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Fenclova T, Matyskova M, Provaznikova D, Marecek F, Geierova V, Kovarova-Kudrnova Z, Hrachovinova I. The impact of PROS1 mutation position on thrombotic risk in protein S-deficient patients. Res Pract Thromb Haemost 2023; 7:100194. [PMID: 37384225 PMCID: PMC10293767 DOI: 10.1016/j.rpth.2023.100194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 05/16/2023] [Indexed: 06/30/2023] Open
Abstract
Background Inherited protein S deficiency is a thrombophilic risk factor associated with venous thromboembolism. However, there is not much data on the impact of mutation position on thrombotic risk. Objectives The aim of this study was to evaluate the risk of thrombosis due to mutations located in the sex hormone-binding globulin (SHBG)-like region as opposed to the rest of the protein. Methods Genetic analysis of PROS1 was performed in 76 patients with suspected inherited protein S deficiency, and the effect of missense mutations present in the SHBG region on thrombosis risk was analyzed by statistical methods. Results We found 30 unique mutations (13 of them novel), of which 17 were missense mutations, in 70 patients. Patients with missense mutations were then divided into 2 groups: the "SHBG-region" mutation group (27 patients) and the "non-SHBG" group (24 patients). The multivariable binary logistic regression analysis showed that mutation position in the SHBG region of protein S is an independent risk factor for thrombosis in deficient patients (OR, 5.17; 95% CI, 1.29-20.65; P = .02). The patients with a mutation in the SHBG-like region also developed a thrombotic event at a younger age compared to the "non-SHBG" group in the Kaplan-Meier analysis (median thrombosis-free survival of 33 vs 47 years, respectively; P = .018). Conclusion Our findings show that a missense mutation located in the SHBG-like region may contribute to higher thrombotic risk rather than a missense mutation located elsewhere in the protein. However, as our cohort was relatively small, these findings should be taken with this limitation.
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Affiliation(s)
- Tereza Fenclova
- First Faculty of Medicine, Charles University, Prague, Czech Republic
- Institute of Hematology and Blood Transfusion, National Reference Laboratory for Disorders in Hemostasis, Prague, Czech Republic
| | | | - Dana Provaznikova
- Institute of Hematology and Blood Transfusion, National Reference Laboratory for Disorders in Hemostasis, Prague, Czech Republic
| | - Frantisek Marecek
- Institute of Hematology and Blood Transfusion, National Reference Laboratory for Disorders in Hemostasis, Prague, Czech Republic
| | - Vera Geierova
- Institute of Hematology and Blood Transfusion, Centre for Thrombosis and Hemostasis, Prague, Czech Republic
| | - Zuzana Kovarova-Kudrnova
- Thrombotic Centre of Institute of Medical Biochemistry and Laboratory Diagnostics, General University Hospital, Prague, Czech Republic
| | - Ingrid Hrachovinova
- Institute of Hematology and Blood Transfusion, National Reference Laboratory for Disorders in Hemostasis, Prague, Czech Republic
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2
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Sedzro JC, Adam F, Auditeau C, Bianchini E, De Carvalho A, Peyron I, Daramé S, Gandrille S, Thomassen S, Hackeng TM, Christophe OD, Lenting PJ, Denis CV, Borgel D, Saller F. Antithrombotic potential of a single-domain antibody enhancing the activated protein C-cofactor activity of protein S. J Thromb Haemost 2022; 20:1653-1664. [PMID: 35445541 DOI: 10.1111/jth.15736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/05/2022] [Accepted: 04/19/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Protein S (PS) is a natural anticoagulant acting as a cofactor for activated protein C (APC) in the proteolytic inactivation of activated factors V (FVa) and VIII (FVIIIa), but also for tissue factor pathway inhibitor α (TFPIα) in the inhibition of activated factor X (FXa). OBJECTIVE For therapeutic purposes, we aimed at generating single-domain antibodies (sdAbs) that could specifically modulate the APC-cofactor activity of PS in vivo. METHODS A llama-derived immune library of sdAbs was generated and screened on recombinant human PS by phage display. PS binders were tested in a global activated partial thromboplastin time (APTT)-based APC-cofactor activity assay. RESULTS A PS-specific sdAb (PS003) was found to enhance the APC-cofactor activity of PS in our APTT-based assay, and this enhancing effect was greater for a bivalent form of PS003 (PS003biv). Further characterization of PS003biv demonstrated that PS003biv also enhanced the APC-cofactor activity of PS in a tissue factor (TF)-induced thrombin generation assay and stimulated APC in the inactivation of FVa, but not FVIIIa, in plasma-based assays. Furthermore, PS003biv was directed against the sex hormone-binding globulin (SHBG)-like domain but did not inhibit the binding of PS to C4b-binding protein (C4BP) and did not interfere with the TFPIα-cofactor activity of PS. In mice, PS003biv exerted an antithrombotic effect in a FeCl3 -induced thrombosis model, while not affecting physiological hemostasis in a tail-clip bleeding model. DISCUSSION Altogether, these results showed that pharmacological enhancement of the APC-cofactor activity of PS through an original anti-PS sdAb might constitute a promising and safe antithrombotic strategy.
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Affiliation(s)
- Josepha C Sedzro
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Frédéric Adam
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Claire Auditeau
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- Service d'Hématologie Biologique, Hôpital Necker Enfants Malades, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Elsa Bianchini
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Allan De Carvalho
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Ivan Peyron
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Sadyo Daramé
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Sophie Gandrille
- Innovations Thérapeutiques en Hémostase, UMR-S1140, INSERM, Université de Paris, Paris, France
- Service d'Hématologie Biologique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - Stella Thomassen
- Cardiovascular Research Institute Maastricht (CARIM), University Maastricht, Maastricht, the Netherlands
| | - Tilman M Hackeng
- Cardiovascular Research Institute Maastricht (CARIM), University Maastricht, Maastricht, the Netherlands
| | - Olivier D Christophe
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Peter J Lenting
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Cécile V Denis
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Delphine Borgel
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- Service d'Hématologie Biologique, Hôpital Necker Enfants Malades, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
| | - François Saller
- Hémostase, Inflammation, Thrombose (HITh), UMR-S1176, INSERM, Université Paris-Saclay, Le Kremlin-Bicêtre, France
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Gas6/TAM Axis in Sepsis: Time to Consider Its Potential Role as a Therapeutic Target. DISEASE MARKERS 2019; 2019:6156493. [PMID: 31485279 PMCID: PMC6710761 DOI: 10.1155/2019/6156493] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022]
Abstract
Tyrosine kinase receptors are transmembrane proteins involved in cell signaling and interaction. Among them, the TAM family (composed by Tyro 3, Axl, and Mer) represents a peculiar subgroup with an important role in many physiological and pathological conditions. Despite different mechanisms of activation (e.g., protein S and Galactin-3), TAM action is tightly related to their common ligand, a protein named growth arrest-specific 6 (Gas6). Since the expression of both TAM and Gas6 is widely distributed among tissues, any alteration of one of these components can lead to different pathological conditions. Moreover, as they are indispensable for homeostasis maintenance, in recent years a growing interest has emerged regarding their role in the regulation of the inflammatory process. Due to this involvement, many authors have demonstrated the pivotal role of the Gas6/TAM axis in both sepsis and the sepsis-related inflammatory responses. In this narrative review, we highlight the current knowledge as well as the last discoveries on TAM and Gas6 implication in different clinical conditions, notably in sepsis and septic shock. Lastly, we underline not only the feasible use of Gas6 as a diagnostic and prognostic biomarker in certain systemic acute conditions but also its potential therapeutic role in these life-threatening diseases.
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4
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Sato Y, Sugi T, Sakai R. Antigenic binding sites of anti-protein S autoantibodies in patients with recurrent pregnancy loss. Res Pract Thromb Haemost 2018; 2:357-365. [PMID: 30046739 PMCID: PMC6055483 DOI: 10.1002/rth2.12081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/02/2018] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Protein S (PS) deficiency is a risk factor for adverse pregnancy outcomes including recurrent pregnancy loss. Several studies have shown that the presence of anti-PS autoantibodies (anti-PS) leads to an acquired PS deficiency. Hence, an epitope mapping study was conducted to know the pathogenesis of anti-PS in patients with recurrent pregnancy loss. METHODS PS was treated with thrombin to divide the protein into γ-carboxyglutamic acid (Gla) domain and Gla-domain free PS. For the preparation of fragments of epidermal growth factor (EGF)-like domains (EGF1-4), PS was subjected to proteolysis using lysyl endopeptidase. The epitopes were identified in immunoblot. Whether anti-PS recognized EGF family proteins in anti-PS-positive patients was also examined. RESULTS Anti-PS recognized Gla-domain free PS, especially the three fragments of EGF-like domains, EGF1-2, EGF3-4, and EGF1-4. Anti-PS recognized recombinant human EGF. Anti-PS and polyclonal antibodies to recombinant human EGF recognized PS in the absence of Ca2+ but not in the presence of Ca2+. In competitive inhibition studies, polyclonal antibodies to recombinant mouse EGF blocked anti-PS binding to PS in a concentration-dependent manner. CONCLUSIONS These results suggest that anti-PS in patients with recurrent pregnancy loss recognize EGF-like domains in PS. Interestingly, anti-PS also recognized EGF family proteins. Anti-PS in patients with recurrent pregnancy loss may be associated with not only thrombophilia but also the disruption of the EGF system.
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Affiliation(s)
- Yoshihiro Sato
- Laboratory for Recurrent Pregnancy LossSugi Women's ClinicYokohamaJapan
| | - Toshitaka Sugi
- Laboratory for Recurrent Pregnancy LossSugi Women's ClinicYokohamaJapan
| | - Rie Sakai
- Laboratory for Recurrent Pregnancy LossSugi Women's ClinicYokohamaJapan
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Studer RA, Opperdoes FR, Nicolaes GAF, Mulder AB, Mulder R. Understanding the functional difference between growth arrest-specific protein 6 and protein S: an evolutionary approach. Open Biol 2015; 4:rsob.140121. [PMID: 25339693 PMCID: PMC4221892 DOI: 10.1098/rsob.140121] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Although protein S (PROS1) and growth arrest-specific protein 6 (GAS6) proteins are homologous with a high degree of structural similarity, they are functionally different. The objectives of this study were to identify the evolutionary origins from which these functional differences arose. Bioinformatics methods were used to estimate the evolutionary divergence time and to detect the amino acid residues under functional divergence between GAS6 and PROS1. The properties of these residues were analysed in the light of their three-dimensional structures, such as their stability effects, the identification of electrostatic patches and the identification potential protein-protein interaction. The divergence between GAS6 and PROS1 probably occurred during the whole-genome duplications in vertebrates. A total of 78 amino acid sites were identified to be under functional divergence. One of these sites, Asn463, is involved in N-glycosylation in GAS6, but is mutated in PROS1, preventing this post-translational modification. Sites experiencing functional divergence tend to express a greater diversity of stabilizing/destabilizing effects than sites that do not experience such functional divergence. Three electrostatic patches in the LG1/LG2 domains were found to differ between GAS6 and PROS1. Finally, a surface responsible for protein-protein interactions was identified. These results may help researchers to analyse disease-causing mutations in the light of evolutionary and structural constraints, and link genetic pathology to clinical phenotypes.
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Affiliation(s)
- Romain A Studer
- European Molecular Biology Laboratory-European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - Fred R Opperdoes
- Laboratory of Biochemistry, de Duve Institute and Université catholique de Louvain, Brussels 1200, Belgium
| | - Gerry A F Nicolaes
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - André B Mulder
- Department of Laboratory Medicine, University Medical Centre Groningen, Groningen, The Netherlands
| | - René Mulder
- Department of Laboratory Medicine, University Medical Centre Groningen, Groningen, The Netherlands
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6
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Somajo S, Ahnström J, Fernandez-Recio J, Gierula M, Villoutreix BO, Dahlbäck B. Amino acid residues in the laminin G domains of protein S involved in tissue factor pathway inhibitor interaction. Thromb Haemost 2015; 113:976-87. [PMID: 25716664 DOI: 10.1160/th14-09-0803] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 01/05/2015] [Indexed: 11/05/2022]
Abstract
Protein S functions as a cofactor for tissue factor pathway inhibitor (TFPI) and activated protein C (APC). The sex hormone binding globulin (SHBG)-like region of protein S, consisting of two laminin G-like domains (LG1 and LG2), contains the binding site for C4b-binding protein (C4BP) and TFPI. Furthermore, the LG-domains are essential for the TFPI-cofactor function and for expression of full APC-cofactor function. The aim of the current study was to localise functionally important interaction sites in the protein S LG-domains using amino acid substitutions. Four protein S variants were created in which clusters of surface-exposed amino acid residues within the LG-domains were substituted. All variants bound normally to C4BP and were fully functional as cofactors for APC in plasma and in pure component assays. Two variants, SHBG2 (E612A, I614A, F265A, V393A, H453A), involving residues from both LG-domains, and SHBG3 (K317A, I330A, V336A, D365A) where residues in LG1 were substituted, showed 50-60 % reduction in enhancement of TFPI in FXa inhibition assays. For SHBG3 the decreased TFPI cofactor function was confirmed in plasma based thrombin generation assays. Both SHBG variants bound to TFPI with decreased affinity in surface plasmon resonance experiments. The TFPI Kunitz 3 domain is known to contain the interaction site for protein S. Using in silico analysis and protein docking exercises, preliminary models of the protein S SHBG/TFPI Kunitz domain 3 complex were created. Based on a combination of experimental and in silico data we propose a binding site for TFPI on protein S, involving both LG-domains.
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Affiliation(s)
| | | | | | | | | | - Björn Dahlbäck
- Björn Dahlbäck MD, PhD, Professor of Blood Coagulation Research, Lund University, Department of Translational Medicine, Division of Clinical Chemistry, Wallenberg laboratory, floor 6, University Hospital, Malmö, S-20502 Malmö, Sweden, E-mail:
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7
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Clauser S, Meilhac O, Bièche I, Raynal P, Bruneval P, Michel JB, Borgel D. Increased secretion of Gas6 by smooth muscle cells in human atherosclerotic carotid plaques. Thromb Haemost 2011; 107:140-9. [PMID: 22072012 DOI: 10.1160/th11-05-0368] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 10/04/2011] [Indexed: 12/14/2022]
Abstract
Vitamin K-dependent protein Gas6 (growth-arrest specific gene 6) plays a role in vascular smooth muscle cell (VSMC) survival and migration, as well as in endothelium and leukocyte activation, and could therefore be involved in atherosclerosis. However, the study of mouse models has led to contradictory results regarding the pro- or anti-atherogenic properties of Gas6, and relatively few data are available in human pathophysiology. To better understand the implication of Gas6 in human atherosclerosis, we studied Gas6 expression and secretion in vitro in human VSMC, and analysed the effect of Gas6 on inflammatory gene expression in these cells. We show that Gas6 secretion in VSMC is strongly induced by the anti-inflammatory cytokine transforming growth factor (TGF)β, and that VSMC stimulation by recombinant Gas6 decreases the expression of inflammatory genes tumour necrosis factor (TNF)α and intracellular adhesion molecule (ICAM)-1. The study of Gas6 expression in human carotid endarterectomy samples revealed that Gas6 is mainly expressed by VSMC at all stages of human atherosclerosis, but is not detected in normal vessel wall. Analysis of plaque secretomes showed that Gas6 secretion is markedly higher in non-complicated plaques than in complicated plaques, and that TGFβ secretion pattern mirrors that of Gas6. We conclude that Gas6 is secreted in human atherosclerotic plaques by VSMC following stimulation by TGFβ, and that Gas6 secretion decreases with plaque complication. Therefore, we propose that Gas6 acts as a protective factor, in part by reducing the pro-inflammatory phenotype of VSMC.
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8
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Zhong Z, Wang Y, Guo H, Sagare A, Fernández JA, Bell RD, Barrett TM, Griffin JH, Freeman RS, Zlokovic BV. Protein S protects neurons from excitotoxic injury by activating the TAM receptor Tyro3-phosphatidylinositol 3-kinase-Akt pathway through its sex hormone-binding globulin-like region. J Neurosci 2010; 30:15521-34. [PMID: 21084607 PMCID: PMC3012432 DOI: 10.1523/jneurosci.4437-10.2010] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 09/15/2010] [Indexed: 11/21/2022] Open
Abstract
The anticoagulant factor protein S (PS) protects neurons from hypoxic/ischemic injury. However, molecular mechanisms mediating PS protection in injured neurons remain unknown. Here, we show mouse recombinant PS protects dose-dependently mouse cortical neurons from excitotoxic NMDA-mediated neuritic bead formation and apoptosis by activating the phosphatidylinositol 3-kinase (PI3K)-Akt pathway (EC(50) = 26 ± 4 nm). PS stimulated phosphorylation of Bad and Mdm2, two downstream targets of Akt, which in neurons subjected to pathological overstimulation of NMDA receptors (NMDARs) increased the antiapoptotic Bcl-2 and Bcl-X(L) levels and reduced the proapoptotic p53 and Bax levels. Adenoviral transduction with a kinase-deficient Akt mutant (Ad.Akt(K179A)) resulted in loss of PS-mediated neuronal protection, Akt activation, and Bad and Mdm2 phosphorylation. Using the TAM receptors tyrosine kinases Tyro3-, Axl-, and Mer-deficient neurons, we showed that PS protected neurons lacking Axl and Mer, but not Tyro3, suggesting a requirement of Tyro3 for PS-mediated protection. Consistent with these results, PS dose-dependently phosphorylated Tyro3 on neurons (EC(50) = 25 ± 3 nm). In an in vivo model of NMDA-induced excitotoxic lesions in the striatum, PS dose-dependently reduced the lesion volume in control mice (EC(50) = 22 ± 2 nm) and protected Axl(-/-) and Mer(-/-) transgenic mice, but not Tyro3(-/-) transgenic mice. Using different structural PS analogs, we demonstrated that the C terminus sex hormone-binding globulin-like (SHBG) domain of PS is critical for neuronal protection in vitro and in vivo. Thus, our data show that PS protects neurons by activating the Tyro3-PI3K-Akt pathway via its SHGB domain, suggesting potentially a novel neuroprotective approach for acute brain injury and chronic neurodegenerative disorders associated with excessive activation of NMDARs.
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Affiliation(s)
- Zhihui Zhong
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Yaoming Wang
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Huang Guo
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Abhay Sagare
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - José A. Fernández
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Robert D. Bell
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - Theresa M. Barrett
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
| | - John H. Griffin
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037
| | - Robert S. Freeman
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, New York 14642, and
| | - Berislav V. Zlokovic
- Center for Neurodegenerative and Vascular Brain Disorders, Department of Neurosurgery and Neurology, and
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9
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Alternative mRNA is favored by the A3 haplotype of the EPCR gene PROCR and generates a novel soluble form of EPCR in plasma. Blood 2007; 111:3442-51. [PMID: 18073349 DOI: 10.1182/blood-2007-08-104968] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The endothelial cell protein C receptor also exists in soluble form in plasma (sEPCR), resulting from ADAM17 cleavage. Elevated sEPCR levels are observed in subjects carrying the A3 haplotype, which is characterized by a Ser219Gly substitution in the transmembrane domain, rendering the receptor more sensitive to cleavage. Because sEPCR production is not completely blocked by metalloprotease inhibition, we looked for another mechanism. Comparing mRNA expression patterns and levels in A3 and non-A3 cells from 32 human umbilical cord veins, we detected a truncated mRNA in addition to the full-length mRNA. This truncated mRNA was 16 times more abundant in A3 human umbilical vein endothelial cells than in non-A3 human umbilical vein endothelial cells and encoded a protein lacking the transmembrane domain. We stably expressed a recombinant form of this protein (rEPCRisoform) and a protein mimicking the plasma sEPCR (rEPCRsol). Functional studies of the purified recombinant proteins revealed that the rEPCRisoform bound to recombinant protein C with similar affinity than rEPCRsol and that it also inhibited the anticoagulant activity of APC. Trace amounts of the EPCR isoform were found in the plasma of A3 subjects. These results suggest that the sEPCRisoform could contribute to the regulatory effect of sEPCR in plasma.
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10
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Clauser S, Peyrard S, Gaussem P, Crespin M, Emmerich J, Aiach M, Borgel D. Development of a Novel Immunoassay for the Assessment of Plasma Gas6 Concentrations and Their Variation with Hormonal Status. Clin Chem 2007; 53:1808-13. [PMID: 17717130 DOI: 10.1373/clinchem.2007.089102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract
Background: Gas6 is a vitamin K–dependent antiapoptotic protein that has been implicated in cardiovascular pathophysiology. We report the development and validation of an ELISA for Gas6, and the variation of plasma Gas6 with hormonal status in a study designed to evaluate the effect of oral contraception on plasma markers.
Methods: After validation of the main stages of the ELISA assay, we measured plasma Gas6 concentrations in 94 male and 88 female healthy volunteers ages 18 to 38 years. Forty-five of the women then received an oral contraceptive, which contained ethinylestradiol and levonorgestrel, for 3 months before a new measurement was performed at the same time point in their menstrual cycles.
Results: Interassay imprecision was 5.8%–11.8%, and the detection limit was 5.9 μg/L. Mean Gas6 plasma concentrations were significantly lower in men (52.0 μg/L) than in women not receiving oral contraceptives (63.8 μg/L, P <0.001). In the women who received oral contraceptives, Gas6 concentrations decreased after 3 months of therapy from 63.6 μg/L to 51.9 μg/L (P <0.001).
Conclusions: We have developed a simple and reproducible ELISA assay for measuring plasma Gas6 concentrations, which vary with sex and are decreased by oral contraceptive use. These results suggest regulation of plasma Gas6 concentrations by sex hormones. Future clinical studies may require participants to be stratified by sex.
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Affiliation(s)
- Sylvain Clauser
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service d'Hématologie Biologique A, Paris, France
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11
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Saller F, Kaabache T, Aiach M, Gandrille S, Borgel D. The protein S thrombin-sensitive region modulates phospholipid binding and the gamma-carboxyglutamic acid-rich (Gla) domain conformation in a non-specific manner. J Thromb Haemost 2006; 4:704-6. [PMID: 16460467 DOI: 10.1111/j.1538-7836.2006.01827.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Borgel D, Clauser S, Bornstain C, Bièche I, Bissery A, Remones V, Fagon JY, Aiach M, Diehl JL. Elevated growth-arrest-specific protein 6 plasma levels in patients with severe sepsis. Crit Care Med 2006; 34:219-22. [PMID: 16374177 DOI: 10.1097/01.ccm.0000195014.56254.8a] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Growth-arrest-specific protein 6 (Gas6), an intracellular protein released by apoptotic cells, has been detected in normal plasma. As the Gas6 system has been implicated in mouse susceptibility to sepsis, and as leukocyte apoptosis is thought to play a major role in the physiopathology of human severe sepsis, we studied Gas6 plasma levels and possibly related variables in patients with severe sepsis. DESIGN Matched case-control study. SETTING Adult intensive care unit in a university hospital. PATIENTS Thirty patients with severe sepsis, 30 patients with organ failure not related to infection, and 30 healthy subjects matched for age and gender. INTERVENTIONS Blood draw. MEASUREMENTS AND MAIN RESULTS Gas6 plasma levels were quantified using enzyme-linked immunosorbent assay. Whole-blood gas6 messenger RNA levels were measured by quantitative real-time polymerase chain reaction. Gas6 plasma levels were elevated (110 ng/mL [75, 139]; median values [interquartile range]) in severe sepsis patients compared with organ failure patients (85 ng/mL [56, 101]) and healthy subjects (54 ng/mL [49, 68]). In patients with severe sepsis, this increase correlated with the Acute Physiology and Chronic Health Evaluation II severity score, the organ failure Organ Dysfunction and Infection (ODIN) score, and the existence of a septic shock. Gas6 messenger RNA levels were increased in patients with severe sepsis and correlated specifically with the monocyte count. CONCLUSIONS In severe sepsis, the recently described anti-apoptotic protein Gas6 was found at high levels in plasma and correlated well with the degree of organ dysfunction.
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Affiliation(s)
- Delphine Borgel
- Inserm U428, Service d'Hématologie Biologique A, Hôpital Européen Georges Pompidou, Paris, France.
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Ng KM, So MT, Lee WM. Expression of rabbit sex hormone-binding globulin during pregnancy and prenatal development and identification of a novel isoform. Endocrinology 2005; 146:1965-72. [PMID: 15625245 DOI: 10.1210/en.2004-1173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
SHBG is a homodimeric plasma glycoprotein. It functions as a carrier for sex steroids in blood and regulates their access to target cells. In human and rabbit, SHBG is a single-copy gene comprised of eight exons and is expressed primarily in the liver and testis. In the present study, the ontogeny of rabbit SHBG (rbSHBG) gene expression was examined in both fetus and mothers. Trace amounts of rbSHBG mRNA were detected in fetal liver from d 11 to d 29 gestation. These levels increased dramatically at d 30 and remained high until parturition (d 33). In contrast, high levels of rbSHBG mRNA were detected in the maternal liver early during pregnancy, with maximal levels being attained by d 22 and declining markedly thereafter. A rbSHBG transcript lacking the exon 4 sequences was consistently expressed along with the rbSHBG mRNA. When expressed as a glutathione-S-transferase-fusion protein, this alternatively spliced rbSHBG transcript resulted in a product with almost no steroid binding activity, unlike the full-length rbSHBG-glutathione-S-transferase fusion protein, which bound 5alpha-dihydrotestosterone. Antibody specific to the novel rbSHBG isoform lacking the exon 4-encoding domain was raised, and a single immunoreactive protein of 33-35 kDa was detected by Western blot analysis in both fetal and maternal liver, and this indicates that the rbSHBG transcripts lacking exon 4 sequences are translated in vivo. An RT-PCR analysis further revealed that this alternatively spliced SHBG transcript is present in human HepG2 cells as well as human and mouse testes, indicating that exon 4 splicing in SHBG transcription is conserved among mammalian species. To our knowledge, this is the first report of the identification of a SHBG exon 4 splice variant that is translated. Because the SHBG isoform it encodes lacks appreciable steroid-binding activity, it may function beyond that of the widely accepted role of SHBG as a steroid-transport protein.
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Affiliation(s)
- Kwong-Man Ng
- Department of Zoology, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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Saller F, Villoutreix BO, Amelot A, Kaabache T, Le Bonniec BF, Aiach M, Gandrille S, Borgel D. The γ-carboxyglutamic acid domain of anticoagulant protein S is involved in activated protein C cofactor activity, independently of phospholipid binding. Blood 2005; 105:122-30. [PMID: 15308562 DOI: 10.1182/blood-2004-06-2176] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractWe expressed 2 chimeras between human protein S (PS) and human prothrombin (FII) in which the prothrombin γ-carboxyglutamic acid (Gla) domain replaced the PS Gla domain in native PS (GlaFII-PS) or in PS deleted of the thrombin-sensitive region (TSR) (GlaFII-ΔTSR-PS). Neither PS/FII chimera had activated protein C (APC) cofactor activity in plasma clotting assays or purified systems, but both bound efficiently to phospholipids. This pointed to a direct involvement of the PS Gla domain in APC cofactor activity through molecular interaction with APC. Using computational methods, we identified 2 opposite faces of solvent-exposed residues on the PS Gla domain (designated faces 1 and 2) as potentially involved in this interaction. Their importance was supported by functional characterization of a PS mutant in which the face 1 and face 2 PS residues were reintroduced into GlaFII-PS, leading to significant APC cofactor activity, likely through restored interaction with APC. Furthermore, by characterizing PS mutants in which PS face 1 and PS face 2 were individually replaced by the corresponding prothrombin faces, we found that face 1 was necessary for efficient phospholipid binding but that face 2 residues were not strictly required for phospholipid binding and were involved in the interaction with APC.
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Affiliation(s)
- François Saller
- Institut Natioanl de la Santé et de la Recherche Médicale U428, Faculté des Sciences Pharmaceutique et Biologiques, IFR 71 Sciences du Médicament, Université Paris V, France
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15
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Rezende SM, Simmonds RE, Lane DA. Coagulation, inflammation, and apoptosis: different roles for protein S and the protein S-C4b binding protein complex. Blood 2004; 103:1192-201. [PMID: 12907438 DOI: 10.1182/blood-2003-05-1551] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Protein S (PS) has an established role as an important cofactor to activated protein C (APC) in the degradation of coagulation cofactors Va and VIIIa. This anticoagulant role is evident from the consequences of its deficiency, when there is an increased risk of venous thromboembolism. In human plasma, PS circulates approximately 40% as free PS (FPS) and 60% in complex with C4b-binding protein (C4BP). Formation of this complex results in loss of PS cofactor function, and C4BP can then modulate the anticoagulant activity of APC. It had long been predicted that the complex could act as a bridge between coagulation and inflammation due to the involvement of C4BP in regulating complement activation. This prediction was recently supported by the demonstration of binding of the PS-C4BP complex to apoptotic cells. This review aims to summarize recent findings on the structure and functions of PS, the basis and importance of its deficiency, its interaction with C4BP, and the possible physiologic and pathologic importance of the PS-C4BP interaction.
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Affiliation(s)
- Suely Meireles Rezende
- Research Laboratory, Fundação HEMOMINAS, Alameda Ezequiel Dias, 321 Belo Horizonte-MG-Brazil, 30130-110.
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