate platelets and induce their aggregation. TLR9- or MyD88-deficient platelets aggregated normally in response to CpG ODN. Interestingly, platelets deficient for the C-type lectin receptor CLEC-2 were unable to capture and internalize CpG ODN. CLEC-2 deficiency abolished CpG ODN-induced platelet activation and aggregation. CpG ODN stimulated CLEC-2 dependent tyrosine kinase pathway and Syk phosphorylation. In vivo, intravenously injected CpG ODN interacted with platelets adhered to laser injured arteriolar endothelia and promoted fibrin generation and thrombus growth. Conclusion: CLEC-2 mediates CpG ODN uptake and subsequent platelet activation, independently of TLR9, which may serve an important role in the interplay between platelets and immunity. [less ▲]

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See detailQuelle place pour le test de génération de thrombine au sein du laboratoire de biologie clinique?
LECUT, Christelle ULg; PETERS, Pierre ULg; MASSION, Paul ULg et al

in Annales de Biologie Clinique (2015), 73(2), 137-149

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See detailReflections about the optimisation of the treatment of tendinopathies with PRP
Kaux, Jean-François ULg; Bouvard, Marc; LECUT, Christelle ULg et al

in Muscles, Ligaments and Tendons Journal (2015), 5(1 (eCollection 2015 Jan-Mar)), 1-4

Background: platelet-rich plasma (PRP) infiltration represents a recent therapy for chronic tendinopathies. However, in the literature, this treatment remains controversial. Purpose: we suggest some ideas ... [more ▼]

Background: platelet-rich plasma (PRP) infiltration represents a recent therapy for chronic tendinopathies. However, in the literature, this treatment remains controversial. Purpose: we suggest some ideas for improving this treatment. Methods: these suggestions were based on a review of published studies and our clinical experience. Conclusion: optimizing the technique for PRP collection is paramount. Different risk factors must be corrected before infiltration and chronic tendinopathies must be carefully selected. Finally, post-infiltration rehabilitation remains absolutely critical. Standardization of the use of PRP remains necessary in order to optimize the results. [less ▲]

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See detailDUSP3 Phosphatase Deficiency or Inhibition Limit Platelet Activation and Arterial Thrombosis
Musumeci, Lucia ULg; Kuijpers, Marijke; Gilio, Karen et al

in Circulation (2015), 131(7), 656-68

Background A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. Better understanding of the molecular mechanisms leading to platelet ... [more ▼]

Background A limitation of current antiplatelet therapies is their inability to separate thrombotic events from bleeding occurrences. Better understanding of the molecular mechanisms leading to platelet activation is of importance for the development of improved therapies. Recently, protein tyrosine phosphatases (PTPs) have emerged as critical regulators of platelet function. Methods and Results This is the first report implicating the dual-specificity phosphatase 3 (DUSP3) in platelet signaling and thrombosis. This phosphatase is highly expressed in human and mouse platelets. Platelets from DUSP3-deficient mice displayed a selective impairment of aggregation and granule secretion mediated through the collagen receptor glycoprotein VI (GPVI) and the C-type lectin-like receptor 2 (CLEC-2). DUSP3-deficient mice were more resistant to collagen- and epinephrine-induced thromboembolism, compared to wild-type mice, and showed severely impaired thrombus formation upon ferric chloride-induced carotid artery injury. Intriguingly, bleeding times were not altered in DUSP3-deficient mice. At the molecular level, DUSP3 deficiency impaired Syk tyrosine phosphorylation, subsequently reducing phosphorylation of PLCγ2 and calcium fluxes. To investigate DUSP3 function in human platelets, a novel small-molecule inhibitor of DUSP3 was developed. This compound specifically inhibited collagen and CLEC-2-induced human platelet aggregation, thereby phenocopying the effect of DUSP3 deficiency in murine cells. Conclusions DUSP3 plays a selective and essential role in collagen- and CLEC-2-mediated platelet activation and thrombus formation in vivo. Inhibition of DUSP3 may prove therapeutic for arterial thrombosis. This is the first time a PTP, implicated in platelet signaling, has been targeted with a small-molecule drug. [less ▲]

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See detailPurinergic control of inflammation and thrombosis: Role of P2X1 receptors
Oury, Cécile ULg; LECUT, Christelle ULg; Hego, Alexandre ULg et al

in Computational and Structural Biotechnology Journal (2015), 13

Inflammation shifts the hemostatic mechanisms in favor of thrombosis. Upon tissue damage or infection, a sudden increase of extracellular ATP occurs, that might contribute to the crosstalk between ... [more ▼]

Inflammation shifts the hemostatic mechanisms in favor of thrombosis. Upon tissue damage or infection, a sudden increase of extracellular ATP occurs, that might contribute to the crosstalk between inflammation and thrombosis. On platelets, P2X1 receptors act to amplify platelet activation and aggregation induced by other platelet agonists. These receptors critically contribute to thrombus stability in small arteries. Besides platelets, studies by our group indicate that these receptors are expressed by neutrophils. They promote neutrophil chemotaxis, both in vitro and in vivo. In a laser-induced injury mouse model of thrombosis, it appears that neutrophils are required to initiate thrombus formation and coagulation activation on inflamed arteriolar endothelia. In thismodel, by using P2X1−/−mice,we recently showed that P2X1 receptors, expressed on platelets and neutrophils, play a key role in thrombus growth and fibrin generation. Intriguingly, in a model of endotoxemia, P2X1−/−mice exhibited aggravated oxidative tissue damage, along with exacerbated thrombocytopenia and increased activation of coagulation, which translated into higher susceptibility to septic shock. Thus, besides its ability to recruit neutrophils and platelets on inflamed endothelia, the P2X1 receptor also contributes to limit the activation of circulating neutrophils under systemic inflammatory conditions. Taken together, these data suggest that P2X1 receptors are involved in the interplay between platelets, neutrophils and thrombosis. We propose that activation of these receptors by ATP on neutrophils and platelets represents a new mechanism that regulates thrombo-inflammation. [less ▲]

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See detailP2X1 expressed on polymorphonuclear neutrophils and platelets is required for thrombosis in mice
Darbousset, Roxane; Delierneux, Céline ULg; Mezouar, Soraya et al

in Blood (2014), 124

Adenosine Triphosphate (ATP) and its metabolite, adenosine, are key regulators of polymorphonuclear neutrophils (PMNs) functions. PMNs have recently been implicated in the initiation of thrombosis. We ... [more ▼]

Adenosine Triphosphate (ATP) and its metabolite, adenosine, are key regulators of polymorphonuclear neutrophils (PMNs) functions. PMNs have recently been implicated in the initiation of thrombosis. We investigated the role of ATP and adenosine in PMN activation and recruitment at the site of endothelial injury. Following binding to the injured vessel wall, PMNs are activated and release elastase. The recruitment of PMNs and the subsequent fibrin generation and thrombus formation are strongly affected in mice deficient in the P2X1-ATP receptor and in wild-type mice treated with CGS 21680, an agonist of the A2A adenosine receptor or NF449 a P2X1 antagonist. Infusion of wild-type PMNs into P2X1-deficient mice increases fibrin generation but not thrombus formation. Restoration of thrombosis requires infusion of both platelets and PMNs from wild-type mice. In vitro, ATP activates PMNs, whereas CGS 21680 prevents their binding to activated endothelial cells. These data indicate that ATP contributes to PMN activation leading to their adhesion at the site of laser-induced endothelial injury, a necessary step leading to the generation of fibrin and subsequent platelet-dependent thrombus formation. Altogether, our study identifies previously unknown mechanisms by which ATP and adenosine are key molecules involved in thrombosis by regulating the activation state of PMNs. [less ▲]

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See detailCAMKKβ/AMPK-α1 pathway regulates phosphorylation of cytoskeletal targets in thrombin-stimulated human platelets
Onselaer, Marie-Blanche; Oury, Cécile ULg; Hunter, Roger W et al

in Journal of Thrombosis and Haemostasis [=JTH] (2014), 12(6), 973-986

Background. Platelet activation requires sweeping morphological changes, supported by contraction and remodelling of platelet actin cytoskeleton. In various other cell types, AMP-activated protein kinase ... [more ▼]

Background. Platelet activation requires sweeping morphological changes, supported by contraction and remodelling of platelet actin cytoskeleton. In various other cell types, AMP-activated protein kinase (AMPK) controls the phosphorylation state of cytoskeletal targets. Objective. We hypothesized that AMPK is activated during platelet aggregation and contributes to the control of cytoskeletal targets. Results. We found that AMPK-α1 was mainly activated by thrombin and not by other platelet agonists in purified human platelets. Thrombin activated AMPK-α1 ex vivo via a Ca2+/calmodulin-dependent kinase kinase β (CAMKKβ)-dependent pathway. Pharmacological inhibition of CAMKKβ blocked thrombin-induced platelet aggregation and counteracted thrombin-induced phosphorylation of several cytoskeletal proteins, namely, regulatory myosin light chains (MLC), cofilin and vasodilator-stimulated phosphoprotein (VASP), three key elements involved in actin cytoskeleton contraction and polymerization. Platelets isolated from mice lacking AMPK-α1 exhibited reduced aggregation in response to thrombin, associated with a defect in MLC, cofilin and VASP phosphorylation and actin polymerization. More importantly, we show for the first time that AMPK pathway was activated in platelets of patients undergoing major cardiac surgery, in a heparin-sensitive manner. Conclusion. AMPK-α1 is activated by thrombin in human platelets. It controls phosphorylation of key cytoskeletal targets and actin cytoskeleton remodelling during platelet aggregation. [less ▲]

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See detailCombined use of GWAS and eQTL information to identify genes controlling platelet biology
Gori, Ann-Stephan ULg; LECUT, Christelle ULg; Theatre, Emilie ULg et al

Poster (2014, April 24)

Genome Wide Association Studies (GWAS) have identified at least 68 loci involved in megakaryopoiesis and platelet formation. As for all GWAS, identified risk loci span hundreds of kilobases encompassing ... [more ▼]

Genome Wide Association Studies (GWAS) have identified at least 68 loci involved in megakaryopoiesis and platelet formation. As for all GWAS, identified risk loci span hundreds of kilobases encompassing multiple genes, such that causative variants and genes remain largely unknown. To aid in the identification of causative genes underlying GWAS hits for platelet function (as well as other phenotypes including common complex diseases), we have generated a dataset (" CEDAR ") comprising genome-wide SNP and transcriptome data on nine primary cell types, including platelets, for 330 healthy Caucasian individuals. In addition, we have measured platelet counts and volume, as well as platelet reactivity to ADP, collagen and thrombin-related peptide for all these individuals. After extensive quality control, the ensuing data set has been used to identify (i) QTL influencing platelet count, volume and reactivity, and (ii) cis-and transacting eQTL operating in platelets. To aid in the identification of genes underlying platelet biology, we are applying a recently developed method to search for correlations between association patterns with platelet phenotypes and eQTL association patterns. Such findings would strongly incriminate the corresponding genes (affected by the eQTL) as being causally involved in determining the cognate platelet phenotype. Latest results will be presented. [less ▲]

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See detailConnection between cardiac vascular permeability, myocardial oedema and inflammation during sepsis: role of the alpha1AMPK isoform
Castanares-Zapatero, Diego; Bouleti, C; Sommereyns, C et al

in Critical Care Medicine (2013), 41(12), 411-22

Objective: Since AMP-activated protein kinase (AMPK) both controls cytoskeletonorganization in endothelial cells (ECs) and exerts anti-inflammatory effects, we here postulated that it could influence ... [more ▼]

Objective: Since AMP-activated protein kinase (AMPK) both controls cytoskeletonorganization in endothelial cells (ECs) and exerts anti-inflammatory effects, we here postulated that it could influence vascular permeability and inflammation, thereby counteracting cardiac wall oedema during sepsis. Design: Controlled animal study Settings: University research laboratory Subjects: C57BL/6J, α1AMPK-/- and α1AMPK+/+ mice Intervention: Sepsis was triggered in vivo using a sub-lethal injection of lipopolysaccharide (LPS, O55B5, 10 mg.kg-1), inducing systolic left ventricular (LV) dysfunction. LV function, oedema, vascular permeability and inflammation were assessed in vivo in both wild type (WT) mice (α1AMPK+/+) and α1AMPK-deficient mice (α1AMPK-/-). 5-Aminoimidazole-4-carboxamide riboside (AICAr) served to study the impact of AMPK activation on vascular permeability in vivo. The integrity of EC monolayers was also examined in vitro after LPS challenge in the presence of AICAr and/or after α1AMPK silencing. Measurements and main results: α1AMPK-deficiency dramatically impaired tolerance to LPS challenge. Indeed, α1AMPK-/- exhibited heightened cardiac vascular permeability after LPS challenge compared to α1AMPK+/+. Consequently, an increase in LV mass corresponding to exaggerated wall oedema occurred in α1AMPK-/-, without any further decrease in systolic function. Mechanistically, the LPS-induced α1AMPK-/- cardiac phenotype could not be attributed to major changes in the systemic inflammatory response, but was due to an increased disruption of interendothelial tight junctions. Accordingly, AMPK activation by AICAr counteracted LPS-induced hyperpermeability in WT mice in vivo as well as in ECs in vitro. This effect was associated with a potent protection of ZO-1 linear border pattern in ECs. Conclusions: Our results demonstrate, for the first time the involvement of a signalling pathway in the control of LV wall oedema during sepsis. AMPK exerts a protective action through the preservation of interendothelial tight junctions. Interestingly, exaggerated LV wall oedema was not coupled with aggravated systolic dysfunction. However, it could contribute to diastolic dysfunction in septic patients. [less ▲]

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See detailIdentification of biomarkers of hemostatic, endothelial and immune function in sepsis
GOTHOT, André ULg; GOSSET, Christian ULg; FOGUENNE, Jacques ULg et al

in Belgian Journal of Hematology (2013)

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