Epithelial-to-Mesenchymal Transitions modulate interactions between Circulating Tumor Cells and the coagulation system: implication for the metastatic spread.
Bourcy, Morgane ; ; Francart, Marie-Emilie et al
Poster (2015, May)Detailed reference viewed: 6 (0 ULg)
Reflections about the optimisation of the treatment of tendinopathies with PRP
Kaux, Jean-François ; ; LECUT, Christelle 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 ▲]Detailed reference viewed: 45 (13 ULg)
DUSP3 Phosphatase Deficiency or Inhibition Limit Platelet Activation and Arterial Thrombosis
Musumeci, Lucia ; ; 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 ▲]Detailed reference viewed: 127 (54 ULg)
Involvement of Epithelial-to-Mesenchymal Transitions on the interactions between Circulating Tumor Cells and the coagulation system: implication for the metastatic spread.
Bourcy, Morgane ; ; Francart, Marie-Emilie et al
Poster (2015, February)Detailed reference viewed: 14 (3 ULg)
Regulation of Tissue Factor by Epithelial-to-Mesenchymal Transitions: Impacts for the metastatic progression.
; Bourcy, Morgane ; et al
Poster (2015, January 27)Detailed reference viewed: 12 (0 ULg)
Purinergic control of inflammation and thrombosis: Role of P2X1 receptors
Oury, Cécile ; LECUT, Christelle ; Hego, Alexandre 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 ▲]Detailed reference viewed: 40 (17 ULg)
Epithelial-mesenchymal transition induces tissue factor and pro-coagulant properties supporting early metastasis of circulating tumor cells.
Bourcy, Morgane ; ; Francart, Marie-Emilie et al
Poster (2015)Detailed reference viewed: 15 (3 ULg)
Elevated Plasma Soluble ST2 Is Associated with Heart Failure Symptoms and Outcome in Aortic Stenosis.
LANCELLOTTI, Patrizio ; DULGHERU, Raluca Elena ; et al
in PloS one (2015), 10(9), 0138940
B-type natriuretic peptide (BNP) is often used as a complementary finding in the diagnostic work-up of patients with aortic stenosis (AS). Whether soluble ST2, a new biomarker of cardiac stretch, is ... [more ▼]
B-type natriuretic peptide (BNP) is often used as a complementary finding in the diagnostic work-up of patients with aortic stenosis (AS). Whether soluble ST2, a new biomarker of cardiac stretch, is associated with symptomatic status and outcome in asymptomatic AS is unknown. sST2 and BNP levels were measured in 86 patients (74+/-13 years; 59 asymptomatic, 69%) with AS (<1.5 cm2) and preserved left ventricular ejection fraction who were followed-up for 26+/-16 months. Both BNP and sST2 were associated with NYHA class but sST2 (>23 ng/mL, AUC = 0.68, p<0.01) was more accurate to identify asymptomatic patients or those who developed symptoms during follow-up. sST2 was independently related to left atrial index (p<0.0001) and aortic valve area (p = 0.004; model R2 = 0.32). A modest correlation was found with BNP (r = 0.4, p<0.01). During follow-up, 29 asymptomatic patients (34%) developed heart failure symptoms. With multivariable analysis, peak aortic jet velocity (HR = 2.7, p = 0.007) and sST2 level (HR = 1.04, p = 0.03) were independent predictors of cardiovascular events. In AS, sST2 levels could provide complementary information regarding symptomatic status, new onset heart failure symptoms and outcome. It might become a promising biomarker in these patients. [less ▲]Detailed reference viewed: 34 (6 ULg)
Biological Effects of Cardiac Magnetic Resonance on Human Blood Cells.
LANCELLOTTI, Patrizio ; NCHIMI LONGANG, Alain ; Delierneux, Céline et al
in Circulation. Cardiovascular imaging (2015), 8(9),
BACKGROUND: Cardiac magnetic resonance (CMR) is increasingly used for the diagnosis and management of cardiac diseases. Recent studies have reported immediate post-CMR DNA double-strand breaks in T ... [more ▼]
BACKGROUND: Cardiac magnetic resonance (CMR) is increasingly used for the diagnosis and management of cardiac diseases. Recent studies have reported immediate post-CMR DNA double-strand breaks in T lymphocytes. We sought to evaluate CMR-induced DNA damage in lymphocytes, alterations of blood cells, and their temporal persistence. METHODS AND RESULTS: In 20 prospectively enrolled healthy men (31.4+/-7.9 years), blood was drawn before and after (1-2 hours, 2 days, 1 month, and 1 year) unenhanced 1.5T CMR. Blood cell counts, cell death, and activation status of lymphocytes, monocytes, neutrophils, and platelets were evaluated. The first 2-hour post-CMR were characterized by a small increase of lymphocyte B and neutrophil counts and a transient drop of total lymphocytes because of a decrease in natural killer cells. Among blood cells, only neutrophils and monocytes displayed slight and transient activation. DNA double-strand breaks in lymphocytes were quantified through flow cytometric analysis of H2AX phosphorylation (gamma-H2AX). gamma-H2AX intensity in T lymphocytes did not change early after CMR but increased significantly at day 2 </=1 month before returning to baseline levels of 1-year post-CMR. CONCLUSIONS: Unenhanced CMR is associated with minor but significant immediate blood cell alterations or activations figuring inflammatory response, as well as DNA damage in T lymphocytes observed from day 2 until the first month but disappearing at 1-year follow-up. Although further studies are required to definitely state whether CMR can be used safely, our findings already call for caution when it comes to repeat this examination within a month. [less ▲]Detailed reference viewed: 29 (5 ULg)
In vitro study of the specific interaction between poly (2-dimethylamino ethylmethacrylate) based polymers with platelets and red blood cells.
Flebus, Luca ; Lombart, François ; et al
in International Journal of Pharmaceutics (2015), 492
Poly(2-dimethylamino)ethyl methacrylate (PDMAEMA) is an attractive polycation frequently proposed as a non-viral vector for gene therapy. As expected for other cationic carriers, intravenous ... [more ▼]
Poly(2-dimethylamino)ethyl methacrylate (PDMAEMA) is an attractive polycation frequently proposed as a non-viral vector for gene therapy. As expected for other cationic carriers, intravenous administration of PDMAEMA can result in its ionic complexation with various negatively charged domains found within the blood. To gain more insight into this polycation hemoreactivity, we followed the binding kinetics of a free form (FF) of fluorescein labelled PDMAEMA (below 15 kDa) in normal human blood using flow cytometry. This in vitro study highlighted that platelets display higher affinity for this polycation compared to red blood cells (RBCs), with an adsorption isotherm characteristics of a specific saturable binding site. PDMAEMA (1-20μg/mL) exerted a concentration dependent proaggregant effect with a biphasic aggregation of washed platelets. Activation of platelets was also noticed in whole blood with the expression of P-selectin and fibrinogen on platelet surface. Although additional studies would be needed in order to elucidate the mechanism of PDMAEMA mediated activation of platelets, our manuscript provides important information on the hemoreactivity of FF PDMAEMA. [less ▲]Detailed reference viewed: 29 (13 ULg)
Erratum: Elevated basal levels of circulating activated platelets predict ICU-acquired sepsis and mortality: a prospective study.
; Delierneux, Céline ; et al
in Critical care (London, England) (2015), 19(1), 301Detailed reference viewed: 22 (2 ULg)
Erratum: Prospective immune profiling in critically ill adults: before, during and after severe sepsis and septic shock.
; GOSSET, Christian ; Delierneux, Céline et al
in Critical care (London, England) (2015), 19(1), 300Detailed reference viewed: 14 (4 ULg)
Positron Emission Tomography/Computed Tomography Imaging in Device Infective Endocarditis: Ready for Prime Time
Lancellotti, Patrizio ; ; Oury, Cécile et al
in Circulation (2015)
Over the last decade there has been a remarkable increase in prosthetic heart valve replacement and cardiac implantable electronic device utilization. Although capable of improving the quality and ... [more ▼]
Over the last decade there has been a remarkable increase in prosthetic heart valve replacement and cardiac implantable electronic device utilization. Although capable of improving the quality and quantity of life of patients suffering from severe valvular heart disease or rhythm disorders, they are both subject to potentially life-threatening infection involving the endocardium, referred to as device infective endocarditis (DIE)1,2. The rate of prosthetic valve endocarditis (PVE) ranges from 1-6% to 15%, being higher in revision surgery1. The infection usually involves the junction between the sewing ring and the annulus, leading to perivalvular abscess, dehiscence, pseudo-aneurysms, and fistulae, or the leaflets of the prosthesis, leading to vegetations, cusp rupture, and perforation. Cardiac device-related infective endocarditis (CDRIE), to be distinguished from local device infection (pocket/generator), is defined as an infection involving the electrode leads, cardiac valve leaflets, or endocardial surface. An incidence of 1.4 per 1000 device-years of definite CDRIE has been reported3. DIE may occur at anytime, being related to surgery only in early cases. [less ▲]Detailed reference viewed: 39 (17 ULg)
Left ventricular regional function and maximal exercise capacity in aortic stenosis.
DULGHERU, Raluca Elena ; ; DAVIN, Laurent et al
in European heart journal cardiovascular Imaging (2015)
AIMS: The objective assessment of maximal exercise capacity (MEC) using peak oxygen consumption (VO2) measurement may be helpful in the management of asymptomatic aortic stenosis (AS) patients. However ... [more ▼]
AIMS: The objective assessment of maximal exercise capacity (MEC) using peak oxygen consumption (VO2) measurement may be helpful in the management of asymptomatic aortic stenosis (AS) patients. However, the relationship between left ventricular (LV) function and MEC has been relatively unexplored. We aimed to identify which echocardiographic parameters of LV systolic function can predict MEC in asymptomatic AS. METHODS AND RESULTS: Asymptomatic patients with moderate to severe AS (n = 44, aortic valve area <1.5 cm2, 66 +/- 13 years, 75% of men) and preserved LV ejection fraction (LVEF > 50%) were prospectively referred for resting echocardiography and cardiopulmonary exercise test. LV longitudinal strain (LS) of each myocardial segment was measured by speckle tracking echocardiography (STE) from the apical (aLS) 4-, 2-, and 3-chamber views. An average value of the LS of the analysable segments was provided for each myocardial region: basal (bLS), mid (mLS), and aLS. LV circumferential and radial strains were measured from short-axis views. Peak VO2 was 20.1 +/- 5.8 mL/kg/min (median 20.7 mL/kg/min; range 7.2-32.3 mL/kg/min). According to the median of peak VO2, patients with reduced MEC were significantly older (P < 0.001) and more frequently females (P = 0.05). There were significant correlations between peak VO2 and age (r = -0.44), LV end-diastolic volume (r = 0.35), LV stroke volume (r = 0.37), indexed stroke volume (r = 0.32), and E/e' ratio (r = -0.37, all P < 0.04). Parameters of AS severity and LVEF did not correlate with peak VO2 (P = NS for all). Among LV deformation parameters, bLS and mLS were significantly associated with peakVO2 (r = 0.43, P = 0.005, and r = 0.32, P = 0.04, respectively). With multivariable analysis, female gender (beta = 4.9; P = 0.008) and bLS (beta = 0.50; P = 0.03) were the only independent determinants (r2 = 0.423) of peak VO2. CONCLUSION: In asymptomatic AS, impaired LV myocardial longitudinal function determines reduced MEC. Basal LS was the only parameter of LV regional function independently associated with MEC. [less ▲]Detailed reference viewed: 23 (1 ULg)
Poster session 6: Saturday 6 December 2014, 08:30-12:30Location: Poster area.
; DULGHERU, Raluca Elena ; et al
Poster (2014, December)Detailed reference viewed: 9 (1 ULg)
Poster session 5: Friday 5 December 2014, 14:00-18:00Location: Poster area.
; DULGHERU, Raluca Elena ; et al
Poster (2014, December)Detailed reference viewed: 28 (10 ULg)
P2X1 expressed on polymorphonuclear neutrophils and platelets is required for thrombosis in mice
; Delierneux, Céline ; 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 ▲]Detailed reference viewed: 29 (5 ULg)
Rasa3 Controls Megakaryocyte Rap1 Activation, Integrin Signaling and Differentiation into Proplatelet
Molina Ortiz, Patricia ; ; Ramery, Eve et al
in PLoS Genetics (2014), 10(6), 1004420
Rasa3 is a GTPase activating protein of the GAP1 family which targets Ras and Rap1. Ubiquitous Rasa3 catalytic inactivation in mouse results in early embryonic lethality. Here, we show that Rasa3 ... [more ▼]
Rasa3 is a GTPase activating protein of the GAP1 family which targets Ras and Rap1. Ubiquitous Rasa3 catalytic inactivation in mouse results in early embryonic lethality. Here, we show that Rasa3 catalytic inactivation in mouse hematopoietic cells results in a lethal syndrome characterized by severe defects during megakaryopoiesis, thrombocytopenia and a predisposition to develop preleukemia. The main objective of this study was to define the cellular and the molecular mechanisms of terminal megakaryopoiesis alterations. We found that Rasa3 catalytic inactivation altered megakaryocyte development, adherence, migration, actin cytoskeleton organization and differentiation into proplatelet forming megakaryocytes. These megakaryocyte alterations were associated with an increased active Rap1 level and a constitutive integrin activation. Thus, these mice presented a severe thrombocytopenia, bleeding and anemia associated with an increased percentage of megakaryocytes in the bone marrow, bone marrow fibrosis, extramedular hematopoiesis, splenomegaly and premature death. Altogether, our results indicate that Rasa3 catalytic activity controls Rap1 activation and integrin signaling during megakaryocyte differentiation in mouse. [less ▲]Detailed reference viewed: 316 (12 ULg)
CAMKKβ/AMPK-α1 pathway regulates phosphorylation of cytoskeletal targets in thrombin-stimulated human platelets
; Oury, Cécile ; 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 ▲]Detailed reference viewed: 25 (2 ULg)