The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Mariechristine Bouton - One of the best experts on this subject based on the ideXlab platform.
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Protease Nexin 1 deficiency increases mouse hindlimb neovascularisation following ischemia and accelerates femoral artery perfusion
Scientific Reports, 2021Co-Authors: Mariechristine Bouton, Yacine Boulaftali, Sonia Selbonne, Celina Madjene, Benjamin Salmon, Veronique ArocasAbstract:We previously identified the inhibitory serpin Protease Nexin-1 (PN-1) as an important player of the angiogenic balance with anti-angiogenic activity in physiological conditions. In the present study, we aimed to determine the role of PN-1 on pathological angiogenesis and particularly in response to ischemia, in the mouse model induced by femoral artery ligation. In wild-type (WT) muscle, we observed an upregulation of PN-1 mRNA and protein after ischemia. Angiography analysis showed that femoral artery perfusion was more rapidly restored in PN-1-/- mice than in WT mice. Moreover, immunohistochemistry showed that capillary density increased following ischemia to a greater extent in PN-1-/- than in WT muscles. Moreover, leukocyte recruitment and IL-6 and MCP-1 levels were also increased in PN-1-/- mice compared to WT after ischemia. This increase was accompanied by a higher overexpression of the growth factor midkine, known to promote leukocyte trafficking and to modulate expression of proinflammatory cytokines. Our results thus suggest that the higher expression of midkine observed in PN-1- deficient mice can increase leukocyte recruitment in response to higher levels of MCP-1, finally driving neoangiogenesis. Thus, PN-1 can limit neovascularisation in pathological conditions, including post-ischemic reperfusion of the lower limbs.
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Protease Nexin 1 in the cardiovascular system wherefore art thou
Frontiers in Cardiovascular Medicine, 2021Co-Authors: Mariechristine Bouton, Benjamin Richard, Veronique Arocas, Celina Madjene, Alexandre BoutignyAbstract:The balance between Proteases and Protease inhibitors plays a critical role in tissue remodeling during cardiovascular diseases. Different serine Protease inhibitors termed serpins, which are expressed in the cardiovascular system, can exert a fine-tuned regulation of Protease activities. Among them, Protease Nexin-1 (PN-1, encoded by SERPINE2) is a very powerful thrombin inhibitor and can also inactivate plasminogen activators and plasmin. Studies have shown that this serpin is expressed by all cell subpopulations in the vascular wall and by circulating cells but is barely detectable in plasma in the free form. PN-1 present in platelet granules and released upon activation has been shown to present strong antithrombotic and antifibrinolytic properties. PN-1 has a broad spectrum of action related to both hemostatic and blood vessel wall Protease activities. Different studies showed that PN-1 is not only an important protector of vascular cells against Protease activities but also a significant actor in the clearance of the complexes it forms with its targets. In this context, PN-1 overexpression has been observed in the pathophysiology of thoracic aortic aneurysms (TAA) and during the development of atherosclerosis in humans. Similarly, in the heart, PN-1 has been shown to be overexpressed in a mouse model of heart failure and to be involved in cardiac fibrosis. Overall, PN-1 appears to serve as a "hand brake" for Protease activities during cardiovascular remodeling. This review will thus highlight the role of PN-1 in the cardiovascular system and deliver a comprehensive assessment of its position among serpins.
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development and characterization of single domain antibodies neutralizing Protease Nexin 1 as tools to increase thrombin generation
Journal of Thrombosis and Haemostasis, 2020Co-Authors: Charlotte Kawecki, Mariechristine Bouton, Yacine Boulaftali, Veronique Arocas, Laurence Venisse, Karen Aymonnier, Stephen Ferriere, Olivier D Christophe, Peter J Lenting, Cecile V DenisAbstract:BACKGROUND Protease Nexin-1 (PN-1) is a member of the serine Protease inhibitor (Serpin)-family, with thrombin as its main target. Current polyclonal and monoclonal antibodies against PN-1 frequently cross-react with plasminogen activator inhibitor-1 (PAI-1), a structurally and functionally homologous Serpin. OBJECTIVES Here, we aimed to develop inhibitory single-domain antibodies (VHHs) that show specific binding to both human (hPN-1) and murine (mPN-1) PN-1. METHODS PN-1-binding VHHs were isolated via phage-display using llama-derived or synthetic VHH-libraries. Following bacterial expression, purified VHHs were analyzed in binding and activity assays. RESULTS AND CONCLUSIONS By using a llama-derived library, 2 PN-1 specific VHHs were obtained (KB-PN1-01 and KB-PN1-02). Despite their specificity, none displayed inhibitory activity toward hPN-1 or mPN-1. From the synthetic library, 4 VHHs (H12, B11, F06, A08) could be isolated that combined efficient binding to both hPN-1 and mPN-1 with negligible binding to PAI-1. Of these, B11, F06, and A08 were able to fully restore thrombin activity by blocking PN-1. As monovalent VHH, half-maximal inhibitory concentration values for hPN-1 were 50 ± 10, 290 ± 30, and 960 ± 390 nmol/L, for B11, F06, and A08, respectively, and 1580 ± 240, 560 ± 130, and 2880 ± 770 nmol/L for mPN-1. The inhibitory potential was improved 4- to 7-fold when bivalent VHHs were engineered. Importantly, all VHHs could block PN-1 activity in plasma as well as PN-1 released from activated platelets, one of the main sources of PN-1 during hemostasis. In conclusion, we report the generation of inhibitory anti-PN-1 antibodies using a specific approach to avoid cross-reactivity with the homologous Serpin PAI-1.
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Targeting Protease Nexin-1, a natural anticoagulant serpin, to control bleeding and improve hemostasis in hemophilia
Blood, 2019Co-Authors: Karen Aymonnier, Yacine Boulaftali, Veronique Arocas, Laurence Venisse, Charlotte Kawecki, Olivier Christophe, Peter Lenting, Emmanuelle De Raucourt, Cécile Denis, Mariechristine BoutonAbstract:Hemophilia A and B, diseases caused by the lack of factor VIII (FVIII) and factor IX (FIX) respectively, lead to insufficient thrombin production, and therefore to bleeding. New therapeutic strategies for hemophilia treatment that do not rely on clotting factor replacement, but imply the neutralization of natural anticoagulant proteins, have recently emerged. We propose an innovative approach consisting of targeting a natural and potent thrombin inhibitor, expressed by platelets, called Protease Nexin-1 (PN-1). By using the calibrated automated thrombin generation assay, we showed that a PN-1-neutralizing antibody could significantly shorten the thrombin burst in response to tissue factor in platelet-rich plasma (PRP) from patients with mild or moderate hemophilia. In contrast, in PRP from patients with severe hemophilia, PN-1 neutralization did not improve thrombin generation. However, after collagen-induced platelet activation, PN-1 deficiency in F8-/-mice or PN-1 blocking in patients with severe disease led to a significantly improved thrombin production in PRP, underlining the regulatory role of PN-1 released from platelet granules. In various bleeding models, F8-/-/PN-1-/- mice displayed significantly reduced blood loss and bleeding time compared with F8-/-mice. Moreover, platelet recruitment and fibrin(ogen) accumulation were significantly higher in F8-/-/PN-1-/- mice than in F8-/-mice in the ferric chloride-induced mesenteric vessel injury model. Thromboelastometry studies showed enhanced clot stability and lengthened clot lysis time in blood from F8-/-/PN-1-/- and from patients with hemophilia A incubated with a PN-1-neutralizing antibody compared with their respective controls. Our study thus provides proof of concept that PN-1 neutralization can be a novel approach for future clinical care in hemophilia.
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Protease Nexin-1 regulates retinal vascular development
Cellular and Molecular Life Sciences, 2015Co-Authors: Sonia Selbonne, Mariechristine Bouton, Yacine Boulaftali, Deborah Francois, William Raoul, Florian Sennlaub, Martine Jandrot-perrus, Veronique ArocasAbstract:We recently identified Protease Nexin-1 (PN-1) or serpinE2, as a possibly underestimated player in maintaining angiogenic balance. Here, we used the well-characterized postnatal vascular development of newborn mouse retina to further investigate the role and the mechanism of action of PN-1 in physiological angiogenesis. The development of retinal vasculature was analysed by endothelial cell staining with isolectin B4. PN-1-deficient (PN-1-/-) retina displayed increased vascularization in the postnatal period, with elevated capillary thickness and density, compared to their wild-type littermate (WT). Moreover, PN-1-/-retina presented more veins/arteries than WT retina. The kinetics of retinal vasculature development , retinal VEGF expression and overall retinal structure were similar in WT and PN-1-/-mice, but we observed a hyperproliferation of vascular cells in PN-1-/-retina. Expression of PN-1 was analysed by immunoblot-ting and X-Gal staining of retinas from mice expressing beta-galactosidase under a PN-1 promoter. PN-1 was highly expressed in the first week following birth and then progressively decreased to a low level in adult retina where it localized on the retinal arteries. PCR arrays performed on mouse retinal RNA identified two angiogenesis-related factors, midkine and Smad5, that were overexpressed in PN-1-/-newborn mice and this was confirmed by RT-PCR. Both the higher vascularization and the overexpres-sion of midkine and Smad5 mRNA were also observed in gastrocnemius muscle of PN-1-/-mice, suggesting that PN-1 interferes with these pathways. Together, our results demonstrate that PN-1 strongly limits physiological angiogenesis and suggest that modulation of PN-1 expression could represent a new way to regulate angiogenesis.
Denis Monard - One of the best experts on this subject based on the ideXlab platform.
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serpine2 Protease Nexin 1 in vivo multiple functions does the puzzle make sense
Seminars in Cell & Developmental Biology, 2017Co-Authors: Denis MonardAbstract:Cultures of glial cells and fibroblasts allowed and lead to the identification SERPINE2/Protease Nexin-1 (SERPINE2/PN-1). Cellular, biochemical, immunological and molecular characterization substantiated its variable expression in many organs as a function of development, adult stages, pathological situations or following injury. It is not a circulating serpin, but as other members of the family, its target specificity is influenced by components of the extracellular matrix. The challenges are to identify where and when SERPINE2/PN-1 modulatory action becomes crucial or even possibly specific in a mosaic of feasible in vivo impacts. Data providing correlations are not sufficient to satisfy this aim. Genetically modified mice, or tissue derived thereof, provide interesting in vivo models to identify and study the relevance of this serpin. This review will highlight sometimes-intriguing results indicating a crucial impact of SERPINE2/PN-1, especially in the vasculature, the nervous system or the behavior of cancer cells in vivo. Data presently available will be discussed in an attempt to define general trends in the diversity of SERPINE2/PN-1 modes of action in vivo.
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impaired fear extinction in mice lacking Protease Nexin 1
European Journal of Neuroscience, 2010Co-Authors: Marita Meins, Cyril Herry, C Muller, Stephane Ciocchi, Eliza Moreno, Andreas Luthi, Denis MonardAbstract:The serine Protease inhibitor Protease-Nexin-1 (PN-1) has been shown to modulate N-methyl-d-aspartate receptor (NMDAR)-mediated synaptic currents and NMDAR-dependent long-term potentiation of synaptic transmission. Here, we analysed the role of PN-1 in the acquisition and extinction of classical auditory fear conditioning, two distinct forms of learning that both depend on NMDAR activity in the amygdala. Immunostaining revealed that PN-1 is expressed throughout the amygdala, primarily in gamma-aminobutyric acid containing neurons of the central amygdala and intercalated cell masses (ITCs) and in glia. Fear extinction was severely impaired in mice lacking PN-1 (PN-1 KO). Consistent with a role for the basal nucleus of the amygdala in fear extinction, we found that, compared with wild-type (WT) littermate controls, PN-1 KO mice exhibited decreased numbers of Fos-positive neurons in the basal nucleus after extinction. Moreover, immunoblot analysis of laser-microdissected amygdala sub-nuclei revealed specific extinction-induced increases in the level of phosphorylated alpha-calcium/calmodulin protein kinase II in the medial ITCs and in the lateral subdivision of the central amygdala in WT mice. These responses were altered in PN-1 KO mice. Together, these data indicate that lack of extinction in PN-1 KO mice is associated with distinct changes in neuronal activity across the circuitry of the basal and central nuclei and the ITCs, supporting a differential impact on fear extinction of these amygdala substructures. They also suggest a new role for serine Protease inhibitors such as PN-1 in modulating fear conditioning and extinction.
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anticoagulant and antithrombotic properties of platelet Protease Nexin 1
Blood, 2010Co-Authors: Yacine Boulaftali, Benjamin Richard, Laurence Venisse, Denis Monard, Frederic Adam, Veronique Ollivier, Sabrina Taieb, Remi Favier, Mariechristine Alessi, Marijke BryckaertAbstract:Protease Nexin-1 (PN-1) is a serpin that inhibits plasminogen activators, plasmin, and thrombin. PN-1 is barely detectable in plasma but is expressed by platelets. Here, we studied platelet PN-1 in resting and activated conditions and its function in thrombosis. Studies on human platelets from healthy donors and from patients with a Gray platelet syndrome demonstrate that PN-1 is present both at the platelet surface and in alpha-granules. The role of PN-1 was investigated in vitro using human platelets incubated with a blocking antibody and using platelets from PN-1-deficient mice. Both approaches indicate that platelet PN-1 is active on thrombin and urokinase-type plasminogen activator. Blockade and deficiency of platelet PN-1 result in accelerated and increased tissue factor-induced thrombin generation as indicated by calibrated automated thrombography. Moreover, platelets from PN-1-deficient mice respond to subthreshold doses of thrombin, as assessed by P-selectin expression and platelet aggregation. Thrombus formation, induced ex vivo by collagen in blood flow conditions and in vivo by FeCl(3)-induced injury, is significantly increased in PN-1-deficient mice, demonstrating the antithrombotic properties of platelet PN-1. Platelet PN-1 is thus a key player in the thrombotic process, whose negative regulatory role has been, up to now, markedly underestimated.
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the serine Protease inhibitor Protease Nexin 1 controls mammary cancer metastasis through lrp 1 mediated mmp 9 expression
Cancer Research, 2009Co-Authors: Berengere Fayard, Eliza Moreno, Fabrizio Bianchi, Julien H Dey, Sabrina Djaffer, Nancy E Hynes, Denis MonardAbstract:Through their ability to degrade the extracellular matrix, Proteases mediate cancer cell invasion and metastasis. Paradoxically, some serine Protease inhibitors (serpins) are often overexpressed in human tumors. Using computational analysis, we found that the RNA level of Protease Nexin-1 (PN-1), a serpin that blocks numerous Proteases activity, is significantly elevated in estrogen receptor-alpha-negative and in high-grade breast cancer. The in silico approach was complemented by mechanistic studies on two mammary cancer cell lines, the PN-1-negative 168FARN cells and the PN-1-positive 4T1 cells, both of which form primary mammary tumors, but only 4T1 tumors are able to metastasize to the lungs. We show that treatment of 168FARN cells with PN-1 stimulates extracellular signal-regulated kinase activation via low-density lipoprotein receptor-related protein-1 (LRP-1) binding, resulting in increased matrix metalloproteinase (MMP)-9 RNA, protein, and secreted activity. PN-1-silenced 4T1 cells express low MMP-9 levels. Moreover, injection of PN-1-silenced cells into mice did not affect 4T1 primary mammary tumor outgrowth; however, the tumors had impaired metastatic potential, which could be restored by reexpressing soluble MMP-9 in the PN-1-silenced 4T1 cells. Thus, using mammary tumor models, we describe a novel pathway whereby the serpin PN-1 by binding LRP-1 stimulates extracellular signal-regulated kinase signaling, MMP-9 expression, and metastatic spread of mammary tumors. Importantly, an analysis of 126 breast cancer patients revealed that those whose breast tumors had elevated PN-1 levels had a significantly higher probability to develop lung metastasis, but not metastasis to other sites, on relapse. These results suggest that PN-1 might become a prognostic marker in breast cancer.
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Protease Nexin 1 and its receptor lrp modulate shh signalling during cerebellar development
Development, 2007Co-Authors: Catherine Vaillant, Sabrina Taieb, Eliza Moreno, Odysse Michos, Slobodanka Orolicki, Florence Brellier, Rolf Zeller, Denis MonardAbstract:Development of the postnatal cerebellum relies on the tight regulation of cell number by morphogens that control the balance between cell proliferation, survival and differentiation. Here, we analyze the role of the serine-Protease inhibitor Protease Nexin 1 (PN-1; SERPINE2) in the proliferation and differentiation of cerebellar granular neuron precursors (CGNPs) via the modulation of their main mitogenic factor, sonic hedgehog (SHH). Our studies show that PN-1 interacts with low-density lipoprotein receptor-related proteins (LRPs) to antagonize SHH-induced CGNP proliferation and that it inhibits the activity of the SHH transcriptional target GLI1. The binding of PN-1 to LRPs interferes with SHH-induced cyclin D1 expression. CGNPs isolated from Pn-1-deficient mice exhibit enhanced basal proliferation rates due to overactivation of the SHH pathway and show higher sensitivity to exogenous SHH. In vivo, the Pn-1 deficiency alters the expression of SHH target genes. In addition, the onset of CGNP differentiation is delayed, which results in an enlarged outer external granular layer. Furthermore, the Pn-1 deficiency leads to an overproduction of CGNPs and to enlargement of the internal granular layer in a subset of cerebellar lobes during late development and adulthood. We propose that PN-1 contributes to shaping the cerebellum by promoting cell cycle exit.
Veronique Arocas - One of the best experts on this subject based on the ideXlab platform.
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Protease Nexin 1 deficiency increases mouse hindlimb neovascularisation following ischemia and accelerates femoral artery perfusion
Scientific Reports, 2021Co-Authors: Mariechristine Bouton, Yacine Boulaftali, Sonia Selbonne, Celina Madjene, Benjamin Salmon, Veronique ArocasAbstract:We previously identified the inhibitory serpin Protease Nexin-1 (PN-1) as an important player of the angiogenic balance with anti-angiogenic activity in physiological conditions. In the present study, we aimed to determine the role of PN-1 on pathological angiogenesis and particularly in response to ischemia, in the mouse model induced by femoral artery ligation. In wild-type (WT) muscle, we observed an upregulation of PN-1 mRNA and protein after ischemia. Angiography analysis showed that femoral artery perfusion was more rapidly restored in PN-1-/- mice than in WT mice. Moreover, immunohistochemistry showed that capillary density increased following ischemia to a greater extent in PN-1-/- than in WT muscles. Moreover, leukocyte recruitment and IL-6 and MCP-1 levels were also increased in PN-1-/- mice compared to WT after ischemia. This increase was accompanied by a higher overexpression of the growth factor midkine, known to promote leukocyte trafficking and to modulate expression of proinflammatory cytokines. Our results thus suggest that the higher expression of midkine observed in PN-1- deficient mice can increase leukocyte recruitment in response to higher levels of MCP-1, finally driving neoangiogenesis. Thus, PN-1 can limit neovascularisation in pathological conditions, including post-ischemic reperfusion of the lower limbs.
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Protease Nexin 1 in the cardiovascular system wherefore art thou
Frontiers in Cardiovascular Medicine, 2021Co-Authors: Mariechristine Bouton, Benjamin Richard, Veronique Arocas, Celina Madjene, Alexandre BoutignyAbstract:The balance between Proteases and Protease inhibitors plays a critical role in tissue remodeling during cardiovascular diseases. Different serine Protease inhibitors termed serpins, which are expressed in the cardiovascular system, can exert a fine-tuned regulation of Protease activities. Among them, Protease Nexin-1 (PN-1, encoded by SERPINE2) is a very powerful thrombin inhibitor and can also inactivate plasminogen activators and plasmin. Studies have shown that this serpin is expressed by all cell subpopulations in the vascular wall and by circulating cells but is barely detectable in plasma in the free form. PN-1 present in platelet granules and released upon activation has been shown to present strong antithrombotic and antifibrinolytic properties. PN-1 has a broad spectrum of action related to both hemostatic and blood vessel wall Protease activities. Different studies showed that PN-1 is not only an important protector of vascular cells against Protease activities but also a significant actor in the clearance of the complexes it forms with its targets. In this context, PN-1 overexpression has been observed in the pathophysiology of thoracic aortic aneurysms (TAA) and during the development of atherosclerosis in humans. Similarly, in the heart, PN-1 has been shown to be overexpressed in a mouse model of heart failure and to be involved in cardiac fibrosis. Overall, PN-1 appears to serve as a "hand brake" for Protease activities during cardiovascular remodeling. This review will thus highlight the role of PN-1 in the cardiovascular system and deliver a comprehensive assessment of its position among serpins.
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development and characterization of single domain antibodies neutralizing Protease Nexin 1 as tools to increase thrombin generation
Journal of Thrombosis and Haemostasis, 2020Co-Authors: Charlotte Kawecki, Mariechristine Bouton, Yacine Boulaftali, Veronique Arocas, Laurence Venisse, Karen Aymonnier, Stephen Ferriere, Olivier D Christophe, Peter J Lenting, Cecile V DenisAbstract:BACKGROUND Protease Nexin-1 (PN-1) is a member of the serine Protease inhibitor (Serpin)-family, with thrombin as its main target. Current polyclonal and monoclonal antibodies against PN-1 frequently cross-react with plasminogen activator inhibitor-1 (PAI-1), a structurally and functionally homologous Serpin. OBJECTIVES Here, we aimed to develop inhibitory single-domain antibodies (VHHs) that show specific binding to both human (hPN-1) and murine (mPN-1) PN-1. METHODS PN-1-binding VHHs were isolated via phage-display using llama-derived or synthetic VHH-libraries. Following bacterial expression, purified VHHs were analyzed in binding and activity assays. RESULTS AND CONCLUSIONS By using a llama-derived library, 2 PN-1 specific VHHs were obtained (KB-PN1-01 and KB-PN1-02). Despite their specificity, none displayed inhibitory activity toward hPN-1 or mPN-1. From the synthetic library, 4 VHHs (H12, B11, F06, A08) could be isolated that combined efficient binding to both hPN-1 and mPN-1 with negligible binding to PAI-1. Of these, B11, F06, and A08 were able to fully restore thrombin activity by blocking PN-1. As monovalent VHH, half-maximal inhibitory concentration values for hPN-1 were 50 ± 10, 290 ± 30, and 960 ± 390 nmol/L, for B11, F06, and A08, respectively, and 1580 ± 240, 560 ± 130, and 2880 ± 770 nmol/L for mPN-1. The inhibitory potential was improved 4- to 7-fold when bivalent VHHs were engineered. Importantly, all VHHs could block PN-1 activity in plasma as well as PN-1 released from activated platelets, one of the main sources of PN-1 during hemostasis. In conclusion, we report the generation of inhibitory anti-PN-1 antibodies using a specific approach to avoid cross-reactivity with the homologous Serpin PAI-1.
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Targeting Protease Nexin-1, a natural anticoagulant serpin, to control bleeding and improve hemostasis in hemophilia
Blood, 2019Co-Authors: Karen Aymonnier, Yacine Boulaftali, Veronique Arocas, Laurence Venisse, Charlotte Kawecki, Olivier Christophe, Peter Lenting, Emmanuelle De Raucourt, Cécile Denis, Mariechristine BoutonAbstract:Hemophilia A and B, diseases caused by the lack of factor VIII (FVIII) and factor IX (FIX) respectively, lead to insufficient thrombin production, and therefore to bleeding. New therapeutic strategies for hemophilia treatment that do not rely on clotting factor replacement, but imply the neutralization of natural anticoagulant proteins, have recently emerged. We propose an innovative approach consisting of targeting a natural and potent thrombin inhibitor, expressed by platelets, called Protease Nexin-1 (PN-1). By using the calibrated automated thrombin generation assay, we showed that a PN-1-neutralizing antibody could significantly shorten the thrombin burst in response to tissue factor in platelet-rich plasma (PRP) from patients with mild or moderate hemophilia. In contrast, in PRP from patients with severe hemophilia, PN-1 neutralization did not improve thrombin generation. However, after collagen-induced platelet activation, PN-1 deficiency in F8-/-mice or PN-1 blocking in patients with severe disease led to a significantly improved thrombin production in PRP, underlining the regulatory role of PN-1 released from platelet granules. In various bleeding models, F8-/-/PN-1-/- mice displayed significantly reduced blood loss and bleeding time compared with F8-/-mice. Moreover, platelet recruitment and fibrin(ogen) accumulation were significantly higher in F8-/-/PN-1-/- mice than in F8-/-mice in the ferric chloride-induced mesenteric vessel injury model. Thromboelastometry studies showed enhanced clot stability and lengthened clot lysis time in blood from F8-/-/PN-1-/- and from patients with hemophilia A incubated with a PN-1-neutralizing antibody compared with their respective controls. Our study thus provides proof of concept that PN-1 neutralization can be a novel approach for future clinical care in hemophilia.
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hematopoietic Protease Nexin 1 protects against lung injury by preventing thrombin signaling in mice
Blood Advances, 2018Co-Authors: Deborah Francois, Veronique Arocas, Martine Jandrotperrus, Laurence Venisse, Karen Aymonnier, Leila Idir, Raphael Martos, Salome L Gazit, Ludovic Couty, Eric CamererAbstract:Coagulation and fibrinolytic system deregulation has been implicated in the development of idiopathic pulmonary fibrosis, a devastating form of interstitial lung disease. We used intratracheal instillation of bleomycin to induce pulmonary fibrosis in mice and analyzed the role of serine Protease inhibitor E2 (serpinE2)/Protease Nexin-1 (PN-1), a tissue serpin that exhibits anticoagulant and antifibrinolytic properties. PN-1 deficiency was associated, after bleomycin challenge, with a significant increase in mortality, as well as a marked increase in active thrombin in bronchoalveolar lavage fluids, an overexpression of extracellular matrix proteins, and an accumulation of inflammatory cells in the lungs. Bone marrow transplantation experiments showed that protective PN-1 was derived from hematopoietic cell compartment. A pharmacological strategy using the direct thrombin inhibitor argatroban reversed the deleterious effects of PN-1 deficiency. Concomitant deficiency of the thrombin receptor Protease-activated receptor 4 (PAR4) abolished the deleterious effects of PN-1 deficiency in hematopoietic cells. These data demonstrate that prevention of thrombin signaling by PN-1 constitutes an important endogenous mechanism of protection against lung fibrosis and associated mortality. Our findings suggest that appropriate doses of thrombin inhibitors or PAR4 antagonists may provide benefit against progressive lung fibrosis with evidence of deregulated thrombin activity.
Benjamin Richard - One of the best experts on this subject based on the ideXlab platform.
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Protease Nexin 1 in the cardiovascular system wherefore art thou
Frontiers in Cardiovascular Medicine, 2021Co-Authors: Mariechristine Bouton, Benjamin Richard, Veronique Arocas, Celina Madjene, Alexandre BoutignyAbstract:The balance between Proteases and Protease inhibitors plays a critical role in tissue remodeling during cardiovascular diseases. Different serine Protease inhibitors termed serpins, which are expressed in the cardiovascular system, can exert a fine-tuned regulation of Protease activities. Among them, Protease Nexin-1 (PN-1, encoded by SERPINE2) is a very powerful thrombin inhibitor and can also inactivate plasminogen activators and plasmin. Studies have shown that this serpin is expressed by all cell subpopulations in the vascular wall and by circulating cells but is barely detectable in plasma in the free form. PN-1 present in platelet granules and released upon activation has been shown to present strong antithrombotic and antifibrinolytic properties. PN-1 has a broad spectrum of action related to both hemostatic and blood vessel wall Protease activities. Different studies showed that PN-1 is not only an important protector of vascular cells against Protease activities but also a significant actor in the clearance of the complexes it forms with its targets. In this context, PN-1 overexpression has been observed in the pathophysiology of thoracic aortic aneurysms (TAA) and during the development of atherosclerosis in humans. Similarly, in the heart, PN-1 has been shown to be overexpressed in a mouse model of heart failure and to be involved in cardiac fibrosis. Overall, PN-1 appears to serve as a "hand brake" for Protease activities during cardiovascular remodeling. This review will thus highlight the role of PN-1 in the cardiovascular system and deliver a comprehensive assessment of its position among serpins.
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in vitro and in vivo antiangiogenic properties of the serpin Protease Nexin 1
Molecular and Cellular Biology, 2012Co-Authors: Sonia Selbonne, Mariechristine Bouton, Yacine Boulaftali, Benjamin Richard, Martine Jandrotperrus, Feriel Azibani, Soria Iatmanen, Veronique ArocasAbstract:The serpin Protease Nexin-1 (PN-1) is expressed by vascular cells and secreted by platelets upon activation, and it is known to interact with several modulators of angiogenesis, such as Proteases, matrix proteins, and glycosaminoglycans. We therefore investigated the impact of PN-1 on endothelial cell angiogenic responses in vitro and ex vivo and in vivo in PN-1-deficient mice. We found that PN-1 is antiangiogenic in vitro: it inhibited vascular endothelial growth factor (VEGF)-induced endothelial cell responses, including proliferation, migration, and capillary tube formation, and decreased cell spreading on vitronectin. These effects do not require the antiProtease activity of PN-1 but involve PN-1 binding to glycosaminoglycans. In addition, our results indicated that PN-1 does not act by blocking VEGF binding to its heparan sulfate proteoglycan coreceptors. The results obtained in vitro were supported ex vivo in PN-1-deficient mice, where the microvascular network sprouting from aortic rings was significantly enhanced. Moreover, in vivo, neovessel formation was promoted in the Matrigel plug assay in PN-1-deficient mice compared to wild-type mice, and these effects were reversed by the addition of recombinant PN-1. Taken together, our results demonstrate that PN-1 has direct antiangiogenic properties and is a yet-unrecognized player in the angiogenic balance.
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emerging role of serpine2 Protease Nexin 1 in hemostasis and vascular biology
Blood, 2012Co-Authors: Mariechristine Bouton, Yacine Boulaftali, Benjamin Richard, Veronique Arocas, Jeanbaptiste MichelAbstract:Serine Protease inhibitors, termed serpins, are key regulators in many biologic events. Protease Nexin-1 (PN-1) is a serpin that is barely detectable in plasma but found in many organs and produced by most cell types, including monocytes, platelets, and vascular cells. It has a large inhibition spectrum because it is the most efficient tissue inhibitor of thrombin but also a powerful inhibitor of plasminogen activators and plasmin. It has a high affinity for glycosaminoglycans, such as heparan sulfates, which potentiate its activity toward thrombin and target it to the pericellular space. PN-1 has been previously largely described as a crucial regulator of the proteolytic activity in nerves and of central and peripheral nervous system function. In contrast, little was known about its involvement in hemostasis and vascular biology. This article reviews recent data underlining its emerging role as a key factor in the responses of vessels to injury. Indeed, studies of PN-1–deficient mice have established important antithrombotic and antifibrinolytic properties of this serpin that have heretofore gone unrecognized. The roles of PN-1 in the areas of hemostasis and thrombosis summarized here provide insights that may allow the development of drugs and treatment strategies to prevent or limit thrombotic disorders.
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platelet Protease Nexin 1 a serpin that strongly influences fibrinolysis and thrombolysis
Circulation, 2011Co-Authors: Yacine Boulaftali, Benjamin Richard, Veronique Arocas, Benoit Hotinnoe, Ana Pena, Stephane Loyau, Laurence Venisse, Deborah Francois, Jeanphilippe Collet, Martine JandrotperrusAbstract:Background—Protease Nexin-1 (PN-1) is a serpin that inhibits plasminogen activators, plasmin, and thrombin. PN-1 is barely detectable in plasma, but we have shown recently that PN-1 is present within the α-granules of platelets. Methods and Results—In this study, the role of platelet PN-1 in fibrinolysis was investigated with the use of human platelets incubated with a blocking antibody and platelets from PN-1–deficient mice. We showed by using fibrin-agar zymography and fibrin matrix that platelet PN-1 inhibited both the generation of plasmin by fibrin-bound tissue plasminogen activator and the activity of fibrin-bound plasmin itself. Rotational thromboelastometry and laser scanning confocal microscopy were used to demonstrate that PN-1 blockade or deficiency resulted in increased clot lysis and in an acceleration of the lysis front. Protease Nexin-1 is thus a major determinant of the lysis resistance of platelet-rich clots. Moreover, in an original murine model in which thrombolysis induced by tissue pl...
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anticoagulant and antithrombotic properties of platelet Protease Nexin 1
Blood, 2010Co-Authors: Yacine Boulaftali, Benjamin Richard, Laurence Venisse, Denis Monard, Frederic Adam, Veronique Ollivier, Sabrina Taieb, Remi Favier, Mariechristine Alessi, Marijke BryckaertAbstract:Protease Nexin-1 (PN-1) is a serpin that inhibits plasminogen activators, plasmin, and thrombin. PN-1 is barely detectable in plasma but is expressed by platelets. Here, we studied platelet PN-1 in resting and activated conditions and its function in thrombosis. Studies on human platelets from healthy donors and from patients with a Gray platelet syndrome demonstrate that PN-1 is present both at the platelet surface and in alpha-granules. The role of PN-1 was investigated in vitro using human platelets incubated with a blocking antibody and using platelets from PN-1-deficient mice. Both approaches indicate that platelet PN-1 is active on thrombin and urokinase-type plasminogen activator. Blockade and deficiency of platelet PN-1 result in accelerated and increased tissue factor-induced thrombin generation as indicated by calibrated automated thrombography. Moreover, platelets from PN-1-deficient mice respond to subthreshold doses of thrombin, as assessed by P-selectin expression and platelet aggregation. Thrombus formation, induced ex vivo by collagen in blood flow conditions and in vivo by FeCl(3)-induced injury, is significantly increased in PN-1-deficient mice, demonstrating the antithrombotic properties of platelet PN-1. Platelet PN-1 is thus a key player in the thrombotic process, whose negative regulatory role has been, up to now, markedly underestimated.
Martine Jandrotperrus - One of the best experts on this subject based on the ideXlab platform.
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hematopoietic Protease Nexin 1 protects against lung injury by preventing thrombin signaling in mice
Blood Advances, 2018Co-Authors: Deborah Francois, Veronique Arocas, Martine Jandrotperrus, Laurence Venisse, Karen Aymonnier, Leila Idir, Raphael Martos, Salome L Gazit, Ludovic Couty, Eric CamererAbstract:Coagulation and fibrinolytic system deregulation has been implicated in the development of idiopathic pulmonary fibrosis, a devastating form of interstitial lung disease. We used intratracheal instillation of bleomycin to induce pulmonary fibrosis in mice and analyzed the role of serine Protease inhibitor E2 (serpinE2)/Protease Nexin-1 (PN-1), a tissue serpin that exhibits anticoagulant and antifibrinolytic properties. PN-1 deficiency was associated, after bleomycin challenge, with a significant increase in mortality, as well as a marked increase in active thrombin in bronchoalveolar lavage fluids, an overexpression of extracellular matrix proteins, and an accumulation of inflammatory cells in the lungs. Bone marrow transplantation experiments showed that protective PN-1 was derived from hematopoietic cell compartment. A pharmacological strategy using the direct thrombin inhibitor argatroban reversed the deleterious effects of PN-1 deficiency. Concomitant deficiency of the thrombin receptor Protease-activated receptor 4 (PAR4) abolished the deleterious effects of PN-1 deficiency in hematopoietic cells. These data demonstrate that prevention of thrombin signaling by PN-1 constitutes an important endogenous mechanism of protection against lung fibrosis and associated mortality. Our findings suggest that appropriate doses of thrombin inhibitors or PAR4 antagonists may provide benefit against progressive lung fibrosis with evidence of deregulated thrombin activity.
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endothelial Protease Nexin 1 is a novel regulator of a disintegrin and metalloproteinase 17 maturation and endothelial protein c receptor shedding via furin inhibition
Arteriosclerosis Thrombosis and Vascular Biology, 2013Co-Authors: Yacine Boulaftali, Veronique Arocas, Martine Jandrotperrus, Laurence Venisse, Deborah Francois, Mariechristine BoutonAbstract:Objective—Human protein C is a plasma serine Protease that plays a key role in hemostasis, and activated protein C (aPC) is known to elicit protective responses in vascular endothelial cells. This cytoprotective activity requires the interaction of the Protease with its cell membrane receptor, endothelial protein C receptor. However, the mechanisms regulating the beneficial cellular effects of aPC are not well known. We aimed to determine whether a serine Protease inhibitor called Protease Nexin-1 (PN-1) or serpinE2, expressed by vascular cells, can modulate the effect of aPC on endothelial cells. Approach and Results—We found that vascular barrier protective and antiapoptotic activities of aPC were reduced both in endothelial cells underexpressing PN-1 and in endothelial cells whose PN-1 function was blocked by a neutralizing antibody. Our in vitro data were further confirmed in vivo. Indeed, we found that vascular endothelial growth factor–mediated hyperpermeability in the skin of mice was markedly redu...
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in vitro and in vivo antiangiogenic properties of the serpin Protease Nexin 1
Molecular and Cellular Biology, 2012Co-Authors: Sonia Selbonne, Mariechristine Bouton, Yacine Boulaftali, Benjamin Richard, Martine Jandrotperrus, Feriel Azibani, Soria Iatmanen, Veronique ArocasAbstract:The serpin Protease Nexin-1 (PN-1) is expressed by vascular cells and secreted by platelets upon activation, and it is known to interact with several modulators of angiogenesis, such as Proteases, matrix proteins, and glycosaminoglycans. We therefore investigated the impact of PN-1 on endothelial cell angiogenic responses in vitro and ex vivo and in vivo in PN-1-deficient mice. We found that PN-1 is antiangiogenic in vitro: it inhibited vascular endothelial growth factor (VEGF)-induced endothelial cell responses, including proliferation, migration, and capillary tube formation, and decreased cell spreading on vitronectin. These effects do not require the antiProtease activity of PN-1 but involve PN-1 binding to glycosaminoglycans. In addition, our results indicated that PN-1 does not act by blocking VEGF binding to its heparan sulfate proteoglycan coreceptors. The results obtained in vitro were supported ex vivo in PN-1-deficient mice, where the microvascular network sprouting from aortic rings was significantly enhanced. Moreover, in vivo, neovessel formation was promoted in the Matrigel plug assay in PN-1-deficient mice compared to wild-type mice, and these effects were reversed by the addition of recombinant PN-1. Taken together, our results demonstrate that PN-1 has direct antiangiogenic properties and is a yet-unrecognized player in the angiogenic balance.
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platelet Protease Nexin 1 a serpin that strongly influences fibrinolysis and thrombolysis
Circulation, 2011Co-Authors: Yacine Boulaftali, Benjamin Richard, Veronique Arocas, Benoit Hotinnoe, Ana Pena, Stephane Loyau, Laurence Venisse, Deborah Francois, Jeanphilippe Collet, Martine JandrotperrusAbstract:Background—Protease Nexin-1 (PN-1) is a serpin that inhibits plasminogen activators, plasmin, and thrombin. PN-1 is barely detectable in plasma, but we have shown recently that PN-1 is present within the α-granules of platelets. Methods and Results—In this study, the role of platelet PN-1 in fibrinolysis was investigated with the use of human platelets incubated with a blocking antibody and platelets from PN-1–deficient mice. We showed by using fibrin-agar zymography and fibrin matrix that platelet PN-1 inhibited both the generation of plasmin by fibrin-bound tissue plasminogen activator and the activity of fibrin-bound plasmin itself. Rotational thromboelastometry and laser scanning confocal microscopy were used to demonstrate that PN-1 blockade or deficiency resulted in increased clot lysis and in an acceleration of the lysis front. Protease Nexin-1 is thus a major determinant of the lysis resistance of platelet-rich clots. Moreover, in an original murine model in which thrombolysis induced by tissue pl...
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macrophages and platelets are the major source of Protease Nexin 1 in human atherosclerotic plaque
Arteriosclerosis Thrombosis and Vascular Biology, 2008Co-Authors: Silvana Mansilla, Yacine Boulaftali, Veronique Arocas, Jeanbaptiste Michel, Martine Jandrotperrus, Olivier Meilhac, Laurence Venisse, Mariechristine BoutonAbstract:Objective— Protease Nexin-1 (PN-1), a serpin constitutively expressed by vascular smooth muscle cells and endothelial cells, inhibits thrombin, plasminogen activators, and plasmin and can thus be expected to play a role in vascular biology. The present study addressed the question of PN-1 expression in human atherothrombosis. Methods and Results— Immunohistochemistry and biochemical studies confirmed that PN-1 was expressed at a moderate level in the medial layer of normal human arteries and showed that PN-1 expression was increased in atherothrombotic lesions. In early noncomplicated plaques, PN-1 was associated with infiltrating mononuclear cells. A strong PN-1 signal was observed in advanced lesions, principally in intraplaque hemorrhage-related structures. Monocytes/macrophages and platelets were identified as the main sources of PN-1 within atherothrombotic material. Isolated human monocytes and platelets both expressed high levels of active PN-1, and monocyte PN-1 expression was upregulated, at both messenger and protein levels, in response to stimulation by lipopolysaccharides. In contrast, PN-1 expression was downregulated during their differentiation into macrophages which were shown to produce degraded forms of PN-1. Conclusions— Platelets and monocytes/macrophages are a major source of PN-1 in human atherothrombotic plaques. PN-1 could thus represent a new actor in the evolution of atherosclerotic lesions.
